1 /* 2 ** 2001-09-15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the SQLite library 13 ** presents to client programs. If a C-function, structure, datatype, 14 ** or constant definition does not appear in this file, then it is 15 ** not a published API of SQLite, is subject to change without 16 ** notice, and should not be referenced by programs that use SQLite. 17 ** 18 ** Some of the definitions that are in this file are marked as 19 ** "experimental". Experimental interfaces are normally new 20 ** features recently added to SQLite. We do not anticipate changes 21 ** to experimental interfaces but reserve the right to make minor changes 22 ** if experience from use "in the wild" suggest such changes are prudent. 23 ** 24 ** The official C-language API documentation for SQLite is derived 25 ** from comments in this file. This file is the authoritative source 26 ** on how SQLite interfaces are supposed to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef SQLITE3_H 34 #define SQLITE3_H 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Facilitate override of interface linkage and calling conventions. 47 ** Be aware that these macros may not be used within this particular 48 ** translation of the amalgamation and its associated header file. 49 ** 50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the 51 ** compiler that the target identifier should have external linkage. 52 ** 53 ** The SQLITE_CDECL macro is used to set the calling convention for 54 ** public functions that accept a variable number of arguments. 55 ** 56 ** The SQLITE_APICALL macro is used to set the calling convention for 57 ** public functions that accept a fixed number of arguments. 58 ** 59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated. 60 ** 61 ** The SQLITE_CALLBACK macro is used to set the calling convention for 62 ** function pointers. 63 ** 64 ** The SQLITE_SYSAPI macro is used to set the calling convention for 65 ** functions provided by the operating system. 66 ** 67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and 68 ** SQLITE_SYSAPI macros are used only when building for environments 69 ** that require non-default calling conventions. 70 */ 71 #ifndef SQLITE_EXTERN 72 # define SQLITE_EXTERN extern 73 #endif 74 #ifndef SQLITE_API 75 # define SQLITE_API 76 #endif 77 #ifndef SQLITE_CDECL 78 # define SQLITE_CDECL 79 #endif 80 #ifndef SQLITE_APICALL 81 # define SQLITE_APICALL 82 #endif 83 #ifndef SQLITE_STDCALL 84 # define SQLITE_STDCALL SQLITE_APICALL 85 #endif 86 #ifndef SQLITE_CALLBACK 87 # define SQLITE_CALLBACK 88 #endif 89 #ifndef SQLITE_SYSAPI 90 # define SQLITE_SYSAPI 91 #endif 92 93 /* 94 ** These no-op macros are used in front of interfaces to mark those 95 ** interfaces as either deprecated or experimental. New applications 96 ** should not use deprecated interfaces - they are supported for backwards 97 ** compatibility only. Application writers should be aware that 98 ** experimental interfaces are subject to change in point releases. 99 ** 100 ** These macros used to resolve to various kinds of compiler magic that 101 ** would generate warning messages when they were used. But that 102 ** compiler magic ended up generating such a flurry of bug reports 103 ** that we have taken it all out and gone back to using simple 104 ** noop macros. 105 */ 106 #define SQLITE_DEPRECATED 107 #define SQLITE_EXPERIMENTAL 108 109 /* 110 ** Ensure these symbols were not defined by some previous header file. 111 */ 112 #ifdef SQLITE_VERSION 113 # undef SQLITE_VERSION 114 #endif 115 #ifdef SQLITE_VERSION_NUMBER 116 # undef SQLITE_VERSION_NUMBER 117 #endif 118 119 /* 120 ** CAPI3REF: Compile-Time Library Version Numbers 121 ** 122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 123 ** evaluates to a string literal that is the SQLite version in the 124 ** format "X.Y.Z" where X is the major version number (always 3 for 125 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 128 ** numbers used in [SQLITE_VERSION].)^ 129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 130 ** be larger than the release from which it is derived. Either Y will 131 ** be held constant and Z will be incremented or else Y will be incremented 132 ** and Z will be reset to zero. 133 ** 134 ** Since [version 3.6.18] ([dateof:3.6.18]), 135 ** SQLite source code has been stored in the 136 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 138 ** a string which identifies a particular check-in of SQLite 139 ** within its configuration management system. ^The SQLITE_SOURCE_ID 140 ** string contains the date and time of the check-in (UTC) and a SHA1 141 ** or SHA3-256 hash of the entire source tree. If the source code has 142 ** been edited in any way since it was last checked in, then the last 143 ** four hexadecimal digits of the hash may be modified. 144 ** 145 ** See also: [sqlite3_libversion()], 146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 147 ** [sqlite_version()] and [sqlite_source_id()]. 148 */ 149 #define SQLITE_VERSION "3.40.0" 150 #define SQLITE_VERSION_NUMBER 3040000 151 #define SQLITE_SOURCE_ID "2022-11-16 12:10:08 89c459e766ea7e9165d0beeb124708b955a4950d0f4792f457465d71b158d318" 152 153 /* 154 ** CAPI3REF: Run-Time Library Version Numbers 155 ** KEYWORDS: sqlite3_version sqlite3_sourceid 156 ** 157 ** These interfaces provide the same information as the [SQLITE_VERSION], 158 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 159 ** but are associated with the library instead of the header file. ^(Cautious 160 ** programmers might include assert() statements in their application to 161 ** verify that values returned by these interfaces match the macros in 162 ** the header, and thus ensure that the application is 163 ** compiled with matching library and header files. 164 ** 165 ** <blockquote><pre> 166 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 167 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 168 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 169 ** </pre></blockquote>)^ 170 ** 171 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 172 ** macro. ^The sqlite3_libversion() function returns a pointer to the 173 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 174 ** function is provided for use in DLLs since DLL users usually do not have 175 ** direct access to string constants within the DLL. ^The 176 ** sqlite3_libversion_number() function returns an integer equal to 177 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 178 ** a pointer to a string constant whose value is the same as the 179 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 180 ** using an edited copy of [the amalgamation], then the last four characters 181 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 182 ** 183 ** See also: [sqlite_version()] and [sqlite_source_id()]. 184 */ 185 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 186 SQLITE_API const char *sqlite3_libversion(void); 187 SQLITE_API const char *sqlite3_sourceid(void); 188 SQLITE_API int sqlite3_libversion_number(void); 189 190 /* 191 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 192 ** 193 ** ^The sqlite3_compileoption_used() function returns 0 or 1 194 ** indicating whether the specified option was defined at 195 ** compile time. ^The SQLITE_ prefix may be omitted from the 196 ** option name passed to sqlite3_compileoption_used(). 197 ** 198 ** ^The sqlite3_compileoption_get() function allows iterating 199 ** over the list of options that were defined at compile time by 200 ** returning the N-th compile time option string. ^If N is out of range, 201 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 202 ** prefix is omitted from any strings returned by 203 ** sqlite3_compileoption_get(). 204 ** 205 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 206 ** and sqlite3_compileoption_get() may be omitted by specifying the 207 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 208 ** 209 ** See also: SQL functions [sqlite_compileoption_used()] and 210 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 211 */ 212 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 213 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 214 SQLITE_API const char *sqlite3_compileoption_get(int N); 215 #else 216 # define sqlite3_compileoption_used(X) 0 217 # define sqlite3_compileoption_get(X) ((void*)0) 218 #endif 219 220 /* 221 ** CAPI3REF: Test To See If The Library Is Threadsafe 222 ** 223 ** ^The sqlite3_threadsafe() function returns zero if and only if 224 ** SQLite was compiled with mutexing code omitted due to the 225 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 226 ** 227 ** SQLite can be compiled with or without mutexes. When 228 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 229 ** are enabled and SQLite is threadsafe. When the 230 ** [SQLITE_THREADSAFE] macro is 0, 231 ** the mutexes are omitted. Without the mutexes, it is not safe 232 ** to use SQLite concurrently from more than one thread. 233 ** 234 ** Enabling mutexes incurs a measurable performance penalty. 235 ** So if speed is of utmost importance, it makes sense to disable 236 ** the mutexes. But for maximum safety, mutexes should be enabled. 237 ** ^The default behavior is for mutexes to be enabled. 238 ** 239 ** This interface can be used by an application to make sure that the 240 ** version of SQLite that it is linking against was compiled with 241 ** the desired setting of the [SQLITE_THREADSAFE] macro. 242 ** 243 ** This interface only reports on the compile-time mutex setting 244 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 245 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 246 ** can be fully or partially disabled using a call to [sqlite3_config()] 247 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 248 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 249 ** sqlite3_threadsafe() function shows only the compile-time setting of 250 ** thread safety, not any run-time changes to that setting made by 251 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 252 ** is unchanged by calls to sqlite3_config().)^ 253 ** 254 ** See the [threading mode] documentation for additional information. 255 */ 256 SQLITE_API int sqlite3_threadsafe(void); 257 258 /* 259 ** CAPI3REF: Database Connection Handle 260 ** KEYWORDS: {database connection} {database connections} 261 ** 262 ** Each open SQLite database is represented by a pointer to an instance of 263 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 264 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 265 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 266 ** and [sqlite3_close_v2()] are its destructors. There are many other 267 ** interfaces (such as 268 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 269 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 270 ** sqlite3 object. 271 */ 272 typedef struct sqlite3 sqlite3; 273 274 /* 275 ** CAPI3REF: 64-Bit Integer Types 276 ** KEYWORDS: sqlite_int64 sqlite_uint64 277 ** 278 ** Because there is no cross-platform way to specify 64-bit integer types 279 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 280 ** 281 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 282 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 283 ** compatibility only. 284 ** 285 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 286 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 287 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 288 ** between 0 and +18446744073709551615 inclusive. 289 */ 290 #ifdef SQLITE_INT64_TYPE 291 typedef SQLITE_INT64_TYPE sqlite_int64; 292 # ifdef SQLITE_UINT64_TYPE 293 typedef SQLITE_UINT64_TYPE sqlite_uint64; 294 # else 295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 296 # endif 297 #elif defined(_MSC_VER) || defined(__BORLANDC__) 298 typedef __int64 sqlite_int64; 299 typedef unsigned __int64 sqlite_uint64; 300 #else 301 typedef long long int sqlite_int64; 302 typedef unsigned long long int sqlite_uint64; 303 #endif 304 typedef sqlite_int64 sqlite3_int64; 305 typedef sqlite_uint64 sqlite3_uint64; 306 307 /* 308 ** If compiling for a processor that lacks floating point support, 309 ** substitute integer for floating-point. 310 */ 311 #ifdef SQLITE_OMIT_FLOATING_POINT 312 # define double sqlite3_int64 313 #endif 314 315 /* 316 ** CAPI3REF: Closing A Database Connection 317 ** DESTRUCTOR: sqlite3 318 ** 319 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 320 ** for the [sqlite3] object. 321 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 322 ** the [sqlite3] object is successfully destroyed and all associated 323 ** resources are deallocated. 324 ** 325 ** Ideally, applications should [sqlite3_finalize | finalize] all 326 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 327 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 328 ** with the [sqlite3] object prior to attempting to close the object. 329 ** ^If the database connection is associated with unfinalized prepared 330 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 331 ** sqlite3_close() will leave the database connection open and return 332 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 333 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 334 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 335 ** connection immediately, it marks the database connection as an unusable 336 ** "zombie" and makes arrangements to automatically deallocate the database 337 ** connection after all prepared statements are finalized, all BLOB handles 338 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 339 ** is intended for use with host languages that are garbage collected, and 340 ** where the order in which destructors are called is arbitrary. 341 ** 342 ** ^If an [sqlite3] object is destroyed while a transaction is open, 343 ** the transaction is automatically rolled back. 344 ** 345 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 346 ** must be either a NULL 347 ** pointer or an [sqlite3] object pointer obtained 348 ** from [sqlite3_open()], [sqlite3_open16()], or 349 ** [sqlite3_open_v2()], and not previously closed. 350 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 351 ** argument is a harmless no-op. 352 */ 353 SQLITE_API int sqlite3_close(sqlite3*); 354 SQLITE_API int sqlite3_close_v2(sqlite3*); 355 356 /* 357 ** The type for a callback function. 358 ** This is legacy and deprecated. It is included for historical 359 ** compatibility and is not documented. 360 */ 361 typedef int (*sqlite3_callback)(void*,int,char**, char**); 362 363 /* 364 ** CAPI3REF: One-Step Query Execution Interface 365 ** METHOD: sqlite3 366 ** 367 ** The sqlite3_exec() interface is a convenience wrapper around 368 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 369 ** that allows an application to run multiple statements of SQL 370 ** without having to use a lot of C code. 371 ** 372 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 373 ** semicolon-separate SQL statements passed into its 2nd argument, 374 ** in the context of the [database connection] passed in as its 1st 375 ** argument. ^If the callback function of the 3rd argument to 376 ** sqlite3_exec() is not NULL, then it is invoked for each result row 377 ** coming out of the evaluated SQL statements. ^The 4th argument to 378 ** sqlite3_exec() is relayed through to the 1st argument of each 379 ** callback invocation. ^If the callback pointer to sqlite3_exec() 380 ** is NULL, then no callback is ever invoked and result rows are 381 ** ignored. 382 ** 383 ** ^If an error occurs while evaluating the SQL statements passed into 384 ** sqlite3_exec(), then execution of the current statement stops and 385 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 386 ** is not NULL then any error message is written into memory obtained 387 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 388 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 389 ** on error message strings returned through the 5th parameter of 390 ** sqlite3_exec() after the error message string is no longer needed. 391 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 392 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 393 ** NULL before returning. 394 ** 395 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 396 ** routine returns SQLITE_ABORT without invoking the callback again and 397 ** without running any subsequent SQL statements. 398 ** 399 ** ^The 2nd argument to the sqlite3_exec() callback function is the 400 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 401 ** callback is an array of pointers to strings obtained as if from 402 ** [sqlite3_column_text()], one for each column. ^If an element of a 403 ** result row is NULL then the corresponding string pointer for the 404 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 405 ** sqlite3_exec() callback is an array of pointers to strings where each 406 ** entry represents the name of corresponding result column as obtained 407 ** from [sqlite3_column_name()]. 408 ** 409 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 410 ** to an empty string, or a pointer that contains only whitespace and/or 411 ** SQL comments, then no SQL statements are evaluated and the database 412 ** is not changed. 413 ** 414 ** Restrictions: 415 ** 416 ** <ul> 417 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 418 ** is a valid and open [database connection]. 419 ** <li> The application must not close the [database connection] specified by 420 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 421 ** <li> The application must not modify the SQL statement text passed into 422 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 423 ** </ul> 424 */ 425 SQLITE_API int sqlite3_exec( 426 sqlite3*, /* An open database */ 427 const char *sql, /* SQL to be evaluated */ 428 int (*callback)(void*,int,char**,char**), /* Callback function */ 429 void *, /* 1st argument to callback */ 430 char **errmsg /* Error msg written here */ 431 ); 432 433 /* 434 ** CAPI3REF: Result Codes 435 ** KEYWORDS: {result code definitions} 436 ** 437 ** Many SQLite functions return an integer result code from the set shown 438 ** here in order to indicate success or failure. 439 ** 440 ** New error codes may be added in future versions of SQLite. 441 ** 442 ** See also: [extended result code definitions] 443 */ 444 #define SQLITE_OK 0 /* Successful result */ 445 /* beginning-of-error-codes */ 446 #define SQLITE_ERROR 1 /* Generic error */ 447 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 448 #define SQLITE_PERM 3 /* Access permission denied */ 449 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 450 #define SQLITE_BUSY 5 /* The database file is locked */ 451 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 452 #define SQLITE_NOMEM 7 /* A malloc() failed */ 453 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 454 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 455 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 456 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 457 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 458 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 459 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 460 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 461 #define SQLITE_EMPTY 16 /* Internal use only */ 462 #define SQLITE_SCHEMA 17 /* The database schema changed */ 463 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 464 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 465 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 466 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 467 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 468 #define SQLITE_AUTH 23 /* Authorization denied */ 469 #define SQLITE_FORMAT 24 /* Not used */ 470 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 471 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 472 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 473 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 474 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 475 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 476 /* end-of-error-codes */ 477 478 /* 479 ** CAPI3REF: Extended Result Codes 480 ** KEYWORDS: {extended result code definitions} 481 ** 482 ** In its default configuration, SQLite API routines return one of 30 integer 483 ** [result codes]. However, experience has shown that many of 484 ** these result codes are too coarse-grained. They do not provide as 485 ** much information about problems as programmers might like. In an effort to 486 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 487 ** and later) include 488 ** support for additional result codes that provide more detailed information 489 ** about errors. These [extended result codes] are enabled or disabled 490 ** on a per database connection basis using the 491 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 492 ** the most recent error can be obtained using 493 ** [sqlite3_extended_errcode()]. 494 */ 495 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 496 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 497 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 498 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 499 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 500 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 501 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 502 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 503 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 504 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 505 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 506 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 507 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 508 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 509 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 510 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 511 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 512 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 513 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 514 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 515 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 516 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 517 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 518 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 519 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 520 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 521 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 522 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 523 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 524 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 525 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 526 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 527 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 528 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 529 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 530 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 531 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 532 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 533 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 534 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 535 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 536 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 537 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 538 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 539 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 540 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 541 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 542 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 543 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 544 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 545 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 546 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 547 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 548 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 549 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 550 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 551 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 552 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 553 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 554 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 555 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 556 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 557 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 558 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 559 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 560 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 561 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 562 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 563 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 564 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 565 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 566 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 567 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 568 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 569 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 570 571 /* 572 ** CAPI3REF: Flags For File Open Operations 573 ** 574 ** These bit values are intended for use in the 575 ** 3rd parameter to the [sqlite3_open_v2()] interface and 576 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 577 ** 578 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be 579 ** used as the third argument to the [sqlite3_open_v2()] interface. 580 ** The other flags have historically been ignored by sqlite3_open_v2(), 581 ** though future versions of SQLite might change so that an error is 582 ** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 583 ** Applications should not depend on the historical behavior. 584 ** 585 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 586 ** [sqlite3_open_v2()] does *not* cause the underlying database file 587 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 588 ** [sqlite3_open_v2()] has historically be a no-op and might become an 589 ** error in future versions of SQLite. 590 */ 591 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 592 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 593 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 594 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 595 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 596 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 597 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 598 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 599 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 600 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 601 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 602 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 603 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 604 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 605 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 606 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 607 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 608 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 609 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 610 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 611 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 612 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 613 614 /* Reserved: 0x00F00000 */ 615 /* Legacy compatibility: */ 616 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 617 618 619 /* 620 ** CAPI3REF: Device Characteristics 621 ** 622 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 623 ** object returns an integer which is a vector of these 624 ** bit values expressing I/O characteristics of the mass storage 625 ** device that holds the file that the [sqlite3_io_methods] 626 ** refers to. 627 ** 628 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 629 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 630 ** mean that writes of blocks that are nnn bytes in size and 631 ** are aligned to an address which is an integer multiple of 632 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 633 ** that when data is appended to a file, the data is appended 634 ** first then the size of the file is extended, never the other 635 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 636 ** information is written to disk in the same order as calls 637 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 638 ** after reboot following a crash or power loss, the only bytes in a 639 ** file that were written at the application level might have changed 640 ** and that adjacent bytes, even bytes within the same sector are 641 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 642 ** flag indicates that a file cannot be deleted when open. The 643 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 644 ** read-only media and cannot be changed even by processes with 645 ** elevated privileges. 646 ** 647 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 648 ** filesystem supports doing multiple write operations atomically when those 649 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 650 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 651 */ 652 #define SQLITE_IOCAP_ATOMIC 0x00000001 653 #define SQLITE_IOCAP_ATOMIC512 0x00000002 654 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 655 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 656 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 657 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 658 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 659 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 660 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 661 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 662 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 663 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 664 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 665 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 666 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 667 668 /* 669 ** CAPI3REF: File Locking Levels 670 ** 671 ** SQLite uses one of these integer values as the second 672 ** argument to calls it makes to the xLock() and xUnlock() methods 673 ** of an [sqlite3_io_methods] object. These values are ordered from 674 ** lest restrictive to most restrictive. 675 ** 676 ** The argument to xLock() is always SHARED or higher. The argument to 677 ** xUnlock is either SHARED or NONE. 678 */ 679 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */ 680 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ 681 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */ 682 #define SQLITE_LOCK_PENDING 3 /* xLock() only */ 683 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ 684 685 /* 686 ** CAPI3REF: Synchronization Type Flags 687 ** 688 ** When SQLite invokes the xSync() method of an 689 ** [sqlite3_io_methods] object it uses a combination of 690 ** these integer values as the second argument. 691 ** 692 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 693 ** sync operation only needs to flush data to mass storage. Inode 694 ** information need not be flushed. If the lower four bits of the flag 695 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 696 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 697 ** to use Mac OS X style fullsync instead of fsync(). 698 ** 699 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 700 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 701 ** settings. The [synchronous pragma] determines when calls to the 702 ** xSync VFS method occur and applies uniformly across all platforms. 703 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 704 ** energetic or rigorous or forceful the sync operations are and 705 ** only make a difference on Mac OSX for the default SQLite code. 706 ** (Third-party VFS implementations might also make the distinction 707 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 708 ** operating systems natively supported by SQLite, only Mac OSX 709 ** cares about the difference.) 710 */ 711 #define SQLITE_SYNC_NORMAL 0x00002 712 #define SQLITE_SYNC_FULL 0x00003 713 #define SQLITE_SYNC_DATAONLY 0x00010 714 715 /* 716 ** CAPI3REF: OS Interface Open File Handle 717 ** 718 ** An [sqlite3_file] object represents an open file in the 719 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 720 ** implementations will 721 ** want to subclass this object by appending additional fields 722 ** for their own use. The pMethods entry is a pointer to an 723 ** [sqlite3_io_methods] object that defines methods for performing 724 ** I/O operations on the open file. 725 */ 726 typedef struct sqlite3_file sqlite3_file; 727 struct sqlite3_file { 728 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 729 }; 730 731 /* 732 ** CAPI3REF: OS Interface File Virtual Methods Object 733 ** 734 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 735 ** [sqlite3_file] object (or, more commonly, a subclass of the 736 ** [sqlite3_file] object) with a pointer to an instance of this object. 737 ** This object defines the methods used to perform various operations 738 ** against the open file represented by the [sqlite3_file] object. 739 ** 740 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 741 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 742 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 743 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 744 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 745 ** to NULL. 746 ** 747 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 748 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 749 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 750 ** flag may be ORed in to indicate that only the data of the file 751 ** and not its inode needs to be synced. 752 ** 753 ** The integer values to xLock() and xUnlock() are one of 754 ** <ul> 755 ** <li> [SQLITE_LOCK_NONE], 756 ** <li> [SQLITE_LOCK_SHARED], 757 ** <li> [SQLITE_LOCK_RESERVED], 758 ** <li> [SQLITE_LOCK_PENDING], or 759 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 760 ** </ul> 761 ** xLock() upgrades the database file lock. In other words, xLock() moves the 762 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to 763 ** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never 764 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the 765 ** requested lock, then the call to xLock() is a no-op. 766 ** xUnlock() downgrades the database file lock to either SHARED or NONE. 767 * If the lock is already at or below the requested lock state, then the call 768 ** to xUnlock() is a no-op. 769 ** The xCheckReservedLock() method checks whether any database connection, 770 ** either in this process or in some other process, is holding a RESERVED, 771 ** PENDING, or EXCLUSIVE lock on the file. It returns true 772 ** if such a lock exists and false otherwise. 773 ** 774 ** The xFileControl() method is a generic interface that allows custom 775 ** VFS implementations to directly control an open file using the 776 ** [sqlite3_file_control()] interface. The second "op" argument is an 777 ** integer opcode. The third argument is a generic pointer intended to 778 ** point to a structure that may contain arguments or space in which to 779 ** write return values. Potential uses for xFileControl() might be 780 ** functions to enable blocking locks with timeouts, to change the 781 ** locking strategy (for example to use dot-file locks), to inquire 782 ** about the status of a lock, or to break stale locks. The SQLite 783 ** core reserves all opcodes less than 100 for its own use. 784 ** A [file control opcodes | list of opcodes] less than 100 is available. 785 ** Applications that define a custom xFileControl method should use opcodes 786 ** greater than 100 to avoid conflicts. VFS implementations should 787 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 788 ** recognize. 789 ** 790 ** The xSectorSize() method returns the sector size of the 791 ** device that underlies the file. The sector size is the 792 ** minimum write that can be performed without disturbing 793 ** other bytes in the file. The xDeviceCharacteristics() 794 ** method returns a bit vector describing behaviors of the 795 ** underlying device: 796 ** 797 ** <ul> 798 ** <li> [SQLITE_IOCAP_ATOMIC] 799 ** <li> [SQLITE_IOCAP_ATOMIC512] 800 ** <li> [SQLITE_IOCAP_ATOMIC1K] 801 ** <li> [SQLITE_IOCAP_ATOMIC2K] 802 ** <li> [SQLITE_IOCAP_ATOMIC4K] 803 ** <li> [SQLITE_IOCAP_ATOMIC8K] 804 ** <li> [SQLITE_IOCAP_ATOMIC16K] 805 ** <li> [SQLITE_IOCAP_ATOMIC32K] 806 ** <li> [SQLITE_IOCAP_ATOMIC64K] 807 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 808 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 809 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 810 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 811 ** <li> [SQLITE_IOCAP_IMMUTABLE] 812 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 813 ** </ul> 814 ** 815 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 816 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 817 ** mean that writes of blocks that are nnn bytes in size and 818 ** are aligned to an address which is an integer multiple of 819 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 820 ** that when data is appended to a file, the data is appended 821 ** first then the size of the file is extended, never the other 822 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 823 ** information is written to disk in the same order as calls 824 ** to xWrite(). 825 ** 826 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 827 ** in the unread portions of the buffer with zeros. A VFS that 828 ** fails to zero-fill short reads might seem to work. However, 829 ** failure to zero-fill short reads will eventually lead to 830 ** database corruption. 831 */ 832 typedef struct sqlite3_io_methods sqlite3_io_methods; 833 struct sqlite3_io_methods { 834 int iVersion; 835 int (*xClose)(sqlite3_file*); 836 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 837 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 838 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 839 int (*xSync)(sqlite3_file*, int flags); 840 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 841 int (*xLock)(sqlite3_file*, int); 842 int (*xUnlock)(sqlite3_file*, int); 843 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 844 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 845 int (*xSectorSize)(sqlite3_file*); 846 int (*xDeviceCharacteristics)(sqlite3_file*); 847 /* Methods above are valid for version 1 */ 848 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 849 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 850 void (*xShmBarrier)(sqlite3_file*); 851 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 852 /* Methods above are valid for version 2 */ 853 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 854 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 855 /* Methods above are valid for version 3 */ 856 /* Additional methods may be added in future releases */ 857 }; 858 859 /* 860 ** CAPI3REF: Standard File Control Opcodes 861 ** KEYWORDS: {file control opcodes} {file control opcode} 862 ** 863 ** These integer constants are opcodes for the xFileControl method 864 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 865 ** interface. 866 ** 867 ** <ul> 868 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 869 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 870 ** opcode causes the xFileControl method to write the current state of 871 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 872 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 873 ** into an integer that the pArg argument points to. 874 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. 875 ** 876 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 877 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 878 ** layer a hint of how large the database file will grow to be during the 879 ** current transaction. This hint is not guaranteed to be accurate but it 880 ** is often close. The underlying VFS might choose to preallocate database 881 ** file space based on this hint in order to help writes to the database 882 ** file run faster. 883 ** 884 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 885 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 886 ** implements [sqlite3_deserialize()] to set an upper bound on the size 887 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 888 ** If the integer pointed to is negative, then it is filled in with the 889 ** current limit. Otherwise the limit is set to the larger of the value 890 ** of the integer pointed to and the current database size. The integer 891 ** pointed to is set to the new limit. 892 ** 893 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 894 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 895 ** extends and truncates the database file in chunks of a size specified 896 ** by the user. The fourth argument to [sqlite3_file_control()] should 897 ** point to an integer (type int) containing the new chunk-size to use 898 ** for the nominated database. Allocating database file space in large 899 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 900 ** improve performance on some systems. 901 ** 902 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 903 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 904 ** to the [sqlite3_file] object associated with a particular database 905 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 906 ** 907 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 908 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 909 ** to the [sqlite3_file] object associated with the journal file (either 910 ** the [rollback journal] or the [write-ahead log]) for a particular database 911 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 912 ** 913 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 914 ** No longer in use. 915 ** 916 ** <li>[[SQLITE_FCNTL_SYNC]] 917 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 918 ** sent to the VFS immediately before the xSync method is invoked on a 919 ** database file descriptor. Or, if the xSync method is not invoked 920 ** because the user has configured SQLite with 921 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 922 ** of the xSync method. In most cases, the pointer argument passed with 923 ** this file-control is NULL. However, if the database file is being synced 924 ** as part of a multi-database commit, the argument points to a nul-terminated 925 ** string containing the transactions super-journal file name. VFSes that 926 ** do not need this signal should silently ignore this opcode. Applications 927 ** should not call [sqlite3_file_control()] with this opcode as doing so may 928 ** disrupt the operation of the specialized VFSes that do require it. 929 ** 930 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 931 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 932 ** and sent to the VFS after a transaction has been committed immediately 933 ** but before the database is unlocked. VFSes that do not need this signal 934 ** should silently ignore this opcode. Applications should not call 935 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 936 ** operation of the specialized VFSes that do require it. 937 ** 938 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 939 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 940 ** retry counts and intervals for certain disk I/O operations for the 941 ** windows [VFS] in order to provide robustness in the presence of 942 ** anti-virus programs. By default, the windows VFS will retry file read, 943 ** file write, and file delete operations up to 10 times, with a delay 944 ** of 25 milliseconds before the first retry and with the delay increasing 945 ** by an additional 25 milliseconds with each subsequent retry. This 946 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 947 ** to be adjusted. The values are changed for all database connections 948 ** within the same process. The argument is a pointer to an array of two 949 ** integers where the first integer is the new retry count and the second 950 ** integer is the delay. If either integer is negative, then the setting 951 ** is not changed but instead the prior value of that setting is written 952 ** into the array entry, allowing the current retry settings to be 953 ** interrogated. The zDbName parameter is ignored. 954 ** 955 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 956 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 957 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 958 ** write ahead log ([WAL file]) and shared memory 959 ** files used for transaction control 960 ** are automatically deleted when the latest connection to the database 961 ** closes. Setting persistent WAL mode causes those files to persist after 962 ** close. Persisting the files is useful when other processes that do not 963 ** have write permission on the directory containing the database file want 964 ** to read the database file, as the WAL and shared memory files must exist 965 ** in order for the database to be readable. The fourth parameter to 966 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 967 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 968 ** WAL mode. If the integer is -1, then it is overwritten with the current 969 ** WAL persistence setting. 970 ** 971 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 972 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 973 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 974 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 975 ** xDeviceCharacteristics methods. The fourth parameter to 976 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 977 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 978 ** mode. If the integer is -1, then it is overwritten with the current 979 ** zero-damage mode setting. 980 ** 981 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 982 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 983 ** a write transaction to indicate that, unless it is rolled back for some 984 ** reason, the entire database file will be overwritten by the current 985 ** transaction. This is used by VACUUM operations. 986 ** 987 ** <li>[[SQLITE_FCNTL_VFSNAME]] 988 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 989 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 990 ** final bottom-level VFS are written into memory obtained from 991 ** [sqlite3_malloc()] and the result is stored in the char* variable 992 ** that the fourth parameter of [sqlite3_file_control()] points to. 993 ** The caller is responsible for freeing the memory when done. As with 994 ** all file-control actions, there is no guarantee that this will actually 995 ** do anything. Callers should initialize the char* variable to a NULL 996 ** pointer in case this file-control is not implemented. This file-control 997 ** is intended for diagnostic use only. 998 ** 999 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 1000 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 1001 ** [VFSes] currently in use. ^(The argument X in 1002 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 1003 ** of type "[sqlite3_vfs] **". This opcodes will set *X 1004 ** to a pointer to the top-level VFS.)^ 1005 ** ^When there are multiple VFS shims in the stack, this opcode finds the 1006 ** upper-most shim only. 1007 ** 1008 ** <li>[[SQLITE_FCNTL_PRAGMA]] 1009 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1010 ** file control is sent to the open [sqlite3_file] object corresponding 1011 ** to the database file to which the pragma statement refers. ^The argument 1012 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1013 ** pointers to strings (char**) in which the second element of the array 1014 ** is the name of the pragma and the third element is the argument to the 1015 ** pragma or NULL if the pragma has no argument. ^The handler for an 1016 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1017 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1018 ** or the equivalent and that string will become the result of the pragma or 1019 ** the error message if the pragma fails. ^If the 1020 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1021 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1022 ** file control returns [SQLITE_OK], then the parser assumes that the 1023 ** VFS has handled the PRAGMA itself and the parser generates a no-op 1024 ** prepared statement if result string is NULL, or that returns a copy 1025 ** of the result string if the string is non-NULL. 1026 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1027 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1028 ** that the VFS encountered an error while handling the [PRAGMA] and the 1029 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1030 ** file control occurs at the beginning of pragma statement analysis and so 1031 ** it is able to override built-in [PRAGMA] statements. 1032 ** 1033 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1034 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 1035 ** file-control may be invoked by SQLite on the database file handle 1036 ** shortly after it is opened in order to provide a custom VFS with access 1037 ** to the connection's busy-handler callback. The argument is of type (void**) 1038 ** - an array of two (void *) values. The first (void *) actually points 1039 ** to a function of type (int (*)(void *)). In order to invoke the connection's 1040 ** busy-handler, this function should be invoked with the second (void *) in 1041 ** the array as the only argument. If it returns non-zero, then the operation 1042 ** should be retried. If it returns zero, the custom VFS should abandon the 1043 ** current operation. 1044 ** 1045 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1046 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1047 ** to have SQLite generate a 1048 ** temporary filename using the same algorithm that is followed to generate 1049 ** temporary filenames for TEMP tables and other internal uses. The 1050 ** argument should be a char** which will be filled with the filename 1051 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1052 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1053 ** 1054 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1055 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1056 ** maximum number of bytes that will be used for memory-mapped I/O. 1057 ** The argument is a pointer to a value of type sqlite3_int64 that 1058 ** is an advisory maximum number of bytes in the file to memory map. The 1059 ** pointer is overwritten with the old value. The limit is not changed if 1060 ** the value originally pointed to is negative, and so the current limit 1061 ** can be queried by passing in a pointer to a negative number. This 1062 ** file-control is used internally to implement [PRAGMA mmap_size]. 1063 ** 1064 ** <li>[[SQLITE_FCNTL_TRACE]] 1065 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1066 ** to the VFS about what the higher layers of the SQLite stack are doing. 1067 ** This file control is used by some VFS activity tracing [shims]. 1068 ** The argument is a zero-terminated string. Higher layers in the 1069 ** SQLite stack may generate instances of this file control if 1070 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1071 ** 1072 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1073 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1074 ** pointer to an integer and it writes a boolean into that integer depending 1075 ** on whether or not the file has been renamed, moved, or deleted since it 1076 ** was first opened. 1077 ** 1078 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1079 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1080 ** underlying native file handle associated with a file handle. This file 1081 ** control interprets its argument as a pointer to a native file handle and 1082 ** writes the resulting value there. 1083 ** 1084 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1085 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1086 ** opcode causes the xFileControl method to swap the file handle with the one 1087 ** pointed to by the pArg argument. This capability is used during testing 1088 ** and only needs to be supported when SQLITE_TEST is defined. 1089 ** 1090 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1091 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1092 ** be advantageous to block on the next WAL lock if the lock is not immediately 1093 ** available. The WAL subsystem issues this signal during rare 1094 ** circumstances in order to fix a problem with priority inversion. 1095 ** Applications should <em>not</em> use this file-control. 1096 ** 1097 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1098 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1099 ** VFS should return SQLITE_NOTFOUND for this opcode. 1100 ** 1101 ** <li>[[SQLITE_FCNTL_RBU]] 1102 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1103 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1104 ** this opcode. 1105 ** 1106 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1107 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1108 ** the file descriptor is placed in "batch write mode", which 1109 ** means all subsequent write operations will be deferred and done 1110 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1111 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1112 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1113 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1114 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1115 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1116 ** except for calls to the xWrite method and the xFileControl method 1117 ** with [SQLITE_FCNTL_SIZE_HINT]. 1118 ** 1119 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1120 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1121 ** operations since the previous successful call to 1122 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1123 ** This file control returns [SQLITE_OK] if and only if the writes were 1124 ** all performed successfully and have been committed to persistent storage. 1125 ** ^Regardless of whether or not it is successful, this file control takes 1126 ** the file descriptor out of batch write mode so that all subsequent 1127 ** write operations are independent. 1128 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1129 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1130 ** 1131 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1132 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1133 ** operations since the previous successful call to 1134 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1135 ** ^This file control takes the file descriptor out of batch write mode 1136 ** so that all subsequent write operations are independent. 1137 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1138 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1139 ** 1140 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1141 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1142 ** to block for up to M milliseconds before failing when attempting to 1143 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1144 ** The parameter is a pointer to a 32-bit signed integer that contains 1145 ** the value that M is to be set to. Before returning, the 32-bit signed 1146 ** integer is overwritten with the previous value of M. 1147 ** 1148 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1149 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1150 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1151 ** The "data version" for the pager is written into the pointer. The 1152 ** "data version" changes whenever any change occurs to the corresponding 1153 ** database file, either through SQL statements on the same database 1154 ** connection or through transactions committed by separate database 1155 ** connections possibly in other processes. The [sqlite3_total_changes()] 1156 ** interface can be used to find if any database on the connection has changed, 1157 ** but that interface responds to changes on TEMP as well as MAIN and does 1158 ** not provide a mechanism to detect changes to MAIN only. Also, the 1159 ** [sqlite3_total_changes()] interface responds to internal changes only and 1160 ** omits changes made by other database connections. The 1161 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1162 ** a single attached database that occur due to other database connections, 1163 ** but omits changes implemented by the database connection on which it is 1164 ** called. This file control is the only mechanism to detect changes that 1165 ** happen either internally or externally and that are associated with 1166 ** a particular attached database. 1167 ** 1168 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1169 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1170 ** in wal mode before the client starts to copy pages from the wal 1171 ** file to the database file. 1172 ** 1173 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1174 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1175 ** in wal mode after the client has finished copying pages from the wal 1176 ** file to the database file, but before the *-shm file is updated to 1177 ** record the fact that the pages have been checkpointed. 1178 ** </ul> 1179 ** 1180 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1181 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1182 ** whether or not there is a database client in another process with a wal-mode 1183 ** transaction open on the database or not. It is only available on unix.The 1184 ** (void*) argument passed with this file-control should be a pointer to a 1185 ** value of type (int). The integer value is set to 1 if the database is a wal 1186 ** mode database and there exists at least one client in another process that 1187 ** currently has an SQL transaction open on the database. It is set to 0 if 1188 ** the database is not a wal-mode db, or if there is no such connection in any 1189 ** other process. This opcode cannot be used to detect transactions opened 1190 ** by clients within the current process, only within other processes. 1191 ** </ul> 1192 ** 1193 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1194 ** Used by the cksmvfs VFS module only. 1195 ** </ul> 1196 */ 1197 #define SQLITE_FCNTL_LOCKSTATE 1 1198 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1199 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1200 #define SQLITE_FCNTL_LAST_ERRNO 4 1201 #define SQLITE_FCNTL_SIZE_HINT 5 1202 #define SQLITE_FCNTL_CHUNK_SIZE 6 1203 #define SQLITE_FCNTL_FILE_POINTER 7 1204 #define SQLITE_FCNTL_SYNC_OMITTED 8 1205 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1206 #define SQLITE_FCNTL_PERSIST_WAL 10 1207 #define SQLITE_FCNTL_OVERWRITE 11 1208 #define SQLITE_FCNTL_VFSNAME 12 1209 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1210 #define SQLITE_FCNTL_PRAGMA 14 1211 #define SQLITE_FCNTL_BUSYHANDLER 15 1212 #define SQLITE_FCNTL_TEMPFILENAME 16 1213 #define SQLITE_FCNTL_MMAP_SIZE 18 1214 #define SQLITE_FCNTL_TRACE 19 1215 #define SQLITE_FCNTL_HAS_MOVED 20 1216 #define SQLITE_FCNTL_SYNC 21 1217 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1218 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1219 #define SQLITE_FCNTL_WAL_BLOCK 24 1220 #define SQLITE_FCNTL_ZIPVFS 25 1221 #define SQLITE_FCNTL_RBU 26 1222 #define SQLITE_FCNTL_VFS_POINTER 27 1223 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1224 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1225 #define SQLITE_FCNTL_PDB 30 1226 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1227 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1228 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1229 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1230 #define SQLITE_FCNTL_DATA_VERSION 35 1231 #define SQLITE_FCNTL_SIZE_LIMIT 36 1232 #define SQLITE_FCNTL_CKPT_DONE 37 1233 #define SQLITE_FCNTL_RESERVE_BYTES 38 1234 #define SQLITE_FCNTL_CKPT_START 39 1235 #define SQLITE_FCNTL_EXTERNAL_READER 40 1236 #define SQLITE_FCNTL_CKSM_FILE 41 1237 1238 /* deprecated names */ 1239 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1240 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1241 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1242 1243 1244 /* 1245 ** CAPI3REF: Mutex Handle 1246 ** 1247 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1248 ** abstract type for a mutex object. The SQLite core never looks 1249 ** at the internal representation of an [sqlite3_mutex]. It only 1250 ** deals with pointers to the [sqlite3_mutex] object. 1251 ** 1252 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1253 */ 1254 typedef struct sqlite3_mutex sqlite3_mutex; 1255 1256 /* 1257 ** CAPI3REF: Loadable Extension Thunk 1258 ** 1259 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1260 ** the third parameter to entry points of [loadable extensions]. This 1261 ** structure must be typedefed in order to work around compiler warnings 1262 ** on some platforms. 1263 */ 1264 typedef struct sqlite3_api_routines sqlite3_api_routines; 1265 1266 /* 1267 ** CAPI3REF: File Name 1268 ** 1269 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the 1270 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated 1271 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but 1272 ** may also be passed to special APIs such as: 1273 ** 1274 ** <ul> 1275 ** <li> sqlite3_filename_database() 1276 ** <li> sqlite3_filename_journal() 1277 ** <li> sqlite3_filename_wal() 1278 ** <li> sqlite3_uri_parameter() 1279 ** <li> sqlite3_uri_boolean() 1280 ** <li> sqlite3_uri_int64() 1281 ** <li> sqlite3_uri_key() 1282 ** </ul> 1283 */ 1284 typedef const char *sqlite3_filename; 1285 1286 /* 1287 ** CAPI3REF: OS Interface Object 1288 ** 1289 ** An instance of the sqlite3_vfs object defines the interface between 1290 ** the SQLite core and the underlying operating system. The "vfs" 1291 ** in the name of the object stands for "virtual file system". See 1292 ** the [VFS | VFS documentation] for further information. 1293 ** 1294 ** The VFS interface is sometimes extended by adding new methods onto 1295 ** the end. Each time such an extension occurs, the iVersion field 1296 ** is incremented. The iVersion value started out as 1 in 1297 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1298 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1299 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1300 ** may be appended to the sqlite3_vfs object and the iVersion value 1301 ** may increase again in future versions of SQLite. 1302 ** Note that due to an oversight, the structure 1303 ** of the sqlite3_vfs object changed in the transition from 1304 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1305 ** and yet the iVersion field was not increased. 1306 ** 1307 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1308 ** structure used by this VFS. mxPathname is the maximum length of 1309 ** a pathname in this VFS. 1310 ** 1311 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1312 ** the pNext pointer. The [sqlite3_vfs_register()] 1313 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1314 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1315 ** searches the list. Neither the application code nor the VFS 1316 ** implementation should use the pNext pointer. 1317 ** 1318 ** The pNext field is the only field in the sqlite3_vfs 1319 ** structure that SQLite will ever modify. SQLite will only access 1320 ** or modify this field while holding a particular static mutex. 1321 ** The application should never modify anything within the sqlite3_vfs 1322 ** object once the object has been registered. 1323 ** 1324 ** The zName field holds the name of the VFS module. The name must 1325 ** be unique across all VFS modules. 1326 ** 1327 ** [[sqlite3_vfs.xOpen]] 1328 ** ^SQLite guarantees that the zFilename parameter to xOpen 1329 ** is either a NULL pointer or string obtained 1330 ** from xFullPathname() with an optional suffix added. 1331 ** ^If a suffix is added to the zFilename parameter, it will 1332 ** consist of a single "-" character followed by no more than 1333 ** 11 alphanumeric and/or "-" characters. 1334 ** ^SQLite further guarantees that 1335 ** the string will be valid and unchanged until xClose() is 1336 ** called. Because of the previous sentence, 1337 ** the [sqlite3_file] can safely store a pointer to the 1338 ** filename if it needs to remember the filename for some reason. 1339 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1340 ** must invent its own temporary name for the file. ^Whenever the 1341 ** xFilename parameter is NULL it will also be the case that the 1342 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1343 ** 1344 ** The flags argument to xOpen() includes all bits set in 1345 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1346 ** or [sqlite3_open16()] is used, then flags includes at least 1347 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1348 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1349 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1350 ** 1351 ** ^(SQLite will also add one of the following flags to the xOpen() 1352 ** call, depending on the object being opened: 1353 ** 1354 ** <ul> 1355 ** <li> [SQLITE_OPEN_MAIN_DB] 1356 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1357 ** <li> [SQLITE_OPEN_TEMP_DB] 1358 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1359 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1360 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1361 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1362 ** <li> [SQLITE_OPEN_WAL] 1363 ** </ul>)^ 1364 ** 1365 ** The file I/O implementation can use the object type flags to 1366 ** change the way it deals with files. For example, an application 1367 ** that does not care about crash recovery or rollback might make 1368 ** the open of a journal file a no-op. Writes to this journal would 1369 ** also be no-ops, and any attempt to read the journal would return 1370 ** SQLITE_IOERR. Or the implementation might recognize that a database 1371 ** file will be doing page-aligned sector reads and writes in a random 1372 ** order and set up its I/O subsystem accordingly. 1373 ** 1374 ** SQLite might also add one of the following flags to the xOpen method: 1375 ** 1376 ** <ul> 1377 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1378 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1379 ** </ul> 1380 ** 1381 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1382 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1383 ** will be set for TEMP databases and their journals, transient 1384 ** databases, and subjournals. 1385 ** 1386 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1387 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1388 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1389 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1390 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1391 ** be created, and that it is an error if it already exists. 1392 ** It is <i>not</i> used to indicate the file should be opened 1393 ** for exclusive access. 1394 ** 1395 ** ^At least szOsFile bytes of memory are allocated by SQLite 1396 ** to hold the [sqlite3_file] structure passed as the third 1397 ** argument to xOpen. The xOpen method does not have to 1398 ** allocate the structure; it should just fill it in. Note that 1399 ** the xOpen method must set the sqlite3_file.pMethods to either 1400 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1401 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1402 ** element will be valid after xOpen returns regardless of the success 1403 ** or failure of the xOpen call. 1404 ** 1405 ** [[sqlite3_vfs.xAccess]] 1406 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1407 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1408 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1409 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1410 ** flag is never actually used and is not implemented in the built-in 1411 ** VFSes of SQLite. The file is named by the second argument and can be a 1412 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1413 ** non-zero error code if there is an I/O error or if the name of 1414 ** the file given in the second argument is illegal. If SQLITE_OK 1415 ** is returned, then non-zero or zero is written into *pResOut to indicate 1416 ** whether or not the file is accessible. 1417 ** 1418 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1419 ** output buffer xFullPathname. The exact size of the output buffer 1420 ** is also passed as a parameter to both methods. If the output buffer 1421 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1422 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1423 ** to prevent this by setting mxPathname to a sufficiently large value. 1424 ** 1425 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1426 ** interfaces are not strictly a part of the filesystem, but they are 1427 ** included in the VFS structure for completeness. 1428 ** The xRandomness() function attempts to return nBytes bytes 1429 ** of good-quality randomness into zOut. The return value is 1430 ** the actual number of bytes of randomness obtained. 1431 ** The xSleep() method causes the calling thread to sleep for at 1432 ** least the number of microseconds given. ^The xCurrentTime() 1433 ** method returns a Julian Day Number for the current date and time as 1434 ** a floating point value. 1435 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1436 ** Day Number multiplied by 86400000 (the number of milliseconds in 1437 ** a 24-hour day). 1438 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1439 ** date and time if that method is available (if iVersion is 2 or 1440 ** greater and the function pointer is not NULL) and will fall back 1441 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1442 ** 1443 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1444 ** are not used by the SQLite core. These optional interfaces are provided 1445 ** by some VFSes to facilitate testing of the VFS code. By overriding 1446 ** system calls with functions under its control, a test program can 1447 ** simulate faults and error conditions that would otherwise be difficult 1448 ** or impossible to induce. The set of system calls that can be overridden 1449 ** varies from one VFS to another, and from one version of the same VFS to the 1450 ** next. Applications that use these interfaces must be prepared for any 1451 ** or all of these interfaces to be NULL or for their behavior to change 1452 ** from one release to the next. Applications must not attempt to access 1453 ** any of these methods if the iVersion of the VFS is less than 3. 1454 */ 1455 typedef struct sqlite3_vfs sqlite3_vfs; 1456 typedef void (*sqlite3_syscall_ptr)(void); 1457 struct sqlite3_vfs { 1458 int iVersion; /* Structure version number (currently 3) */ 1459 int szOsFile; /* Size of subclassed sqlite3_file */ 1460 int mxPathname; /* Maximum file pathname length */ 1461 sqlite3_vfs *pNext; /* Next registered VFS */ 1462 const char *zName; /* Name of this virtual file system */ 1463 void *pAppData; /* Pointer to application-specific data */ 1464 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, 1465 int flags, int *pOutFlags); 1466 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1467 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1468 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1469 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1470 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1471 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1472 void (*xDlClose)(sqlite3_vfs*, void*); 1473 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1474 int (*xSleep)(sqlite3_vfs*, int microseconds); 1475 int (*xCurrentTime)(sqlite3_vfs*, double*); 1476 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1477 /* 1478 ** The methods above are in version 1 of the sqlite_vfs object 1479 ** definition. Those that follow are added in version 2 or later 1480 */ 1481 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1482 /* 1483 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1484 ** Those below are for version 3 and greater. 1485 */ 1486 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1487 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1488 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1489 /* 1490 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1491 ** New fields may be appended in future versions. The iVersion 1492 ** value will increment whenever this happens. 1493 */ 1494 }; 1495 1496 /* 1497 ** CAPI3REF: Flags for the xAccess VFS method 1498 ** 1499 ** These integer constants can be used as the third parameter to 1500 ** the xAccess method of an [sqlite3_vfs] object. They determine 1501 ** what kind of permissions the xAccess method is looking for. 1502 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1503 ** simply checks whether the file exists. 1504 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1505 ** checks whether the named directory is both readable and writable 1506 ** (in other words, if files can be added, removed, and renamed within 1507 ** the directory). 1508 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1509 ** [temp_store_directory pragma], though this could change in a future 1510 ** release of SQLite. 1511 ** With SQLITE_ACCESS_READ, the xAccess method 1512 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1513 ** currently unused, though it might be used in a future release of 1514 ** SQLite. 1515 */ 1516 #define SQLITE_ACCESS_EXISTS 0 1517 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1518 #define SQLITE_ACCESS_READ 2 /* Unused */ 1519 1520 /* 1521 ** CAPI3REF: Flags for the xShmLock VFS method 1522 ** 1523 ** These integer constants define the various locking operations 1524 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1525 ** following are the only legal combinations of flags to the 1526 ** xShmLock method: 1527 ** 1528 ** <ul> 1529 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1530 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1531 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1532 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1533 ** </ul> 1534 ** 1535 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1536 ** was given on the corresponding lock. 1537 ** 1538 ** The xShmLock method can transition between unlocked and SHARED or 1539 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1540 ** and EXCLUSIVE. 1541 */ 1542 #define SQLITE_SHM_UNLOCK 1 1543 #define SQLITE_SHM_LOCK 2 1544 #define SQLITE_SHM_SHARED 4 1545 #define SQLITE_SHM_EXCLUSIVE 8 1546 1547 /* 1548 ** CAPI3REF: Maximum xShmLock index 1549 ** 1550 ** The xShmLock method on [sqlite3_io_methods] may use values 1551 ** between 0 and this upper bound as its "offset" argument. 1552 ** The SQLite core will never attempt to acquire or release a 1553 ** lock outside of this range 1554 */ 1555 #define SQLITE_SHM_NLOCK 8 1556 1557 1558 /* 1559 ** CAPI3REF: Initialize The SQLite Library 1560 ** 1561 ** ^The sqlite3_initialize() routine initializes the 1562 ** SQLite library. ^The sqlite3_shutdown() routine 1563 ** deallocates any resources that were allocated by sqlite3_initialize(). 1564 ** These routines are designed to aid in process initialization and 1565 ** shutdown on embedded systems. Workstation applications using 1566 ** SQLite normally do not need to invoke either of these routines. 1567 ** 1568 ** A call to sqlite3_initialize() is an "effective" call if it is 1569 ** the first time sqlite3_initialize() is invoked during the lifetime of 1570 ** the process, or if it is the first time sqlite3_initialize() is invoked 1571 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1572 ** of sqlite3_initialize() does any initialization. All other calls 1573 ** are harmless no-ops.)^ 1574 ** 1575 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1576 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1577 ** an effective call to sqlite3_shutdown() does any deinitialization. 1578 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1579 ** 1580 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1581 ** is not. The sqlite3_shutdown() interface must only be called from a 1582 ** single thread. All open [database connections] must be closed and all 1583 ** other SQLite resources must be deallocated prior to invoking 1584 ** sqlite3_shutdown(). 1585 ** 1586 ** Among other things, ^sqlite3_initialize() will invoke 1587 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1588 ** will invoke sqlite3_os_end(). 1589 ** 1590 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1591 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1592 ** the library (perhaps it is unable to allocate a needed resource such 1593 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1594 ** 1595 ** ^The sqlite3_initialize() routine is called internally by many other 1596 ** SQLite interfaces so that an application usually does not need to 1597 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1598 ** calls sqlite3_initialize() so the SQLite library will be automatically 1599 ** initialized when [sqlite3_open()] is called if it has not be initialized 1600 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1601 ** compile-time option, then the automatic calls to sqlite3_initialize() 1602 ** are omitted and the application must call sqlite3_initialize() directly 1603 ** prior to using any other SQLite interface. For maximum portability, 1604 ** it is recommended that applications always invoke sqlite3_initialize() 1605 ** directly prior to using any other SQLite interface. Future releases 1606 ** of SQLite may require this. In other words, the behavior exhibited 1607 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1608 ** default behavior in some future release of SQLite. 