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 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_APICALL 58 # define SQLITE_APICALL 59 #endif 60 #ifndef SQLITE_STDCALL 61 # define SQLITE_STDCALL SQLITE_APICALL 62 #endif 63 #ifndef SQLITE_CALLBACK 64 # define SQLITE_CALLBACK 65 #endif 66 #ifndef SQLITE_SYSAPI 67 # define SQLITE_SYSAPI 68 #endif 69 70 /* 71 ** These no-op macros are used in front of interfaces to mark those 72 ** interfaces as either deprecated or experimental. New applications 73 ** should not use deprecated interfaces - they are supported for backwards 74 ** compatibility only. Application writers should be aware that 75 ** experimental interfaces are subject to change in point releases. 76 ** 77 ** These macros used to resolve to various kinds of compiler magic that 78 ** would generate warning messages when they were used. But that 79 ** compiler magic ended up generating such a flurry of bug reports 80 ** that we have taken it all out and gone back to using simple 81 ** noop macros. 82 */ 83 #define SQLITE_DEPRECATED 84 #define SQLITE_EXPERIMENTAL 85 86 /* 87 ** Ensure these symbols were not defined by some previous header file. 88 */ 89 #ifdef SQLITE_VERSION 90 # undef SQLITE_VERSION 91 #endif 92 #ifdef SQLITE_VERSION_NUMBER 93 # undef SQLITE_VERSION_NUMBER 94 #endif 95 96 /* 97 ** CAPI3REF: Compile-Time Library Version Numbers 98 ** 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100 ** evaluates to a string literal that is the SQLite version in the 101 ** format "X.Y.Z" where X is the major version number (always 3 for 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105 ** numbers used in [SQLITE_VERSION].)^ 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107 ** be larger than the release from which it is derived. Either Y will 108 ** be held constant and Z will be incremented or else Y will be incremented 109 ** and Z will be reset to zero. 110 ** 111 ** Since [version 3.6.18] ([dateof:3.6.18]), 112 ** SQLite source code has been stored in the 113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115 ** a string which identifies a particular check-in of SQLite 116 ** within its configuration management system. ^The SQLITE_SOURCE_ID 117 ** string contains the date and time of the check-in (UTC) and a SHA1 118 ** or SHA3-256 hash of the entire source tree. If the source code has 119 ** been edited in any way since it was last checked in, then the last 120 ** four hexadecimal digits of the hash may be modified. 121 ** 122 ** See also: [sqlite3_libversion()], 123 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124 ** [sqlite_version()] and [sqlite_source_id()]. 125 */ 126 #define SQLITE_VERSION "3.23.1" 127 #define SQLITE_VERSION_NUMBER 3023001 128 #define SQLITE_SOURCE_ID "2018-04-10 17:39:29 4bb2294022060e61de7da5c227a69ccd846ba330e31626ebcd59a94efd148b3b" 129 130 /* 131 ** CAPI3REF: Run-Time Library Version Numbers 132 ** KEYWORDS: sqlite3_version sqlite3_sourceid 133 ** 134 ** These interfaces provide the same information as the [SQLITE_VERSION], 135 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136 ** but are associated with the library instead of the header file. ^(Cautious 137 ** programmers might include assert() statements in their application to 138 ** verify that values returned by these interfaces match the macros in 139 ** the header, and thus ensure that the application is 140 ** compiled with matching library and header files. 141 ** 142 ** <blockquote><pre> 143 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146 ** </pre></blockquote>)^ 147 ** 148 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149 ** macro. ^The sqlite3_libversion() function returns a pointer to the 150 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 151 ** function is provided for use in DLLs since DLL users usually do not have 152 ** direct access to string constants within the DLL. ^The 153 ** sqlite3_libversion_number() function returns an integer equal to 154 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155 ** a pointer to a string constant whose value is the same as the 156 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157 ** using an edited copy of [the amalgamation], then the last four characters 158 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159 ** 160 ** See also: [sqlite_version()] and [sqlite_source_id()]. 161 */ 162 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163 SQLITE_API const char *sqlite3_libversion(void); 164 SQLITE_API const char *sqlite3_sourceid(void); 165 SQLITE_API int sqlite3_libversion_number(void); 166 167 /* 168 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169 ** 170 ** ^The sqlite3_compileoption_used() function returns 0 or 1 171 ** indicating whether the specified option was defined at 172 ** compile time. ^The SQLITE_ prefix may be omitted from the 173 ** option name passed to sqlite3_compileoption_used(). 174 ** 175 ** ^The sqlite3_compileoption_get() function allows iterating 176 ** over the list of options that were defined at compile time by 177 ** returning the N-th compile time option string. ^If N is out of range, 178 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179 ** prefix is omitted from any strings returned by 180 ** sqlite3_compileoption_get(). 181 ** 182 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 183 ** and sqlite3_compileoption_get() may be omitted by specifying the 184 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185 ** 186 ** See also: SQL functions [sqlite_compileoption_used()] and 187 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 188 */ 189 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191 SQLITE_API const char *sqlite3_compileoption_get(int N); 192 #endif 193 194 /* 195 ** CAPI3REF: Test To See If The Library Is Threadsafe 196 ** 197 ** ^The sqlite3_threadsafe() function returns zero if and only if 198 ** SQLite was compiled with mutexing code omitted due to the 199 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 200 ** 201 ** SQLite can be compiled with or without mutexes. When 202 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 203 ** are enabled and SQLite is threadsafe. When the 204 ** [SQLITE_THREADSAFE] macro is 0, 205 ** the mutexes are omitted. Without the mutexes, it is not safe 206 ** to use SQLite concurrently from more than one thread. 207 ** 208 ** Enabling mutexes incurs a measurable performance penalty. 209 ** So if speed is of utmost importance, it makes sense to disable 210 ** the mutexes. But for maximum safety, mutexes should be enabled. 211 ** ^The default behavior is for mutexes to be enabled. 212 ** 213 ** This interface can be used by an application to make sure that the 214 ** version of SQLite that it is linking against was compiled with 215 ** the desired setting of the [SQLITE_THREADSAFE] macro. 216 ** 217 ** This interface only reports on the compile-time mutex setting 218 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 219 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 220 ** can be fully or partially disabled using a call to [sqlite3_config()] 221 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 222 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 223 ** sqlite3_threadsafe() function shows only the compile-time setting of 224 ** thread safety, not any run-time changes to that setting made by 225 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 226 ** is unchanged by calls to sqlite3_config().)^ 227 ** 228 ** See the [threading mode] documentation for additional information. 229 */ 230 SQLITE_API int sqlite3_threadsafe(void); 231 232 /* 233 ** CAPI3REF: Database Connection Handle 234 ** KEYWORDS: {database connection} {database connections} 235 ** 236 ** Each open SQLite database is represented by a pointer to an instance of 237 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 238 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 239 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 240 ** and [sqlite3_close_v2()] are its destructors. There are many other 241 ** interfaces (such as 242 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 243 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 244 ** sqlite3 object. 245 */ 246 typedef struct sqlite3 sqlite3; 247 248 /* 249 ** CAPI3REF: 64-Bit Integer Types 250 ** KEYWORDS: sqlite_int64 sqlite_uint64 251 ** 252 ** Because there is no cross-platform way to specify 64-bit integer types 253 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 254 ** 255 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 256 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 257 ** compatibility only. 258 ** 259 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 260 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 261 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 262 ** between 0 and +18446744073709551615 inclusive. 263 */ 264 #ifdef SQLITE_INT64_TYPE 265 typedef SQLITE_INT64_TYPE sqlite_int64; 266 # ifdef SQLITE_UINT64_TYPE 267 typedef SQLITE_UINT64_TYPE sqlite_uint64; 268 # else 269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 270 # endif 271 #elif defined(_MSC_VER) || defined(__BORLANDC__) 272 typedef __int64 sqlite_int64; 273 typedef unsigned __int64 sqlite_uint64; 274 #else 275 typedef long long int sqlite_int64; 276 typedef unsigned long long int sqlite_uint64; 277 #endif 278 typedef sqlite_int64 sqlite3_int64; 279 typedef sqlite_uint64 sqlite3_uint64; 280 281 /* 282 ** If compiling for a processor that lacks floating point support, 283 ** substitute integer for floating-point. 284 */ 285 #ifdef SQLITE_OMIT_FLOATING_POINT 286 # define double sqlite3_int64 287 #endif 288 289 /* 290 ** CAPI3REF: Closing A Database Connection 291 ** DESTRUCTOR: sqlite3 292 ** 293 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 294 ** for the [sqlite3] object. 295 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 296 ** the [sqlite3] object is successfully destroyed and all associated 297 ** resources are deallocated. 298 ** 299 ** ^If the database connection is associated with unfinalized prepared 300 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 301 ** will leave the database connection open and return [SQLITE_BUSY]. 302 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 303 ** and/or unfinished sqlite3_backups, then the database connection becomes 304 ** an unusable "zombie" which will automatically be deallocated when the 305 ** last prepared statement is finalized or the last sqlite3_backup is 306 ** finished. The sqlite3_close_v2() interface is intended for use with 307 ** host languages that are garbage collected, and where the order in which 308 ** destructors are called is arbitrary. 309 ** 310 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 311 ** [sqlite3_blob_close | close] all [BLOB handles], and 312 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 313 ** with the [sqlite3] object prior to attempting to close the object. ^If 314 ** sqlite3_close_v2() is called on a [database connection] that still has 315 ** outstanding [prepared statements], [BLOB handles], and/or 316 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 317 ** of resources is deferred until all [prepared statements], [BLOB handles], 318 ** and [sqlite3_backup] objects are also destroyed. 319 ** 320 ** ^If an [sqlite3] object is destroyed while a transaction is open, 321 ** the transaction is automatically rolled back. 322 ** 323 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 324 ** must be either a NULL 325 ** pointer or an [sqlite3] object pointer obtained 326 ** from [sqlite3_open()], [sqlite3_open16()], or 327 ** [sqlite3_open_v2()], and not previously closed. 328 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 329 ** argument is a harmless no-op. 330 */ 331 SQLITE_API int sqlite3_close(sqlite3*); 332 SQLITE_API int sqlite3_close_v2(sqlite3*); 333 334 /* 335 ** The type for a callback function. 336 ** This is legacy and deprecated. It is included for historical 337 ** compatibility and is not documented. 338 */ 339 typedef int (*sqlite3_callback)(void*,int,char**, char**); 340 341 /* 342 ** CAPI3REF: One-Step Query Execution Interface 343 ** METHOD: sqlite3 344 ** 345 ** The sqlite3_exec() interface is a convenience wrapper around 346 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 347 ** that allows an application to run multiple statements of SQL 348 ** without having to use a lot of C code. 349 ** 350 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 351 ** semicolon-separate SQL statements passed into its 2nd argument, 352 ** in the context of the [database connection] passed in as its 1st 353 ** argument. ^If the callback function of the 3rd argument to 354 ** sqlite3_exec() is not NULL, then it is invoked for each result row 355 ** coming out of the evaluated SQL statements. ^The 4th argument to 356 ** sqlite3_exec() is relayed through to the 1st argument of each 357 ** callback invocation. ^If the callback pointer to sqlite3_exec() 358 ** is NULL, then no callback is ever invoked and result rows are 359 ** ignored. 360 ** 361 ** ^If an error occurs while evaluating the SQL statements passed into 362 ** sqlite3_exec(), then execution of the current statement stops and 363 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 364 ** is not NULL then any error message is written into memory obtained 365 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 366 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 367 ** on error message strings returned through the 5th parameter of 368 ** sqlite3_exec() after the error message string is no longer needed. 369 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 370 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 371 ** NULL before returning. 372 ** 373 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 374 ** routine returns SQLITE_ABORT without invoking the callback again and 375 ** without running any subsequent SQL statements. 376 ** 377 ** ^The 2nd argument to the sqlite3_exec() callback function is the 378 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 379 ** callback is an array of pointers to strings obtained as if from 380 ** [sqlite3_column_text()], one for each column. ^If an element of a 381 ** result row is NULL then the corresponding string pointer for the 382 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 383 ** sqlite3_exec() callback is an array of pointers to strings where each 384 ** entry represents the name of corresponding result column as obtained 385 ** from [sqlite3_column_name()]. 386 ** 387 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 388 ** to an empty string, or a pointer that contains only whitespace and/or 389 ** SQL comments, then no SQL statements are evaluated and the database 390 ** is not changed. 391 ** 392 ** Restrictions: 393 ** 394 ** <ul> 395 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 396 ** is a valid and open [database connection]. 397 ** <li> The application must not close the [database connection] specified by 398 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 399 ** <li> The application must not modify the SQL statement text passed into 400 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 401 ** </ul> 402 */ 403 SQLITE_API int sqlite3_exec( 404 sqlite3*, /* An open database */ 405 const char *sql, /* SQL to be evaluated */ 406 int (*callback)(void*,int,char**,char**), /* Callback function */ 407 void *, /* 1st argument to callback */ 408 char **errmsg /* Error msg written here */ 409 ); 410 411 /* 412 ** CAPI3REF: Result Codes 413 ** KEYWORDS: {result code definitions} 414 ** 415 ** Many SQLite functions return an integer result code from the set shown 416 ** here in order to indicate success or failure. 417 ** 418 ** New error codes may be added in future versions of SQLite. 419 ** 420 ** See also: [extended result code definitions] 421 */ 422 #define SQLITE_OK 0 /* Successful result */ 423 /* beginning-of-error-codes */ 424 #define SQLITE_ERROR 1 /* Generic error */ 425 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 426 #define SQLITE_PERM 3 /* Access permission denied */ 427 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 428 #define SQLITE_BUSY 5 /* The database file is locked */ 429 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 430 #define SQLITE_NOMEM 7 /* A malloc() failed */ 431 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 432 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 433 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 434 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 435 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 436 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 437 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 438 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 439 #define SQLITE_EMPTY 16 /* Internal use only */ 440 #define SQLITE_SCHEMA 17 /* The database schema changed */ 441 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 442 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 443 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 444 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 445 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 446 #define SQLITE_AUTH 23 /* Authorization denied */ 447 #define SQLITE_FORMAT 24 /* Not used */ 448 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 449 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 450 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 451 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 452 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 453 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 454 /* end-of-error-codes */ 455 456 /* 457 ** CAPI3REF: Extended Result Codes 458 ** KEYWORDS: {extended result code definitions} 459 ** 460 ** In its default configuration, SQLite API routines return one of 30 integer 461 ** [result codes]. However, experience has shown that many of 462 ** these result codes are too coarse-grained. They do not provide as 463 ** much information about problems as programmers might like. In an effort to 464 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 465 ** and later) include 466 ** support for additional result codes that provide more detailed information 467 ** about errors. These [extended result codes] are enabled or disabled 468 ** on a per database connection basis using the 469 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 470 ** the most recent error can be obtained using 471 ** [sqlite3_extended_errcode()]. 472 */ 473 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 474 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 475 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 476 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 477 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 478 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 479 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 480 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 481 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 482 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 483 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 484 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 485 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 486 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 487 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 488 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 489 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 490 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 491 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 492 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 493 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 494 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 495 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 496 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 497 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 498 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 499 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 500 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 501 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 502 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 503 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 504 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 505 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 506 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 507 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 508 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 509 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 510 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 511 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 512 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 513 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 514 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 515 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 516 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 517 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 518 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 519 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 520 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 521 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 522 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 523 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 524 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 525 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 526 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 527 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 528 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 529 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 530 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 531 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 532 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 533 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 534 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 535 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 536 537 /* 538 ** CAPI3REF: Flags For File Open Operations 539 ** 540 ** These bit values are intended for use in the 541 ** 3rd parameter to the [sqlite3_open_v2()] interface and 542 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 543 */ 544 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 545 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 546 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 547 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 548 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 549 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 550 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 551 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 552 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 553 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 554 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 555 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 556 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 557 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 558 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 559 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 560 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 561 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 562 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 563 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 564 565 /* Reserved: 0x00F00000 */ 566 567 /* 568 ** CAPI3REF: Device Characteristics 569 ** 570 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 571 ** object returns an integer which is a vector of these 572 ** bit values expressing I/O characteristics of the mass storage 573 ** device that holds the file that the [sqlite3_io_methods] 574 ** refers to. 575 ** 576 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 577 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 578 ** mean that writes of blocks that are nnn bytes in size and 579 ** are aligned to an address which is an integer multiple of 580 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 581 ** that when data is appended to a file, the data is appended 582 ** first then the size of the file is extended, never the other 583 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 584 ** information is written to disk in the same order as calls 585 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 586 ** after reboot following a crash or power loss, the only bytes in a 587 ** file that were written at the application level might have changed 588 ** and that adjacent bytes, even bytes within the same sector are 589 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 590 ** flag indicates that a file cannot be deleted when open. The 591 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 592 ** read-only media and cannot be changed even by processes with 593 ** elevated privileges. 594 ** 595 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 596 ** filesystem supports doing multiple write operations atomically when those 597 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 598 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 599 */ 600 #define SQLITE_IOCAP_ATOMIC 0x00000001 601 #define SQLITE_IOCAP_ATOMIC512 0x00000002 602 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 603 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 604 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 605 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 606 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 607 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 608 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 609 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 610 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 611 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 612 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 613 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 614 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 615 616 /* 617 ** CAPI3REF: File Locking Levels 618 ** 619 ** SQLite uses one of these integer values as the second 620 ** argument to calls it makes to the xLock() and xUnlock() methods 621 ** of an [sqlite3_io_methods] object. 622 */ 623 #define SQLITE_LOCK_NONE 0 624 #define SQLITE_LOCK_SHARED 1 625 #define SQLITE_LOCK_RESERVED 2 626 #define SQLITE_LOCK_PENDING 3 627 #define SQLITE_LOCK_EXCLUSIVE 4 628 629 /* 630 ** CAPI3REF: Synchronization Type Flags 631 ** 632 ** When SQLite invokes the xSync() method of an 633 ** [sqlite3_io_methods] object it uses a combination of 634 ** these integer values as the second argument. 635 ** 636 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 637 ** sync operation only needs to flush data to mass storage. Inode 638 ** information need not be flushed. If the lower four bits of the flag 639 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 640 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 641 ** to use Mac OS X style fullsync instead of fsync(). 642 ** 643 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 644 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 645 ** settings. The [synchronous pragma] determines when calls to the 646 ** xSync VFS method occur and applies uniformly across all platforms. 647 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 648 ** energetic or rigorous or forceful the sync operations are and 649 ** only make a difference on Mac OSX for the default SQLite code. 650 ** (Third-party VFS implementations might also make the distinction 651 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 652 ** operating systems natively supported by SQLite, only Mac OSX 653 ** cares about the difference.) 654 */ 655 #define SQLITE_SYNC_NORMAL 0x00002 656 #define SQLITE_SYNC_FULL 0x00003 657 #define SQLITE_SYNC_DATAONLY 0x00010 658 659 /* 660 ** CAPI3REF: OS Interface Open File Handle 661 ** 662 ** An [sqlite3_file] object represents an open file in the 663 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 664 ** implementations will 665 ** want to subclass this object by appending additional fields 666 ** for their own use. The pMethods entry is a pointer to an 667 ** [sqlite3_io_methods] object that defines methods for performing 668 ** I/O operations on the open file. 669 */ 670 typedef struct sqlite3_file sqlite3_file; 671 struct sqlite3_file { 672 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 673 }; 674 675 /* 676 ** CAPI3REF: OS Interface File Virtual Methods Object 677 ** 678 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 679 ** [sqlite3_file] object (or, more commonly, a subclass of the 680 ** [sqlite3_file] object) with a pointer to an instance of this object. 