1609 ** 1610 ** The sqlite3_os_init() routine does operating-system specific 1611 ** initialization of the SQLite library. The sqlite3_os_end() 1612 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1613 ** performed by these routines include allocation or deallocation 1614 ** of static resources, initialization of global variables, 1615 ** setting up a default [sqlite3_vfs] module, or setting up 1616 ** a default configuration using [sqlite3_config()]. 1617 ** 1618 ** The application should never invoke either sqlite3_os_init() 1619 ** or sqlite3_os_end() directly. The application should only invoke 1620 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1621 ** interface is called automatically by sqlite3_initialize() and 1622 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1623 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1624 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1625 ** When [custom builds | built for other platforms] 1626 ** (using the [SQLITE_OS_OTHER=1] compile-time 1627 ** option) the application must supply a suitable implementation for 1628 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1629 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1630 ** must return [SQLITE_OK] on success and some other [error code] upon 1631 ** failure. 1632 */ 1633 SQLITE_API int sqlite3_initialize(void); 1634 SQLITE_API int sqlite3_shutdown(void); 1635 SQLITE_API int sqlite3_os_init(void); 1636 SQLITE_API int sqlite3_os_end(void); 1637 1638 /* 1639 ** CAPI3REF: Configuring The SQLite Library 1640 ** 1641 ** The sqlite3_config() interface is used to make global configuration 1642 ** changes to SQLite in order to tune SQLite to the specific needs of 1643 ** the application. The default configuration is recommended for most 1644 ** applications and so this routine is usually not necessary. It is 1645 ** provided to support rare applications with unusual needs. 1646 ** 1647 ** <b>The sqlite3_config() interface is not threadsafe. The application 1648 ** must ensure that no other SQLite interfaces are invoked by other 1649 ** threads while sqlite3_config() is running.</b> 1650 ** 1651 ** The sqlite3_config() interface 1652 ** may only be invoked prior to library initialization using 1653 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1654 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1655 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1656 ** Note, however, that ^sqlite3_config() can be called as part of the 1657 ** implementation of an application-defined [sqlite3_os_init()]. 1658 ** 1659 ** The first argument to sqlite3_config() is an integer 1660 ** [configuration option] that determines 1661 ** what property of SQLite is to be configured. Subsequent arguments 1662 ** vary depending on the [configuration option] 1663 ** in the first argument. 1664 ** 1665 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1666 ** ^If the option is unknown or SQLite is unable to set the option 1667 ** then this routine returns a non-zero [error code]. 1668 */ 1669 SQLITE_API int sqlite3_config(int, ...); 1670 1671 /* 1672 ** CAPI3REF: Configure database connections 1673 ** METHOD: sqlite3 1674 ** 1675 ** The sqlite3_db_config() interface is used to make configuration 1676 ** changes to a [database connection]. The interface is similar to 1677 ** [sqlite3_config()] except that the changes apply to a single 1678 ** [database connection] (specified in the first argument). 1679 ** 1680 ** The second argument to sqlite3_db_config(D,V,...) is the 1681 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1682 ** that indicates what aspect of the [database connection] is being configured. 1683 ** Subsequent arguments vary depending on the configuration verb. 1684 ** 1685 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1686 ** the call is considered successful. 1687 */ 1688 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1689 1690 /* 1691 ** CAPI3REF: Memory Allocation Routines 1692 ** 1693 ** An instance of this object defines the interface between SQLite 1694 ** and low-level memory allocation routines. 1695 ** 1696 ** This object is used in only one place in the SQLite interface. 1697 ** A pointer to an instance of this object is the argument to 1698 ** [sqlite3_config()] when the configuration option is 1699 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1700 ** By creating an instance of this object 1701 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1702 ** during configuration, an application can specify an alternative 1703 ** memory allocation subsystem for SQLite to use for all of its 1704 ** dynamic memory needs. 1705 ** 1706 ** Note that SQLite comes with several [built-in memory allocators] 1707 ** that are perfectly adequate for the overwhelming majority of applications 1708 ** and that this object is only useful to a tiny minority of applications 1709 ** with specialized memory allocation requirements. This object is 1710 ** also used during testing of SQLite in order to specify an alternative 1711 ** memory allocator that simulates memory out-of-memory conditions in 1712 ** order to verify that SQLite recovers gracefully from such 1713 ** conditions. 1714 ** 1715 ** The xMalloc, xRealloc, and xFree methods must work like the 1716 ** malloc(), realloc() and free() functions from the standard C library. 1717 ** ^SQLite guarantees that the second argument to 1718 ** xRealloc is always a value returned by a prior call to xRoundup. 1719 ** 1720 ** xSize should return the allocated size of a memory allocation 1721 ** previously obtained from xMalloc or xRealloc. The allocated size 1722 ** is always at least as big as the requested size but may be larger. 1723 ** 1724 ** The xRoundup method returns what would be the allocated size of 1725 ** a memory allocation given a particular requested size. Most memory 1726 ** allocators round up memory allocations at least to the next multiple 1727 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1728 ** Every memory allocation request coming in through [sqlite3_malloc()] 1729 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1730 ** that causes the corresponding memory allocation to fail. 1731 ** 1732 ** The xInit method initializes the memory allocator. For example, 1733 ** it might allocate any required mutexes or initialize internal data 1734 ** structures. The xShutdown method is invoked (indirectly) by 1735 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1736 ** by xInit. The pAppData pointer is used as the only parameter to 1737 ** xInit and xShutdown. 1738 ** 1739 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1740 ** the xInit method, so the xInit method need not be threadsafe. The 1741 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1742 ** not need to be threadsafe either. For all other methods, SQLite 1743 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1744 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1745 ** it is by default) and so the methods are automatically serialized. 1746 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1747 ** methods must be threadsafe or else make their own arrangements for 1748 ** serialization. 1749 ** 1750 ** SQLite will never invoke xInit() more than once without an intervening 1751 ** call to xShutdown(). 1752 */ 1753 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1754 struct sqlite3_mem_methods { 1755 void *(*xMalloc)(int); /* Memory allocation function */ 1756 void (*xFree)(void*); /* Free a prior allocation */ 1757 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1758 int (*xSize)(void*); /* Return the size of an allocation */ 1759 int (*xRoundup)(int); /* Round up request size to allocation size */ 1760 int (*xInit)(void*); /* Initialize the memory allocator */ 1761 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1762 void *pAppData; /* Argument to xInit() and xShutdown() */ 1763 }; 1764 1765 /* 1766 ** CAPI3REF: Configuration Options 1767 ** KEYWORDS: {configuration option} 1768 ** 1769 ** These constants are the available integer configuration options that 1770 ** can be passed as the first argument to the [sqlite3_config()] interface. 1771 ** 1772 ** New configuration options may be added in future releases of SQLite. 1773 ** Existing configuration options might be discontinued. Applications 1774 ** should check the return code from [sqlite3_config()] to make sure that 1775 ** the call worked. The [sqlite3_config()] interface will return a 1776 ** non-zero [error code] if a discontinued or unsupported configuration option 1777 ** is invoked. 1778 ** 1779 ** <dl> 1780 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1781 ** <dd>There are no arguments to this option. ^This option sets the 1782 ** [threading mode] to Single-thread. In other words, it disables 1783 ** all mutexing and puts SQLite into a mode where it can only be used 1784 ** by a single thread. ^If SQLite is compiled with 1785 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1786 ** it is not possible to change the [threading mode] from its default 1787 ** value of Single-thread and so [sqlite3_config()] will return 1788 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1789 ** configuration option.</dd> 1790 ** 1791 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1792 ** <dd>There are no arguments to this option. ^This option sets the 1793 ** [threading mode] to Multi-thread. In other words, it disables 1794 ** mutexing on [database connection] and [prepared statement] objects. 1795 ** The application is responsible for serializing access to 1796 ** [database connections] and [prepared statements]. But other mutexes 1797 ** are enabled so that SQLite will be safe to use in a multi-threaded 1798 ** environment as long as no two threads attempt to use the same 1799 ** [database connection] at the same time. ^If SQLite is compiled with 1800 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1801 ** it is not possible to set the Multi-thread [threading mode] and 1802 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1803 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1804 ** 1805 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1806 ** <dd>There are no arguments to this option. ^This option sets the 1807 ** [threading mode] to Serialized. In other words, this option enables 1808 ** all mutexes including the recursive 1809 ** mutexes on [database connection] and [prepared statement] objects. 1810 ** In this mode (which is the default when SQLite is compiled with 1811 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1812 ** to [database connections] and [prepared statements] so that the 1813 ** application is free to use the same [database connection] or the 1814 ** same [prepared statement] in different threads at the same time. 1815 ** ^If SQLite is compiled with 1816 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1817 ** it is not possible to set the Serialized [threading mode] and 1818 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1819 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1820 ** 1821 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1822 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1823 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1824 ** The argument specifies 1825 ** alternative low-level memory allocation routines to be used in place of 1826 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1827 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1828 ** before the [sqlite3_config()] call returns.</dd> 1829 ** 1830 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1831 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1832 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1833 ** The [sqlite3_mem_methods] 1834 ** structure is filled with the currently defined memory allocation routines.)^ 1835 ** This option can be used to overload the default memory allocation 1836 ** routines with a wrapper that simulations memory allocation failure or 1837 ** tracks memory usage, for example. </dd> 1838 ** 1839 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1840 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1841 ** type int, interpreted as a boolean, which if true provides a hint to 1842 ** SQLite that it should avoid large memory allocations if possible. 1843 ** SQLite will run faster if it is free to make large memory allocations, 1844 ** but some application might prefer to run slower in exchange for 1845 ** guarantees about memory fragmentation that are possible if large 1846 ** allocations are avoided. This hint is normally off. 1847 ** </dd> 1848 ** 1849 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1850 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1851 ** interpreted as a boolean, which enables or disables the collection of 1852 ** memory allocation statistics. ^(When memory allocation statistics are 1853 ** disabled, the following SQLite interfaces become non-operational: 1854 ** <ul> 1855 ** <li> [sqlite3_hard_heap_limit64()] 1856 ** <li> [sqlite3_memory_used()] 1857 ** <li> [sqlite3_memory_highwater()] 1858 ** <li> [sqlite3_soft_heap_limit64()] 1859 ** <li> [sqlite3_status64()] 1860 ** </ul>)^ 1861 ** ^Memory allocation statistics are enabled by default unless SQLite is 1862 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1863 ** allocation statistics are disabled by default. 1864 ** </dd> 1865 ** 1866 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1867 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1868 ** </dd> 1869 ** 1870 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1871 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1872 ** that SQLite can use for the database page cache with the default page 1873 ** cache implementation. 1874 ** This configuration option is a no-op if an application-defined page 1875 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1876 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1877 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1878 ** and the number of cache lines (N). 1879 ** The sz argument should be the size of the largest database page 1880 ** (a power of two between 512 and 65536) plus some extra bytes for each 1881 ** page header. ^The number of extra bytes needed by the page header 1882 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1883 ** ^It is harmless, apart from the wasted memory, 1884 ** for the sz parameter to be larger than necessary. The pMem 1885 ** argument must be either a NULL pointer or a pointer to an 8-byte 1886 ** aligned block of memory of at least sz*N bytes, otherwise 1887 ** subsequent behavior is undefined. 1888 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1889 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1890 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1891 ** is exhausted. 1892 ** ^If pMem is NULL and N is non-zero, then each database connection 1893 ** does an initial bulk allocation for page cache memory 1894 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1895 ** of -1024*N bytes if N is negative, . ^If additional 1896 ** page cache memory is needed beyond what is provided by the initial 1897 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1898 ** additional cache line. </dd> 1899 ** 1900 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1901 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1902 ** that SQLite will use for all of its dynamic memory allocation needs 1903 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1904 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1905 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1906 ** [SQLITE_ERROR] if invoked otherwise. 1907 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1908 ** An 8-byte aligned pointer to the memory, 1909 ** the number of bytes in the memory buffer, and the minimum allocation size. 1910 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1911 ** to using its default memory allocator (the system malloc() implementation), 1912 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1913 ** memory pointer is not NULL then the alternative memory 1914 ** allocator is engaged to handle all of SQLites memory allocation needs. 1915 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1916 ** boundary or subsequent behavior of SQLite will be undefined. 1917 ** The minimum allocation size is capped at 2**12. Reasonable values 1918 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1919 ** 1920 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1921 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1922 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1923 ** The argument specifies alternative low-level mutex routines to be used 1924 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1925 ** the content of the [sqlite3_mutex_methods] structure before the call to 1926 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1927 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1928 ** the entire mutexing subsystem is omitted from the build and hence calls to 1929 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1930 ** return [SQLITE_ERROR].</dd> 1931 ** 1932 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1933 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1934 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1935 ** [sqlite3_mutex_methods] 1936 ** structure is filled with the currently defined mutex routines.)^ 1937 ** This option can be used to overload the default mutex allocation 1938 ** routines with a wrapper used to track mutex usage for performance 1939 ** profiling or testing, for example. ^If SQLite is compiled with 1940 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1941 ** the entire mutexing subsystem is omitted from the build and hence calls to 1942 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1943 ** return [SQLITE_ERROR].</dd> 1944 ** 1945 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1946 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1947 ** the default size of lookaside memory on each [database connection]. 1948 ** The first argument is the 1949 ** size of each lookaside buffer slot and the second is the number of 1950 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1951 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1952 ** option to [sqlite3_db_config()] can be used to change the lookaside 1953 ** configuration on individual connections.)^ </dd> 1954 ** 1955 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1956 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1957 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1958 ** the interface to a custom page cache implementation.)^ 1959 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1960 ** 1961 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1962 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1963 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1964 ** the current page cache implementation into that object.)^ </dd> 1965 ** 1966 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1967 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1968 ** global [error log]. 1969 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1970 ** function with a call signature of void(*)(void*,int,const char*), 1971 ** and a pointer to void. ^If the function pointer is not NULL, it is 1972 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1973 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1974 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1975 ** passed through as the first parameter to the application-defined logger 1976 ** function whenever that function is invoked. ^The second parameter to 1977 ** the logger function is a copy of the first parameter to the corresponding 1978 ** [sqlite3_log()] call and is intended to be a [result code] or an 1979 ** [extended result code]. ^The third parameter passed to the logger is 1980 ** log message after formatting via [sqlite3_snprintf()]. 1981 ** The SQLite logging interface is not reentrant; the logger function 1982 ** supplied by the application must not invoke any SQLite interface. 1983 ** In a multi-threaded application, the application-defined logger 1984 ** function must be threadsafe. </dd> 1985 ** 1986 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1987 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1988 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1989 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1990 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1991 ** [sqlite3_open16()] or 1992 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1993 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1994 ** connection is opened. ^If it is globally disabled, filenames are 1995 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1996 ** database connection is opened. ^(By default, URI handling is globally 1997 ** disabled. The default value may be changed by compiling with the 1998 ** [SQLITE_USE_URI] symbol defined.)^ 1999 ** 2000 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 2001 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 2002 ** argument which is interpreted as a boolean in order to enable or disable 2003 ** the use of covering indices for full table scans in the query optimizer. 2004 ** ^The default setting is determined 2005 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 2006 ** if that compile-time option is omitted. 2007 ** The ability to disable the use of covering indices for full table scans 2008 ** is because some incorrectly coded legacy applications might malfunction 2009 ** when the optimization is enabled. Providing the ability to 2010 ** disable the optimization allows the older, buggy application code to work 2011 ** without change even with newer versions of SQLite. 2012 ** 2013 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 2014 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 2015 ** <dd> These options are obsolete and should not be used by new code. 2016 ** They are retained for backwards compatibility but are now no-ops. 2017 ** </dd> 2018 ** 2019 ** [[SQLITE_CONFIG_SQLLOG]] 2020 ** <dt>SQLITE_CONFIG_SQLLOG 2021 ** <dd>This option is only available if sqlite is compiled with the 2022 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 2023 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 2024 ** The second should be of type (void*). The callback is invoked by the library 2025 ** in three separate circumstances, identified by the value passed as the 2026 ** fourth parameter. If the fourth parameter is 0, then the database connection 2027 ** passed as the second argument has just been opened. The third argument 2028 ** points to a buffer containing the name of the main database file. If the 2029 ** fourth parameter is 1, then the SQL statement that the third parameter 2030 ** points to has just been executed. Or, if the fourth parameter is 2, then 2031 ** the connection being passed as the second parameter is being closed. The 2032 ** third parameter is passed NULL In this case. An example of using this 2033 ** configuration option can be seen in the "test_sqllog.c" source file in 2034 ** the canonical SQLite source tree.</dd> 2035 ** 2036 ** [[SQLITE_CONFIG_MMAP_SIZE]] 2037 ** <dt>SQLITE_CONFIG_MMAP_SIZE 2038 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2039 ** that are the default mmap size limit (the default setting for 2040 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2041 ** ^The default setting can be overridden by each database connection using 2042 ** either the [PRAGMA mmap_size] command, or by using the 2043 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2044 ** will be silently truncated if necessary so that it does not exceed the 2045 ** compile-time maximum mmap size set by the 2046 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2047 ** ^If either argument to this option is negative, then that argument is 2048 ** changed to its compile-time default. 2049 ** 2050 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2051 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2052 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2053 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2054 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2055 ** that specifies the maximum size of the created heap. 2056 ** 2057 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2058 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2059 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2060 ** is a pointer to an integer and writes into that integer the number of extra 2061 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2062 ** The amount of extra space required can change depending on the compiler, 2063 ** target platform, and SQLite version. 2064 ** 2065 ** [[SQLITE_CONFIG_PMASZ]] 2066 ** <dt>SQLITE_CONFIG_PMASZ 2067 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2068 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2069 ** sorter to that integer. The default minimum PMA Size is set by the 2070 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2071 ** to help with sort operations when multithreaded sorting 2072 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2073 ** to be sorted exceeds the page size times the minimum of the 2074 ** [PRAGMA cache_size] setting and this value. 2075 ** 2076 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2077 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2078 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2079 ** becomes the [statement journal] spill-to-disk threshold. 2080 ** [Statement journals] are held in memory until their size (in bytes) 2081 ** exceeds this threshold, at which point they are written to disk. 2082 ** Or if the threshold is -1, statement journals are always held 2083 ** exclusively in memory. 2084 ** Since many statement journals never become large, setting the spill 2085 ** threshold to a value such as 64KiB can greatly reduce the amount of 2086 ** I/O required to support statement rollback. 2087 ** The default value for this setting is controlled by the 2088 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2089 ** 2090 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2091 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2092 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2093 ** of type (int) - the new value of the sorter-reference size threshold. 2094 ** Usually, when SQLite uses an external sort to order records according 2095 ** to an ORDER BY clause, all fields required by the caller are present in the 2096 ** sorted records. However, if SQLite determines based on the declared type 2097 ** of a table column that its values are likely to be very large - larger 2098 ** than the configured sorter-reference size threshold - then a reference 2099 ** is stored in each sorted record and the required column values loaded 2100 ** from the database as records are returned in sorted order. The default 2101 ** value for this option is to never use this optimization. Specifying a 2102 ** negative value for this option restores the default behaviour. 2103 ** This option is only available if SQLite is compiled with the 2104 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2105 ** 2106 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2107 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2108 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2109 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2110 ** database created using [sqlite3_deserialize()]. This default maximum 2111 ** size can be adjusted up or down for individual databases using the 2112 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2113 ** configuration setting is never used, then the default maximum is determined 2114 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2115 ** compile-time option is not set, then the default maximum is 1073741824. 2116 ** </dl> 2117 */ 2118 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2119 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2120 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2121 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2122 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2123 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2124 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2125 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2126 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2127 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2128 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2129 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2130 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2131 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2132 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2133 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2134 #define SQLITE_CONFIG_URI 17 /* int */ 2135 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2136 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2137 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2138 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2139 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2140 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2141 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2142 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2143 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2144 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2145 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2146 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2147 2148 /* 2149 ** CAPI3REF: Database Connection Configuration Options 2150 ** 2151 ** These constants are the available integer configuration options that 2152 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2153 ** 2154 ** New configuration options may be added in future releases of SQLite. 2155 ** Existing configuration options might be discontinued. Applications 2156 ** should check the return code from [sqlite3_db_config()] to make sure that 2157 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2158 ** non-zero [error code] if a discontinued or unsupported configuration option 2159 ** is invoked. 2160 ** 2161 ** <dl> 2162 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2163 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2164 ** <dd> ^This option takes three additional arguments that determine the 2165 ** [lookaside memory allocator] configuration for the [database connection]. 2166 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2167 ** pointer to a memory buffer to use for lookaside memory. 2168 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2169 ** may be NULL in which case SQLite will allocate the 2170 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2171 ** size of each lookaside buffer slot. ^The third argument is the number of 2172 ** slots. The size of the buffer in the first argument must be greater than 2173 ** or equal to the product of the second and third arguments. The buffer 2174 ** must be aligned to an 8-byte boundary. ^If the second argument to 2175 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2176 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2177 ** configuration for a database connection can only be changed when that 2178 ** connection is not currently using lookaside memory, or in other words 2179 ** when the "current value" returned by 2180 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2181 ** Any attempt to change the lookaside memory configuration when lookaside 2182 ** memory is in use leaves the configuration unchanged and returns 2183 ** [SQLITE_BUSY].)^</dd> 2184 ** 2185 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2186 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2187 ** <dd> ^This option is used to enable or disable the enforcement of 2188 ** [foreign key constraints]. There should be two additional arguments. 2189 ** The first argument is an integer which is 0 to disable FK enforcement, 2190 ** positive to enable FK enforcement or negative to leave FK enforcement 2191 ** unchanged. The second parameter is a pointer to an integer into which 2192 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2193 ** following this call. The second parameter may be a NULL pointer, in 2194 ** which case the FK enforcement setting is not reported back. </dd> 2195 ** 2196 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2197 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2198 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2199 ** There should be two additional arguments. 2200 ** The first argument is an integer which is 0 to disable triggers, 2201 ** positive to enable triggers or negative to leave the setting unchanged. 2202 ** The second parameter is a pointer to an integer into which 2203 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2204 ** following this call. The second parameter may be a NULL pointer, in 2205 ** which case the trigger setting is not reported back. 2206 ** 2207 ** <p>Originally this option disabled all triggers. ^(However, since 2208 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2209 ** this option is off. So, in other words, this option now only disables 2210 ** triggers in the main database schema or in the schemas of ATTACH-ed 2211 ** databases.)^ </dd> 2212 ** 2213 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2214 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2215 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2216 ** There should be two additional arguments. 2217 ** The first argument is an integer which is 0 to disable views, 2218 ** positive to enable views or negative to leave the setting unchanged. 2219 ** The second parameter is a pointer to an integer into which 2220 ** is written 0 or 1 to indicate whether views are disabled or enabled 2221 ** following this call. The second parameter may be a NULL pointer, in 2222 ** which case the view setting is not reported back. 2223 ** 2224 ** <p>Originally this option disabled all views. ^(However, since 2225 ** SQLite version 3.35.0, TEMP views are still allowed even if 2226 ** this option is off. So, in other words, this option now only disables 2227 ** views in the main database schema or in the schemas of ATTACH-ed 2228 ** databases.)^ </dd> 2229 ** 2230 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2231 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2232 ** <dd> ^This option is used to enable or disable the 2233 ** [fts3_tokenizer()] function which is part of the 2234 ** [FTS3] full-text search engine extension. 2235 ** There should be two additional arguments. 2236 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2237 ** positive to enable fts3_tokenizer() or negative to leave the setting 2238 ** unchanged. 2239 ** The second parameter is a pointer to an integer into which 2240 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2241 ** following this call. The second parameter may be a NULL pointer, in 2242 ** which case the new setting is not reported back. </dd> 2243 ** 2244 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2245 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2246 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2247 ** interface independently of the [load_extension()] SQL function. 2248 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2249 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2250 ** There should be two additional arguments. 2251 ** When the first argument to this interface is 1, then only the C-API is 2252 ** enabled and the SQL function remains disabled. If the first argument to 2253 ** this interface is 0, then both the C-API and the SQL function are disabled. 2254 ** If the first argument is -1, then no changes are made to state of either the 2255 ** C-API or the SQL function. 2256 ** The second parameter is a pointer to an integer into which 2257 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2258 ** is disabled or enabled following this call. The second parameter may 2259 ** be a NULL pointer, in which case the new setting is not reported back. 2260 ** </dd> 2261 ** 2262 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2263 ** <dd> ^This option is used to change the name of the "main" database 2264 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2265 ** which will become the new schema name in place of "main". ^SQLite 2266 ** does not make a copy of the new main schema name string, so the application 2267 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2268 ** until after the database connection closes. 2269 ** </dd> 2270 ** 2271 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2272 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2273 ** <dd> Usually, when a database in wal mode is closed or detached from a 2274 ** database handle, SQLite checks if this will mean that there are now no 2275 ** connections at all to the database. If so, it performs a checkpoint 2276 ** operation before closing the connection. This option may be used to 2277 ** override this behaviour. The first parameter passed to this operation 2278 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2279 ** default) to enable them, and negative to leave the setting unchanged. 2280 ** The second parameter is a pointer to an integer 2281 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2282 ** have been disabled - 0 if they are not disabled, 1 if they are. 2283 ** </dd> 2284 ** 2285 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2286 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2287 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2288 ** a single SQL query statement will always use the same algorithm regardless 2289 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2290 ** that look at the values of bound parameters, which can make some queries 2291 ** slower. But the QPSG has the advantage of more predictable behavior. With 2292 ** the QPSG active, SQLite will always use the same query plan in the field as 2293 ** was used during testing in the lab. 2294 ** The first argument to this setting is an integer which is 0 to disable 2295 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2296 ** unchanged. The second parameter is a pointer to an integer into which 2297 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2298 ** following this call. 2299 ** </dd> 2300 ** 2301 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2302 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2303 ** include output for any operations performed by trigger programs. This 2304 ** option is used to set or clear (the default) a flag that governs this 2305 ** behavior. The first parameter passed to this operation is an integer - 2306 ** positive to enable output for trigger programs, or zero to disable it, 2307 ** or negative to leave the setting unchanged. 2308 ** The second parameter is a pointer to an integer into which is written 2309 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2310 ** it is not disabled, 1 if it is. 2311 ** </dd> 2312 ** 2313 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2314 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2315 ** [VACUUM] in order to reset a database back to an empty database 2316 ** with no schema and no content. The following process works even for 2317 ** a badly corrupted database file: 2318 ** <ol> 2319 ** <li> If the database connection is newly opened, make sure it has read the 2320 ** database schema by preparing then discarding some query against the 2321 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2322 ** errors. This step is only necessary if the application desires to keep 2323 ** the database in WAL mode after the reset if it was in WAL mode before 2324 ** the reset. 2325 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2326 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2327 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2328 ** </ol> 2329 ** Because resetting a database is destructive and irreversible, the 2330 ** process requires the use of this obscure API and multiple steps to help 2331 ** ensure that it does not happen by accident. 2332 ** 2333 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2334 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2335 ** "defensive" flag for a database connection. When the defensive 2336 ** flag is enabled, language features that allow ordinary SQL to 2337 ** deliberately corrupt the database file are disabled. The disabled 2338 ** features include but are not limited to the following: 2339 ** <ul> 2340 ** <li> The [PRAGMA writable_schema=ON] statement. 2341 ** <li> The [PRAGMA journal_mode=OFF] statement. 2342 ** <li> The [PRAGMA schema_version=N] statement. 2343 ** <li> Writes to the [sqlite_dbpage] virtual table. 2344 ** <li> Direct writes to [shadow tables]. 2345 ** </ul> 2346 ** </dd> 2347 ** 2348 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2349 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2350 ** "writable_schema" flag. This has the same effect and is logically equivalent 2351 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2352 ** The first argument to this setting is an integer which is 0 to disable 2353 ** the writable_schema, positive to enable writable_schema, or negative to 2354 ** leave the setting unchanged. The second parameter is a pointer to an 2355 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2356 ** is enabled or disabled following this call. 2357 ** </dd> 2358 ** 2359 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2360 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2361 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2362 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2363 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2364 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2365 ** additional information. This feature can also be turned on and off 2366 ** using the [PRAGMA legacy_alter_table] statement. 2367 ** </dd> 2368 ** 2369 ** [[SQLITE_DBCONFIG_DQS_DML]] 2370 ** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2371 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2372 ** the legacy [double-quoted string literal] misfeature for DML statements 2373 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2374 ** default value of this setting is determined by the [-DSQLITE_DQS] 2375 ** compile-time option. 2376 ** </dd> 2377 ** 2378 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2379 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2380 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2381 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2382 ** such as CREATE TABLE and CREATE INDEX. The 2383 ** default value of this setting is determined by the [-DSQLITE_DQS] 2384 ** compile-time option. 2385 ** </dd> 2386 ** 2387 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2388 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2389 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2390 ** assume that database schemas are untainted by malicious content. 2391 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2392 ** takes additional defensive steps to protect the application from harm 2393 ** including: 2394 ** <ul> 2395 ** <li> Prohibit the use of SQL functions inside triggers, views, 2396 ** CHECK constraints, DEFAULT clauses, expression indexes, 2397 ** partial indexes, or generated columns 2398 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2399 ** <li> Prohibit the use of virtual tables inside of triggers or views 2400 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2401 ** </ul> 2402 ** This setting defaults to "on" for legacy compatibility, however 2403 ** all applications are advised to turn it off if possible. This setting 2404 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2405 ** </dd> 2406 ** 2407 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2408 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2409 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2410 ** the legacy file format flag. When activated, this flag causes all newly 2411 ** created database file to have a schema format version number (the 4-byte 2412 ** integer found at offset 44 into the database header) of 1. This in turn 2413 ** means that the resulting database file will be readable and writable by 2414 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2415 ** newly created databases are generally not understandable by SQLite versions 2416 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2417 ** is now scarcely any need to generated database files that are compatible 2418 ** all the way back to version 3.0.0, and so this setting is of little 2419 ** practical use, but is provided so that SQLite can continue to claim the 2420 ** ability to generate new database files that are compatible with version 2421 ** 3.0.0. 2422 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2423 ** the [VACUUM] command will fail with an obscure error when attempting to 2424 ** process a table with generated columns and a descending index. This is 2425 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2426 ** either generated columns or decending indexes. 2427 ** </dd> 2428 ** </dl> 2429 */ 2430 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2431 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2432 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2433 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2434 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2435 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2436 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2437 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2438 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2439 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2440 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2441 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2442 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2443 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2444 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2445 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2446 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2447 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2448 #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2449 2450 /* 2451 ** CAPI3REF: Enable Or Disable Extended Result Codes 2452 ** METHOD: sqlite3 2453 ** 2454 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2455 ** [extended result codes] feature of SQLite. ^The extended result 2456 ** codes are disabled by default for historical compatibility. 2457 */ 2458 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2459 2460 /* 2461 ** CAPI3REF: Last Insert Rowid 2462 ** METHOD: sqlite3 2463 ** 2464 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2465 ** has a unique 64-bit signed 2466 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2467 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2468 ** names are not also used by explicitly declared columns. ^If 2469 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2470 ** is another alias for the rowid. 2471 ** 2472 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2473 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2474 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2475 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2476 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2477 ** zero. 2478 ** 2479 ** As well as being set automatically as rows are inserted into database 2480 ** tables, the value returned by this function may be set explicitly by 2481 ** [sqlite3_set_last_insert_rowid()] 2482 ** 2483 ** Some virtual table implementations may INSERT rows into rowid tables as 2484 ** part of committing a transaction (e.g. to flush data accumulated in memory 2485 ** to disk). In this case subsequent calls to this function return the rowid 2486 ** associated with these internal INSERT operations, which leads to 2487 ** unintuitive results. Virtual table implementations that do write to rowid 2488 ** tables in this way can avoid this problem by restoring the original 2489 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2490 ** control to the user. 2491 ** 2492 ** ^(If an [INSERT] occurs within a trigger then this routine will 2493 ** return the [rowid] of the inserted row as long as the trigger is 2494 ** running. Once the trigger program ends, the value returned 2495 ** by this routine reverts to what it was before the trigger was fired.)^ 2496 ** 2497 ** ^An [INSERT] that fails due to a constraint violation is not a 2498 ** successful [INSERT] and does not change the value returned by this 2499 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2500 ** and INSERT OR ABORT make no changes to the return value of this 2501 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2502 ** encounters a constraint violation, it does not fail. The 2503 ** INSERT continues to completion after deleting rows that caused 2504 ** the constraint problem so INSERT OR REPLACE will always change 2505 ** the return value of this interface.)^ 2506 ** 2507 ** ^For the purposes of this routine, an [INSERT] is considered to 2508 ** be successful even if it is subsequently rolled back. 2509 ** 2510 ** This function is accessible to SQL statements via the 2511 ** [last_insert_rowid() SQL function]. 2512 ** 2513 ** If a separate thread performs a new [INSERT] on the same 2514 ** database connection while the [sqlite3_last_insert_rowid()] 2515 ** function is running and thus changes the last insert [rowid], 2516 ** then the value returned by [sqlite3_last_insert_rowid()] is 2517 ** unpredictable and might not equal either the old or the new 2518 ** last insert [rowid]. 2519 */ 2520 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2521 2522 /* 2523 ** CAPI3REF: Set the Last Insert Rowid value. 2524 ** METHOD: sqlite3 2525 ** 2526 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2527 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2528 ** without inserting a row into the database. 2529 */ 2530 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2531 2532 /* 2533 ** CAPI3REF: Count The Number Of Rows Modified 2534 ** METHOD: sqlite3 2535 ** 2536 ** ^These functions return the number of rows modified, inserted or 2537 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2538 ** statement on the database connection specified by the only parameter. 2539 ** The two functions are identical except for the type of the return value 2540 ** and that if the number of rows modified by the most recent INSERT, UPDATE 2541 ** or DELETE is greater than the maximum value supported by type "int", then 2542 ** the return value of sqlite3_changes() is undefined. ^Executing any other 2543 ** type of SQL statement does not modify the value returned by these functions. 2544 ** 2545 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2546 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2547 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2548 ** 2549 ** Changes to a view that are intercepted by 2550 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2551 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2552 ** DELETE statement run on a view is always zero. Only changes made to real 2553 ** tables are counted. 2554 ** 2555 ** Things are more complicated if the sqlite3_changes() function is 2556 ** executed while a trigger program is running. This may happen if the 2557 ** program uses the [changes() SQL function], or if some other callback 2558 ** function invokes sqlite3_changes() directly. Essentially: 2559 ** 2560 ** <ul> 2561 ** <li> ^(Before entering a trigger program the value returned by 2562 ** sqlite3_changes() function is saved. After the trigger program 2563 ** has finished, the original value is restored.)^ 2564 ** 2565 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2566 ** statement sets the value returned by sqlite3_changes() 2567 ** upon completion as normal. Of course, this value will not include 2568 ** any changes performed by sub-triggers, as the sqlite3_changes() 2569 ** value will be saved and restored after each sub-trigger has run.)^ 2570 ** </ul> 2571 ** 2572 ** ^This means that if the changes() SQL function (or similar) is used 2573 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2574 ** returns the value as set when the calling statement began executing. 2575 ** ^If it is used by the second or subsequent such statement within a trigger 2576 ** program, the value returned reflects the number of rows modified by the 2577 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2578 ** 2579 ** If a separate thread makes changes on the same database connection 2580 ** while [sqlite3_changes()] is running then the value returned 2581 ** is unpredictable and not meaningful. 2582 ** 2583 ** See also: 2584 ** <ul> 2585 ** <li> the [sqlite3_total_changes()] interface 2586 ** <li> the [count_changes pragma] 2587 ** <li> the [changes() SQL function] 2588 ** <li> the [data_version pragma] 2589 ** </ul> 2590 */ 2591 SQLITE_API int sqlite3_changes(sqlite3*); 2592 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2593 2594 /* 2595 ** CAPI3REF: Total Number Of Rows Modified 2596 ** METHOD: sqlite3 2597 ** 2598 ** ^These functions return the total number of rows inserted, modified or 2599 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2600 ** since the database connection was opened, including those executed as 2601 ** part of trigger programs. The two functions are identical except for the 2602 ** type of the return value and that if the number of rows modified by the 2603 ** connection exceeds the maximum value supported by type "int", then 2604 ** the return value of sqlite3_total_changes() is undefined. ^Executing 2605 ** any other type of SQL statement does not affect the value returned by 2606 ** sqlite3_total_changes(). 2607 ** 2608 ** ^Changes made as part of [foreign key actions] are included in the 2609 ** count, but those made as part of REPLACE constraint resolution are 2610 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2611 ** are not counted. 2612 ** 2613 ** The [sqlite3_total_changes(D)] interface only reports the number 2614 ** of rows that changed due to SQL statement run against database 2615 ** connection D. Any changes by other database connections are ignored. 2616 ** To detect changes against a database file from other database 2617 ** connections use the [PRAGMA data_version] command or the 2618 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2619 ** 2620 ** If a separate thread makes changes on the same database connection 2621 ** while [sqlite3_total_changes()] is running then the value 2622 ** returned is unpredictable and not meaningful. 2623 ** 2624 ** See also: 2625 ** <ul> 2626 ** <li> the [sqlite3_changes()] interface 2627 ** <li> the [count_changes pragma] 2628 ** <li> the [changes() SQL function] 2629 ** <li> the [data_version pragma] 2630 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2631 ** </ul> 2632 */ 2633 SQLITE_API int sqlite3_total_changes(sqlite3*); 2634 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2635 2636 /* 2637 ** CAPI3REF: Interrupt A Long-Running Query 2638 ** METHOD: sqlite3 2639 ** 2640 ** ^This function causes any pending database operation to abort and 2641 ** return at its earliest opportunity. This routine is typically 2642 ** called in response to a user action such as pressing "Cancel" 2643 ** or Ctrl-C where the user wants a long query operation to halt 2644 ** immediately. 2645 ** 2646 ** ^It is safe to call this routine from a thread different from the 2647 ** thread that is currently running the database operation. But it 2648 ** is not safe to call this routine with a [database connection] that 2649 ** is closed or might close before sqlite3_interrupt() returns. 2650 ** 2651 ** ^If an SQL operation is very nearly finished at the time when 2652 ** sqlite3_interrupt() is called, then it might not have an opportunity 2653 ** to be interrupted and might continue to completion. 2654 ** 2655 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2656 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2657 ** that is inside an explicit transaction, then the entire transaction 2658 ** will be rolled back automatically. 2659 ** 2660 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2661 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2662 ** that are started after the sqlite3_interrupt() call and before the 2663 ** running statement count reaches zero are interrupted as if they had been 2664 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2665 ** that are started after the running statement count reaches zero are 2666 ** not effected by the sqlite3_interrupt(). 2667 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2668 ** SQL statements is a no-op and has no effect on SQL statements 2669 ** that are started after the sqlite3_interrupt() call returns. 2670 */ 2671 SQLITE_API void sqlite3_interrupt(sqlite3*); 2672 2673 /* 2674 ** CAPI3REF: Determine If An SQL Statement Is Complete 2675 ** 2676 ** These routines are useful during command-line input to determine if the 2677 ** currently entered text seems to form a complete SQL statement or 2678 ** if additional input is needed before sending the text into 2679 ** SQLite for parsing. ^These routines return 1 if the input string 2680 ** appears to be a complete SQL statement. ^A statement is judged to be 2681 ** complete if it ends with a semicolon token and is not a prefix of a 2682 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2683 ** string literals or quoted identifier names or comments are not 2684 ** independent tokens (they are part of the token in which they are 2685 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2686 ** and comments that follow the final semicolon are ignored. 2687 ** 2688 ** ^These routines return 0 if the statement is incomplete. ^If a 2689 ** memory allocation fails, then SQLITE_NOMEM is returned. 2690 ** 2691 ** ^These routines do not parse the SQL statements thus 2692 ** will not detect syntactically incorrect SQL. 2693 ** 2694 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2695 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2696 ** automatically by sqlite3_complete16(). If that initialization fails, 2697 ** then the return value from sqlite3_complete16() will be non-zero 2698 ** regardless of whether or not the input SQL is complete.)^ 2699 ** 2700 ** The input to [sqlite3_complete()] must be a zero-terminated 2701 ** UTF-8 string. 2702 ** 2703 ** The input to [sqlite3_complete16()] must be a zero-terminated 2704 ** UTF-16 string in native byte order. 2705 */ 2706 SQLITE_API int sqlite3_complete(const char *sql); 2707 SQLITE_API int sqlite3_complete16(const void *sql); 2708 2709 /* 2710 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2711 ** KEYWORDS: {busy-handler callback} {busy handler} 2712 ** METHOD: sqlite3 2713 ** 2714 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2715 ** that might be invoked with argument P whenever 2716 ** an attempt is made to access a database table associated with 2717 ** [database connection] D when another thread 2718 ** or process has the table locked. 2719 ** The sqlite3_busy_handler() interface is used to implement 2720 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2721 ** 2722 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2723 ** is returned immediately upon encountering the lock. ^If the busy callback 2724 ** is not NULL, then the callback might be invoked with two arguments. 2725 ** 2726 ** ^The first argument to the busy handler is a copy of the void* pointer which 2727 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2728 ** the busy handler callback is the number of times that the busy handler has 2729 ** been invoked previously for the same locking event. ^If the 2730 ** busy callback returns 0, then no additional attempts are made to 2731 ** access the database and [SQLITE_BUSY] is returned 2732 ** to the application. 2733 ** ^If the callback returns non-zero, then another attempt 2734 ** is made to access the database and the cycle repeats. 2735 ** 2736 ** The presence of a busy handler does not guarantee that it will be invoked 2737 ** when there is lock contention. ^If SQLite determines that invoking the busy 2738 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2739 ** to the application instead of invoking the 2740 ** busy handler. 2741 ** Consider a scenario where one process is holding a read lock that 2742 ** it is trying to promote to a reserved lock and 2743 ** a second process is holding a reserved lock that it is trying 2744 ** to promote to an exclusive lock. The first process cannot proceed 2745 ** because it is blocked by the second and the second process cannot 2746 ** proceed because it is blocked by the first. If both processes 2747 ** invoke the busy handlers, neither will make any progress. Therefore, 2748 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2749 ** will induce the first process to release its read lock and allow 2750 ** the second process to proceed. 2751 ** 2752 ** ^The default busy callback is NULL. 2753 ** 2754 ** ^(There can only be a single busy handler defined for each 2755 ** [database connection]. Setting a new busy handler clears any 2756 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2757 ** or evaluating [PRAGMA busy_timeout=N] will change the 2758 ** busy handler and thus clear any previously set busy handler. 2759 ** 2760 ** The busy callback should not take any actions which modify the 2761 ** database connection that invoked the busy handler. In other words, 2762 ** the busy handler is not reentrant. Any such actions 2763 ** result in undefined behavior. 2764 ** 2765 ** A busy handler must not close the database connection 2766 ** or [prepared statement] that invoked the busy handler. 2767 */ 2768 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2769 2770 /* 2771 ** CAPI3REF: Set A Busy Timeout 2772 ** METHOD: sqlite3 2773 ** 2774 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2775 ** for a specified amount of time when a table is locked. ^The handler 2776 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2777 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2778 ** the handler returns 0 which causes [sqlite3_step()] to return 2779 ** [SQLITE_BUSY]. 2780 ** 2781 ** ^Calling this routine with an argument less than or equal to zero 2782 ** turns off all busy handlers. 2783 ** 2784 ** ^(There can only be a single busy handler for a particular 2785 ** [database connection] at any given moment. If another busy handler 2786 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2787 ** this routine, that other busy handler is cleared.)^ 2788 ** 2789 ** See also: [PRAGMA busy_timeout] 2790 */ 2791 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2792 2793 /* 2794 ** CAPI3REF: Convenience Routines For Running Queries 2795 ** METHOD: sqlite3 2796 ** 2797 ** This is a legacy interface that is preserved for backwards compatibility. 2798 ** Use of this interface is not recommended. 2799 ** 2800 ** Definition: A <b>result table</b> is memory data structure created by the 2801 ** [sqlite3_get_table()] interface. A result table records the 2802 ** complete query results from one or more queries. 2803 ** 2804 ** The table conceptually has a number of rows and columns. But 2805 ** these numbers are not part of the result table itself. These 2806 ** numbers are obtained separately. Let N be the number of rows 2807 ** and M be the number of columns. 2808 ** 2809 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2810 ** There are (N+1)*M elements in the array. The first M pointers point 2811 ** to zero-terminated strings that contain the names of the columns. 2812 ** The remaining entries all point to query results. NULL values result 2813 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2814 ** string representation as returned by [sqlite3_column_text()]. 2815 ** 2816 ** A result table might consist of one or more memory allocations. 2817 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2818 ** A result table should be deallocated using [sqlite3_free_table()]. 2819 ** 2820 ** ^(As an example of the result table format, suppose a query result 2821 ** is as follows: 2822 ** 2823 ** <blockquote><pre> 2824 ** Name | Age 2825 ** ----------------------- 2826 ** Alice | 43 2827 ** Bob | 28 2828 ** Cindy | 21 2829 ** </pre></blockquote> 2830 ** 2831 ** There are two columns (M==2) and three rows (N==3). Thus the 2832 ** result table has 8 entries. Suppose the result table is stored 2833 ** in an array named azResult. Then azResult holds this content: 2834 ** 2835 ** <blockquote><pre> 2836 ** azResult[0] = "Name"; 2837 ** azResult[1] = "Age"; 2838 ** azResult[2] = "Alice"; 2839 ** azResult[3] = "43"; 2840 ** azResult[4] = "Bob"; 2841 ** azResult[5] = "28"; 2842 ** azResult[6] = "Cindy"; 2843 ** azResult[7] = "21"; 2844 ** </pre></blockquote>)^ 2845 ** 2846 ** ^The sqlite3_get_table() function evaluates one or more 2847 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2848 ** string of its 2nd parameter and returns a result table to the 2849 ** pointer given in its 3rd parameter. 2850 ** 2851 ** After the application has finished with the result from sqlite3_get_table(), 2852 ** it must pass the result table pointer to sqlite3_free_table() in order to 2853 ** release the memory that was malloced. Because of the way the 2854 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2855 ** function must not try to call [sqlite3_free()] directly. Only 2856 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2857 ** 2858 ** The sqlite3_get_table() interface is implemented as a wrapper around 2859 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2860 ** to any internal data structures of SQLite. It uses only the public 2861 ** interface defined here. As a consequence, errors that occur in the 2862 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2863 ** reflected in subsequent calls to [sqlite3_errcode()] or 2864 ** [sqlite3_errmsg()]. 2865 */ 2866 SQLITE_API int sqlite3_get_table( 2867 sqlite3 *db, /* An open database */ 2868 const char *zSql, /* SQL to be evaluated */ 2869 char ***pazResult, /* Results of the query */ 2870 int *pnRow, /* Number of result rows written here */ 2871 int *pnColumn, /* Number of result columns written here */ 2872 char **pzErrmsg /* Error msg written here */ 2873 ); 2874 SQLITE_API void sqlite3_free_table(char **result); 2875 2876 /* 2877 ** CAPI3REF: Formatted String Printing Functions 2878 ** 2879 ** These routines are work-alikes of the "printf()" family of functions 2880 ** from the standard C library. 2881 ** These routines understand most of the common formatting options from 2882 ** the standard library printf() 2883 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2884 ** See the [built-in printf()] documentation for details. 2885 ** 2886 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2887 ** results into memory obtained from [sqlite3_malloc64()]. 2888 ** The strings returned by these two routines should be 2889 ** released by [sqlite3_free()]. ^Both routines return a 2890 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2891 ** memory to hold the resulting string. 2892 ** 2893 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2894 ** the standard C library. The result is written into the 2895 ** buffer supplied as the second parameter whose size is given by 2896 ** the first parameter. Note that the order of the 2897 ** first two parameters is reversed from snprintf().)^ This is an 2898 ** historical accident that cannot be fixed without breaking 2899 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2900 ** returns a pointer to its buffer instead of the number of 2901 ** characters actually written into the buffer.)^ We admit that 2902 ** the number of characters written would be a more useful return 2903 ** value but we cannot change the implementation of sqlite3_snprintf() 2904 ** now without breaking compatibility. 2905 ** 2906 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2907 ** guarantees that the buffer is always zero-terminated. ^The first 2908 ** parameter "n" is the total size of the buffer, including space for 2909 ** the zero terminator. So the longest string that can be completely 2910 ** written will be n-1 characters. 2911 ** 2912 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2913 ** 2914 ** See also: [built-in printf()], [printf() SQL function] 2915 */ 2916 SQLITE_API char *sqlite3_mprintf(const char*,...); 2917 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2918 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2919 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2920 2921 /* 2922 ** CAPI3REF: Memory Allocation Subsystem 2923 ** 2924 ** The SQLite core uses these three routines for all of its own 2925 ** internal memory allocation needs. "Core" in the previous sentence 2926 ** does not include operating-system specific [VFS] implementation. The 2927 ** Windows VFS uses native malloc() and free() for some operations. 2928 ** 2929 ** ^The sqlite3_malloc() routine returns a pointer to a block 2930 ** of memory at least N bytes in length, where N is the parameter. 2931 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2932 ** memory, it returns a NULL pointer. ^If the parameter N to 2933 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2934 ** a NULL pointer. 2935 ** 2936 ** ^The sqlite3_malloc64(N) routine works just like 2937 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2938 ** of a signed 32-bit integer. 2939 ** 2940 ** ^Calling sqlite3_free() with a pointer previously returned 2941 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2942 ** that it might be reused. ^The sqlite3_free() routine is 2943 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2944 ** to sqlite3_free() is harmless. After being freed, memory 2945 ** should neither be read nor written. Even reading previously freed 2946 ** memory might result in a segmentation fault or other severe error. 2947 ** Memory corruption, a segmentation fault, or other severe error 2948 ** might result if sqlite3_free() is called with a non-NULL pointer that 2949 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2950 ** 2951 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2952 ** prior memory allocation X to be at least N bytes. 2953 ** ^If the X parameter to sqlite3_realloc(X,N) 2954 ** is a NULL pointer then its behavior is identical to calling 2955 ** sqlite3_malloc(N). 2956 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2957 ** negative then the behavior is exactly the same as calling 2958 ** sqlite3_free(X). 2959 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2960 ** of at least N bytes in size or NULL if insufficient memory is available. 2961 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2962 ** of the prior allocation are copied into the beginning of buffer returned 2963 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2964 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2965 ** prior allocation is not freed. 2966 ** 2967 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2968 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2969 ** of a 32-bit signed integer. 2970 ** 2971 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2972 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2973 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2974 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2975 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2976 ** sqlite3_msize(X) returns zero. If X points to something that is not 2977 ** the beginning of memory allocation, or if it points to a formerly 2978 ** valid memory allocation that has now been freed, then the behavior 2979 ** of sqlite3_msize(X) is undefined and possibly harmful. 2980 ** 2981 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2982 ** sqlite3_malloc64(), and sqlite3_realloc64() 2983 ** is always aligned to at least an 8 byte boundary, or to a 2984 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2985 ** option is used. 2986 ** 2987 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2988 ** must be either NULL or else pointers obtained from a prior 2989 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2990 ** not yet been released. 2991 ** 2992 ** The application must not read or write any part of 2993 ** a block of memory after it has been released using 2994 ** [sqlite3_free()] or [sqlite3_realloc()]. 2995 */ 2996 SQLITE_API void *sqlite3_malloc(int); 2997 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2998 SQLITE_API void *sqlite3_realloc(void*, int); 2999 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 3000 SQLITE_API void sqlite3_free(void*); 3001 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 3002 3003 /* 3004 ** CAPI3REF: Memory Allocator Statistics 3005 ** 3006 ** SQLite provides these two interfaces for reporting on the status 3007 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 3008 ** routines, which form the built-in memory allocation subsystem. 3009 ** 3010 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 3011 ** of memory currently outstanding (malloced but not freed). 3012 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 3013 ** value of [sqlite3_memory_used()] since the high-water mark 3014 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 3015 ** [sqlite3_memory_highwater()] include any overhead 3016 ** added by SQLite in its implementation of [sqlite3_malloc()], 3017 ** but not overhead added by the any underlying system library 3018 ** routines that [sqlite3_malloc()] may call. 3019 ** 3020 ** ^The memory high-water mark is reset to the current value of 3021 ** [sqlite3_memory_used()] if and only if the parameter to 3022 ** [sqlite3_memory_highwater()] is true. ^The value returned 3023 ** by [sqlite3_memory_highwater(1)] is the high-water mark 3024 ** prior to the reset. 3025 */ 3026 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 3027 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 3028 3029 /* 3030 ** CAPI3REF: Pseudo-Random Number Generator 3031 ** 3032 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3033 ** select random [ROWID | ROWIDs] when inserting new records into a table that 3034 ** already uses the largest possible [ROWID]. The PRNG is also used for 3035 ** the built-in random() and randomblob() SQL functions. This interface allows 3036 ** applications to access the same PRNG for other purposes. 3037 ** 3038 ** ^A call to this routine stores N bytes of randomness into buffer P. 3039 ** ^The P parameter can be a NULL pointer. 3040 ** 3041 ** ^If this routine has not been previously called or if the previous 3042 ** call had N less than one or a NULL pointer for P, then the PRNG is 3043 ** seeded using randomness obtained from the xRandomness method of 3044 ** the default [sqlite3_vfs] object. 3045 ** ^If the previous call to this routine had an N of 1 or more and a 3046 ** non-NULL P then the pseudo-randomness is generated 3047 ** internally and without recourse to the [sqlite3_vfs] xRandomness 3048 ** method. 3049 */ 3050 SQLITE_API void sqlite3_randomness(int N, void *P); 3051 3052 /* 3053 ** CAPI3REF: Compile-Time Authorization Callbacks 3054 ** METHOD: sqlite3 3055 ** KEYWORDS: {authorizer callback} 3056 ** 3057 ** ^This routine registers an authorizer callback with a particular 3058 ** [database connection], supplied in the first argument. 3059 ** ^The authorizer callback is invoked as SQL statements are being compiled 3060 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3061 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3062 ** and [sqlite3_prepare16_v3()]. ^At various 3063 ** points during the compilation process, as logic is being created 3064 ** to perform various actions, the authorizer callback is invoked to 3065 ** see if those actions are allowed. ^The authorizer callback should 3066 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3067 ** specific action but allow the SQL statement to continue to be 3068 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3069 ** rejected with an error. ^If the authorizer callback returns 3070 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3071 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3072 ** the authorizer will fail with an error message. 3073 ** 3074 ** When the callback returns [SQLITE_OK], that means the operation 3075 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 3076 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3077 ** authorizer will fail with an error message explaining that 3078 ** access is denied. 3079 ** 3080 ** ^The first parameter to the authorizer callback is a copy of the third 3081 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3082 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3083 ** the particular action to be authorized. ^The third through sixth parameters 3084 ** to the callback are either NULL pointers or zero-terminated strings 3085 ** that contain additional details about the action to be authorized. 3086 ** Applications must always be prepared to encounter a NULL pointer in any 3087 ** of the third through the sixth parameters of the authorization callback. 3088 ** 3089 ** ^If the action code is [SQLITE_READ] 3090 ** and the callback returns [SQLITE_IGNORE] then the 3091 ** [prepared statement] statement is constructed to substitute 3092 ** a NULL value in place of the table column that would have 3093 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3094 ** return can be used to deny an untrusted user access to individual 3095 ** columns of a table. 3096 ** ^When a table is referenced by a [SELECT] but no column values are 3097 ** extracted from that table (for example in a query like 3098 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3099 ** is invoked once for that table with a column name that is an empty string. 3100 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3101 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3102 ** [truncate optimization] is disabled and all rows are deleted individually. 3103 ** 3104 ** An authorizer is used when [sqlite3_prepare | preparing] 3105 ** SQL statements from an untrusted source, to ensure that the SQL statements 3106 ** do not try to access data they are not allowed to see, or that they do not 3107 ** try to execute malicious statements that damage the database. For 3108 ** example, an application may allow a user to enter arbitrary 3109 ** SQL queries for evaluation by a database. But the application does 3110 ** not want the user to be able to make arbitrary changes to the 3111 ** database. An authorizer could then be put in place while the 3112 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3113 ** disallows everything except [SELECT] statements. 3114 ** 3115 ** Applications that need to process SQL from untrusted sources 3116 ** might also consider lowering resource limits using [sqlite3_limit()] 3117 ** and limiting database size using the [max_page_count] [PRAGMA] 3118 ** in addition to using an authorizer. 3119 ** 3120 ** ^(Only a single authorizer can be in place on a database connection 3121 ** at a time. Each call to sqlite3_set_authorizer overrides the 3122 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3123 ** The authorizer is disabled by default. 3124 ** 3125 ** The authorizer callback must not do anything that will modify 3126 ** the database connection that invoked the authorizer callback. 3127 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3128 ** database connections for the meaning of "modify" in this paragraph. 3129 ** 3130 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3131 ** statement might be re-prepared during [sqlite3_step()] due to a 3132 ** schema change. Hence, the application should ensure that the 3133 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3134 ** 3135 ** ^Note that the authorizer callback is invoked only during 3136 ** [sqlite3_prepare()] or its variants. Authorization is not 3137 ** performed during statement evaluation in [sqlite3_step()], unless 3138 ** as stated in the previous paragraph, sqlite3_step() invokes 3139 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3140 */ 3141 SQLITE_API int sqlite3_set_authorizer( 3142 sqlite3*, 3143 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3144 void *pUserData 3145 ); 3146 3147 /* 3148 ** CAPI3REF: Authorizer Return Codes 3149 ** 3150 ** The [sqlite3_set_authorizer | authorizer callback function] must 3151 ** return either [SQLITE_OK] or one of these two constants in order 3152 ** to signal SQLite whether or not the action is permitted. See the 3153 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3154 ** information. 3155 ** 3156 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3157 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3158 */ 3159 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3160 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3161 3162 /* 3163 ** CAPI3REF: Authorizer Action Codes 3164 ** 3165 ** The [sqlite3_set_authorizer()] interface registers a callback function 3166 ** that is invoked to authorize certain SQL statement actions. The 3167 ** second parameter to the callback is an integer code that specifies 3168 ** what action is being authorized. These are the integer action codes that 3169 ** the authorizer callback may be passed. 3170 ** 3171 ** These action code values signify what kind of operation is to be 3172 ** authorized. The 3rd and 4th parameters to the authorization 3173 ** callback function will be parameters or NULL depending on which of these 3174 ** codes is used as the second parameter. ^(The 5th parameter to the 3175 ** authorizer callback is the name of the database ("main", "temp", 3176 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3177 ** is the name of the inner-most trigger or view that is responsible for 3178 ** the access attempt or NULL if this access attempt is directly from 3179 ** top-level SQL code. 3180 */ 3181 /******************************************* 3rd ************ 4th ***********/ 3182 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3183 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3184 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3185 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3186 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3187 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3188 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3189 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3190 #define SQLITE_DELETE 9 /* Table Name NULL */ 3191 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3192 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3193 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3194 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3195 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3196 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3197 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3198 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3199 #define SQLITE_INSERT 18 /* Table Name NULL */ 3200 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3201 #define SQLITE_READ 20 /* Table Name Column Name */ 3202 #define SQLITE_SELECT 21 /* NULL NULL */ 3203 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3204 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3205 #define SQLITE_ATTACH 24 /* Filename NULL */ 3206 #define SQLITE_DETACH 25 /* Database Name NULL */ 3207 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3208 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3209 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3210 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3211 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3212 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3213 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3214 #define SQLITE_COPY 0 /* No longer used */ 3215 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3216 3217 /* 3218 ** CAPI3REF: Tracing And Profiling Functions 3219 ** METHOD: sqlite3 3220 ** 3221 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3222 ** instead of the routines described here. 3223 ** 3224 ** These routines register callback functions that can be used for 3225 ** tracing and profiling the execution of SQL statements. 3226 ** 3227 ** ^The callback function registered by sqlite3_trace() is invoked at 3228 ** various times when an SQL statement is being run by [sqlite3_step()]. 3229 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3230 ** SQL statement text as the statement first begins executing. 3231 ** ^(Additional sqlite3_trace() callbacks might occur 3232 ** as each triggered subprogram is entered. The callbacks for triggers 3233 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3234 ** 3235 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3236 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3237 ** 3238 ** ^The callback function registered by sqlite3_profile() is invoked 3239 ** as each SQL statement finishes. ^The profile callback contains 3240 ** the original statement text and an estimate of wall-clock time 3241 ** of how long that statement took to run. ^The profile callback 3242 ** time is in units of nanoseconds, however the current implementation 3243 ** is only capable of millisecond resolution so the six least significant 3244 ** digits in the time are meaningless. Future versions of SQLite 3245 ** might provide greater resolution on the profiler callback. Invoking 3246 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3247 ** profile callback. 3248 */ 3249 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3250 void(*xTrace)(void*,const char*), void*); 3251 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3252 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3253 3254 /* 3255 ** CAPI3REF: SQL Trace Event Codes 3256 ** KEYWORDS: SQLITE_TRACE 3257 ** 3258 ** These constants identify classes of events that can be monitored 3259 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3260 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3261 ** the following constants. ^The first argument to the trace callback 3262 ** is one of the following constants. 3263 ** 3264 ** New tracing constants may be added in future releases. 3265 ** 3266 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3267 ** ^The T argument is one of the integer type codes above. 3268 ** ^The C argument is a copy of the context pointer passed in as the 3269 ** fourth argument to [sqlite3_trace_v2()]. 3270 ** The P and X arguments are pointers whose meanings depend on T. 3271 ** 3272 ** <dl> 3273 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3274 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3275 ** first begins running and possibly at other times during the 3276 ** execution of the prepared statement, such as at the start of each 3277 ** trigger subprogram. ^The P argument is a pointer to the 3278 ** [prepared statement]. ^The X argument is a pointer to a string which 3279 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3280 ** that indicates the invocation of a trigger. ^The callback can compute 3281 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3282 ** interface by using the X argument when X begins with "--" and invoking 3283 ** [sqlite3_expanded_sql(P)] otherwise. 3284 ** 3285 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3286 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3287 ** information as is provided by the [sqlite3_profile()] callback. 3288 ** ^The P argument is a pointer to the [prepared statement] and the 3289 ** X argument points to a 64-bit integer which is the estimated of 3290 ** the number of nanosecond that the prepared statement took to run. 3291 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3292 ** 3293 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3294 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3295 ** statement generates a single row of result. 3296 ** ^The P argument is a pointer to the [prepared statement] and the 3297 ** X argument is unused. 3298 ** 3299 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3300 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3301 ** connection closes. 3302 ** ^The P argument is a pointer to the [database connection] object 3303 ** and the X argument is unused. 3304 ** </dl> 3305 */ 3306 #define SQLITE_TRACE_STMT 0x01 3307 #define SQLITE_TRACE_PROFILE 0x02 3308 #define SQLITE_TRACE_ROW 0x04 3309 #define SQLITE_TRACE_CLOSE 0x08 3310 3311 /* 3312 ** CAPI3REF: SQL Trace Hook 3313 ** METHOD: sqlite3 3314 ** 3315 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3316 ** function X against [database connection] D, using property mask M 3317 ** and context pointer P. ^If the X callback is 3318 ** NULL or if the M mask is zero, then tracing is disabled. The 3319 ** M argument should be the bitwise OR-ed combination of 3320 ** zero or more [SQLITE_TRACE] constants. 3321 ** 3322 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3323 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3324 ** 3325 ** ^The X callback is invoked whenever any of the events identified by 3326 ** mask M occur. ^The integer return value from the callback is currently 3327 ** ignored, though this may change in future releases. Callback 3328 ** implementations should return zero to ensure future compatibility. 3329 ** 3330 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3331 ** ^The T argument is one of the [SQLITE_TRACE] 3332 ** constants to indicate why the callback was invoked. 3333 ** ^The C argument is a copy of the context pointer. 3334 ** The P and X arguments are pointers whose meanings depend on T. 3335 ** 3336 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3337 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3338 ** are deprecated. 3339 */ 3340 SQLITE_API int sqlite3_trace_v2( 3341 sqlite3*, 3342 unsigned uMask, 3343 int(*xCallback)(unsigned,void*,void*,void*), 3344 void *pCtx 3345 ); 3346 3347 /* 3348 ** CAPI3REF: Query Progress Callbacks 3349 ** METHOD: sqlite3 3350 ** 3351 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3352 ** function X to be invoked periodically during long running calls to 3353 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3354 ** database connection D. An example use for this 3355 ** interface is to keep a GUI updated during a large query. 3356 ** 3357 ** ^The parameter P is passed through as the only parameter to the 3358 ** callback function X. ^The parameter N is the approximate number of 3359 ** [virtual machine instructions] that are evaluated between successive 3360 ** invocations of the callback X. ^If N is less than one then the progress 3361 ** handler is disabled. 3362 ** 3363 ** ^Only a single progress handler may be defined at one time per 3364 ** [database connection]; setting a new progress handler cancels the 3365 ** old one. ^Setting parameter X to NULL disables the progress handler. 3366 ** ^The progress handler is also disabled by setting N to a value less 3367 ** than 1. 3368 ** 3369 ** ^If the progress callback returns non-zero, the operation is 3370 ** interrupted. This feature can be used to implement a 3371 ** "Cancel" button on a GUI progress dialog box. 3372 ** 3373 ** The progress handler callback must not do anything that will modify 3374 ** the database connection that invoked the progress handler. 3375 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3376 ** database connections for the meaning of "modify" in this paragraph. 3377 ** 3378 */ 3379 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3380 3381 /* 3382 ** CAPI3REF: Opening A New Database Connection 3383 ** CONSTRUCTOR: sqlite3 3384 ** 3385 ** ^These routines open an SQLite database file as specified by the 3386 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3387 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3388 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3389 ** returned in *ppDb, even if an error occurs. The only exception is that 3390 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3391 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3392 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3393 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3394 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3395 ** an English language description of the error following a failure of any 3396 ** of the sqlite3_open() routines. 3397 ** 3398 ** ^The default encoding will be UTF-8 for databases created using 3399 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3400 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3401 ** 3402 ** Whether or not an error occurs when it is opened, resources 3403 ** associated with the [database connection] handle should be released by 3404 ** passing it to [sqlite3_close()] when it is no longer required. 3405 ** 3406 ** The sqlite3_open_v2() interface works like sqlite3_open() 3407 ** except that it accepts two additional parameters for additional control 3408 ** over the new database connection. ^(The flags parameter to 3409 ** sqlite3_open_v2() must include, at a minimum, one of the following 3410 ** three flag combinations:)^ 3411 ** 3412 ** <dl> 3413 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3414 ** <dd>The database is opened in read-only mode. If the database does not 3415 ** already exist, an error is returned.</dd>)^ 3416 ** 3417 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3418 ** <dd>The database is opened for reading and writing if possible, or reading 3419 ** only if the file is write protected by the operating system. In either 3420 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3421 ** 3422 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3423 ** <dd>The database is opened for reading and writing, and is created if 3424 ** it does not already exist. This is the behavior that is always used for 3425 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3426 ** </dl> 3427 ** 3428 ** In addition to the required flags, the following optional flags are 3429 ** also supported: 3430 ** 3431 ** <dl> 3432 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3433 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3434 ** 3435 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3436 ** <dd>The database will be opened as an in-memory database. The database 3437 ** is named by the "filename" argument for the purposes of cache-sharing, 3438 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3439 ** </dd>)^ 3440 ** 3441 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3442 ** <dd>The new database connection will use the "multi-thread" 3443 ** [threading mode].)^ This means that separate threads are allowed 3444 ** to use SQLite at the same time, as long as each thread is using 3445 ** a different [database connection]. 3446 ** 3447 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3448 ** <dd>The new database connection will use the "serialized" 3449 ** [threading mode].)^ This means the multiple threads can safely 3450 ** attempt to use the same database connection at the same time. 3451 ** (Mutexes will block any actual concurrency, but in this mode 3452 ** there is no harm in trying.) 3453 ** 3454 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3455 ** <dd>The database is opened [shared cache] enabled, overriding 3456 ** the default shared cache setting provided by 3457 ** [sqlite3_enable_shared_cache()].)^ 3458 ** The [use of shared cache mode is discouraged] and hence shared cache 3459 ** capabilities may be omitted from many builds of SQLite. In such cases, 3460 ** this option is a no-op. 3461 ** 3462 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3463 ** <dd>The database is opened [shared cache] disabled, overriding 3464 ** the default shared cache setting provided by 3465 ** [sqlite3_enable_shared_cache()].)^ 3466 ** 3467 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3468 ** <dd>The database connection comes up in "extended result code mode". 3469 ** In other words, the database behaves has if 3470 ** [sqlite3_extended_result_codes(db,1)] where called on the database 3471 ** connection as soon as the connection is created. In addition to setting 3472 ** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3473 ** to return an extended result code.</dd> 3474 ** 3475 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3476 ** <dd>The database filename is not allowed to contain a symbolic link</dd> 3477 ** </dl>)^ 3478 ** 3479 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3480 ** required combinations shown above optionally combined with other 3481 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3482 ** then the behavior is undefined. Historic versions of SQLite 3483 ** have silently ignored surplus bits in the flags parameter to 3484 ** sqlite3_open_v2(), however that behavior might not be carried through 3485 ** into future versions of SQLite and so applications should not rely 3486 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3487 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3488 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3489 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3490 ** by sqlite3_open_v2(). 3491 ** 3492 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3493 ** [sqlite3_vfs] object that defines the operating system interface that 3494 ** the new database connection should use. ^If the fourth parameter is 3495 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3496 ** 3497 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3498 ** is created for the connection. ^This in-memory database will vanish when 3499 ** the database connection is closed. Future versions of SQLite might 3500 ** make use of additional special filenames that begin with the ":" character. 3501 ** It is recommended that when a database filename actually does begin with 3502 ** a ":" character you should prefix the filename with a pathname such as 3503 ** "./" to avoid ambiguity. 3504 ** 3505 ** ^If the filename is an empty string, then a private, temporary 3506 ** on-disk database will be created. ^This private database will be 3507 ** automatically deleted as soon as the database connection is closed. 3508 ** 3509 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3510 ** 3511 ** ^If [URI filename] interpretation is enabled, and the filename argument 3512 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3513 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3514 ** set in the third argument to sqlite3_open_v2(), or if it has 3515 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3516 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3517 ** URI filename interpretation is turned off 3518 ** by default, but future releases of SQLite might enable URI filename 3519 ** interpretation by default. See "[URI filenames]" for additional 3520 ** information. 3521 ** 3522 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3523 ** authority, then it must be either an empty string or the string 3524 ** "localhost". ^If the authority is not an empty string or "localhost", an 3525 ** error is returned to the caller. ^The fragment component of a URI, if 3526 ** present, is ignored. 3527 ** 3528 ** ^SQLite uses the path component of the URI as the name of the disk file 3529 ** which contains the database. ^If the path begins with a '/' character, 3530 ** then it is interpreted as an absolute path. ^If the path does not begin 3531 ** with a '/' (meaning that the authority section is omitted from the URI) 3532 ** then the path is interpreted as a relative path. 3533 ** ^(On windows, the first component of an absolute path 3534 ** is a drive specification (e.g. "C:").)^ 3535 ** 3536 ** [[core URI query parameters]] 3537 ** The query component of a URI may contain parameters that are interpreted 3538 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3539 ** SQLite and its built-in [VFSes] interpret the 3540 ** following query parameters: 3541 ** 3542 ** <ul> 3543 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3544 ** a VFS object that provides the operating system interface that should 3545 ** be used to access the database file on disk. ^If this option is set to 3546 ** an empty string the default VFS object is used. ^Specifying an unknown 3547 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3548 ** present, then the VFS specified by the option takes precedence over 3549 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3550 ** 3551 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3552 ** "rwc", or "memory". Attempting to set it to any other value is 3553 ** an error)^. 3554 ** ^If "ro" is specified, then the database is opened for read-only 3555 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3556 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3557 ** "rw", then the database is opened for read-write (but not create) 3558 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3559 ** been set. ^Value "rwc" is equivalent to setting both 3560 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3561 ** set to "memory" then a pure [in-memory database] that never reads 3562 ** or writes from disk is used. ^It is an error to specify a value for 3563 ** the mode parameter that is less restrictive than that specified by 3564 ** the flags passed in the third parameter to sqlite3_open_v2(). 3565 ** 3566 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3567 ** "private". ^Setting it to "shared" is equivalent to setting the 3568 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3569 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3570 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3571 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3572 ** a URI filename, its value overrides any behavior requested by setting 3573 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3574 ** 3575 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3576 ** [powersafe overwrite] property does or does not apply to the 3577 ** storage media on which the database file resides. 3578 ** 3579 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3580 ** which if set disables file locking in rollback journal modes. This 3581 ** is useful for accessing a database on a filesystem that does not 3582 ** support locking. Caution: Database corruption might result if two 3583 ** or more processes write to the same database and any one of those 3584 ** processes uses nolock=1. 3585 ** 3586 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3587 ** parameter that indicates that the database file is stored on 3588 ** read-only media. ^When immutable is set, SQLite assumes that the 3589 ** database file cannot be changed, even by a process with higher 3590 ** privilege, and so the database is opened read-only and all locking 3591 ** and change detection is disabled. Caution: Setting the immutable 3592 ** property on a database file that does in fact change can result 3593 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3594 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3595 ** 3596 ** </ul> 3597 ** 3598 ** ^Specifying an unknown parameter in the query component of a URI is not an 3599 ** error. Future versions of SQLite might understand additional query 3600 ** parameters. See "[query parameters with special meaning to SQLite]" for 3601 ** additional information. 3602 ** 3603 ** [[URI filename examples]] <h3>URI filename examples</h3> 3604 ** 3605 ** <table border="1" align=center cellpadding=5> 3606 ** <tr><th> URI filenames <th> Results 3607 ** <tr><td> file:data.db <td> 3608 ** Open the file "data.db" in the current directory. 3609 ** <tr><td> file:/home/fred/data.db<br> 3610 ** file:///home/fred/data.db <br> 3611 ** file://localhost/home/fred/data.db <br> <td> 3612 ** Open the database file "/home/fred/data.db". 3613 ** <tr><td> file://darkstar/home/fred/data.db <td> 3614 ** An error. "darkstar" is not a recognized authority. 3615 ** <tr><td style="white-space:nowrap"> 3616 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3617 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3618 ** C:. Note that the %20 escaping in this example is not strictly 3619 ** necessary - space characters can be used literally 3620 ** in URI filenames. 3621 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3622 ** Open file "data.db" in the current directory for read-only access. 3623 ** Regardless of whether or not shared-cache mode is enabled by 3624 ** default, use a private cache. 3625 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3626 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3627 ** that uses dot-files in place of posix advisory locking. 3628 ** <tr><td> file:data.db?mode=readonly <td> 3629 ** An error. "readonly" is not a valid option for the "mode" parameter. 3630 ** Use "ro" instead: "file:data.db?mode=ro". 3631 ** </table> 3632 ** 3633 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3634 ** query components of a URI. A hexadecimal escape sequence consists of a 3635 ** percent sign - "%" - followed by exactly two hexadecimal digits 3636 ** specifying an octet value. ^Before the path or query components of a 3637 ** URI filename are interpreted, they are encoded using UTF-8 and all 3638 ** hexadecimal escape sequences replaced by a single byte containing the 3639 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3640 ** the results are undefined. 3641 ** 3642 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3643 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3644 ** codepage is currently defined. Filenames containing international 3645 ** characters must be converted to UTF-8 prior to passing them into 3646 ** sqlite3_open() or sqlite3_open_v2(). 3647 ** 3648 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3649 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3650 ** features that require the use of temporary files may fail. 3651 ** 3652 ** See also: [sqlite3_temp_directory] 3653 */ 3654 SQLITE_API int sqlite3_open( 3655 const char *filename, /* Database filename (UTF-8) */ 3656 sqlite3 **ppDb /* OUT: SQLite db handle */ 3657 ); 3658 SQLITE_API int sqlite3_open16( 3659 const void *filename, /* Database filename (UTF-16) */ 3660 sqlite3 **ppDb /* OUT: SQLite db handle */ 3661 ); 3662 SQLITE_API int sqlite3_open_v2( 3663 const char *filename, /* Database filename (UTF-8) */ 3664 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3665 int flags, /* Flags */ 3666 const char *zVfs /* Name of VFS module to use */ 3667 ); 3668 3669 /* 3670 ** CAPI3REF: Obtain Values For URI Parameters 3671 ** 3672 ** These are utility routines, useful to [VFS|custom VFS implementations], 3673 ** that check if a database file was a URI that contained a specific query 3674 ** parameter, and if so obtains the value of that query parameter. 3675 ** 3676 ** The first parameter to these interfaces (hereafter referred to 3677 ** as F) must be one of: 3678 ** <ul> 3679 ** <li> A database filename pointer created by the SQLite core and 3680 ** passed into the xOpen() method of a VFS implemention, or 3681 ** <li> A filename obtained from [sqlite3_db_filename()], or 3682 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3683 ** </ul> 3684 ** If the F parameter is not one of the above, then the behavior is 3685 ** undefined and probably undesirable. Older versions of SQLite were 3686 ** more tolerant of invalid F parameters than newer versions. 3687 ** 3688 ** If F is a suitable filename (as described in the previous paragraph) 3689 ** and if P is the name of the query parameter, then 3690 ** sqlite3_uri_parameter(F,P) returns the value of the P 3691 ** parameter if it exists or a NULL pointer if P does not appear as a 3692 ** query parameter on F. If P is a query parameter of F and it 3693 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3694 ** a pointer to an empty string. 3695 ** 3696 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3697 ** parameter and returns true (1) or false (0) according to the value 3698 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3699 ** value of query parameter P is one of "yes", "true", or "on" in any 3700 ** case or if the value begins with a non-zero number. The 3701 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3702 ** query parameter P is one of "no", "false", or "off" in any case or 3703 ** if the value begins with a numeric zero. If P is not a query 3704 ** parameter on F or if the value of P does not match any of the 3705 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3706 ** 3707 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3708 ** 64-bit signed integer and returns that integer, or D if P does not 3709 ** exist. If the value of P is something other than an integer, then 3710 ** zero is returned. 3711 ** 3712 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3713 ** the value) of the N-th query parameter for filename F, or a NULL 3714 ** pointer if N is less than zero or greater than the number of query 3715 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3716 ** the name of the first query parameter, 1 for the second parameter, and 3717 ** so forth. 3718 ** 3719 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3720 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3721 ** is not a database file pathname pointer that the SQLite core passed 3722 ** into the xOpen VFS method, then the behavior of this routine is undefined 3723 ** and probably undesirable. 3724 ** 3725 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3726 ** parameter can also be the name of a rollback journal file or WAL file 3727 ** in addition to the main database file. Prior to version 3.31.0, these 3728 ** routines would only work if F was the name of the main database file. 3729 ** When the F parameter is the name of the rollback journal or WAL file, 3730 ** it has access to all the same query parameters as were found on the 3731 ** main database file. 3732 ** 3733 ** See the [URI filename] documentation for additional information. 3734 */ 3735 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); 3736 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); 3737 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); 3738 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N); 3739 3740 /* 3741 ** CAPI3REF: Translate filenames 3742 ** 3743 ** These routines are available to [VFS|custom VFS implementations] for 3744 ** translating filenames between the main database file, the journal file, 3745 ** and the WAL file. 3746 ** 3747 ** If F is the name of an sqlite database file, journal file, or WAL file 3748 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3749 ** returns the name of the corresponding database file. 3750 ** 3751 ** If F is the name of an sqlite database file, journal file, or WAL file 3752 ** passed by the SQLite core into the VFS, or if F is a database filename 3753 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3754 ** returns the name of the corresponding rollback journal file. 3755 ** 3756 ** If F is the name of an sqlite database file, journal file, or WAL file 3757 ** that was passed by the SQLite core into the VFS, or if F is a database 3758 ** filename obtained from [sqlite3_db_filename()], then 3759 ** sqlite3_filename_wal(F) returns the name of the corresponding 3760 ** WAL file. 3761 ** 3762 ** In all of the above, if F is not the name of a database, journal or WAL 3763 ** filename passed into the VFS from the SQLite core and F is not the 3764 ** return value from [sqlite3_db_filename()], then the result is 3765 ** undefined and is likely a memory access violation. 3766 */ 3767 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename); 3768 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename); 3769 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename); 3770 3771 /* 3772 ** CAPI3REF: Database File Corresponding To A Journal 3773 ** 3774 ** ^If X is the name of a rollback or WAL-mode journal file that is 3775 ** passed into the xOpen method of [sqlite3_vfs], then 3776 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3777 ** object that represents the main database file. 3778 ** 3779 ** This routine is intended for use in custom [VFS] implementations 3780 ** only. It is not a general-purpose interface. 3781 ** The argument sqlite3_file_object(X) must be a filename pointer that 3782 ** has been passed into [sqlite3_vfs].xOpen method where the 3783 ** flags parameter to xOpen contains one of the bits 3784 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3785 ** of this routine results in undefined and probably undesirable 3786 ** behavior. 3787 */ 3788 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3789 3790 /* 3791 ** CAPI3REF: Create and Destroy VFS Filenames 3792 ** 3793 ** These interfces are provided for use by [VFS shim] implementations and 3794 ** are not useful outside of that context. 3795 ** 3796 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3797 ** database filename D with corresponding journal file J and WAL file W and 3798 ** with N URI parameters key/values pairs in the array P. The result from 3799 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3800 ** is safe to pass to routines like: 3801 ** <ul> 3802 ** <li> [sqlite3_uri_parameter()], 3803 ** <li> [sqlite3_uri_boolean()], 3804 ** <li> [sqlite3_uri_int64()], 3805 ** <li> [sqlite3_uri_key()], 3806 ** <li> [sqlite3_filename_database()], 3807 ** <li> [sqlite3_filename_journal()], or 3808 ** <li> [sqlite3_filename_wal()]. 3809 ** </ul> 3810 ** If a memory allocation error occurs, sqlite3_create_filename() might 3811 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3812 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3813 ** 3814 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3815 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3816 ** to a key and value for a query parameter. The P parameter may be a NULL 3817 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3818 ** NULL pointers and key pointers should not be empty strings. 3819 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3820 ** be NULL pointers, though they can be empty strings. 3821 ** 3822 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3823 ** previously obtained from sqlite3_create_filename(). Invoking 3824 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3825 ** 3826 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3827 ** than a NULL pointer or a pointer previously acquired from 3828 ** sqlite3_create_filename(), then bad things such as heap 3829 ** corruption or segfaults may occur. The value Y should not be 3830 ** used again after sqlite3_free_filename(Y) has been called. This means 3831 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3832 ** then the corresponding [sqlite3_module.xClose() method should also be 3833 ** invoked prior to calling sqlite3_free_filename(Y). 3834 */ 3835 SQLITE_API sqlite3_filename sqlite3_create_filename( 3836 const char *zDatabase, 3837 const char *zJournal, 3838 const char *zWal, 3839 int nParam, 3840 const char **azParam 3841 ); 3842 SQLITE_API void sqlite3_free_filename(sqlite3_filename); 3843 3844 /* 3845 ** CAPI3REF: Error Codes And Messages 3846 ** METHOD: sqlite3 3847 ** 3848 ** ^If the most recent sqlite3_* API call associated with 3849 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3850 ** returns the numeric [result code] or [extended result code] for that 3851 ** API call. 3852 ** ^The sqlite3_extended_errcode() 3853 ** interface is the same except that it always returns the 3854 ** [extended result code] even when extended result codes are 3855 ** disabled. 3856 ** 3857 ** The values returned by sqlite3_errcode() and/or 3858 ** sqlite3_extended_errcode() might change with each API call. 3859 ** Except, there are some interfaces that are guaranteed to never 3860 ** change the value of the error code. The error-code preserving 3861 ** interfaces include the following: 3862 ** 3863 ** <ul> 3864 ** <li> sqlite3_errcode() 3865 ** <li> sqlite3_extended_errcode() 3866 ** <li> sqlite3_errmsg() 3867 ** <li> sqlite3_errmsg16() 3868 ** <li> sqlite3_error_offset() 3869 ** </ul> 3870 ** 3871 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3872 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3873 ** ^(Memory to hold the error message string is managed internally. 3874 ** The application does not need to worry about freeing the result. 3875 ** However, the error string might be overwritten or deallocated by 3876 ** subsequent calls to other SQLite interface functions.)^ 3877 ** 3878 ** ^The sqlite3_errstr() interface returns the English-language text 3879 ** that describes the [result code], as UTF-8. 3880 ** ^(Memory to hold the error message string is managed internally 3881 ** and must not be freed by the application)^. 3882 ** 3883 ** ^If the most recent error references a specific token in the input 3884 ** SQL, the sqlite3_error_offset() interface returns the byte offset 3885 ** of the start of that token. ^The byte offset returned by 3886 ** sqlite3_error_offset() assumes that the input SQL is UTF8. 3887 ** ^If the most recent error does not reference a specific token in the input 3888 ** SQL, then the sqlite3_error_offset() function returns -1. 3889 ** 3890 ** When the serialized [threading mode] is in use, it might be the 3891 ** case that a second error occurs on a separate thread in between 3892 ** the time of the first error and the call to these interfaces. 3893 ** When that happens, the second error will be reported since these 3894 ** interfaces always report the most recent result. To avoid 3895 ** this, each thread can obtain exclusive use of the [database connection] D 3896 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3897 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3898 ** all calls to the interfaces listed here are completed. 3899 ** 3900 ** If an interface fails with SQLITE_MISUSE, that means the interface 3901 ** was invoked incorrectly by the application. In that case, the 3902 ** error code and message may or may not be set. 3903 */ 3904 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3905 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3906 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3907 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3908 SQLITE_API const char *sqlite3_errstr(int); 3909 SQLITE_API int sqlite3_error_offset(sqlite3 *db); 3910 3911 /* 3912 ** CAPI3REF: Prepared Statement Object 3913 ** KEYWORDS: {prepared statement} {prepared statements} 3914 ** 3915 ** An instance of this object represents a single SQL statement that 3916 ** has been compiled into binary form and is ready to be evaluated. 3917 ** 3918 ** Think of each SQL statement as a separate computer program. The 3919 ** original SQL text is source code. A prepared statement object 3920 ** is the compiled object code. All SQL must be converted into a 3921 ** prepared statement before it can be run. 3922 ** 3923 ** The life-cycle of a prepared statement object usually goes like this: 3924 ** 3925 ** <ol> 3926 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3927 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3928 ** interfaces. 3929 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3930 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3931 ** to step 2. Do this zero or more times. 3932 ** <li> Destroy the object using [sqlite3_finalize()]. 3933 ** </ol> 3934 */ 3935 typedef struct sqlite3_stmt sqlite3_stmt; 3936 3937 /* 3938 ** CAPI3REF: Run-time Limits 3939 ** METHOD: sqlite3 3940 ** 3941 ** ^(This interface allows the size of various constructs to be limited 3942 ** on a connection by connection basis. The first parameter is the 3943 ** [database connection] whose limit is to be set or queried. The 3944 ** second parameter is one of the [limit categories] that define a 3945 ** class of constructs to be size limited. The third parameter is the 3946 ** new limit for that construct.)^ 3947 ** 3948 ** ^If the new limit is a negative number, the limit is unchanged. 3949 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3950 ** [limits | hard upper bound] 3951 ** set at compile-time by a C preprocessor macro called 3952 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3953 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3954 ** ^Attempts to increase a limit above its hard upper bound are 3955 ** silently truncated to the hard upper bound. 3956 ** 3957 ** ^Regardless of whether or not the limit was changed, the 3958 ** [sqlite3_limit()] interface returns the prior value of the limit. 3959 ** ^Hence, to find the current value of a limit without changing it, 3960 ** simply invoke this interface with the third parameter set to -1. 3961 ** 3962 ** Run-time limits are intended for use in applications that manage 3963 ** both their own internal database and also databases that are controlled 3964 ** by untrusted external sources. An example application might be a 3965 ** web browser that has its own databases for storing history and 3966 ** separate databases controlled by JavaScript applications downloaded 3967 ** off the Internet. The internal databases can be given the 3968 ** large, default limits. Databases managed by external sources can 3969 ** be given much smaller limits designed to prevent a denial of service 3970 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3971 ** interface to further control untrusted SQL. The size of the database 3972 ** created by an untrusted script can be contained using the 3973 ** [max_page_count] [PRAGMA]. 3974 ** 3975 ** New run-time limit categories may be added in future releases. 3976 */ 3977 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3978 3979 /* 3980 ** CAPI3REF: Run-Time Limit Categories 3981 ** KEYWORDS: {limit category} {*limit categories} 3982 ** 3983 ** These constants define various performance limits 3984 ** that can be lowered at run-time using [sqlite3_limit()]. 3985 ** The synopsis of the meanings of the various limits is shown below. 3986 ** Additional information is available at [limits | Limits in SQLite]. 3987 ** 3988 ** <dl> 3989 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3990 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3991 ** 3992 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3993 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3994 ** 3995 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3996 ** <dd>The maximum number of columns in a table definition or in the 3997 ** result set of a [SELECT] or the maximum number of columns in an index 3998 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3999 ** 4000 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 4001 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 4002 ** 4003 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 4004 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 4005 ** 4006 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 4007 ** <dd>The maximum number of instructions in a virtual machine program 4008 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 4009 ** the equivalent tries to allocate space for more than this many opcodes 4010 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 4011 ** 4012 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 4013 ** <dd>The maximum number of arguments on a function.</dd>)^ 4014 ** 4015 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 4016 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 4017 ** 4018 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 4019 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 4020 ** <dd>The maximum length of the pattern argument to the [LIKE] or 4021 ** [GLOB] operators.</dd>)^ 4022 ** 4023 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 4024 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 4025 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 4026 ** 4027 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 4028 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 4029 ** 4030 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 4031 ** <dd>The maximum number of auxiliary worker threads that a single 4032 ** [prepared statement] may start.</dd>)^ 4033 ** </dl> 4034 */ 4035 #define SQLITE_LIMIT_LENGTH 0 4036 #define SQLITE_LIMIT_SQL_LENGTH 1 4037 #define SQLITE_LIMIT_COLUMN 2 4038 #define SQLITE_LIMIT_EXPR_DEPTH 3 4039 #define SQLITE_LIMIT_COMPOUND_SELECT 4 4040 #define SQLITE_LIMIT_VDBE_OP 5 4041 #define SQLITE_LIMIT_FUNCTION_ARG 6 4042 #define SQLITE_LIMIT_ATTACHED 7 4043 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4044 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 4045 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 4046 #define SQLITE_LIMIT_WORKER_THREADS 11 4047 4048 /* 4049 ** CAPI3REF: Prepare Flags 4050 ** 4051 ** These constants define various flags that can be passed into 4052 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4053 ** [sqlite3_prepare16_v3()] interfaces. 4054 ** 4055 ** New flags may be added in future releases of SQLite. 4056 ** 4057 ** <dl> 4058 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4059 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4060 ** that the prepared statement will be retained for a long time and 4061 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4062 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4063 ** be used just once or at most a few times and then destroyed using 4064 ** [sqlite3_finalize()] relatively soon. The current implementation acts 4065 ** on this hint by avoiding the use of [lookaside memory] so as not to 4066 ** deplete the limited store of lookaside memory. Future versions of 4067 ** SQLite may act on this hint differently. 4068 ** 4069 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4070 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4071 ** to be required for any prepared statement that wanted to use the 4072 ** [sqlite3_normalized_sql()] interface. However, the 4073 ** [sqlite3_normalized_sql()] interface is now available to all 4074 ** prepared statements, regardless of whether or not they use this 4075 ** flag. 4076 ** 4077 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4078 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4079 ** to return an error (error code SQLITE_ERROR) if the statement uses 4080 ** any virtual tables. 4081 ** </dl> 4082 */ 4083 #define SQLITE_PREPARE_PERSISTENT 0x01 4084 #define SQLITE_PREPARE_NORMALIZE 0x02 4085 #define SQLITE_PREPARE_NO_VTAB 0x04 4086 4087 /* 4088 ** CAPI3REF: Compiling An SQL Statement 4089 ** KEYWORDS: {SQL statement compiler} 4090 ** METHOD: sqlite3 4091 ** CONSTRUCTOR: sqlite3_stmt 4092 ** 4093 ** To execute an SQL statement, it must first be compiled into a byte-code 4094 ** program using one of these routines. Or, in other words, these routines 4095 ** are constructors for the [prepared statement] object. 4096 ** 4097 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 4098 ** [sqlite3_prepare()] interface is legacy and should be avoided. 4099 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4100 ** for special purposes. 4101 ** 4102 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 4103 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 4104 ** as a convenience. The UTF-16 interfaces work by converting the 4105 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4106 ** 4107 ** The first argument, "db", is a [database connection] obtained from a 4108 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4109 ** [sqlite3_open16()]. The database connection must not have been closed. 4110 ** 4111 ** The second argument, "zSql", is the statement to be compiled, encoded 4112 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4113 ** and sqlite3_prepare_v3() 4114 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4115 ** and sqlite3_prepare16_v3() use UTF-16. 4116 ** 4117 ** ^If the nByte argument is negative, then zSql is read up to the 4118 ** first zero terminator. ^If nByte is positive, then it is the 4119 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 4120 ** statement is generated. 4121 ** If the caller knows that the supplied string is nul-terminated, then 4122 ** there is a small performance advantage to passing an nByte parameter that 4123 ** is the number of bytes in the input string <i>including</i> 4124 ** the nul-terminator. 4125 ** 4126 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4127 ** past the end of the first SQL statement in zSql. These routines only 4128 ** compile the first statement in zSql, so *pzTail is left pointing to 4129 ** what remains uncompiled. 4130 ** 4131 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4132 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4133 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4134 ** string or a comment) then *ppStmt is set to NULL. 4135 ** The calling procedure is responsible for deleting the compiled 4136 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4137 ** ppStmt may not be NULL. 4138 ** 4139 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4140 ** otherwise an [error code] is returned. 4141 ** 4142 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4143 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4144 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4145 ** are retained for backwards compatibility, but their use is discouraged. 4146 ** ^In the "vX" interfaces, the prepared statement 4147 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4148 ** original SQL text. This causes the [sqlite3_step()] interface to 4149 ** behave differently in three ways: 4150 ** 4151 ** <ol> 4152 ** <li> 4153 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4154 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4155 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4156 ** retries will occur before sqlite3_step() gives up and returns an error. 4157 ** </li> 4158 ** 4159 ** <li> 4160 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4161 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4162 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4163 ** and the application would have to make a second call to [sqlite3_reset()] 4164 ** in order to find the underlying cause of the problem. With the "v2" prepare 4165 ** interfaces, the underlying reason for the error is returned immediately. 4166 ** </li> 4167 ** 4168 ** <li> 4169 ** ^If the specific value bound to a [parameter | host parameter] in the 4170 ** WHERE clause might influence the choice of query plan for a statement, 4171 ** then the statement will be automatically recompiled, as if there had been 4172 ** a schema change, on the first [sqlite3_step()] call following any change 4173 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4174 ** ^The specific value of a WHERE-clause [parameter] might influence the 4175 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4176 ** or [GLOB] operator or if the parameter is compared to an indexed column 4177 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4178 ** </li> 4179 ** </ol> 4180 ** 4181 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4182 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4183 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4184 ** sqlite3_prepare_v2() interface works exactly the same as 4185 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4186 */ 4187 SQLITE_API int sqlite3_prepare( 4188 sqlite3 *db, /* Database handle */ 4189 const char *zSql, /* SQL statement, UTF-8 encoded */ 4190 int nByte, /* Maximum length of zSql in bytes. */ 4191 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4192 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4193 ); 4194 SQLITE_API int sqlite3_prepare_v2( 4195 sqlite3 *db, /* Database handle */ 4196 const char *zSql, /* SQL statement, UTF-8 encoded */ 4197 int nByte, /* Maximum length of zSql in bytes. */ 4198 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4199 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4200 ); 4201 SQLITE_API int sqlite3_prepare_v3( 4202 sqlite3 *db, /* Database handle */ 4203 const char *zSql, /* SQL statement, UTF-8 encoded */ 4204 int nByte, /* Maximum length of zSql in bytes. */ 4205 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4206 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4207 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4208 ); 4209 SQLITE_API int sqlite3_prepare16( 4210 sqlite3 *db, /* Database handle */ 4211 const void *zSql, /* SQL statement, UTF-16 encoded */ 4212 int nByte, /* Maximum length of zSql in bytes. */ 4213 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4214 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4215 ); 4216 SQLITE_API int sqlite3_prepare16_v2( 4217 sqlite3 *db, /* Database handle */ 4218 const void *zSql, /* SQL statement, UTF-16 encoded */ 4219 int nByte, /* Maximum length of zSql in bytes. */ 4220 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4221 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4222 ); 4223 SQLITE_API int sqlite3_prepare16_v3( 4224 sqlite3 *db, /* Database handle */ 4225 const void *zSql, /* SQL statement, UTF-16 encoded */ 4226 int nByte, /* Maximum length of zSql in bytes. */ 4227 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4228 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4229 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4230 ); 4231 4232 /* 4233 ** CAPI3REF: Retrieving Statement SQL 4234 ** METHOD: sqlite3_stmt 4235 ** 4236 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4237 ** SQL text used to create [prepared statement] P if P was 4238 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4239 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4240 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4241 ** string containing the SQL text of prepared statement P with 4242 ** [bound parameters] expanded. 4243 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4244 ** string containing the normalized SQL text of prepared statement P. The 4245 ** semantics used to normalize a SQL statement are unspecified and subject 4246 ** to change. At a minimum, literal values will be replaced with suitable 4247 ** placeholders. 4248 ** 4249 ** ^(For example, if a prepared statement is created using the SQL 4250 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4251 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4252 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4253 ** will return "SELECT 2345,NULL".)^ 4254 ** 4255 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4256 ** is available to hold the result, or if the result would exceed the 4257 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4258 ** 4259 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4260 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4261 ** option causes sqlite3_expanded_sql() to always return NULL. 4262 ** 4263 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4264 ** are managed by SQLite and are automatically freed when the prepared 4265 ** statement is finalized. 4266 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4267 ** is obtained from [sqlite3_malloc()] and must be freed by the application 4268 ** by passing it to [sqlite3_free()]. 4269 ** 4270 ** ^The sqlite3_normalized_sql() interface is only available if 4271 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4272 */ 4273 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4274 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4275 #ifdef SQLITE_ENABLE_NORMALIZE 4276 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4277 #endif 4278 4279 /* 4280 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4281 ** METHOD: sqlite3_stmt 4282 ** 4283 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4284 ** and only if the [prepared statement] X makes no direct changes to 4285 ** the content of the database file. 4286 ** 4287 ** Note that [application-defined SQL functions] or 4288 ** [virtual tables] might change the database indirectly as a side effect. 4289 ** ^(For example, if an application defines a function "eval()" that 4290 ** calls [sqlite3_exec()], then the following SQL statement would 4291 ** change the database file through side-effects: 4292 ** 4293 ** <blockquote><pre> 4294 ** SELECT eval('DELETE FROM t1') FROM t2; 4295 ** </pre></blockquote> 4296 ** 4297 ** But because the [SELECT] statement does not change the database file 4298 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4299 ** 4300 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4301 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4302 ** since the statements themselves do not actually modify the database but 4303 ** rather they control the timing of when other statements modify the 4304 ** database. ^The [ATTACH] and [DETACH] statements also cause 4305 ** sqlite3_stmt_readonly() to return true since, while those statements 4306 ** change the configuration of a database connection, they do not make 4307 ** changes to the content of the database files on disk. 4308 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4309 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4310 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4311 ** sqlite3_stmt_readonly() returns false for those commands. 4312 ** 4313 ** ^This routine returns false if there is any possibility that the 4314 ** statement might change the database file. ^A false return does 4315 ** not guarantee that the statement will change the database file. 4316 ** ^For example, an UPDATE statement might have a WHERE clause that 4317 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4318 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4319 ** read-only no-op if the table already exists, but 4320 ** sqlite3_stmt_readonly() still returns false for such a statement. 4321 ** 4322 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4323 ** statement, then sqlite3_stmt_readonly(X) returns the same value as 4324 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4325 */ 4326 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4327 4328 /* 4329 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4330 ** METHOD: sqlite3_stmt 4331 ** 4332 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4333 ** prepared statement S is an EXPLAIN statement, or 2 if the 4334 ** statement S is an EXPLAIN QUERY PLAN. 4335 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4336 ** an ordinary statement or a NULL pointer. 4337 */ 4338 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4339 4340 /* 4341 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4342 ** METHOD: sqlite3_stmt 4343 ** 4344 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4345 ** [prepared statement] S has been stepped at least once using 4346 ** [sqlite3_step(S)] but has neither run to completion (returned 4347 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4348 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4349 ** interface returns false if S is a NULL pointer. If S is not a 4350 ** NULL pointer and is not a pointer to a valid [prepared statement] 4351 ** object, then the behavior is undefined and probably undesirable. 4352 ** 4353 ** This interface can be used in combination [sqlite3_next_stmt()] 4354 ** to locate all prepared statements associated with a database 4355 ** connection that are in need of being reset. This can be used, 4356 ** for example, in diagnostic routines to search for prepared 4357 ** statements that are holding a transaction open. 4358 */ 4359 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4360 4361 /* 4362 ** CAPI3REF: Dynamically Typed Value Object 4363 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4364 ** 4365 ** SQLite uses the sqlite3_value object to represent all values 4366 ** that can be stored in a database table. SQLite uses dynamic typing 4367 ** for the values it stores. ^Values stored in sqlite3_value objects 4368 ** can be integers, floating point values, strings, BLOBs, or NULL. 4369 ** 4370 ** An sqlite3_value object may be either "protected" or "unprotected". 4371 ** Some interfaces require a protected sqlite3_value. Other interfaces 4372 ** will accept either a protected or an unprotected sqlite3_value. 4373 ** Every interface that accepts sqlite3_value arguments specifies 4374 ** whether or not it requires a protected sqlite3_value. The 4375 ** [sqlite3_value_dup()] interface can be used to construct a new 4376 ** protected sqlite3_value from an unprotected sqlite3_value. 4377 ** 4378 ** The terms "protected" and "unprotected" refer to whether or not 4379 ** a mutex is held. An internal mutex is held for a protected 4380 ** sqlite3_value object but no mutex is held for an unprotected 4381 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4382 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4383 ** or if SQLite is run in one of reduced mutex modes 4384 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4385 ** then there is no distinction between protected and unprotected 4386 ** sqlite3_value objects and they can be used interchangeably. However, 4387 ** for maximum code portability it is recommended that applications 4388 ** still make the distinction between protected and unprotected 4389 ** sqlite3_value objects even when not strictly required. 4390 ** 4391 ** ^The sqlite3_value objects that are passed as parameters into the 4392 ** implementation of [application-defined SQL functions] are protected. 4393 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4394 ** are protected. 4395 ** ^The sqlite3_value object returned by 4396 ** [sqlite3_column_value()] is unprotected. 4397 ** Unprotected sqlite3_value objects may only be used as arguments 4398 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4399 ** [sqlite3_value_dup()]. 4400 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4401 ** interfaces require protected sqlite3_value objects. 4402 */ 4403 typedef struct sqlite3_value sqlite3_value; 4404 4405 /* 4406 ** CAPI3REF: SQL Function Context Object 4407 ** 4408 ** The context in which an SQL function executes is stored in an 4409 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4410 ** is always first parameter to [application-defined SQL functions]. 4411 ** The application-defined SQL function implementation will pass this 4412 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4413 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4414 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4415 ** and/or [sqlite3_set_auxdata()]. 4416 */ 4417 typedef struct sqlite3_context sqlite3_context; 4418 4419 /* 4420 ** CAPI3REF: Binding Values To Prepared Statements 4421 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4422 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4423 ** METHOD: sqlite3_stmt 4424 ** 4425 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4426 ** literals may be replaced by a [parameter] that matches one of following 4427 ** templates: 4428 ** 4429 ** <ul> 4430 ** <li> ? 4431 ** <li> ?NNN 4432 ** <li> :VVV 4433 ** <li> @VVV 4434 ** <li> $VVV 4435 ** </ul> 4436 ** 4437 ** In the templates above, NNN represents an integer literal, 4438 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4439 ** parameters (also called "host parameter names" or "SQL parameters") 4440 ** can be set using the sqlite3_bind_*() routines defined here. 4441 ** 4442 ** ^The first argument to the sqlite3_bind_*() routines is always 4443 ** a pointer to the [sqlite3_stmt] object returned from 4444 ** [sqlite3_prepare_v2()] or its variants. 4445 ** 4446 ** ^The second argument is the index of the SQL parameter to be set. 4447 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4448 ** SQL parameter is used more than once, second and subsequent 4449 ** occurrences have the same index as the first occurrence. 4450 ** ^The index for named parameters can be looked up using the 4451 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4452 ** for "?NNN" parameters is the value of NNN. 4453 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4454 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4455 ** 4456 ** ^The third argument is the value to bind to the parameter. 4457 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4458 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4459 ** is ignored and the end result is the same as sqlite3_bind_null(). 4460 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4461 ** it should be a pointer to well-formed UTF8 text. 4462 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4463 ** it should be a pointer to well-formed UTF16 text. 4464 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4465 ** it should be a pointer to a well-formed unicode string that is 4466 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4467 ** otherwise. 4468 ** 4469 ** [[byte-order determination rules]] ^The byte-order of 4470 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4471 ** found in first character, which is removed, or in the absence of a BOM 4472 ** the byte order is the native byte order of the host 4473 ** machine for sqlite3_bind_text16() or the byte order specified in 4474 ** the 6th parameter for sqlite3_bind_text64().)^ 4475 ** ^If UTF16 input text contains invalid unicode 4476 ** characters, then SQLite might change those invalid characters 4477 ** into the unicode replacement character: U+FFFD. 4478 ** 4479 ** ^(In those routines that have a fourth argument, its value is the 4480 ** number of bytes in the parameter. To be clear: the value is the 4481 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4482 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4483 ** is negative, then the length of the string is 4484 ** the number of bytes up to the first zero terminator. 4485 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4486 ** the behavior is undefined. 4487 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4488 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4489 ** that parameter must be the byte offset 4490 ** where the NUL terminator would occur assuming the string were NUL 4491 ** terminated. If any NUL characters occurs at byte offsets less than 4492 ** the value of the fourth parameter then the resulting string value will 4493 ** contain embedded NULs. The result of expressions involving strings 4494 ** with embedded NULs is undefined. 4495 ** 4496 ** ^The fifth argument to the BLOB and string binding interfaces controls 4497 ** or indicates the lifetime of the object referenced by the third parameter. 4498 ** These three options exist: 4499 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4500 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4501 ** if the call to the bind API fails, except the destructor is not called if 4502 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4503 ** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that 4504 ** the application remains responsible for disposing of the object. ^In this 4505 ** case, the object and the provided pointer to it must remain valid until 4506 ** either the prepared statement is finalized or the same SQL parameter is 4507 ** bound to something else, whichever occurs sooner. 4508 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4509 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4510 ** object and pointer to it must remain valid until then. ^SQLite will then 4511 ** manage the lifetime of its private copy. 4512 ** 4513 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4514 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4515 ** to specify the encoding of the text in the third parameter. If 4516 ** the sixth argument to sqlite3_bind_text64() is not one of the 4517 ** allowed values shown above, or if the text encoding is different 4518 ** from the encoding specified by the sixth parameter, then the behavior 4519 ** is undefined. 4520 ** 4521 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4522 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4523 ** (just an integer to hold its size) while it is being processed. 4524 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4525 ** content is later written using 4526 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4527 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4528 ** 4529 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4530 ** [prepared statement] S to have an SQL value of NULL, but to also be 4531 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4532 ** a pointer to a destructor function for P. ^SQLite will invoke the 4533 ** destructor D with a single argument of P when it is finished using 4534 ** P. The T parameter should be a static string, preferably a string 4535 ** literal. The sqlite3_bind_pointer() routine is part of the 4536 ** [pointer passing interface] added for SQLite 3.20.0. 4537 ** 4538 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4539 ** for the [prepared statement] or with a prepared statement for which 4540 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4541 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4542 ** routine is passed a [prepared statement] that has been finalized, the 4543 ** result is undefined and probably harmful. 4544 ** 4545 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4546 ** ^Unbound parameters are interpreted as NULL. 4547 ** 4548 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4549 ** [error code] if anything goes wrong. 4550 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4551 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4552 ** [SQLITE_MAX_LENGTH]. 4553 ** ^[SQLITE_RANGE] is returned if the parameter 4554 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4555 ** 4556 ** See also: [sqlite3_bind_parameter_count()], 4557 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4558 */ 4559 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4560 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4561 void(*)(void*)); 4562 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4563 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4564 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4565 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4566 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4567 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4568 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4569 void(*)(void*), unsigned char encoding); 4570 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4571 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4572 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4573 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4574 4575 /* 4576 ** CAPI3REF: Number Of SQL Parameters 4577 ** METHOD: sqlite3_stmt 4578 ** 4579 ** ^This routine can be used to find the number of [SQL parameters] 4580 ** in a [prepared statement]. SQL parameters are tokens of the 4581 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4582 ** placeholders for values that are [sqlite3_bind_blob | bound] 4583 ** to the parameters at a later time. 4584 ** 4585 ** ^(This routine actually returns the index of the largest (rightmost) 4586 ** parameter. For all forms except ?NNN, this will correspond to the 4587 ** number of unique parameters. If parameters of the ?NNN form are used, 4588 ** there may be gaps in the list.)^ 4589 ** 4590 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4591 ** [sqlite3_bind_parameter_name()], and 4592 ** [sqlite3_bind_parameter_index()]. 4593 */ 4594 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4595 4596 /* 4597 ** CAPI3REF: Name Of A Host Parameter 4598 ** METHOD: sqlite3_stmt 4599 ** 4600 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4601 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4602 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4603 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4604 ** respectively. 4605 ** In other words, the initial ":" or "$" or "@" or "?" 4606 ** is included as part of the name.)^ 4607 ** ^Parameters of the form "?" without a following integer have no name 4608 ** and are referred to as "nameless" or "anonymous parameters". 4609 ** 4610 ** ^The first host parameter has an index of 1, not 0. 4611 ** 4612 ** ^If the value N is out of range or if the N-th parameter is 4613 ** nameless, then NULL is returned. ^The returned string is 4614 ** always in UTF-8 encoding even if the named parameter was 4615 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4616 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4617 ** 4618 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4619 ** [sqlite3_bind_parameter_count()], and 4620 ** [sqlite3_bind_parameter_index()]. 4621 */ 4622 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4623 4624 /* 4625 ** CAPI3REF: Index Of A Parameter With A Given Name 4626 ** METHOD: sqlite3_stmt 4627 ** 4628 ** ^Return the index of an SQL parameter given its name. ^The 4629 ** index value returned is suitable for use as the second 4630 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4631 ** is returned if no matching parameter is found. ^The parameter 4632 ** name must be given in UTF-8 even if the original statement 4633 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4634 ** [sqlite3_prepare16_v3()]. 4635 ** 4636 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4637 ** [sqlite3_bind_parameter_count()], and 4638 ** [sqlite3_bind_parameter_name()]. 4639 */ 4640 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4641 4642 /* 4643 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4644 ** METHOD: sqlite3_stmt 4645 ** 4646 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4647 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4648 ** ^Use this routine to reset all host parameters to NULL. 4649 */ 4650 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4651 4652 /* 4653 ** CAPI3REF: Number Of Columns In A Result Set 4654 ** METHOD: sqlite3_stmt 4655 ** 4656 ** ^Return the number of columns in the result set returned by the 4657 ** [prepared statement]. ^If this routine returns 0, that means the 4658 ** [prepared statement] returns no data (for example an [UPDATE]). 4659 ** ^However, just because this routine returns a positive number does not 4660 ** mean that one or more rows of data will be returned. ^A SELECT statement 4661 ** will always have a positive sqlite3_column_count() but depending on the 4662 ** WHERE clause constraints and the table content, it might return no rows. 4663 ** 4664 ** See also: [sqlite3_data_count()] 4665 */ 4666 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4667 4668 /* 4669 ** CAPI3REF: Column Names In A Result Set 4670 ** METHOD: sqlite3_stmt 4671 ** 4672 ** ^These routines return the name assigned to a particular column 4673 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4674 ** interface returns a pointer to a zero-terminated UTF-8 string 4675 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4676 ** UTF-16 string. ^The first parameter is the [prepared statement] 4677 ** that implements the [SELECT] statement. ^The second parameter is the 4678 ** column number. ^The leftmost column is number 0. 4679 ** 4680 ** ^The returned string pointer is valid until either the [prepared statement] 4681 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4682 ** reprepared by the first call to [sqlite3_step()] for a particular run 4683 ** or until the next call to 4684 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4685 ** 4686 ** ^If sqlite3_malloc() fails during the processing of either routine 4687 ** (for example during a conversion from UTF-8 to UTF-16) then a 4688 ** NULL pointer is returned. 