681 ** This object defines the methods used to perform various operations 682 ** against the open file represented by the [sqlite3_file] object. 683 ** 684 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 685 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 686 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 687 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 688 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 689 ** to NULL. 690 ** 691 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 692 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 693 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 694 ** flag may be ORed in to indicate that only the data of the file 695 ** and not its inode needs to be synced. 696 ** 697 ** The integer values to xLock() and xUnlock() are one of 698 ** <ul> 699 ** <li> [SQLITE_LOCK_NONE], 700 ** <li> [SQLITE_LOCK_SHARED], 701 ** <li> [SQLITE_LOCK_RESERVED], 702 ** <li> [SQLITE_LOCK_PENDING], or 703 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 704 ** </ul> 705 ** xLock() increases the lock. xUnlock() decreases the lock. 706 ** The xCheckReservedLock() method checks whether any database connection, 707 ** either in this process or in some other process, is holding a RESERVED, 708 ** PENDING, or EXCLUSIVE lock on the file. It returns true 709 ** if such a lock exists and false otherwise. 710 ** 711 ** The xFileControl() method is a generic interface that allows custom 712 ** VFS implementations to directly control an open file using the 713 ** [sqlite3_file_control()] interface. The second "op" argument is an 714 ** integer opcode. The third argument is a generic pointer intended to 715 ** point to a structure that may contain arguments or space in which to 716 ** write return values. Potential uses for xFileControl() might be 717 ** functions to enable blocking locks with timeouts, to change the 718 ** locking strategy (for example to use dot-file locks), to inquire 719 ** about the status of a lock, or to break stale locks. The SQLite 720 ** core reserves all opcodes less than 100 for its own use. 721 ** A [file control opcodes | list of opcodes] less than 100 is available. 722 ** Applications that define a custom xFileControl method should use opcodes 723 ** greater than 100 to avoid conflicts. VFS implementations should 724 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 725 ** recognize. 726 ** 727 ** The xSectorSize() method returns the sector size of the 728 ** device that underlies the file. The sector size is the 729 ** minimum write that can be performed without disturbing 730 ** other bytes in the file. The xDeviceCharacteristics() 731 ** method returns a bit vector describing behaviors of the 732 ** underlying device: 733 ** 734 ** <ul> 735 ** <li> [SQLITE_IOCAP_ATOMIC] 736 ** <li> [SQLITE_IOCAP_ATOMIC512] 737 ** <li> [SQLITE_IOCAP_ATOMIC1K] 738 ** <li> [SQLITE_IOCAP_ATOMIC2K] 739 ** <li> [SQLITE_IOCAP_ATOMIC4K] 740 ** <li> [SQLITE_IOCAP_ATOMIC8K] 741 ** <li> [SQLITE_IOCAP_ATOMIC16K] 742 ** <li> [SQLITE_IOCAP_ATOMIC32K] 743 ** <li> [SQLITE_IOCAP_ATOMIC64K] 744 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 745 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 746 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 747 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 748 ** <li> [SQLITE_IOCAP_IMMUTABLE] 749 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 750 ** </ul> 751 ** 752 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 753 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 754 ** mean that writes of blocks that are nnn bytes in size and 755 ** are aligned to an address which is an integer multiple of 756 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 757 ** that when data is appended to a file, the data is appended 758 ** first then the size of the file is extended, never the other 759 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 760 ** information is written to disk in the same order as calls 761 ** to xWrite(). 762 ** 763 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 764 ** in the unread portions of the buffer with zeros. A VFS that 765 ** fails to zero-fill short reads might seem to work. However, 766 ** failure to zero-fill short reads will eventually lead to 767 ** database corruption. 768 */ 769 typedef struct sqlite3_io_methods sqlite3_io_methods; 770 struct sqlite3_io_methods { 771 int iVersion; 772 int (*xClose)(sqlite3_file*); 773 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 774 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 775 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 776 int (*xSync)(sqlite3_file*, int flags); 777 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 778 int (*xLock)(sqlite3_file*, int); 779 int (*xUnlock)(sqlite3_file*, int); 780 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 781 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 782 int (*xSectorSize)(sqlite3_file*); 783 int (*xDeviceCharacteristics)(sqlite3_file*); 784 /* Methods above are valid for version 1 */ 785 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 786 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 787 void (*xShmBarrier)(sqlite3_file*); 788 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 789 /* Methods above are valid for version 2 */ 790 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 791 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 792 /* Methods above are valid for version 3 */ 793 /* Additional methods may be added in future releases */ 794 }; 795 796 /* 797 ** CAPI3REF: Standard File Control Opcodes 798 ** KEYWORDS: {file control opcodes} {file control opcode} 799 ** 800 ** These integer constants are opcodes for the xFileControl method 801 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 802 ** interface. 803 ** 804 ** <ul> 805 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 806 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 807 ** opcode causes the xFileControl method to write the current state of 808 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 809 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 810 ** into an integer that the pArg argument points to. This capability 811 ** is used during testing and is only available when the SQLITE_TEST 812 ** compile-time option is used. 813 ** 814 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 815 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 816 ** layer a hint of how large the database file will grow to be during the 817 ** current transaction. This hint is not guaranteed to be accurate but it 818 ** is often close. The underlying VFS might choose to preallocate database 819 ** file space based on this hint in order to help writes to the database 820 ** file run faster. 821 ** 822 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 823 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 824 ** extends and truncates the database file in chunks of a size specified 825 ** by the user. The fourth argument to [sqlite3_file_control()] should 826 ** point to an integer (type int) containing the new chunk-size to use 827 ** for the nominated database. Allocating database file space in large 828 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 829 ** improve performance on some systems. 830 ** 831 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 832 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 833 ** to the [sqlite3_file] object associated with a particular database 834 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 835 ** 836 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 837 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 838 ** to the [sqlite3_file] object associated with the journal file (either 839 ** the [rollback journal] or the [write-ahead log]) for a particular database 840 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 841 ** 842 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 843 ** No longer in use. 844 ** 845 ** <li>[[SQLITE_FCNTL_SYNC]] 846 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 847 ** sent to the VFS immediately before the xSync method is invoked on a 848 ** database file descriptor. Or, if the xSync method is not invoked 849 ** because the user has configured SQLite with 850 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 851 ** of the xSync method. In most cases, the pointer argument passed with 852 ** this file-control is NULL. However, if the database file is being synced 853 ** as part of a multi-database commit, the argument points to a nul-terminated 854 ** string containing the transactions master-journal file name. VFSes that 855 ** do not need this signal should silently ignore this opcode. Applications 856 ** should not call [sqlite3_file_control()] with this opcode as doing so may 857 ** disrupt the operation of the specialized VFSes that do require it. 858 ** 859 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 860 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 861 ** and sent to the VFS after a transaction has been committed immediately 862 ** but before the database is unlocked. VFSes that do not need this signal 863 ** should silently ignore this opcode. Applications should not call 864 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 865 ** operation of the specialized VFSes that do require it. 866 ** 867 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 868 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 869 ** retry counts and intervals for certain disk I/O operations for the 870 ** windows [VFS] in order to provide robustness in the presence of 871 ** anti-virus programs. By default, the windows VFS will retry file read, 872 ** file write, and file delete operations up to 10 times, with a delay 873 ** of 25 milliseconds before the first retry and with the delay increasing 874 ** by an additional 25 milliseconds with each subsequent retry. This 875 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 876 ** to be adjusted. The values are changed for all database connections 877 ** within the same process. The argument is a pointer to an array of two 878 ** integers where the first integer is the new retry count and the second 879 ** integer is the delay. If either integer is negative, then the setting 880 ** is not changed but instead the prior value of that setting is written 881 ** into the array entry, allowing the current retry settings to be 882 ** interrogated. The zDbName parameter is ignored. 883 ** 884 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 885 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 886 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 887 ** write ahead log and shared memory files used for transaction control 888 ** are automatically deleted when the latest connection to the database 889 ** closes. Setting persistent WAL mode causes those files to persist after 890 ** close. Persisting the files is useful when other processes that do not 891 ** have write permission on the directory containing the database file want 892 ** to read the database file, as the WAL and shared memory files must exist 893 ** in order for the database to be readable. The fourth parameter to 894 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 895 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 896 ** WAL mode. If the integer is -1, then it is overwritten with the current 897 ** WAL persistence setting. 898 ** 899 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 900 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 901 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 902 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 903 ** xDeviceCharacteristics methods. The fourth parameter to 904 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 905 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 906 ** mode. If the integer is -1, then it is overwritten with the current 907 ** zero-damage mode setting. 908 ** 909 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 910 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 911 ** a write transaction to indicate that, unless it is rolled back for some 912 ** reason, the entire database file will be overwritten by the current 913 ** transaction. This is used by VACUUM operations. 914 ** 915 ** <li>[[SQLITE_FCNTL_VFSNAME]] 916 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 917 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 918 ** final bottom-level VFS are written into memory obtained from 919 ** [sqlite3_malloc()] and the result is stored in the char* variable 920 ** that the fourth parameter of [sqlite3_file_control()] points to. 921 ** The caller is responsible for freeing the memory when done. As with 922 ** all file-control actions, there is no guarantee that this will actually 923 ** do anything. Callers should initialize the char* variable to a NULL 924 ** pointer in case this file-control is not implemented. This file-control 925 ** is intended for diagnostic use only. 926 ** 927 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 928 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 929 ** [VFSes] currently in use. ^(The argument X in 930 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 931 ** of type "[sqlite3_vfs] **". This opcodes will set *X 932 ** to a pointer to the top-level VFS.)^ 933 ** ^When there are multiple VFS shims in the stack, this opcode finds the 934 ** upper-most shim only. 935 ** 936 ** <li>[[SQLITE_FCNTL_PRAGMA]] 937 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 938 ** file control is sent to the open [sqlite3_file] object corresponding 939 ** to the database file to which the pragma statement refers. ^The argument 940 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 941 ** pointers to strings (char**) in which the second element of the array 942 ** is the name of the pragma and the third element is the argument to the 943 ** pragma or NULL if the pragma has no argument. ^The handler for an 944 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 945 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 946 ** or the equivalent and that string will become the result of the pragma or 947 ** the error message if the pragma fails. ^If the 948 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 949 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 950 ** file control returns [SQLITE_OK], then the parser assumes that the 951 ** VFS has handled the PRAGMA itself and the parser generates a no-op 952 ** prepared statement if result string is NULL, or that returns a copy 953 ** of the result string if the string is non-NULL. 954 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 955 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 956 ** that the VFS encountered an error while handling the [PRAGMA] and the 957 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 958 ** file control occurs at the beginning of pragma statement analysis and so 959 ** it is able to override built-in [PRAGMA] statements. 960 ** 961 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 962 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 963 ** file-control may be invoked by SQLite on the database file handle 964 ** shortly after it is opened in order to provide a custom VFS with access 965 ** to the connections busy-handler callback. The argument is of type (void **) 966 ** - an array of two (void *) values. The first (void *) actually points 967 ** to a function of type (int (*)(void *)). In order to invoke the connections 968 ** busy-handler, this function should be invoked with the second (void *) in 969 ** the array as the only argument. If it returns non-zero, then the operation 970 ** should be retried. If it returns zero, the custom VFS should abandon the 971 ** current operation. 972 ** 973 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 974 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 975 ** to have SQLite generate a 976 ** temporary filename using the same algorithm that is followed to generate 977 ** temporary filenames for TEMP tables and other internal uses. The 978 ** argument should be a char** which will be filled with the filename 979 ** written into memory obtained from [sqlite3_malloc()]. The caller should 980 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 981 ** 982 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 983 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 984 ** maximum number of bytes that will be used for memory-mapped I/O. 985 ** The argument is a pointer to a value of type sqlite3_int64 that 986 ** is an advisory maximum number of bytes in the file to memory map. The 987 ** pointer is overwritten with the old value. The limit is not changed if 988 ** the value originally pointed to is negative, and so the current limit 989 ** can be queried by passing in a pointer to a negative number. This 990 ** file-control is used internally to implement [PRAGMA mmap_size]. 991 ** 992 ** <li>[[SQLITE_FCNTL_TRACE]] 993 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 994 ** to the VFS about what the higher layers of the SQLite stack are doing. 995 ** This file control is used by some VFS activity tracing [shims]. 996 ** The argument is a zero-terminated string. Higher layers in the 997 ** SQLite stack may generate instances of this file control if 998 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 999 ** 1000 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1001 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1002 ** pointer to an integer and it writes a boolean into that integer depending 1003 ** on whether or not the file has been renamed, moved, or deleted since it 1004 ** was first opened. 1005 ** 1006 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1007 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1008 ** underlying native file handle associated with a file handle. This file 1009 ** control interprets its argument as a pointer to a native file handle and 1010 ** writes the resulting value there. 1011 ** 1012 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1013 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1014 ** opcode causes the xFileControl method to swap the file handle with the one 1015 ** pointed to by the pArg argument. This capability is used during testing 1016 ** and only needs to be supported when SQLITE_TEST is defined. 1017 ** 1018 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1019 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1020 ** be advantageous to block on the next WAL lock if the lock is not immediately 1021 ** available. The WAL subsystem issues this signal during rare 1022 ** circumstances in order to fix a problem with priority inversion. 1023 ** Applications should <em>not</em> use this file-control. 1024 ** 1025 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1026 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1027 ** VFS should return SQLITE_NOTFOUND for this opcode. 1028 ** 1029 ** <li>[[SQLITE_FCNTL_RBU]] 1030 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1031 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1032 ** this opcode. 1033 ** 1034 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1035 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1036 ** the file descriptor is placed in "batch write mode", which 1037 ** means all subsequent write operations will be deferred and done 1038 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1039 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1040 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1041 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1042 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1043 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1044 ** except for calls to the xWrite method and the xFileControl method 1045 ** with [SQLITE_FCNTL_SIZE_HINT]. 1046 ** 1047 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1048 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1049 ** operations since the previous successful call to 1050 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1051 ** This file control returns [SQLITE_OK] if and only if the writes were 1052 ** all performed successfully and have been committed to persistent storage. 1053 ** ^Regardless of whether or not it is successful, this file control takes 1054 ** the file descriptor out of batch write mode so that all subsequent 1055 ** write operations are independent. 1056 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1057 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1058 ** 1059 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1060 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1061 ** operations since the previous successful call to 1062 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1063 ** ^This file control takes the file descriptor out of batch write mode 1064 ** so that all subsequent write operations are independent. 1065 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1066 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1067 ** 1068 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1069 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1070 ** a file lock using the xLock or xShmLock methods of the VFS to wait 1071 ** for up to M milliseconds before failing, where M is the single 1072 ** unsigned integer parameter. 1073 ** </ul> 1074 */ 1075 #define SQLITE_FCNTL_LOCKSTATE 1 1076 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1077 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1078 #define SQLITE_FCNTL_LAST_ERRNO 4 1079 #define SQLITE_FCNTL_SIZE_HINT 5 1080 #define SQLITE_FCNTL_CHUNK_SIZE 6 1081 #define SQLITE_FCNTL_FILE_POINTER 7 1082 #define SQLITE_FCNTL_SYNC_OMITTED 8 1083 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1084 #define SQLITE_FCNTL_PERSIST_WAL 10 1085 #define SQLITE_FCNTL_OVERWRITE 11 1086 #define SQLITE_FCNTL_VFSNAME 12 1087 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1088 #define SQLITE_FCNTL_PRAGMA 14 1089 #define SQLITE_FCNTL_BUSYHANDLER 15 1090 #define SQLITE_FCNTL_TEMPFILENAME 16 1091 #define SQLITE_FCNTL_MMAP_SIZE 18 1092 #define SQLITE_FCNTL_TRACE 19 1093 #define SQLITE_FCNTL_HAS_MOVED 20 1094 #define SQLITE_FCNTL_SYNC 21 1095 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1096 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1097 #define SQLITE_FCNTL_WAL_BLOCK 24 1098 #define SQLITE_FCNTL_ZIPVFS 25 1099 #define SQLITE_FCNTL_RBU 26 1100 #define SQLITE_FCNTL_VFS_POINTER 27 1101 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1102 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1103 #define SQLITE_FCNTL_PDB 30 1104 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1105 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1106 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1107 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1108 1109 /* deprecated names */ 1110 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1111 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1112 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1113 1114 1115 /* 1116 ** CAPI3REF: Mutex Handle 1117 ** 1118 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1119 ** abstract type for a mutex object. The SQLite core never looks 1120 ** at the internal representation of an [sqlite3_mutex]. It only 1121 ** deals with pointers to the [sqlite3_mutex] object. 1122 ** 1123 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1124 */ 1125 typedef struct sqlite3_mutex sqlite3_mutex; 1126 1127 /* 1128 ** CAPI3REF: Loadable Extension Thunk 1129 ** 1130 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1131 ** the third parameter to entry points of [loadable extensions]. This 1132 ** structure must be typedefed in order to work around compiler warnings 1133 ** on some platforms. 1134 */ 1135 typedef struct sqlite3_api_routines sqlite3_api_routines; 1136 1137 /* 1138 ** CAPI3REF: OS Interface Object 1139 ** 1140 ** An instance of the sqlite3_vfs object defines the interface between 1141 ** the SQLite core and the underlying operating system. The "vfs" 1142 ** in the name of the object stands for "virtual file system". See 1143 ** the [VFS | VFS documentation] for further information. 1144 ** 1145 ** The VFS interface is sometimes extended by adding new methods onto 1146 ** the end. Each time such an extension occurs, the iVersion field 1147 ** is incremented. The iVersion value started out as 1 in 1148 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1149 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1150 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1151 ** may be appended to the sqlite3_vfs object and the iVersion value 1152 ** may increase again in future versions of SQLite. 1153 ** Note that the structure 1154 ** of the sqlite3_vfs object changes in the transition from 1155 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1156 ** and yet the iVersion field was not modified. 1157 ** 1158 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1159 ** structure used by this VFS. mxPathname is the maximum length of 1160 ** a pathname in this VFS. 1161 ** 1162 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1163 ** the pNext pointer. The [sqlite3_vfs_register()] 1164 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1165 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1166 ** searches the list. Neither the application code nor the VFS 1167 ** implementation should use the pNext pointer. 1168 ** 1169 ** The pNext field is the only field in the sqlite3_vfs 1170 ** structure that SQLite will ever modify. SQLite will only access 1171 ** or modify this field while holding a particular static mutex. 1172 ** The application should never modify anything within the sqlite3_vfs 1173 ** object once the object has been registered. 1174 ** 1175 ** The zName field holds the name of the VFS module. The name must 1176 ** be unique across all VFS modules. 1177 ** 1178 ** [[sqlite3_vfs.xOpen]] 1179 ** ^SQLite guarantees that the zFilename parameter to xOpen 1180 ** is either a NULL pointer or string obtained 1181 ** from xFullPathname() with an optional suffix added. 1182 ** ^If a suffix is added to the zFilename parameter, it will 1183 ** consist of a single "-" character followed by no more than 1184 ** 11 alphanumeric and/or "-" characters. 1185 ** ^SQLite further guarantees that 1186 ** the string will be valid and unchanged until xClose() is 1187 ** called. Because of the previous sentence, 1188 ** the [sqlite3_file] can safely store a pointer to the 1189 ** filename if it needs to remember the filename for some reason. 1190 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1191 ** must invent its own temporary name for the file. ^Whenever the 1192 ** xFilename parameter is NULL it will also be the case that the 1193 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1194 ** 1195 ** The flags argument to xOpen() includes all bits set in 1196 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1197 ** or [sqlite3_open16()] is used, then flags includes at least 1198 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1199 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1200 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1201 ** 1202 ** ^(SQLite will also add one of the following flags to the xOpen() 1203 ** call, depending on the object being opened: 1204 ** 1205 ** <ul> 1206 ** <li> [SQLITE_OPEN_MAIN_DB] 1207 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1208 ** <li> [SQLITE_OPEN_TEMP_DB] 1209 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1210 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1211 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1212 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1213 ** <li> [SQLITE_OPEN_WAL] 1214 ** </ul>)^ 1215 ** 1216 ** The file I/O implementation can use the object type flags to 1217 ** change the way it deals with files. For example, an application 1218 ** that does not care about crash recovery or rollback might make 1219 ** the open of a journal file a no-op. Writes to this journal would 1220 ** also be no-ops, and any attempt to read the journal would return 1221 ** SQLITE_IOERR. Or the implementation might recognize that a database 1222 ** file will be doing page-aligned sector reads and writes in a random 1223 ** order and set up its I/O subsystem accordingly. 