4689 ** 4690 ** ^The name of a result column is the value of the "AS" clause for 4691 ** that column, if there is an AS clause. If there is no AS clause 4692 ** then the name of the column is unspecified and may change from 4693 ** one release of SQLite to the next. 4694 */ 4695 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4696 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4697 4698 /* 4699 ** CAPI3REF: Source Of Data In A Query Result 4700 ** METHOD: sqlite3_stmt 4701 ** 4702 ** ^These routines provide a means to determine the database, table, and 4703 ** table column that is the origin of a particular result column in 4704 ** [SELECT] statement. 4705 ** ^The name of the database or table or column can be returned as 4706 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4707 ** the database name, the _table_ routines return the table name, and 4708 ** the origin_ routines return the column name. 4709 ** ^The returned string is valid until the [prepared statement] is destroyed 4710 ** using [sqlite3_finalize()] or until the statement is automatically 4711 ** reprepared by the first call to [sqlite3_step()] for a particular run 4712 ** or until the same information is requested 4713 ** again in a different encoding. 4714 ** 4715 ** ^The names returned are the original un-aliased names of the 4716 ** database, table, and column. 4717 ** 4718 ** ^The first argument to these interfaces is a [prepared statement]. 4719 ** ^These functions return information about the Nth result column returned by 4720 ** the statement, where N is the second function argument. 4721 ** ^The left-most column is column 0 for these routines. 4722 ** 4723 ** ^If the Nth column returned by the statement is an expression or 4724 ** subquery and is not a column value, then all of these functions return 4725 ** NULL. ^These routines might also return NULL if a memory allocation error 4726 ** occurs. ^Otherwise, they return the name of the attached database, table, 4727 ** or column that query result column was extracted from. 4728 ** 4729 ** ^As with all other SQLite APIs, those whose names end with "16" return 4730 ** UTF-16 encoded strings and the other functions return UTF-8. 4731 ** 4732 ** ^These APIs are only available if the library was compiled with the 4733 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4734 ** 4735 ** If two or more threads call one or more 4736 ** [sqlite3_column_database_name | column metadata interfaces] 4737 ** for the same [prepared statement] and result column 4738 ** at the same time then the results are undefined. 4739 */ 4740 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4741 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4742 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4743 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4744 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4745 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4746 4747 /* 4748 ** CAPI3REF: Declared Datatype Of A Query Result 4749 ** METHOD: sqlite3_stmt 4750 ** 4751 ** ^(The first parameter is a [prepared statement]. 4752 ** If this statement is a [SELECT] statement and the Nth column of the 4753 ** returned result set of that [SELECT] is a table column (not an 4754 ** expression or subquery) then the declared type of the table 4755 ** column is returned.)^ ^If the Nth column of the result set is an 4756 ** expression or subquery, then a NULL pointer is returned. 4757 ** ^The returned string is always UTF-8 encoded. 4758 ** 4759 ** ^(For example, given the database schema: 4760 ** 4761 ** CREATE TABLE t1(c1 VARIANT); 4762 ** 4763 ** and the following statement to be compiled: 4764 ** 4765 ** SELECT c1 + 1, c1 FROM t1; 4766 ** 4767 ** this routine would return the string "VARIANT" for the second result 4768 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4769 ** 4770 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4771 ** is declared to contain a particular type does not mean that the 4772 ** data stored in that column is of the declared type. SQLite is 4773 ** strongly typed, but the typing is dynamic not static. ^Type 4774 ** is associated with individual values, not with the containers 4775 ** used to hold those values. 4776 */ 4777 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4778 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4779 4780 /* 4781 ** CAPI3REF: Evaluate An SQL Statement 4782 ** METHOD: sqlite3_stmt 4783 ** 4784 ** After a [prepared statement] has been prepared using any of 4785 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4786 ** or [sqlite3_prepare16_v3()] or one of the legacy 4787 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4788 ** must be called one or more times to evaluate the statement. 4789 ** 4790 ** The details of the behavior of the sqlite3_step() interface depend 4791 ** on whether the statement was prepared using the newer "vX" interfaces 4792 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4793 ** [sqlite3_prepare16_v2()] or the older legacy 4794 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4795 ** new "vX" interface is recommended for new applications but the legacy 4796 ** interface will continue to be supported. 4797 ** 4798 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4799 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4800 ** ^With the "v2" interface, any of the other [result codes] or 4801 ** [extended result codes] might be returned as well. 4802 ** 4803 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4804 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4805 ** or occurs outside of an explicit transaction, then you can retry the 4806 ** statement. If the statement is not a [COMMIT] and occurs within an 4807 ** explicit transaction then you should rollback the transaction before 4808 ** continuing. 4809 ** 4810 ** ^[SQLITE_DONE] means that the statement has finished executing 4811 ** successfully. sqlite3_step() should not be called again on this virtual 4812 ** machine without first calling [sqlite3_reset()] to reset the virtual 4813 ** machine back to its initial state. 4814 ** 4815 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4816 ** is returned each time a new row of data is ready for processing by the 4817 ** caller. The values may be accessed using the [column access functions]. 4818 ** sqlite3_step() is called again to retrieve the next row of data. 4819 ** 4820 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4821 ** violation) has occurred. sqlite3_step() should not be called again on 4822 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4823 ** ^With the legacy interface, a more specific error code (for example, 4824 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4825 ** can be obtained by calling [sqlite3_reset()] on the 4826 ** [prepared statement]. ^In the "v2" interface, 4827 ** the more specific error code is returned directly by sqlite3_step(). 4828 ** 4829 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4830 ** Perhaps it was called on a [prepared statement] that has 4831 ** already been [sqlite3_finalize | finalized] or on one that had 4832 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4833 ** be the case that the same database connection is being used by two or 4834 ** more threads at the same moment in time. 4835 ** 4836 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4837 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4838 ** other than [SQLITE_ROW] before any subsequent invocation of 4839 ** sqlite3_step(). Failure to reset the prepared statement using 4840 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4841 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4842 ** sqlite3_step() began 4843 ** calling [sqlite3_reset()] automatically in this circumstance rather 4844 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4845 ** break because any application that ever receives an SQLITE_MISUSE error 4846 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4847 ** can be used to restore the legacy behavior. 4848 ** 4849 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4850 ** API always returns a generic error code, [SQLITE_ERROR], following any 4851 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4852 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4853 ** specific [error codes] that better describes the error. 4854 ** We admit that this is a goofy design. The problem has been fixed 4855 ** with the "v2" interface. If you prepare all of your SQL statements 4856 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4857 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4858 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4859 ** then the more specific [error codes] are returned directly 4860 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4861 */ 4862 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4863 4864 /* 4865 ** CAPI3REF: Number of columns in a result set 4866 ** METHOD: sqlite3_stmt 4867 ** 4868 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4869 ** current row of the result set of [prepared statement] P. 4870 ** ^If prepared statement P does not have results ready to return 4871 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4872 ** interfaces) then sqlite3_data_count(P) returns 0. 4873 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4874 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4875 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4876 ** will return non-zero if previous call to [sqlite3_step](P) returned 4877 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4878 ** where it always returns zero since each step of that multi-step 4879 ** pragma returns 0 columns of data. 4880 ** 4881 ** See also: [sqlite3_column_count()] 4882 */ 4883 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4884 4885 /* 4886 ** CAPI3REF: Fundamental Datatypes 4887 ** KEYWORDS: SQLITE_TEXT 4888 ** 4889 ** ^(Every value in SQLite has one of five fundamental datatypes: 4890 ** 4891 ** <ul> 4892 ** <li> 64-bit signed integer 4893 ** <li> 64-bit IEEE floating point number 4894 ** <li> string 4895 ** <li> BLOB 4896 ** <li> NULL 4897 ** </ul>)^ 4898 ** 4899 ** These constants are codes for each of those types. 4900 ** 4901 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4902 ** for a completely different meaning. Software that links against both 4903 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4904 ** SQLITE_TEXT. 4905 */ 4906 #define SQLITE_INTEGER 1 4907 #define SQLITE_FLOAT 2 4908 #define SQLITE_BLOB 4 4909 #define SQLITE_NULL 5 4910 #ifdef SQLITE_TEXT 4911 # undef SQLITE_TEXT 4912 #else 4913 # define SQLITE_TEXT 3 4914 #endif 4915 #define SQLITE3_TEXT 3 4916 4917 /* 4918 ** CAPI3REF: Result Values From A Query 4919 ** KEYWORDS: {column access functions} 4920 ** METHOD: sqlite3_stmt 4921 ** 4922 ** <b>Summary:</b> 4923 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4924 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4925 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4926 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4927 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4928 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4929 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4930 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4931 ** [sqlite3_value|unprotected sqlite3_value] object. 4932 ** <tr><td> <td> <td> 4933 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4934 ** or a UTF-8 TEXT result in bytes 4935 ** <tr><td><b>sqlite3_column_bytes16 </b> 4936 ** <td>→ <td>Size of UTF-16 4937 ** TEXT in bytes 4938 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4939 ** datatype of the result 4940 ** </table></blockquote> 4941 ** 4942 ** <b>Details:</b> 4943 ** 4944 ** ^These routines return information about a single column of the current 4945 ** result row of a query. ^In every case the first argument is a pointer 4946 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4947 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4948 ** and the second argument is the index of the column for which information 4949 ** should be returned. ^The leftmost column of the result set has the index 0. 4950 ** ^The number of columns in the result can be determined using 4951 ** [sqlite3_column_count()]. 4952 ** 4953 ** If the SQL statement does not currently point to a valid row, or if the 4954 ** column index is out of range, the result is undefined. 4955 ** These routines may only be called when the most recent call to 4956 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4957 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4958 ** If any of these routines are called after [sqlite3_reset()] or 4959 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4960 ** something other than [SQLITE_ROW], the results are undefined. 4961 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4962 ** are called from a different thread while any of these routines 4963 ** are pending, then the results are undefined. 4964 ** 4965 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4966 ** each return the value of a result column in a specific data format. If 4967 ** the result column is not initially in the requested format (for example, 4968 ** if the query returns an integer but the sqlite3_column_text() interface 4969 ** is used to extract the value) then an automatic type conversion is performed. 4970 ** 4971 ** ^The sqlite3_column_type() routine returns the 4972 ** [SQLITE_INTEGER | datatype code] for the initial data type 4973 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4974 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4975 ** The return value of sqlite3_column_type() can be used to decide which 4976 ** of the first six interface should be used to extract the column value. 4977 ** The value returned by sqlite3_column_type() is only meaningful if no 4978 ** automatic type conversions have occurred for the value in question. 4979 ** After a type conversion, the result of calling sqlite3_column_type() 4980 ** is undefined, though harmless. Future 4981 ** versions of SQLite may change the behavior of sqlite3_column_type() 4982 ** following a type conversion. 4983 ** 4984 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4985 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4986 ** of that BLOB or string. 4987 ** 4988 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4989 ** routine returns the number of bytes in that BLOB or string. 4990 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4991 ** the string to UTF-8 and then returns the number of bytes. 4992 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4993 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4994 ** the number of bytes in that string. 4995 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4996 ** 4997 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4998 ** routine returns the number of bytes in that BLOB or string. 4999 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 5000 ** the string to UTF-16 and then returns the number of bytes. 5001 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 5002 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 5003 ** the number of bytes in that string. 5004 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 5005 ** 5006 ** ^The values returned by [sqlite3_column_bytes()] and 5007 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 5008 ** of the string. ^For clarity: the values returned by 5009 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 5010 ** bytes in the string, not the number of characters. 5011 ** 5012 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 5013 ** even empty strings, are always zero-terminated. ^The return 5014 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 5015 ** 5016 ** ^Strings returned by sqlite3_column_text16() always have the endianness 5017 ** which is native to the platform, regardless of the text encoding set 5018 ** for the database. 5019 ** 5020 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 5021 ** [unprotected sqlite3_value] object. In a multithreaded environment, 5022 ** an unprotected sqlite3_value object may only be used safely with 5023 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 5024 ** If the [unprotected sqlite3_value] object returned by 5025 ** [sqlite3_column_value()] is used in any other way, including calls 5026 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 5027 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 5028 ** Hence, the sqlite3_column_value() interface 5029 ** is normally only useful within the implementation of 5030 ** [application-defined SQL functions] or [virtual tables], not within 5031 ** top-level application code. 5032 ** 5033 ** These routines may attempt to convert the datatype of the result. 5034 ** ^For example, if the internal representation is FLOAT and a text result 5035 ** is requested, [sqlite3_snprintf()] is used internally to perform the 5036 ** conversion automatically. ^(The following table details the conversions 5037 ** that are applied: 5038 ** 5039 ** <blockquote> 5040 ** <table border="1"> 5041 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5042 ** 5043 ** <tr><td> NULL <td> INTEGER <td> Result is 0 5044 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5045 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5046 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5047 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5048 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5049 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5050 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5051 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5052 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5053 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5054 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5055 ** <tr><td> TEXT <td> BLOB <td> No change 5056 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5057 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5058 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5059 ** </table> 5060 ** </blockquote>)^ 5061 ** 5062 ** Note that when type conversions occur, pointers returned by prior 5063 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5064 ** sqlite3_column_text16() may be invalidated. 5065 ** Type conversions and pointer invalidations might occur 5066 ** in the following cases: 5067 ** 5068 ** <ul> 5069 ** <li> The initial content is a BLOB and sqlite3_column_text() or 5070 ** sqlite3_column_text16() is called. A zero-terminator might 5071 ** need to be added to the string.</li> 5072 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5073 ** sqlite3_column_text16() is called. The content must be converted 5074 ** to UTF-16.</li> 5075 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5076 ** sqlite3_column_text() is called. The content must be converted 5077 ** to UTF-8.</li> 5078 ** </ul> 5079 ** 5080 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5081 ** not invalidate a prior pointer, though of course the content of the buffer 5082 ** that the prior pointer references will have been modified. Other kinds 5083 ** of conversion are done in place when it is possible, but sometimes they 5084 ** are not possible and in those cases prior pointers are invalidated. 5085 ** 5086 ** The safest policy is to invoke these routines 5087 ** in one of the following ways: 5088 ** 5089 ** <ul> 5090 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5091 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5092 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5093 ** </ul> 5094 ** 5095 ** In other words, you should call sqlite3_column_text(), 5096 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5097 ** into the desired format, then invoke sqlite3_column_bytes() or 5098 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5099 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5100 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5101 ** with calls to sqlite3_column_bytes(). 5102 ** 5103 ** ^The pointers returned are valid until a type conversion occurs as 5104 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5105 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5106 ** and BLOBs is freed automatically. Do not pass the pointers returned 5107 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5108 ** [sqlite3_free()]. 5109 ** 5110 ** As long as the input parameters are correct, these routines will only 5111 ** fail if an out-of-memory error occurs during a format conversion. 5112 ** Only the following subset of interfaces are subject to out-of-memory 5113 ** errors: 5114 ** 5115 ** <ul> 5116 ** <li> sqlite3_column_blob() 5117 ** <li> sqlite3_column_text() 5118 ** <li> sqlite3_column_text16() 5119 ** <li> sqlite3_column_bytes() 5120 ** <li> sqlite3_column_bytes16() 5121 ** </ul> 5122 ** 5123 ** If an out-of-memory error occurs, then the return value from these 5124 ** routines is the same as if the column had contained an SQL NULL value. 5125 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5126 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5127 ** return value is obtained and before any 5128 ** other SQLite interface is called on the same [database connection]. 5129 */ 5130 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5131 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5132 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5133 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5134 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5135 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5136 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5137 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5138 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5139 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5140 5141 /* 5142 ** CAPI3REF: Destroy A Prepared Statement Object 5143 ** DESTRUCTOR: sqlite3_stmt 5144 ** 5145 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5146 ** ^If the most recent evaluation of the statement encountered no errors 5147 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 5148 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5149 ** sqlite3_finalize(S) returns the appropriate [error code] or 5150 ** [extended error code]. 5151 ** 5152 ** ^The sqlite3_finalize(S) routine can be called at any point during 5153 ** the life cycle of [prepared statement] S: 5154 ** before statement S is ever evaluated, after 5155 ** one or more calls to [sqlite3_reset()], or after any call 5156 ** to [sqlite3_step()] regardless of whether or not the statement has 5157 ** completed execution. 5158 ** 5159 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5160 ** 5161 ** The application must finalize every [prepared statement] in order to avoid 5162 ** resource leaks. It is a grievous error for the application to try to use 5163 ** a prepared statement after it has been finalized. Any use of a prepared 5164 ** statement after it has been finalized can result in undefined and 5165 ** undesirable behavior such as segfaults and heap corruption. 5166 */ 5167 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5168 5169 /* 5170 ** CAPI3REF: Reset A Prepared Statement Object 5171 ** METHOD: sqlite3_stmt 5172 ** 5173 ** The sqlite3_reset() function is called to reset a [prepared statement] 5174 ** object back to its initial state, ready to be re-executed. 5175 ** ^Any SQL statement variables that had values bound to them using 5176 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5177 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5178 ** 5179 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5180 ** back to the beginning of its program. 5181 ** 5182 ** ^If the most recent call to [sqlite3_step(S)] for the 5183 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5184 ** or if [sqlite3_step(S)] has never before been called on S, 5185 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5186 ** 5187 ** ^If the most recent call to [sqlite3_step(S)] for the 5188 ** [prepared statement] S indicated an error, then 5189 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5190 ** 5191 ** ^The [sqlite3_reset(S)] interface does not change the values 5192 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5193 */ 5194 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5195 5196 /* 5197 ** CAPI3REF: Create Or Redefine SQL Functions 5198 ** KEYWORDS: {function creation routines} 5199 ** METHOD: sqlite3 5200 ** 5201 ** ^These functions (collectively known as "function creation routines") 5202 ** are used to add SQL functions or aggregates or to redefine the behavior 5203 ** of existing SQL functions or aggregates. The only differences between 5204 ** the three "sqlite3_create_function*" routines are the text encoding 5205 ** expected for the second parameter (the name of the function being 5206 ** created) and the presence or absence of a destructor callback for 5207 ** the application data pointer. Function sqlite3_create_window_function() 5208 ** is similar, but allows the user to supply the extra callback functions 5209 ** needed by [aggregate window functions]. 5210 ** 5211 ** ^The first parameter is the [database connection] to which the SQL 5212 ** function is to be added. ^If an application uses more than one database 5213 ** connection then application-defined SQL functions must be added 5214 ** to each database connection separately. 5215 ** 5216 ** ^The second parameter is the name of the SQL function to be created or 5217 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5218 ** representation, exclusive of the zero-terminator. ^Note that the name 5219 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5220 ** ^Any attempt to create a function with a longer name 5221 ** will result in [SQLITE_MISUSE] being returned. 5222 ** 5223 ** ^The third parameter (nArg) 5224 ** is the number of arguments that the SQL function or 5225 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5226 ** aggregate may take any number of arguments between 0 and the limit 5227 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5228 ** parameter is less than -1 or greater than 127 then the behavior is 5229 ** undefined. 5230 ** 5231 ** ^The fourth parameter, eTextRep, specifies what 5232 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5233 ** its parameters. The application should set this parameter to 5234 ** [SQLITE_UTF16LE] if the function implementation invokes 5235 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5236 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5237 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5238 ** otherwise. ^The same SQL function may be registered multiple times using 5239 ** different preferred text encodings, with different implementations for 5240 ** each encoding. 5241 ** ^When multiple implementations of the same function are available, SQLite 5242 ** will pick the one that involves the least amount of data conversion. 5243 ** 5244 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5245 ** to signal that the function will always return the same result given 5246 ** the same inputs within a single SQL statement. Most SQL functions are 5247 ** deterministic. The built-in [random()] SQL function is an example of a 5248 ** function that is not deterministic. The SQLite query planner is able to 5249 ** perform additional optimizations on deterministic functions, so use 5250 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5251 ** 5252 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5253 ** flag, which if present prevents the function from being invoked from 5254 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5255 ** index expressions, or the WHERE clause of partial indexes. 5256 ** 5257 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5258 ** all application-defined SQL functions that do not need to be 5259 ** used inside of triggers, view, CHECK constraints, or other elements of 5260 ** the database schema. This flags is especially recommended for SQL 5261 ** functions that have side effects or reveal internal application state. 5262 ** Without this flag, an attacker might be able to modify the schema of 5263 ** a database file to include invocations of the function with parameters 5264 ** chosen by the attacker, which the application will then execute when 5265 ** the database file is opened and read. 5266 ** 5267 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5268 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5269 ** 5270 ** ^The sixth, seventh and eighth parameters passed to the three 5271 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5272 ** pointers to C-language functions that implement the SQL function or 5273 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5274 ** callback only; NULL pointers must be passed as the xStep and xFinal 5275 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5276 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5277 ** SQL function or aggregate, pass NULL pointers for all three function 5278 ** callbacks. 5279 ** 5280 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5281 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5282 ** C-language callbacks that implement the new function. xStep and xFinal 5283 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5284 ** which case a regular aggregate function is created, or must both be 5285 ** non-NULL, in which case the new function may be used as either an aggregate 5286 ** or aggregate window function. More details regarding the implementation 5287 ** of aggregate window functions are 5288 ** [user-defined window functions|available here]. 5289 ** 5290 ** ^(If the final parameter to sqlite3_create_function_v2() or 5291 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5292 ** the application data pointer. The destructor is invoked when the function 5293 ** is deleted, either by being overloaded or when the database connection 5294 ** closes.)^ ^The destructor is also invoked if the call to 5295 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5296 ** invoked, it is passed a single argument which is a copy of the application 5297 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5298 ** 5299 ** ^It is permitted to register multiple implementations of the same 5300 ** functions with the same name but with either differing numbers of 5301 ** arguments or differing preferred text encodings. ^SQLite will use 5302 ** the implementation that most closely matches the way in which the 5303 ** SQL function is used. ^A function implementation with a non-negative 5304 ** nArg parameter is a better match than a function implementation with 5305 ** a negative nArg. ^A function where the preferred text encoding 5306 ** matches the database encoding is a better 5307 ** match than a function where the encoding is different. 5308 ** ^A function where the encoding difference is between UTF16le and UTF16be 5309 ** is a closer match than a function where the encoding difference is 5310 ** between UTF8 and UTF16. 5311 ** 5312 ** ^Built-in functions may be overloaded by new application-defined functions. 5313 ** 5314 ** ^An application-defined function is permitted to call other 5315 ** SQLite interfaces. However, such calls must not 5316 ** close the database connection nor finalize or reset the prepared 5317 ** statement in which the function is running. 5318 */ 5319 SQLITE_API int sqlite3_create_function( 5320 sqlite3 *db, 5321 const char *zFunctionName, 5322 int nArg, 5323 int eTextRep, 5324 void *pApp, 5325 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5326 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5327 void (*xFinal)(sqlite3_context*) 5328 ); 5329 SQLITE_API int sqlite3_create_function16( 5330 sqlite3 *db, 5331 const void *zFunctionName, 5332 int nArg, 5333 int eTextRep, 5334 void *pApp, 5335 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5336 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5337 void (*xFinal)(sqlite3_context*) 5338 ); 5339 SQLITE_API int sqlite3_create_function_v2( 5340 sqlite3 *db, 5341 const char *zFunctionName, 5342 int nArg, 5343 int eTextRep, 5344 void *pApp, 5345 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5346 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5347 void (*xFinal)(sqlite3_context*), 5348 void(*xDestroy)(void*) 5349 ); 5350 SQLITE_API int sqlite3_create_window_function( 5351 sqlite3 *db, 5352 const char *zFunctionName, 5353 int nArg, 5354 int eTextRep, 5355 void *pApp, 5356 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5357 void (*xFinal)(sqlite3_context*), 5358 void (*xValue)(sqlite3_context*), 5359 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5360 void(*xDestroy)(void*) 5361 ); 5362 5363 /* 5364 ** CAPI3REF: Text Encodings 5365 ** 5366 ** These constant define integer codes that represent the various 5367 ** text encodings supported by SQLite. 5368 */ 5369 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5370 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5371 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5372 #define SQLITE_UTF16 4 /* Use native byte order */ 5373 #define SQLITE_ANY 5 /* Deprecated */ 5374 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5375 5376 /* 5377 ** CAPI3REF: Function Flags 5378 ** 5379 ** These constants may be ORed together with the 5380 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5381 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5382 ** [sqlite3_create_function_v2()]. 5383 ** 5384 ** <dl> 5385 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5386 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5387 ** the same output when the input parameters are the same. 5388 ** The [abs|abs() function] is deterministic, for example, but 5389 ** [randomblob|randomblob()] is not. Functions must 5390 ** be deterministic in order to be used in certain contexts such as 5391 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5392 ** SQLite might also optimize deterministic functions by factoring them 5393 ** out of inner loops. 5394 ** </dd> 5395 ** 5396 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5397 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5398 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5399 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5400 ** [expression indexes], [partial indexes], or [generated columns]. 5401 ** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5402 ** for all [application-defined SQL functions], and especially for functions 5403 ** that have side-effects or that could potentially leak sensitive 5404 ** information. 5405 ** </dd> 5406 ** 5407 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5408 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5409 ** to cause problems even if misused. An innocuous function should have 5410 ** no side effects and should not depend on any values other than its 5411 ** input parameters. The [abs|abs() function] is an example of an 5412 ** innocuous function. 5413 ** The [load_extension() SQL function] is not innocuous because of its 5414 ** side effects. 5415 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5416 ** exactly the same. The [random|random() function] is an example of a 5417 ** function that is innocuous but not deterministic. 5418 ** <p>Some heightened security settings 5419 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5420 ** disable the use of SQL functions inside views and triggers and in 5421 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5422 ** [expression indexes], [partial indexes], and [generated columns] unless 5423 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5424 ** are innocuous. Developers are advised to avoid using the 5425 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5426 ** function has been carefully audited and found to be free of potentially 5427 ** security-adverse side-effects and information-leaks. 5428 ** </dd> 5429 ** 5430 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5431 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5432 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5433 ** Specifying this flag makes no difference for scalar or aggregate user 5434 ** functions. However, if it is not specified for a user-defined window 5435 ** function, then any sub-types belonging to arguments passed to the window 5436 ** function may be discarded before the window function is called (i.e. 5437 ** sqlite3_value_subtype() will always return 0). 5438 ** </dd> 5439 ** </dl> 5440 */ 5441 #define SQLITE_DETERMINISTIC 0x000000800 5442 #define SQLITE_DIRECTONLY 0x000080000 5443 #define SQLITE_SUBTYPE 0x000100000 5444 #define SQLITE_INNOCUOUS 0x000200000 5445 5446 /* 5447 ** CAPI3REF: Deprecated Functions 5448 ** DEPRECATED 5449 ** 5450 ** These functions are [deprecated]. In order to maintain 5451 ** backwards compatibility with older code, these functions continue 5452 ** to be supported. However, new applications should avoid 5453 ** the use of these functions. To encourage programmers to avoid 5454 ** these functions, we will not explain what they do. 5455 */ 5456 #ifndef SQLITE_OMIT_DEPRECATED 5457 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5458 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5459 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5460 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5461 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5462 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5463 void*,sqlite3_int64); 5464 #endif 5465 5466 /* 5467 ** CAPI3REF: Obtaining SQL Values 5468 ** METHOD: sqlite3_value 5469 ** 5470 ** <b>Summary:</b> 5471 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5472 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5473 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5474 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5475 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5476 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5477 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5478 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5479 ** the native byteorder 5480 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5481 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5482 ** <tr><td> <td> <td> 5483 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5484 ** or a UTF-8 TEXT in bytes 5485 ** <tr><td><b>sqlite3_value_bytes16 </b> 5486 ** <td>→ <td>Size of UTF-16 5487 ** TEXT in bytes 5488 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5489 ** datatype of the value 5490 ** <tr><td><b>sqlite3_value_numeric_type </b> 5491 ** <td>→ <td>Best numeric datatype of the value 5492 ** <tr><td><b>sqlite3_value_nochange </b> 5493 ** <td>→ <td>True if the column is unchanged in an UPDATE 5494 ** against a virtual table. 5495 ** <tr><td><b>sqlite3_value_frombind </b> 5496 ** <td>→ <td>True if value originated from a [bound parameter] 5497 ** </table></blockquote> 5498 ** 5499 ** <b>Details:</b> 5500 ** 5501 ** These routines extract type, size, and content information from 5502 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5503 ** are used to pass parameter information into the functions that 5504 ** implement [application-defined SQL functions] and [virtual tables]. 5505 ** 5506 ** These routines work only with [protected sqlite3_value] objects. 5507 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5508 ** is not threadsafe. 5509 ** 5510 ** ^These routines work just like the corresponding [column access functions] 5511 ** except that these routines take a single [protected sqlite3_value] object 5512 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5513 ** 5514 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5515 ** in the native byte-order of the host machine. ^The 5516 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5517 ** extract UTF-16 strings as big-endian and little-endian respectively. 5518 ** 5519 ** ^If [sqlite3_value] object V was initialized 5520 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5521 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5522 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5523 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5524 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5525 ** 5526 ** ^(The sqlite3_value_type(V) interface returns the 5527 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5528 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5529 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5530 ** Other interfaces might change the datatype for an sqlite3_value object. 5531 ** For example, if the datatype is initially SQLITE_INTEGER and 5532 ** sqlite3_value_text(V) is called to extract a text value for that 5533 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5534 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5535 ** occurs is undefined and may change from one release of SQLite to the next. 5536 ** 5537 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5538 ** numeric affinity to the value. This means that an attempt is 5539 ** made to convert the value to an integer or floating point. If 5540 ** such a conversion is possible without loss of information (in other 5541 ** words, if the value is a string that looks like a number) 5542 ** then the conversion is performed. Otherwise no conversion occurs. 5543 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5544 ** 5545 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], 5546 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current encoding 5547 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) 5548 ** returns something other than SQLITE_TEXT, then the return value from 5549 ** sqlite3_value_encoding(X) is meaningless. ^Calls to 5550 ** sqlite3_value_text(X), sqlite3_value_text16(X), sqlite3_value_text16be(X), 5551 ** sqlite3_value_text16le(X), sqlite3_value_bytes(X), or 5552 ** sqlite3_value_bytes16(X) might change the encoding of the value X and 5553 ** thus change the return from subsequent calls to sqlite3_value_encoding(X). 5554 ** 5555 ** ^Within the [xUpdate] method of a [virtual table], the 5556 ** sqlite3_value_nochange(X) interface returns true if and only if 5557 ** the column corresponding to X is unchanged by the UPDATE operation 5558 ** that the xUpdate method call was invoked to implement and if 5559 ** and the prior [xColumn] method call that was invoked to extracted 5560 ** the value for that column returned without setting a result (probably 5561 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5562 ** was unchanging). ^Within an [xUpdate] method, any value for which 5563 ** sqlite3_value_nochange(X) is true will in all other respects appear 5564 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5565 ** than within an [xUpdate] method call for an UPDATE statement, then 5566 ** the return value is arbitrary and meaningless. 5567 ** 5568 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5569 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5570 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5571 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5572 ** 5573 ** Please pay particular attention to the fact that the pointer returned 5574 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5575 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5576 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5577 ** or [sqlite3_value_text16()]. 5578 ** 5579 ** These routines must be called from the same thread as 5580 ** the SQL function that supplied the [sqlite3_value*] parameters. 5581 ** 5582 ** As long as the input parameter is correct, these routines can only 5583 ** fail if an out-of-memory error occurs during a format conversion. 5584 ** Only the following subset of interfaces are subject to out-of-memory 5585 ** errors: 5586 ** 5587 ** <ul> 5588 ** <li> sqlite3_value_blob() 5589 ** <li> sqlite3_value_text() 5590 ** <li> sqlite3_value_text16() 5591 ** <li> sqlite3_value_text16le() 5592 ** <li> sqlite3_value_text16be() 5593 ** <li> sqlite3_value_bytes() 5594 ** <li> sqlite3_value_bytes16() 5595 ** </ul> 5596 ** 5597 ** If an out-of-memory error occurs, then the return value from these 5598 ** routines is the same as if the column had contained an SQL NULL value. 5599 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5600 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5601 ** return value is obtained and before any 5602 ** other SQLite interface is called on the same [database connection]. 5603 */ 5604 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5605 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5606 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5607 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5608 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5609 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5610 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5611 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5612 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5613 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5614 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5615 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5616 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5617 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5618 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5619 SQLITE_API int sqlite3_value_encoding(sqlite3_value*); 5620 5621 /* 5622 ** CAPI3REF: Finding The Subtype Of SQL Values 5623 ** METHOD: sqlite3_value 5624 ** 5625 ** The sqlite3_value_subtype(V) function returns the subtype for 5626 ** an [application-defined SQL function] argument V. The subtype 5627 ** information can be used to pass a limited amount of context from 5628 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5629 ** routine to set the subtype for the return value of an SQL function. 5630 */ 5631 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5632 5633 /* 5634 ** CAPI3REF: Copy And Free SQL Values 5635 ** METHOD: sqlite3_value 5636 ** 5637 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5638 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5639 ** is a [protected sqlite3_value] object even if the input is not. 5640 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5641 ** memory allocation fails. ^If V is a [pointer value], then the result 5642 ** of sqlite3_value_dup(V) is a NULL value. 5643 ** 5644 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5645 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5646 ** then sqlite3_value_free(V) is a harmless no-op. 5647 */ 5648 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5649 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5650 5651 /* 5652 ** CAPI3REF: Obtain Aggregate Function Context 5653 ** METHOD: sqlite3_context 5654 ** 5655 ** Implementations of aggregate SQL functions use this 5656 ** routine to allocate memory for storing their state. 5657 ** 5658 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5659 ** for a particular aggregate function, SQLite allocates 5660 ** N bytes of memory, zeroes out that memory, and returns a pointer 5661 ** to the new memory. ^On second and subsequent calls to 5662 ** sqlite3_aggregate_context() for the same aggregate function instance, 5663 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5664 ** called once for each invocation of the xStep callback and then one 5665 ** last time when the xFinal callback is invoked. ^(When no rows match 5666 ** an aggregate query, the xStep() callback of the aggregate function 5667 ** implementation is never called and xFinal() is called exactly once. 5668 ** In those cases, sqlite3_aggregate_context() might be called for the 5669 ** first time from within xFinal().)^ 5670 ** 5671 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5672 ** when first called if N is less than or equal to zero or if a memory 5673 ** allocation error occurs. 5674 ** 5675 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5676 ** determined by the N parameter on first successful call. Changing the 5677 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5678 ** the same aggregate function instance will not resize the memory 5679 ** allocation.)^ Within the xFinal callback, it is customary to set 5680 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5681 ** pointless memory allocations occur. 5682 ** 5683 ** ^SQLite automatically frees the memory allocated by 5684 ** sqlite3_aggregate_context() when the aggregate query concludes. 5685 ** 5686 ** The first parameter must be a copy of the 5687 ** [sqlite3_context | SQL function context] that is the first parameter 5688 ** to the xStep or xFinal callback routine that implements the aggregate 5689 ** function. 5690 ** 5691 ** This routine must be called from the same thread in which 5692 ** the aggregate SQL function is running. 5693 */ 5694 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5695 5696 /* 5697 ** CAPI3REF: User Data For Functions 5698 ** METHOD: sqlite3_context 5699 ** 5700 ** ^The sqlite3_user_data() interface returns a copy of 5701 ** the pointer that was the pUserData parameter (the 5th parameter) 5702 ** of the [sqlite3_create_function()] 5703 ** and [sqlite3_create_function16()] routines that originally 5704 ** registered the application defined function. 5705 ** 5706 ** This routine must be called from the same thread in which 5707 ** the application-defined function is running. 5708 */ 5709 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5710 5711 /* 5712 ** CAPI3REF: Database Connection For Functions 5713 ** METHOD: sqlite3_context 5714 ** 5715 ** ^The sqlite3_context_db_handle() interface returns a copy of 5716 ** the pointer to the [database connection] (the 1st parameter) 5717 ** of the [sqlite3_create_function()] 5718 ** and [sqlite3_create_function16()] routines that originally 5719 ** registered the application defined function. 5720 */ 5721 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5722 5723 /* 5724 ** CAPI3REF: Function Auxiliary Data 5725 ** METHOD: sqlite3_context 5726 ** 5727 ** These functions may be used by (non-aggregate) SQL functions to 5728 ** associate metadata with argument values. If the same value is passed to 5729 ** multiple invocations of the same SQL function during query execution, under 5730 ** some circumstances the associated metadata may be preserved. An example 5731 ** of where this might be useful is in a regular-expression matching 5732 ** function. The compiled version of the regular expression can be stored as 5733 ** metadata associated with the pattern string. 5734 ** Then as long as the pattern string remains the same, 5735 ** the compiled regular expression can be reused on multiple 5736 ** invocations of the same function. 5737 ** 5738 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5739 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5740 ** value to the application-defined function. ^N is zero for the left-most 5741 ** function argument. ^If there is no metadata 5742 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5743 ** returns a NULL pointer. 5744 ** 5745 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5746 ** argument of the application-defined function. ^Subsequent 5747 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5748 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5749 ** NULL if the metadata has been discarded. 5750 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5751 ** SQLite will invoke the destructor function X with parameter P exactly 5752 ** once, when the metadata is discarded. 5753 ** SQLite is free to discard the metadata at any time, including: <ul> 5754 ** <li> ^(when the corresponding function parameter changes)^, or 5755 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5756 ** SQL statement)^, or 5757 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5758 ** parameter)^, or 5759 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5760 ** allocation error occurs.)^ </ul> 5761 ** 5762 ** Note the last bullet in particular. The destructor X in 5763 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5764 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5765 ** should be called near the end of the function implementation and the 5766 ** function implementation should not make any use of P after 5767 ** sqlite3_set_auxdata() has been called. 5768 ** 5769 ** ^(In practice, metadata is preserved between function calls for 5770 ** function parameters that are compile-time constants, including literal 5771 ** values and [parameters] and expressions composed from the same.)^ 5772 ** 5773 ** The value of the N parameter to these interfaces should be non-negative. 5774 ** Future enhancements may make use of negative N values to define new 5775 ** kinds of function caching behavior. 5776 ** 5777 ** These routines must be called from the same thread in which 5778 ** the SQL function is running. 5779 */ 5780 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5781 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5782 5783 5784 /* 5785 ** CAPI3REF: Constants Defining Special Destructor Behavior 5786 ** 5787 ** These are special values for the destructor that is passed in as the 5788 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5789 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5790 ** and will never change. It does not need to be destroyed. ^The 5791 ** SQLITE_TRANSIENT value means that the content will likely change in 5792 ** the near future and that SQLite should make its own private copy of 5793 ** the content before returning. 5794 ** 5795 ** The typedef is necessary to work around problems in certain 5796 ** C++ compilers. 5797 */ 5798 typedef void (*sqlite3_destructor_type)(void*); 5799 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5800 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5801 5802 /* 5803 ** CAPI3REF: Setting The Result Of An SQL Function 5804 ** METHOD: sqlite3_context 5805 ** 5806 ** These routines are used by the xFunc or xFinal callbacks that 5807 ** implement SQL functions and aggregates. See 5808 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5809 ** for additional information. 5810 ** 5811 ** These functions work very much like the [parameter binding] family of 5812 ** functions used to bind values to host parameters in prepared statements. 5813 ** Refer to the [SQL parameter] documentation for additional information. 5814 ** 5815 ** ^The sqlite3_result_blob() interface sets the result from 5816 ** an application-defined function to be the BLOB whose content is pointed 5817 ** to by the second parameter and which is N bytes long where N is the 5818 ** third parameter. 5819 ** 5820 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5821 ** interfaces set the result of the application-defined function to be 5822 ** a BLOB containing all zero bytes and N bytes in size. 5823 ** 5824 ** ^The sqlite3_result_double() interface sets the result from 5825 ** an application-defined function to be a floating point value specified 5826 ** by its 2nd argument. 5827 ** 5828 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5829 ** cause the implemented SQL function to throw an exception. 5830 ** ^SQLite uses the string pointed to by the 5831 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5832 ** as the text of an error message. ^SQLite interprets the error 5833 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5834 ** interprets the string from sqlite3_result_error16() as UTF-16 using 5835 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5836 ** ^If the third parameter to sqlite3_result_error() 5837 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5838 ** message all text up through the first zero character. 5839 ** ^If the third parameter to sqlite3_result_error() or 5840 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5841 ** bytes (not characters) from the 2nd parameter as the error message. 5842 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5843 ** routines make a private copy of the error message text before 5844 ** they return. Hence, the calling function can deallocate or 5845 ** modify the text after they return without harm. 5846 ** ^The sqlite3_result_error_code() function changes the error code 5847 ** returned by SQLite as a result of an error in a function. ^By default, 5848 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5849 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5850 ** 5851 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5852 ** error indicating that a string or BLOB is too long to represent. 5853 ** 5854 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5855 ** error indicating that a memory allocation failed. 5856 ** 5857 ** ^The sqlite3_result_int() interface sets the return value 5858 ** of the application-defined function to be the 32-bit signed integer 5859 ** value given in the 2nd argument. 5860 ** ^The sqlite3_result_int64() interface sets the return value 5861 ** of the application-defined function to be the 64-bit signed integer 5862 ** value given in the 2nd argument. 5863 ** 5864 ** ^The sqlite3_result_null() interface sets the return value 5865 ** of the application-defined function to be NULL. 5866 ** 5867 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5868 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5869 ** set the return value of the application-defined function to be 5870 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5871 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5872 ** ^The sqlite3_result_text64() interface sets the return value of an 5873 ** application-defined function to be a text string in an encoding 5874 ** specified by the fifth (and last) parameter, which must be one 5875 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5876 ** ^SQLite takes the text result from the application from 5877 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5878 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces 5879 ** other than sqlite3_result_text64() is negative, then SQLite computes 5880 ** the string length itself by searching the 2nd parameter for the first 5881 ** zero character. 5882 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5883 ** is non-negative, then as many bytes (not characters) of the text 5884 ** pointed to by the 2nd parameter are taken as the application-defined 5885 ** function result. If the 3rd parameter is non-negative, then it 5886 ** must be the byte offset into the string where the NUL terminator would 5887 ** appear if the string where NUL terminated. If any NUL characters occur 5888 ** in the string at a byte offset that is less than the value of the 3rd 5889 ** parameter, then the resulting string will contain embedded NULs and the 5890 ** result of expressions operating on strings with embedded NULs is undefined. 5891 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5892 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5893 ** function as the destructor on the text or BLOB result when it has 5894 ** finished using that result. 5895 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5896 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5897 ** assumes that the text or BLOB result is in constant space and does not 5898 ** copy the content of the parameter nor call a destructor on the content 5899 ** when it has finished using that result. 5900 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5901 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5902 ** then SQLite makes a copy of the result into space obtained 5903 ** from [sqlite3_malloc()] before it returns. 5904 ** 5905 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5906 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5907 ** when the encoding is not UTF8, if the input UTF16 begins with a 5908 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5909 ** string and the rest of the string is interpreted according to the 5910 ** byte-order specified by the BOM. ^The byte-order specified by 5911 ** the BOM at the beginning of the text overrides the byte-order 5912 ** specified by the interface procedure. ^So, for example, if 5913 ** sqlite3_result_text16le() is invoked with text that begins 5914 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5915 ** first two bytes of input are skipped and the remaining input 5916 ** is interpreted as UTF16BE text. 5917 ** 5918 ** ^For UTF16 input text to the sqlite3_result_text16(), 5919 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5920 ** sqlite3_result_text64() routines, if the text contains invalid 5921 ** UTF16 characters, the invalid characters might be converted 5922 ** into the unicode replacement character, U+FFFD. 5923 ** 5924 ** ^The sqlite3_result_value() interface sets the result of 5925 ** the application-defined function to be a copy of the 5926 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5927 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5928 ** so that the [sqlite3_value] specified in the parameter may change or 5929 ** be deallocated after sqlite3_result_value() returns without harm. 5930 ** ^A [protected sqlite3_value] object may always be used where an 5931 ** [unprotected sqlite3_value] object is required, so either 5932 ** kind of [sqlite3_value] object can be used with this interface. 5933 ** 5934 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5935 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5936 ** also associates the host-language pointer P or type T with that 5937 ** NULL value such that the pointer can be retrieved within an 5938 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5939 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5940 ** for the P parameter. ^SQLite invokes D with P as its only argument 5941 ** when SQLite is finished with P. The T parameter should be a static 5942 ** string and preferably a string literal. The sqlite3_result_pointer() 5943 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5944 ** 5945 ** If these routines are called from within the different thread 5946 ** than the one containing the application-defined function that received 5947 ** the [sqlite3_context] pointer, the results are undefined. 5948 */ 5949 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5950 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5951 sqlite3_uint64,void(*)(void*)); 5952 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5953 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5954 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5955 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5956 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5957 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5958 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5959 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5960 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5961 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5962 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5963 void(*)(void*), unsigned char encoding); 5964 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5965 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5966 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5967 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5968 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5969 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5970 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5971 5972 5973 /* 5974 ** CAPI3REF: Setting The Subtype Of An SQL Function 5975 ** METHOD: sqlite3_context 5976 ** 5977 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5978 ** the result from the [application-defined SQL function] with 5979 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5980 ** of the subtype T are preserved in current versions of SQLite; 5981 ** higher order bits are discarded. 5982 ** The number of subtype bytes preserved by SQLite might increase 5983 ** in future releases of SQLite. 5984 */ 5985 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5986 5987 /* 5988 ** CAPI3REF: Define New Collating Sequences 5989 ** METHOD: sqlite3 5990 ** 5991 ** ^These functions add, remove, or modify a [collation] associated 5992 ** with the [database connection] specified as the first argument. 5993 ** 5994 ** ^The name of the collation is a UTF-8 string 5995 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5996 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5997 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5998 ** considered to be the same name. 5999 ** 6000 ** ^(The third argument (eTextRep) must be one of the constants: 6001 ** <ul> 6002 ** <li> [SQLITE_UTF8], 6003 ** <li> [SQLITE_UTF16LE], 6004 ** <li> [SQLITE_UTF16BE], 6005 ** <li> [SQLITE_UTF16], or 6006 ** <li> [SQLITE_UTF16_ALIGNED]. 6007 ** </ul>)^ 6008 ** ^The eTextRep argument determines the encoding of strings passed 6009 ** to the collating function callback, xCompare. 6010 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 6011 ** force strings to be UTF16 with native byte order. 6012 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 6013 ** on an even byte address. 6014 ** 6015 ** ^The fourth argument, pArg, is an application data pointer that is passed 6016 ** through as the first argument to the collating function callback. 6017 ** 6018 ** ^The fifth argument, xCompare, is a pointer to the collating function. 6019 ** ^Multiple collating functions can be registered using the same name but 6020 ** with different eTextRep parameters and SQLite will use whichever 6021 ** function requires the least amount of data transformation. 6022 ** ^If the xCompare argument is NULL then the collating function is 6023 ** deleted. ^When all collating functions having the same name are deleted, 6024 ** that collation is no longer usable. 6025 ** 6026 ** ^The collating function callback is invoked with a copy of the pArg 6027 ** application data pointer and with two strings in the encoding specified 6028 ** by the eTextRep argument. The two integer parameters to the collating 6029 ** function callback are the length of the two strings, in bytes. The collating 6030 ** function must return an integer that is negative, zero, or positive 6031 ** if the first string is less than, equal to, or greater than the second, 6032 ** respectively. A collating function must always return the same answer 6033 ** given the same inputs. If two or more collating functions are registered 6034 ** to the same collation name (using different eTextRep values) then all 6035 ** must give an equivalent answer when invoked with equivalent strings. 6036 ** The collating function must obey the following properties for all 6037 ** strings A, B, and C: 6038 ** 6039 ** <ol> 6040 ** <li> If A==B then B==A. 6041 ** <li> If A==B and B==C then A==C. 6042 ** <li> If A<B THEN B>A. 6043 ** <li> If A<B and B<C then A<C. 6044 ** </ol> 6045 ** 6046 ** If a collating function fails any of the above constraints and that 6047 ** collating function is registered and used, then the behavior of SQLite 6048 ** is undefined. 6049 ** 6050 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6051 ** with the addition that the xDestroy callback is invoked on pArg when 6052 ** the collating function is deleted. 6053 ** ^Collating functions are deleted when they are overridden by later 6054 ** calls to the collation creation functions or when the 6055 ** [database connection] is closed using [sqlite3_close()]. 6056 ** 6057 ** ^The xDestroy callback is <u>not</u> called if the 6058 ** sqlite3_create_collation_v2() function fails. Applications that invoke 6059 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6060 ** check the return code and dispose of the application data pointer 6061 ** themselves rather than expecting SQLite to deal with it for them. 6062 ** This is different from every other SQLite interface. The inconsistency 6063 ** is unfortunate but cannot be changed without breaking backwards 6064 ** compatibility. 6065 ** 6066 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6067 */ 6068 SQLITE_API int sqlite3_create_collation( 6069 sqlite3*, 6070 const char *zName, 6071 int eTextRep, 6072 void *pArg, 6073 int(*xCompare)(void*,int,const void*,int,const void*) 6074 ); 6075 SQLITE_API int sqlite3_create_collation_v2( 6076 sqlite3*, 6077 const char *zName, 6078 int eTextRep, 6079 void *pArg, 6080 int(*xCompare)(void*,int,const void*,int,const void*), 6081 void(*xDestroy)(void*) 6082 ); 6083 SQLITE_API int sqlite3_create_collation16( 6084 sqlite3*, 6085 const void *zName, 6086 int eTextRep, 6087 void *pArg, 6088 int(*xCompare)(void*,int,const void*,int,const void*) 6089 ); 6090 6091 /* 6092 ** CAPI3REF: Collation Needed Callbacks 6093 ** METHOD: sqlite3 6094 ** 6095 ** ^To avoid having to register all collation sequences before a database 6096 ** can be used, a single callback function may be registered with the 6097 ** [database connection] to be invoked whenever an undefined collation 6098 ** sequence is required. 6099 ** 6100 ** ^If the function is registered using the sqlite3_collation_needed() API, 6101 ** then it is passed the names of undefined collation sequences as strings 6102 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6103 ** the names are passed as UTF-16 in machine native byte order. 6104 ** ^A call to either function replaces the existing collation-needed callback. 6105 ** 6106 ** ^(When the callback is invoked, the first argument passed is a copy 6107 ** of the second argument to sqlite3_collation_needed() or 6108 ** sqlite3_collation_needed16(). The second argument is the database 6109 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6110 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6111 ** sequence function required. The fourth parameter is the name of the 6112 ** required collation sequence.)^ 6113 ** 6114 ** The callback function should register the desired collation using 6115 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6116 ** [sqlite3_create_collation_v2()]. 6117 */ 6118 SQLITE_API int sqlite3_collation_needed( 6119 sqlite3*, 6120 void*, 6121 void(*)(void*,sqlite3*,int eTextRep,const char*) 6122 ); 6123 SQLITE_API int sqlite3_collation_needed16( 6124 sqlite3*, 6125 void*, 6126 void(*)(void*,sqlite3*,int eTextRep,const void*) 6127 ); 6128 6129 #ifdef SQLITE_ENABLE_CEROD 6130 /* 6131 ** Specify the activation key for a CEROD database. Unless 6132 ** activated, none of the CEROD routines will work. 6133 */ 6134 SQLITE_API void sqlite3_activate_cerod( 6135 const char *zPassPhrase /* Activation phrase */ 6136 ); 6137 #endif 6138 6139 /* 6140 ** CAPI3REF: Suspend Execution For A Short Time 6141 ** 6142 ** The sqlite3_sleep() function causes the current thread to suspend execution 6143 ** for at least a number of milliseconds specified in its parameter. 6144 ** 6145 ** If the operating system does not support sleep requests with 6146 ** millisecond time resolution, then the time will be rounded up to 6147 ** the nearest second. The number of milliseconds of sleep actually 6148 ** requested from the operating system is returned. 6149 ** 6150 ** ^SQLite implements this interface by calling the xSleep() 6151 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6152 ** of the default VFS is not implemented correctly, or not implemented at 6153 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6154 ** in the previous paragraphs. 6155 */ 6156 SQLITE_API int sqlite3_sleep(int); 6157 6158 /* 6159 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6160 ** 6161 ** ^(If this global variable is made to point to a string which is 6162 ** the name of a folder (a.k.a. directory), then all temporary files 6163 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6164 ** will be placed in that directory.)^ ^If this variable 6165 ** is a NULL pointer, then SQLite performs a search for an appropriate 6166 ** temporary file directory. 6167 ** 6168 ** Applications are strongly discouraged from using this global variable. 6169 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6170 ** But for all other platforms, it is highly recommended that applications 6171 ** neither read nor write this variable. This global variable is a relic 6172 ** that exists for backwards compatibility of legacy applications and should 6173 ** be avoided in new projects. 6174 ** 6175 ** It is not safe to read or modify this variable in more than one 6176 ** thread at a time. It is not safe to read or modify this variable 6177 ** if a [database connection] is being used at the same time in a separate 6178 ** thread. 6179 ** It is intended that this variable be set once 6180 ** as part of process initialization and before any SQLite interface 6181 ** routines have been called and that this variable remain unchanged 6182 ** thereafter. 6183 ** 6184 ** ^The [temp_store_directory pragma] may modify this variable and cause 6185 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6186 ** the [temp_store_directory pragma] always assumes that any string 6187 ** that this variable points to is held in memory obtained from 6188 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6189 ** using [sqlite3_free]. 6190 ** Hence, if this variable is modified directly, either it should be 6191 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6192 ** or else the use of the [temp_store_directory pragma] should be avoided. 6193 ** Except when requested by the [temp_store_directory pragma], SQLite 6194 ** does not free the memory that sqlite3_temp_directory points to. If 6195 ** the application wants that memory to be freed, it must do 6196 ** so itself, taking care to only do so after all [database connection] 6197 ** objects have been destroyed. 6198 ** 6199 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6200 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6201 ** features that require the use of temporary files may fail. Here is an 6202 ** example of how to do this using C++ with the Windows Runtime: 6203 ** 6204 ** <blockquote><pre> 6205 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6206 ** TemporaryFolder->Path->Data(); 6207 ** char zPathBuf[MAX_PATH + 1]; 6208 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6209 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6210 ** NULL, NULL); 6211 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6212 ** </pre></blockquote> 6213 */ 6214 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6215 6216 /* 6217 ** CAPI3REF: Name Of The Folder Holding Database Files 6218 ** 6219 ** ^(If this global variable is made to point to a string which is 6220 ** the name of a folder (a.k.a. directory), then all database files 6221 ** specified with a relative pathname and created or accessed by 6222 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6223 ** to be relative to that directory.)^ ^If this variable is a NULL 6224 ** pointer, then SQLite assumes that all database files specified 6225 ** with a relative pathname are relative to the current directory 6226 ** for the process. Only the windows VFS makes use of this global 6227 ** variable; it is ignored by the unix VFS. 6228 ** 6229 ** Changing the value of this variable while a database connection is 6230 ** open can result in a corrupt database. 6231 ** 6232 ** It is not safe to read or modify this variable in more than one 6233 ** thread at a time. It is not safe to read or modify this variable 6234 ** if a [database connection] is being used at the same time in a separate 6235 ** thread. 6236 ** It is intended that this variable be set once 6237 ** as part of process initialization and before any SQLite interface 6238 ** routines have been called and that this variable remain unchanged 6239 ** thereafter. 6240 ** 6241 ** ^The [data_store_directory pragma] may modify this variable and cause 6242 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6243 ** the [data_store_directory pragma] always assumes that any string 6244 ** that this variable points to is held in memory obtained from 6245 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6246 ** using [sqlite3_free]. 6247 ** Hence, if this variable is modified directly, either it should be 6248 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6249 ** or else the use of the [data_store_directory pragma] should be avoided. 6250 */ 6251 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6252 6253 /* 6254 ** CAPI3REF: Win32 Specific Interface 6255 ** 6256 ** These interfaces are available only on Windows. The 6257 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6258 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6259 ** zValue, depending on the value of the type parameter. The zValue parameter 6260 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6261 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6262 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6263 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6264 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6265 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6266 ** the current directory on the sub-platforms of Win32 where that concept is 6267 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6268 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6269 ** sqlite3_win32_set_directory interface except the string parameter must be 6270 ** UTF-8 or UTF-16, respectively. 6271 */ 6272 SQLITE_API int sqlite3_win32_set_directory( 6273 unsigned long type, /* Identifier for directory being set or reset */ 6274 void *zValue /* New value for directory being set or reset */ 6275 ); 6276 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6277 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6278 6279 /* 6280 ** CAPI3REF: Win32 Directory Types 6281 ** 6282 ** These macros are only available on Windows. They define the allowed values 6283 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6284 */ 6285 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6286 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6287 6288 /* 6289 ** CAPI3REF: Test For Auto-Commit Mode 6290 ** KEYWORDS: {autocommit mode} 6291 ** METHOD: sqlite3 6292 ** 6293 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6294 ** zero if the given database connection is or is not in autocommit mode, 6295 ** respectively. ^Autocommit mode is on by default. 6296 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6297 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6298 ** 6299 ** If certain kinds of errors occur on a statement within a multi-statement 6300 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6301 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6302 ** transaction might be rolled back automatically. The only way to 6303 ** find out whether SQLite automatically rolled back the transaction after 6304 ** an error is to use this function. 6305 ** 6306 ** If another thread changes the autocommit status of the database 6307 ** connection while this routine is running, then the return value 6308 ** is undefined. 6309 */ 6310 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6311 6312 /* 6313 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6314 ** METHOD: sqlite3_stmt 6315 ** 6316 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6317 ** to which a [prepared statement] belongs. ^The [database connection] 6318 ** returned by sqlite3_db_handle is the same [database connection] 6319 ** that was the first argument 6320 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6321 ** create the statement in the first place. 6322 */ 6323 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6324 6325 /* 6326 ** CAPI3REF: Return The Schema Name For A Database Connection 6327 ** METHOD: sqlite3 6328 ** 6329 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6330 ** for the N-th database on database connection D, or a NULL pointer of N is 6331 ** out of range. An N value of 0 means the main database file. An N of 1 is 6332 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6333 ** databases. 6334 ** 6335 ** Space to hold the string that is returned by sqlite3_db_name() is managed 6336 ** by SQLite itself. The string might be deallocated by any operation that 6337 ** changes the schema, including [ATTACH] or [DETACH] or calls to 6338 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6339 ** occur on a different thread. Applications that need to 6340 ** remember the string long-term should make their own copy. Applications that 6341 ** are accessing the same database connection simultaneously on multiple 6342 ** threads should mutex-protect calls to this API and should make their own 6343 ** private copy of the result prior to releasing the mutex. 6344 */ 6345 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6346 6347 /* 6348 ** CAPI3REF: Return The Filename For A Database Connection 6349 ** METHOD: sqlite3 6350 ** 6351 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6352 ** associated with database N of connection D. 6353 ** ^If there is no attached database N on the database 6354 ** connection D, or if database N is a temporary or in-memory database, then 6355 ** this function will return either a NULL pointer or an empty string. 6356 ** 6357 ** ^The string value returned by this routine is owned and managed by 6358 ** the database connection. ^The value will be valid until the database N 6359 ** is [DETACH]-ed or until the database connection closes. 6360 ** 6361 ** ^The filename returned by this function is the output of the 6362 ** xFullPathname method of the [VFS]. ^In other words, the filename 6363 ** will be an absolute pathname, even if the filename used 6364 ** to open the database originally was a URI or relative pathname. 6365 ** 6366 ** If the filename pointer returned by this routine is not NULL, then it 6367 ** can be used as the filename input parameter to these routines: 6368 ** <ul> 6369 ** <li> [sqlite3_uri_parameter()] 6370 ** <li> [sqlite3_uri_boolean()] 6371 ** <li> [sqlite3_uri_int64()] 6372 ** <li> [sqlite3_filename_database()] 6373 ** <li> [sqlite3_filename_journal()] 6374 ** <li> [sqlite3_filename_wal()] 6375 ** </ul> 6376 */ 6377 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6378 6379 /* 6380 ** CAPI3REF: Determine if a database is read-only 6381 ** METHOD: sqlite3 6382 ** 6383 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6384 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6385 ** the name of a database on connection D. 6386 */ 6387 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6388 6389 /* 6390 ** CAPI3REF: Determine the transaction state of a database 6391 ** METHOD: sqlite3 6392 ** 6393 ** ^The sqlite3_txn_state(D,S) interface returns the current 6394 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6395 ** then the highest transaction state of any schema on database connection D 6396 ** is returned. Transaction states are (in order of lowest to highest): 6397 ** <ol> 6398 ** <li value="0"> SQLITE_TXN_NONE 6399 ** <li value="1"> SQLITE_TXN_READ 6400 ** <li value="2"> SQLITE_TXN_WRITE 6401 ** </ol> 6402 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6403 ** a valid schema, then -1 is returned. 6404 */ 6405 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6406 6407 /* 6408 ** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6409 ** KEYWORDS: {transaction state} 6410 ** 6411 ** These constants define the current transaction state of a database file. 6412 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6413 ** constants in order to describe the transaction state of schema S 6414 ** in [database connection] D. 6415 ** 6416 ** <dl> 6417 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6418 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6419 ** pending.</dd> 6420 ** 6421 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6422 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6423 ** in a read transaction. Content has been read from the database file 6424 ** but nothing in the database file has changed. The transaction state 6425 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6426 ** no other conflicting concurrent write transactions. The transaction 6427 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6428 ** [COMMIT].</dd> 6429 ** 6430 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6431 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6432 ** in a write transaction. Content has been written to the database file 6433 ** but has not yet committed. The transaction state will change to 6434 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6435 */ 6436 #define SQLITE_TXN_NONE 0 6437 #define SQLITE_TXN_READ 1 6438 #define SQLITE_TXN_WRITE 2 6439 6440 /* 6441 ** CAPI3REF: Find the next prepared statement 6442 ** METHOD: sqlite3 6443 ** 6444 ** ^This interface returns a pointer to the next [prepared statement] after 6445 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6446 ** then this interface returns a pointer to the first prepared statement 6447 ** associated with the database connection pDb. ^If no prepared statement 6448 ** satisfies the conditions of this routine, it returns NULL. 6449 ** 6450 ** The [database connection] pointer D in a call to 6451 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6452 ** connection and in particular must not be a NULL pointer. 6453 */ 6454 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6455 6456 /* 6457 ** CAPI3REF: Commit And Rollback Notification Callbacks 6458 ** METHOD: sqlite3 6459 ** 6460 ** ^The sqlite3_commit_hook() interface registers a callback 6461 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6462 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6463 ** for the same database connection is overridden. 6464 ** ^The sqlite3_rollback_hook() interface registers a callback 6465 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6466 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6467 ** for the same database connection is overridden. 6468 ** ^The pArg argument is passed through to the callback. 6469 ** ^If the callback on a commit hook function returns non-zero, 6470 ** then the commit is converted into a rollback. 6471 ** 6472 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6473 ** return the P argument from the previous call of the same function 6474 ** on the same [database connection] D, or NULL for 6475 ** the first call for each function on D. 6476 ** 6477 ** The commit and rollback hook callbacks are not reentrant. 6478 ** The callback implementation must not do anything that will modify 6479 ** the database connection that invoked the callback. Any actions 6480 ** to modify the database connection must be deferred until after the 6481 ** completion of the [sqlite3_step()] call that triggered the commit 6482 ** or rollback hook in the first place. 6483 ** Note that running any other SQL statements, including SELECT statements, 6484 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6485 ** the database connections for the meaning of "modify" in this paragraph. 6486 ** 6487 ** ^Registering a NULL function disables the callback. 6488 ** 6489 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6490 ** operation is allowed to continue normally. ^If the commit hook 6491 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6492 ** ^The rollback hook is invoked on a rollback that results from a commit 6493 ** hook returning non-zero, just as it would be with any other rollback. 6494 ** 6495 ** ^For the purposes of this API, a transaction is said to have been 6496 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6497 ** an error or constraint causes an implicit rollback to occur. 6498 ** ^The rollback callback is not invoked if a transaction is 6499 ** automatically rolled back because the database connection is closed. 6500 ** 6501 ** See also the [sqlite3_update_hook()] interface. 6502 */ 6503 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6504 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6505 6506 /* 6507 ** CAPI3REF: Autovacuum Compaction Amount Callback 6508 ** METHOD: sqlite3 6509 ** 6510 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 6511 ** function C that is invoked prior to each autovacuum of the database 6512 ** file. ^The callback is passed a copy of the generic data pointer (P), 6513 ** the schema-name of the attached database that is being autovacuumed, 6514 ** the size of the database file in pages, the number of free pages, 6515 ** and the number of bytes per page, respectively. The callback should 6516 ** return the number of free pages that should be removed by the 6517 ** autovacuum. ^If the callback returns zero, then no autovacuum happens. 6518 ** ^If the value returned is greater than or equal to the number of 6519 ** free pages, then a complete autovacuum happens. 6520 ** 6521 ** <p>^If there are multiple ATTACH-ed database files that are being 6522 ** modified as part of a transaction commit, then the autovacuum pages 6523 ** callback is invoked separately for each file. 6524 ** 6525 ** <p><b>The callback is not reentrant.</b> The callback function should 6526 ** not attempt to invoke any other SQLite interface. If it does, bad 6527 ** things may happen, including segmentation faults and corrupt database 6528 ** files. The callback function should be a simple function that 6529 ** does some arithmetic on its input parameters and returns a result. 6530 ** 6531 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 6532 ** destructor for the P parameter. ^If X is not NULL, then X(P) is 6533 ** invoked whenever the database connection closes or when the callback 6534 ** is overwritten by another invocation of sqlite3_autovacuum_pages(). 6535 ** 6536 ** <p>^There is only one autovacuum pages callback per database connection. 6537 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 6538 ** previous invocations for that database connection. ^If the callback 6539 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 6540 ** then the autovacuum steps callback is cancelled. The return value 6541 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 6542 ** be some other error code if something goes wrong. The current 6543 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 6544 ** return codes might be added in future releases. 6545 ** 6546 ** <p>If no autovacuum pages callback is specified (the usual case) or 6547 ** a NULL pointer is provided for the callback, 6548 ** then the default behavior is to vacuum all free pages. So, in other 6549 ** words, the default behavior is the same as if the callback function 6550 ** were something like this: 6551 ** 6552 ** <blockquote><pre> 6553 ** unsigned int demonstration_autovac_pages_callback( 6554 ** void *pClientData, 6555 ** const char *zSchema, 6556 ** unsigned int nDbPage, 6557 ** unsigned int nFreePage, 6558 ** unsigned int nBytePerPage 6559 ** ){ 6560 ** return nFreePage; 6561 ** } 6562 ** </pre></blockquote> 6563 */ 6564 SQLITE_API int sqlite3_autovacuum_pages( 6565 sqlite3 *db, 6566 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 6567 void*, 6568 void(*)(void*) 6569 ); 6570 6571 6572 /* 6573 ** CAPI3REF: Data Change Notification Callbacks 6574 ** METHOD: sqlite3 6575 ** 6576 ** ^The sqlite3_update_hook() interface registers a callback function 6577 ** with the [database connection] identified by the first argument 6578 ** to be invoked whenever a row is updated, inserted or deleted in 6579 ** a [rowid table]. 6580 ** ^Any callback set by a previous call to this function 6581 ** for the same database connection is overridden. 6582 ** 6583 ** ^The second argument is a pointer to the function to invoke when a 6584 ** row is updated, inserted or deleted in a rowid table. 6585 ** ^The first argument to the callback is a copy of the third argument 6586 ** to sqlite3_update_hook(). 6587 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6588 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6589 ** to be invoked. 6590 ** ^The third and fourth arguments to the callback contain pointers to the 6591 ** database and table name containing the affected row. 6592 ** ^The final callback parameter is the [rowid] of the row. 6593 ** ^In the case of an update, this is the [rowid] after the update takes place. 6594 ** 6595 ** ^(The update hook is not invoked when internal system tables are 6596 ** modified (i.e. sqlite_sequence).)^ 6597 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6598 ** 6599 ** ^In the current implementation, the update hook 6600 ** is not invoked when conflicting rows are deleted because of an 6601 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6602 ** invoked when rows are deleted using the [truncate optimization]. 6603 ** The exceptions defined in this paragraph might change in a future 6604 ** release of SQLite. 6605 ** 6606 ** The update hook implementation must not do anything that will modify 6607 ** the database connection that invoked the update hook. Any actions 6608 ** to modify the database connection must be deferred until after the 6609 ** completion of the [sqlite3_step()] call that triggered the update hook. 6610 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6611 ** database connections for the meaning of "modify" in this paragraph. 6612 ** 6613 ** ^The sqlite3_update_hook(D,C,P) function 6614 ** returns the P argument from the previous call 6615 ** on the same [database connection] D, or NULL for 6616 ** the first call on D. 6617 ** 6618 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6619 ** and [sqlite3_preupdate_hook()] interfaces. 6620 */ 6621 SQLITE_API void *sqlite3_update_hook( 6622 sqlite3*, 6623 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6624 void* 6625 ); 6626 6627 /* 6628 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6629 ** 6630 ** ^(This routine enables or disables the sharing of the database cache 6631 ** and schema data structures between [database connection | connections] 6632 ** to the same database. Sharing is enabled if the argument is true 6633 ** and disabled if the argument is false.)^ 6634 ** 6635 ** This interface is omitted if SQLite is compiled with 6636 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] 6637 ** compile-time option is recommended because the 6638 ** [use of shared cache mode is discouraged]. 6639 ** 6640 ** ^Cache sharing is enabled and disabled for an entire process. 6641 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6642 ** In prior versions of SQLite, 6643 ** sharing was enabled or disabled for each thread separately. 6644 ** 6645 ** ^(The cache sharing mode set by this interface effects all subsequent 6646 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6647 ** Existing database connections continue to use the sharing mode 6648 ** that was in effect at the time they were opened.)^ 6649 ** 6650 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6651 ** successfully. An [error code] is returned otherwise.)^ 6652 ** 6653 ** ^Shared cache is disabled by default. It is recommended that it stay 6654 ** that way. In other words, do not use this routine. This interface 6655 ** continues to be provided for historical compatibility, but its use is 6656 ** discouraged. Any use of shared cache is discouraged. If shared cache 6657 ** must be used, it is recommended that shared cache only be enabled for 6658 ** individual database connections using the [sqlite3_open_v2()] interface 6659 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6660 ** 6661 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6662 ** and will always return SQLITE_MISUSE. On those systems, 6663 ** shared cache mode should be enabled per-database connection via 6664 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6665 ** 6666 ** This interface is threadsafe on processors where writing a 6667 ** 32-bit integer is atomic. 6668 ** 6669 ** See Also: [SQLite Shared-Cache Mode] 6670 */ 6671 SQLITE_API int sqlite3_enable_shared_cache(int); 6672 6673 /* 6674 ** CAPI3REF: Attempt To Free Heap Memory 6675 ** 6676 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6677 ** of heap memory by deallocating non-essential memory allocations 6678 ** held by the database library. Memory used to cache database 6679 ** pages to improve performance is an example of non-essential memory. 6680 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6681 ** which might be more or less than the amount requested. 6682 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6683 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6684 ** 6685 ** See also: [sqlite3_db_release_memory()] 6686 */ 6687 SQLITE_API int sqlite3_release_memory(int); 6688 6689 /* 6690 ** CAPI3REF: Free Memory Used By A Database Connection 6691 ** METHOD: sqlite3 6692 ** 6693 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6694 ** memory as possible from database connection D. Unlike the 6695 ** [sqlite3_release_memory()] interface, this interface is in effect even 6696 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6697 ** omitted. 6698 ** 6699 ** See also: [sqlite3_release_memory()] 6700 */ 6701 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6702 6703 /* 6704 ** CAPI3REF: Impose A Limit On Heap Size 6705 ** 6706 ** These interfaces impose limits on the amount of heap memory that will be 6707 ** by all database connections within a single process. 6708 ** 6709 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6710 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6711 ** ^SQLite strives to keep heap memory utilization below the soft heap 6712 ** limit by reducing the number of pages held in the page cache 6713 ** as heap memory usages approaches the limit. 6714 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6715 ** below the limit, it will exceed the limit rather than generate 6716 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6717 ** is advisory only. 6718 ** 6719 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6720 ** N bytes on the amount of memory that will be allocated. ^The 6721 ** sqlite3_hard_heap_limit64(N) interface is similar to 6722 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6723 ** when the hard heap limit is reached. 6724 ** 6725 ** ^The return value from both sqlite3_soft_heap_limit64() and 6726 ** sqlite3_hard_heap_limit64() is the size of 6727 ** the heap limit prior to the call, or negative in the case of an 6728 ** error. ^If the argument N is negative 6729 ** then no change is made to the heap limit. Hence, the current 6730 ** size of heap limits can be determined by invoking 6731 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6732 ** 6733 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6734 ** 6735 ** ^The soft heap limit may not be greater than the hard heap limit. 6736 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6737 ** is invoked with a value of N that is greater than the hard heap limit, 6738 ** the soft heap limit is set to the value of the hard heap limit. 6739 ** ^The soft heap limit is automatically enabled whenever the hard heap 6740 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6741 ** the soft heap limit is outside the range of 1..N, then the soft heap 6742 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6743 ** hard heap limit is enabled makes the soft heap limit equal to the 6744 ** hard heap limit. 6745 ** 6746 ** The memory allocation limits can also be adjusted using 6747 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6748 ** 6749 ** ^(The heap limits are not enforced in the current implementation 6750 ** if one or more of following conditions are true: 6751 ** 6752 ** <ul> 6753 ** <li> The limit value is set to zero. 6754 ** <li> Memory accounting is disabled using a combination of the 6755 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6756 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6757 ** <li> An alternative page cache implementation is specified using 6758 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6759 ** <li> The page cache allocates from its own memory pool supplied 6760 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6761 ** from the heap. 6762 ** </ul>)^ 6763 ** 6764 ** The circumstances under which SQLite will enforce the heap limits may 6765 ** changes in future releases of SQLite. 6766 */ 6767 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6768 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6769 6770 /* 6771 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6772 ** DEPRECATED 6773 ** 6774 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6775 ** interface. This routine is provided for historical compatibility 6776 ** only. All new applications should use the 6777 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6778 */ 6779 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6780 6781 6782 /* 6783 ** CAPI3REF: Extract Metadata About A Column Of A Table 6784 ** METHOD: sqlite3 6785 ** 6786 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6787 ** information about column C of table T in database D 6788 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6789 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6790 ** the final five arguments with appropriate values if the specified 6791 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6792 ** SQLITE_ERROR if the specified column does not exist. 6793 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6794 ** NULL pointer, then this routine simply checks for the existence of the 6795 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6796 ** does not. If the table name parameter T in a call to 6797 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6798 ** undefined behavior. 6799 ** 6800 ** ^The column is identified by the second, third and fourth parameters to 6801 ** this function. ^(The second parameter is either the name of the database 6802 ** (i.e. "main", "temp", or an attached database) containing the specified 6803 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6804 ** for the table using the same algorithm used by the database engine to 6805 ** resolve unqualified table references. 6806 ** 6807 ** ^The third and fourth parameters to this function are the table and column 6808 ** name of the desired column, respectively. 6809 ** 6810 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6811 ** and subsequent parameters to this function. ^Any of these arguments may be 6812 ** NULL, in which case the corresponding element of metadata is omitted. 6813 ** 6814 ** ^(<blockquote> 6815 ** <table border="1"> 6816 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6817 ** 6818 ** <tr><td> 5th <td> const char* <td> Data type 6819 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6820 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6821 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6822 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6823 ** </table> 6824 ** </blockquote>)^ 6825 ** 6826 ** ^The memory pointed to by the character pointers returned for the 6827 ** declaration type and collation sequence is valid until the next 6828 ** call to any SQLite API function. 6829 ** 6830 ** ^If the specified table is actually a view, an [error code] is returned. 6831 ** 6832 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6833 ** is not a [WITHOUT ROWID] table and an 6834 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6835 ** parameters are set for the explicitly declared column. ^(If there is no 6836 ** [INTEGER PRIMARY KEY] column, then the outputs 6837 ** for the [rowid] are set as follows: 6838 ** 6839 ** <pre> 6840 ** data type: "INTEGER" 6841 ** collation sequence: "BINARY" 6842 ** not null: 0 6843 ** primary key: 1 6844 ** auto increment: 0 6845 ** </pre>)^ 6846 ** 6847 ** ^This function causes all database schemas to be read from disk and 6848 ** parsed, if that has not already been done, and returns an error if 6849 ** any errors are encountered while loading the schema. 6850 */ 6851 SQLITE_API int sqlite3_table_column_metadata( 6852 sqlite3 *db, /* Connection handle */ 6853 const char *zDbName, /* Database name or NULL */ 6854 const char *zTableName, /* Table name */ 6855 const char *zColumnName, /* Column name */ 6856 char const **pzDataType, /* OUTPUT: Declared data type */ 6857 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6858 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6859 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6860 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6861 ); 6862 6863 /* 6864 ** CAPI3REF: Load An Extension 6865 ** METHOD: sqlite3 6866 ** 6867 ** ^This interface loads an SQLite extension library from the named file. 6868 ** 6869 ** ^The sqlite3_load_extension() interface attempts to load an 6870 ** [SQLite extension] library contained in the file zFile. If 6871 ** the file cannot be loaded directly, attempts are made to load 6872 ** with various operating-system specific extensions added. 6873 ** So for example, if "samplelib" cannot be loaded, then names like 6874 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6875 ** be tried also. 6876 ** 6877 ** ^The entry point is zProc. 6878 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6879 ** entry point name on its own. It first tries "sqlite3_extension_init". 6880 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6881 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6882 ** characters in the filename from the last "/" to the first following 6883 ** "." and omitting any initial "lib".)^ 6884 ** ^The sqlite3_load_extension() interface returns 6885 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6886 ** ^If an error occurs and pzErrMsg is not 0, then the 6887 ** [sqlite3_load_extension()] interface shall attempt to 6888 ** fill *pzErrMsg with error message text stored in memory 6889 ** obtained from [sqlite3_malloc()]. The calling function 6890 ** should free this memory by calling [sqlite3_free()]. 6891 ** 6892 ** ^Extension loading must be enabled using 6893 ** [sqlite3_enable_load_extension()] or 6894 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6895 ** prior to calling this API, 6896 ** otherwise an error will be returned. 6897 ** 6898 ** <b>Security warning:</b> It is recommended that the 6899 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6900 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6901 ** should be avoided. This will keep the SQL function [load_extension()] 6902 ** disabled and prevent SQL injections from giving attackers 6903 ** access to extension loading capabilities. 6904 ** 6905 ** See also the [load_extension() SQL function]. 6906 */ 6907 SQLITE_API int sqlite3_load_extension( 6908 sqlite3 *db, /* Load the extension into this database connection */ 6909 const char *zFile, /* Name of the shared library containing extension */ 6910 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6911 char **pzErrMsg /* Put error message here if not 0 */ 6912 ); 6913 6914 /* 6915 ** CAPI3REF: Enable Or Disable Extension Loading 6916 ** METHOD: sqlite3 6917 ** 6918 ** ^So as not to open security holes in older applications that are 6919 ** unprepared to deal with [extension loading], and as a means of disabling 6920 ** [extension loading] while evaluating user-entered SQL, the following API 6921 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6922 ** 6923 ** ^Extension loading is off by default. 6924 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6925 ** to turn extension loading on and call it with onoff==0 to turn 6926 ** it back off again. 6927 ** 6928 ** ^This interface enables or disables both the C-API 6929 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6930 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6931 ** to enable or disable only the C-API.)^ 6932 ** 6933 ** <b>Security warning:</b> It is recommended that extension loading 6934 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6935 ** rather than this interface, so the [load_extension()] SQL function 6936 ** remains disabled. This will prevent SQL injections from giving attackers 6937 ** access to extension loading capabilities. 6938 */ 6939 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6940 6941 /* 6942 ** CAPI3REF: Automatically Load Statically Linked Extensions 6943 ** 6944 ** ^This interface causes the xEntryPoint() function to be invoked for 6945 ** each new [database connection] that is created. The idea here is that 6946 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6947 ** that is to be automatically loaded into all new database connections. 6948 ** 6949 ** ^(Even though the function prototype shows that xEntryPoint() takes 6950 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6951 ** arguments and expects an integer result as if the signature of the 6952 ** entry point where as follows: 6953 ** 6954 ** <blockquote><pre> 6955 ** int xEntryPoint( 6956 ** sqlite3 *db, 6957 ** const char **pzErrMsg, 6958 ** const struct sqlite3_api_routines *pThunk 6959 ** ); 6960 ** </pre></blockquote>)^ 6961 ** 6962 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6963 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6964 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6965 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6966 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6967 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6968 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6969 ** 6970 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6971 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6972 ** will be called more than once for each database connection that is opened. 6973 ** 6974 ** See also: [sqlite3_reset_auto_extension()] 6975 ** and [sqlite3_cancel_auto_extension()] 6976 */ 6977 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6978 6979 /* 6980 ** CAPI3REF: Cancel Automatic Extension Loading 6981 ** 6982 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6983 ** initialization routine X that was registered using a prior call to 6984 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6985 ** routine returns 1 if initialization routine X was successfully 6986 ** unregistered and it returns 0 if X was not on the list of initialization 6987 ** routines. 6988 */ 6989 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6990 6991 /* 6992 ** CAPI3REF: Reset Automatic Extension Loading 6993 ** 6994 ** ^This interface disables all automatic extensions previously 6995 ** registered using [sqlite3_auto_extension()]. 6996 */ 6997 SQLITE_API void sqlite3_reset_auto_extension(void); 6998 6999 /* 7000 ** The interface to the virtual-table mechanism is currently considered 7001 ** to be experimental. The interface might change in incompatible ways. 7002 ** If this is a problem for you, do not use the interface at this time. 7003 ** 7004 ** When the virtual-table mechanism stabilizes, we will declare the 7005 ** interface fixed, support it indefinitely, and remove this comment. 7006 */ 7007 7008 /* 7009 ** Structures used by the virtual table interface 7010 */ 7011 typedef struct sqlite3_vtab sqlite3_vtab; 7012 typedef struct sqlite3_index_info sqlite3_index_info; 7013 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 7014 typedef struct sqlite3_module sqlite3_module; 7015 7016 /* 7017 ** CAPI3REF: Virtual Table Object 7018 ** KEYWORDS: sqlite3_module {virtual table module} 7019 ** 7020 ** This structure, sometimes called a "virtual table module", 7021 ** defines the implementation of a [virtual table]. 7022 ** This structure consists mostly of methods for the module. 7023 ** 7024 ** ^A virtual table module is created by filling in a persistent 7025 ** instance of this structure and passing a pointer to that instance 7026 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 7027 ** ^The registration remains valid until it is replaced by a different 7028 ** module or until the [database connection] closes. The content 7029 ** of this structure must not change while it is registered with 7030 ** any database connection. 7031 */ 7032 struct sqlite3_module { 7033 int iVersion; 7034 int (*xCreate)(sqlite3*, void *pAux, 7035 int argc, const char *const*argv, 7036 sqlite3_vtab **ppVTab, char**); 7037 int (*xConnect)(sqlite3*, void *pAux, 7038 int argc, const char *const*argv, 7039 sqlite3_vtab **ppVTab, char**); 7040 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 7041 int (*xDisconnect)(sqlite3_vtab *pVTab); 7042 int (*xDestroy)(sqlite3_vtab *pVTab); 7043 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 7044 int (*xClose)(sqlite3_vtab_cursor*); 7045 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 7046 int argc, sqlite3_value **argv); 7047 int (*xNext)(sqlite3_vtab_cursor*); 7048 int (*xEof)(sqlite3_vtab_cursor*); 7049 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 7050 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7051 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7052 int (*xBegin)(sqlite3_vtab *pVTab); 7053 int (*xSync)(sqlite3_vtab *pVTab); 7054 int (*xCommit)(sqlite3_vtab *pVTab); 7055 int (*xRollback)(sqlite3_vtab *pVTab); 7056 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7057 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7058 void **ppArg); 7059 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7060 /* The methods above are in version 1 of the sqlite_module object. Those 7061 ** below are for version 2 and greater. */ 7062 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7063 int (*xRelease)(sqlite3_vtab *pVTab, int); 7064 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7065 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7066 ** Those below are for version 3 and greater. */ 7067 int (*xShadowName)(const char*); 7068 }; 7069 7070 /* 7071 ** CAPI3REF: Virtual Table Indexing Information 7072 ** KEYWORDS: sqlite3_index_info 7073 ** 7074 ** The sqlite3_index_info structure and its substructures is used as part 7075 ** of the [virtual table] interface to 7076 ** pass information into and receive the reply from the [xBestIndex] 7077 ** method of a [virtual table module]. The fields under **Inputs** are the 7078 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 7079 ** results into the **Outputs** fields. 7080 ** 7081 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 7082 ** 7083 ** <blockquote>column OP expr</blockquote> 7084 ** 7085 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7086 ** stored in aConstraint[].op using one of the 7087 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7088 ** ^(The index of the column is stored in 7089 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7090 ** expr on the right-hand side can be evaluated (and thus the constraint 7091 ** is usable) and false if it cannot.)^ 7092 ** 7093 ** ^The optimizer automatically inverts terms of the form "expr OP column" 7094 ** and makes other simplifications to the WHERE clause in an attempt to 7095 ** get as many WHERE clause terms into the form shown above as possible. 7096 ** ^The aConstraint[] array only reports WHERE clause terms that are 7097 ** relevant to the particular virtual table being queried. 7098 ** 7099 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7100 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 7101 ** 7102 ** The colUsed field indicates which columns of the virtual table may be 7103 ** required by the current scan. Virtual table columns are numbered from 7104 ** zero in the order in which they appear within the CREATE TABLE statement 7105 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7106 ** the corresponding bit is set within the colUsed mask if the column may be 7107 ** required by SQLite. If the table has at least 64 columns and any column 7108 ** to the right of the first 63 is required, then bit 63 of colUsed is also 7109 ** set. In other words, column iCol may be required if the expression 7110 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7111 ** non-zero. 7112 ** 7113 ** The [xBestIndex] method must fill aConstraintUsage[] with information 7114 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 7115 ** the right-hand side of the corresponding aConstraint[] is evaluated 7116 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7117 ** is true, then the constraint is assumed to be fully handled by the 7118 ** virtual table and might not be checked again by the byte code.)^ ^(The 7119 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7120 ** is left in its default setting of false, the constraint will always be 7121 ** checked separately in byte code. If the omit flag is change to true, then 7122 ** the constraint may or may not be checked in byte code. In other words, 7123 ** when the omit flag is true there is no guarantee that the constraint will 7124 ** not be checked again using byte code.)^ 7125 ** 7126 ** ^The idxNum and idxPtr values are recorded and passed into the 7127 ** [xFilter] method. 7128 ** ^[sqlite3_free()] is used to free idxPtr if and only if 7129 ** needToFreeIdxPtr is true. 7130 ** 7131 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7132 ** the correct order to satisfy the ORDER BY clause so that no separate 7133 ** sorting step is required. 7134 ** 7135 ** ^The estimatedCost value is an estimate of the cost of a particular 7136 ** strategy. A cost of N indicates that the cost of the strategy is similar 7137 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 7138 ** indicates that the expense of the operation is similar to that of a 7139 ** binary search on a unique indexed field of an SQLite table with N rows. 7140 ** 7141 ** ^The estimatedRows value is an estimate of the number of rows that 7142 ** will be returned by the strategy. 7143 ** 7144 ** The xBestIndex method may optionally populate the idxFlags field with a 7145 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 7146 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 7147 ** assumes that the strategy may visit at most one row. 7148 ** 7149 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7150 ** SQLite also assumes that if a call to the xUpdate() method is made as 7151 ** part of the same statement to delete or update a virtual table row and the 7152 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7153 ** any database changes. In other words, if the xUpdate() returns 7154 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7155 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7156 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7157 ** the xUpdate method are automatically rolled back by SQLite. 7158 ** 7159 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7160 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7161 ** If a virtual table extension is 7162 ** used with an SQLite version earlier than 3.8.2, the results of attempting 7163 ** to read or write the estimatedRows field are undefined (but are likely 7164 ** to include crashing the application). The estimatedRows field should 7165 ** therefore only be used if [sqlite3_libversion_number()] returns a 7166 ** value greater than or equal to 3008002. Similarly, the idxFlags field 7167 ** was added for [version 3.9.0] ([dateof:3.9.0]). 7168 ** It may therefore only be used if 7169 ** sqlite3_libversion_number() returns a value greater than or equal to 7170 ** 3009000. 7171 */ 7172 struct sqlite3_index_info { 7173 /* Inputs */ 7174 int nConstraint; /* Number of entries in aConstraint */ 7175 struct sqlite3_index_constraint { 7176 int iColumn; /* Column constrained. -1 for ROWID */ 7177 unsigned char op; /* Constraint operator */ 7178 unsigned char usable; /* True if this constraint is usable */ 7179 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7180 } *aConstraint; /* Table of WHERE clause constraints */ 7181 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7182 struct sqlite3_index_orderby { 7183 int iColumn; /* Column number */ 7184 unsigned char desc; /* True for DESC. False for ASC. */ 7185 } *aOrderBy; /* The ORDER BY clause */ 7186 /* Outputs */ 7187 struct sqlite3_index_constraint_usage { 7188 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7189 unsigned char omit; /* Do not code a test for this constraint */ 7190 } *aConstraintUsage; 7191 int idxNum; /* Number used to identify the index */ 7192 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7193 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7194 int orderByConsumed; /* True if output is already ordered */ 7195 double estimatedCost; /* Estimated cost of using this index */ 7196 /* Fields below are only available in SQLite 3.8.2 and later */ 7197 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7198 /* Fields below are only available in SQLite 3.9.0 and later */ 7199 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7200 /* Fields below are only available in SQLite 3.10.0 and later */ 7201 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7202 }; 7203 7204 /* 7205 ** CAPI3REF: Virtual Table Scan Flags 7206 ** 7207 ** Virtual table implementations are allowed to set the 7208 ** [sqlite3_index_info].idxFlags field to some combination of 7209 ** these bits. 7210 */ 7211 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7212 7213 /* 7214 ** CAPI3REF: Virtual Table Constraint Operator Codes 7215 ** 7216 ** These macros define the allowed values for the 7217 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 7218 ** an operator that is part of a constraint term in the WHERE clause of 7219 ** a query that uses a [virtual table]. 7220 ** 7221 ** ^The left-hand operand of the operator is given by the corresponding 7222 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7223 ** operand is the rowid. 7224 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7225 ** operators have no left-hand operand, and so for those operators the 7226 ** corresponding aConstraint[].iColumn is meaningless and should not be 7227 ** used. 7228 ** 7229 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7230 ** value 255 are reserved to represent functions that are overloaded 7231 ** by the [xFindFunction|xFindFunction method] of the virtual table 7232 ** implementation. 7233 ** 7234 ** The right-hand operands for each constraint might be accessible using 7235 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7236 ** operand is only available if it appears as a single constant literal 7237 ** in the input SQL. If the right-hand operand is another column or an 7238 ** expression (even a constant expression) or a parameter, then the 7239 ** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7240 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7241 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7242 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7243 ** always return SQLITE_NOTFOUND. 7244 ** 7245 ** The collating sequence to be used for comparison can be found using 7246 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7247 ** tables, the collating sequence of constraints does not matter (for example 7248 ** because the constraints are numeric) and so the sqlite3_vtab_collation() 7249 ** interface is no commonly needed. 7250 */ 7251 #define SQLITE_INDEX_CONSTRAINT_EQ 2 7252 #define SQLITE_INDEX_CONSTRAINT_GT 4 7253 #define SQLITE_INDEX_CONSTRAINT_LE 8 7254 #define SQLITE_INDEX_CONSTRAINT_LT 16 7255 #define SQLITE_INDEX_CONSTRAINT_GE 32 7256 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7257 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7258 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7259 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7260 #define SQLITE_INDEX_CONSTRAINT_NE 68 7261 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7262 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7263 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7264 #define SQLITE_INDEX_CONSTRAINT_IS 72 7265 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7266 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7267 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7268 7269 /* 7270 ** CAPI3REF: Register A Virtual Table Implementation 7271 ** METHOD: sqlite3 7272 ** 7273 ** ^These routines are used to register a new [virtual table module] name. 7274 ** ^Module names must be registered before 7275 ** creating a new [virtual table] using the module and before using a 7276 ** preexisting [virtual table] for the module. 7277 ** 7278 ** ^The module name is registered on the [database connection] specified 7279 ** by the first parameter. ^The name of the module is given by the 7280 ** second parameter. ^The third parameter is a pointer to 7281 ** the implementation of the [virtual table module]. ^The fourth 7282 ** parameter is an arbitrary client data pointer that is passed through 7283 ** into the [xCreate] and [xConnect] methods of the virtual table module 7284 ** when a new virtual table is be being created or reinitialized. 7285 ** 7286 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7287 ** is a pointer to a destructor for the pClientData. ^SQLite will 7288 ** invoke the destructor function (if it is not NULL) when SQLite 7289 ** no longer needs the pClientData pointer. ^The destructor will also 7290 ** be invoked if the call to sqlite3_create_module_v2() fails. 7291 ** ^The sqlite3_create_module() 7292 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7293 ** destructor. 7294 ** 7295 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7296 ** NULL then no new module is created and any existing modules with the 7297 ** same name are dropped. 7298 ** 7299 ** See also: [sqlite3_drop_modules()] 7300 */ 7301 SQLITE_API int sqlite3_create_module( 7302 sqlite3 *db, /* SQLite connection to register module with */ 7303 const char *zName, /* Name of the module */ 7304 const sqlite3_module *p, /* Methods for the module */ 7305 void *pClientData /* Client data for xCreate/xConnect */ 7306 ); 7307 SQLITE_API int sqlite3_create_module_v2( 7308 sqlite3 *db, /* SQLite connection to register module with */ 7309 const char *zName, /* Name of the module */ 7310 const sqlite3_module *p, /* Methods for the module */ 7311 void *pClientData, /* Client data for xCreate/xConnect */ 7312 void(*xDestroy)(void*) /* Module destructor function */ 7313 ); 7314 7315 /* 7316 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7317 ** METHOD: sqlite3 7318 ** 7319 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7320 ** table modules from database connection D except those named on list L. 7321 ** The L parameter must be either NULL or a pointer to an array of pointers 7322 ** to strings where the array is terminated by a single NULL pointer. 7323 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7324 ** 7325 ** See also: [sqlite3_create_module()] 7326 */ 7327 SQLITE_API int sqlite3_drop_modules( 7328 sqlite3 *db, /* Remove modules from this connection */ 7329 const char **azKeep /* Except, do not remove the ones named here */ 7330 ); 7331 7332 /* 7333 ** CAPI3REF: Virtual Table Instance Object 7334 ** KEYWORDS: sqlite3_vtab 7335 ** 7336 ** Every [virtual table module] implementation uses a subclass 7337 ** of this object to describe a particular instance 7338 ** of the [virtual table]. Each subclass will 7339 ** be tailored to the specific needs of the module implementation. 7340 ** The purpose of this superclass is to define certain fields that are 7341 ** common to all module implementations. 7342 ** 7343 ** ^Virtual tables methods can set an error message by assigning a 7344 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7345 ** take care that any prior string is freed by a call to [sqlite3_free()] 7346 ** prior to assigning a new string to zErrMsg. ^After the error message 7347 ** is delivered up to the client application, the string will be automatically 7348 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7349 */ 7350 struct sqlite3_vtab { 7351 const sqlite3_module *pModule; /* The module for this virtual table */ 7352 int nRef; /* Number of open cursors */ 7353 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7354 /* Virtual table implementations will typically add additional fields */ 7355 }; 7356 7357 /* 7358 ** CAPI3REF: Virtual Table Cursor Object 7359 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7360 ** 7361 ** Every [virtual table module] implementation uses a subclass of the 7362 ** following structure to describe cursors that point into the 7363 ** [virtual table] and are used 7364 ** to loop through the virtual table. Cursors are created using the 7365 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7366 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7367 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7368 ** of the module. Each module implementation will define 7369 ** the content of a cursor structure to suit its own needs. 7370 ** 7371 ** This superclass exists in order to define fields of the cursor that 7372 ** are common to all implementations. 7373 */ 7374 struct sqlite3_vtab_cursor { 7375 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7376 /* Virtual table implementations will typically add additional fields */ 7377 }; 7378 7379 /* 7380 ** CAPI3REF: Declare The Schema Of A Virtual Table 7381 ** 7382 ** ^The [xCreate] and [xConnect] methods of a 7383 ** [virtual table module] call this interface 7384 ** to declare the format (the names and datatypes of the columns) of 7385 ** the virtual tables they implement. 7386 */ 7387 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7388 7389 /* 7390 ** CAPI3REF: Overload A Function For A Virtual Table 7391 ** METHOD: sqlite3 7392 ** 7393 ** ^(Virtual tables can provide alternative implementations of functions 7394 ** using the [xFindFunction] method of the [virtual table module]. 7395 ** But global versions of those functions 7396 ** must exist in order to be overloaded.)^ 7397 ** 7398 ** ^(This API makes sure a global version of a function with a particular 7399 ** name and number of parameters exists. If no such function exists 7400 ** before this API is called, a new function is created.)^ ^The implementation 7401 ** of the new function always causes an exception to be thrown. So 7402 ** the new function is not good for anything by itself. Its only 7403 ** purpose is to be a placeholder function that can be overloaded 7404 ** by a [virtual table]. 7405 */ 7406 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7407 7408 /* 7409 ** The interface to the virtual-table mechanism defined above (back up 7410 ** to a comment remarkably similar to this one) is currently considered 7411 ** to be experimental. The interface might change in incompatible ways. 7412 ** If this is a problem for you, do not use the interface at this time. 7413 ** 7414 ** When the virtual-table mechanism stabilizes, we will declare the 7415 ** interface fixed, support it indefinitely, and remove this comment. 7416 */ 7417 7418 /* 7419 ** CAPI3REF: A Handle To An Open BLOB 7420 ** KEYWORDS: {BLOB handle} {BLOB handles} 7421 ** 7422 ** An instance of this object represents an open BLOB on which 7423 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7424 ** ^Objects of this type are created by [sqlite3_blob_open()] 7425 ** and destroyed by [sqlite3_blob_close()]. 7426 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7427 ** can be used to read or write small subsections of the BLOB. 7428 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7429 */ 7430 typedef struct sqlite3_blob sqlite3_blob; 7431 7432 /* 7433 ** CAPI3REF: Open A BLOB For Incremental I/O 7434 ** METHOD: sqlite3 7435 ** CONSTRUCTOR: sqlite3_blob 7436 ** 7437 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7438 ** in row iRow, column zColumn, table zTable in database zDb; 7439 ** in other words, the same BLOB that would be selected by: 7440 ** 7441 ** <pre> 7442 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7443 ** </pre>)^ 7444 ** 7445 ** ^(Parameter zDb is not the filename that contains the database, but 7446 ** rather the symbolic name of the database. For attached databases, this is 7447 ** the name that appears after the AS keyword in the [ATTACH] statement. 7448 ** For the main database file, the database name is "main". For TEMP 7449 ** tables, the database name is "temp".)^ 7450 ** 7451 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7452 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7453 ** read-only access. 7454 ** 7455 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7456 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7457 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7458 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7459 ** on *ppBlob after this function it returns. 7460 ** 7461 ** This function fails with SQLITE_ERROR if any of the following are true: 7462 ** <ul> 7463 ** <li> ^(Database zDb does not exist)^, 7464 ** <li> ^(Table zTable does not exist within database zDb)^, 7465 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7466 ** <li> ^(Column zColumn does not exist)^, 7467 ** <li> ^(Row iRow is not present in the table)^, 7468 ** <li> ^(The specified column of row iRow contains a value that is not 7469 ** a TEXT or BLOB value)^, 7470 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7471 ** constraint and the blob is being opened for read/write access)^, 7472 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7473 ** column zColumn is part of a [child key] definition and the blob is 7474 ** being opened for read/write access)^. 7475 ** </ul> 7476 ** 7477 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7478 ** [database connection] error code and message accessible via 7479 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7480 ** 7481 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7482 ** [sqlite3_blob_read()] interface and modified by using 7483 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7484 ** different row of the same table using the [sqlite3_blob_reopen()] 7485 ** interface. However, the column, table, or database of a [BLOB handle] 7486 ** cannot be changed after the [BLOB handle] is opened. 7487 ** 7488 ** ^(If the row that a BLOB handle points to is modified by an 7489 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7490 ** then the BLOB handle is marked as "expired". 7491 ** This is true if any column of the row is changed, even a column 7492 ** other than the one the BLOB handle is open on.)^ 7493 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7494 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7495 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7496 ** rolled back by the expiration of the BLOB. Such changes will eventually 7497 ** commit if the transaction continues to completion.)^ 7498 ** 7499 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7500 ** the opened blob. ^The size of a blob may not be changed by this 7501 ** interface. Use the [UPDATE] SQL command to change the size of a 7502 ** blob. 7503 ** 7504 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7505 ** and the built-in [zeroblob] SQL function may be used to create a 7506 ** zero-filled blob to read or write using the incremental-blob interface. 7507 ** 7508 ** To avoid a resource leak, every open [BLOB handle] should eventually 7509 ** be released by a call to [sqlite3_blob_close()]. 7510 ** 7511 ** See also: [sqlite3_blob_close()], 7512 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7513 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7514 */ 7515 SQLITE_API int sqlite3_blob_open( 7516 sqlite3*, 7517 const char *zDb, 7518 const char *zTable, 7519 const char *zColumn, 7520 sqlite3_int64 iRow, 7521 int flags, 7522 sqlite3_blob **ppBlob 7523 ); 7524 7525 /* 7526 ** CAPI3REF: Move a BLOB Handle to a New Row 7527 ** METHOD: sqlite3_blob 7528 ** 7529 ** ^This function is used to move an existing [BLOB handle] so that it points 7530 ** to a different row of the same database table. ^The new row is identified 7531 ** by the rowid value passed as the second argument. Only the row can be 7532 ** changed. ^The database, table and column on which the blob handle is open 7533 ** remain the same. Moving an existing [BLOB handle] to a new row is 7534 ** faster than closing the existing handle and opening a new one. 7535 ** 7536 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7537 ** it must exist and there must be either a blob or text value stored in 7538 ** the nominated column.)^ ^If the new row is not present in the table, or if 7539 ** it does not contain a blob or text value, or if another error occurs, an 7540 ** SQLite error code is returned and the blob handle is considered aborted. 7541 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7542 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7543 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7544 ** always returns zero. 7545 ** 7546 ** ^This function sets the database handle error code and message. 7547 */ 7548 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7549 7550 /* 7551 ** CAPI3REF: Close A BLOB Handle 7552 ** DESTRUCTOR: sqlite3_blob 7553 ** 7554 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7555 ** unconditionally. Even if this routine returns an error code, the 7556 ** handle is still closed.)^ 7557 ** 7558 ** ^If the blob handle being closed was opened for read-write access, and if 7559 ** the database is in auto-commit mode and there are no other open read-write 7560 ** blob handles or active write statements, the current transaction is 7561 ** committed. ^If an error occurs while committing the transaction, an error 7562 ** code is returned and the transaction rolled back. 7563 ** 7564 ** Calling this function with an argument that is not a NULL pointer or an 7565 ** open blob handle results in undefined behaviour. ^Calling this routine 7566 ** with a null pointer (such as would be returned by a failed call to 7567 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7568 ** is passed a valid open blob handle, the values returned by the 7569 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7570 */ 7571 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7572 7573 /* 7574 ** CAPI3REF: Return The Size Of An Open BLOB 7575 ** METHOD: sqlite3_blob 7576 ** 7577 ** ^Returns the size in bytes of the BLOB accessible via the 7578 ** successfully opened [BLOB handle] in its only argument. ^The 7579 ** incremental blob I/O routines can only read or overwriting existing 7580 ** blob content; they cannot change the size of a blob. 7581 ** 7582 ** This routine only works on a [BLOB handle] which has been created 7583 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7584 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7585 ** to this routine results in undefined and probably undesirable behavior. 7586 */ 7587 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7588 7589 /* 7590 ** CAPI3REF: Read Data From A BLOB Incrementally 7591 ** METHOD: sqlite3_blob 7592 ** 7593 ** ^(This function is used to read data from an open [BLOB handle] into a 7594 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7595 ** from the open BLOB, starting at offset iOffset.)^ 7596 ** 7597 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7598 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7599 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7600 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7601 ** can be determined using the [sqlite3_blob_bytes()] interface. 7602 ** 7603 ** ^An attempt to read from an expired [BLOB handle] fails with an 7604 ** error code of [SQLITE_ABORT]. 7605 ** 7606 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7607 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7608 ** 7609 ** This routine only works on a [BLOB handle] which has been created 7610 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7611 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7612 ** to this routine results in undefined and probably undesirable behavior. 7613 ** 7614 ** See also: [sqlite3_blob_write()]. 7615 */ 7616 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7617 7618 /* 7619 ** CAPI3REF: Write Data Into A BLOB Incrementally 7620 ** METHOD: sqlite3_blob 7621 ** 7622 ** ^(This function is used to write data into an open [BLOB handle] from a 7623 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7624 ** into the open BLOB, starting at offset iOffset.)^ 7625 ** 7626 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7627 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7628 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7629 ** [database connection] error code and message accessible via 7630 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7631 ** 7632 ** ^If the [BLOB handle] passed as the first argument was not opened for 7633 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7634 ** this function returns [SQLITE_READONLY]. 7635 ** 7636 ** This function may only modify the contents of the BLOB; it is 7637 ** not possible to increase the size of a BLOB using this API. 7638 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7639 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7640 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7641 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7642 ** than zero [SQLITE_ERROR] is returned and no data is written. 7643 ** 7644 ** ^An attempt to write to an expired [BLOB handle] fails with an 7645 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7646 ** before the [BLOB handle] expired are not rolled back by the 7647 ** expiration of the handle, though of course those changes might 7648 ** have been overwritten by the statement that expired the BLOB handle 7649 ** or by other independent statements. 7650 ** 7651 ** This routine only works on a [BLOB handle] which has been created 7652 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7653 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7654 ** to this routine results in undefined and probably undesirable behavior. 7655 ** 7656 ** See also: [sqlite3_blob_read()]. 7657 */ 7658 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7659 7660 /* 7661 ** CAPI3REF: Virtual File System Objects 7662 ** 7663 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7664 ** that SQLite uses to interact 7665 ** with the underlying operating system. Most SQLite builds come with a 7666 ** single default VFS that is appropriate for the host computer. 7667 ** New VFSes can be registered and existing VFSes can be unregistered. 7668 ** The following interfaces are provided. 7669 ** 7670 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7671 ** ^Names are case sensitive. 7672 ** ^Names are zero-terminated UTF-8 strings. 7673 ** ^If there is no match, a NULL pointer is returned. 7674 ** ^If zVfsName is NULL then the default VFS is returned. 7675 ** 7676 ** ^New VFSes are registered with sqlite3_vfs_register(). 7677 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7678 ** ^The same VFS can be registered multiple times without injury. 7679 ** ^To make an existing VFS into the default VFS, register it again 7680 ** with the makeDflt flag set. If two different VFSes with the 7681 ** same name are registered, the behavior is undefined. If a 7682 ** VFS is registered with a name that is NULL or an empty string, 7683 ** then the behavior is undefined. 7684 ** 7685 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7686 ** ^(If the default VFS is unregistered, another VFS is chosen as 7687 ** the default. The choice for the new VFS is arbitrary.)^ 7688 */ 7689 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7690 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7691 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7692 7693 /* 7694 ** CAPI3REF: Mutexes 7695 ** 7696 ** The SQLite core uses these routines for thread 7697 ** synchronization. Though they are intended for internal 7698 ** use by SQLite, code that links against SQLite is 7699 ** permitted to use any of these routines. 7700 ** 7701 ** The SQLite source code contains multiple implementations 7702 ** of these mutex routines. An appropriate implementation 7703 ** is selected automatically at compile-time. The following 7704 ** implementations are available in the SQLite core: 7705 ** 7706 ** <ul> 7707 ** <li> SQLITE_MUTEX_PTHREADS 7708 ** <li> SQLITE_MUTEX_W32 7709 ** <li> SQLITE_MUTEX_NOOP 7710 ** </ul> 7711 ** 7712 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7713 ** that does no real locking and is appropriate for use in 7714 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7715 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7716 ** and Windows. 7717 ** 7718 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7719 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7720 ** implementation is included with the library. In this case the 7721 ** application must supply a custom mutex implementation using the 7722 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7723 ** before calling sqlite3_initialize() or any other public sqlite3_ 7724 ** function that calls sqlite3_initialize(). 7725 ** 7726 ** ^The sqlite3_mutex_alloc() routine allocates a new 7727 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7728 ** routine returns NULL if it is unable to allocate the requested 7729 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7730 ** integer constants: 7731 ** 7732 ** <ul> 7733 ** <li> SQLITE_MUTEX_FAST 7734 ** <li> SQLITE_MUTEX_RECURSIVE 7735 ** <li> SQLITE_MUTEX_STATIC_MAIN 7736 ** <li> SQLITE_MUTEX_STATIC_MEM 7737 ** <li> SQLITE_MUTEX_STATIC_OPEN 7738 ** <li> SQLITE_MUTEX_STATIC_PRNG 7739 ** <li> SQLITE_MUTEX_STATIC_LRU 7740 ** <li> SQLITE_MUTEX_STATIC_PMEM 7741 ** <li> SQLITE_MUTEX_STATIC_APP1 7742 ** <li> SQLITE_MUTEX_STATIC_APP2 7743 ** <li> SQLITE_MUTEX_STATIC_APP3 7744 ** <li> SQLITE_MUTEX_STATIC_VFS1 7745 ** <li> SQLITE_MUTEX_STATIC_VFS2 7746 ** <li> SQLITE_MUTEX_STATIC_VFS3 7747 ** </ul> 7748 ** 7749 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7750 ** cause sqlite3_mutex_alloc() to create 7751 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7752 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7753 ** The mutex implementation does not need to make a distinction 7754 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7755 ** not want to. SQLite will only request a recursive mutex in 7756 ** cases where it really needs one. If a faster non-recursive mutex 7757 ** implementation is available on the host platform, the mutex subsystem 7758 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7759 ** 7760 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7761 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7762 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7763 ** used by the current version of SQLite. Future versions of SQLite 7764 ** may add additional static mutexes. Static mutexes are for internal 7765 ** use by SQLite only. Applications that use SQLite mutexes should 7766 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7767 ** SQLITE_MUTEX_RECURSIVE. 7768 ** 7769 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7770 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7771 ** returns a different mutex on every call. ^For the static 7772 ** mutex types, the same mutex is returned on every call that has 7773 ** the same type number. 7774 ** 7775 ** ^The sqlite3_mutex_free() routine deallocates a previously 7776 ** allocated dynamic mutex. Attempting to deallocate a static 7777 ** mutex results in undefined behavior. 7778 ** 7779 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7780 ** to enter a mutex. ^If another thread is already within the mutex, 7781 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7782 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7783 ** upon successful entry. ^(Mutexes created using 7784 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7785 ** In such cases, the 7786 ** mutex must be exited an equal number of times before another thread 7787 ** can enter.)^ If the same thread tries to enter any mutex other 7788 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7789 ** 7790 ** ^(Some systems (for example, Windows 95) do not support the operation 7791 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7792 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7793 ** sqlite3_mutex_try() as an optimization so this is acceptable 7794 ** behavior.)^ 7795 ** 7796 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7797 ** previously entered by the same thread. The behavior 7798 ** is undefined if the mutex is not currently entered by the 7799 ** calling thread or is not currently allocated. 7800 ** 7801 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7802 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7803 ** behave as no-ops. 7804 ** 7805 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7806 */ 7807 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7808 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7809 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7810 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7811 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7812 7813 /* 7814 ** CAPI3REF: Mutex Methods Object 7815 ** 7816 ** An instance of this structure defines the low-level routines 7817 ** used to allocate and use mutexes. 7818 ** 7819 ** Usually, the default mutex implementations provided by SQLite are 7820 ** sufficient, however the application has the option of substituting a custom 7821 ** implementation for specialized deployments or systems for which SQLite 7822 ** does not provide a suitable implementation. In this case, the application 7823 ** creates and populates an instance of this structure to pass 7824 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7825 ** Additionally, an instance of this structure can be used as an 7826 ** output variable when querying the system for the current mutex 7827 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7828 ** 7829 ** ^The xMutexInit method defined by this structure is invoked as 7830 ** part of system initialization by the sqlite3_initialize() function. 7831 ** ^The xMutexInit routine is called by SQLite exactly once for each 7832 ** effective call to [sqlite3_initialize()]. 7833 ** 7834 ** ^The xMutexEnd method defined by this structure is invoked as 7835 ** part of system shutdown by the sqlite3_shutdown() function. The 7836 ** implementation of this method is expected to release all outstanding 7837 ** resources obtained by the mutex methods implementation, especially 7838 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7839 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7840 ** 7841 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7842 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7843 ** xMutexNotheld) implement the following interfaces (respectively): 7844 ** 7845 ** <ul> 7846 ** <li> [sqlite3_mutex_alloc()] </li> 7847 ** <li> [sqlite3_mutex_free()] </li> 7848 ** <li> [sqlite3_mutex_enter()] </li> 7849 ** <li> [sqlite3_mutex_try()] </li> 7850 ** <li> [sqlite3_mutex_leave()] </li> 7851 ** <li> [sqlite3_mutex_held()] </li> 7852 ** <li> [sqlite3_mutex_notheld()] </li> 7853 ** </ul>)^ 7854 ** 7855 ** The only difference is that the public sqlite3_XXX functions enumerated 7856 ** above silently ignore any invocations that pass a NULL pointer instead 7857 ** of a valid mutex handle. The implementations of the methods defined 7858 ** by this structure are not required to handle this case. The results 7859 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7860 ** (i.e. it is acceptable to provide an implementation that segfaults if 7861 ** it is passed a NULL pointer). 7862 ** 7863 ** The xMutexInit() method must be threadsafe. It must be harmless to 7864 ** invoke xMutexInit() multiple times within the same process and without 7865 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7866 ** xMutexInit() must be no-ops. 7867 ** 7868 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7869 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7870 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7871 ** memory allocation for a fast or recursive mutex. 7872 ** 7873 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7874 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7875 ** If xMutexInit fails in any way, it is expected to clean up after itself 7876 ** prior to returning. 7877 */ 7878 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7879 struct sqlite3_mutex_methods { 7880 int (*xMutexInit)(void); 7881 int (*xMutexEnd)(void); 7882 sqlite3_mutex *(*xMutexAlloc)(int); 7883 void (*xMutexFree)(sqlite3_mutex *); 7884 void (*xMutexEnter)(sqlite3_mutex *); 7885 int (*xMutexTry)(sqlite3_mutex *); 7886 void (*xMutexLeave)(sqlite3_mutex *); 7887 int (*xMutexHeld)(sqlite3_mutex *); 7888 int (*xMutexNotheld)(sqlite3_mutex *); 7889 }; 7890 7891 /* 7892 ** CAPI3REF: Mutex Verification Routines 7893 ** 7894 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7895 ** are intended for use inside assert() statements. The SQLite core 7896 ** never uses these routines except inside an assert() and applications 7897 ** are advised to follow the lead of the core. The SQLite core only 7898 ** provides implementations for these routines when it is compiled 7899 ** with the SQLITE_DEBUG flag. External mutex implementations 7900 ** are only required to provide these routines if SQLITE_DEBUG is 7901 ** defined and if NDEBUG is not defined. 7902 ** 7903 ** These routines should return true if the mutex in their argument 7904 ** is held or not held, respectively, by the calling thread. 7905 ** 7906 ** The implementation is not required to provide versions of these 7907 ** routines that actually work. If the implementation does not provide working 7908 ** versions of these routines, it should at least provide stubs that always 7909 ** return true so that one does not get spurious assertion failures. 7910 ** 7911 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7912 ** the routine should return 1. This seems counter-intuitive since 7913 ** clearly the mutex cannot be held if it does not exist. But 7914 ** the reason the mutex does not exist is because the build is not 7915 ** using mutexes. And we do not want the assert() containing the 7916 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7917 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7918 ** interface should also return 1 when given a NULL pointer. 7919 */ 7920 #ifndef NDEBUG 7921 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7922 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7923 #endif 7924 7925 /* 7926 ** CAPI3REF: Mutex Types 7927 ** 7928 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7929 ** which is one of these integer constants. 7930 ** 7931 ** The set of static mutexes may change from one SQLite release to the 7932 ** next. Applications that override the built-in mutex logic must be 7933 ** prepared to accommodate additional static mutexes. 7934 */ 7935 #define SQLITE_MUTEX_FAST 0 7936 #define SQLITE_MUTEX_RECURSIVE 1 7937 #define SQLITE_MUTEX_STATIC_MAIN 2 7938 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7939 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7940 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7941 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7942 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7943 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7944 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7945 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7946 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7947 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7948 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7949 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7950 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7951 7952 /* Legacy compatibility: */ 7953 #define SQLITE_MUTEX_STATIC_MASTER 2 7954 7955 7956 /* 7957 ** CAPI3REF: Retrieve the mutex for a database connection 7958 ** METHOD: sqlite3 7959 ** 7960 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7961 ** serializes access to the [database connection] given in the argument 7962 ** when the [threading mode] is Serialized. 