1224 ** 1225 ** SQLite might also add one of the following flags to the xOpen method: 1226 ** 1227 ** <ul> 1228 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1229 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1230 ** </ul> 1231 ** 1232 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1233 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1234 ** will be set for TEMP databases and their journals, transient 1235 ** databases, and subjournals. 1236 ** 1237 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1238 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1239 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1240 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1241 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1242 ** be created, and that it is an error if it already exists. 1243 ** It is <i>not</i> used to indicate the file should be opened 1244 ** for exclusive access. 1245 ** 1246 ** ^At least szOsFile bytes of memory are allocated by SQLite 1247 ** to hold the [sqlite3_file] structure passed as the third 1248 ** argument to xOpen. The xOpen method does not have to 1249 ** allocate the structure; it should just fill it in. Note that 1250 ** the xOpen method must set the sqlite3_file.pMethods to either 1251 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1252 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1253 ** element will be valid after xOpen returns regardless of the success 1254 ** or failure of the xOpen call. 1255 ** 1256 ** [[sqlite3_vfs.xAccess]] 1257 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1258 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1259 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1260 ** to test whether a file is at least readable. The file can be a 1261 ** directory. 1262 ** 1263 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1264 ** output buffer xFullPathname. The exact size of the output buffer 1265 ** is also passed as a parameter to both methods. If the output buffer 1266 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1267 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1268 ** to prevent this by setting mxPathname to a sufficiently large value. 1269 ** 1270 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1271 ** interfaces are not strictly a part of the filesystem, but they are 1272 ** included in the VFS structure for completeness. 1273 ** The xRandomness() function attempts to return nBytes bytes 1274 ** of good-quality randomness into zOut. The return value is 1275 ** the actual number of bytes of randomness obtained. 1276 ** The xSleep() method causes the calling thread to sleep for at 1277 ** least the number of microseconds given. ^The xCurrentTime() 1278 ** method returns a Julian Day Number for the current date and time as 1279 ** a floating point value. 1280 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1281 ** Day Number multiplied by 86400000 (the number of milliseconds in 1282 ** a 24-hour day). 1283 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1284 ** date and time if that method is available (if iVersion is 2 or 1285 ** greater and the function pointer is not NULL) and will fall back 1286 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1287 ** 1288 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1289 ** are not used by the SQLite core. These optional interfaces are provided 1290 ** by some VFSes to facilitate testing of the VFS code. By overriding 1291 ** system calls with functions under its control, a test program can 1292 ** simulate faults and error conditions that would otherwise be difficult 1293 ** or impossible to induce. The set of system calls that can be overridden 1294 ** varies from one VFS to another, and from one version of the same VFS to the 1295 ** next. Applications that use these interfaces must be prepared for any 1296 ** or all of these interfaces to be NULL or for their behavior to change 1297 ** from one release to the next. Applications must not attempt to access 1298 ** any of these methods if the iVersion of the VFS is less than 3. 1299 */ 1300 typedef struct sqlite3_vfs sqlite3_vfs; 1301 typedef void (*sqlite3_syscall_ptr)(void); 1302 struct sqlite3_vfs { 1303 int iVersion; /* Structure version number (currently 3) */ 1304 int szOsFile; /* Size of subclassed sqlite3_file */ 1305 int mxPathname; /* Maximum file pathname length */ 1306 sqlite3_vfs *pNext; /* Next registered VFS */ 1307 const char *zName; /* Name of this virtual file system */ 1308 void *pAppData; /* Pointer to application-specific data */ 1309 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1310 int flags, int *pOutFlags); 1311 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1312 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1313 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1314 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1315 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1316 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1317 void (*xDlClose)(sqlite3_vfs*, void*); 1318 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1319 int (*xSleep)(sqlite3_vfs*, int microseconds); 1320 int (*xCurrentTime)(sqlite3_vfs*, double*); 1321 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1322 /* 1323 ** The methods above are in version 1 of the sqlite_vfs object 1324 ** definition. Those that follow are added in version 2 or later 1325 */ 1326 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1327 /* 1328 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1329 ** Those below are for version 3 and greater. 1330 */ 1331 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1332 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1333 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1334 /* 1335 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1336 ** New fields may be appended in future versions. The iVersion 1337 ** value will increment whenever this happens. 1338 */ 1339 }; 1340 1341 /* 1342 ** CAPI3REF: Flags for the xAccess VFS method 1343 ** 1344 ** These integer constants can be used as the third parameter to 1345 ** the xAccess method of an [sqlite3_vfs] object. They determine 1346 ** what kind of permissions the xAccess method is looking for. 1347 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1348 ** simply checks whether the file exists. 1349 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1350 ** checks whether the named directory is both readable and writable 1351 ** (in other words, if files can be added, removed, and renamed within 1352 ** the directory). 1353 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1354 ** [temp_store_directory pragma], though this could change in a future 1355 ** release of SQLite. 1356 ** With SQLITE_ACCESS_READ, the xAccess method 1357 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1358 ** currently unused, though it might be used in a future release of 1359 ** SQLite. 1360 */ 1361 #define SQLITE_ACCESS_EXISTS 0 1362 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1363 #define SQLITE_ACCESS_READ 2 /* Unused */ 1364 1365 /* 1366 ** CAPI3REF: Flags for the xShmLock VFS method 1367 ** 1368 ** These integer constants define the various locking operations 1369 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1370 ** following are the only legal combinations of flags to the 1371 ** xShmLock method: 1372 ** 1373 ** <ul> 1374 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1375 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1376 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1377 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1378 ** </ul> 1379 ** 1380 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1381 ** was given on the corresponding lock. 1382 ** 1383 ** The xShmLock method can transition between unlocked and SHARED or 1384 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1385 ** and EXCLUSIVE. 1386 */ 1387 #define SQLITE_SHM_UNLOCK 1 1388 #define SQLITE_SHM_LOCK 2 1389 #define SQLITE_SHM_SHARED 4 1390 #define SQLITE_SHM_EXCLUSIVE 8 1391 1392 /* 1393 ** CAPI3REF: Maximum xShmLock index 1394 ** 1395 ** The xShmLock method on [sqlite3_io_methods] may use values 1396 ** between 0 and this upper bound as its "offset" argument. 1397 ** The SQLite core will never attempt to acquire or release a 1398 ** lock outside of this range 1399 */ 1400 #define SQLITE_SHM_NLOCK 8 1401 1402 1403 /* 1404 ** CAPI3REF: Initialize The SQLite Library 1405 ** 1406 ** ^The sqlite3_initialize() routine initializes the 1407 ** SQLite library. ^The sqlite3_shutdown() routine 1408 ** deallocates any resources that were allocated by sqlite3_initialize(). 1409 ** These routines are designed to aid in process initialization and 1410 ** shutdown on embedded systems. Workstation applications using 1411 ** SQLite normally do not need to invoke either of these routines. 1412 ** 1413 ** A call to sqlite3_initialize() is an "effective" call if it is 1414 ** the first time sqlite3_initialize() is invoked during the lifetime of 1415 ** the process, or if it is the first time sqlite3_initialize() is invoked 1416 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1417 ** of sqlite3_initialize() does any initialization. All other calls 1418 ** are harmless no-ops.)^ 1419 ** 1420 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1421 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1422 ** an effective call to sqlite3_shutdown() does any deinitialization. 1423 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1424 ** 1425 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1426 ** is not. The sqlite3_shutdown() interface must only be called from a 1427 ** single thread. All open [database connections] must be closed and all 1428 ** other SQLite resources must be deallocated prior to invoking 1429 ** sqlite3_shutdown(). 1430 ** 1431 ** Among other things, ^sqlite3_initialize() will invoke 1432 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1433 ** will invoke sqlite3_os_end(). 1434 ** 1435 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1436 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1437 ** the library (perhaps it is unable to allocate a needed resource such 1438 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1439 ** 1440 ** ^The sqlite3_initialize() routine is called internally by many other 1441 ** SQLite interfaces so that an application usually does not need to 1442 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1443 ** calls sqlite3_initialize() so the SQLite library will be automatically 1444 ** initialized when [sqlite3_open()] is called if it has not be initialized 1445 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1446 ** compile-time option, then the automatic calls to sqlite3_initialize() 1447 ** are omitted and the application must call sqlite3_initialize() directly 1448 ** prior to using any other SQLite interface. For maximum portability, 1449 ** it is recommended that applications always invoke sqlite3_initialize() 1450 ** directly prior to using any other SQLite interface. Future releases 1451 ** of SQLite may require this. In other words, the behavior exhibited 1452 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1453 ** default behavior in some future release of SQLite. 1454 ** 1455 ** The sqlite3_os_init() routine does operating-system specific 1456 ** initialization of the SQLite library. The sqlite3_os_end() 1457 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1458 ** performed by these routines include allocation or deallocation 1459 ** of static resources, initialization of global variables, 1460 ** setting up a default [sqlite3_vfs] module, or setting up 1461 ** a default configuration using [sqlite3_config()]. 1462 ** 1463 ** The application should never invoke either sqlite3_os_init() 1464 ** or sqlite3_os_end() directly. The application should only invoke 1465 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1466 ** interface is called automatically by sqlite3_initialize() and 1467 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1468 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1469 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1470 ** When [custom builds | built for other platforms] 1471 ** (using the [SQLITE_OS_OTHER=1] compile-time 1472 ** option) the application must supply a suitable implementation for 1473 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1474 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1475 ** must return [SQLITE_OK] on success and some other [error code] upon 1476 ** failure. 1477 */ 1478 SQLITE_API int sqlite3_initialize(void); 1479 SQLITE_API int sqlite3_shutdown(void); 1480 SQLITE_API int sqlite3_os_init(void); 1481 SQLITE_API int sqlite3_os_end(void); 1482 1483 /* 1484 ** CAPI3REF: Configuring The SQLite Library 1485 ** 1486 ** The sqlite3_config() interface is used to make global configuration 1487 ** changes to SQLite in order to tune SQLite to the specific needs of 1488 ** the application. The default configuration is recommended for most 1489 ** applications and so this routine is usually not necessary. It is 1490 ** provided to support rare applications with unusual needs. 1491 ** 1492 ** <b>The sqlite3_config() interface is not threadsafe. The application 1493 ** must ensure that no other SQLite interfaces are invoked by other 1494 ** threads while sqlite3_config() is running.</b> 1495 ** 1496 ** The sqlite3_config() interface 1497 ** may only be invoked prior to library initialization using 1498 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1499 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1500 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1501 ** Note, however, that ^sqlite3_config() can be called as part of the 1502 ** implementation of an application-defined [sqlite3_os_init()]. 1503 ** 1504 ** The first argument to sqlite3_config() is an integer 1505 ** [configuration option] that determines 1506 ** what property of SQLite is to be configured. Subsequent arguments 1507 ** vary depending on the [configuration option] 1508 ** in the first argument. 1509 ** 1510 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1511 ** ^If the option is unknown or SQLite is unable to set the option 1512 ** then this routine returns a non-zero [error code]. 1513 */ 1514 SQLITE_API int sqlite3_config(int, ...); 1515 1516 /* 1517 ** CAPI3REF: Configure database connections 1518 ** METHOD: sqlite3 1519 ** 1520 ** The sqlite3_db_config() interface is used to make configuration 1521 ** changes to a [database connection]. The interface is similar to 1522 ** [sqlite3_config()] except that the changes apply to a single 1523 ** [database connection] (specified in the first argument). 1524 ** 1525 ** The second argument to sqlite3_db_config(D,V,...) is the 1526 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1527 ** that indicates what aspect of the [database connection] is being configured. 1528 ** Subsequent arguments vary depending on the configuration verb. 1529 ** 1530 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1531 ** the call is considered successful. 1532 */ 1533 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1534 1535 /* 1536 ** CAPI3REF: Memory Allocation Routines 1537 ** 1538 ** An instance of this object defines the interface between SQLite 1539 ** and low-level memory allocation routines. 1540 ** 1541 ** This object is used in only one place in the SQLite interface. 1542 ** A pointer to an instance of this object is the argument to 1543 ** [sqlite3_config()] when the configuration option is 1544 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1545 ** By creating an instance of this object 1546 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1547 ** during configuration, an application can specify an alternative 1548 ** memory allocation subsystem for SQLite to use for all of its 1549 ** dynamic memory needs. 1550 ** 1551 ** Note that SQLite comes with several [built-in memory allocators] 1552 ** that are perfectly adequate for the overwhelming majority of applications 1553 ** and that this object is only useful to a tiny minority of applications 1554 ** with specialized memory allocation requirements. This object is 1555 ** also used during testing of SQLite in order to specify an alternative 1556 ** memory allocator that simulates memory out-of-memory conditions in 1557 ** order to verify that SQLite recovers gracefully from such 1558 ** conditions. 1559 ** 1560 ** The xMalloc, xRealloc, and xFree methods must work like the 1561 ** malloc(), realloc() and free() functions from the standard C library. 1562 ** ^SQLite guarantees that the second argument to 1563 ** xRealloc is always a value returned by a prior call to xRoundup. 1564 ** 1565 ** xSize should return the allocated size of a memory allocation 1566 ** previously obtained from xMalloc or xRealloc. The allocated size 1567 ** is always at least as big as the requested size but may be larger. 1568 ** 1569 ** The xRoundup method returns what would be the allocated size of 1570 ** a memory allocation given a particular requested size. Most memory 1571 ** allocators round up memory allocations at least to the next multiple 1572 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1573 ** Every memory allocation request coming in through [sqlite3_malloc()] 1574 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1575 ** that causes the corresponding memory allocation to fail. 1576 ** 1577 ** The xInit method initializes the memory allocator. For example, 1578 ** it might allocate any require mutexes or initialize internal data 1579 ** structures. The xShutdown method is invoked (indirectly) by 1580 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1581 ** by xInit. The pAppData pointer is used as the only parameter to 1582 ** xInit and xShutdown. 1583 ** 1584 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1585 ** the xInit method, so the xInit method need not be threadsafe. The 1586 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1587 ** not need to be threadsafe either. For all other methods, SQLite 1588 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1589 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1590 ** it is by default) and so the methods are automatically serialized. 1591 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1592 ** methods must be threadsafe or else make their own arrangements for 1593 ** serialization. 1594 ** 1595 ** SQLite will never invoke xInit() more than once without an intervening 1596 ** call to xShutdown(). 1597 */ 1598 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1599 struct sqlite3_mem_methods { 1600 void *(*xMalloc)(int); /* Memory allocation function */ 1601 void (*xFree)(void*); /* Free a prior allocation */ 1602 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1603 int (*xSize)(void*); /* Return the size of an allocation */ 1604 int (*xRoundup)(int); /* Round up request size to allocation size */ 1605 int (*xInit)(void*); /* Initialize the memory allocator */ 1606 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1607 void *pAppData; /* Argument to xInit() and xShutdown() */ 1608 }; 1609 1610 /* 1611 ** CAPI3REF: Configuration Options 1612 ** KEYWORDS: {configuration option} 1613 ** 1614 ** These constants are the available integer configuration options that 1615 ** can be passed as the first argument to the [sqlite3_config()] interface. 1616 ** 1617 ** New configuration options may be added in future releases of SQLite. 1618 ** Existing configuration options might be discontinued. Applications 1619 ** should check the return code from [sqlite3_config()] to make sure that 1620 ** the call worked. The [sqlite3_config()] interface will return a 1621 ** non-zero [error code] if a discontinued or unsupported configuration option 1622 ** is invoked. 1623 ** 1624 ** <dl> 1625 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1626 ** <dd>There are no arguments to this option. ^This option sets the 1627 ** [threading mode] to Single-thread. In other words, it disables 1628 ** all mutexing and puts SQLite into a mode where it can only be used 1629 ** by a single thread. ^If SQLite is compiled with 1630 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1631 ** it is not possible to change the [threading mode] from its default 1632 ** value of Single-thread and so [sqlite3_config()] will return 1633 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1634 ** configuration option.</dd> 1635 ** 1636 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1637 ** <dd>There are no arguments to this option. ^This option sets the 1638 ** [threading mode] to Multi-thread. In other words, it disables 1639 ** mutexing on [database connection] and [prepared statement] objects. 1640 ** The application is responsible for serializing access to 1641 ** [database connections] and [prepared statements]. But other mutexes 1642 ** are enabled so that SQLite will be safe to use in a multi-threaded 1643 ** environment as long as no two threads attempt to use the same 1644 ** [database connection] at the same time. ^If SQLite is compiled with 1645 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1646 ** it is not possible to set the Multi-thread [threading mode] and 1647 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1648 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1649 ** 1650 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1651 ** <dd>There are no arguments to this option. ^This option sets the 1652 ** [threading mode] to Serialized. In other words, this option enables 1653 ** all mutexes including the recursive 1654 ** mutexes on [database connection] and [prepared statement] objects. 1655 ** In this mode (which is the default when SQLite is compiled with 1656 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1657 ** to [database connections] and [prepared statements] so that the 1658 ** application is free to use the same [database connection] or the 1659 ** same [prepared statement] in different threads at the same time. 1660 ** ^If SQLite is compiled with 1661 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1662 ** it is not possible to set the Serialized [threading mode] and 1663 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1664 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1665 ** 1666 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1667 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1668 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1669 ** The argument specifies 1670 ** alternative low-level memory allocation routines to be used in place of 1671 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1672 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1673 ** before the [sqlite3_config()] call returns.</dd> 1674 ** 1675 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1676 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1677 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1678 ** The [sqlite3_mem_methods] 1679 ** structure is filled with the currently defined memory allocation routines.)^ 1680 ** This option can be used to overload the default memory allocation 1681 ** routines with a wrapper that simulations memory allocation failure or 1682 ** tracks memory usage, for example. </dd> 1683 ** 1684 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1685 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1686 ** type int, interpreted as a boolean, which if true provides a hint to 1687 ** SQLite that it should avoid large memory allocations if possible. 1688 ** SQLite will run faster if it is free to make large memory allocations, 1689 ** but some application might prefer to run slower in exchange for 1690 ** guarantees about memory fragmentation that are possible if large 1691 ** allocations are avoided. This hint is normally off. 1692 ** </dd> 1693 ** 1694 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1695 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1696 ** interpreted as a boolean, which enables or disables the collection of 1697 ** memory allocation statistics. ^(When memory allocation statistics are 1698 ** disabled, the following SQLite interfaces become non-operational: 1699 ** <ul> 1700 ** <li> [sqlite3_memory_used()] 1701 ** <li> [sqlite3_memory_highwater()] 1702 ** <li> [sqlite3_soft_heap_limit64()] 1703 ** <li> [sqlite3_status64()] 1704 ** </ul>)^ 1705 ** ^Memory allocation statistics are enabled by default unless SQLite is 1706 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1707 ** allocation statistics are disabled by default. 1708 ** </dd> 1709 ** 1710 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1711 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1712 ** </dd> 1713 ** 1714 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1715 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1716 ** that SQLite can use for the database page cache with the default page 1717 ** cache implementation. 1718 ** This configuration option is a no-op if an application-define page 1719 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1720 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1721 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1722 ** and the number of cache lines (N). 1723 ** The sz argument should be the size of the largest database page 1724 ** (a power of two between 512 and 65536) plus some extra bytes for each 1725 ** page header. ^The number of extra bytes needed by the page header 1726 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1727 ** ^It is harmless, apart from the wasted memory, 1728 ** for the sz parameter to be larger than necessary. The pMem 1729 ** argument must be either a NULL pointer or a pointer to an 8-byte 1730 ** aligned block of memory of at least sz*N bytes, otherwise 1731 ** subsequent behavior is undefined. 1732 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1733 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1734 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1735 ** is exhausted. 1736 ** ^If pMem is NULL and N is non-zero, then each database connection 1737 ** does an initial bulk allocation for page cache memory 1738 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1739 ** of -1024*N bytes if N is negative, . ^If additional 1740 ** page cache memory is needed beyond what is provided by the initial 1741 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1742 ** additional cache line. </dd> 1743 ** 1744 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1745 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1746 ** that SQLite will use for all of its dynamic memory allocation needs 1747 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1748 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1749 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1750 ** [SQLITE_ERROR] if invoked otherwise. 1751 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1752 ** An 8-byte aligned pointer to the memory, 1753 ** the number of bytes in the memory buffer, and the minimum allocation size. 1754 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1755 ** to using its default memory allocator (the system malloc() implementation), 1756 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1757 ** memory pointer is not NULL then the alternative memory 1758 ** allocator is engaged to handle all of SQLites memory allocation needs. 1759 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1760 ** boundary or subsequent behavior of SQLite will be undefined. 1761 ** The minimum allocation size is capped at 2**12. Reasonable values 1762 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1763 ** 1764 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1765 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1766 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1767 ** The argument specifies alternative low-level mutex routines to be used 1768 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1769 ** the content of the [sqlite3_mutex_methods] structure before the call to 1770 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1771 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1772 ** the entire mutexing subsystem is omitted from the build and hence calls to 1773 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1774 ** return [SQLITE_ERROR].