7963 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7964 ** routine returns a NULL pointer. 7965 */ 7966 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7967 7968 /* 7969 ** CAPI3REF: Low-Level Control Of Database Files 7970 ** METHOD: sqlite3 7971 ** KEYWORDS: {file control} 7972 ** 7973 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7974 ** xFileControl method for the [sqlite3_io_methods] object associated 7975 ** with a particular database identified by the second argument. ^The 7976 ** name of the database is "main" for the main database or "temp" for the 7977 ** TEMP database, or the name that appears after the AS keyword for 7978 ** databases that are added using the [ATTACH] SQL command. 7979 ** ^A NULL pointer can be used in place of "main" to refer to the 7980 ** main database file. 7981 ** ^The third and fourth parameters to this routine 7982 ** are passed directly through to the second and third parameters of 7983 ** the xFileControl method. ^The return value of the xFileControl 7984 ** method becomes the return value of this routine. 7985 ** 7986 ** A few opcodes for [sqlite3_file_control()] are handled directly 7987 ** by the SQLite core and never invoke the 7988 ** sqlite3_io_methods.xFileControl method. 7989 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7990 ** a pointer to the underlying [sqlite3_file] object to be written into 7991 ** the space pointed to by the 4th parameter. The 7992 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7993 ** the [sqlite3_file] object associated with the journal file instead of 7994 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7995 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7996 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7997 ** from the pager. 7998 ** 7999 ** ^If the second parameter (zDbName) does not match the name of any 8000 ** open database file, then SQLITE_ERROR is returned. ^This error 8001 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 8002 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 8003 ** also return SQLITE_ERROR. There is no way to distinguish between 8004 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 8005 ** xFileControl method. 8006 ** 8007 ** See also: [file control opcodes] 8008 */ 8009 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 8010 8011 /* 8012 ** CAPI3REF: Testing Interface 8013 ** 8014 ** ^The sqlite3_test_control() interface is used to read out internal 8015 ** state of SQLite and to inject faults into SQLite for testing 8016 ** purposes. ^The first parameter is an operation code that determines 8017 ** the number, meaning, and operation of all subsequent parameters. 8018 ** 8019 ** This interface is not for use by applications. It exists solely 8020 ** for verifying the correct operation of the SQLite library. Depending 8021 ** on how the SQLite library is compiled, this interface might not exist. 8022 ** 8023 ** The details of the operation codes, their meanings, the parameters 8024 ** they take, and what they do are all subject to change without notice. 8025 ** Unlike most of the SQLite API, this function is not guaranteed to 8026 ** operate consistently from one release to the next. 8027 */ 8028 SQLITE_API int sqlite3_test_control(int op, ...); 8029 8030 /* 8031 ** CAPI3REF: Testing Interface Operation Codes 8032 ** 8033 ** These constants are the valid operation code parameters used 8034 ** as the first argument to [sqlite3_test_control()]. 8035 ** 8036 ** These parameters and their meanings are subject to change 8037 ** without notice. These values are for testing purposes only. 8038 ** Applications should not use any of these parameters or the 8039 ** [sqlite3_test_control()] interface. 8040 */ 8041 #define SQLITE_TESTCTRL_FIRST 5 8042 #define SQLITE_TESTCTRL_PRNG_SAVE 5 8043 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 8044 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 8045 #define SQLITE_TESTCTRL_BITVEC_TEST 8 8046 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 8047 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 8048 #define SQLITE_TESTCTRL_PENDING_BYTE 11 8049 #define SQLITE_TESTCTRL_ASSERT 12 8050 #define SQLITE_TESTCTRL_ALWAYS 13 8051 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8052 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8053 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8054 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8055 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8056 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8057 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8058 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8059 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8060 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8061 #define SQLITE_TESTCTRL_BYTEORDER 22 8062 #define SQLITE_TESTCTRL_ISINIT 23 8063 #define SQLITE_TESTCTRL_SORTER_MMAP 24 8064 #define SQLITE_TESTCTRL_IMPOSTER 25 8065 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8066 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 8067 #define SQLITE_TESTCTRL_PRNG_SEED 28 8068 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8069 #define SQLITE_TESTCTRL_SEEK_COUNT 30 8070 #define SQLITE_TESTCTRL_TRACEFLAGS 31 8071 #define SQLITE_TESTCTRL_TUNE 32 8072 #define SQLITE_TESTCTRL_LOGEST 33 8073 #define SQLITE_TESTCTRL_LAST 33 /* Largest TESTCTRL */ 8074 8075 /* 8076 ** CAPI3REF: SQL Keyword Checking 8077 ** 8078 ** These routines provide access to the set of SQL language keywords 8079 ** recognized by SQLite. Applications can uses these routines to determine 8080 ** whether or not a specific identifier needs to be escaped (for example, 8081 ** by enclosing in double-quotes) so as not to confuse the parser. 8082 ** 8083 ** The sqlite3_keyword_count() interface returns the number of distinct 8084 ** keywords understood by SQLite. 8085 ** 8086 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 8087 ** makes *Z point to that keyword expressed as UTF8 and writes the number 8088 ** of bytes in the keyword into *L. The string that *Z points to is not 8089 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8090 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8091 ** or L are NULL or invalid pointers then calls to 8092 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8093 ** 8094 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8095 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8096 ** if it is and zero if not. 8097 ** 8098 ** The parser used by SQLite is forgiving. It is often possible to use 8099 ** a keyword as an identifier as long as such use does not result in a 8100 ** parsing ambiguity. For example, the statement 8101 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8102 ** creates a new table named "BEGIN" with three columns named 8103 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8104 ** using keywords as identifiers. Common techniques used to avoid keyword 8105 ** name collisions include: 8106 ** <ul> 8107 ** <li> Put all identifier names inside double-quotes. This is the official 8108 ** SQL way to escape identifier names. 8109 ** <li> Put identifier names inside [...]. This is not standard SQL, 8110 ** but it is what SQL Server does and so lots of programmers use this 8111 ** technique. 8112 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8113 ** with "Z". 8114 ** <li> Include a digit somewhere in every identifier name. 8115 ** </ul> 8116 ** 8117 ** Note that the number of keywords understood by SQLite can depend on 8118 ** compile-time options. For example, "VACUUM" is not a keyword if 8119 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8120 ** new keywords may be added to future releases of SQLite. 8121 */ 8122 SQLITE_API int sqlite3_keyword_count(void); 8123 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8124 SQLITE_API int sqlite3_keyword_check(const char*,int); 8125 8126 /* 8127 ** CAPI3REF: Dynamic String Object 8128 ** KEYWORDS: {dynamic string} 8129 ** 8130 ** An instance of the sqlite3_str object contains a dynamically-sized 8131 ** string under construction. 8132 ** 8133 ** The lifecycle of an sqlite3_str object is as follows: 8134 ** <ol> 8135 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8136 ** <li> ^Text is appended to the sqlite3_str object using various 8137 ** methods, such as [sqlite3_str_appendf()]. 8138 ** <li> ^The sqlite3_str object is destroyed and the string it created 8139 ** is returned using the [sqlite3_str_finish()] interface. 8140 ** </ol> 8141 */ 8142 typedef struct sqlite3_str sqlite3_str; 8143 8144 /* 8145 ** CAPI3REF: Create A New Dynamic String Object 8146 ** CONSTRUCTOR: sqlite3_str 8147 ** 8148 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 8149 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8150 ** [sqlite3_str_new()] must be freed by a subsequent call to 8151 ** [sqlite3_str_finish(X)]. 8152 ** 8153 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8154 ** valid [sqlite3_str] object, though in the event of an out-of-memory 8155 ** error the returned object might be a special singleton that will 8156 ** silently reject new text, always return SQLITE_NOMEM from 8157 ** [sqlite3_str_errcode()], always return 0 for 8158 ** [sqlite3_str_length()], and always return NULL from 8159 ** [sqlite3_str_finish(X)]. It is always safe to use the value 8160 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8161 ** to any of the other [sqlite3_str] methods. 8162 ** 8163 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8164 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8165 ** length of the string contained in the [sqlite3_str] object will be 8166 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8167 ** of [SQLITE_MAX_LENGTH]. 8168 */ 8169 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8170 8171 /* 8172 ** CAPI3REF: Finalize A Dynamic String 8173 ** DESTRUCTOR: sqlite3_str 8174 ** 8175 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8176 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8177 ** that contains the constructed string. The calling application should 8178 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8179 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8180 ** errors were encountered during construction of the string. ^The 8181 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8182 ** string in [sqlite3_str] object X is zero bytes long. 8183 */ 8184 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8185 8186 /* 8187 ** CAPI3REF: Add Content To A Dynamic String 8188 ** METHOD: sqlite3_str 8189 ** 8190 ** These interfaces add content to an sqlite3_str object previously obtained 8191 ** from [sqlite3_str_new()]. 8192 ** 8193 ** ^The [sqlite3_str_appendf(X,F,...)] and 8194 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8195 ** functionality of SQLite to append formatted text onto the end of 8196 ** [sqlite3_str] object X. 8197 ** 8198 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8199 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 8200 ** S must contain at least N non-zero bytes of content. To append a 8201 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8202 ** method instead. 8203 ** 8204 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8205 ** zero-terminated string S onto the end of [sqlite3_str] object X. 8206 ** 8207 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8208 ** single-byte character C onto the end of [sqlite3_str] object X. 8209 ** ^This method can be used, for example, to add whitespace indentation. 8210 ** 8211 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 8212 ** inside [sqlite3_str] object X back to zero bytes in length. 8213 ** 8214 ** These methods do not return a result code. ^If an error occurs, that fact 8215 ** is recorded in the [sqlite3_str] object and can be recovered by a 8216 ** subsequent call to [sqlite3_str_errcode(X)]. 8217 */ 8218 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8219 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8220 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8221 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8222 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8223 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8224 8225 /* 8226 ** CAPI3REF: Status Of A Dynamic String 8227 ** METHOD: sqlite3_str 8228 ** 8229 ** These interfaces return the current status of an [sqlite3_str] object. 8230 ** 8231 ** ^If any prior errors have occurred while constructing the dynamic string 8232 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8233 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8234 ** [SQLITE_NOMEM] following any out-of-memory error, or 8235 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8236 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8237 ** 8238 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8239 ** of the dynamic string under construction in [sqlite3_str] object X. 8240 ** ^The length returned by [sqlite3_str_length(X)] does not include the 8241 ** zero-termination byte. 8242 ** 8243 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8244 ** content of the dynamic string under construction in X. The value 8245 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8246 ** and might be freed or altered by any subsequent method on the same 8247 ** [sqlite3_str] object. Applications must not used the pointer returned 8248 ** [sqlite3_str_value(X)] after any subsequent method call on the same 8249 ** object. ^Applications may change the content of the string returned 8250 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8251 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8252 ** write any byte after any subsequent sqlite3_str method call. 8253 */ 8254 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8255 SQLITE_API int sqlite3_str_length(sqlite3_str*); 8256 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8257 8258 /* 8259 ** CAPI3REF: SQLite Runtime Status 8260 ** 8261 ** ^These interfaces are used to retrieve runtime status information 8262 ** about the performance of SQLite, and optionally to reset various 8263 ** highwater marks. ^The first argument is an integer code for 8264 ** the specific parameter to measure. ^(Recognized integer codes 8265 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8266 ** ^The current value of the parameter is returned into *pCurrent. 8267 ** ^The highest recorded value is returned in *pHighwater. ^If the 8268 ** resetFlag is true, then the highest record value is reset after 8269 ** *pHighwater is written. ^(Some parameters do not record the highest 8270 ** value. For those parameters 8271 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8272 ** ^(Other parameters record only the highwater mark and not the current 8273 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8274 ** 8275 ** ^The sqlite3_status() and sqlite3_status64() routines return 8276 ** SQLITE_OK on success and a non-zero [error code] on failure. 8277 ** 8278 ** If either the current value or the highwater mark is too large to 8279 ** be represented by a 32-bit integer, then the values returned by 8280 ** sqlite3_status() are undefined. 8281 ** 8282 ** See also: [sqlite3_db_status()] 8283 */ 8284 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8285 SQLITE_API int sqlite3_status64( 8286 int op, 8287 sqlite3_int64 *pCurrent, 8288 sqlite3_int64 *pHighwater, 8289 int resetFlag 8290 ); 8291 8292 8293 /* 8294 ** CAPI3REF: Status Parameters 8295 ** KEYWORDS: {status parameters} 8296 ** 8297 ** These integer constants designate various run-time status parameters 8298 ** that can be returned by [sqlite3_status()]. 8299 ** 8300 ** <dl> 8301 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8302 ** <dd>This parameter is the current amount of memory checked out 8303 ** using [sqlite3_malloc()], either directly or indirectly. The 8304 ** figure includes calls made to [sqlite3_malloc()] by the application 8305 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8306 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8307 ** this parameter. The amount returned is the sum of the allocation 8308 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8309 ** 8310 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8311 ** <dd>This parameter records the largest memory allocation request 8312 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8313 ** internal equivalents). Only the value returned in the 8314 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8315 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8316 ** 8317 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8318 ** <dd>This parameter records the number of separate memory allocations 8319 ** currently checked out.</dd>)^ 8320 ** 8321 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8322 ** <dd>This parameter returns the number of pages used out of the 8323 ** [pagecache memory allocator] that was configured using 8324 ** [SQLITE_CONFIG_PAGECACHE]. The 8325 ** value returned is in pages, not in bytes.</dd>)^ 8326 ** 8327 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8328 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8329 ** <dd>This parameter returns the number of bytes of page cache 8330 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8331 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8332 ** returned value includes allocations that overflowed because they 8333 ** where too large (they were larger than the "sz" parameter to 8334 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8335 ** no space was left in the page cache.</dd>)^ 8336 ** 8337 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8338 ** <dd>This parameter records the largest memory allocation request 8339 ** handed to the [pagecache memory allocator]. Only the value returned in the 8340 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8341 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8342 ** 8343 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8344 ** <dd>No longer used.</dd> 8345 ** 8346 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8347 ** <dd>No longer used.</dd> 8348 ** 8349 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8350 ** <dd>No longer used.</dd> 8351 ** 8352 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8353 ** <dd>The *pHighwater parameter records the deepest parser stack. 8354 ** The *pCurrent value is undefined. The *pHighwater value is only 8355 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8356 ** </dl> 8357 ** 8358 ** New status parameters may be added from time to time. 8359 */ 8360 #define SQLITE_STATUS_MEMORY_USED 0 8361 #define SQLITE_STATUS_PAGECACHE_USED 1 8362 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8363 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8364 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8365 #define SQLITE_STATUS_MALLOC_SIZE 5 8366 #define SQLITE_STATUS_PARSER_STACK 6 8367 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8368 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8369 #define SQLITE_STATUS_MALLOC_COUNT 9 8370 8371 /* 8372 ** CAPI3REF: Database Connection Status 8373 ** METHOD: sqlite3 8374 ** 8375 ** ^This interface is used to retrieve runtime status information 8376 ** about a single [database connection]. ^The first argument is the 8377 ** database connection object to be interrogated. ^The second argument 8378 ** is an integer constant, taken from the set of 8379 ** [SQLITE_DBSTATUS options], that 8380 ** determines the parameter to interrogate. The set of 8381 ** [SQLITE_DBSTATUS options] is likely 8382 ** to grow in future releases of SQLite. 8383 ** 8384 ** ^The current value of the requested parameter is written into *pCur 8385 ** and the highest instantaneous value is written into *pHiwtr. ^If 8386 ** the resetFlg is true, then the highest instantaneous value is 8387 ** reset back down to the current value. 8388 ** 8389 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8390 ** non-zero [error code] on failure. 8391 ** 8392 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8393 */ 8394 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8395 8396 /* 8397 ** CAPI3REF: Status Parameters for database connections 8398 ** KEYWORDS: {SQLITE_DBSTATUS options} 8399 ** 8400 ** These constants are the available integer "verbs" that can be passed as 8401 ** the second argument to the [sqlite3_db_status()] interface. 8402 ** 8403 ** New verbs may be added in future releases of SQLite. Existing verbs 8404 ** might be discontinued. Applications should check the return code from 8405 ** [sqlite3_db_status()] to make sure that the call worked. 8406 ** The [sqlite3_db_status()] interface will return a non-zero error code 8407 ** if a discontinued or unsupported verb is invoked. 8408 ** 8409 ** <dl> 8410 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8411 ** <dd>This parameter returns the number of lookaside memory slots currently 8412 ** checked out.</dd>)^ 8413 ** 8414 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8415 ** <dd>This parameter returns the number of malloc attempts that were 8416 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8417 ** the current value is always zero.)^ 8418 ** 8419 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8420 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8421 ** <dd>This parameter returns the number malloc attempts that might have 8422 ** been satisfied using lookaside memory but failed due to the amount of 8423 ** memory requested being larger than the lookaside slot size. 8424 ** Only the high-water value is meaningful; 8425 ** the current value is always zero.)^ 8426 ** 8427 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8428 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8429 ** <dd>This parameter returns the number malloc attempts that might have 8430 ** been satisfied using lookaside memory but failed due to all lookaside 8431 ** memory already being in use. 8432 ** Only the high-water value is meaningful; 8433 ** the current value is always zero.)^ 8434 ** 8435 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8436 ** <dd>This parameter returns the approximate number of bytes of heap 8437 ** memory used by all pager caches associated with the database connection.)^ 8438 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8439 ** 8440 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8441 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8442 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8443 ** pager cache is shared between two or more connections the bytes of heap 8444 ** memory used by that pager cache is divided evenly between the attached 8445 ** connections.)^ In other words, if none of the pager caches associated 8446 ** with the database connection are shared, this request returns the same 8447 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8448 ** shared, the value returned by this call will be smaller than that returned 8449 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8450 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8451 ** 8452 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8453 ** <dd>This parameter returns the approximate number of bytes of heap 8454 ** memory used to store the schema for all databases associated 8455 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8456 ** ^The full amount of memory used by the schemas is reported, even if the 8457 ** schema memory is shared with other database connections due to 8458 ** [shared cache mode] being enabled. 8459 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8460 ** 8461 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8462 ** <dd>This parameter returns the approximate number of bytes of heap 8463 ** and lookaside memory used by all prepared statements associated with 8464 ** the database connection.)^ 8465 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8466 ** </dd> 8467 ** 8468 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8469 ** <dd>This parameter returns the number of pager cache hits that have 8470 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8471 ** is always 0. 8472 ** </dd> 8473 ** 8474 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8475 ** <dd>This parameter returns the number of pager cache misses that have 8476 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8477 ** is always 0. 8478 ** </dd> 8479 ** 8480 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8481 ** <dd>This parameter returns the number of dirty cache entries that have 8482 ** been written to disk. Specifically, the number of pages written to the 8483 ** wal file in wal mode databases, or the number of pages written to the 8484 ** database file in rollback mode databases. Any pages written as part of 8485 ** transaction rollback or database recovery operations are not included. 8486 ** If an IO or other error occurs while writing a page to disk, the effect 8487 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8488 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8489 ** </dd> 8490 ** 8491 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8492 ** <dd>This parameter returns the number of dirty cache entries that have 8493 ** been written to disk in the middle of a transaction due to the page 8494 ** cache overflowing. Transactions are more efficient if they are written 8495 ** to disk all at once. When pages spill mid-transaction, that introduces 8496 ** additional overhead. This parameter can be used help identify 8497 ** inefficiencies that can be resolved by increasing the cache size. 8498 ** </dd> 8499 ** 8500 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8501 ** <dd>This parameter returns zero for the current value if and only if 8502 ** all foreign key constraints (deferred or immediate) have been 8503 ** resolved.)^ ^The highwater mark is always 0. 8504 ** </dd> 8505 ** </dl> 8506 */ 8507 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8508 #define SQLITE_DBSTATUS_CACHE_USED 1 8509 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8510 #define SQLITE_DBSTATUS_STMT_USED 3 8511 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8512 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8513 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8514 #define SQLITE_DBSTATUS_CACHE_HIT 7 8515 #define SQLITE_DBSTATUS_CACHE_MISS 8 8516 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8517 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8518 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8519 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8520 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8521 8522 8523 /* 8524 ** CAPI3REF: Prepared Statement Status 8525 ** METHOD: sqlite3_stmt 8526 ** 8527 ** ^(Each prepared statement maintains various 8528 ** [SQLITE_STMTSTATUS counters] that measure the number 8529 ** of times it has performed specific operations.)^ These counters can 8530 ** be used to monitor the performance characteristics of the prepared 8531 ** statements. For example, if the number of table steps greatly exceeds 8532 ** the number of table searches or result rows, that would tend to indicate 8533 ** that the prepared statement is using a full table scan rather than 8534 ** an index. 8535 ** 8536 ** ^(This interface is used to retrieve and reset counter values from 8537 ** a [prepared statement]. The first argument is the prepared statement 8538 ** object to be interrogated. The second argument 8539 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8540 ** to be interrogated.)^ 8541 ** ^The current value of the requested counter is returned. 8542 ** ^If the resetFlg is true, then the counter is reset to zero after this 8543 ** interface call returns. 8544 ** 8545 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8546 */ 8547 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8548 8549 /* 8550 ** CAPI3REF: Status Parameters for prepared statements 8551 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8552 ** 8553 ** These preprocessor macros define integer codes that name counter 8554 ** values associated with the [sqlite3_stmt_status()] interface. 8555 ** The meanings of the various counters are as follows: 8556 ** 8557 ** <dl> 8558 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8559 ** <dd>^This is the number of times that SQLite has stepped forward in 8560 ** a table as part of a full table scan. Large numbers for this counter 8561 ** may indicate opportunities for performance improvement through 8562 ** careful use of indices.</dd> 8563 ** 8564 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8565 ** <dd>^This is the number of sort operations that have occurred. 8566 ** A non-zero value in this counter may indicate an opportunity to 8567 ** improvement performance through careful use of indices.</dd> 8568 ** 8569 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8570 ** <dd>^This is the number of rows inserted into transient indices that 8571 ** were created automatically in order to help joins run faster. 8572 ** A non-zero value in this counter may indicate an opportunity to 8573 ** improvement performance by adding permanent indices that do not 8574 ** need to be reinitialized each time the statement is run.</dd> 8575 ** 8576 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8577 ** <dd>^This is the number of virtual machine operations executed 8578 ** by the prepared statement if that number is less than or equal 8579 ** to 2147483647. The number of virtual machine operations can be 8580 ** used as a proxy for the total work done by the prepared statement. 8581 ** If the number of virtual machine operations exceeds 2147483647 8582 ** then the value returned by this statement status code is undefined. 8583 ** 8584 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8585 ** <dd>^This is the number of times that the prepare statement has been 8586 ** automatically regenerated due to schema changes or changes to 8587 ** [bound parameters] that might affect the query plan. 8588 ** 8589 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8590 ** <dd>^This is the number of times that the prepared statement has 8591 ** been run. A single "run" for the purposes of this counter is one 8592 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8593 ** The counter is incremented on the first [sqlite3_step()] call of each 8594 ** cycle. 8595 ** 8596 ** [[SQLITE_STMTSTATUS_FILTER_MISS]] 8597 ** [[SQLITE_STMTSTATUS_FILTER HIT]] 8598 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 8599 ** SQLITE_STMTSTATUS_FILTER_MISS</dt> 8600 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 8601 ** step was bypassed because a Bloom filter returned not-found. The 8602 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 8603 ** times that the Bloom filter returned a find, and thus the join step 8604 ** had to be processed as normal. 8605 ** 8606 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8607 ** <dd>^This is the approximate number of bytes of heap memory 8608 ** used to store the prepared statement. ^This value is not actually 8609 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8610 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8611 ** </dd> 8612 ** </dl> 8613 */ 8614 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8615 #define SQLITE_STMTSTATUS_SORT 2 8616 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8617 #define SQLITE_STMTSTATUS_VM_STEP 4 8618 #define SQLITE_STMTSTATUS_REPREPARE 5 8619 #define SQLITE_STMTSTATUS_RUN 6 8620 #define SQLITE_STMTSTATUS_FILTER_MISS 7 8621 #define SQLITE_STMTSTATUS_FILTER_HIT 8 8622 #define SQLITE_STMTSTATUS_MEMUSED 99 8623 8624 /* 8625 ** CAPI3REF: Custom Page Cache Object 8626 ** 8627 ** The sqlite3_pcache type is opaque. It is implemented by 8628 ** the pluggable module. The SQLite core has no knowledge of 8629 ** its size or internal structure and never deals with the 8630 ** sqlite3_pcache object except by holding and passing pointers 8631 ** to the object. 8632 ** 8633 ** See [sqlite3_pcache_methods2] for additional information. 8634 */ 8635 typedef struct sqlite3_pcache sqlite3_pcache; 8636 8637 /* 8638 ** CAPI3REF: Custom Page Cache Object 8639 ** 8640 ** The sqlite3_pcache_page object represents a single page in the 8641 ** page cache. The page cache will allocate instances of this 8642 ** object. Various methods of the page cache use pointers to instances 8643 ** of this object as parameters or as their return value. 8644 ** 8645 ** See [sqlite3_pcache_methods2] for additional information. 8646 */ 8647 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8648 struct sqlite3_pcache_page { 8649 void *pBuf; /* The content of the page */ 8650 void *pExtra; /* Extra information associated with the page */ 8651 }; 8652 8653 /* 8654 ** CAPI3REF: Application Defined Page Cache. 8655 ** KEYWORDS: {page cache} 8656 ** 8657 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8658 ** register an alternative page cache implementation by passing in an 8659 ** instance of the sqlite3_pcache_methods2 structure.)^ 8660 ** In many applications, most of the heap memory allocated by 8661 ** SQLite is used for the page cache. 8662 ** By implementing a 8663 ** custom page cache using this API, an application can better control 8664 ** the amount of memory consumed by SQLite, the way in which 8665 ** that memory is allocated and released, and the policies used to 8666 ** determine exactly which parts of a database file are cached and for 8667 ** how long. 8668 ** 8669 ** The alternative page cache mechanism is an 8670 ** extreme measure that is only needed by the most demanding applications. 8671 ** The built-in page cache is recommended for most uses. 8672 ** 8673 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8674 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8675 ** the application may discard the parameter after the call to 8676 ** [sqlite3_config()] returns.)^ 8677 ** 8678 ** [[the xInit() page cache method]] 8679 ** ^(The xInit() method is called once for each effective 8680 ** call to [sqlite3_initialize()])^ 8681 ** (usually only once during the lifetime of the process). ^(The xInit() 8682 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8683 ** The intent of the xInit() method is to set up global data structures 8684 ** required by the custom page cache implementation. 8685 ** ^(If the xInit() method is NULL, then the 8686 ** built-in default page cache is used instead of the application defined 8687 ** page cache.)^ 8688 ** 8689 ** [[the xShutdown() page cache method]] 8690 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8691 ** It can be used to clean up 8692 ** any outstanding resources before process shutdown, if required. 8693 ** ^The xShutdown() method may be NULL. 8694 ** 8695 ** ^SQLite automatically serializes calls to the xInit method, 8696 ** so the xInit method need not be threadsafe. ^The 8697 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8698 ** not need to be threadsafe either. All other methods must be threadsafe 8699 ** in multithreaded applications. 8700 ** 8701 ** ^SQLite will never invoke xInit() more than once without an intervening 8702 ** call to xShutdown(). 8703 ** 8704 ** [[the xCreate() page cache methods]] 8705 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8706 ** SQLite will typically create one cache instance for each open database file, 8707 ** though this is not guaranteed. ^The 8708 ** first parameter, szPage, is the size in bytes of the pages that must 8709 ** be allocated by the cache. ^szPage will always a power of two. ^The 8710 ** second parameter szExtra is a number of bytes of extra storage 8711 ** associated with each page cache entry. ^The szExtra parameter will 8712 ** a number less than 250. SQLite will use the 8713 ** extra szExtra bytes on each page to store metadata about the underlying 8714 ** database page on disk. The value passed into szExtra depends 8715 ** on the SQLite version, the target platform, and how SQLite was compiled. 8716 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8717 ** created will be used to cache database pages of a file stored on disk, or 8718 ** false if it is used for an in-memory database. The cache implementation 8719 ** does not have to do anything special based with the value of bPurgeable; 8720 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8721 ** never invoke xUnpin() except to deliberately delete a page. 8722 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8723 ** false will always have the "discard" flag set to true. 8724 ** ^Hence, a cache created with bPurgeable false will 8725 ** never contain any unpinned pages. 8726 ** 8727 ** [[the xCachesize() page cache method]] 8728 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8729 ** suggested maximum cache-size (number of pages stored by) the cache 8730 ** instance passed as the first argument. This is the value configured using 8731 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8732 ** parameter, the implementation is not required to do anything with this 8733 ** value; it is advisory only. 8734 ** 8735 ** [[the xPagecount() page cache methods]] 8736 ** The xPagecount() method must return the number of pages currently 8737 ** stored in the cache, both pinned and unpinned. 8738 ** 8739 ** [[the xFetch() page cache methods]] 8740 ** The xFetch() method locates a page in the cache and returns a pointer to 8741 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8742 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8743 ** pointer to a buffer of szPage bytes used to store the content of a 8744 ** single database page. The pExtra element of sqlite3_pcache_page will be 8745 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8746 ** for each entry in the page cache. 8747 ** 8748 ** The page to be fetched is determined by the key. ^The minimum key value 8749 ** is 1. After it has been retrieved using xFetch, the page is considered 8750 ** to be "pinned". 8751 ** 8752 ** If the requested page is already in the page cache, then the page cache 8753 ** implementation must return a pointer to the page buffer with its content 8754 ** intact. If the requested page is not already in the cache, then the 8755 ** cache implementation should use the value of the createFlag 8756 ** parameter to help it determined what action to take: 8757 ** 8758 ** <table border=1 width=85% align=center> 8759 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8760 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8761 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8762 ** Otherwise return NULL. 8763 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8764 ** NULL if allocating a new page is effectively impossible. 8765 ** </table> 8766 ** 8767 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8768 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8769 ** failed.)^ In between the xFetch() calls, SQLite may 8770 ** attempt to unpin one or more cache pages by spilling the content of 8771 ** pinned pages to disk and synching the operating system disk cache. 8772 ** 8773 ** [[the xUnpin() page cache method]] 8774 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8775 ** as its second argument. If the third parameter, discard, is non-zero, 8776 ** then the page must be evicted from the cache. 8777 ** ^If the discard parameter is 8778 ** zero, then the page may be discarded or retained at the discretion of 8779 ** page cache implementation. ^The page cache implementation 8780 ** may choose to evict unpinned pages at any time. 8781 ** 8782 ** The cache must not perform any reference counting. A single 8783 ** call to xUnpin() unpins the page regardless of the number of prior calls 8784 ** to xFetch(). 8785 ** 8786 ** [[the xRekey() page cache methods]] 8787 ** The xRekey() method is used to change the key value associated with the 8788 ** page passed as the second argument. If the cache 8789 ** previously contains an entry associated with newKey, it must be 8790 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8791 ** to be pinned. 8792 ** 8793 ** When SQLite calls the xTruncate() method, the cache must discard all 8794 ** existing cache entries with page numbers (keys) greater than or equal 8795 ** to the value of the iLimit parameter passed to xTruncate(). If any 8796 ** of these pages are pinned, they are implicitly unpinned, meaning that 8797 ** they can be safely discarded. 8798 ** 8799 ** [[the xDestroy() page cache method]] 8800 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8801 ** All resources associated with the specified cache should be freed. ^After 8802 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8803 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8804 ** functions. 8805 ** 8806 ** [[the xShrink() page cache method]] 8807 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8808 ** free up as much of heap memory as possible. The page cache implementation 8809 ** is not obligated to free any memory, but well-behaved implementations should 8810 ** do their best. 8811 */ 8812 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8813 struct sqlite3_pcache_methods2 { 8814 int iVersion; 8815 void *pArg; 8816 int (*xInit)(void*); 8817 void (*xShutdown)(void*); 8818 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8819 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8820 int (*xPagecount)(sqlite3_pcache*); 8821 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8822 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8823 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8824 unsigned oldKey, unsigned newKey); 8825 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8826 void (*xDestroy)(sqlite3_pcache*); 8827 void (*xShrink)(sqlite3_pcache*); 8828 }; 8829 8830 /* 8831 ** This is the obsolete pcache_methods object that has now been replaced 8832 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8833 ** retained in the header file for backwards compatibility only. 8834 */ 8835 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8836 struct sqlite3_pcache_methods { 8837 void *pArg; 8838 int (*xInit)(void*); 8839 void (*xShutdown)(void*); 8840 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8841 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8842 int (*xPagecount)(sqlite3_pcache*); 8843 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8844 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8845 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8846 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8847 void (*xDestroy)(sqlite3_pcache*); 8848 }; 8849 8850 8851 /* 8852 ** CAPI3REF: Online Backup Object 8853 ** 8854 ** The sqlite3_backup object records state information about an ongoing 8855 ** online backup operation. ^The sqlite3_backup object is created by 8856 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8857 ** [sqlite3_backup_finish()]. 8858 ** 8859 ** See Also: [Using the SQLite Online Backup API] 8860 */ 8861 typedef struct sqlite3_backup sqlite3_backup; 8862 8863 /* 8864 ** CAPI3REF: Online Backup API. 8865 ** 8866 ** The backup API copies the content of one database into another. 8867 ** It is useful either for creating backups of databases or 8868 ** for copying in-memory databases to or from persistent files. 8869 ** 8870 ** See Also: [Using the SQLite Online Backup API] 8871 ** 8872 ** ^SQLite holds a write transaction open on the destination database file 8873 ** for the duration of the backup operation. 8874 ** ^The source database is read-locked only while it is being read; 8875 ** it is not locked continuously for the entire backup operation. 8876 ** ^Thus, the backup may be performed on a live source database without 8877 ** preventing other database connections from 8878 ** reading or writing to the source database while the backup is underway. 8879 ** 8880 ** ^(To perform a backup operation: 8881 ** <ol> 8882 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8883 ** backup, 8884 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8885 ** the data between the two databases, and finally 8886 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8887 ** associated with the backup operation. 8888 ** </ol>)^ 8889 ** There should be exactly one call to sqlite3_backup_finish() for each 8890 ** successful call to sqlite3_backup_init(). 8891 ** 8892 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8893 ** 8894 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8895 ** [database connection] associated with the destination database 8896 ** and the database name, respectively. 8897 ** ^The database name is "main" for the main database, "temp" for the 8898 ** temporary database, or the name specified after the AS keyword in 8899 ** an [ATTACH] statement for an attached database. 8900 ** ^The S and M arguments passed to 8901 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8902 ** and database name of the source database, respectively. 8903 ** ^The source and destination [database connections] (parameters S and D) 8904 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8905 ** an error. 8906 ** 8907 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8908 ** there is already a read or read-write transaction open on the 8909 ** destination database. 8910 ** 8911 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8912 ** returned and an error code and error message are stored in the 8913 ** destination [database connection] D. 8914 ** ^The error code and message for the failed call to sqlite3_backup_init() 8915 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8916 ** [sqlite3_errmsg16()] functions. 8917 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8918 ** [sqlite3_backup] object. 8919 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8920 ** sqlite3_backup_finish() functions to perform the specified backup 8921 ** operation. 8922 ** 8923 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8924 ** 8925 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8926 ** the source and destination databases specified by [sqlite3_backup] object B. 8927 ** ^If N is negative, all remaining source pages are copied. 8928 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8929 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8930 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8931 ** from source to destination, then it returns [SQLITE_DONE]. 8932 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8933 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8934 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8935 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8936 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8937 ** 8938 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8939 ** <ol> 8940 ** <li> the destination database was opened read-only, or 8941 ** <li> the destination database is using write-ahead-log journaling 8942 ** and the destination and source page sizes differ, or 8943 ** <li> the destination database is an in-memory database and the 8944 ** destination and source page sizes differ. 8945 ** </ol>)^ 8946 ** 8947 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8948 ** the [sqlite3_busy_handler | busy-handler function] 8949 ** is invoked (if one is specified). ^If the 8950 ** busy-handler returns non-zero before the lock is available, then 8951 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8952 ** sqlite3_backup_step() can be retried later. ^If the source 8953 ** [database connection] 8954 ** is being used to write to the source database when sqlite3_backup_step() 8955 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8956 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8957 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8958 ** [SQLITE_READONLY] is returned, then 8959 ** there is no point in retrying the call to sqlite3_backup_step(). These 8960 ** errors are considered fatal.)^ The application must accept 8961 ** that the backup operation has failed and pass the backup operation handle 8962 ** to the sqlite3_backup_finish() to release associated resources. 8963 ** 8964 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8965 ** on the destination file. ^The exclusive lock is not released until either 8966 ** sqlite3_backup_finish() is called or the backup operation is complete 8967 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8968 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8969 ** lasts for the duration of the sqlite3_backup_step() call. 8970 ** ^Because the source database is not locked between calls to 8971 ** sqlite3_backup_step(), the source database may be modified mid-way 8972 ** through the backup process. ^If the source database is modified by an 8973 ** external process or via a database connection other than the one being 8974 ** used by the backup operation, then the backup will be automatically 8975 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8976 ** database is modified by the using the same database connection as is used 8977 ** by the backup operation, then the backup database is automatically 8978 ** updated at the same time. 8979 ** 8980 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8981 ** 8982 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8983 ** application wishes to abandon the backup operation, the application 8984 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8985 ** ^The sqlite3_backup_finish() interfaces releases all 8986 ** resources associated with the [sqlite3_backup] object. 8987 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8988 ** active write-transaction on the destination database is rolled back. 8989 ** The [sqlite3_backup] object is invalid 8990 ** and may not be used following a call to sqlite3_backup_finish(). 8991 ** 8992 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8993 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8994 ** sqlite3_backup_step() completed. 8995 ** ^If an out-of-memory condition or IO error occurred during any prior 8996 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8997 ** sqlite3_backup_finish() returns the corresponding [error code]. 8998 ** 8999 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 9000 ** is not a permanent error and does not affect the return value of 9001 ** sqlite3_backup_finish(). 9002 ** 9003 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 9004 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 9005 ** 9006 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 9007 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 9008 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 9009 ** in the source database at the conclusion of the most recent 9010 ** sqlite3_backup_step(). 9011 ** ^(The values returned by these functions are only updated by 9012 ** sqlite3_backup_step(). If the source database is modified in a way that 9013 ** changes the size of the source database or the number of pages remaining, 9014 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 9015 ** and sqlite3_backup_remaining() until after the next 9016 ** sqlite3_backup_step().)^ 9017 ** 9018 ** <b>Concurrent Usage of Database Handles</b> 9019 ** 9020 ** ^The source [database connection] may be used by the application for other 9021 ** purposes while a backup operation is underway or being initialized. 9022 ** ^If SQLite is compiled and configured to support threadsafe database 9023 ** connections, then the source database connection may be used concurrently 9024 ** from within other threads. 9025 ** 9026 ** However, the application must guarantee that the destination 9027 ** [database connection] is not passed to any other API (by any thread) after 9028 ** sqlite3_backup_init() is called and before the corresponding call to 9029 ** sqlite3_backup_finish(). SQLite does not currently check to see 9030 ** if the application incorrectly accesses the destination [database connection] 9031 ** and so no error code is reported, but the operations may malfunction 9032 ** nevertheless. Use of the destination database connection while a 9033 ** backup is in progress might also cause a mutex deadlock. 9034 ** 9035 ** If running in [shared cache mode], the application must 9036 ** guarantee that the shared cache used by the destination database 9037 ** is not accessed while the backup is running. In practice this means 9038 ** that the application must guarantee that the disk file being 9039 ** backed up to is not accessed by any connection within the process, 9040 ** not just the specific connection that was passed to sqlite3_backup_init(). 9041 ** 9042 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 9043 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 9044 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 9045 ** APIs are not strictly speaking threadsafe. If they are invoked at the 9046 ** same time as another thread is invoking sqlite3_backup_step() it is 9047 ** possible that they return invalid values. 9048 */ 9049 SQLITE_API sqlite3_backup *sqlite3_backup_init( 9050 sqlite3 *pDest, /* Destination database handle */ 9051 const char *zDestName, /* Destination database name */ 9052 sqlite3 *pSource, /* Source database handle */ 9053 const char *zSourceName /* Source database name */ 9054 ); 9055 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9056 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9057 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9058 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9059 9060 /* 9061 ** CAPI3REF: Unlock Notification 9062 ** METHOD: sqlite3 9063 ** 9064 ** ^When running in shared-cache mode, a database operation may fail with 9065 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9066 ** individual tables within the shared-cache cannot be obtained. See 9067 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9068 ** ^This API may be used to register a callback that SQLite will invoke 9069 ** when the connection currently holding the required lock relinquishes it. 9070 ** ^This API is only available if the library was compiled with the 9071 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9072 ** 9073 ** See Also: [Using the SQLite Unlock Notification Feature]. 9074 ** 9075 ** ^Shared-cache locks are released when a database connection concludes 9076 ** its current transaction, either by committing it or rolling it back. 9077 ** 9078 ** ^When a connection (known as the blocked connection) fails to obtain a 9079 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9080 ** identity of the database connection (the blocking connection) that 9081 ** has locked the required resource is stored internally. ^After an 9082 ** application receives an SQLITE_LOCKED error, it may call the 9083 ** sqlite3_unlock_notify() method with the blocked connection handle as 9084 ** the first argument to register for a callback that will be invoked 9085 ** when the blocking connections current transaction is concluded. ^The 9086 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9087 ** call that concludes the blocking connection's transaction. 9088 ** 9089 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9090 ** there is a chance that the blocking connection will have already 9091 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9092 ** If this happens, then the specified callback is invoked immediately, 9093 ** from within the call to sqlite3_unlock_notify().)^ 9094 ** 9095 ** ^If the blocked connection is attempting to obtain a write-lock on a 9096 ** shared-cache table, and more than one other connection currently holds 9097 ** a read-lock on the same table, then SQLite arbitrarily selects one of 9098 ** the other connections to use as the blocking connection. 9099 ** 9100 ** ^(There may be at most one unlock-notify callback registered by a 9101 ** blocked connection. If sqlite3_unlock_notify() is called when the 9102 ** blocked connection already has a registered unlock-notify callback, 9103 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9104 ** called with a NULL pointer as its second argument, then any existing 9105 ** unlock-notify callback is canceled. ^The blocked connections 9106 ** unlock-notify callback may also be canceled by closing the blocked 9107 ** connection using [sqlite3_close()]. 9108 ** 9109 ** The unlock-notify callback is not reentrant. If an application invokes 9110 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 9111 ** crash or deadlock may be the result. 9112 ** 9113 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9114 ** returns SQLITE_OK. 9115 ** 9116 ** <b>Callback Invocation Details</b> 9117 ** 9118 ** When an unlock-notify callback is registered, the application provides a 9119 ** single void* pointer that is passed to the callback when it is invoked. 9120 ** However, the signature of the callback function allows SQLite to pass 9121 ** it an array of void* context pointers. The first argument passed to 9122 ** an unlock-notify callback is a pointer to an array of void* pointers, 9123 ** and the second is the number of entries in the array. 9124 ** 9125 ** When a blocking connection's transaction is concluded, there may be 9126 ** more than one blocked connection that has registered for an unlock-notify 9127 ** callback. ^If two or more such blocked connections have specified the 9128 ** same callback function, then instead of invoking the callback function 9129 ** multiple times, it is invoked once with the set of void* context pointers 9130 ** specified by the blocked connections bundled together into an array. 9131 ** This gives the application an opportunity to prioritize any actions 9132 ** related to the set of unblocked database connections. 9133 ** 9134 ** <b>Deadlock Detection</b> 9135 ** 9136 ** Assuming that after registering for an unlock-notify callback a 9137 ** database waits for the callback to be issued before taking any further 9138 ** action (a reasonable assumption), then using this API may cause the 9139 ** application to deadlock. For example, if connection X is waiting for 9140 ** connection Y's transaction to be concluded, and similarly connection 9141 ** Y is waiting on connection X's transaction, then neither connection 9142 ** will proceed and the system may remain deadlocked indefinitely. 9143 ** 9144 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9145 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 9146 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9147 ** unlock-notify callback is registered. The system is said to be in 9148 ** a deadlocked state if connection A has registered for an unlock-notify 9149 ** callback on the conclusion of connection B's transaction, and connection 9150 ** B has itself registered for an unlock-notify callback when connection 9151 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 9152 ** the system is also considered to be deadlocked if connection B has 9153 ** registered for an unlock-notify callback on the conclusion of connection 9154 ** C's transaction, where connection C is waiting on connection A. ^Any 9155 ** number of levels of indirection are allowed. 9156 ** 9157 ** <b>The "DROP TABLE" Exception</b> 9158 ** 9159 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9160 ** always appropriate to call sqlite3_unlock_notify(). There is however, 9161 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9162 ** SQLite checks if there are any currently executing SELECT statements 9163 ** that belong to the same connection. If there are, SQLITE_LOCKED is 9164 ** returned. In this case there is no "blocking connection", so invoking 9165 ** sqlite3_unlock_notify() results in the unlock-notify callback being 9166 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 9167 ** or "DROP INDEX" query, an infinite loop might be the result. 9168 ** 9169 ** One way around this problem is to check the extended error code returned 9170 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9171 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9172 ** the special "DROP TABLE/INDEX" case, the extended error code is just 9173 ** SQLITE_LOCKED.)^ 9174 */ 9175 SQLITE_API int sqlite3_unlock_notify( 9176 sqlite3 *pBlocked, /* Waiting connection */ 9177 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9178 void *pNotifyArg /* Argument to pass to xNotify */ 9179 ); 9180 9181 9182 /* 9183 ** CAPI3REF: String Comparison 9184 ** 9185 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9186 ** and extensions to compare the contents of two buffers containing UTF-8 9187 ** strings in a case-independent fashion, using the same definition of "case 9188 ** independence" that SQLite uses internally when comparing identifiers. 9189 */ 9190 SQLITE_API int sqlite3_stricmp(const char *, const char *); 9191 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9192 9193 /* 9194 ** CAPI3REF: String Globbing 9195 * 9196 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9197 ** string X matches the [GLOB] pattern P. 9198 ** ^The definition of [GLOB] pattern matching used in 9199 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9200 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9201 ** is case sensitive. 9202 ** 9203 ** Note that this routine returns zero on a match and non-zero if the strings 9204 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9205 ** 9206 ** See also: [sqlite3_strlike()]. 9207 */ 9208 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9209 9210 /* 9211 ** CAPI3REF: String LIKE Matching 9212 * 9213 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9214 ** string X matches the [LIKE] pattern P with escape character E. 9215 ** ^The definition of [LIKE] pattern matching used in 9216 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9217 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9218 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9219 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9220 ** insensitive - equivalent upper and lower case ASCII characters match 9221 ** one another. 9222 ** 9223 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9224 ** only ASCII characters are case folded. 9225 ** 9226 ** Note that this routine returns zero on a match and non-zero if the strings 9227 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9228 ** 9229 ** See also: [sqlite3_strglob()]. 9230 */ 9231 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9232 9233 /* 9234 ** CAPI3REF: Error Logging Interface 9235 ** 9236 ** ^The [sqlite3_log()] interface writes a message into the [error log] 9237 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9238 ** ^If logging is enabled, the zFormat string and subsequent arguments are 9239 ** used with [sqlite3_snprintf()] to generate the final output string. 9240 ** 9241 ** The sqlite3_log() interface is intended for use by extensions such as 9242 ** virtual tables, collating functions, and SQL functions. While there is 9243 ** nothing to prevent an application from calling sqlite3_log(), doing so 9244 ** is considered bad form. 9245 ** 9246 ** The zFormat string must not be NULL. 9247 ** 9248 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9249 ** will not use dynamically allocated memory. The log message is stored in 9250 ** a fixed-length buffer on the stack. If the log message is longer than 9251 ** a few hundred characters, it will be truncated to the length of the 9252 ** buffer. 9253 */ 9254 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9255 9256 /* 9257 ** CAPI3REF: Write-Ahead Log Commit Hook 9258 ** METHOD: sqlite3 9259 ** 9260 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 9261 ** is invoked each time data is committed to a database in wal mode. 9262 ** 9263 ** ^(The callback is invoked by SQLite after the commit has taken place and 9264 ** the associated write-lock on the database released)^, so the implementation 9265 ** may read, write or [checkpoint] the database as required. 9266 ** 9267 ** ^The first parameter passed to the callback function when it is invoked 9268 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 9269 ** registering the callback. ^The second is a copy of the database handle. 9270 ** ^The third parameter is the name of the database that was written to - 9271 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9272 ** is the number of pages currently in the write-ahead log file, 9273 ** including those that were just committed. 9274 ** 9275 ** The callback function should normally return [SQLITE_OK]. ^If an error 9276 ** code is returned, that error will propagate back up through the 9277 ** SQLite code base to cause the statement that provoked the callback 9278 ** to report an error, though the commit will have still occurred. If the 9279 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9280 ** that does not correspond to any valid SQLite error code, the results 9281 ** are undefined. 9282 ** 9283 ** A single database handle may have at most a single write-ahead log callback 9284 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9285 ** previously registered write-ahead log callback. ^The return value is 9286 ** a copy of the third parameter from the previous call, if any, or 0. 9287 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9288 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9289 ** overwrite any prior [sqlite3_wal_hook()] settings. 9290 */ 9291 SQLITE_API void *sqlite3_wal_hook( 9292 sqlite3*, 9293 int(*)(void *,sqlite3*,const char*,int), 9294 void* 9295 ); 9296 9297 /* 9298 ** CAPI3REF: Configure an auto-checkpoint 9299 ** METHOD: sqlite3 9300 ** 9301 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9302 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9303 ** to automatically [checkpoint] 9304 ** after committing a transaction if there are N or 9305 ** more frames in the [write-ahead log] file. ^Passing zero or 9306 ** a negative value as the nFrame parameter disables automatic 9307 ** checkpoints entirely. 9308 ** 9309 ** ^The callback registered by this function replaces any existing callback 9310 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9311 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9312 ** configured by this function. 9313 ** 9314 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9315 ** from SQL. 9316 ** 9317 ** ^Checkpoints initiated by this mechanism are 9318 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9319 ** 9320 ** ^Every new [database connection] defaults to having the auto-checkpoint 9321 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9322 ** pages. The use of this interface 9323 ** is only necessary if the default setting is found to be suboptimal 9324 ** for a particular application. 9325 */ 9326 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9327 9328 /* 9329 ** CAPI3REF: Checkpoint a database 9330 ** METHOD: sqlite3 9331 ** 9332 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9333 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9334 ** 9335 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9336 ** [write-ahead log] for database X on [database connection] D to be 9337 ** transferred into the database file and for the write-ahead log to 9338 ** be reset. See the [checkpointing] documentation for addition 9339 ** information. 9340 ** 9341 ** This interface used to be the only way to cause a checkpoint to 9342 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9343 ** interface was added. This interface is retained for backwards 9344 ** compatibility and as a convenience for applications that need to manually 9345 ** start a callback but which do not need the full power (and corresponding 9346 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9347 */ 9348 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9349 9350 /* 9351 ** CAPI3REF: Checkpoint a database 9352 ** METHOD: sqlite3 9353 ** 9354 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9355 ** operation on database X of [database connection] D in mode M. Status 9356 ** information is written back into integers pointed to by L and C.)^ 9357 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9358 ** 9359 ** <dl> 9360 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9361 ** ^Checkpoint as many frames as possible without waiting for any database 9362 ** readers or writers to finish, then sync the database file if all frames 9363 ** in the log were checkpointed. ^The [busy-handler callback] 9364 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9365 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9366 ** if there are concurrent readers or writers. 9367 ** 9368 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9369 ** ^This mode blocks (it invokes the 9370 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9371 ** database writer and all readers are reading from the most recent database 9372 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9373 ** database file. ^This mode blocks new database writers while it is pending, 9374 ** but new database readers are allowed to continue unimpeded. 9375 ** 9376 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9377 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9378 ** that after checkpointing the log file it blocks (calls the 9379 ** [busy-handler callback]) 9380 ** until all readers are reading from the database file only. ^This ensures 9381 ** that the next writer will restart the log file from the beginning. 9382 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9383 ** database writer attempts while it is pending, but does not impede readers. 9384 ** 9385 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9386 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9387 ** addition that it also truncates the log file to zero bytes just prior 9388 ** to a successful return. 9389 ** </dl> 9390 ** 9391 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9392 ** the log file or to -1 if the checkpoint could not run because 9393 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9394 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9395 ** log file (including any that were already checkpointed before the function 9396 ** was called) or to -1 if the checkpoint could not run due to an error or 9397 ** because the database is not in WAL mode. ^Note that upon successful 9398 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9399 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9400 ** 9401 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9402 ** any other process is running a checkpoint operation at the same time, the 9403 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9404 ** busy-handler configured, it will not be invoked in this case. 9405 ** 9406 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9407 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9408 ** obtained immediately, and a busy-handler is configured, it is invoked and 9409 ** the writer lock retried until either the busy-handler returns 0 or the lock 9410 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9411 ** database readers as described above. ^If the busy-handler returns 0 before 9412 ** the writer lock is obtained or while waiting for database readers, the 9413 ** checkpoint operation proceeds from that point in the same way as 9414 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9415 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9416 ** 9417 ** ^If parameter zDb is NULL or points to a zero length string, then the 9418 ** specified operation is attempted on all WAL databases [attached] to 9419 ** [database connection] db. In this case the 9420 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9421 ** an SQLITE_BUSY error is encountered when processing one or more of the 9422 ** attached WAL databases, the operation is still attempted on any remaining 9423 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9424 ** error occurs while processing an attached database, processing is abandoned 9425 ** and the error code is returned to the caller immediately. ^If no error 9426 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9427 ** databases, SQLITE_OK is returned. 9428 ** 9429 ** ^If database zDb is the name of an attached database that is not in WAL 9430 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9431 ** zDb is not NULL (or a zero length string) and is not the name of any 9432 ** attached database, SQLITE_ERROR is returned to the caller. 9433 ** 9434 ** ^Unless it returns SQLITE_MISUSE, 9435 ** the sqlite3_wal_checkpoint_v2() interface 9436 ** sets the error information that is queried by 9437 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9438 ** 9439 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9440 ** from SQL. 9441 */ 9442 SQLITE_API int sqlite3_wal_checkpoint_v2( 9443 sqlite3 *db, /* Database handle */ 9444 const char *zDb, /* Name of attached database (or NULL) */ 9445 int eMode, /* SQLITE_CHECKPOINT_* value */ 9446 int *pnLog, /* OUT: Size of WAL log in frames */ 9447 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9448 ); 9449 9450 /* 9451 ** CAPI3REF: Checkpoint Mode Values 9452 ** KEYWORDS: {checkpoint mode} 9453 ** 9454 ** These constants define all valid values for the "checkpoint mode" passed 9455 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9456 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9457 ** meaning of each of these checkpoint modes. 9458 */ 9459 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9460 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9461 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ 9462 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9463 9464 /* 9465 ** CAPI3REF: Virtual Table Interface Configuration 9466 ** 9467 ** This function may be called by either the [xConnect] or [xCreate] method 9468 ** of a [virtual table] implementation to configure 9469 ** various facets of the virtual table interface. 9470 ** 9471 ** If this interface is invoked outside the context of an xConnect or 9472 ** xCreate virtual table method then the behavior is undefined. 9473 ** 9474 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9475 ** [database connection] in which the virtual table is being created and 9476 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9477 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9478 ** of the [virtual table configuration options]. The presence and meaning 9479 ** of parameters after C depend on which [virtual table configuration option] 9480 ** is used. 9481 */ 9482 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9483 9484 /* 9485 ** CAPI3REF: Virtual Table Configuration Options 9486 ** KEYWORDS: {virtual table configuration options} 9487 ** KEYWORDS: {virtual table configuration option} 9488 ** 9489 ** These macros define the various options to the 9490 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9491 ** can use to customize and optimize their behavior. 9492 ** 9493 ** <dl> 9494 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9495 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9496 ** <dd>Calls of the form 9497 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9498 ** where X is an integer. If X is zero, then the [virtual table] whose 9499 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9500 ** support constraints. In this configuration (which is the default) if 9501 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9502 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9503 ** specified as part of the users SQL statement, regardless of the actual 9504 ** ON CONFLICT mode specified. 9505 ** 9506 ** If X is non-zero, then the virtual table implementation guarantees 9507 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9508 ** any modifications to internal or persistent data structures have been made. 9509 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9510 ** is able to roll back a statement or database transaction, and abandon 9511 ** or continue processing the current SQL statement as appropriate. 9512 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9513 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9514 ** had been ABORT. 9515 ** 9516 ** Virtual table implementations that are required to handle OR REPLACE 9517 ** must do so within the [xUpdate] method. If a call to the 9518 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9519 ** CONFLICT policy is REPLACE, the virtual table implementation should 9520 ** silently replace the appropriate rows within the xUpdate callback and 9521 ** return SQLITE_OK. Or, if this is not possible, it may return 9522 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9523 ** constraint handling. 9524 ** </dd> 9525 ** 9526 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9527 ** <dd>Calls of the form 9528 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9529 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9530 ** prohibits that virtual table from being used from within triggers and 9531 ** views. 9532 ** </dd> 9533 ** 9534 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9535 ** <dd>Calls of the form 9536 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9537 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9538 ** identify that virtual table as being safe to use from within triggers 9539 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9540 ** virtual table can do no serious harm even if it is controlled by a 9541 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9542 ** flag unless absolutely necessary. 9543 ** </dd> 9544 ** </dl> 9545 */ 9546 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9547 #define SQLITE_VTAB_INNOCUOUS 2 9548 #define SQLITE_VTAB_DIRECTONLY 3 9549 9550 /* 9551 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9552 ** 9553 ** This function may only be called from within a call to the [xUpdate] method 9554 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9555 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9556 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9557 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9558 ** [virtual table]. 9559 */ 9560 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9561 9562 /* 9563 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9564 ** 9565 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9566 ** method of a [virtual table], then it might return true if the 9567 ** column is being fetched as part of an UPDATE operation during which the 9568 ** column value will not change. The virtual table implementation can use 9569 ** this hint as permission to substitute a return value that is less 9570 ** expensive to compute and that the corresponding 9571 ** [xUpdate] method understands as a "no-change" value. 9572 ** 9573 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9574 ** the column is not changed by the UPDATE statement, then the xColumn 9575 ** method can optionally return without setting a result, without calling 9576 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9577 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9578 ** same column in the [xUpdate] method. 9579 ** 9580 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9581 ** implementations should continue to give a correct answer even if the 9582 ** sqlite3_vtab_nochange() interface were to always return false. In the 9583 ** current implementation, the sqlite3_vtab_nochange() interface does always 9584 ** returns false for the enhanced [UPDATE FROM] statement. 9585 */ 9586 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9587 9588 /* 9589 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9590 ** METHOD: sqlite3_index_info 9591 ** 9592 ** This function may only be called from within a call to the [xBestIndex] 9593 ** method of a [virtual table]. This function returns a pointer to a string 9594 ** that is the name of the appropriate collation sequence to use for text 9595 ** comparisons on the constraint identified by its arguments. 9596 ** 9597 ** The first argument must be the pointer to the [sqlite3_index_info] object 9598 ** that is the first parameter to the xBestIndex() method. The second argument 9599 ** must be an index into the aConstraint[] array belonging to the 9600 ** sqlite3_index_info structure passed to xBestIndex. 9601 ** 9602 ** Important: 9603 ** The first parameter must be the same pointer that is passed into the 9604 ** xBestMethod() method. The first parameter may not be a pointer to a 9605 ** different [sqlite3_index_info] object, even an exact copy. 9606 ** 9607 ** The return value is computed as follows: 9608 ** 9609 ** <ol> 9610 ** <li><p> If the constraint comes from a WHERE clause expression that contains 9611 ** a [COLLATE operator], then the name of the collation specified by 9612 ** that COLLATE operator is returned. 9613 ** <li><p> If there is no COLLATE operator, but the column that is the subject 9614 ** of the constraint specifies an alternative collating sequence via 9615 ** a [COLLATE clause] on the column definition within the CREATE TABLE 9616 ** statement that was passed into [sqlite3_declare_vtab()], then the 9617 ** name of that alternative collating sequence is returned. 9618 ** <li><p> Otherwise, "BINARY" is returned. 9619 ** </ol> 9620 */ 9621 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9622 9623 /* 9624 ** CAPI3REF: Determine if a virtual table query is DISTINCT 9625 ** METHOD: sqlite3_index_info 9626 ** 9627 ** This API may only be used from within an [xBestIndex|xBestIndex method] 9628 ** of a [virtual table] implementation. The result of calling this 9629 ** interface from outside of xBestIndex() is undefined and probably harmful. 9630 ** 9631 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 9632 ** 3. The integer returned by sqlite3_vtab_distinct() 9633 ** gives the virtual table additional information about how the query 9634 ** planner wants the output to be ordered. As long as the virtual table 9635 ** can meet the ordering requirements of the query planner, it may set 9636 ** the "orderByConsumed" flag. 9637 ** 9638 ** <ol><li value="0"><p> 9639 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means 9640 ** that the query planner needs the virtual table to return all rows in the 9641 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 9642 ** [sqlite3_index_info] object. This is the default expectation. If the 9643 ** virtual table outputs all rows in sorted order, then it is always safe for 9644 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of 9645 ** the return value from sqlite3_vtab_distinct(). 9646 ** <li value="1"><p> 9647 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 9648 ** that the query planner does not need the rows to be returned in sorted order 9649 ** as long as all rows with the same values in all columns identified by the 9650 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 9651 ** is doing a GROUP BY. 9652 ** <li value="2"><p> 9653 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 9654 ** that the query planner does not need the rows returned in any particular 9655 ** order, as long as rows with the same values in all "aOrderBy" columns 9656 ** are adjacent.)^ ^(Furthermore, only a single row for each particular 9657 ** combination of values in the columns identified by the "aOrderBy" field 9658 ** needs to be returned.)^ ^It is always ok for two or more rows with the same 9659 ** values in all "aOrderBy" columns to be returned, as long as all such rows 9660 ** are adjacent. ^The virtual table may, if it chooses, omit extra rows 9661 ** that have the same value for all columns identified by "aOrderBy". 9662 ** ^However omitting the extra rows is optional. 9663 ** This mode is used for a DISTINCT query. 9664 ** <li value="3"><p> 9665 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means 9666 ** that the query planner needs only distinct rows but it does need the 9667 ** rows to be sorted.)^ ^The virtual table implementation is free to omit 9668 ** rows that are identical in all aOrderBy columns, if it wants to, but 9669 ** it is not required to omit any rows. This mode is used for queries 9670 ** that have both DISTINCT and ORDER BY clauses. 9671 ** </ol> 9672 ** 9673 ** ^For the purposes of comparing virtual table output values to see if the 9674 ** values are same value for sorting purposes, two NULL values are considered 9675 ** to be the same. In other words, the comparison operator is "IS" 9676 ** (or "IS NOT DISTINCT FROM") and not "==". 9677 ** 9678 ** If a virtual table implementation is unable to meet the requirements 9679 ** specified above, then it must not set the "orderByConsumed" flag in the 9680 ** [sqlite3_index_info] object or an incorrect answer may result. 9681 ** 9682 ** ^A virtual table implementation is always free to return rows in any order 9683 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the 9684 ** the "orderByConsumed" flag is unset, the query planner will add extra 9685 ** [bytecode] to ensure that the final results returned by the SQL query are 9686 ** ordered correctly. The use of the "orderByConsumed" flag and the 9687 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 9688 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 9689 ** flag might help queries against a virtual table to run faster. Being 9690 ** overly aggressive and setting the "orderByConsumed" flag when it is not 9691 ** valid to do so, on the other hand, might cause SQLite to return incorrect 9692 ** results. 9693 */ 9694 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 9695 9696 /* 9697 ** CAPI3REF: Identify and handle IN constraints in xBestIndex 9698 ** 9699 ** This interface may only be used from within an 9700 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 9701 ** The result of invoking this interface from any other context is 9702 ** undefined and probably harmful. 9703 ** 9704 ** ^(A constraint on a virtual table of the form 9705 ** "[IN operator|column IN (...)]" is 9706 ** communicated to the xBestIndex method as a 9707 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 9708 ** this constraint, it must set the corresponding 9709 ** aConstraintUsage[].argvIndex to a postive integer. ^(Then, under 9710 ** the usual mode of handling IN operators, SQLite generates [bytecode] 9711 ** that invokes the [xFilter|xFilter() method] once for each value 9712 ** on the right-hand side of the IN operator.)^ Thus the virtual table 9713 ** only sees a single value from the right-hand side of the IN operator 9714 ** at a time. 9715 ** 9716 ** In some cases, however, it would be advantageous for the virtual 9717 ** table to see all values on the right-hand of the IN operator all at 9718 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 9719 ** 9720 ** <ol> 9721 ** <li><p> 9722 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 9723 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 9724 ** is an [IN operator] that can be processed all at once. ^In other words, 9725 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism 9726 ** by which the virtual table can ask SQLite if all-at-once processing 9727 ** of the IN operator is even possible. 9728 ** 9729 ** <li><p> 9730 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 9731 ** to SQLite that the virtual table does or does not want to process 9732 ** the IN operator all-at-once, respectively. ^Thus when the third 9733 ** parameter (F) is non-negative, this interface is the mechanism by 9734 ** which the virtual table tells SQLite how it wants to process the 9735 ** IN operator. 9736 ** </ol> 9737 ** 9738 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 9739 ** within the same xBestIndex method call. ^For any given P,N pair, 9740 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same 9741 ** within the same xBestIndex call. ^If the interface returns true 9742 ** (non-zero), that means that the constraint is an IN operator 9743 ** that can be processed all-at-once. ^If the constraint is not an IN 9744 ** operator or cannot be processed all-at-once, then the interface returns 9745 ** false. 9746 ** 9747 ** ^(All-at-once processing of the IN operator is selected if both of the 9748 ** following conditions are met: 9749 ** 9750 ** <ol> 9751 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 9752 ** integer. This is how the virtual table tells SQLite that it wants to 9753 ** use the N-th constraint. 9754 ** 9755 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 9756 ** non-negative had F>=1. 9757 ** </ol>)^ 9758 ** 9759 ** ^If either or both of the conditions above are false, then SQLite uses 9760 ** the traditional one-at-a-time processing strategy for the IN constraint. 9761 ** ^If both conditions are true, then the argvIndex-th parameter to the 9762 ** xFilter method will be an [sqlite3_value] that appears to be NULL, 9763 ** but which can be passed to [sqlite3_vtab_in_first()] and 9764 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side 9765 ** of the IN constraint. 9766 */ 9767 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 9768 9769 /* 9770 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 9771 ** 9772 ** These interfaces are only useful from within the 9773 ** [xFilter|xFilter() method] of a [virtual table] implementation. 9774 ** The result of invoking these interfaces from any other context 9775 ** is undefined and probably harmful. 9776 ** 9777 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 9778 ** sqlite3_vtab_in_next(X,P) must be one of the parameters to the 9779 ** xFilter method which invokes these routines, and specifically 9780 ** a parameter that was previously selected for all-at-once IN constraint 9781 ** processing use the [sqlite3_vtab_in()] interface in the 9782 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 9783 ** an xFilter argument that was selected for all-at-once IN constraint 9784 ** processing, then these routines return [SQLITE_MISUSE])^ or perhaps 9785 ** exhibit some other undefined or harmful behavior. 9786 ** 9787 ** ^(Use these routines to access all values on the right-hand side 9788 ** of the IN constraint using code like the following: 9789 ** 9790 ** <blockquote><pre> 9791 ** for(rc=sqlite3_vtab_in_first(pList, &pVal); 9792 ** rc==SQLITE_OK && pVal 9793 ** rc=sqlite3_vtab_in_next(pList, &pVal) 9794 ** ){ 9795 ** // do something with pVal 9796 ** } 9797 ** if( rc!=SQLITE_OK ){ 9798 ** // an error has occurred 9799 ** } 9800 ** </pre></blockquote>)^ 9801 ** 9802 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 9803 ** routines return SQLITE_OK and set *P to point to the first or next value 9804 ** on the RHS of the IN constraint. ^If there are no more values on the 9805 ** right hand side of the IN constraint, then *P is set to NULL and these 9806 ** routines return [SQLITE_DONE]. ^The return value might be 9807 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 9808 ** 9809 ** The *ppOut values returned by these routines are only valid until the 9810 ** next call to either of these routines or until the end of the xFilter 9811 ** method from which these routines were called. If the virtual table 9812 ** implementation needs to retain the *ppOut values for longer, it must make 9813 ** copies. The *ppOut values are [protected sqlite3_value|protected]. 9814 */ 9815 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 9816 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 9817 9818 /* 9819 ** CAPI3REF: Constraint values in xBestIndex() 9820 ** METHOD: sqlite3_index_info 9821 ** 9822 ** This API may only be used from within the [xBestIndex|xBestIndex method] 9823 ** of a [virtual table] implementation. The result of calling this interface 9824 ** from outside of an xBestIndex method are undefined and probably harmful. 9825 ** 9826 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 9827 ** the [xBestIndex] method of a [virtual table] implementation, with P being 9828 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 9829 ** J being a 0-based index into P->aConstraint[], then this routine 9830 ** attempts to set *V to the value of the right-hand operand of 9831 ** that constraint if the right-hand operand is known. ^If the 9832 ** right-hand operand is not known, then *V is set to a NULL pointer. 9833 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 9834 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 9835 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 9836 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 9837 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 9838 ** something goes wrong. 9839 ** 9840 ** The sqlite3_vtab_rhs_value() interface is usually only successful if 9841 ** the right-hand operand of a constraint is a literal value in the original 9842 ** SQL statement. If the right-hand operand is an expression or a reference 9843 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 9844 ** will probably return [SQLITE_NOTFOUND]. 9845 ** 9846 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 9847 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 9848 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 9849 ** 9850 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 9851 ** and remains valid for the duration of the xBestIndex method call. 9852 ** ^When xBestIndex returns, the sqlite3_value object returned by 9853 ** sqlite3_vtab_rhs_value() is automatically deallocated. 9854 ** 9855 ** The "_rhs_" in the name of this routine is an abbreviation for 9856 ** "Right-Hand Side". 9857 */ 9858 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 9859 9860 /* 9861 ** CAPI3REF: Conflict resolution modes 9862 ** KEYWORDS: {conflict resolution mode} 9863 ** 9864 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 9865 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 9866 ** is for the SQL statement being evaluated. 9867 ** 9868 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 9869 ** return value from the [sqlite3_set_authorizer()] callback and that 9870 ** [SQLITE_ABORT] is also a [result code]. 9871 */ 9872 #define SQLITE_ROLLBACK 1 9873 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9874 #define SQLITE_FAIL 3 9875 /* #define SQLITE_ABORT 4 // Also an error code */ 9876 #define SQLITE_REPLACE 5 9877 9878 /* 9879 ** CAPI3REF: Prepared Statement Scan Status Opcodes 9880 ** KEYWORDS: {scanstatus options} 9881 ** 9882 ** The following constants can be used for the T parameter to the 9883 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9884 ** different metric for sqlite3_stmt_scanstatus() to return. 9885 ** 9886 ** When the value returned to V is a string, space to hold that string is 9887 ** managed by the prepared statement S and will be automatically freed when 9888 ** S is finalized. 9889 ** 9890 ** <dl> 9891 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9892 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9893 ** set to the total number of times that the X-th loop has run.</dd> 9894 ** 9895 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9896 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9897 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 9898 ** 9899 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9900 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 9901 ** query planner's estimate for the average number of rows output from each 9902 ** iteration of the X-th loop. If the query planner's estimates was accurate, 9903 ** then this value will approximate the quotient NVISIT/NLOOP and the 9904 ** product of this value for all prior loops with the same SELECTID will 9905 ** be the NLOOP value for the current loop. 9906 ** 9907 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9908 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9909 ** to a zero-terminated UTF-8 string containing the name of the index or table 9910 ** used for the X-th loop. 9911 ** 9912 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9913 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9914 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9915 ** description for the X-th loop. 9916 ** 9917 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9918 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 9919 ** "select-id" for the X-th loop. The select-id identifies which query or 9920 ** subquery the loop is part of. The main query has a select-id of zero. 9921 ** The select-id is the same value as is output in the first column 9922 ** of an [EXPLAIN QUERY PLAN] query. 9923 ** </dl> 9924 */ 9925 #define SQLITE_SCANSTAT_NLOOP 0 9926 #define SQLITE_SCANSTAT_NVISIT 1 9927 #define SQLITE_SCANSTAT_EST 2 9928 #define SQLITE_SCANSTAT_NAME 3 9929 #define SQLITE_SCANSTAT_EXPLAIN 4 9930 #define SQLITE_SCANSTAT_SELECTID 5 9931 9932 /* 9933 ** CAPI3REF: Prepared Statement Scan Status 9934 ** METHOD: sqlite3_stmt 9935 ** 9936 ** This interface returns information about the predicted and measured 9937 ** performance for pStmt. Advanced applications can use this 9938 ** interface to compare the predicted and the measured performance and 9939 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9940 ** 9941 ** Since this interface is expected to be rarely used, it is only 9942 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9943 ** compile-time option. 9944 ** 9945 ** The "iScanStatusOp" parameter determines which status information to return. 9946 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9947 ** of this interface is undefined. 9948 ** ^The requested measurement is written into a variable pointed to by 9949 ** the "pOut" parameter. 9950 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 9951 ** Loops are numbered starting from zero. ^If idx is out of range - less than 9952 ** zero or greater than or equal to the total number of loops used to implement 9953 ** the statement - a non-zero value is returned and the variable that pOut 9954 ** points to is unchanged. 9955 ** 9956 ** ^Statistics might not be available for all loops in all statements. ^In cases 9957 ** where there exist loops with no available statistics, this function behaves 9958 ** as if the loop did not exist - it returns non-zero and leave the variable 9959 ** that pOut points to unchanged. 9960 ** 9961 ** See also: [sqlite3_stmt_scanstatus_reset()] 9962 */ 9963 SQLITE_API int sqlite3_stmt_scanstatus( 9964 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9965 int idx, /* Index of loop to report on */ 9966 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9967 void *pOut /* Result written here */ 9968 ); 9969 9970 /* 9971 ** CAPI3REF: Zero Scan-Status Counters 9972 ** METHOD: sqlite3_stmt 9973 ** 9974 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9975 ** 9976 ** This API is only available if the library is built with pre-processor 9977 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9978 */ 9979 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9980 9981 /* 9982 ** CAPI3REF: Flush caches to disk mid-transaction 9983 ** METHOD: sqlite3 9984 ** 9985 ** ^If a write-transaction is open on [database connection] D when the 9986 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9987 ** pages in the pager-cache that are not currently in use are written out 9988 ** to disk. A dirty page may be in use if a database cursor created by an 9989 ** active SQL statement is reading from it, or if it is page 1 of a database 9990 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9991 ** interface flushes caches for all schemas - "main", "temp", and 9992 ** any [attached] databases. 9993 ** 9994 ** ^If this function needs to obtain extra database locks before dirty pages 9995 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 9996 ** immediately and there is a busy-handler callback configured, it is invoked 9997 ** in the usual manner. ^If the required lock still cannot be obtained, then 9998 ** the database is skipped and an attempt made to flush any dirty pages 9999 ** belonging to the next (if any) database. ^If any databases are skipped 10000 ** because locks cannot be obtained, but no other error occurs, this 10001 ** function returns SQLITE_BUSY. 10002 ** 10003 ** ^If any other error occurs while flushing dirty pages to disk (for 10004 ** example an IO error or out-of-memory condition), then processing is 10005 ** abandoned and an SQLite [error code] is returned to the caller immediately. 10006 ** 10007 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 10008 ** 10009 ** ^This function does not set the database handle error code or message 10010 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 10011 */ 10012 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 10013 10014 /* 10015 ** CAPI3REF: The pre-update hook. 10016 ** METHOD: sqlite3 10017 ** 10018 ** ^These interfaces are only available if SQLite is compiled using the 10019 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 10020 ** 10021 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 10022 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 10023 ** on a database table. 10024 ** ^At most one preupdate hook may be registered at a time on a single 10025 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 10026 ** the previous setting. 10027 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 10028 ** with a NULL pointer as the second parameter. 10029 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 10030 ** the first parameter to callbacks. 10031 ** 10032 ** ^The preupdate hook only fires for changes to real database tables; the 10033 ** preupdate hook is not invoked for changes to [virtual tables] or to 10034 ** system tables like sqlite_sequence or sqlite_stat1. 10035 ** 10036 ** ^The second parameter to the preupdate callback is a pointer to 10037 ** the [database connection] that registered the preupdate hook. 10038 ** ^The third parameter to the preupdate callback is one of the constants 10039 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 10040 ** kind of update operation that is about to occur. 10041 ** ^(The fourth parameter to the preupdate callback is the name of the 10042 ** database within the database connection that is being modified. This 10043 ** will be "main" for the main database or "temp" for TEMP tables or 10044 ** the name given after the AS keyword in the [ATTACH] statement for attached 10045 ** databases.)^ 10046 ** ^The fifth parameter to the preupdate callback is the name of the 10047 ** table that is being modified. 10048 ** 10049 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 10050 ** parameter passed to the preupdate callback is the initial [rowid] of the 10051 ** row being modified or deleted. For an INSERT operation on a rowid table, 10052 ** or any operation on a WITHOUT ROWID table, the value of the sixth 10053 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10054 ** seventh parameter is the final rowid value of the row being inserted 10055 ** or updated. The value of the seventh parameter passed to the callback 10056 ** function is not defined for operations on WITHOUT ROWID tables, or for 10057 ** DELETE operations on rowid tables. 10058 ** 10059 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10060 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10061 ** provide additional information about a preupdate event. These routines 10062 ** may only be called from within a preupdate callback. Invoking any of 10063 ** these routines from outside of a preupdate callback or with a 10064 ** [database connection] pointer that is different from the one supplied 10065 ** to the preupdate callback results in undefined and probably undesirable 10066 ** behavior. 10067 ** 10068 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10069 ** in the row that is being inserted, updated, or deleted. 10070 ** 10071 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10072 ** a [protected sqlite3_value] that contains the value of the Nth column of 10073 ** the table row before it is updated. The N parameter must be between 0 10074 ** and one less than the number of columns or the behavior will be 10075 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10076 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10077 ** behavior is undefined. The [sqlite3_value] that P points to 10078 ** will be destroyed when the preupdate callback returns. 10079 ** 10080 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10081 ** a [protected sqlite3_value] that contains the value of the Nth column of 10082 ** the table row after it is updated. The N parameter must be between 0 10083 ** and one less than the number of columns or the behavior will be 10084 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10085 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10086 ** behavior is undefined. The [sqlite3_value] that P points to 10087 ** will be destroyed when the preupdate callback returns. 10088 ** 10089 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10090 ** callback was invoked as a result of a direct insert, update, or delete 10091 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 10092 ** triggers; or 2 for changes resulting from triggers called by top-level 10093 ** triggers; and so forth. 10094 ** 10095 ** When the [sqlite3_blob_write()] API is used to update a blob column, 10096 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10097 ** in this case the new values are not available. In this case, when a 10098 ** callback made with op==SQLITE_DELETE is actuall a write using the 10099 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10100 ** the index of the column being written. In other cases, where the 10101 ** pre-update hook is being invoked for some other reason, including a 10102 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10103 ** 10104 ** See also: [sqlite3_update_hook()] 10105 */ 10106 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10107 SQLITE_API void *sqlite3_preupdate_hook( 10108 sqlite3 *db, 10109 void(*xPreUpdate)( 10110 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10111 sqlite3 *db, /* Database handle */ 10112 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10113 char const *zDb, /* Database name */ 10114 char const *zName, /* Table name */ 10115 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10116 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10117 ), 10118 void* 10119 ); 10120 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10121 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10122 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10123 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10124 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10125 #endif 10126 10127 /* 10128 ** CAPI3REF: Low-level system error code 10129 ** METHOD: sqlite3 10130 ** 10131 ** ^Attempt to return the underlying operating system error code or error 10132 ** number that caused the most recent I/O error or failure to open a file. 10133 ** The return value is OS-dependent. For example, on unix systems, after 10134 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10135 ** called to get back the underlying "errno" that caused the problem, such 10136 ** as ENOSPC, EAUTH, EISDIR, and so forth. 10137 */ 10138 SQLITE_API int sqlite3_system_errno(sqlite3*); 10139 10140 /* 10141 ** CAPI3REF: Database Snapshot 10142 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 10143 ** 10144 ** An instance of the snapshot object records the state of a [WAL mode] 10145 ** database for some specific point in history. 10146 ** 10147 ** In [WAL mode], multiple [database connections] that are open on the 10148 ** same database file can each be reading a different historical version 10149 ** of the database file. When a [database connection] begins a read 10150 ** transaction, that connection sees an unchanging copy of the database 10151 ** as it existed for the point in time when the transaction first started. 10152 ** Subsequent changes to the database from other connections are not seen 10153 ** by the reader until a new read transaction is started. 10154 ** 10155 ** The sqlite3_snapshot object records state information about an historical 10156 ** version of the database file so that it is possible to later open a new read 10157 ** transaction that sees that historical version of the database rather than 10158 ** the most recent version. 10159 */ 10160 typedef struct sqlite3_snapshot { 10161 unsigned char hidden[48]; 10162 } sqlite3_snapshot; 10163 10164 /* 10165 ** CAPI3REF: Record A Database Snapshot 10166 ** CONSTRUCTOR: sqlite3_snapshot 10167 ** 10168 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10169 ** new [sqlite3_snapshot] object that records the current state of 10170 ** schema S in database connection D. ^On success, the 10171 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10172 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10173 ** If there is not already a read-transaction open on schema S when 10174 ** this function is called, one is opened automatically. 10175 ** 10176 ** The following must be true for this function to succeed. If any of 10177 ** the following statements are false when sqlite3_snapshot_get() is 10178 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 10179 ** in this case. 10180 ** 10181 ** <ul> 10182 ** <li> The database handle must not be in [autocommit mode]. 10183 ** 10184 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 10185 ** 10186 ** <li> There must not be a write transaction open on schema S of database 10187 ** connection D. 10188 ** 10189 ** <li> One or more transactions must have been written to the current wal 10190 ** file since it was created on disk (by any connection). This means 10191 ** that a snapshot cannot be taken on a wal mode database with no wal 10192 ** file immediately after it is first opened. At least one transaction 10193 ** must be written to it first. 10194 ** </ul> 10195 ** 10196 ** This function may also return SQLITE_NOMEM. If it is called with the 10197 ** database handle in autocommit mode but fails for some other reason, 10198 ** whether or not a read transaction is opened on schema S is undefined. 10199 ** 10200 ** The [sqlite3_snapshot] object returned from a successful call to 10201 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10202 ** to avoid a memory leak. 10203 ** 10204 ** The [sqlite3_snapshot_get()] interface is only available when the 10205 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10206 */ 10207 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10208 sqlite3 *db, 10209 const char *zSchema, 10210 sqlite3_snapshot **ppSnapshot 10211 ); 10212 10213 /* 10214 ** CAPI3REF: Start a read transaction on an historical snapshot 10215 ** METHOD: sqlite3_snapshot 10216 ** 10217 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10218 ** transaction or upgrades an existing one for schema S of 10219 ** [database connection] D such that the read transaction refers to 10220 ** historical [snapshot] P, rather than the most recent change to the 10221 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10222 ** on success or an appropriate [error code] if it fails. 10223 ** 10224 ** ^In order to succeed, the database connection must not be in 10225 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10226 ** is already a read transaction open on schema S, then the database handle 10227 ** must have no active statements (SELECT statements that have been passed 10228 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10229 ** SQLITE_ERROR is returned if either of these conditions is violated, or 10230 ** if schema S does not exist, or if the snapshot object is invalid. 10231 ** 10232 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10233 ** snapshot has been overwritten by a [checkpoint]. In this case 10234 ** SQLITE_ERROR_SNAPSHOT is returned. 10235 ** 10236 ** If there is already a read transaction open when this function is 10237 ** invoked, then the same read transaction remains open (on the same 10238 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10239 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 10240 ** SQLITE_IOERR error code - is returned, then the final state of the 10241 ** read transaction is undefined. If SQLITE_OK is returned, then the 10242 ** read transaction is now open on database snapshot P. 10243 ** 10244 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10245 ** database connection D does not know that the database file for 10246 ** schema S is in [WAL mode]. A database connection might not know 10247 ** that the database file is in [WAL mode] if there has been no prior 10248 ** I/O on that database connection, or if the database entered [WAL mode] 10249 ** after the most recent I/O on the database connection.)^ 10250 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 10251 ** database connection in order to make it ready to use snapshots.) 10252 ** 10253 ** The [sqlite3_snapshot_open()] interface is only available when the 10254 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10255 */ 10256 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10257 sqlite3 *db, 10258 const char *zSchema, 10259 sqlite3_snapshot *pSnapshot 10260 ); 10261 10262 /* 10263 ** CAPI3REF: Destroy a snapshot 10264 ** DESTRUCTOR: sqlite3_snapshot 10265 ** 10266 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10267 ** The application must eventually free every [sqlite3_snapshot] object 10268 ** using this routine to avoid a memory leak. 10269 ** 10270 ** The [sqlite3_snapshot_free()] interface is only available when the 10271 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10272 */ 10273 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10274 10275 /* 10276 ** CAPI3REF: Compare the ages of two snapshot handles. 10277 ** METHOD: sqlite3_snapshot 10278 ** 10279 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10280 ** of two valid snapshot handles. 10281 ** 10282 ** If the two snapshot handles are not associated with the same database 10283 ** file, the result of the comparison is undefined. 10284 ** 10285 ** Additionally, the result of the comparison is only valid if both of the 10286 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10287 ** last time the wal file was deleted. The wal file is deleted when the 10288 ** database is changed back to rollback mode or when the number of database 10289 ** clients drops to zero. If either snapshot handle was obtained before the 10290 ** wal file was last deleted, the value returned by this function 10291 ** is undefined. 10292 ** 10293 ** Otherwise, this API returns a negative value if P1 refers to an older 10294 ** snapshot than P2, zero if the two handles refer to the same database 10295 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 10296 ** 10297 ** This interface is only available if SQLite is compiled with the 10298 ** [SQLITE_ENABLE_SNAPSHOT] option. 10299 */ 10300 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10301 sqlite3_snapshot *p1, 10302 sqlite3_snapshot *p2 10303 ); 10304 10305 /* 10306 ** CAPI3REF: Recover snapshots from a wal file 10307 ** METHOD: sqlite3_snapshot 10308 ** 10309 ** If a [WAL file] remains on disk after all database connections close 10310 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10311 ** or because the last process to have the database opened exited without 10312 ** calling [sqlite3_close()]) and a new connection is subsequently opened 10313 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10314 ** will only be able to open the last transaction added to the WAL file 10315 ** even though the WAL file contains other valid transactions. 10316 ** 10317 ** This function attempts to scan the WAL file associated with database zDb 10318 ** of database handle db and make all valid snapshots available to 10319 ** sqlite3_snapshot_open(). It is an error if there is already a read 10320 ** transaction open on the database, or if the database is not a WAL mode 10321 ** database. 10322 ** 10323 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10324 ** 10325 ** This interface is only available if SQLite is compiled with the 10326 ** [SQLITE_ENABLE_SNAPSHOT] option. 10327 */ 10328 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10329 10330 /* 10331 ** CAPI3REF: Serialize a database 10332 ** 10333 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 10334 ** that is a serialization of the S database on [database connection] D. 10335 ** If P is not a NULL pointer, then the size of the database in bytes 10336 ** is written into *P. 10337 ** 10338 ** For an ordinary on-disk database file, the serialization is just a 10339 ** copy of the disk file. For an in-memory database or a "TEMP" database, 10340 ** the serialization is the same sequence of bytes which would be written 10341 ** to disk if that database where backed up to disk. 10342 ** 10343 ** The usual case is that sqlite3_serialize() copies the serialization of 10344 ** the database into memory obtained from [sqlite3_malloc64()] and returns 10345 ** a pointer to that memory. The caller is responsible for freeing the 10346 ** returned value to avoid a memory leak. However, if the F argument 10347 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10348 ** are made, and the sqlite3_serialize() function will return a pointer 10349 ** to the contiguous memory representation of the database that SQLite 10350 ** is currently using for that database, or NULL if the no such contiguous 10351 ** memory representation of the database exists. A contiguous memory 10352 ** representation of the database will usually only exist if there has 10353 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10354 ** values of D and S. 10355 ** The size of the database is written into *P even if the 10356 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10357 ** of the database exists. 10358 ** 10359 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10360 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10361 ** allocation error occurs. 10362 ** 10363 ** This interface is omitted if SQLite is compiled with the 10364 ** [SQLITE_OMIT_DESERIALIZE] option. 10365 */ 10366 SQLITE_API unsigned char *sqlite3_serialize( 10367 sqlite3 *db, /* The database connection */ 10368 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10369 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10370 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10371 ); 10372 10373 /* 10374 ** CAPI3REF: Flags for sqlite3_serialize 10375 ** 10376 ** Zero or more of the following constants can be OR-ed together for 10377 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 10378 ** 10379 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10380 ** a pointer to contiguous in-memory database that it is currently using, 10381 ** without making a copy of the database. If SQLite is not currently using 10382 ** a contiguous in-memory database, then this option causes 10383 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10384 ** using a contiguous in-memory database if it has been initialized by a 10385 ** prior call to [sqlite3_deserialize()]. 10386 */ 10387 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10388 10389 /* 10390 ** CAPI3REF: Deserialize a database 10391 ** 10392 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10393 ** [database connection] D to disconnect from database S and then 10394 ** reopen S as an in-memory database based on the serialization contained 10395 ** in P. The serialized database P is N bytes in size. M is the size of 10396 ** the buffer P, which might be larger than N. If M is larger than N, and 10397 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10398 ** permitted to add content to the in-memory database as long as the total 10399 ** size does not exceed M bytes. 10400 ** 10401 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10402 ** invoke sqlite3_free() on the serialization buffer when the database 10403 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10404 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 10405 ** if writes on the database cause it to grow larger than M bytes. 10406 ** 10407 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 10408 ** database is currently in a read transaction or is involved in a backup 10409 ** operation. 10410 ** 10411 ** It is not possible to deserialized into the TEMP database. If the 10412 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 10413 ** function returns SQLITE_ERROR. 10414 ** 10415 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 10416 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 10417 ** [sqlite3_free()] is invoked on argument P prior to returning. 10418 ** 10419 ** This interface is omitted if SQLite is compiled with the 10420 ** [SQLITE_OMIT_DESERIALIZE] option. 10421 */ 10422 SQLITE_API int sqlite3_deserialize( 10423 sqlite3 *db, /* The database connection */ 10424 const char *zSchema, /* Which DB to reopen with the deserialization */ 10425 unsigned char *pData, /* The serialized database content */ 10426 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 10427 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 10428 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 10429 ); 10430 10431 /* 10432 ** CAPI3REF: Flags for sqlite3_deserialize() 10433 ** 10434 ** The following are allowed values for 6th argument (the F argument) to 10435 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 10436 ** 10437 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 10438 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 10439 ** and that SQLite should take ownership of this memory and automatically 10440 ** free it when it has finished using it. Without this flag, the caller 10441 ** is responsible for freeing any dynamically allocated memory. 10442 ** 10443 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 10444 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 10445 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 10446 ** Without this flag, the deserialized database cannot increase in size beyond 10447 ** the number of bytes specified by the M parameter. 10448 ** 10449 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 10450 ** should be treated as read-only. 10451 */ 10452 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 10453 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 10454 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 10455 10456 /* 10457 ** Undo the hack that converts floating point types to integer for 10458 ** builds on processors without floating point support. 10459 */ 10460 #ifdef SQLITE_OMIT_FLOATING_POINT 10461 # undef double 10462 #endif 10463 10464 #ifdef __cplusplus 10465 } /* End of the 'extern "C"' block */ 10466 #endif 10467 #endif /* SQLITE3_H */ 10468 10469 /******** Begin file sqlite3rtree.h *********/ 10470 /* 10471 ** 2010 August 30 10472 ** 10473 ** The author disclaims copyright to this source code. In place of 10474 ** a legal notice, here is a blessing: 10475 ** 10476 ** May you do good and not evil. 10477 ** May you find forgiveness for yourself and forgive others. 10478 ** May you share freely, never taking more than you give. 10479 ** 10480 ************************************************************************* 10481 */ 10482 10483 #ifndef _SQLITE3RTREE_H_ 10484 #define _SQLITE3RTREE_H_ 10485 10486 10487 #ifdef __cplusplus 10488 extern "C" { 10489 #endif 10490 10491 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 10492 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 10493 10494 /* The double-precision datatype used by RTree depends on the 10495 ** SQLITE_RTREE_INT_ONLY compile-time option. 10496 */ 10497 #ifdef SQLITE_RTREE_INT_ONLY 10498 typedef sqlite3_int64 sqlite3_rtree_dbl; 10499 #else 10500 typedef double sqlite3_rtree_dbl; 10501 #endif 10502 10503 /* 10504 ** Register a geometry callback named zGeom that can be used as part of an 10505 ** R-Tree geometry query as follows: 10506 ** 10507 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 10508 */ 10509 SQLITE_API int sqlite3_rtree_geometry_callback( 10510 sqlite3 *db, 10511 const char *zGeom, 10512 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 10513 void *pContext 10514 ); 10515 10516 10517 /* 10518 ** A pointer to a structure of the following type is passed as the first 10519 ** argument to callbacks registered using rtree_geometry_callback(). 10520 */ 10521 struct sqlite3_rtree_geometry { 10522 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 10523 int nParam; /* Size of array aParam[] */ 10524 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 10525 void *pUser; /* Callback implementation user data */ 10526 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 10527 }; 10528 10529 /* 10530 ** Register a 2nd-generation geometry callback named zScore that can be 10531 ** used as part of an R-Tree geometry query as follows: 10532 ** 10533 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 10534 */ 10535 SQLITE_API int sqlite3_rtree_query_callback( 10536 sqlite3 *db, 10537 const char *zQueryFunc, 10538 int (*xQueryFunc)(sqlite3_rtree_query_info*), 10539 void *pContext, 10540 void (*xDestructor)(void*) 10541 ); 10542 10543 10544 /* 10545 ** A pointer to a structure of the following type is passed as the 10546 ** argument to scored geometry callback registered using 10547 ** sqlite3_rtree_query_callback(). 10548 ** 10549 ** Note that the first 5 fields of this structure are identical to 10550 ** sqlite3_rtree_geometry. This structure is a subclass of 10551 ** sqlite3_rtree_geometry. 10552 */ 10553 struct sqlite3_rtree_query_info { 10554 void *pContext; /* pContext from when function registered */ 10555 int nParam; /* Number of function parameters */ 10556 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 10557 void *pUser; /* callback can use this, if desired */ 10558 void (*xDelUser)(void*); /* function to free pUser */ 10559 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 10560 unsigned int *anQueue; /* Number of pending entries in the queue */ 10561 int nCoord; /* Number of coordinates */ 10562 int iLevel; /* Level of current node or entry */ 10563 int mxLevel; /* The largest iLevel value in the tree */ 10564 sqlite3_int64 iRowid; /* Rowid for current entry */ 10565 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 10566 int eParentWithin; /* Visibility of parent node */ 10567 int eWithin; /* OUT: Visibility */ 10568 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 10569 /* The following fields are only available in 3.8.11 and later */ 10570 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 10571 }; 10572 10573 /* 10574 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10575 */ 10576 #define NOT_WITHIN 0 /* Object completely outside of query region */ 10577 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10578 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 10579 10580 10581 #ifdef __cplusplus 10582 } /* end of the 'extern "C"' block */ 10583 #endif 10584 10585 #endif /* ifndef _SQLITE3RTREE_H_ */ 10586 10587 /******** End of sqlite3rtree.h *********/ 10588 /******** Begin file sqlite3session.h *********/ 10589 10590 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10591 #define __SQLITESESSION_H_ 1 10592 10593 /* 10594 ** Make sure we can call this stuff from C++. 10595 */ 10596 #ifdef __cplusplus 10597 extern "C" { 10598 #endif 10599 10600 10601 /* 10602 ** CAPI3REF: Session Object Handle 10603 ** 10604 ** An instance of this object is a [session] that can be used to 10605 ** record changes to a database. 10606 */ 10607 typedef struct sqlite3_session sqlite3_session; 10608 10609 /* 10610 ** CAPI3REF: Changeset Iterator Handle 10611 ** 10612 ** An instance of this object acts as a cursor for iterating 10613 ** over the elements of a [changeset] or [patchset]. 10614 */ 10615 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10616 10617 /* 10618 ** CAPI3REF: Create A New Session Object 10619 ** CONSTRUCTOR: sqlite3_session 10620 ** 10621 ** Create a new session object attached to database handle db. If successful, 10622 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 10623 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10624 ** error code (e.g. SQLITE_NOMEM) is returned. 10625 ** 10626 ** It is possible to create multiple session objects attached to a single 10627 ** database handle. 10628 ** 10629 ** Session objects created using this function should be deleted using the 10630 ** [sqlite3session_delete()] function before the database handle that they 10631 ** are attached to is itself closed. If the database handle is closed before 10632 ** the session object is deleted, then the results of calling any session 10633 ** module function, including [sqlite3session_delete()] on the session object 10634 ** are undefined. 10635 ** 10636 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10637 ** is not possible for an application to register a pre-update hook on a 10638 ** database handle that has one or more session objects attached. Nor is 10639 ** it possible to create a session object attached to a database handle for 10640 ** which a pre-update hook is already defined. The results of attempting 10641 ** either of these things are undefined. 10642 ** 10643 ** The session object will be used to create changesets for tables in 10644 ** database zDb, where zDb is either "main", or "temp", or the name of an 10645 ** attached database. It is not an error if database zDb is not attached 10646 ** to the database when the session object is created. 10647 */ 10648 SQLITE_API int sqlite3session_create( 10649 sqlite3 *db, /* Database handle */ 10650 const char *zDb, /* Name of db (e.g. "main") */ 10651 sqlite3_session **ppSession /* OUT: New session object */ 10652 ); 10653 10654 /* 10655 ** CAPI3REF: Delete A Session Object 10656 ** DESTRUCTOR: sqlite3_session 10657 ** 10658 ** Delete a session object previously allocated using 10659 ** [sqlite3session_create()]. Once a session object has been deleted, the 10660 ** results of attempting to use pSession with any other session module 10661 ** function are undefined. 10662 ** 10663 ** Session objects must be deleted before the database handle to which they 10664 ** are attached is closed. Refer to the documentation for 10665 ** [sqlite3session_create()] for details. 10666 */ 10667 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10668 10669 /* 10670 ** CAPIREF: Conigure a Session Object 10671 ** METHOD: sqlite3_session 10672 ** 10673 ** This method is used to configure a session object after it has been 10674 ** created. At present the only valid value for the second parameter is 10675 ** [SQLITE_SESSION_OBJCONFIG_SIZE]. 10676 ** 10677 ** Arguments for sqlite3session_object_config() 10678 ** 10679 ** The following values may passed as the the 4th parameter to 10680 ** sqlite3session_object_config(). 10681 ** 10682 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 10683 ** This option is used to set, clear or query the flag that enables 10684 ** the [sqlite3session_changeset_size()] API. Because it imposes some 10685 ** computational overhead, this API is disabled by default. Argument 10686 ** pArg must point to a value of type (int). If the value is initially 10687 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 10688 ** is greater than 0, then the same API is enabled. Or, if the initial 10689 ** value is less than zero, no change is made. In all cases the (int) 10690 ** variable is set to 1 if the sqlite3session_changeset_size() API is 10691 ** enabled following the current call, or 0 otherwise. 10692 ** 10693 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 10694 ** the first table has been attached to the session object. 10695 */ 10696 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 10697 10698 /* 10699 */ 10700 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 10701 10702 /* 10703 ** CAPI3REF: Enable Or Disable A Session Object 10704 ** METHOD: sqlite3_session 10705 ** 10706 ** Enable or disable the recording of changes by a session object. When 10707 ** enabled, a session object records changes made to the database. When 10708 ** disabled - it does not. A newly created session object is enabled. 10709 ** Refer to the documentation for [sqlite3session_changeset()] for further 10710 ** details regarding how enabling and disabling a session object affects 10711 ** the eventual changesets. 10712 ** 10713 ** Passing zero to this function disables the session. Passing a value 10714 ** greater than zero enables it. Passing a value less than zero is a 10715 ** no-op, and may be used to query the current state of the session. 10716 ** 10717 ** The return value indicates the final state of the session object: 0 if 10718 ** the session is disabled, or 1 if it is enabled. 10719 */ 10720 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10721 10722 /* 10723 ** CAPI3REF: Set Or Clear the Indirect Change Flag 10724 ** METHOD: sqlite3_session 10725 ** 10726 ** Each change recorded by a session object is marked as either direct or 10727 ** indirect. A change is marked as indirect if either: 10728 ** 10729 ** <ul> 10730 ** <li> The session object "indirect" flag is set when the change is 10731 ** made, or 10732 ** <li> The change is made by an SQL trigger or foreign key action 10733 ** instead of directly as a result of a users SQL statement. 10734 ** </ul> 10735 ** 10736 ** If a single row is affected by more than one operation within a session, 10737 ** then the change is considered indirect if all operations meet the criteria 10738 ** for an indirect change above, or direct otherwise. 10739 ** 10740 ** This function is used to set, clear or query the session object indirect 10741 ** flag. If the second argument passed to this function is zero, then the 10742 ** indirect flag is cleared. If it is greater than zero, the indirect flag 10743 ** is set. Passing a value less than zero does not modify the current value 10744 ** of the indirect flag, and may be used to query the current state of the 10745 ** indirect flag for the specified session object. 10746 ** 10747 ** The return value indicates the final state of the indirect flag: 0 if 10748 ** it is clear, or 1 if it is set. 10749 */ 10750 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10751 10752 /* 10753 ** CAPI3REF: Attach A Table To A Session Object 10754 ** METHOD: sqlite3_session 10755 ** 10756 ** If argument zTab is not NULL, then it is the name of a table to attach 10757 ** to the session object passed as the first argument. All subsequent changes 10758 ** made to the table while the session object is enabled will be recorded. See 10759 ** documentation for [sqlite3session_changeset()] for further details. 10760 ** 10761 ** Or, if argument zTab is NULL, then changes are recorded for all tables 10762 ** in the database. If additional tables are added to the database (by 10763 ** executing "CREATE TABLE" statements) after this call is made, changes for 10764 ** the new tables are also recorded. 10765 ** 10766 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10767 ** defined as part of their CREATE TABLE statement. It does not matter if the 10768 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10769 ** KEY may consist of a single column, or may be a composite key. 10770 ** 10771 ** It is not an error if the named table does not exist in the database. Nor 10772 ** is it an error if the named table does not have a PRIMARY KEY. However, 10773 ** no changes will be recorded in either of these scenarios. 10774 ** 10775 ** Changes are not recorded for individual rows that have NULL values stored 10776 ** in one or more of their PRIMARY KEY columns. 10777 ** 10778 ** SQLITE_OK is returned if the call completes without error. Or, if an error 10779 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10780 ** 10781 ** <h3>Special sqlite_stat1 Handling</h3> 10782 ** 10783 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10784 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10785 ** <pre> 10786 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10787 ** </pre> 10788 ** 10789 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10790 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10791 ** are recorded for rows for which (idx IS NULL) is true. However, for such 10792 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 10793 ** patchset instead of a NULL value. This allows such changesets to be 10794 ** manipulated by legacy implementations of sqlite3changeset_invert(), 10795 ** concat() and similar. 10796 ** 10797 ** The sqlite3changeset_apply() function automatically converts the 10798 ** zero-length blob back to a NULL value when updating the sqlite_stat1 10799 ** table. However, if the application calls sqlite3changeset_new(), 10800 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10801 ** iterator directly (including on a changeset iterator passed to a 10802 ** conflict-handler callback) then the X'' value is returned. The application 10803 ** must translate X'' to NULL itself if required. 10804 ** 10805 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10806 ** changes made to the sqlite_stat1 table. Legacy versions of the 10807 ** sqlite3changeset_apply() function silently ignore any modifications to the 10808 ** sqlite_stat1 table that are part of a changeset or patchset. 10809 */ 10810 SQLITE_API int sqlite3session_attach( 10811 sqlite3_session *pSession, /* Session object */ 10812 const char *zTab /* Table name */ 10813 ); 10814 10815 /* 10816 ** CAPI3REF: Set a table filter on a Session Object. 10817 ** METHOD: sqlite3_session 10818 ** 10819 ** The second argument (xFilter) is the "filter callback". For changes to rows 10820 ** in tables that are not attached to the Session object, the filter is called 10821 ** to determine whether changes to the table's rows should be tracked or not. 10822 ** If xFilter returns 0, changes are not tracked. Note that once a table is 10823 ** attached, xFilter will not be called again. 10824 */ 10825 SQLITE_API void sqlite3session_table_filter( 10826 sqlite3_session *pSession, /* Session object */ 10827 int(*xFilter)( 10828 void *pCtx, /* Copy of third arg to _filter_table() */ 10829 const char *zTab /* Table name */ 10830 ), 10831 void *pCtx /* First argument passed to xFilter */ 10832 ); 10833 10834 /* 10835 ** CAPI3REF: Generate A Changeset From A Session Object 10836 ** METHOD: sqlite3_session 10837 ** 10838 ** Obtain a changeset containing changes to the tables attached to the 10839 ** session object passed as the first argument. If successful, 10840 ** set *ppChangeset to point to a buffer containing the changeset 10841 ** and *pnChangeset to the size of the changeset in bytes before returning 10842 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10843 ** zero and return an SQLite error code. 10844 ** 10845 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10846 ** each representing a change to a single row of an attached table. An INSERT 10847 ** change contains the values of each field of a new database row. A DELETE 10848 ** contains the original values of each field of a deleted database row. An 10849 ** UPDATE change contains the original values of each field of an updated 10850 ** database row along with the updated values for each updated non-primary-key 10851 ** column. It is not possible for an UPDATE change to represent a change that 10852 ** modifies the values of primary key columns. If such a change is made, it 10853 ** is represented in a changeset as a DELETE followed by an INSERT. 10854 ** 10855 ** Changes are not recorded for rows that have NULL values stored in one or 10856 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10857 ** no corresponding change is present in the changesets returned by this 10858 ** function. If an existing row with one or more NULL values stored in 10859 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10860 ** only an INSERT is appears in the changeset. Similarly, if an existing row 10861 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 10862 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10863 ** DELETE change only. 10864 ** 10865 ** The contents of a changeset may be traversed using an iterator created 10866 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 10867 ** a database with a compatible schema using the [sqlite3changeset_apply()] 10868 ** API. 10869 ** 10870 ** Within a changeset generated by this function, all changes related to a 10871 ** single table are grouped together. In other words, when iterating through 10872 ** a changeset or when applying a changeset to a database, all changes related 10873 ** to a single table are processed before moving on to the next table. Tables 10874 ** are sorted in the same order in which they were attached (or auto-attached) 10875 ** to the sqlite3_session object. The order in which the changes related to 10876 ** a single table are stored is undefined. 10877 ** 10878 ** Following a successful call to this function, it is the responsibility of 10879 ** the caller to eventually free the buffer that *ppChangeset points to using 10880 ** [sqlite3_free()]. 10881 ** 10882 ** <h3>Changeset Generation</h3> 10883 ** 10884 ** Once a table has been attached to a session object, the session object 10885 ** records the primary key values of all new rows inserted into the table. 10886 ** It also records the original primary key and other column values of any 10887 ** deleted or updated rows. For each unique primary key value, data is only 10888 ** recorded once - the first time a row with said primary key is inserted, 10889 ** updated or deleted in the lifetime of the session. 10890 ** 10891 ** There is one exception to the previous paragraph: when a row is inserted, 10892 ** updated or deleted, if one or more of its primary key columns contain a 10893 ** NULL value, no record of the change is made. 10894 ** 10895 ** The session object therefore accumulates two types of records - those 10896 ** that consist of primary key values only (created when the user inserts 10897 ** a new record) and those that consist of the primary key values and the 10898 ** original values of other table columns (created when the users deletes 10899 ** or updates a record). 10900 ** 10901 ** When this function is called, the requested changeset is created using 10902 ** both the accumulated records and the current contents of the database 10903 ** file. Specifically: 10904 ** 10905 ** <ul> 10906 ** <li> For each record generated by an insert, the database is queried 10907 ** for a row with a matching primary key. If one is found, an INSERT 10908 ** change is added to the changeset. If no such row is found, no change 10909 ** is added to the changeset. 10910 ** 10911 ** <li> For each record generated by an update or delete, the database is 10912 ** queried for a row with a matching primary key. If such a row is 10913 ** found and one or more of the non-primary key fields have been 10914 ** modified from their original values, an UPDATE change is added to 10915 ** the changeset. Or, if no such row is found in the table, a DELETE 10916 ** change is added to the changeset. If there is a row with a matching 10917 ** primary key in the database, but all fields contain their original 10918 ** values, no change is added to the changeset. 10919 ** </ul> 10920 ** 10921 ** This means, amongst other things, that if a row is inserted and then later 10922 ** deleted while a session object is active, neither the insert nor the delete 10923 ** will be present in the changeset. Or if a row is deleted and then later a 10924 ** row with the same primary key values inserted while a session object is 10925 ** active, the resulting changeset will contain an UPDATE change instead of 10926 ** a DELETE and an INSERT. 10927 ** 10928 ** When a session object is disabled (see the [sqlite3session_enable()] API), 10929 ** it does not accumulate records when rows are inserted, updated or deleted. 10930 ** This may appear to have some counter-intuitive effects if a single row 10931 ** is written to more than once during a session. For example, if a row 10932 ** is inserted while a session object is enabled, then later deleted while 10933 ** the same session object is disabled, no INSERT record will appear in the 10934 ** changeset, even though the delete took place while the session was disabled. 10935 ** Or, if one field of a row is updated while a session is disabled, and 10936 ** another field of the same row is updated while the session is enabled, the 10937 ** resulting changeset will contain an UPDATE change that updates both fields. 10938 */ 10939 SQLITE_API int sqlite3session_changeset( 10940 sqlite3_session *pSession, /* Session object */ 10941 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 10942 void **ppChangeset /* OUT: Buffer containing changeset */ 10943 ); 10944 10945 /* 10946 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 10947 ** METHOD: sqlite3_session 10948 ** 10949 ** By default, this function always returns 0. For it to return 10950 ** a useful result, the sqlite3_session object must have been configured 10951 ** to enable this API using sqlite3session_object_config() with the 10952 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 10953 ** 10954 ** When enabled, this function returns an upper limit, in bytes, for the size 10955 ** of the changeset that might be produced if sqlite3session_changeset() were 10956 ** called. The final changeset size might be equal to or smaller than the 10957 ** size in bytes returned by this function. 10958 */ 10959 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 10960 10961 /* 10962 ** CAPI3REF: Load The Difference Between Tables Into A Session 10963 ** METHOD: sqlite3_session 10964 ** 10965 ** If it is not already attached to the session object passed as the first 10966 ** argument, this function attaches table zTbl in the same manner as the 10967 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 10968 ** does not have a primary key, this function is a no-op (but does not return 10969 ** an error). 10970 ** 10971 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 10972 ** attached to the same database handle as the session object that contains 10973 ** a table compatible with the table attached to the session by this function. 10974 ** A table is considered compatible if it: 10975 ** 10976 ** <ul> 10977 ** <li> Has the same name, 10978 ** <li> Has the same set of columns declared in the same order, and 10979 ** <li> Has the same PRIMARY KEY definition. 10980 ** </ul> 10981 ** 10982 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 10983 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 10984 ** but no changes are added to the session object. As with other session 10985 ** APIs, tables without PRIMARY KEYs are simply ignored. 10986 ** 10987 ** This function adds a set of changes to the session object that could be 10988 ** used to update the table in database zFrom (call this the "from-table") 10989 ** so that its content is the same as the table attached to the session 10990 ** object (call this the "to-table"). Specifically: 10991 ** 10992 ** <ul> 10993 ** <li> For each row (primary key) that exists in the to-table but not in 10994 ** the from-table, an INSERT record is added to the session object. 10995 ** 10996 ** <li> For each row (primary key) that exists in the to-table but not in 10997 ** the from-table, a DELETE record is added to the session object. 10998 ** 10999 ** <li> For each row (primary key) that exists in both tables, but features 11000 ** different non-PK values in each, an UPDATE record is added to the 11001 ** session. 11002 ** </ul> 11003 ** 11004 ** To clarify, if this function is called and then a changeset constructed 11005 ** using [sqlite3session_changeset()], then after applying that changeset to 11006 ** database zFrom the contents of the two compatible tables would be 11007 ** identical. 11008 ** 11009 ** It an error if database zFrom does not exist or does not contain the 11010 ** required compatible table. 11011 ** 11012 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 11013 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 11014 ** may be set to point to a buffer containing an English language error 11015 ** message. It is the responsibility of the caller to free this buffer using 11016 ** sqlite3_free(). 11017 */ 11018 SQLITE_API int sqlite3session_diff( 11019 sqlite3_session *pSession, 11020 const char *zFromDb, 11021 const char *zTbl, 11022 char **pzErrMsg 11023 ); 11024 11025 11026 /* 11027 ** CAPI3REF: Generate A Patchset From A Session Object 11028 ** METHOD: sqlite3_session 11029 ** 11030 ** The differences between a patchset and a changeset are that: 11031 ** 11032 ** <ul> 11033 ** <li> DELETE records consist of the primary key fields only. The 11034 ** original values of other fields are omitted. 11035 ** <li> The original values of any modified fields are omitted from 11036 ** UPDATE records. 11037 ** </ul> 11038 ** 11039 ** A patchset blob may be used with up to date versions of all 11040 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 11041 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 11042 ** attempting to use a patchset blob with old versions of the 11043 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 11044 ** 11045 ** Because the non-primary key "old.*" fields are omitted, no 11046 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 11047 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 11048 ** in the same way as for changesets. 11049 ** 11050 ** Changes within a patchset are ordered in the same way as for changesets 11051 ** generated by the sqlite3session_changeset() function (i.e. all changes for 11052 ** a single table are grouped together, tables appear in the order in which 11053 ** they were attached to the session object). 11054 */ 11055 SQLITE_API int sqlite3session_patchset( 11056 sqlite3_session *pSession, /* Session object */ 11057 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11058 void **ppPatchset /* OUT: Buffer containing patchset */ 11059 ); 11060 11061 /* 11062 ** CAPI3REF: Test if a changeset has recorded any changes. 11063 ** 11064 ** Return non-zero if no changes to attached tables have been recorded by 11065 ** the session object passed as the first argument. Otherwise, if one or 11066 ** more changes have been recorded, return zero. 11067 ** 11068 ** Even if this function returns zero, it is possible that calling 11069 ** [sqlite3session_changeset()] on the session handle may still return a 11070 ** changeset that contains no changes. This can happen when a row in 11071 ** an attached table is modified and then later on the original values 11072 ** are restored. However, if this function returns non-zero, then it is 11073 ** guaranteed that a call to sqlite3session_changeset() will return a 11074 ** changeset containing zero changes. 11075 */ 11076 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11077 11078 /* 11079 ** CAPI3REF: Query for the amount of heap memory used by a session object. 11080 ** 11081 ** This API returns the total amount of heap memory in bytes currently 11082 ** used by the session object passed as the only argument. 11083 */ 11084 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11085 11086 /* 11087 ** CAPI3REF: Create An Iterator To Traverse A Changeset 11088 ** CONSTRUCTOR: sqlite3_changeset_iter 11089 ** 11090 ** Create an iterator used to iterate through the contents of a changeset. 11091 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11092 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11093 ** SQLite error code is returned. 11094 ** 11095 ** The following functions can be used to advance and query a changeset 11096 ** iterator created by this function: 11097 ** 11098 ** <ul> 11099 ** <li> [sqlite3changeset_next()] 11100 ** <li> [sqlite3changeset_op()] 11101 ** <li> [sqlite3changeset_new()] 11102 ** <li> [sqlite3changeset_old()] 11103 ** </ul> 11104 ** 11105 ** It is the responsibility of the caller to eventually destroy the iterator 11106 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11107 ** changeset (pChangeset) must remain valid until after the iterator is 11108 ** destroyed. 11109 ** 11110 ** Assuming the changeset blob was created by one of the 11111 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11112 ** [sqlite3changeset_invert()] functions, all changes within the changeset 11113 ** that apply to a single table are grouped together. This means that when 11114 ** an application iterates through a changeset using an iterator created by 11115 ** this function, all changes that relate to a single table are visited 11116 ** consecutively. There is no chance that the iterator will visit a change 11117 ** the applies to table X, then one for table Y, and then later on visit 11118 ** another change for table X. 11119 ** 11120 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11121 ** may be modified by passing a combination of 11122 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11123 ** 11124 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11125 ** and therefore subject to change. 11126 */ 11127 SQLITE_API int sqlite3changeset_start( 11128 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11129 int nChangeset, /* Size of changeset blob in bytes */ 11130 void *pChangeset /* Pointer to blob containing changeset */ 11131 ); 11132 SQLITE_API int sqlite3changeset_start_v2( 11133 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11134 int nChangeset, /* Size of changeset blob in bytes */ 11135 void *pChangeset, /* Pointer to blob containing changeset */ 11136 int flags /* SESSION_CHANGESETSTART_* flags */ 11137 ); 11138 11139 /* 11140 ** CAPI3REF: Flags for sqlite3changeset_start_v2 11141 ** 11142 ** The following flags may passed via the 4th parameter to 11143 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11144 ** 11145 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11146 ** Invert the changeset while iterating through it. This is equivalent to 11147 ** inverting a changeset using sqlite3changeset_invert() before applying it. 11148 ** It is an error to specify this flag with a patchset. 11149 */ 11150 #define SQLITE_CHANGESETSTART_INVERT 0x0002 11151 11152 11153 /* 11154 ** CAPI3REF: Advance A Changeset Iterator 11155 ** METHOD: sqlite3_changeset_iter 11156 ** 11157 ** This function may only be used with iterators created by the function 11158 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 11159 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11160 ** is returned and the call has no effect. 11161 ** 11162 ** Immediately after an iterator is created by sqlite3changeset_start(), it 11163 ** does not point to any change in the changeset. Assuming the changeset 11164 ** is not empty, the first call to this function advances the iterator to 11165 ** point to the first change in the changeset. Each subsequent call advances 11166 ** the iterator to point to the next change in the changeset (if any). If 11167 ** no error occurs and the iterator points to a valid change after a call 11168 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11169 ** Otherwise, if all changes in the changeset have already been visited, 11170 ** SQLITE_DONE is returned. 11171 ** 11172 ** If an error occurs, an SQLite error code is returned. Possible error 11173 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11174 ** SQLITE_NOMEM. 11175 */ 11176 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11177 11178 /* 11179 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11180 ** METHOD: sqlite3_changeset_iter 11181 ** 11182 ** The pIter argument passed to this function may either be an iterator 11183 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11184 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11185 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11186 ** is not the case, this function returns [SQLITE_MISUSE]. 