</dd> 1775 ** 1776 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1777 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1778 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1779 ** [sqlite3_mutex_methods] 1780 ** structure is filled with the currently defined mutex routines.)^ 1781 ** This option can be used to overload the default mutex allocation 1782 ** routines with a wrapper used to track mutex usage for performance 1783 ** profiling or testing, for example. ^If SQLite is compiled with 1784 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1785 ** the entire mutexing subsystem is omitted from the build and hence calls to 1786 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1787 ** return [SQLITE_ERROR].</dd> 1788 ** 1789 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1790 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1791 ** the default size of lookaside memory on each [database connection]. 1792 ** The first argument is the 1793 ** size of each lookaside buffer slot and the second is the number of 1794 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1795 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1796 ** option to [sqlite3_db_config()] can be used to change the lookaside 1797 ** configuration on individual connections.)^ </dd> 1798 ** 1799 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1800 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1801 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1802 ** the interface to a custom page cache implementation.)^ 1803 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1804 ** 1805 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1806 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1807 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1808 ** the current page cache implementation into that object.)^ </dd> 1809 ** 1810 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1811 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1812 ** global [error log]. 1813 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1814 ** function with a call signature of void(*)(void*,int,const char*), 1815 ** and a pointer to void. ^If the function pointer is not NULL, it is 1816 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1817 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1818 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1819 ** passed through as the first parameter to the application-defined logger 1820 ** function whenever that function is invoked. ^The second parameter to 1821 ** the logger function is a copy of the first parameter to the corresponding 1822 ** [sqlite3_log()] call and is intended to be a [result code] or an 1823 ** [extended result code]. ^The third parameter passed to the logger is 1824 ** log message after formatting via [sqlite3_snprintf()]. 1825 ** The SQLite logging interface is not reentrant; the logger function 1826 ** supplied by the application must not invoke any SQLite interface. 1827 ** In a multi-threaded application, the application-defined logger 1828 ** function must be threadsafe. </dd> 1829 ** 1830 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1831 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1832 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1833 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1834 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1835 ** [sqlite3_open16()] or 1836 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1837 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1838 ** connection is opened. ^If it is globally disabled, filenames are 1839 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1840 ** database connection is opened. ^(By default, URI handling is globally 1841 ** disabled. The default value may be changed by compiling with the 1842 ** [SQLITE_USE_URI] symbol defined.)^ 1843 ** 1844 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1845 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1846 ** argument which is interpreted as a boolean in order to enable or disable 1847 ** the use of covering indices for full table scans in the query optimizer. 1848 ** ^The default setting is determined 1849 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1850 ** if that compile-time option is omitted. 1851 ** The ability to disable the use of covering indices for full table scans 1852 ** is because some incorrectly coded legacy applications might malfunction 1853 ** when the optimization is enabled. Providing the ability to 1854 ** disable the optimization allows the older, buggy application code to work 1855 ** without change even with newer versions of SQLite. 1856 ** 1857 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1858 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1859 ** <dd> These options are obsolete and should not be used by new code. 1860 ** They are retained for backwards compatibility but are now no-ops. 1861 ** </dd> 1862 ** 1863 ** [[SQLITE_CONFIG_SQLLOG]] 1864 ** <dt>SQLITE_CONFIG_SQLLOG 1865 ** <dd>This option is only available if sqlite is compiled with the 1866 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1867 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1868 ** The second should be of type (void*). The callback is invoked by the library 1869 ** in three separate circumstances, identified by the value passed as the 1870 ** fourth parameter. If the fourth parameter is 0, then the database connection 1871 ** passed as the second argument has just been opened. The third argument 1872 ** points to a buffer containing the name of the main database file. If the 1873 ** fourth parameter is 1, then the SQL statement that the third parameter 1874 ** points to has just been executed. Or, if the fourth parameter is 2, then 1875 ** the connection being passed as the second parameter is being closed. The 1876 ** third parameter is passed NULL In this case. An example of using this 1877 ** configuration option can be seen in the "test_sqllog.c" source file in 1878 ** the canonical SQLite source tree.</dd> 1879 ** 1880 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1881 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1882 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1883 ** that are the default mmap size limit (the default setting for 1884 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1885 ** ^The default setting can be overridden by each database connection using 1886 ** either the [PRAGMA mmap_size] command, or by using the 1887 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1888 ** will be silently truncated if necessary so that it does not exceed the 1889 ** compile-time maximum mmap size set by the 1890 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1891 ** ^If either argument to this option is negative, then that argument is 1892 ** changed to its compile-time default. 1893 ** 1894 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1895 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1896 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1897 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1898 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1899 ** that specifies the maximum size of the created heap. 1900 ** 1901 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1902 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1903 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1904 ** is a pointer to an integer and writes into that integer the number of extra 1905 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1906 ** The amount of extra space required can change depending on the compiler, 1907 ** target platform, and SQLite version. 1908 ** 1909 ** [[SQLITE_CONFIG_PMASZ]] 1910 ** <dt>SQLITE_CONFIG_PMASZ 1911 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1912 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1913 ** sorter to that integer. The default minimum PMA Size is set by the 1914 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1915 ** to help with sort operations when multithreaded sorting 1916 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1917 ** to be sorted exceeds the page size times the minimum of the 1918 ** [PRAGMA cache_size] setting and this value. 1919 ** 1920 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1921 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1922 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1923 ** becomes the [statement journal] spill-to-disk threshold. 1924 ** [Statement journals] are held in memory until their size (in bytes) 1925 ** exceeds this threshold, at which point they are written to disk. 1926 ** Or if the threshold is -1, statement journals are always held 1927 ** exclusively in memory. 1928 ** Since many statement journals never become large, setting the spill 1929 ** threshold to a value such as 64KiB can greatly reduce the amount of 1930 ** I/O required to support statement rollback. 1931 ** The default value for this setting is controlled by the 1932 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1933 ** </dl> 1934 */ 1935 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1936 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1937 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1938 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1939 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1940 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 1941 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1942 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1943 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1944 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1945 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1946 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1947 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1948 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1949 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1950 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1951 #define SQLITE_CONFIG_URI 17 /* int */ 1952 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1953 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1954 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1955 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1956 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1957 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1958 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1959 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1960 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1961 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 1962 1963 /* 1964 ** CAPI3REF: Database Connection Configuration Options 1965 ** 1966 ** These constants are the available integer configuration options that 1967 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1968 ** 1969 ** New configuration options may be added in future releases of SQLite. 1970 ** Existing configuration options might be discontinued. Applications 1971 ** should check the return code from [sqlite3_db_config()] to make sure that 1972 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1973 ** non-zero [error code] if a discontinued or unsupported configuration option 1974 ** is invoked. 1975 ** 1976 ** <dl> 1977 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1978 ** <dd> ^This option takes three additional arguments that determine the 1979 ** [lookaside memory allocator] configuration for the [database connection]. 1980 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1981 ** pointer to a memory buffer to use for lookaside memory. 1982 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1983 ** may be NULL in which case SQLite will allocate the 1984 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1985 ** size of each lookaside buffer slot. ^The third argument is the number of 1986 ** slots. The size of the buffer in the first argument must be greater than 1987 ** or equal to the product of the second and third arguments. The buffer 1988 ** must be aligned to an 8-byte boundary. ^If the second argument to 1989 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1990 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1991 ** configuration for a database connection can only be changed when that 1992 ** connection is not currently using lookaside memory, or in other words 1993 ** when the "current value" returned by 1994 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1995 ** Any attempt to change the lookaside memory configuration when lookaside 1996 ** memory is in use leaves the configuration unchanged and returns 1997 ** [SQLITE_BUSY].)^</dd> 1998 ** 1999 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2000 ** <dd> ^This option is used to enable or disable the enforcement of 2001 ** [foreign key constraints]. There should be two additional arguments. 2002 ** The first argument is an integer which is 0 to disable FK enforcement, 2003 ** positive to enable FK enforcement or negative to leave FK enforcement 2004 ** unchanged. The second parameter is a pointer to an integer into which 2005 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2006 ** following this call. The second parameter may be a NULL pointer, in 2007 ** which case the FK enforcement setting is not reported back. </dd> 2008 ** 2009 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2010 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2011 ** There should be two additional arguments. 2012 ** The first argument is an integer which is 0 to disable triggers, 2013 ** positive to enable triggers or negative to leave the setting unchanged. 2014 ** The second parameter is a pointer to an integer into which 2015 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2016 ** following this call. The second parameter may be a NULL pointer, in 2017 ** which case the trigger setting is not reported back. </dd> 2018 ** 2019 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2020 ** <dd> ^This option is used to enable or disable the two-argument 2021 ** version of the [fts3_tokenizer()] function which is part of the 2022 ** [FTS3] full-text search engine extension. 2023 ** There should be two additional arguments. 2024 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2025 ** positive to enable fts3_tokenizer() or negative to leave the setting 2026 ** unchanged. 2027 ** The second parameter is a pointer to an integer into which 2028 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2029 ** following this call. The second parameter may be a NULL pointer, in 2030 ** which case the new setting is not reported back. </dd> 2031 ** 2032 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2033 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2034 ** interface independently of the [load_extension()] SQL function. 2035 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2036 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2037 ** There should be two additional arguments. 2038 ** When the first argument to this interface is 1, then only the C-API is 2039 ** enabled and the SQL function remains disabled. If the first argument to 2040 ** this interface is 0, then both the C-API and the SQL function are disabled. 2041 ** If the first argument is -1, then no changes are made to state of either the 2042 ** C-API or the SQL function. 2043 ** The second parameter is a pointer to an integer into which 2044 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2045 ** is disabled or enabled following this call. The second parameter may 2046 ** be a NULL pointer, in which case the new setting is not reported back. 2047 ** </dd> 2048 ** 2049 ** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2050 ** <dd> ^This option is used to change the name of the "main" database 2051 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2052 ** which will become the new schema name in place of "main". ^SQLite 2053 ** does not make a copy of the new main schema name string, so the application 2054 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2055 ** until after the database connection closes. 2056 ** </dd> 2057 ** 2058 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2059 ** <dd> Usually, when a database in wal mode is closed or detached from a 2060 ** database handle, SQLite checks if this will mean that there are now no 2061 ** connections at all to the database. If so, it performs a checkpoint 2062 ** operation before closing the connection. This option may be used to 2063 ** override this behaviour. The first parameter passed to this operation 2064 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2065 ** default) to enable them, and negative to leave the setting unchanged. 2066 ** The second parameter is a pointer to an integer 2067 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2068 ** have been disabled - 0 if they are not disabled, 1 if they are. 2069 ** </dd> 2070 ** 2071 ** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2072 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2073 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2074 ** a single SQL query statement will always use the same algorithm regardless 2075 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2076 ** that look at the values of bound parameters, which can make some queries 2077 ** slower. But the QPSG has the advantage of more predictable behavior. With 2078 ** the QPSG active, SQLite will always use the same query plan in the field as 2079 ** was used during testing in the lab. 2080 ** The first argument to this setting is an integer which is 0 to disable 2081 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2082 ** unchanged. The second parameter is a pointer to an integer into which 2083 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2084 ** following this call. 2085 ** </dd> 2086 ** 2087 ** <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2088 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2089 ** include output for any operations performed by trigger programs. This 2090 ** option is used to set or clear (the default) a flag that governs this 2091 ** behavior. The first parameter passed to this operation is an integer - 2092 ** positive to enable output for trigger programs, or zero to disable it, 2093 ** or negative to leave the setting unchanged. 2094 ** The second parameter is a pointer to an integer into which is written 2095 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2096 ** it is not disabled, 1 if it is. 2097 ** </dd> 2098 ** </dl> 2099 */ 2100 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2101 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2102 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2103 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2104 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2105 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2106 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2107 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2108 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2109 #define SQLITE_DBCONFIG_MAX 1008 /* Largest DBCONFIG */ 2110 2111 /* 2112 ** CAPI3REF: Enable Or Disable Extended Result Codes 2113 ** METHOD: sqlite3 2114 ** 2115 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2116 ** [extended result codes] feature of SQLite. ^The extended result 2117 ** codes are disabled by default for historical compatibility. 2118 */ 2119 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2120 2121 /* 2122 ** CAPI3REF: Last Insert Rowid 2123 ** METHOD: sqlite3 2124 ** 2125 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2126 ** has a unique 64-bit signed 2127 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2128 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2129 ** names are not also used by explicitly declared columns. ^If 2130 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2131 ** is another alias for the rowid. 2132 ** 2133 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2134 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2135 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2136 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2137 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2138 ** zero. 2139 ** 2140 ** As well as being set automatically as rows are inserted into database 2141 ** tables, the value returned by this function may be set explicitly by 2142 ** [sqlite3_set_last_insert_rowid()] 2143 ** 2144 ** Some virtual table implementations may INSERT rows into rowid tables as 2145 ** part of committing a transaction (e.g. to flush data accumulated in memory 2146 ** to disk). In this case subsequent calls to this function return the rowid 2147 ** associated with these internal INSERT operations, which leads to 2148 ** unintuitive results. Virtual table implementations that do write to rowid 2149 ** tables in this way can avoid this problem by restoring the original 2150 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2151 ** control to the user. 2152 ** 2153 ** ^(If an [INSERT] occurs within a trigger then this routine will 2154 ** return the [rowid] of the inserted row as long as the trigger is 2155 ** running. Once the trigger program ends, the value returned 2156 ** by this routine reverts to what it was before the trigger was fired.)^ 2157 ** 2158 ** ^An [INSERT] that fails due to a constraint violation is not a 2159 ** successful [INSERT] and does not change the value returned by this 2160 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2161 ** and INSERT OR ABORT make no changes to the return value of this 2162 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2163 ** encounters a constraint violation, it does not fail. The 2164 ** INSERT continues to completion after deleting rows that caused 2165 ** the constraint problem so INSERT OR REPLACE will always change 2166 ** the return value of this interface.)^ 2167 ** 2168 ** ^For the purposes of this routine, an [INSERT] is considered to 2169 ** be successful even if it is subsequently rolled back. 2170 ** 2171 ** This function is accessible to SQL statements via the 2172 ** [last_insert_rowid() SQL function]. 2173 ** 2174 ** If a separate thread performs a new [INSERT] on the same 2175 ** database connection while the [sqlite3_last_insert_rowid()] 2176 ** function is running and thus changes the last insert [rowid], 2177 ** then the value returned by [sqlite3_last_insert_rowid()] is 2178 ** unpredictable and might not equal either the old or the new 2179 ** last insert [rowid]. 2180 */ 2181 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2182 2183 /* 2184 ** CAPI3REF: Set the Last Insert Rowid value. 2185 ** METHOD: sqlite3 2186 ** 2187 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2188 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2189 ** without inserting a row into the database. 2190 */ 2191 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2192 2193 /* 2194 ** CAPI3REF: Count The Number Of Rows Modified 2195 ** METHOD: sqlite3 2196 ** 2197 ** ^This function returns the number of rows modified, inserted or 2198 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2199 ** statement on the database connection specified by the only parameter. 2200 ** ^Executing any other type of SQL statement does not modify the value 2201 ** returned by this function. 2202 ** 2203 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2204 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2205 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2206 ** 2207 ** Changes to a view that are intercepted by 2208 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2209 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2210 ** DELETE statement run on a view is always zero. Only changes made to real 2211 ** tables are counted. 2212 ** 2213 ** Things are more complicated if the sqlite3_changes() function is 2214 ** executed while a trigger program is running. This may happen if the 2215 ** program uses the [changes() SQL function], or if some other callback 2216 ** function invokes sqlite3_changes() directly. Essentially: 2217 ** 2218 ** <ul> 2219 ** <li> ^(Before entering a trigger program the value returned by 2220 ** sqlite3_changes() function is saved. After the trigger program 2221 ** has finished, the original value is restored.)^ 2222 ** 2223 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2224 ** statement sets the value returned by sqlite3_changes() 2225 ** upon completion as normal. Of course, this value will not include 2226 ** any changes performed by sub-triggers, as the sqlite3_changes() 2227 ** value will be saved and restored after each sub-trigger has run.)^ 2228 ** </ul> 2229 ** 2230 ** ^This means that if the changes() SQL function (or similar) is used 2231 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2232 ** returns the value as set when the calling statement began executing. 2233 ** ^If it is used by the second or subsequent such statement within a trigger 2234 ** program, the value returned reflects the number of rows modified by the 2235 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2236 ** 2237 ** See also the [sqlite3_total_changes()] interface, the 2238 ** [count_changes pragma], and the [changes() SQL function]. 2239 ** 2240 ** If a separate thread makes changes on the same database connection 2241 ** while [sqlite3_changes()] is running then the value returned 2242 ** is unpredictable and not meaningful. 2243 */ 2244 SQLITE_API int sqlite3_changes(sqlite3*); 2245 2246 /* 2247 ** CAPI3REF: Total Number Of Rows Modified 2248 ** METHOD: sqlite3 2249 ** 2250 ** ^This function returns the total number of rows inserted, modified or 2251 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2252 ** since the database connection was opened, including those executed as 2253 ** part of trigger programs. ^Executing any other type of SQL statement 2254 ** does not affect the value returned by sqlite3_total_changes(). 2255 ** 2256 ** ^Changes made as part of [foreign key actions] are included in the 2257 ** count, but those made as part of REPLACE constraint resolution are 2258 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2259 ** are not counted. 2260 ** 2261 ** See also the [sqlite3_changes()] interface, the 2262 ** [count_changes pragma], and the [total_changes() SQL function]. 2263 ** 2264 ** If a separate thread makes changes on the same database connection 2265 ** while [sqlite3_total_changes()] is running then the value 2266 ** returned is unpredictable and not meaningful. 2267 */ 2268 SQLITE_API int sqlite3_total_changes(sqlite3*); 2269 2270 /* 2271 ** CAPI3REF: Interrupt A Long-Running Query 2272 ** METHOD: sqlite3 2273 ** 2274 ** ^This function causes any pending database operation to abort and 2275 ** return at its earliest opportunity. This routine is typically 2276 ** called in response to a user action such as pressing "Cancel" 2277 ** or Ctrl-C where the user wants a long query operation to halt 2278 ** immediately. 2279 ** 2280 ** ^It is safe to call this routine from a thread different from the 2281 ** thread that is currently running the database operation. But it 2282 ** is not safe to call this routine with a [database connection] that 2283 ** is closed or might close before sqlite3_interrupt() returns. 2284 ** 2285 ** ^If an SQL operation is very nearly finished at the time when 2286 ** sqlite3_interrupt() is called, then it might not have an opportunity 2287 ** to be interrupted and might continue to completion. 2288 ** 2289 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2290 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2291 ** that is inside an explicit transaction, then the entire transaction 2292 ** will be rolled back automatically. 2293 ** 2294 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2295 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2296 ** that are started after the sqlite3_interrupt() call and before the 2297 ** running statements reaches zero are interrupted as if they had been 2298 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2299 ** that are started after the running statement count reaches zero are 2300 ** not effected by the sqlite3_interrupt(). 2301 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2302 ** SQL statements is a no-op and has no effect on SQL statements 2303 ** that are started after the sqlite3_interrupt() call returns. 2304 */ 2305 SQLITE_API void sqlite3_interrupt(sqlite3*); 2306 2307 /* 2308 ** CAPI3REF: Determine If An SQL Statement Is Complete 2309 ** 2310 ** These routines are useful during command-line input to determine if the 2311 ** currently entered text seems to form a complete SQL statement or 2312 ** if additional input is needed before sending the text into 2313 ** SQLite for parsing. ^These routines return 1 if the input string 2314 ** appears to be a complete SQL statement. ^A statement is judged to be 2315 ** complete if it ends with a semicolon token and is not a prefix of a 2316 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2317 ** string literals or quoted identifier names or comments are not 2318 ** independent tokens (they are part of the token in which they are 2319 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2320 ** and comments that follow the final semicolon are ignored. 2321 ** 2322 ** ^These routines return 0 if the statement is incomplete. ^If a 2323 ** memory allocation fails, then SQLITE_NOMEM is returned. 2324 ** 2325 ** ^These routines do not parse the SQL statements thus 2326 ** will not detect syntactically incorrect SQL. 2327 ** 2328 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2329 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2330 ** automatically by sqlite3_complete16(). If that initialization fails, 2331 ** then the return value from sqlite3_complete16() will be non-zero 2332 ** regardless of whether or not the input SQL is complete.)^ 2333 ** 2334 ** The input to [sqlite3_complete()] must be a zero-terminated 2335 ** UTF-8 string. 2336 ** 2337 ** The input to [sqlite3_complete16()] must be a zero-terminated 2338 ** UTF-16 string in native byte order. 2339 */ 2340 SQLITE_API int sqlite3_complete(const char *sql); 2341 SQLITE_API int sqlite3_complete16(const void *sql); 2342 2343 /* 2344 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2345 ** KEYWORDS: {busy-handler callback} {busy handler} 2346 ** METHOD: sqlite3 2347 ** 2348 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2349 ** that might be invoked with argument P whenever 2350 ** an attempt is made to access a database table associated with 2351 ** [database connection] D when another thread 2352 ** or process has the table locked. 2353 ** The sqlite3_busy_handler() interface is used to implement 2354 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2355 ** 2356 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2357 ** is returned immediately upon encountering the lock. ^If the busy callback 2358 ** is not NULL, then the callback might be invoked with two arguments. 2359 ** 2360 ** ^The first argument to the busy handler is a copy of the void* pointer which 2361 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2362 ** the busy handler callback is the number of times that the busy handler has 2363 ** been invoked previously for the same locking event. ^If the 2364 ** busy callback returns 0, then no additional attempts are made to 2365 ** access the database and [SQLITE_BUSY] is returned 2366 ** to the application. 2367 ** ^If the callback returns non-zero, then another attempt 2368 ** is made to access the database and the cycle repeats. 2369 ** 2370 ** The presence of a busy handler does not guarantee that it will be invoked 2371 ** when there is lock contention. ^If SQLite determines that invoking the busy 2372 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2373 ** to the application instead of invoking the 2374 ** busy handler. 2375 ** Consider a scenario where one process is holding a read lock that 2376 ** it is trying to promote to a reserved lock and 2377 ** a second process is holding a reserved lock that it is trying 2378 ** to promote to an exclusive lock. The first process cannot proceed 2379 ** because it is blocked by the second and the second process cannot 2380 ** proceed because it is blocked by the first. If both processes 2381 ** invoke the busy handlers, neither will make any progress. Therefore, 2382 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2383 ** will induce the first process to release its read lock and allow 2384 ** the second process to proceed. 2385 ** 2386 ** ^The default busy callback is NULL. 2387 ** 2388 ** ^(There can only be a single busy handler defined for each 2389 ** [database connection]. Setting a new busy handler clears any 2390 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2391 ** or evaluating [PRAGMA busy_timeout=N] will change the 2392 ** busy handler and thus clear any previously set busy handler. 2393 ** 2394 ** The busy callback should not take any actions which modify the 2395 ** database connection that invoked the busy handler. In other words, 2396 ** the busy handler is not reentrant. Any such actions 2397 ** result in undefined behavior. 2398 ** 2399 ** A busy handler must not close the database connection 2400 ** or [prepared statement] that invoked the busy handler. 2401 */ 2402 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2403 2404 /* 2405 ** CAPI3REF: Set A Busy Timeout 2406 ** METHOD: sqlite3 2407 ** 2408 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2409 ** for a specified amount of time when a table is locked. ^The handler 2410 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2411 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2412 ** the handler returns 0 which causes [sqlite3_step()] to return 2413 ** [SQLITE_BUSY]. 2414 ** 2415 ** ^Calling this routine with an argument less than or equal to zero 2416 ** turns off all busy handlers. 2417 ** 2418 ** ^(There can only be a single busy handler for a particular 2419 ** [database connection] at any given moment. If another busy handler 2420 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2421 ** this routine, that other busy handler is cleared.)^ 2422 ** 2423 ** See also: [PRAGMA busy_timeout] 2424 */ 2425 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2426 2427 /* 2428 ** CAPI3REF: Convenience Routines For Running Queries 2429 ** METHOD: sqlite3 2430 ** 2431 ** This is a legacy interface that is preserved for backwards compatibility. 2432 ** Use of this interface is not recommended. 2433 ** 2434 ** Definition: A <b>result table</b> is memory data structure created by the 2435 ** [sqlite3_get_table()] interface. A result table records the 2436 ** complete query results from one or more queries. 2437 ** 2438 ** The table conceptually has a number of rows and columns. But 2439 ** these numbers are not part of the result table itself. These 2440 ** numbers are obtained separately. Let N be the number of rows 2441 ** and M be the number of columns. 2442 ** 2443 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2444 ** There are (N+1)*M elements in the array. The first M pointers point 2445 ** to zero-terminated strings that contain the names of the columns. 2446 ** The remaining entries all point to query results. NULL values result 2447 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2448 ** string representation as returned by [sqlite3_column_text()]. 2449 ** 2450 ** A result table might consist of one or more memory allocations. 2451 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2452 ** A result table should be deallocated using [sqlite3_free_table()]. 2453 ** 2454 ** ^(As an example of the result table format, suppose a query result 2455 ** is as follows: 2456 ** 2457 ** <blockquote><pre> 2458 ** Name | Age 2459 ** ----------------------- 2460 ** Alice | 43 2461 ** Bob | 28 2462 ** Cindy | 21 2463 ** </pre></blockquote> 2464 ** 2465 ** There are two column (M==2) and three rows (N==3). Thus the 2466 ** result table has 8 entries. Suppose the result table is stored 2467 ** in an array names azResult. Then azResult holds this content: 2468 ** 2469 ** <blockquote><pre> 2470 ** azResult[0] = "Name"; 2471 ** azResult[1] = "Age"; 2472 ** azResult[2] = "Alice"; 2473 ** azResult[3] = "43"; 2474 ** azResult[4] = "Bob"; 2475 ** azResult[5] = "28"; 2476 ** azResult[6] = "Cindy"; 2477 ** azResult[7] = "21"; 2478 ** </pre></blockquote>)^ 2479 ** 2480 ** ^The sqlite3_get_table() function evaluates one or more 2481 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2482 ** string of its 2nd parameter and returns a result table to the 2483 ** pointer given in its 3rd parameter. 2484 ** 2485 ** After the application has finished with the result from sqlite3_get_table(), 2486 ** it must pass the result table pointer to sqlite3_free_table() in order to 2487 ** release the memory that was malloced. Because of the way the 2488 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2489 ** function must not try to call [sqlite3_free()] directly. Only 2490 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2491 ** 2492 ** The sqlite3_get_table() interface is implemented as a wrapper around 2493 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2494 ** to any internal data structures of SQLite. It uses only the public 2495 ** interface defined here. As a consequence, errors that occur in the 2496 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2497 ** reflected in subsequent calls to [sqlite3_errcode()] or 2498 ** [sqlite3_errmsg()]. 2499 */ 2500 SQLITE_API int sqlite3_get_table( 2501 sqlite3 *db, /* An open database */ 2502 const char *zSql, /* SQL to be evaluated */ 2503 char ***pazResult, /* Results of the query */ 2504 int *pnRow, /* Number of result rows written here */ 2505 int *pnColumn, /* Number of result columns written here */ 2506 char **pzErrmsg /* Error msg written here */ 2507 ); 2508 SQLITE_API void sqlite3_free_table(char **result); 2509 2510 /* 2511 ** CAPI3REF: Formatted String Printing Functions 2512 ** 2513 ** These routines are work-alikes of the "printf()" family of functions 2514 ** from the standard C library. 2515 ** These routines understand most of the common formatting options from 2516 ** the standard library printf() 2517 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2518 ** See the [built-in printf()] documentation for details. 2519 ** 2520 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2521 ** results into memory obtained from [sqlite3_malloc64()]. 2522 ** The strings returned by these two routines should be 2523 ** released by [sqlite3_free()]. ^Both routines return a 2524 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2525 ** memory to hold the resulting string. 2526 ** 2527 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2528 ** the standard C library. The result is written into the 2529 ** buffer supplied as the second parameter whose size is given by 2530 ** the first parameter. Note that the order of the 2531 ** first two parameters is reversed from snprintf().)^ This is an 2532 ** historical accident that cannot be fixed without breaking 2533 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2534 ** returns a pointer to its buffer instead of the number of 2535 ** characters actually written into the buffer.)^ We admit that 2536 ** the number of characters written would be a more useful return 2537 ** value but we cannot change the implementation of sqlite3_snprintf() 2538 ** now without breaking compatibility. 2539 ** 2540 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2541 ** guarantees that the buffer is always zero-terminated. ^The first 2542 ** parameter "n" is the total size of the buffer, including space for 2543 ** the zero terminator. So the longest string that can be completely 2544 ** written will be n-1 characters. 2545 ** 2546 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2547 ** 2548 ** See also: [built-in printf()], [printf() SQL function] 2549 */ 2550 SQLITE_API char *sqlite3_mprintf(const char*,...); 2551 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2552 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2553 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2554 2555 /* 2556 ** CAPI3REF: Memory Allocation Subsystem 2557 ** 2558 ** The SQLite core uses these three routines for all of its own 2559 ** internal memory allocation needs. "Core" in the previous sentence 2560 ** does not include operating-system specific VFS implementation. The 2561 ** Windows VFS uses native malloc() and free() for some operations. 2562 ** 2563 ** ^The sqlite3_malloc() routine returns a pointer to a block 2564 ** of memory at least N bytes in length, where N is the parameter. 2565 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2566 ** memory, it returns a NULL pointer. ^If the parameter N to 2567 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2568 ** a NULL pointer. 2569 ** 2570 ** ^The sqlite3_malloc64(N) routine works just like 2571 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2572 ** of a signed 32-bit integer. 2573 ** 2574 ** ^Calling sqlite3_free() with a pointer previously returned 2575 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2576 ** that it might be reused. ^The sqlite3_free() routine is 2577 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2578 ** to sqlite3_free() is harmless. After being freed, memory 2579 ** should neither be read nor written. Even reading previously freed 2580 ** memory might result in a segmentation fault or other severe error. 2581 ** Memory corruption, a segmentation fault, or other severe error 2582 ** might result if sqlite3_free() is called with a non-NULL pointer that 2583 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2584 ** 2585 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2586 ** prior memory allocation X to be at least N bytes. 2587 ** ^If the X parameter to sqlite3_realloc(X,N) 2588 ** is a NULL pointer then its behavior is identical to calling 2589 ** sqlite3_malloc(N). 2590 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2591 ** negative then the behavior is exactly the same as calling 2592 ** sqlite3_free(X). 2593 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2594 ** of at least N bytes in size or NULL if insufficient memory is available. 2595 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2596 ** of the prior allocation are copied into the beginning of buffer returned 2597 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2598 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2599 ** prior allocation is not freed. 2600 ** 2601 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2602 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2603 ** of a 32-bit signed integer. 2604 ** 2605 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2606 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2607 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2608 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2609 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2610 ** sqlite3_msize(X) returns zero. If X points to something that is not 2611 ** the beginning of memory allocation, or if it points to a formerly 2612 ** valid memory allocation that has now been freed, then the behavior 2613 ** of sqlite3_msize(X) is undefined and possibly harmful. 2614 ** 2615 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2616 ** sqlite3_malloc64(), and sqlite3_realloc64() 2617 ** is always aligned to at least an 8 byte boundary, or to a 2618 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2619 ** option is used. 2620 ** 2621 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2622 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2623 ** implementation of these routines to be omitted. That capability 2624 ** is no longer provided. Only built-in memory allocators can be used. 2625 ** 2626 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2627 ** the system malloc() and free() directly when converting 2628 ** filenames between the UTF-8 encoding used by SQLite 2629 ** and whatever filename encoding is used by the particular Windows 2630 ** installation. Memory allocation errors were detected, but 2631 ** they were reported back as [SQLITE_CANTOPEN] or 2632 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2633 ** 2634 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2635 ** must be either NULL or else pointers obtained from a prior 2636 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2637 ** not yet been released. 2638 ** 2639 ** The application must not read or write any part of 2640 ** a block of memory after it has been released using 2641 ** [sqlite3_free()] or [sqlite3_realloc()]. 2642 */ 2643 SQLITE_API void *sqlite3_malloc(int); 2644 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2645 SQLITE_API void *sqlite3_realloc(void*, int); 2646 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2647 SQLITE_API void sqlite3_free(void*); 2648 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2649 2650 /* 2651 ** CAPI3REF: Memory Allocator Statistics 2652 ** 2653 ** SQLite provides these two interfaces for reporting on the status 2654 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2655 ** routines, which form the built-in memory allocation subsystem. 2656 ** 2657 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2658 ** of memory currently outstanding (malloced but not freed). 2659 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2660 ** value of [sqlite3_memory_used()] since the high-water mark 2661 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2662 ** [sqlite3_memory_highwater()] include any overhead 2663 ** added by SQLite in its implementation of [sqlite3_malloc()], 2664 ** but not overhead added by the any underlying system library 2665 ** routines that [sqlite3_malloc()] may call. 2666 ** 2667 ** ^The memory high-water mark is reset to the current value of 2668 ** [sqlite3_memory_used()] if and only if the parameter to 2669 ** [sqlite3_memory_highwater()] is true. ^The value returned 2670 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2671 ** prior to the reset. 2672 */ 2673 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2674 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2675 2676 /* 2677 ** CAPI3REF: Pseudo-Random Number Generator 2678 ** 2679 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2680 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2681 ** already uses the largest possible [ROWID]. The PRNG is also used for 2682 ** the build-in random() and randomblob() SQL functions. This interface allows 2683 ** applications to access the same PRNG for other purposes. 2684 ** 2685 ** ^A call to this routine stores N bytes of randomness into buffer P. 2686 ** ^The P parameter can be a NULL pointer. 2687 ** 2688 ** ^If this routine has not been previously called or if the previous 2689 ** call had N less than one or a NULL pointer for P, then the PRNG is 2690 ** seeded using randomness obtained from the xRandomness method of 2691 ** the default [sqlite3_vfs] object. 2692 ** ^If the previous call to this routine had an N of 1 or more and a 2693 ** non-NULL P then the pseudo-randomness is generated 2694 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2695 ** method. 2696 */ 2697 SQLITE_API void sqlite3_randomness(int N, void *P); 2698 2699 /* 2700 ** CAPI3REF: Compile-Time Authorization Callbacks 2701 ** METHOD: sqlite3 2702 ** KEYWORDS: {authorizer callback} 2703 ** 2704 ** ^This routine registers an authorizer callback with a particular 2705 ** [database connection], supplied in the first argument. 2706 ** ^The authorizer callback is invoked as SQL statements are being compiled 2707 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2708 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2709 ** and [sqlite3_prepare16_v3()]. ^At various 2710 ** points during the compilation process, as logic is being created 2711 ** to perform various actions, the authorizer callback is invoked to 2712 ** see if those actions are allowed. ^The authorizer callback should 2713 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2714 ** specific action but allow the SQL statement to continue to be 2715 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2716 ** rejected with an error. ^If the authorizer callback returns 2717 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2718 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2719 ** the authorizer will fail with an error message. 2720 ** 2721 ** When the callback returns [SQLITE_OK], that means the operation 2722 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2723 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2724 ** authorizer will fail with an error message explaining that 2725 ** access is denied. 2726 ** 2727 ** ^The first parameter to the authorizer callback is a copy of the third 2728 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2729 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2730 ** the particular action to be authorized. ^The third through sixth parameters 2731 ** to the callback are either NULL pointers or zero-terminated strings 2732 ** that contain additional details about the action to be authorized. 2733 ** Applications must always be prepared to encounter a NULL pointer in any 2734 ** of the third through the sixth parameters of the authorization callback. 2735 ** 2736 ** ^If the action code is [SQLITE_READ] 2737 ** and the callback returns [SQLITE_IGNORE] then the 2738 ** [prepared statement] statement is constructed to substitute 2739 ** a NULL value in place of the table column that would have 2740 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2741 ** return can be used to deny an untrusted user access to individual 2742 ** columns of a table. 2743 ** ^When a table is referenced by a [SELECT] but no column values are 2744 ** extracted from that table (for example in a query like 2745 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2746 ** is invoked once for that table with a column name that is an empty string. 2747 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2748 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2749 ** [truncate optimization] is disabled and all rows are deleted individually. 2750 ** 2751 ** An authorizer is used when [sqlite3_prepare | preparing] 2752 ** SQL statements from an untrusted source, to ensure that the SQL statements 2753 ** do not try to access data they are not allowed to see, or that they do not 2754 ** try to execute malicious statements that damage the database. For 2755 ** example, an application may allow a user to enter arbitrary 2756 ** SQL queries for evaluation by a database. But the application does 2757 ** not want the user to be able to make arbitrary changes to the 2758 ** database. An authorizer could then be put in place while the 2759 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2760 ** disallows everything except [SELECT] statements. 2761 ** 2762 ** Applications that need to process SQL from untrusted sources 2763 ** might also consider lowering resource limits using [sqlite3_limit()] 2764 ** and limiting database size using the [max_page_count] [PRAGMA] 2765 ** in addition to using an authorizer. 2766 ** 2767 ** ^(Only a single authorizer can be in place on a database connection 2768 ** at a time. Each call to sqlite3_set_authorizer overrides the 2769 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2770 ** The authorizer is disabled by default. 2771 ** 2772 ** The authorizer callback must not do anything that will modify 2773 ** the database connection that invoked the authorizer callback. 2774 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2775 ** database connections for the meaning of "modify" in this paragraph. 2776 ** 2777 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2778 ** statement might be re-prepared during [sqlite3_step()] due to a 2779 ** schema change. Hence, the application should ensure that the 2780 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2781 ** 2782 ** ^Note that the authorizer callback is invoked only during 2783 ** [sqlite3_prepare()] or its variants. Authorization is not 2784 ** performed during statement evaluation in [sqlite3_step()], unless 2785 ** as stated in the previous paragraph, sqlite3_step() invokes 2786 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2787 */ 2788 SQLITE_API int sqlite3_set_authorizer( 2789 sqlite3*, 2790 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2791 void *pUserData 2792 ); 2793 2794 /* 2795 ** CAPI3REF: Authorizer Return Codes 2796 ** 2797 ** The [sqlite3_set_authorizer | authorizer callback function] must 2798 ** return either [SQLITE_OK] or one of these two constants in order 2799 ** to signal SQLite whether or not the action is permitted. See the 2800 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2801 ** information. 2802 ** 2803 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2804 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2805 */ 2806 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2807 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2808 2809 /* 2810 ** CAPI3REF: Authorizer Action Codes 2811 ** 2812 ** The [sqlite3_set_authorizer()] interface registers a callback function 2813 ** that is invoked to authorize certain SQL statement actions. The 2814 ** second parameter to the callback is an integer code that specifies 2815 ** what action is being authorized. These are the integer action codes that 2816 ** the authorizer callback may be passed. 2817 ** 2818 ** These action code values signify what kind of operation is to be 2819 ** authorized. The 3rd and 4th parameters to the authorization 2820 ** callback function will be parameters or NULL depending on which of these 2821 ** codes is used as the second parameter. ^(The 5th parameter to the 2822 ** authorizer callback is the name of the database ("main", "temp", 2823 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2824 ** is the name of the inner-most trigger or view that is responsible for 2825 ** the access attempt or NULL if this access attempt is directly from 2826 ** top-level SQL code. 2827 */ 2828 /******************************************* 3rd ************ 4th ***********/ 2829 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2830 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2831 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2832 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2833 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2834 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2835 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2836 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2837 #define SQLITE_DELETE 9 /* Table Name NULL */ 2838 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2839 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2840 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2841 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2842 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2843 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2844 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2845 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2846 #define SQLITE_INSERT 18 /* Table Name NULL */ 2847 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2848 #define SQLITE_READ 20 /* Table Name Column Name */ 2849 #define SQLITE_SELECT 21 /* NULL NULL */ 2850 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2851 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2852 #define SQLITE_ATTACH 24 /* Filename NULL */ 2853 #define SQLITE_DETACH 25 /* Database Name NULL */ 2854 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2855 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2856 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2857 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2858 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2859 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2860 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2861 #define SQLITE_COPY 0 /* No longer used */ 2862 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2863 2864 /* 2865 ** CAPI3REF: Tracing And Profiling Functions 2866 ** METHOD: sqlite3 2867 ** 2868 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2869 ** instead of the routines described here. 2870 ** 2871 ** These routines register callback functions that can be used for 2872 ** tracing and profiling the execution of SQL statements. 2873 ** 2874 ** ^The callback function registered by sqlite3_trace() is invoked at 2875 ** various times when an SQL statement is being run by [sqlite3_step()]. 2876 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2877 ** SQL statement text as the statement first begins executing. 