11187 ** 11188 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11189 ** outputs are set through these pointers: 11190 ** 11191 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11192 ** depending on the type of change that the iterator currently points to; 11193 ** 11194 ** *pnCol is set to the number of columns in the table affected by the change; and 11195 ** 11196 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11197 ** the name of the table affected by the current change. The buffer remains 11198 ** valid until either sqlite3changeset_next() is called on the iterator 11199 ** or until the conflict-handler function returns. 11200 ** 11201 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11202 ** is an indirect change, or false (0) otherwise. See the documentation for 11203 ** [sqlite3session_indirect()] for a description of direct and indirect 11204 ** changes. 11205 ** 11206 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11207 ** SQLite error code is returned. The values of the output variables may not 11208 ** be trusted in this case. 11209 */ 11210 SQLITE_API int sqlite3changeset_op( 11211 sqlite3_changeset_iter *pIter, /* Iterator object */ 11212 const char **pzTab, /* OUT: Pointer to table name */ 11213 int *pnCol, /* OUT: Number of columns in table */ 11214 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11215 int *pbIndirect /* OUT: True for an 'indirect' change */ 11216 ); 11217 11218 /* 11219 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 11220 ** METHOD: sqlite3_changeset_iter 11221 ** 11222 ** For each modified table, a changeset includes the following: 11223 ** 11224 ** <ul> 11225 ** <li> The number of columns in the table, and 11226 ** <li> Which of those columns make up the tables PRIMARY KEY. 11227 ** </ul> 11228 ** 11229 ** This function is used to find which columns comprise the PRIMARY KEY of 11230 ** the table modified by the change that iterator pIter currently points to. 11231 ** If successful, *pabPK is set to point to an array of nCol entries, where 11232 ** nCol is the number of columns in the table. Elements of *pabPK are set to 11233 ** 0x01 if the corresponding column is part of the tables primary key, or 11234 ** 0x00 if it is not. 11235 ** 11236 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 11237 ** in the table. 11238 ** 11239 ** If this function is called when the iterator does not point to a valid 11240 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 11241 ** SQLITE_OK is returned and the output variables populated as described 11242 ** above. 11243 */ 11244 SQLITE_API int sqlite3changeset_pk( 11245 sqlite3_changeset_iter *pIter, /* Iterator object */ 11246 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 11247 int *pnCol /* OUT: Number of entries in output array */ 11248 ); 11249 11250 /* 11251 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 11252 ** METHOD: sqlite3_changeset_iter 11253 ** 11254 ** The pIter argument passed to this function may either be an iterator 11255 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11256 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11257 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11258 ** Furthermore, it may only be called if the type of change that the iterator 11259 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 11260 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11261 ** 11262 ** Argument iVal must be greater than or equal to 0, and less than the number 11263 ** of columns in the table affected by the current change. Otherwise, 11264 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11265 ** 11266 ** If successful, this function sets *ppValue to point to a protected 11267 ** sqlite3_value object containing the iVal'th value from the vector of 11268 ** original row values stored as part of the UPDATE or DELETE change and 11269 ** returns SQLITE_OK. The name of the function comes from the fact that this 11270 ** is similar to the "old.*" columns available to update or delete triggers. 11271 ** 11272 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11273 ** is returned and *ppValue is set to NULL. 11274 */ 11275 SQLITE_API int sqlite3changeset_old( 11276 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11277 int iVal, /* Column number */ 11278 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 11279 ); 11280 11281 /* 11282 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 11283 ** METHOD: sqlite3_changeset_iter 11284 ** 11285 ** The pIter argument passed to this function may either be an iterator 11286 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11287 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11288 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11289 ** Furthermore, it may only be called if the type of change that the iterator 11290 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 11291 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11292 ** 11293 ** Argument iVal must be greater than or equal to 0, and less than the number 11294 ** of columns in the table affected by the current change. Otherwise, 11295 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11296 ** 11297 ** If successful, this function sets *ppValue to point to a protected 11298 ** sqlite3_value object containing the iVal'th value from the vector of 11299 ** new row values stored as part of the UPDATE or INSERT change and 11300 ** returns SQLITE_OK. If the change is an UPDATE and does not include 11301 ** a new value for the requested column, *ppValue is set to NULL and 11302 ** SQLITE_OK returned. The name of the function comes from the fact that 11303 ** this is similar to the "new.*" columns available to update or delete 11304 ** triggers. 11305 ** 11306 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11307 ** is returned and *ppValue is set to NULL. 11308 */ 11309 SQLITE_API int sqlite3changeset_new( 11310 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11311 int iVal, /* Column number */ 11312 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 11313 ); 11314 11315 /* 11316 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 11317 ** METHOD: sqlite3_changeset_iter 11318 ** 11319 ** This function should only be used with iterator objects passed to a 11320 ** conflict-handler callback by [sqlite3changeset_apply()] with either 11321 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 11322 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 11323 ** is set to NULL. 11324 ** 11325 ** Argument iVal must be greater than or equal to 0, and less than the number 11326 ** of columns in the table affected by the current change. Otherwise, 11327 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11328 ** 11329 ** If successful, this function sets *ppValue to point to a protected 11330 ** sqlite3_value object containing the iVal'th value from the 11331 ** "conflicting row" associated with the current conflict-handler callback 11332 ** and returns SQLITE_OK. 11333 ** 11334 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11335 ** is returned and *ppValue is set to NULL. 11336 */ 11337 SQLITE_API int sqlite3changeset_conflict( 11338 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11339 int iVal, /* Column number */ 11340 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 11341 ); 11342 11343 /* 11344 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 11345 ** METHOD: sqlite3_changeset_iter 11346 ** 11347 ** This function may only be called with an iterator passed to an 11348 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 11349 ** it sets the output variable to the total number of known foreign key 11350 ** violations in the destination database and returns SQLITE_OK. 11351 ** 11352 ** In all other cases this function returns SQLITE_MISUSE. 11353 */ 11354 SQLITE_API int sqlite3changeset_fk_conflicts( 11355 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11356 int *pnOut /* OUT: Number of FK violations */ 11357 ); 11358 11359 11360 /* 11361 ** CAPI3REF: Finalize A Changeset Iterator 11362 ** METHOD: sqlite3_changeset_iter 11363 ** 11364 ** This function is used to finalize an iterator allocated with 11365 ** [sqlite3changeset_start()]. 11366 ** 11367 ** This function should only be called on iterators created using the 11368 ** [sqlite3changeset_start()] function. If an application calls this 11369 ** function with an iterator passed to a conflict-handler by 11370 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 11371 ** call has no effect. 11372 ** 11373 ** If an error was encountered within a call to an sqlite3changeset_xxx() 11374 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 11375 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 11376 ** to that error is returned by this function. Otherwise, SQLITE_OK is 11377 ** returned. This is to allow the following pattern (pseudo-code): 11378 ** 11379 ** <pre> 11380 ** sqlite3changeset_start(); 11381 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 11382 ** // Do something with change. 11383 ** } 11384 ** rc = sqlite3changeset_finalize(); 11385 ** if( rc!=SQLITE_OK ){ 11386 ** // An error has occurred 11387 ** } 11388 ** </pre> 11389 */ 11390 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 11391 11392 /* 11393 ** CAPI3REF: Invert A Changeset 11394 ** 11395 ** This function is used to "invert" a changeset object. Applying an inverted 11396 ** changeset to a database reverses the effects of applying the uninverted 11397 ** changeset. Specifically: 11398 ** 11399 ** <ul> 11400 ** <li> Each DELETE change is changed to an INSERT, and 11401 ** <li> Each INSERT change is changed to a DELETE, and 11402 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 11403 ** </ul> 11404 ** 11405 ** This function does not change the order in which changes appear within 11406 ** the changeset. It merely reverses the sense of each individual change. 11407 ** 11408 ** If successful, a pointer to a buffer containing the inverted changeset 11409 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 11410 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 11411 ** zeroed and an SQLite error code returned. 11412 ** 11413 ** It is the responsibility of the caller to eventually call sqlite3_free() 11414 ** on the *ppOut pointer to free the buffer allocation following a successful 11415 ** call to this function. 11416 ** 11417 ** WARNING/TODO: This function currently assumes that the input is a valid 11418 ** changeset. If it is not, the results are undefined. 11419 */ 11420 SQLITE_API int sqlite3changeset_invert( 11421 int nIn, const void *pIn, /* Input changeset */ 11422 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11423 ); 11424 11425 /* 11426 ** CAPI3REF: Concatenate Two Changeset Objects 11427 ** 11428 ** This function is used to concatenate two changesets, A and B, into a 11429 ** single changeset. The result is a changeset equivalent to applying 11430 ** changeset A followed by changeset B. 11431 ** 11432 ** This function combines the two input changesets using an 11433 ** sqlite3_changegroup object. Calling it produces similar results as the 11434 ** following code fragment: 11435 ** 11436 ** <pre> 11437 ** sqlite3_changegroup *pGrp; 11438 ** rc = sqlite3_changegroup_new(&pGrp); 11439 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 11440 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 11441 ** if( rc==SQLITE_OK ){ 11442 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 11443 ** }else{ 11444 ** *ppOut = 0; 11445 ** *pnOut = 0; 11446 ** } 11447 ** </pre> 11448 ** 11449 ** Refer to the sqlite3_changegroup documentation below for details. 11450 */ 11451 SQLITE_API int sqlite3changeset_concat( 11452 int nA, /* Number of bytes in buffer pA */ 11453 void *pA, /* Pointer to buffer containing changeset A */ 11454 int nB, /* Number of bytes in buffer pB */ 11455 void *pB, /* Pointer to buffer containing changeset B */ 11456 int *pnOut, /* OUT: Number of bytes in output changeset */ 11457 void **ppOut /* OUT: Buffer containing output changeset */ 11458 ); 11459 11460 11461 /* 11462 ** CAPI3REF: Changegroup Handle 11463 ** 11464 ** A changegroup is an object used to combine two or more 11465 ** [changesets] or [patchsets] 11466 */ 11467 typedef struct sqlite3_changegroup sqlite3_changegroup; 11468 11469 /* 11470 ** CAPI3REF: Create A New Changegroup Object 11471 ** CONSTRUCTOR: sqlite3_changegroup 11472 ** 11473 ** An sqlite3_changegroup object is used to combine two or more changesets 11474 ** (or patchsets) into a single changeset (or patchset). A single changegroup 11475 ** object may combine changesets or patchsets, but not both. The output is 11476 ** always in the same format as the input. 11477 ** 11478 ** If successful, this function returns SQLITE_OK and populates (*pp) with 11479 ** a pointer to a new sqlite3_changegroup object before returning. The caller 11480 ** should eventually free the returned object using a call to 11481 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 11482 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 11483 ** 11484 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 11485 ** 11486 ** <ul> 11487 ** <li> It is created using a call to sqlite3changegroup_new(). 11488 ** 11489 ** <li> Zero or more changesets (or patchsets) are added to the object 11490 ** by calling sqlite3changegroup_add(). 11491 ** 11492 ** <li> The result of combining all input changesets together is obtained 11493 ** by the application via a call to sqlite3changegroup_output(). 11494 ** 11495 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 11496 ** </ul> 11497 ** 11498 ** Any number of calls to add() and output() may be made between the calls to 11499 ** new() and delete(), and in any order. 11500 ** 11501 ** As well as the regular sqlite3changegroup_add() and 11502 ** sqlite3changegroup_output() functions, also available are the streaming 11503 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 11504 */ 11505 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 11506 11507 /* 11508 ** CAPI3REF: Add A Changeset To A Changegroup 11509 ** METHOD: sqlite3_changegroup 11510 ** 11511 ** Add all changes within the changeset (or patchset) in buffer pData (size 11512 ** nData bytes) to the changegroup. 11513 ** 11514 ** If the buffer contains a patchset, then all prior calls to this function 11515 ** on the same changegroup object must also have specified patchsets. Or, if 11516 ** the buffer contains a changeset, so must have the earlier calls to this 11517 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 11518 ** to the changegroup. 11519 ** 11520 ** Rows within the changeset and changegroup are identified by the values in 11521 ** their PRIMARY KEY columns. A change in the changeset is considered to 11522 ** apply to the same row as a change already present in the changegroup if 11523 ** the two rows have the same primary key. 11524 ** 11525 ** Changes to rows that do not already appear in the changegroup are 11526 ** simply copied into it. Or, if both the new changeset and the changegroup 11527 ** contain changes that apply to a single row, the final contents of the 11528 ** changegroup depends on the type of each change, as follows: 11529 ** 11530 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11531 ** <tr><th style="white-space:pre">Existing Change </th> 11532 ** <th style="white-space:pre">New Change </th> 11533 ** <th>Output Change 11534 ** <tr><td>INSERT <td>INSERT <td> 11535 ** The new change is ignored. This case does not occur if the new 11536 ** changeset was recorded immediately after the changesets already 11537 ** added to the changegroup. 11538 ** <tr><td>INSERT <td>UPDATE <td> 11539 ** The INSERT change remains in the changegroup. The values in the 11540 ** INSERT change are modified as if the row was inserted by the 11541 ** existing change and then updated according to the new change. 11542 ** <tr><td>INSERT <td>DELETE <td> 11543 ** The existing INSERT is removed from the changegroup. The DELETE is 11544 ** not added. 11545 ** <tr><td>UPDATE <td>INSERT <td> 11546 ** The new change is ignored. This case does not occur if the new 11547 ** changeset was recorded immediately after the changesets already 11548 ** added to the changegroup. 11549 ** <tr><td>UPDATE <td>UPDATE <td> 11550 ** The existing UPDATE remains within the changegroup. It is amended 11551 ** so that the accompanying values are as if the row was updated once 11552 ** by the existing change and then again by the new change. 11553 ** <tr><td>UPDATE <td>DELETE <td> 11554 ** The existing UPDATE is replaced by the new DELETE within the 11555 ** changegroup. 11556 ** <tr><td>DELETE <td>INSERT <td> 11557 ** If one or more of the column values in the row inserted by the 11558 ** new change differ from those in the row deleted by the existing 11559 ** change, the existing DELETE is replaced by an UPDATE within the 11560 ** changegroup. Otherwise, if the inserted row is exactly the same 11561 ** as the deleted row, the existing DELETE is simply discarded. 11562 ** <tr><td>DELETE <td>UPDATE <td> 11563 ** The new change is ignored. This case does not occur if the new 11564 ** changeset was recorded immediately after the changesets already 11565 ** added to the changegroup. 11566 ** <tr><td>DELETE <td>DELETE <td> 11567 ** The new change is ignored. This case does not occur if the new 11568 ** changeset was recorded immediately after the changesets already 11569 ** added to the changegroup. 11570 ** </table> 11571 ** 11572 ** If the new changeset contains changes to a table that is already present 11573 ** in the changegroup, then the number of columns and the position of the 11574 ** primary key columns for the table must be consistent. If this is not the 11575 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 11576 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 11577 ** returned. Or, if an out-of-memory condition occurs during processing, this 11578 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 11579 ** of the final contents of the changegroup is undefined. 11580 ** 11581 ** If no error occurs, SQLITE_OK is returned. 11582 */ 11583 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 11584 11585 /* 11586 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 11587 ** METHOD: sqlite3_changegroup 11588 ** 11589 ** Obtain a buffer containing a changeset (or patchset) representing the 11590 ** current contents of the changegroup. If the inputs to the changegroup 11591 ** were themselves changesets, the output is a changeset. Or, if the 11592 ** inputs were patchsets, the output is also a patchset. 11593 ** 11594 ** As with the output of the sqlite3session_changeset() and 11595 ** sqlite3session_patchset() functions, all changes related to a single 11596 ** table are grouped together in the output of this function. Tables appear 11597 ** in the same order as for the very first changeset added to the changegroup. 11598 ** If the second or subsequent changesets added to the changegroup contain 11599 ** changes for tables that do not appear in the first changeset, they are 11600 ** appended onto the end of the output changeset, again in the order in 11601 ** which they are first encountered. 11602 ** 11603 ** If an error occurs, an SQLite error code is returned and the output 11604 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 11605 ** is returned and the output variables are set to the size of and a 11606 ** pointer to the output buffer, respectively. In this case it is the 11607 ** responsibility of the caller to eventually free the buffer using a 11608 ** call to sqlite3_free(). 11609 */ 11610 SQLITE_API int sqlite3changegroup_output( 11611 sqlite3_changegroup*, 11612 int *pnData, /* OUT: Size of output buffer in bytes */ 11613 void **ppData /* OUT: Pointer to output buffer */ 11614 ); 11615 11616 /* 11617 ** CAPI3REF: Delete A Changegroup Object 11618 ** DESTRUCTOR: sqlite3_changegroup 11619 */ 11620 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 11621 11622 /* 11623 ** CAPI3REF: Apply A Changeset To A Database 11624 ** 11625 ** Apply a changeset or patchset to a database. These functions attempt to 11626 ** update the "main" database attached to handle db with the changes found in 11627 ** the changeset passed via the second and third arguments. 11628 ** 11629 ** The fourth argument (xFilter) passed to these functions is the "filter 11630 ** callback". If it is not NULL, then for each table affected by at least one 11631 ** change in the changeset, the filter callback is invoked with 11632 ** the table name as the second argument, and a copy of the context pointer 11633 ** passed as the sixth argument as the first. If the "filter callback" 11634 ** returns zero, then no attempt is made to apply any changes to the table. 11635 ** Otherwise, if the return value is non-zero or the xFilter argument to 11636 ** is NULL, all changes related to the table are attempted. 11637 ** 11638 ** For each table that is not excluded by the filter callback, this function 11639 ** tests that the target database contains a compatible table. A table is 11640 ** considered compatible if all of the following are true: 11641 ** 11642 ** <ul> 11643 ** <li> The table has the same name as the name recorded in the 11644 ** changeset, and 11645 ** <li> The table has at least as many columns as recorded in the 11646 ** changeset, and 11647 ** <li> The table has primary key columns in the same position as 11648 ** recorded in the changeset. 11649 ** </ul> 11650 ** 11651 ** If there is no compatible table, it is not an error, but none of the 11652 ** changes associated with the table are applied. A warning message is issued 11653 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 11654 ** one such warning is issued for each table in the changeset. 11655 ** 11656 ** For each change for which there is a compatible table, an attempt is made 11657 ** to modify the table contents according to the UPDATE, INSERT or DELETE 11658 ** change. If a change cannot be applied cleanly, the conflict handler 11659 ** function passed as the fifth argument to sqlite3changeset_apply() may be 11660 ** invoked. A description of exactly when the conflict handler is invoked for 11661 ** each type of change is below. 11662 ** 11663 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 11664 ** of passing anything other than a valid function pointer as the xConflict 11665 ** argument are undefined. 11666 ** 11667 ** Each time the conflict handler function is invoked, it must return one 11668 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 11669 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 11670 ** if the second argument passed to the conflict handler is either 11671 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 11672 ** returns an illegal value, any changes already made are rolled back and 11673 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 11674 ** actions are taken by sqlite3changeset_apply() depending on the value 11675 ** returned by each invocation of the conflict-handler function. Refer to 11676 ** the documentation for the three 11677 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 11678 ** 11679 ** <dl> 11680 ** <dt>DELETE Changes<dd> 11681 ** For each DELETE change, the function checks if the target database 11682 ** contains a row with the same primary key value (or values) as the 11683 ** original row values stored in the changeset. If it does, and the values 11684 ** stored in all non-primary key columns also match the values stored in 11685 ** the changeset the row is deleted from the target database. 11686 ** 11687 ** If a row with matching primary key values is found, but one or more of 11688 ** the non-primary key fields contains a value different from the original 11689 ** row value stored in the changeset, the conflict-handler function is 11690 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 11691 ** database table has more columns than are recorded in the changeset, 11692 ** only the values of those non-primary key fields are compared against 11693 ** the current database contents - any trailing database table columns 11694 ** are ignored. 11695 ** 11696 ** If no row with matching primary key values is found in the database, 11697 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11698 ** passed as the second argument. 11699 ** 11700 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 11701 ** (which can only happen if a foreign key constraint is violated), the 11702 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 11703 ** passed as the second argument. This includes the case where the DELETE 11704 ** operation is attempted because an earlier call to the conflict handler 11705 ** function returned [SQLITE_CHANGESET_REPLACE]. 11706 ** 11707 ** <dt>INSERT Changes<dd> 11708 ** For each INSERT change, an attempt is made to insert the new row into 11709 ** the database. If the changeset row contains fewer fields than the 11710 ** database table, the trailing fields are populated with their default 11711 ** values. 11712 ** 11713 ** If the attempt to insert the row fails because the database already 11714 ** contains a row with the same primary key values, the conflict handler 11715 ** function is invoked with the second argument set to 11716 ** [SQLITE_CHANGESET_CONFLICT]. 11717 ** 11718 ** If the attempt to insert the row fails because of some other constraint 11719 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11720 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11721 ** This includes the case where the INSERT operation is re-attempted because 11722 ** an earlier call to the conflict handler function returned 11723 ** [SQLITE_CHANGESET_REPLACE]. 11724 ** 11725 ** <dt>UPDATE Changes<dd> 11726 ** For each UPDATE change, the function checks if the target database 11727 ** contains a row with the same primary key value (or values) as the 11728 ** original row values stored in the changeset. If it does, and the values 11729 ** stored in all modified non-primary key columns also match the values 11730 ** stored in the changeset the row is updated within the target database. 11731 ** 11732 ** If a row with matching primary key values is found, but one or more of 11733 ** the modified non-primary key fields contains a value different from an 11734 ** original row value stored in the changeset, the conflict-handler function 11735 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11736 ** UPDATE changes only contain values for non-primary key fields that are 11737 ** to be modified, only those fields need to match the original values to 11738 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11739 ** 11740 ** If no row with matching primary key values is found in the database, 11741 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11742 ** passed as the second argument. 11743 ** 11744 ** If the UPDATE operation is attempted, but SQLite returns 11745 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11746 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11747 ** This includes the case where the UPDATE operation is attempted after 11748 ** an earlier call to the conflict handler function returned 11749 ** [SQLITE_CHANGESET_REPLACE]. 11750 ** </dl> 11751 ** 11752 ** It is safe to execute SQL statements, including those that write to the 11753 ** table that the callback related to, from within the xConflict callback. 11754 ** This can be used to further customize the application's conflict 11755 ** resolution strategy. 11756 ** 11757 ** All changes made by these functions are enclosed in a savepoint transaction. 11758 ** If any other error (aside from a constraint failure when attempting to 11759 ** write to the target database) occurs, then the savepoint transaction is 11760 ** rolled back, restoring the target database to its original state, and an 11761 ** SQLite error code returned. 11762 ** 11763 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11764 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11765 ** may set (*ppRebase) to point to a "rebase" that may be used with the 11766 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11767 ** is set to the size of the buffer in bytes. It is the responsibility of the 11768 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 11769 ** is only allocated and populated if one or more conflicts were encountered 11770 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 11771 ** APIs for further details. 11772 ** 11773 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11774 ** may be modified by passing a combination of 11775 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11776 ** 11777 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11778 ** and therefore subject to change. 11779 */ 11780 SQLITE_API int sqlite3changeset_apply( 11781 sqlite3 *db, /* Apply change to "main" db of this handle */ 11782 int nChangeset, /* Size of changeset in bytes */ 11783 void *pChangeset, /* Changeset blob */ 11784 int(*xFilter)( 11785 void *pCtx, /* Copy of sixth arg to _apply() */ 11786 const char *zTab /* Table name */ 11787 ), 11788 int(*xConflict)( 11789 void *pCtx, /* Copy of sixth arg to _apply() */ 11790 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11791 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11792 ), 11793 void *pCtx /* First argument passed to xConflict */ 11794 ); 11795 SQLITE_API int sqlite3changeset_apply_v2( 11796 sqlite3 *db, /* Apply change to "main" db of this handle */ 11797 int nChangeset, /* Size of changeset in bytes */ 11798 void *pChangeset, /* Changeset blob */ 11799 int(*xFilter)( 11800 void *pCtx, /* Copy of sixth arg to _apply() */ 11801 const char *zTab /* Table name */ 11802 ), 11803 int(*xConflict)( 11804 void *pCtx, /* Copy of sixth arg to _apply() */ 11805 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11806 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11807 ), 11808 void *pCtx, /* First argument passed to xConflict */ 11809 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11810 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11811 ); 11812 11813 /* 11814 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 11815 ** 11816 ** The following flags may passed via the 9th parameter to 11817 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11818 ** 11819 ** <dl> 11820 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11821 ** Usually, the sessions module encloses all operations performed by 11822 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11823 ** SAVEPOINT is committed if the changeset or patchset is successfully 11824 ** applied, or rolled back if an error occurs. Specifying this flag 11825 ** causes the sessions module to omit this savepoint. In this case, if the 11826 ** caller has an open transaction or savepoint when apply_v2() is called, 11827 ** it may revert the partially applied changeset by rolling it back. 11828 ** 11829 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11830 ** Invert the changeset before applying it. This is equivalent to inverting 11831 ** a changeset using sqlite3changeset_invert() before applying it. It is 11832 ** an error to specify this flag with a patchset. 11833 */ 11834 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11835 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11836 11837 /* 11838 ** CAPI3REF: Constants Passed To The Conflict Handler 11839 ** 11840 ** Values that may be passed as the second argument to a conflict-handler. 11841 ** 11842 ** <dl> 11843 ** <dt>SQLITE_CHANGESET_DATA<dd> 11844 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 11845 ** when processing a DELETE or UPDATE change if a row with the required 11846 ** PRIMARY KEY fields is present in the database, but one or more other 11847 ** (non primary-key) fields modified by the update do not contain the 11848 ** expected "before" values. 11849 ** 11850 ** The conflicting row, in this case, is the database row with the matching 11851 ** primary key. 11852 ** 11853 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11854 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11855 ** argument when processing a DELETE or UPDATE change if a row with the 11856 ** required PRIMARY KEY fields is not present in the database. 11857 ** 11858 ** There is no conflicting row in this case. The results of invoking the 11859 ** sqlite3changeset_conflict() API are undefined. 11860 ** 11861 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11862 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 11863 ** handler while processing an INSERT change if the operation would result 11864 ** in duplicate primary key values. 11865 ** 11866 ** The conflicting row in this case is the database row with the matching 11867 ** primary key. 11868 ** 11869 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11870 ** If foreign key handling is enabled, and applying a changeset leaves the 11871 ** database in a state containing foreign key violations, the conflict 11872 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11873 ** exactly once before the changeset is committed. If the conflict handler 11874 ** returns CHANGESET_OMIT, the changes, including those that caused the 11875 ** foreign key constraint violation, are committed. Or, if it returns 11876 ** CHANGESET_ABORT, the changeset is rolled back. 11877 ** 11878 ** No current or conflicting row information is provided. The only function 11879 ** it is possible to call on the supplied sqlite3_changeset_iter handle 11880 ** is sqlite3changeset_fk_conflicts(). 11881 ** 11882 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11883 ** If any other constraint violation occurs while applying a change (i.e. 11884 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11885 ** invoked with CHANGESET_CONSTRAINT as the second argument. 11886 ** 11887 ** There is no conflicting row in this case. The results of invoking the 11888 ** sqlite3changeset_conflict() API are undefined. 11889 ** 11890 ** </dl> 11891 */ 11892 #define SQLITE_CHANGESET_DATA 1 11893 #define SQLITE_CHANGESET_NOTFOUND 2 11894 #define SQLITE_CHANGESET_CONFLICT 3 11895 #define SQLITE_CHANGESET_CONSTRAINT 4 11896 #define SQLITE_CHANGESET_FOREIGN_KEY 5 11897 11898 /* 11899 ** CAPI3REF: Constants Returned By The Conflict Handler 11900 ** 11901 ** A conflict handler callback must return one of the following three values. 11902 ** 11903 ** <dl> 11904 ** <dt>SQLITE_CHANGESET_OMIT<dd> 11905 ** If a conflict handler returns this value no special action is taken. The 11906 ** change that caused the conflict is not applied. The session module 11907 ** continues to the next change in the changeset. 11908 ** 11909 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 11910 ** This value may only be returned if the second argument to the conflict 11911 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11912 ** is not the case, any changes applied so far are rolled back and the 11913 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11914 ** 11915 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11916 ** handler, then the conflicting row is either updated or deleted, depending 11917 ** on the type of change. 11918 ** 11919 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11920 ** handler, then the conflicting row is removed from the database and a 11921 ** second attempt to apply the change is made. If this second attempt fails, 11922 ** the original row is restored to the database before continuing. 11923 ** 11924 ** <dt>SQLITE_CHANGESET_ABORT<dd> 11925 ** If this value is returned, any changes applied so far are rolled back 11926 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11927 ** </dl> 11928 */ 11929 #define SQLITE_CHANGESET_OMIT 0 11930 #define SQLITE_CHANGESET_REPLACE 1 11931 #define SQLITE_CHANGESET_ABORT 2 11932 11933 /* 11934 ** CAPI3REF: Rebasing changesets 11935 ** EXPERIMENTAL 11936 ** 11937 ** Suppose there is a site hosting a database in state S0. And that 11938 ** modifications are made that move that database to state S1 and a 11939 ** changeset recorded (the "local" changeset). Then, a changeset based 11940 ** on S0 is received from another site (the "remote" changeset) and 11941 ** applied to the database. The database is then in state 11942 ** (S1+"remote"), where the exact state depends on any conflict 11943 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 11944 ** Rebasing a changeset is to update it to take those conflict 11945 ** resolution decisions into account, so that the same conflicts 11946 ** do not have to be resolved elsewhere in the network. 11947 ** 11948 ** For example, if both the local and remote changesets contain an 11949 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 11950 ** 11951 ** local: INSERT INTO t1 VALUES(1, 'v1'); 11952 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 11953 ** 11954 ** and the conflict resolution is REPLACE, then the INSERT change is 11955 ** removed from the local changeset (it was overridden). Or, if the 11956 ** conflict resolution was "OMIT", then the local changeset is modified 11957 ** to instead contain: 11958 ** 11959 ** UPDATE t1 SET b = 'v2' WHERE a=1; 11960 ** 11961 ** Changes within the local changeset are rebased as follows: 11962 ** 11963 ** <dl> 11964 ** <dt>Local INSERT<dd> 11965 ** This may only conflict with a remote INSERT. If the conflict 11966 ** resolution was OMIT, then add an UPDATE change to the rebased 11967 ** changeset. Or, if the conflict resolution was REPLACE, add 11968 ** nothing to the rebased changeset. 11969 ** 11970 ** <dt>Local DELETE<dd> 11971 ** This may conflict with a remote UPDATE or DELETE. In both cases the 11972 ** only possible resolution is OMIT. If the remote operation was a 11973 ** DELETE, then add no change to the rebased changeset. If the remote 11974 ** operation was an UPDATE, then the old.* fields of change are updated 11975 ** to reflect the new.* values in the UPDATE. 11976 ** 11977 ** <dt>Local UPDATE<dd> 11978 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 11979 ** with a DELETE, and the conflict resolution was OMIT, then the update 11980 ** is changed into an INSERT. Any undefined values in the new.* record 11981 ** from the update change are filled in using the old.* values from 11982 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 11983 ** the UPDATE change is simply omitted from the rebased changeset. 11984 ** 11985 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 11986 ** the old.* values are rebased using the new.* values in the remote 11987 ** change. Or, if the resolution is REPLACE, then the change is copied 11988 ** into the rebased changeset with updates to columns also updated by 11989 ** the conflicting remote UPDATE removed. If this means no columns would 11990 ** be updated, the change is omitted. 11991 ** </dl> 11992 ** 11993 ** A local change may be rebased against multiple remote changes 11994 ** simultaneously. If a single key is modified by multiple remote 11995 ** changesets, they are combined as follows before the local changeset 11996 ** is rebased: 11997 ** 11998 ** <ul> 11999 ** <li> If there has been one or more REPLACE resolutions on a 12000 ** key, it is rebased according to a REPLACE. 12001 ** 12002 ** <li> If there have been no REPLACE resolutions on a key, then 12003 ** the local changeset is rebased according to the most recent 12004 ** of the OMIT resolutions. 12005 ** </ul> 12006 ** 12007 ** Note that conflict resolutions from multiple remote changesets are 12008 ** combined on a per-field basis, not per-row. This means that in the 12009 ** case of multiple remote UPDATE operations, some fields of a single 12010 ** local change may be rebased for REPLACE while others are rebased for 12011 ** OMIT. 12012 ** 12013 ** In order to rebase a local changeset, the remote changeset must first 12014 ** be applied to the local database using sqlite3changeset_apply_v2() and 12015 ** the buffer of rebase information captured. Then: 12016 ** 12017 ** <ol> 12018 ** <li> An sqlite3_rebaser object is created by calling 12019 ** sqlite3rebaser_create(). 12020 ** <li> The new object is configured with the rebase buffer obtained from 12021 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 12022 ** If the local changeset is to be rebased against multiple remote 12023 ** changesets, then sqlite3rebaser_configure() should be called 12024 ** multiple times, in the same order that the multiple 12025 ** sqlite3changeset_apply_v2() calls were made. 12026 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 12027 ** <li> The sqlite3_rebaser object is deleted by calling 12028 ** sqlite3rebaser_delete(). 12029 ** </ol> 12030 */ 12031 typedef struct sqlite3_rebaser sqlite3_rebaser; 12032 12033 /* 12034 ** CAPI3REF: Create a changeset rebaser object. 12035 ** EXPERIMENTAL 12036 ** 12037 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 12038 ** point to the new object and return SQLITE_OK. Otherwise, if an error 12039 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 12040 ** to NULL. 12041 */ 12042 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 12043 12044 /* 12045 ** CAPI3REF: Configure a changeset rebaser object. 12046 ** EXPERIMENTAL 12047 ** 12048 ** Configure the changeset rebaser object to rebase changesets according 12049 ** to the conflict resolutions described by buffer pRebase (size nRebase 12050 ** bytes), which must have been obtained from a previous call to 12051 ** sqlite3changeset_apply_v2(). 12052 */ 12053 SQLITE_API int sqlite3rebaser_configure( 12054 sqlite3_rebaser*, 12055 int nRebase, const void *pRebase 12056 ); 12057 12058 /* 12059 ** CAPI3REF: Rebase a changeset 12060 ** EXPERIMENTAL 12061 ** 12062 ** Argument pIn must point to a buffer containing a changeset nIn bytes 12063 ** in size. This function allocates and populates a buffer with a copy 12064 ** of the changeset rebased according to the configuration of the 12065 ** rebaser object passed as the first argument. If successful, (*ppOut) 12066 ** is set to point to the new buffer containing the rebased changeset and 12067 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12068 ** responsibility of the caller to eventually free the new buffer using 12069 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12070 ** are set to zero and an SQLite error code returned. 12071 */ 12072 SQLITE_API int sqlite3rebaser_rebase( 12073 sqlite3_rebaser*, 12074 int nIn, const void *pIn, 12075 int *pnOut, void **ppOut 12076 ); 12077 12078 /* 12079 ** CAPI3REF: Delete a changeset rebaser object. 12080 ** EXPERIMENTAL 12081 ** 12082 ** Delete the changeset rebaser object and all associated resources. There 12083 ** should be one call to this function for each successful invocation 12084 ** of sqlite3rebaser_create(). 12085 */ 12086 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12087 12088 /* 12089 ** CAPI3REF: Streaming Versions of API functions. 12090 ** 12091 ** The six streaming API xxx_strm() functions serve similar purposes to the 12092 ** corresponding non-streaming API functions: 12093 ** 12094 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12095 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12096 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12097 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12098 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12099 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12100 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12101 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12102 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12103 ** </table> 12104 ** 12105 ** Non-streaming functions that accept changesets (or patchsets) as input 12106 ** require that the entire changeset be stored in a single buffer in memory. 12107 ** Similarly, those that return a changeset or patchset do so by returning 12108 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 12109 ** Normally this is convenient. However, if an application running in a 12110 ** low-memory environment is required to handle very large changesets, the 12111 ** large contiguous memory allocations required can become onerous. 12112 ** 12113 ** In order to avoid this problem, instead of a single large buffer, input 12114 ** is passed to a streaming API functions by way of a callback function that 12115 ** the sessions module invokes to incrementally request input data as it is 12116 ** required. In all cases, a pair of API function parameters such as 12117 ** 12118 ** <pre> 12119 ** int nChangeset, 12120 ** void *pChangeset, 12121 ** </pre> 12122 ** 12123 ** Is replaced by: 12124 ** 12125 ** <pre> 12126 ** int (*xInput)(void *pIn, void *pData, int *pnData), 12127 ** void *pIn, 12128 ** </pre> 12129 ** 12130 ** Each time the xInput callback is invoked by the sessions module, the first 12131 ** argument passed is a copy of the supplied pIn context pointer. The second 12132 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 12133 ** error occurs the xInput method should copy up to (*pnData) bytes of data 12134 ** into the buffer and set (*pnData) to the actual number of bytes copied 12135 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 12136 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 12137 ** error code should be returned. In all cases, if an xInput callback returns 12138 ** an error, all processing is abandoned and the streaming API function 12139 ** returns a copy of the error code to the caller. 12140 ** 12141 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 12142 ** invoked by the sessions module at any point during the lifetime of the 12143 ** iterator. If such an xInput callback returns an error, the iterator enters 12144 ** an error state, whereby all subsequent calls to iterator functions 12145 ** immediately fail with the same error code as returned by xInput. 12146 ** 12147 ** Similarly, streaming API functions that return changesets (or patchsets) 12148 ** return them in chunks by way of a callback function instead of via a 12149 ** pointer to a single large buffer. In this case, a pair of parameters such 12150 ** as: 12151 ** 12152 ** <pre> 12153 ** int *pnChangeset, 12154 ** void **ppChangeset, 12155 ** </pre> 12156 ** 12157 ** Is replaced by: 12158 ** 12159 ** <pre> 12160 ** int (*xOutput)(void *pOut, const void *pData, int nData), 12161 ** void *pOut 12162 ** </pre> 12163 ** 12164 ** The xOutput callback is invoked zero or more times to return data to 12165 ** the application. The first parameter passed to each call is a copy of the 12166 ** pOut pointer supplied by the application. The second parameter, pData, 12167 ** points to a buffer nData bytes in size containing the chunk of output 12168 ** data being returned. If the xOutput callback successfully processes the 12169 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 12170 ** it should return some other SQLite error code. In this case processing 12171 ** is immediately abandoned and the streaming API function returns a copy 12172 ** of the xOutput error code to the application. 12173 ** 12174 ** The sessions module never invokes an xOutput callback with the third 12175 ** parameter set to a value less than or equal to zero. Other than this, 12176 ** no guarantees are made as to the size of the chunks of data returned. 12177 */ 12178 SQLITE_API int sqlite3changeset_apply_strm( 12179 sqlite3 *db, /* Apply change to "main" db of this handle */ 12180 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12181 void *pIn, /* First arg for xInput */ 12182 int(*xFilter)( 12183 void *pCtx, /* Copy of sixth arg to _apply() */ 12184 const char *zTab /* Table name */ 12185 ), 12186 int(*xConflict)( 12187 void *pCtx, /* Copy of sixth arg to _apply() */ 12188 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12189 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12190 ), 12191 void *pCtx /* First argument passed to xConflict */ 12192 ); 12193 SQLITE_API int sqlite3changeset_apply_v2_strm( 12194 sqlite3 *db, /* Apply change to "main" db of this handle */ 12195 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12196 void *pIn, /* First arg for xInput */ 12197 int(*xFilter)( 12198 void *pCtx, /* Copy of sixth arg to _apply() */ 12199 const char *zTab /* Table name */ 12200 ), 12201 int(*xConflict)( 12202 void *pCtx, /* Copy of sixth arg to _apply() */ 12203 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12204 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12205 ), 12206 void *pCtx, /* First argument passed to xConflict */ 12207 void **ppRebase, int *pnRebase, 12208 int flags 12209 ); 12210 SQLITE_API int sqlite3changeset_concat_strm( 12211 int (*xInputA)(void *pIn, void *pData, int *pnData), 12212 void *pInA, 12213 int (*xInputB)(void *pIn, void *pData, int *pnData), 12214 void *pInB, 12215 int (*xOutput)(void *pOut, const void *pData, int nData), 12216 void *pOut 12217 ); 12218 SQLITE_API int sqlite3changeset_invert_strm( 12219 int (*xInput)(void *pIn, void *pData, int *pnData), 12220 void *pIn, 12221 int (*xOutput)(void *pOut, const void *pData, int nData), 12222 void *pOut 12223 ); 12224 SQLITE_API int sqlite3changeset_start_strm( 12225 sqlite3_changeset_iter **pp, 12226 int (*xInput)(void *pIn, void *pData, int *pnData), 12227 void *pIn 12228 ); 12229 SQLITE_API int sqlite3changeset_start_v2_strm( 12230 sqlite3_changeset_iter **pp, 12231 int (*xInput)(void *pIn, void *pData, int *pnData), 12232 void *pIn, 12233 int flags 12234 ); 12235 SQLITE_API int sqlite3session_changeset_strm( 12236 sqlite3_session *pSession, 12237 int (*xOutput)(void *pOut, const void *pData, int nData), 12238 void *pOut 12239 ); 12240 SQLITE_API int sqlite3session_patchset_strm( 12241 sqlite3_session *pSession, 12242 int (*xOutput)(void *pOut, const void *pData, int nData), 12243 void *pOut 12244 ); 12245 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 12246 int (*xInput)(void *pIn, void *pData, int *pnData), 12247 void *pIn 12248 ); 12249 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 12250 int (*xOutput)(void *pOut, const void *pData, int nData), 12251 void *pOut 12252 ); 12253 SQLITE_API int sqlite3rebaser_rebase_strm( 12254 sqlite3_rebaser *pRebaser, 12255 int (*xInput)(void *pIn, void *pData, int *pnData), 12256 void *pIn, 12257 int (*xOutput)(void *pOut, const void *pData, int nData), 12258 void *pOut 12259 ); 12260 12261 /* 12262 ** CAPI3REF: Configure global parameters 12263 ** 12264 ** The sqlite3session_config() interface is used to make global configuration 12265 ** changes to the sessions module in order to tune it to the specific needs 12266 ** of the application. 12267 ** 12268 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 12269 ** while any other thread is inside any other sessions method then the 12270 ** results are undefined. Furthermore, if it is invoked after any sessions 12271 ** related objects have been created, the results are also undefined. 12272 ** 12273 ** The first argument to the sqlite3session_config() function must be one 12274 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 12275 ** interpretation of the (void*) value passed as the second parameter and 12276 ** the effect of calling this function depends on the value of the first 12277 ** parameter. 12278 ** 12279 ** <dl> 12280 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 12281 ** By default, the sessions module streaming interfaces attempt to input 12282 ** and output data in approximately 1 KiB chunks. This operand may be used 12283 ** to set and query the value of this configuration setting. The pointer 12284 ** passed as the second argument must point to a value of type (int). 12285 ** If this value is greater than 0, it is used as the new streaming data 12286 ** chunk size for both input and output. Before returning, the (int) value 12287 ** pointed to by pArg is set to the final value of the streaming interface 12288 ** chunk size. 12289 ** </dl> 12290 ** 12291 ** This function returns SQLITE_OK if successful, or an SQLite error code 12292 ** otherwise. 12293 */ 12294 SQLITE_API int sqlite3session_config(int op, void *pArg); 12295 12296 /* 12297 ** CAPI3REF: Values for sqlite3session_config(). 12298 */ 12299 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 12300 12301 /* 12302 ** Make sure we can call this stuff from C++. 12303 */ 12304 #ifdef __cplusplus 12305 } 12306 #endif 12307 12308 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 12309 12310 /******** End of sqlite3session.h *********/ 12311 /******** Begin file fts5.h *********/ 12312 /* 12313 ** 2014 May 31 12314 ** 12315 ** The author disclaims copyright to this source code. In place of 12316 ** a legal notice, here is a blessing: 12317 ** 12318 ** May you do good and not evil. 12319 ** May you find forgiveness for yourself and forgive others. 12320 ** May you share freely, never taking more than you give. 12321 ** 12322 ****************************************************************************** 12323 ** 12324 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 12325 ** FTS5 may be extended with: 12326 ** 12327 ** * custom tokenizers, and 12328 ** * custom auxiliary functions. 12329 */ 12330 12331 12332 #ifndef _FTS5_H 12333 #define _FTS5_H 12334 12335 12336 #ifdef __cplusplus 12337 extern "C" { 12338 #endif 12339 12340 /************************************************************************* 12341 ** CUSTOM AUXILIARY FUNCTIONS 12342 ** 12343 ** Virtual table implementations may overload SQL functions by implementing 12344 ** the sqlite3_module.xFindFunction() method. 12345 */ 12346 12347 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 12348 typedef struct Fts5Context Fts5Context; 12349 typedef struct Fts5PhraseIter Fts5PhraseIter; 12350 12351 typedef void (*fts5_extension_function)( 12352 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 12353 Fts5Context *pFts, /* First arg to pass to pApi functions */ 12354 sqlite3_context *pCtx, /* Context for returning result/error */ 12355 int nVal, /* Number of values in apVal[] array */ 12356 sqlite3_value **apVal /* Array of trailing arguments */ 12357 ); 12358 12359 struct Fts5PhraseIter { 12360 const unsigned char *a; 12361 const unsigned char *b; 12362 }; 12363 12364 /* 12365 ** EXTENSION API FUNCTIONS 12366 ** 12367 ** xUserData(pFts): 12368 ** Return a copy of the context pointer the extension function was 12369 ** registered with. 12370 ** 12371 ** xColumnTotalSize(pFts, iCol, pnToken): 12372 ** If parameter iCol is less than zero, set output variable *pnToken 12373 ** to the total number of tokens in the FTS5 table. Or, if iCol is 12374 ** non-negative but less than the number of columns in the table, return 12375 ** the total number of tokens in column iCol, considering all rows in 12376 ** the FTS5 table. 12377 ** 12378 ** If parameter iCol is greater than or equal to the number of columns 12379 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12380 ** an OOM condition or IO error), an appropriate SQLite error code is 12381 ** returned. 12382 ** 12383 ** xColumnCount(pFts): 12384 ** Return the number of columns in the table. 12385 ** 12386 ** xColumnSize(pFts, iCol, pnToken): 12387 ** If parameter iCol is less than zero, set output variable *pnToken 12388 ** to the total number of tokens in the current row. Or, if iCol is 12389 ** non-negative but less than the number of columns in the table, set 12390 ** *pnToken to the number of tokens in column iCol of the current row. 12391 ** 12392 ** If parameter iCol is greater than or equal to the number of columns 12393 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12394 ** an OOM condition or IO error), an appropriate SQLite error code is 12395 ** returned. 12396 ** 12397 ** This function may be quite inefficient if used with an FTS5 table 12398 ** created with the "columnsize=0" option. 12399 ** 12400 ** xColumnText: 12401 ** This function attempts to retrieve the text of column iCol of the 12402 ** current document. If successful, (*pz) is set to point to a buffer 12403 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 12404 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 12405 ** if an error occurs, an SQLite error code is returned and the final values 12406 ** of (*pz) and (*pn) are undefined. 12407 ** 12408 ** xPhraseCount: 12409 ** Returns the number of phrases in the current query expression. 12410 ** 12411 ** xPhraseSize: 12412 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 12413 ** are numbered starting from zero. 12414 ** 12415 ** xInstCount: 12416 ** Set *pnInst to the total number of occurrences of all phrases within 12417 ** the query within the current row. Return SQLITE_OK if successful, or 12418 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 12419 ** 12420 ** This API can be quite slow if used with an FTS5 table created with the 12421 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12422 ** with either "detail=none" or "detail=column" and "content=" option 12423 ** (i.e. if it is a contentless table), then this API always returns 0. 12424 ** 12425 ** xInst: 12426 ** Query for the details of phrase match iIdx within the current row. 12427 ** Phrase matches are numbered starting from zero, so the iIdx argument 12428 ** should be greater than or equal to zero and smaller than the value 12429 ** output by xInstCount(). 12430 ** 12431 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 12432 ** to the column in which it occurs and *piOff the token offset of the 12433 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 12434 ** code (i.e. SQLITE_NOMEM) if an error occurs. 12435 ** 12436 ** This API can be quite slow if used with an FTS5 table created with the 12437 ** "detail=none" or "detail=column" option. 12438 ** 12439 ** xRowid: 12440 ** Returns the rowid of the current row. 12441 ** 12442 ** xTokenize: 12443 ** Tokenize text using the tokenizer belonging to the FTS5 table. 12444 ** 12445 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 12446 ** This API function is used to query the FTS table for phrase iPhrase 12447 ** of the current query. Specifically, a query equivalent to: 12448 ** 12449 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 12450 ** 12451 ** with $p set to a phrase equivalent to the phrase iPhrase of the 12452 ** current query is executed. Any column filter that applies to 12453 ** phrase iPhrase of the current query is included in $p. For each 12454 ** row visited, the callback function passed as the fourth argument 12455 ** is invoked. The context and API objects passed to the callback 12456 ** function may be used to access the properties of each matched row. 12457 ** Invoking Api.xUserData() returns a copy of the pointer passed as 12458 ** the third argument to pUserData. 12459 ** 12460 ** If the callback function returns any value other than SQLITE_OK, the 12461 ** query is abandoned and the xQueryPhrase function returns immediately. 12462 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 12463 ** Otherwise, the error code is propagated upwards. 12464 ** 12465 ** If the query runs to completion without incident, SQLITE_OK is returned. 12466 ** Or, if some error occurs before the query completes or is aborted by 12467 ** the callback, an SQLite error code is returned. 12468 ** 12469 ** 12470 ** xSetAuxdata(pFts5, pAux, xDelete) 12471 ** 12472 ** Save the pointer passed as the second argument as the extension function's 12473 ** "auxiliary data". The pointer may then be retrieved by the current or any 12474 ** future invocation of the same fts5 extension function made as part of 12475 ** the same MATCH query using the xGetAuxdata() API. 12476 ** 12477 ** Each extension function is allocated a single auxiliary data slot for 12478 ** each FTS query (MATCH expression). If the extension function is invoked 12479 ** more than once for a single FTS query, then all invocations share a 12480 ** single auxiliary data context. 12481 ** 12482 ** If there is already an auxiliary data pointer when this function is 12483 ** invoked, then it is replaced by the new pointer. If an xDelete callback 12484 ** was specified along with the original pointer, it is invoked at this 12485 ** point. 12486 ** 12487 ** The xDelete callback, if one is specified, is also invoked on the 12488 ** auxiliary data pointer after the FTS5 query has finished. 12489 ** 12490 ** If an error (e.g. an OOM condition) occurs within this function, 12491 ** the auxiliary data is set to NULL and an error code returned. If the 12492 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 12493 ** pointer before returning. 12494 ** 12495 ** 12496 ** xGetAuxdata(pFts5, bClear) 12497 ** 12498 ** Returns the current auxiliary data pointer for the fts5 extension 12499 ** function. See the xSetAuxdata() method for details. 12500 ** 12501 ** If the bClear argument is non-zero, then the auxiliary data is cleared 12502 ** (set to NULL) before this function returns. In this case the xDelete, 12503 ** if any, is not invoked. 12504 ** 12505 ** 12506 ** xRowCount(pFts5, pnRow) 12507 ** 12508 ** This function is used to retrieve the total number of rows in the table. 12509 ** In other words, the same value that would be returned by: 12510 ** 12511 ** SELECT count(*) FROM ftstable; 12512 ** 12513 ** xPhraseFirst() 12514 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 12515 ** method, to iterate through all instances of a single query phrase within 12516 ** the current row. This is the same information as is accessible via the 12517 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 12518 ** to use, this API may be faster under some circumstances. To iterate 12519 ** through instances of phrase iPhrase, use the following code: 12520 ** 12521 ** Fts5PhraseIter iter; 12522 ** int iCol, iOff; 12523 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 12524 ** iCol>=0; 12525 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 12526 ** ){ 12527 ** // An instance of phrase iPhrase at offset iOff of column iCol 12528 ** } 12529 ** 12530 ** The Fts5PhraseIter structure is defined above. Applications should not 12531 ** modify this structure directly - it should only be used as shown above 12532 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 12533 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 12534 ** 12535 ** This API can be quite slow if used with an FTS5 table created with the 12536 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12537 ** with either "detail=none" or "detail=column" and "content=" option 12538 ** (i.e. if it is a contentless table), then this API always iterates 12539 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 12540 ** 12541 ** xPhraseNext() 12542 ** See xPhraseFirst above. 12543 ** 12544 ** xPhraseFirstColumn() 12545 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 12546 ** and xPhraseNext() APIs described above. The difference is that instead 12547 ** of iterating through all instances of a phrase in the current row, these 12548 ** APIs are used to iterate through the set of columns in the current row 12549 ** that contain one or more instances of a specified phrase. For example: 12550 ** 12551 ** Fts5PhraseIter iter; 12552 ** int iCol; 12553 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 12554 ** iCol>=0; 12555 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 12556 ** ){ 12557 ** // Column iCol contains at least one instance of phrase iPhrase 12558 ** } 12559 ** 12560 ** This API can be quite slow if used with an FTS5 table created with the 12561 ** "detail=none" option. If the FTS5 table is created with either 12562 ** "detail=none" "content=" option (i.e. if it is a contentless table), 12563 ** then this API always iterates through an empty set (all calls to 12564 ** xPhraseFirstColumn() set iCol to -1). 12565 ** 12566 ** The information accessed using this API and its companion 12567 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 12568 ** (or xInst/xInstCount). The chief advantage of this API is that it is 12569 ** significantly more efficient than those alternatives when used with 12570 ** "detail=column" tables. 12571 ** 12572 ** xPhraseNextColumn() 12573 ** See xPhraseFirstColumn above. 12574 */ 12575 struct Fts5ExtensionApi { 12576 int iVersion; /* Currently always set to 3 */ 12577 12578 void *(*xUserData)(Fts5Context*); 12579 12580 int (*xColumnCount)(Fts5Context*); 12581 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 12582 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 12583 12584 int (*xTokenize)(Fts5Context*, 12585 const char *pText, int nText, /* Text to tokenize */ 12586 void *pCtx, /* Context passed to xToken() */ 12587 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 12588 ); 12589 12590 int (*xPhraseCount)(Fts5Context*); 12591 int (*xPhraseSize)(Fts5Context*, int iPhrase); 12592 12593 int (*xInstCount)(Fts5Context*, int *pnInst); 12594 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 12595 12596 sqlite3_int64 (*xRowid)(Fts5Context*); 12597 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 12598 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 12599 12600 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 12601 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 12602 ); 12603 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 12604 void *(*xGetAuxdata)(Fts5Context*, int bClear); 12605 12606 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 12607 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 12608 12609 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 12610 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 12611 }; 12612 12613 /* 12614 ** CUSTOM AUXILIARY FUNCTIONS 12615 *************************************************************************/ 12616 12617 /************************************************************************* 12618 ** CUSTOM TOKENIZERS 12619 ** 12620 ** Applications may also register custom tokenizer types. A tokenizer 12621 ** is registered by providing fts5 with a populated instance of the 12622 ** following structure. All structure methods must be defined, setting 12623 ** any member of the fts5_tokenizer struct to NULL leads to undefined 12624 ** behaviour. The structure methods are expected to function as follows: 12625 ** 12626 ** xCreate: 12627 ** This function is used to allocate and initialize a tokenizer instance. 12628 ** A tokenizer instance is required to actually tokenize text. 12629 ** 12630 ** The first argument passed to this function is a copy of the (void*) 12631 ** pointer provided by the application when the fts5_tokenizer object 12632 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 12633 ** The second and third arguments are an array of nul-terminated strings 12634 ** containing the tokenizer arguments, if any, specified following the 12635 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 12636 ** to create the FTS5 table. 12637 ** 12638 ** The final argument is an output variable. If successful, (*ppOut) 12639 ** should be set to point to the new tokenizer handle and SQLITE_OK 12640 ** returned. If an error occurs, some value other than SQLITE_OK should 12641 ** be returned. In this case, fts5 assumes that the final value of *ppOut 12642 ** is undefined. 12643 ** 12644 ** xDelete: 12645 ** This function is invoked to delete a tokenizer handle previously 12646 ** allocated using xCreate(). Fts5 guarantees that this function will 12647 ** be invoked exactly once for each successful call to xCreate(). 12648 ** 12649 ** xTokenize: 12650 ** This function is expected to tokenize the nText byte string indicated 12651 ** by argument pText. pText may or may not be nul-terminated. The first 12652 ** argument passed to this function is a pointer to an Fts5Tokenizer object 12653 ** returned by an earlier call to xCreate(). 12654 ** 12655 ** The second argument indicates the reason that FTS5 is requesting 12656 ** tokenization of the supplied text. This is always one of the following 12657 ** four values: 12658 ** 12659 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 12660 ** or removed from the FTS table. The tokenizer is being invoked to 12661 ** determine the set of tokens to add to (or delete from) the 12662 ** FTS index. 12663 ** 12664 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 12665 ** against the FTS index. The tokenizer is being called to tokenize 12666 ** a bareword or quoted string specified as part of the query. 12667 ** 12668 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 12669 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 12670 ** followed by a "*" character, indicating that the last token 12671 ** returned by the tokenizer will be treated as a token prefix. 12672 ** 12673 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 12674 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 12675 ** function. Or an fts5_api.xColumnSize() request made by the same 12676 ** on a columnsize=0 database. 12677 ** </ul> 12678 ** 12679 ** For each token in the input string, the supplied callback xToken() must 12680 ** be invoked. The first argument to it should be a copy of the pointer 12681 ** passed as the second argument to xTokenize(). The third and fourth 12682 ** arguments are a pointer to a buffer containing the token text, and the 12683 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 12684 ** of the first byte of and first byte immediately following the text from 12685 ** which the token is derived within the input. 12686 ** 12687 ** The second argument passed to the xToken() callback ("tflags") should 12688 ** normally be set to 0. The exception is if the tokenizer supports 12689 ** synonyms. In this case see the discussion below for details. 12690 ** 12691 ** FTS5 assumes the xToken() callback is invoked for each token in the 12692 ** order that they occur within the input text. 12693 ** 12694 ** If an xToken() callback returns any value other than SQLITE_OK, then 12695 ** the tokenization should be abandoned and the xTokenize() method should 12696 ** immediately return a copy of the xToken() return value. Or, if the 12697 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 12698 ** if an error occurs with the xTokenize() implementation itself, it 12699 ** may abandon the tokenization and return any error code other than 12700 ** SQLITE_OK or SQLITE_DONE. 12701 ** 12702 ** SYNONYM SUPPORT 12703 ** 12704 ** Custom tokenizers may also support synonyms. Consider a case in which a 12705 ** user wishes to query for a phrase such as "first place". Using the 12706 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 12707 ** of "first place" within the document set, but not alternative forms 12708 ** such as "1st place". In some applications, it would be better to match 12709 ** all instances of "first place" or "1st place" regardless of which form 12710 ** the user specified in the MATCH query text. 12711 ** 12712 ** There are several ways to approach this in FTS5: 12713 ** 12714 ** <ol><li> By mapping all synonyms to a single token. In this case, using 12715 ** the above example, this means that the tokenizer returns the 12716 ** same token for inputs "first" and "1st". Say that token is in 12717 ** fact "first", so that when the user inserts the document "I won 12718 ** 1st place" entries are added to the index for tokens "i", "won", 12719 ** "first" and "place". If the user then queries for '1st + place', 12720 ** the tokenizer substitutes "first" for "1st" and the query works 12721 ** as expected. 12722 ** 12723 ** <li> By querying the index for all synonyms of each query term 12724 ** separately. In this case, when tokenizing query text, the 12725 ** tokenizer may provide multiple synonyms for a single term 12726 ** within the document. FTS5 then queries the index for each 12727 ** synonym individually. For example, faced with the query: 12728 ** 12729 ** <codeblock> 12730 ** ... MATCH 'first place'</codeblock> 12731 ** 12732 ** the tokenizer offers both "1st" and "first" as synonyms for the 12733 ** first token in the MATCH query and FTS5 effectively runs a query 12734 ** similar to: 12735 ** 12736 ** <codeblock> 12737 ** ... MATCH '(first OR 1st) place'</codeblock> 12738 ** 12739 ** except that, for the purposes of auxiliary functions, the query 12740 ** still appears to contain just two phrases - "(first OR 1st)" 12741 ** being treated as a single phrase. 12742 ** 12743 ** <li> By adding multiple synonyms for a single term to the FTS index. 12744 ** Using this method, when tokenizing document text, the tokenizer 12745 ** provides multiple synonyms for each token. So that when a 12746 ** document such as "I won first place" is tokenized, entries are 12747 ** added to the FTS index for "i", "won", "first", "1st" and 12748 ** "place". 12749 ** 12750 ** This way, even if the tokenizer does not provide synonyms 12751 ** when tokenizing query text (it should not - to do so would be 12752 ** inefficient), it doesn't matter if the user queries for 12753 ** 'first + place' or '1st + place', as there are entries in the 12754 ** FTS index corresponding to both forms of the first token. 12755 ** </ol> 12756 ** 12757 ** Whether it is parsing document or query text, any call to xToken that 12758 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12759 ** is considered to supply a synonym for the previous token. For example, 12760 ** when parsing the document "I won first place", a tokenizer that supports 12761 ** synonyms would call xToken() 5 times, as follows: 12762 ** 12763 ** <codeblock> 12764 ** xToken(pCtx, 0, "i", 1, 0, 1); 12765 ** xToken(pCtx, 0, "won", 3, 2, 5); 12766 ** xToken(pCtx, 0, "first", 5, 6, 11); 12767 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12768 ** xToken(pCtx, 0, "place", 5, 12, 17); 12769 **</codeblock> 12770 ** 12771 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12772 ** xToken() is called. Multiple synonyms may be specified for a single token 12773 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12774 ** There is no limit to the number of synonyms that may be provided for a 12775 ** single token. 12776 ** 12777 ** In many cases, method (1) above is the best approach. It does not add 12778 ** extra data to the FTS index or require FTS5 to query for multiple terms, 12779 ** so it is efficient in terms of disk space and query speed. However, it 12780 ** does not support prefix queries very well. If, as suggested above, the 12781 ** token "first" is substituted for "1st" by the tokenizer, then the query: 12782 ** 12783 ** <codeblock> 12784 ** ... MATCH '1s*'</codeblock> 12785 ** 12786 ** will not match documents that contain the token "1st" (as the tokenizer 12787 ** will probably not map "1s" to any prefix of "first"). 12788 ** 12789 ** For full prefix support, method (3) may be preferred. In this case, 12790 ** because the index contains entries for both "first" and "1st", prefix 12791 ** queries such as 'fi*' or '1s*' will match correctly. However, because 12792 ** extra entries are added to the FTS index, this method uses more space 12793 ** within the database. 12794 ** 12795 ** Method (2) offers a midpoint between (1) and (3). Using this method, 12796 ** a query such as '1s*' will match documents that contain the literal 12797 ** token "1st", but not "first" (assuming the tokenizer is not able to 12798 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 12799 ** will match against "1st" and "first". This method does not require 12800 ** extra disk space, as no extra entries are added to the FTS index. 12801 ** On the other hand, it may require more CPU cycles to run MATCH queries, 12802 ** as separate queries of the FTS index are required for each synonym. 12803 ** 12804 ** When using methods (2) or (3), it is important that the tokenizer only 12805 ** provide synonyms when tokenizing document text (method (2)) or query 12806 ** text (method (3)), not both. Doing so will not cause any errors, but is 12807 ** inefficient. 12808 */ 12809 typedef struct Fts5Tokenizer Fts5Tokenizer; 12810 typedef struct fts5_tokenizer fts5_tokenizer; 12811 struct fts5_tokenizer { 12812 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12813 void (*xDelete)(Fts5Tokenizer*); 12814 int (*xTokenize)(Fts5Tokenizer*, 12815 void *pCtx, 12816 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12817 const char *pText, int nText, 12818 int (*xToken)( 12819 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12820 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12821 const char *pToken, /* Pointer to buffer containing token */ 12822 int nToken, /* Size of token in bytes */ 12823 int iStart, /* Byte offset of token within input text */ 12824 int iEnd /* Byte offset of end of token within input text */ 12825 ) 12826 ); 12827 }; 12828 12829 /* Flags that may be passed as the third argument to xTokenize() */ 12830 #define FTS5_TOKENIZE_QUERY 0x0001 12831 #define FTS5_TOKENIZE_PREFIX 0x0002 12832 #define FTS5_TOKENIZE_DOCUMENT 0x0004 12833 #define FTS5_TOKENIZE_AUX 0x0008 12834 12835 /* Flags that may be passed by the tokenizer implementation back to FTS5 12836 ** as the third argument to the supplied xToken callback. */ 12837 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12838 12839 /* 12840 ** END OF CUSTOM TOKENIZERS 12841 *************************************************************************/ 12842 12843 /************************************************************************* 12844 ** FTS5 EXTENSION REGISTRATION API 12845 */ 12846 typedef struct fts5_api fts5_api; 12847 struct fts5_api { 12848 int iVersion; /* Currently always set to 2 */ 12849 12850 /* Create a new tokenizer */ 12851 int (*xCreateTokenizer)( 12852 fts5_api *pApi, 12853 const char *zName, 12854 void *pContext, 12855 fts5_tokenizer *pTokenizer, 12856 void (*xDestroy)(void*) 12857 ); 12858 12859 /* Find an existing tokenizer */ 12860 int (*xFindTokenizer)( 12861 fts5_api *pApi, 12862 const char *zName, 12863 void **ppContext, 12864 fts5_tokenizer *pTokenizer 12865 ); 12866 12867 /* Create a new auxiliary function */ 12868 int (*xCreateFunction)( 12869 fts5_api *pApi, 12870 const char *zName, 12871 void *pContext, 12872 fts5_extension_function xFunction, 12873 void (*xDestroy)(void*) 12874 ); 12875 }; 12876 12877 /* 12878 ** END OF REGISTRATION API 12879 *************************************************************************/ 12880 12881 #ifdef __cplusplus 12882 } /* end of the 'extern "C"' block */ 12883 #endif 12884 12885 #endif /* _FTS5_H */ 12886 12887 /******** End of fts5.h *********/ 12888