2878 ** ^(Additional sqlite3_trace() callbacks might occur 2879 ** as each triggered subprogram is entered. The callbacks for triggers 2880 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2881 ** 2882 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2883 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2884 ** 2885 ** ^The callback function registered by sqlite3_profile() is invoked 2886 ** as each SQL statement finishes. ^The profile callback contains 2887 ** the original statement text and an estimate of wall-clock time 2888 ** of how long that statement took to run. ^The profile callback 2889 ** time is in units of nanoseconds, however the current implementation 2890 ** is only capable of millisecond resolution so the six least significant 2891 ** digits in the time are meaningless. Future versions of SQLite 2892 ** might provide greater resolution on the profiler callback. The 2893 ** sqlite3_profile() function is considered experimental and is 2894 ** subject to change in future versions of SQLite. 2895 */ 2896 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2897 void(*xTrace)(void*,const char*), void*); 2898 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2899 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2900 2901 /* 2902 ** CAPI3REF: SQL Trace Event Codes 2903 ** KEYWORDS: SQLITE_TRACE 2904 ** 2905 ** These constants identify classes of events that can be monitored 2906 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 2907 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 2908 ** the following constants. ^The first argument to the trace callback 2909 ** is one of the following constants. 2910 ** 2911 ** New tracing constants may be added in future releases. 2912 ** 2913 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 2914 ** ^The T argument is one of the integer type codes above. 2915 ** ^The C argument is a copy of the context pointer passed in as the 2916 ** fourth argument to [sqlite3_trace_v2()]. 2917 ** The P and X arguments are pointers whose meanings depend on T. 2918 ** 2919 ** <dl> 2920 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2921 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2922 ** first begins running and possibly at other times during the 2923 ** execution of the prepared statement, such as at the start of each 2924 ** trigger subprogram. ^The P argument is a pointer to the 2925 ** [prepared statement]. ^The X argument is a pointer to a string which 2926 ** is the unexpanded SQL text of the prepared statement or an SQL comment 2927 ** that indicates the invocation of a trigger. ^The callback can compute 2928 ** the same text that would have been returned by the legacy [sqlite3_trace()] 2929 ** interface by using the X argument when X begins with "--" and invoking 2930 ** [sqlite3_expanded_sql(P)] otherwise. 2931 ** 2932 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2933 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2934 ** information as is provided by the [sqlite3_profile()] callback. 2935 ** ^The P argument is a pointer to the [prepared statement] and the 2936 ** X argument points to a 64-bit integer which is the estimated of 2937 ** the number of nanosecond that the prepared statement took to run. 2938 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2939 ** 2940 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2941 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2942 ** statement generates a single row of result. 2943 ** ^The P argument is a pointer to the [prepared statement] and the 2944 ** X argument is unused. 2945 ** 2946 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2947 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2948 ** connection closes. 2949 ** ^The P argument is a pointer to the [database connection] object 2950 ** and the X argument is unused. 2951 ** </dl> 2952 */ 2953 #define SQLITE_TRACE_STMT 0x01 2954 #define SQLITE_TRACE_PROFILE 0x02 2955 #define SQLITE_TRACE_ROW 0x04 2956 #define SQLITE_TRACE_CLOSE 0x08 2957 2958 /* 2959 ** CAPI3REF: SQL Trace Hook 2960 ** METHOD: sqlite3 2961 ** 2962 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2963 ** function X against [database connection] D, using property mask M 2964 ** and context pointer P. ^If the X callback is 2965 ** NULL or if the M mask is zero, then tracing is disabled. The 2966 ** M argument should be the bitwise OR-ed combination of 2967 ** zero or more [SQLITE_TRACE] constants. 2968 ** 2969 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2970 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2971 ** 2972 ** ^The X callback is invoked whenever any of the events identified by 2973 ** mask M occur. ^The integer return value from the callback is currently 2974 ** ignored, though this may change in future releases. Callback 2975 ** implementations should return zero to ensure future compatibility. 2976 ** 2977 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2978 ** ^The T argument is one of the [SQLITE_TRACE] 2979 ** constants to indicate why the callback was invoked. 2980 ** ^The C argument is a copy of the context pointer. 2981 ** The P and X arguments are pointers whose meanings depend on T. 2982 ** 2983 ** The sqlite3_trace_v2() interface is intended to replace the legacy 2984 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 2985 ** are deprecated. 2986 */ 2987 SQLITE_API int sqlite3_trace_v2( 2988 sqlite3*, 2989 unsigned uMask, 2990 int(*xCallback)(unsigned,void*,void*,void*), 2991 void *pCtx 2992 ); 2993 2994 /* 2995 ** CAPI3REF: Query Progress Callbacks 2996 ** METHOD: sqlite3 2997 ** 2998 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2999 ** function X to be invoked periodically during long running calls to 3000 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3001 ** database connection D. An example use for this 3002 ** interface is to keep a GUI updated during a large query. 3003 ** 3004 ** ^The parameter P is passed through as the only parameter to the 3005 ** callback function X. ^The parameter N is the approximate number of 3006 ** [virtual machine instructions] that are evaluated between successive 3007 ** invocations of the callback X. ^If N is less than one then the progress 3008 ** handler is disabled. 3009 ** 3010 ** ^Only a single progress handler may be defined at one time per 3011 ** [database connection]; setting a new progress handler cancels the 3012 ** old one. ^Setting parameter X to NULL disables the progress handler. 3013 ** ^The progress handler is also disabled by setting N to a value less 3014 ** than 1. 3015 ** 3016 ** ^If the progress callback returns non-zero, the operation is 3017 ** interrupted. This feature can be used to implement a 3018 ** "Cancel" button on a GUI progress dialog box. 3019 ** 3020 ** The progress handler callback must not do anything that will modify 3021 ** the database connection that invoked the progress handler. 3022 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3023 ** database connections for the meaning of "modify" in this paragraph. 3024 ** 3025 */ 3026 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3027 3028 /* 3029 ** CAPI3REF: Opening A New Database Connection 3030 ** CONSTRUCTOR: sqlite3 3031 ** 3032 ** ^These routines open an SQLite database file as specified by the 3033 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3034 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3035 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3036 ** returned in *ppDb, even if an error occurs. The only exception is that 3037 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3038 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3039 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3040 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3041 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3042 ** an English language description of the error following a failure of any 3043 ** of the sqlite3_open() routines. 3044 ** 3045 ** ^The default encoding will be UTF-8 for databases created using 3046 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3047 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3048 ** 3049 ** Whether or not an error occurs when it is opened, resources 3050 ** associated with the [database connection] handle should be released by 3051 ** passing it to [sqlite3_close()] when it is no longer required. 3052 ** 3053 ** The sqlite3_open_v2() interface works like sqlite3_open() 3054 ** except that it accepts two additional parameters for additional control 3055 ** over the new database connection. ^(The flags parameter to 3056 ** sqlite3_open_v2() can take one of 3057 ** the following three values, optionally combined with the 3058 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3059 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3060 ** 3061 ** <dl> 3062 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3063 ** <dd>The database is opened in read-only mode. If the database does not 3064 ** already exist, an error is returned.</dd>)^ 3065 ** 3066 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3067 ** <dd>The database is opened for reading and writing if possible, or reading 3068 ** only if the file is write protected by the operating system. In either 3069 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3070 ** 3071 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3072 ** <dd>The database is opened for reading and writing, and is created if 3073 ** it does not already exist. This is the behavior that is always used for 3074 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3075 ** </dl> 3076 ** 3077 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3078 ** combinations shown above optionally combined with other 3079 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3080 ** then the behavior is undefined. 3081 ** 3082 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3083 ** opens in the multi-thread [threading mode] as long as the single-thread 3084 ** mode has not been set at compile-time or start-time. ^If the 3085 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3086 ** in the serialized [threading mode] unless single-thread was 3087 ** previously selected at compile-time or start-time. 3088 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3089 ** eligible to use [shared cache mode], regardless of whether or not shared 3090 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3091 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3092 ** participate in [shared cache mode] even if it is enabled. 3093 ** 3094 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3095 ** [sqlite3_vfs] object that defines the operating system interface that 3096 ** the new database connection should use. ^If the fourth parameter is 3097 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3098 ** 3099 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3100 ** is created for the connection. ^This in-memory database will vanish when 3101 ** the database connection is closed. Future versions of SQLite might 3102 ** make use of additional special filenames that begin with the ":" character. 3103 ** It is recommended that when a database filename actually does begin with 3104 ** a ":" character you should prefix the filename with a pathname such as 3105 ** "./" to avoid ambiguity. 3106 ** 3107 ** ^If the filename is an empty string, then a private, temporary 3108 ** on-disk database will be created. ^This private database will be 3109 ** automatically deleted as soon as the database connection is closed. 3110 ** 3111 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3112 ** 3113 ** ^If [URI filename] interpretation is enabled, and the filename argument 3114 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3115 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3116 ** set in the third argument to sqlite3_open_v2(), or if it has 3117 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3118 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3119 ** URI filename interpretation is turned off 3120 ** by default, but future releases of SQLite might enable URI filename 3121 ** interpretation by default. See "[URI filenames]" for additional 3122 ** information. 3123 ** 3124 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3125 ** authority, then it must be either an empty string or the string 3126 ** "localhost". ^If the authority is not an empty string or "localhost", an 3127 ** error is returned to the caller. ^The fragment component of a URI, if 3128 ** present, is ignored. 3129 ** 3130 ** ^SQLite uses the path component of the URI as the name of the disk file 3131 ** which contains the database. ^If the path begins with a '/' character, 3132 ** then it is interpreted as an absolute path. ^If the path does not begin 3133 ** with a '/' (meaning that the authority section is omitted from the URI) 3134 ** then the path is interpreted as a relative path. 3135 ** ^(On windows, the first component of an absolute path 3136 ** is a drive specification (e.g. "C:").)^ 3137 ** 3138 ** [[core URI query parameters]] 3139 ** The query component of a URI may contain parameters that are interpreted 3140 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3141 ** SQLite and its built-in [VFSes] interpret the 3142 ** following query parameters: 3143 ** 3144 ** <ul> 3145 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3146 ** a VFS object that provides the operating system interface that should 3147 ** be used to access the database file on disk. ^If this option is set to 3148 ** an empty string the default VFS object is used. ^Specifying an unknown 3149 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3150 ** present, then the VFS specified by the option takes precedence over 3151 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3152 ** 3153 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3154 ** "rwc", or "memory". Attempting to set it to any other value is 3155 ** an error)^. 3156 ** ^If "ro" is specified, then the database is opened for read-only 3157 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3158 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3159 ** "rw", then the database is opened for read-write (but not create) 3160 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3161 ** been set. ^Value "rwc" is equivalent to setting both 3162 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3163 ** set to "memory" then a pure [in-memory database] that never reads 3164 ** or writes from disk is used. ^It is an error to specify a value for 3165 ** the mode parameter that is less restrictive than that specified by 3166 ** the flags passed in the third parameter to sqlite3_open_v2(). 3167 ** 3168 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3169 ** "private". ^Setting it to "shared" is equivalent to setting the 3170 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3171 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3172 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3173 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3174 ** a URI filename, its value overrides any behavior requested by setting 3175 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3176 ** 3177 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3178 ** [powersafe overwrite] property does or does not apply to the 3179 ** storage media on which the database file resides. 3180 ** 3181 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3182 ** which if set disables file locking in rollback journal modes. This 3183 ** is useful for accessing a database on a filesystem that does not 3184 ** support locking. Caution: Database corruption might result if two 3185 ** or more processes write to the same database and any one of those 3186 ** processes uses nolock=1. 3187 ** 3188 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3189 ** parameter that indicates that the database file is stored on 3190 ** read-only media. ^When immutable is set, SQLite assumes that the 3191 ** database file cannot be changed, even by a process with higher 3192 ** privilege, and so the database is opened read-only and all locking 3193 ** and change detection is disabled. Caution: Setting the immutable 3194 ** property on a database file that does in fact change can result 3195 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3196 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3197 ** 3198 ** </ul> 3199 ** 3200 ** ^Specifying an unknown parameter in the query component of a URI is not an 3201 ** error. Future versions of SQLite might understand additional query 3202 ** parameters. See "[query parameters with special meaning to SQLite]" for 3203 ** additional information. 3204 ** 3205 ** [[URI filename examples]] <h3>URI filename examples</h3> 3206 ** 3207 ** <table border="1" align=center cellpadding=5> 3208 ** <tr><th> URI filenames <th> Results 3209 ** <tr><td> file:data.db <td> 3210 ** Open the file "data.db" in the current directory. 3211 ** <tr><td> file:/home/fred/data.db<br> 3212 ** file:///home/fred/data.db <br> 3213 ** file://localhost/home/fred/data.db <br> <td> 3214 ** Open the database file "/home/fred/data.db". 3215 ** <tr><td> file://darkstar/home/fred/data.db <td> 3216 ** An error. "darkstar" is not a recognized authority. 3217 ** <tr><td style="white-space:nowrap"> 3218 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3219 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3220 ** C:. Note that the %20 escaping in this example is not strictly 3221 ** necessary - space characters can be used literally 3222 ** in URI filenames. 3223 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3224 ** Open file "data.db" in the current directory for read-only access. 3225 ** Regardless of whether or not shared-cache mode is enabled by 3226 ** default, use a private cache. 3227 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3228 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3229 ** that uses dot-files in place of posix advisory locking. 3230 ** <tr><td> file:data.db?mode=readonly <td> 3231 ** An error. "readonly" is not a valid option for the "mode" parameter. 3232 ** </table> 3233 ** 3234 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3235 ** query components of a URI. A hexadecimal escape sequence consists of a 3236 ** percent sign - "%" - followed by exactly two hexadecimal digits 3237 ** specifying an octet value. ^Before the path or query components of a 3238 ** URI filename are interpreted, they are encoded using UTF-8 and all 3239 ** hexadecimal escape sequences replaced by a single byte containing the 3240 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3241 ** the results are undefined. 3242 ** 3243 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3244 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3245 ** codepage is currently defined. Filenames containing international 3246 ** characters must be converted to UTF-8 prior to passing them into 3247 ** sqlite3_open() or sqlite3_open_v2(). 3248 ** 3249 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3250 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3251 ** features that require the use of temporary files may fail. 3252 ** 3253 ** See also: [sqlite3_temp_directory] 3254 */ 3255 SQLITE_API int sqlite3_open( 3256 const char *filename, /* Database filename (UTF-8) */ 3257 sqlite3 **ppDb /* OUT: SQLite db handle */ 3258 ); 3259 SQLITE_API int sqlite3_open16( 3260 const void *filename, /* Database filename (UTF-16) */ 3261 sqlite3 **ppDb /* OUT: SQLite db handle */ 3262 ); 3263 SQLITE_API int sqlite3_open_v2( 3264 const char *filename, /* Database filename (UTF-8) */ 3265 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3266 int flags, /* Flags */ 3267 const char *zVfs /* Name of VFS module to use */ 3268 ); 3269 3270 /* 3271 ** CAPI3REF: Obtain Values For URI Parameters 3272 ** 3273 ** These are utility routines, useful to VFS implementations, that check 3274 ** to see if a database file was a URI that contained a specific query 3275 ** parameter, and if so obtains the value of that query parameter. 3276 ** 3277 ** If F is the database filename pointer passed into the xOpen() method of 3278 ** a VFS implementation when the flags parameter to xOpen() has one or 3279 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3280 ** P is the name of the query parameter, then 3281 ** sqlite3_uri_parameter(F,P) returns the value of the P 3282 ** parameter if it exists or a NULL pointer if P does not appear as a 3283 ** query parameter on F. If P is a query parameter of F 3284 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3285 ** a pointer to an empty string. 3286 ** 3287 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3288 ** parameter and returns true (1) or false (0) according to the value 3289 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3290 ** value of query parameter P is one of "yes", "true", or "on" in any 3291 ** case or if the value begins with a non-zero number. The 3292 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3293 ** query parameter P is one of "no", "false", or "off" in any case or 3294 ** if the value begins with a numeric zero. If P is not a query 3295 ** parameter on F or if the value of P is does not match any of the 3296 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3297 ** 3298 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3299 ** 64-bit signed integer and returns that integer, or D if P does not 3300 ** exist. If the value of P is something other than an integer, then 3301 ** zero is returned. 3302 ** 3303 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3304 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3305 ** is not a database file pathname pointer that SQLite passed into the xOpen 3306 ** VFS method, then the behavior of this routine is undefined and probably 3307 ** undesirable. 3308 */ 3309 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3310 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3311 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3312 3313 3314 /* 3315 ** CAPI3REF: Error Codes And Messages 3316 ** METHOD: sqlite3 3317 ** 3318 ** ^If the most recent sqlite3_* API call associated with 3319 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3320 ** returns the numeric [result code] or [extended result code] for that 3321 ** API call. 3322 ** If the most recent API call was successful, 3323 ** then the return value from sqlite3_errcode() is undefined. 3324 ** ^The sqlite3_extended_errcode() 3325 ** interface is the same except that it always returns the 3326 ** [extended result code] even when extended result codes are 3327 ** disabled. 3328 ** 3329 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3330 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3331 ** ^(Memory to hold the error message string is managed internally. 3332 ** The application does not need to worry about freeing the result. 3333 ** However, the error string might be overwritten or deallocated by 3334 ** subsequent calls to other SQLite interface functions.)^ 3335 ** 3336 ** ^The sqlite3_errstr() interface returns the English-language text 3337 ** that describes the [result code], as UTF-8. 3338 ** ^(Memory to hold the error message string is managed internally 3339 ** and must not be freed by the application)^. 3340 ** 3341 ** When the serialized [threading mode] is in use, it might be the 3342 ** case that a second error occurs on a separate thread in between 3343 ** the time of the first error and the call to these interfaces. 3344 ** When that happens, the second error will be reported since these 3345 ** interfaces always report the most recent result. To avoid 3346 ** this, each thread can obtain exclusive use of the [database connection] D 3347 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3348 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3349 ** all calls to the interfaces listed here are completed. 3350 ** 3351 ** If an interface fails with SQLITE_MISUSE, that means the interface 3352 ** was invoked incorrectly by the application. In that case, the 3353 ** error code and message may or may not be set. 3354 */ 3355 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3356 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3357 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3358 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3359 SQLITE_API const char *sqlite3_errstr(int); 3360 3361 /* 3362 ** CAPI3REF: Prepared Statement Object 3363 ** KEYWORDS: {prepared statement} {prepared statements} 3364 ** 3365 ** An instance of this object represents a single SQL statement that 3366 ** has been compiled into binary form and is ready to be evaluated. 3367 ** 3368 ** Think of each SQL statement as a separate computer program. The 3369 ** original SQL text is source code. A prepared statement object 3370 ** is the compiled object code. All SQL must be converted into a 3371 ** prepared statement before it can be run. 3372 ** 3373 ** The life-cycle of a prepared statement object usually goes like this: 3374 ** 3375 ** <ol> 3376 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3377 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3378 ** interfaces. 3379 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3380 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3381 ** to step 2. Do this zero or more times. 3382 ** <li> Destroy the object using [sqlite3_finalize()]. 3383 ** </ol> 3384 */ 3385 typedef struct sqlite3_stmt sqlite3_stmt; 3386 3387 /* 3388 ** CAPI3REF: Run-time Limits 3389 ** METHOD: sqlite3 3390 ** 3391 ** ^(This interface allows the size of various constructs to be limited 3392 ** on a connection by connection basis. The first parameter is the 3393 ** [database connection] whose limit is to be set or queried. The 3394 ** second parameter is one of the [limit categories] that define a 3395 ** class of constructs to be size limited. The third parameter is the 3396 ** new limit for that construct.)^ 3397 ** 3398 ** ^If the new limit is a negative number, the limit is unchanged. 3399 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3400 ** [limits | hard upper bound] 3401 ** set at compile-time by a C preprocessor macro called 3402 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3403 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3404 ** ^Attempts to increase a limit above its hard upper bound are 3405 ** silently truncated to the hard upper bound. 3406 ** 3407 ** ^Regardless of whether or not the limit was changed, the 3408 ** [sqlite3_limit()] interface returns the prior value of the limit. 3409 ** ^Hence, to find the current value of a limit without changing it, 3410 ** simply invoke this interface with the third parameter set to -1. 3411 ** 3412 ** Run-time limits are intended for use in applications that manage 3413 ** both their own internal database and also databases that are controlled 3414 ** by untrusted external sources. An example application might be a 3415 ** web browser that has its own databases for storing history and 3416 ** separate databases controlled by JavaScript applications downloaded 3417 ** off the Internet. The internal databases can be given the 3418 ** large, default limits. Databases managed by external sources can 3419 ** be given much smaller limits designed to prevent a denial of service 3420 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3421 ** interface to further control untrusted SQL. The size of the database 3422 ** created by an untrusted script can be contained using the 3423 ** [max_page_count] [PRAGMA]. 3424 ** 3425 ** New run-time limit categories may be added in future releases. 3426 */ 3427 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3428 3429 /* 3430 ** CAPI3REF: Run-Time Limit Categories 3431 ** KEYWORDS: {limit category} {*limit categories} 3432 ** 3433 ** These constants define various performance limits 3434 ** that can be lowered at run-time using [sqlite3_limit()]. 3435 ** The synopsis of the meanings of the various limits is shown below. 3436 ** Additional information is available at [limits | Limits in SQLite]. 3437 ** 3438 ** <dl> 3439 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3440 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3441 ** 3442 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3443 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3444 ** 3445 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3446 ** <dd>The maximum number of columns in a table definition or in the 3447 ** result set of a [SELECT] or the maximum number of columns in an index 3448 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3449 ** 3450 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3451 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3452 ** 3453 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3454 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3455 ** 3456 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3457 ** <dd>The maximum number of instructions in a virtual machine program 3458 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3459 ** the equivalent tries to allocate space for more than this many opcodes 3460 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3461 ** 3462 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3463 ** <dd>The maximum number of arguments on a function.</dd>)^ 3464 ** 3465 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3466 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3467 ** 3468 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3469 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3470 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3471 ** [GLOB] operators.</dd>)^ 3472 ** 3473 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3474 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3475 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3476 ** 3477 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3478 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3479 ** 3480 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3481 ** <dd>The maximum number of auxiliary worker threads that a single 3482 ** [prepared statement] may start.</dd>)^ 3483 ** </dl> 3484 */ 3485 #define SQLITE_LIMIT_LENGTH 0 3486 #define SQLITE_LIMIT_SQL_LENGTH 1 3487 #define SQLITE_LIMIT_COLUMN 2 3488 #define SQLITE_LIMIT_EXPR_DEPTH 3 3489 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3490 #define SQLITE_LIMIT_VDBE_OP 5 3491 #define SQLITE_LIMIT_FUNCTION_ARG 6 3492 #define SQLITE_LIMIT_ATTACHED 7 3493 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3494 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3495 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3496 #define SQLITE_LIMIT_WORKER_THREADS 11 3497 3498 /* 3499 ** CAPI3REF: Prepare Flags 3500 ** 3501 ** These constants define various flags that can be passed into 3502 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3503 ** [sqlite3_prepare16_v3()] interfaces. 3504 ** 3505 ** New flags may be added in future releases of SQLite. 3506 ** 3507 ** <dl> 3508 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3509 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3510 ** that the prepared statement will be retained for a long time and 3511 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3512 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3513 ** be used just once or at most a few times and then destroyed using 3514 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3515 ** on this hint by avoiding the use of [lookaside memory] so as not to 3516 ** deplete the limited store of lookaside memory. Future versions of 3517 ** SQLite may act on this hint differently. 3518 ** </dl> 3519 */ 3520 #define SQLITE_PREPARE_PERSISTENT 0x01 3521 3522 /* 3523 ** CAPI3REF: Compiling An SQL Statement 3524 ** KEYWORDS: {SQL statement compiler} 3525 ** METHOD: sqlite3 3526 ** CONSTRUCTOR: sqlite3_stmt 3527 ** 3528 ** To execute an SQL statement, it must first be compiled into a byte-code 3529 ** program using one of these routines. Or, in other words, these routines 3530 ** are constructors for the [prepared statement] object. 3531 ** 3532 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3533 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3534 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3535 ** for special purposes. 3536 ** 3537 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3538 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3539 ** as a convenience. The UTF-16 interfaces work by converting the 3540 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3541 ** 3542 ** The first argument, "db", is a [database connection] obtained from a 3543 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3544 ** [sqlite3_open16()]. The database connection must not have been closed. 3545 ** 3546 ** The second argument, "zSql", is the statement to be compiled, encoded 3547 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3548 ** and sqlite3_prepare_v3() 3549 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3550 ** and sqlite3_prepare16_v3() use UTF-16. 3551 ** 3552 ** ^If the nByte argument is negative, then zSql is read up to the 3553 ** first zero terminator. ^If nByte is positive, then it is the 3554 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3555 ** statement is generated. 3556 ** If the caller knows that the supplied string is nul-terminated, then 3557 ** there is a small performance advantage to passing an nByte parameter that 3558 ** is the number of bytes in the input string <i>including</i> 3559 ** the nul-terminator. 3560 ** 3561 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3562 ** past the end of the first SQL statement in zSql. These routines only 3563 ** compile the first statement in zSql, so *pzTail is left pointing to 3564 ** what remains uncompiled. 3565 ** 3566 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3567 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3568 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3569 ** string or a comment) then *ppStmt is set to NULL. 3570 ** The calling procedure is responsible for deleting the compiled 3571 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3572 ** ppStmt may not be NULL. 3573 ** 3574 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3575 ** otherwise an [error code] is returned. 3576 ** 3577 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3578 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3579 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3580 ** are retained for backwards compatibility, but their use is discouraged. 3581 ** ^In the "vX" interfaces, the prepared statement 3582 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3583 ** original SQL text. This causes the [sqlite3_step()] interface to 3584 ** behave differently in three ways: 3585 ** 3586 ** <ol> 3587 ** <li> 3588 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3589 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3590 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3591 ** retries will occur before sqlite3_step() gives up and returns an error. 3592 ** </li> 3593 ** 3594 ** <li> 3595 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3596 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3597 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3598 ** and the application would have to make a second call to [sqlite3_reset()] 3599 ** in order to find the underlying cause of the problem. With the "v2" prepare 3600 ** interfaces, the underlying reason for the error is returned immediately. 3601 ** </li> 3602 ** 3603 ** <li> 3604 ** ^If the specific value bound to [parameter | host parameter] in the 3605 ** WHERE clause might influence the choice of query plan for a statement, 3606 ** then the statement will be automatically recompiled, as if there had been 3607 ** a schema change, on the first [sqlite3_step()] call following any change 3608 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3609 ** ^The specific value of WHERE-clause [parameter] might influence the 3610 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3611 ** or [GLOB] operator or if the parameter is compared to an indexed column 3612 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3613 ** </li> 3614 ** </ol> 3615 ** 3616 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3617 ** the extra prepFlags parameter, which is a bit array consisting of zero or 3618 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3619 ** sqlite3_prepare_v2() interface works exactly the same as 3620 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 3621 */ 3622 SQLITE_API int sqlite3_prepare( 3623 sqlite3 *db, /* Database handle */ 3624 const char *zSql, /* SQL statement, UTF-8 encoded */ 3625 int nByte, /* Maximum length of zSql in bytes. */ 3626 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3627 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3628 ); 3629 SQLITE_API int sqlite3_prepare_v2( 3630 sqlite3 *db, /* Database handle */ 3631 const char *zSql, /* SQL statement, UTF-8 encoded */ 3632 int nByte, /* Maximum length of zSql in bytes. */ 3633 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3634 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3635 ); 3636 SQLITE_API int sqlite3_prepare_v3( 3637 sqlite3 *db, /* Database handle */ 3638 const char *zSql, /* SQL statement, UTF-8 encoded */ 3639 int nByte, /* Maximum length of zSql in bytes. */ 3640 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3641 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3642 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3643 ); 3644 SQLITE_API int sqlite3_prepare16( 3645 sqlite3 *db, /* Database handle */ 3646 const void *zSql, /* SQL statement, UTF-16 encoded */ 3647 int nByte, /* Maximum length of zSql in bytes. */ 3648 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3649 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3650 ); 3651 SQLITE_API int sqlite3_prepare16_v2( 3652 sqlite3 *db, /* Database handle */ 3653 const void *zSql, /* SQL statement, UTF-16 encoded */ 3654 int nByte, /* Maximum length of zSql in bytes. */ 3655 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3656 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3657 ); 3658 SQLITE_API int sqlite3_prepare16_v3( 3659 sqlite3 *db, /* Database handle */ 3660 const void *zSql, /* SQL statement, UTF-16 encoded */ 3661 int nByte, /* Maximum length of zSql in bytes. */ 3662 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3663 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3664 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3665 ); 3666 3667 /* 3668 ** CAPI3REF: Retrieving Statement SQL 3669 ** METHOD: sqlite3_stmt 3670 ** 3671 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3672 ** SQL text used to create [prepared statement] P if P was 3673 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3674 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3675 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3676 ** string containing the SQL text of prepared statement P with 3677 ** [bound parameters] expanded. 3678 ** 3679 ** ^(For example, if a prepared statement is created using the SQL 3680 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3681 ** and parameter :xyz is unbound, then sqlite3_sql() will return 3682 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3683 ** will return "SELECT 2345,NULL".)^ 3684 ** 3685 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3686 ** is available to hold the result, or if the result would exceed the 3687 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3688 ** 3689 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3690 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3691 ** option causes sqlite3_expanded_sql() to always return NULL. 3692 ** 3693 ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3694 ** automatically freed when the prepared statement is finalized. 3695 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3696 ** is obtained from [sqlite3_malloc()] and must be free by the application 3697 ** by passing it to [sqlite3_free()]. 3698 */ 3699 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3700 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3701 3702 /* 3703 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3704 ** METHOD: sqlite3_stmt 3705 ** 3706 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3707 ** and only if the [prepared statement] X makes no direct changes to 3708 ** the content of the database file. 3709 ** 3710 ** Note that [application-defined SQL functions] or 3711 ** [virtual tables] might change the database indirectly as a side effect. 3712 ** ^(For example, if an application defines a function "eval()" that 3713 ** calls [sqlite3_exec()], then the following SQL statement would 3714 ** change the database file through side-effects: 3715 ** 3716 ** <blockquote><pre> 3717 ** SELECT eval('DELETE FROM t1') FROM t2; 3718 ** </pre></blockquote> 3719 ** 3720 ** But because the [SELECT] statement does not change the database file 3721 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3722 ** 3723 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3724 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3725 ** since the statements themselves do not actually modify the database but 3726 ** rather they control the timing of when other statements modify the 3727 ** database. ^The [ATTACH] and [DETACH] statements also cause 3728 ** sqlite3_stmt_readonly() to return true since, while those statements 3729 ** change the configuration of a database connection, they do not make 3730 ** changes to the content of the database files on disk. 3731 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3732 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3733 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3734 ** sqlite3_stmt_readonly() returns false for those commands. 3735 */ 3736 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3737 3738 /* 3739 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3740 ** METHOD: sqlite3_stmt 3741 ** 3742 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3743 ** [prepared statement] S has been stepped at least once using 3744 ** [sqlite3_step(S)] but has neither run to completion (returned 3745 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3746 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3747 ** interface returns false if S is a NULL pointer. If S is not a 3748 ** NULL pointer and is not a pointer to a valid [prepared statement] 3749 ** object, then the behavior is undefined and probably undesirable. 3750 ** 3751 ** This interface can be used in combination [sqlite3_next_stmt()] 3752 ** to locate all prepared statements associated with a database 3753 ** connection that are in need of being reset. This can be used, 3754 ** for example, in diagnostic routines to search for prepared 3755 ** statements that are holding a transaction open. 3756 */ 3757 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3758 3759 /* 3760 ** CAPI3REF: Dynamically Typed Value Object 3761 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3762 ** 3763 ** SQLite uses the sqlite3_value object to represent all values 3764 ** that can be stored in a database table. SQLite uses dynamic typing 3765 ** for the values it stores. ^Values stored in sqlite3_value objects 3766 ** can be integers, floating point values, strings, BLOBs, or NULL. 3767 ** 3768 ** An sqlite3_value object may be either "protected" or "unprotected". 3769 ** Some interfaces require a protected sqlite3_value. Other interfaces 3770 ** will accept either a protected or an unprotected sqlite3_value. 3771 ** Every interface that accepts sqlite3_value arguments specifies 3772 ** whether or not it requires a protected sqlite3_value. The 3773 ** [sqlite3_value_dup()] interface can be used to construct a new 3774 ** protected sqlite3_value from an unprotected sqlite3_value. 3775 ** 3776 ** The terms "protected" and "unprotected" refer to whether or not 3777 ** a mutex is held. An internal mutex is held for a protected 3778 ** sqlite3_value object but no mutex is held for an unprotected 3779 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3780 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3781 ** or if SQLite is run in one of reduced mutex modes 3782 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3783 ** then there is no distinction between protected and unprotected 3784 ** sqlite3_value objects and they can be used interchangeably. However, 3785 ** for maximum code portability it is recommended that applications 3786 ** still make the distinction between protected and unprotected 3787 ** sqlite3_value objects even when not strictly required. 3788 ** 3789 ** ^The sqlite3_value objects that are passed as parameters into the 3790 ** implementation of [application-defined SQL functions] are protected. 3791 ** ^The sqlite3_value object returned by 3792 ** [sqlite3_column_value()] is unprotected. 3793 ** Unprotected sqlite3_value objects may only be used as arguments 3794 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3795 ** [sqlite3_value_dup()]. 3796 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3797 ** interfaces require protected sqlite3_value objects. 3798 */ 3799 typedef struct sqlite3_value sqlite3_value; 3800 3801 /* 3802 ** CAPI3REF: SQL Function Context Object 3803 ** 3804 ** The context in which an SQL function executes is stored in an 3805 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3806 ** is always first parameter to [application-defined SQL functions]. 3807 ** The application-defined SQL function implementation will pass this 3808 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3809 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3810 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3811 ** and/or [sqlite3_set_auxdata()]. 3812 */ 3813 typedef struct sqlite3_context sqlite3_context; 3814 3815 /* 3816 ** CAPI3REF: Binding Values To Prepared Statements 3817 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3818 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3819 ** METHOD: sqlite3_stmt 3820 ** 3821 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3822 ** literals may be replaced by a [parameter] that matches one of following 3823 ** templates: 3824 ** 3825 ** <ul> 3826 ** <li> ? 3827 ** <li> ?NNN 3828 ** <li> :VVV 3829 ** <li> @VVV 3830 ** <li> $VVV 3831 ** </ul> 3832 ** 3833 ** In the templates above, NNN represents an integer literal, 3834 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3835 ** parameters (also called "host parameter names" or "SQL parameters") 3836 ** can be set using the sqlite3_bind_*() routines defined here. 3837 ** 3838 ** ^The first argument to the sqlite3_bind_*() routines is always 3839 ** a pointer to the [sqlite3_stmt] object returned from 3840 ** [sqlite3_prepare_v2()] or its variants. 3841 ** 3842 ** ^The second argument is the index of the SQL parameter to be set. 3843 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3844 ** SQL parameter is used more than once, second and subsequent 3845 ** occurrences have the same index as the first occurrence. 3846 ** ^The index for named parameters can be looked up using the 3847 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3848 ** for "?NNN" parameters is the value of NNN. 3849 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3850 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3851 ** 3852 ** ^The third argument is the value to bind to the parameter. 3853 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3854 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3855 ** is ignored and the end result is the same as sqlite3_bind_null(). 3856 ** 3857 ** ^(In those routines that have a fourth argument, its value is the 3858 ** number of bytes in the parameter. To be clear: the value is the 3859 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3860 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3861 ** is negative, then the length of the string is 3862 ** the number of bytes up to the first zero terminator. 3863 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3864 ** the behavior is undefined. 3865 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3866 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3867 ** that parameter must be the byte offset 3868 ** where the NUL terminator would occur assuming the string were NUL 3869 ** terminated. If any NUL characters occur at byte offsets less than 3870 ** the value of the fourth parameter then the resulting string value will 3871 ** contain embedded NULs. The result of expressions involving strings 3872 ** with embedded NULs is undefined. 3873 ** 3874 ** ^The fifth argument to the BLOB and string binding interfaces 3875 ** is a destructor used to dispose of the BLOB or 3876 ** string after SQLite has finished with it. ^The destructor is called 3877 ** to dispose of the BLOB or string even if the call to bind API fails. 3878 ** ^If the fifth argument is 3879 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3880 ** information is in static, unmanaged space and does not need to be freed. 3881 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3882 ** SQLite makes its own private copy of the data immediately, before 3883 ** the sqlite3_bind_*() routine returns. 3884 ** 3885 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3886 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3887 ** to specify the encoding of the text in the third parameter. If 3888 ** the sixth argument to sqlite3_bind_text64() is not one of the 3889 ** allowed values shown above, or if the text encoding is different 3890 ** from the encoding specified by the sixth parameter, then the behavior 3891 ** is undefined. 3892 ** 3893 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3894 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3895 ** (just an integer to hold its size) while it is being processed. 3896 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3897 ** content is later written using 3898 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3899 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3900 ** 3901 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 3902 ** [prepared statement] S to have an SQL value of NULL, but to also be 3903 ** associated with the pointer P of type T. ^D is either a NULL pointer or 3904 ** a pointer to a destructor function for P. ^SQLite will invoke the 3905 ** destructor D with a single argument of P when it is finished using 3906 ** P. The T parameter should be a static string, preferably a string 3907 ** literal. The sqlite3_bind_pointer() routine is part of the 3908 ** [pointer passing interface] added for SQLite 3.20.0. 3909 ** 3910 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3911 ** for the [prepared statement] or with a prepared statement for which 3912 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3913 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3914 ** routine is passed a [prepared statement] that has been finalized, the 3915 ** result is undefined and probably harmful. 3916 ** 3917 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3918 ** ^Unbound parameters are interpreted as NULL. 3919 ** 3920 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3921 ** [error code] if anything goes wrong. 3922 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3923 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3924 ** [SQLITE_MAX_LENGTH]. 3925 ** ^[SQLITE_RANGE] is returned if the parameter 3926 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3927 ** 3928 ** See also: [sqlite3_bind_parameter_count()], 3929 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3930 */ 3931 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3932 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3933 void(*)(void*)); 3934 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3935 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3936 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3937 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3938 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3939 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3940 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3941 void(*)(void*), unsigned char encoding); 3942 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3943 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 3944 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3945 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3946 3947 /* 3948 ** CAPI3REF: Number Of SQL Parameters 3949 ** METHOD: sqlite3_stmt 3950 ** 3951 ** ^This routine can be used to find the number of [SQL parameters] 3952 ** in a [prepared statement]. SQL parameters are tokens of the 3953 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3954 ** placeholders for values that are [sqlite3_bind_blob | bound] 3955 ** to the parameters at a later time. 3956 ** 3957 ** ^(This routine actually returns the index of the largest (rightmost) 3958 ** parameter. For all forms except ?NNN, this will correspond to the 3959 ** number of unique parameters. If parameters of the ?NNN form are used, 3960 ** there may be gaps in the list.)^ 3961 ** 3962 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3963 ** [sqlite3_bind_parameter_name()], and 3964 ** [sqlite3_bind_parameter_index()]. 3965 */ 3966 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3967 3968 /* 3969 ** CAPI3REF: Name Of A Host Parameter 3970 ** METHOD: sqlite3_stmt 3971 ** 3972 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3973 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3974 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3975 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3976 ** respectively. 3977 ** In other words, the initial ":" or "$" or "@" or "?" 3978 ** is included as part of the name.)^ 3979 ** ^Parameters of the form "?" without a following integer have no name 3980 ** and are referred to as "nameless" or "anonymous parameters". 3981 ** 3982 ** ^The first host parameter has an index of 1, not 0. 3983 ** 3984 ** ^If the value N is out of range or if the N-th parameter is 3985 ** nameless, then NULL is returned. ^The returned string is 3986 ** always in UTF-8 encoding even if the named parameter was 3987 ** originally specified as UTF-16 in [sqlite3_prepare16()], 3988 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3989 ** 3990 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3991 ** [sqlite3_bind_parameter_count()], and 3992 ** [sqlite3_bind_parameter_index()]. 3993 */ 3994 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3995 3996 /* 3997 ** CAPI3REF: Index Of A Parameter With A Given Name 3998 ** METHOD: sqlite3_stmt 3999 ** 4000 ** ^Return the index of an SQL parameter given its name. ^The 4001 ** index value returned is suitable for use as the second 4002 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4003 ** is returned if no matching parameter is found. ^The parameter 4004 ** name must be given in UTF-8 even if the original statement 4005 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4006 ** [sqlite3_prepare16_v3()]. 4007 ** 4008 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4009 ** [sqlite3_bind_parameter_count()], and 4010 ** [sqlite3_bind_parameter_name()]. 4011 */ 4012 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4013 4014 /* 4015 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4016 ** METHOD: sqlite3_stmt 4017 ** 4018 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4019 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4020 ** ^Use this routine to reset all host parameters to NULL. 4021 */ 4022 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4023 4024 /* 4025 ** CAPI3REF: Number Of Columns In A Result Set 4026 ** METHOD: sqlite3_stmt 4027 ** 4028 ** ^Return the number of columns in the result set returned by the 4029 ** [prepared statement]. ^If this routine returns 0, that means the 4030 ** [prepared statement] returns no data (for example an [UPDATE]). 4031 ** ^However, just because this routine returns a positive number does not 4032 ** mean that one or more rows of data will be returned. ^A SELECT statement 4033 ** will always have a positive sqlite3_column_count() but depending on the 4034 ** WHERE clause constraints and the table content, it might return no rows. 4035 ** 4036 ** See also: [sqlite3_data_count()] 4037 */ 4038 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4039 4040 /* 4041 ** CAPI3REF: Column Names In A Result Set 4042 ** METHOD: sqlite3_stmt 4043 ** 4044 ** ^These routines return the name assigned to a particular column 4045 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4046 ** interface returns a pointer to a zero-terminated UTF-8 string 4047 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4048 ** UTF-16 string. ^The first parameter is the [prepared statement] 4049 ** that implements the [SELECT] statement. ^The second parameter is the 4050 ** column number. ^The leftmost column is number 0. 4051 ** 4052 ** ^The returned string pointer is valid until either the [prepared statement] 4053 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4054 ** reprepared by the first call to [sqlite3_step()] for a particular run 4055 ** or until the next call to 4056 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4057 ** 4058 ** ^If sqlite3_malloc() fails during the processing of either routine 4059 ** (for example during a conversion from UTF-8 to UTF-16) then a 4060 ** NULL pointer is returned. 4061 ** 4062 ** ^The name of a result column is the value of the "AS" clause for 4063 ** that column, if there is an AS clause. If there is no AS clause 4064 ** then the name of the column is unspecified and may change from 4065 ** one release of SQLite to the next. 4066 */ 4067 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4068 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4069 4070 /* 4071 ** CAPI3REF: Source Of Data In A Query Result 4072 ** METHOD: sqlite3_stmt 4073 ** 4074 ** ^These routines provide a means to determine the database, table, and 4075 ** table column that is the origin of a particular result column in 4076 ** [SELECT] statement. 4077 ** ^The name of the database or table or column can be returned as 4078 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4079 ** the database name, the _table_ routines return the table name, and 4080 ** the origin_ routines return the column name. 4081 ** ^The returned string is valid until the [prepared statement] is destroyed 4082 ** using [sqlite3_finalize()] or until the statement is automatically 4083 ** reprepared by the first call to [sqlite3_step()] for a particular run 4084 ** or until the same information is requested 4085 ** again in a different encoding. 4086 ** 4087 ** ^The names returned are the original un-aliased names of the 4088 ** database, table, and column. 4089 ** 4090 ** ^The first argument to these interfaces is a [prepared statement]. 4091 ** ^These functions return information about the Nth result column returned by 4092 ** the statement, where N is the second function argument. 4093 ** ^The left-most column is column 0 for these routines. 4094 ** 4095 ** ^If the Nth column returned by the statement is an expression or 4096 ** subquery and is not a column value, then all of these functions return 4097 ** NULL. ^These routine might also return NULL if a memory allocation error 4098 ** occurs. ^Otherwise, they return the name of the attached database, table, 4099 ** or column that query result column was extracted from. 4100 ** 4101 ** ^As with all other SQLite APIs, those whose names end with "16" return 4102 ** UTF-16 encoded strings and the other functions return UTF-8. 4103 ** 4104 ** ^These APIs are only available if the library was compiled with the 4105 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4106 ** 4107 ** If two or more threads call one or more of these routines against the same 4108 ** prepared statement and column at the same time then the results are 4109 ** undefined. 4110 ** 4111 ** If two or more threads call one or more 4112 ** [sqlite3_column_database_name | column metadata interfaces] 4113 ** for the same [prepared statement] and result column 4114 ** at the same time then the results are undefined. 4115 */ 4116 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4117 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4118 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4119 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4120 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4121 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4122 4123 /* 4124 ** CAPI3REF: Declared Datatype Of A Query Result 4125 ** METHOD: sqlite3_stmt 4126 ** 4127 ** ^(The first parameter is a [prepared statement]. 4128 ** If this statement is a [SELECT] statement and the Nth column of the 4129 ** returned result set of that [SELECT] is a table column (not an 4130 ** expression or subquery) then the declared type of the table 4131 ** column is returned.)^ ^If the Nth column of the result set is an 4132 ** expression or subquery, then a NULL pointer is returned. 4133 ** ^The returned string is always UTF-8 encoded. 4134 ** 4135 ** ^(For example, given the database schema: 4136 ** 4137 ** CREATE TABLE t1(c1 VARIANT); 4138 ** 4139 ** and the following statement to be compiled: 4140 ** 4141 ** SELECT c1 + 1, c1 FROM t1; 4142 ** 4143 ** this routine would return the string "VARIANT" for the second result 4144 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4145 ** 4146 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4147 ** is declared to contain a particular type does not mean that the 4148 ** data stored in that column is of the declared type. SQLite is 4149 ** strongly typed, but the typing is dynamic not static. ^Type 4150 ** is associated with individual values, not with the containers 4151 ** used to hold those values. 4152 */ 4153 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4154 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4155 4156 /* 4157 ** CAPI3REF: Evaluate An SQL Statement 4158 ** METHOD: sqlite3_stmt 4159 ** 4160 ** After a [prepared statement] has been prepared using any of 4161 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4162 ** or [sqlite3_prepare16_v3()] or one of the legacy 4163 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4164 ** must be called one or more times to evaluate the statement. 4165 ** 4166 ** The details of the behavior of the sqlite3_step() interface depend 4167 ** on whether the statement was prepared using the newer "vX" interfaces 4168 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4169 ** [sqlite3_prepare16_v2()] or the older legacy 4170 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4171 ** new "vX" interface is recommended for new applications but the legacy 4172 ** interface will continue to be supported. 4173 ** 4174 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4175 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4176 ** ^With the "v2" interface, any of the other [result codes] or 4177 ** [extended result codes] might be returned as well. 4178 ** 4179 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4180 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4181 ** or occurs outside of an explicit transaction, then you can retry the 4182 ** statement. If the statement is not a [COMMIT] and occurs within an 4183 ** explicit transaction then you should rollback the transaction before 4184 ** continuing. 4185 ** 4186 ** ^[SQLITE_DONE] means that the statement has finished executing 4187 ** successfully. sqlite3_step() should not be called again on this virtual 4188 ** machine without first calling [sqlite3_reset()] to reset the virtual 4189 ** machine back to its initial state. 4190 ** 4191 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4192 ** is returned each time a new row of data is ready for processing by the 4193 ** caller. The values may be accessed using the [column access functions]. 4194 ** sqlite3_step() is called again to retrieve the next row of data. 4195 ** 4196 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4197 ** violation) has occurred. sqlite3_step() should not be called again on 4198 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4199 ** ^With the legacy interface, a more specific error code (for example, 4200 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4201 ** can be obtained by calling [sqlite3_reset()] on the 4202 ** [prepared statement]. ^In the "v2" interface, 4203 ** the more specific error code is returned directly by sqlite3_step(). 4204 ** 4205 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4206 ** Perhaps it was called on a [prepared statement] that has 4207 ** already been [sqlite3_finalize | finalized] or on one that had 4208 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4209 ** be the case that the same database connection is being used by two or 4210 ** more threads at the same moment in time. 4211 ** 4212 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4213 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4214 ** other than [SQLITE_ROW] before any subsequent invocation of 4215 ** sqlite3_step(). Failure to reset the prepared statement using 4216 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4217 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4218 ** sqlite3_step() began 4219 ** calling [sqlite3_reset()] automatically in this circumstance rather 4220 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4221 ** break because any application that ever receives an SQLITE_MISUSE error 4222 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4223 ** can be used to restore the legacy behavior. 4224 ** 4225 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4226 ** API always returns a generic error code, [SQLITE_ERROR], following any 4227 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4228 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4229 ** specific [error codes] that better describes the error. 4230 ** We admit that this is a goofy design. The problem has been fixed 4231 ** with the "v2" interface. If you prepare all of your SQL statements 4232 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4233 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4234 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4235 ** then the more specific [error codes] are returned directly 4236 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4237 */ 4238 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4239 4240 /* 4241 ** CAPI3REF: Number of columns in a result set 4242 ** METHOD: sqlite3_stmt 4243 ** 4244 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4245 ** current row of the result set of [prepared statement] P. 4246 ** ^If prepared statement P does not have results ready to return 4247 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4248 ** interfaces) then sqlite3_data_count(P) returns 0. 4249 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4250 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4251 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4252 ** will return non-zero if previous call to [sqlite3_step](P) returned 4253 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4254 ** where it always returns zero since each step of that multi-step 4255 ** pragma returns 0 columns of data. 4256 ** 4257 ** See also: [sqlite3_column_count()] 4258 */ 4259 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4260 4261 /* 4262 ** CAPI3REF: Fundamental Datatypes 4263 ** KEYWORDS: SQLITE_TEXT 4264 ** 4265 ** ^(Every value in SQLite has one of five fundamental datatypes: 4266 ** 4267 ** <ul> 4268 ** <li> 64-bit signed integer 4269 ** <li> 64-bit IEEE floating point number 4270 ** <li> string 4271 ** <li> BLOB 4272 ** <li> NULL 4273 ** </ul>)^ 4274 ** 4275 ** These constants are codes for each of those types. 4276 ** 4277 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4278 ** for a completely different meaning. Software that links against both 4279 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4280 ** SQLITE_TEXT. 4281 */ 4282 #define SQLITE_INTEGER 1 4283 #define SQLITE_FLOAT 2 4284 #define SQLITE_BLOB 4 4285 #define SQLITE_NULL 5 4286 #ifdef SQLITE_TEXT 4287 # undef SQLITE_TEXT 4288 #else 4289 # define SQLITE_TEXT 3 4290 #endif 4291 #define SQLITE3_TEXT 3 4292 4293 /* 4294 ** CAPI3REF: Result Values From A Query 4295 ** KEYWORDS: {column access functions} 4296 ** METHOD: sqlite3_stmt 4297 ** 4298 ** <b>Summary:</b> 4299 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4300 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4301 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4302 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4303 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4304 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4305 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4306 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4307 ** [sqlite3_value|unprotected sqlite3_value] object. 4308 ** <tr><td> <td> <td> 4309 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4310 ** or a UTF-8 TEXT result in bytes 4311 ** <tr><td><b>sqlite3_column_bytes16 </b> 4312 ** <td>→ <td>Size of UTF-16 4313 ** TEXT in bytes 4314 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4315 ** datatype of the result 4316 ** </table></blockquote> 4317 ** 4318 ** <b>Details:</b> 4319 ** 4320 ** ^These routines return information about a single column of the current 4321 ** result row of a query. ^In every case the first argument is a pointer 4322 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4323 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4324 ** and the second argument is the index of the column for which information 4325 ** should be returned. ^The leftmost column of the result set has the index 0. 4326 ** ^The number of columns in the result can be determined using 4327 ** [sqlite3_column_count()]. 4328 ** 4329 ** If the SQL statement does not currently point to a valid row, or if the 4330 ** column index is out of range, the result is undefined. 4331 ** These routines may only be called when the most recent call to 4332 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4333 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4334 ** If any of these routines are called after [sqlite3_reset()] or 4335 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4336 ** something other than [SQLITE_ROW], the results are undefined. 4337 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4338 ** are called from a different thread while any of these routines 4339 ** are pending, then the results are undefined. 4340 ** 4341 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4342 ** each return the value of a result column in a specific data format. If 4343 ** the result column is not initially in the requested format (for example, 4344 ** if the query returns an integer but the sqlite3_column_text() interface 4345 ** is used to extract the value) then an automatic type conversion is performed. 4346 ** 4347 ** ^The sqlite3_column_type() routine returns the 4348 ** [SQLITE_INTEGER | datatype code] for the initial data type 4349 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4350 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4351 ** The return value of sqlite3_column_type() can be used to decide which 4352 ** of the first six interface should be used to extract the column value. 4353 ** The value returned by sqlite3_column_type() is only meaningful if no 4354 ** automatic type conversions have occurred for the value in question. 4355 ** After a type conversion, the result of calling sqlite3_column_type() 4356 ** is undefined, though harmless. Future 4357 ** versions of SQLite may change the behavior of sqlite3_column_type() 4358 ** following a type conversion. 4359 ** 4360 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4361 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4362 ** of that BLOB or string. 4363 ** 4364 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4365 ** routine returns the number of bytes in that BLOB or string. 4366 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4367 ** the string to UTF-8 and then returns the number of bytes. 4368 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4369 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4370 ** the number of bytes in that string. 4371 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4372 ** 4373 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4374 ** routine returns the number of bytes in that BLOB or string. 4375 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4376 ** the string to UTF-16 and then returns the number of bytes. 4377 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4378 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4379 ** the number of bytes in that string. 4380 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4381 ** 4382 ** ^The values returned by [sqlite3_column_bytes()] and 4383 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4384 ** of the string. ^For clarity: the values returned by 4385 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4386 ** bytes in the string, not the number of characters. 4387 ** 4388 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4389 ** even empty strings, are always zero-terminated. ^The return 4390 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4391 ** 4392 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4393 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4394 ** an unprotected sqlite3_value object may only be used safely with 4395 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4396 ** If the [unprotected sqlite3_value] object returned by 4397 ** [sqlite3_column_value()] is used in any other way, including calls 4398 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4399 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4400 ** Hence, the sqlite3_column_value() interface 4401 ** is normally only useful within the implementation of 4402 ** [application-defined SQL functions] or [virtual tables], not within 4403 ** top-level application code. 4404 ** 4405 ** The these routines may attempt to convert the datatype of the result. 4406 ** ^For example, if the internal representation is FLOAT and a text result 4407 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4408 ** conversion automatically. ^(The following table details the conversions 4409 ** that are applied: 4410 ** 4411 ** <blockquote> 4412 ** <table border="1"> 4413 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4414 ** 4415 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4416 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4417 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4418 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4419 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4420 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4421 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4422 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4423 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4424 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4425 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4426 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4427 ** <tr><td> TEXT <td> BLOB <td> No change 4428 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4429 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4430 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4431 ** </table> 4432 ** </blockquote>)^ 4433 ** 4434 ** Note that when type conversions occur, pointers returned by prior 4435 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4436 ** sqlite3_column_text16() may be invalidated. 4437 ** Type conversions and pointer invalidations might occur 4438 ** in the following cases: 4439 ** 4440 ** <ul> 4441 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4442 ** sqlite3_column_text16() is called. A zero-terminator might 4443 ** need to be added to the string.</li> 4444 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4445 ** sqlite3_column_text16() is called. The content must be converted 4446 ** to UTF-16.</li> 4447 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4448 ** sqlite3_column_text() is called. The content must be converted 4449 ** to UTF-8.</li> 4450 ** </ul> 4451 ** 4452 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4453 ** not invalidate a prior pointer, though of course the content of the buffer 4454 ** that the prior pointer references will have been modified. Other kinds 4455 ** of conversion are done in place when it is possible, but sometimes they 4456 ** are not possible and in those cases prior pointers are invalidated. 4457 ** 4458 ** The safest policy is to invoke these routines 4459 ** in one of the following ways: 4460 ** 4461 ** <ul> 4462 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4463 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4464 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4465 ** </ul> 4466 ** 4467 ** In other words, you should call sqlite3_column_text(), 4468 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4469 ** into the desired format, then invoke sqlite3_column_bytes() or 4470 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4471 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4472 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4473 ** with calls to sqlite3_column_bytes(). 4474 ** 4475 ** ^The pointers returned are valid until a type conversion occurs as 4476 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4477 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4478 ** and BLOBs is freed automatically. Do not pass the pointers returned 4479 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4480 ** [sqlite3_free()]. 4481 ** 4482 ** ^(If a memory allocation error occurs during the evaluation of any 4483 ** of these routines, a default value is returned. The default value 4484 ** is either the integer 0, the floating point number 0.0, or a NULL 4485 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4486 ** [SQLITE_NOMEM].)^ 4487 */ 4488 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4489 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4490 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4491 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4492 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4493 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4494 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4495 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4496 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4497 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4498 4499 /* 4500 ** CAPI3REF: Destroy A Prepared Statement Object 4501 ** DESTRUCTOR: sqlite3_stmt 4502 ** 4503 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4504 ** ^If the most recent evaluation of the statement encountered no errors 4505 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4506 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4507 ** sqlite3_finalize(S) returns the appropriate [error code] or 4508 ** [extended error code]. 4509 ** 4510 ** ^The sqlite3_finalize(S) routine can be called at any point during 4511 ** the life cycle of [prepared statement] S: 4512 ** before statement S is ever evaluated, after 4513 ** one or more calls to [sqlite3_reset()], or after any call 4514 ** to [sqlite3_step()] regardless of whether or not the statement has 4515 ** completed execution. 4516 ** 4517 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4518 ** 4519 ** The application must finalize every [prepared statement] in order to avoid 4520 ** resource leaks. It is a grievous error for the application to try to use 4521 ** a prepared statement after it has been finalized. Any use of a prepared 4522 ** statement after it has been finalized can result in undefined and 4523 ** undesirable behavior such as segfaults and heap corruption. 4524 */ 4525 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4526 4527 /* 4528 ** CAPI3REF: Reset A Prepared Statement Object 4529 ** METHOD: sqlite3_stmt 4530 ** 4531 ** The sqlite3_reset() function is called to reset a [prepared statement] 4532 ** object back to its initial state, ready to be re-executed. 4533 ** ^Any SQL statement variables that had values bound to them using 4534 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4535 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4536 ** 4537 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4538 ** back to the beginning of its program. 4539 ** 4540 ** ^If the most recent call to [sqlite3_step(S)] for the 4541 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4542 ** or if [sqlite3_step(S)] has never before been called on S, 4543 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4544 ** 4545 ** ^If the most recent call to [sqlite3_step(S)] for the 4546 ** [prepared statement] S indicated an error, then 4547 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4548 ** 4549 ** ^The [sqlite3_reset(S)] interface does not change the values 4550 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4551 */ 4552 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4553 4554 /* 4555 ** CAPI3REF: Create Or Redefine SQL Functions 4556 ** KEYWORDS: {function creation routines} 4557 ** KEYWORDS: {application-defined SQL function} 4558 ** KEYWORDS: {application-defined SQL functions} 4559 ** METHOD: sqlite3 4560 ** 4561 ** ^These functions (collectively known as "function creation routines") 4562 ** are used to add SQL functions or aggregates or to redefine the behavior 4563 ** of existing SQL functions or aggregates. The only differences between 4564 ** these routines are the text encoding expected for 4565 ** the second parameter (the name of the function being created) 4566 ** and the presence or absence of a destructor callback for 4567 ** the application data pointer. 4568 ** 4569 ** ^The first parameter is the [database connection] to which the SQL 4570 ** function is to be added. ^If an application uses more than one database 4571 ** connection then application-defined SQL functions must be added 4572 ** to each database connection separately. 4573 ** 4574 ** ^The second parameter is the name of the SQL function to be created or 4575 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4576 ** representation, exclusive of the zero-terminator. ^Note that the name 4577 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4578 ** ^Any attempt to create a function with a longer name 4579 ** will result in [SQLITE_MISUSE] being returned. 4580 ** 4581 ** ^The third parameter (nArg) 4582 ** is the number of arguments that the SQL function or 4583 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4584 ** aggregate may take any number of arguments between 0 and the limit 4585 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4586 ** parameter is less than -1 or greater than 127 then the behavior is 4587 ** undefined. 4588 ** 4589 ** ^The fourth parameter, eTextRep, specifies what 4590 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4591 ** its parameters. The application should set this parameter to 4592 ** [SQLITE_UTF16LE] if the function implementation invokes 4593 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4594 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4595 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4596 ** otherwise. ^The same SQL function may be registered multiple times using 4597 ** different preferred text encodings, with different implementations for 4598 ** each encoding. 4599 ** ^When multiple implementations of the same function are available, SQLite 4600 ** will pick the one that involves the least amount of data conversion. 4601 ** 4602 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4603 ** to signal that the function will always return the same result given 4604 ** the same inputs within a single SQL statement. Most SQL functions are 4605 ** deterministic. The built-in [random()] SQL function is an example of a 4606 ** function that is not deterministic. The SQLite query planner is able to 4607 ** perform additional optimizations on deterministic functions, so use 4608 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4609 ** 4610 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4611 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4612 ** 4613 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4614 ** pointers to C-language functions that implement the SQL function or 4615 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4616 ** callback only; NULL pointers must be passed as the xStep and xFinal 4617 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4618 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4619 ** SQL function or aggregate, pass NULL pointers for all three function 4620 ** callbacks. 4621 ** 4622 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4623 ** then it is destructor for the application data pointer. 4624 ** The destructor is invoked when the function is deleted, either by being 4625 ** overloaded or when the database connection closes.)^ 4626 ** ^The destructor is also invoked if the call to 4627 ** sqlite3_create_function_v2() fails. 4628 ** ^When the destructor callback of the tenth parameter is invoked, it 4629 ** is passed a single argument which is a copy of the application data 4630 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4631 ** 4632 ** ^It is permitted to register multiple implementations of the same 4633 ** functions with the same name but with either differing numbers of 4634 ** arguments or differing preferred text encodings. ^SQLite will use 4635 ** the implementation that most closely matches the way in which the 4636 ** SQL function is used. ^A function implementation with a non-negative 4637 ** nArg parameter is a better match than a function implementation with 4638 ** a negative nArg. ^A function where the preferred text encoding 4639 ** matches the database encoding is a better 4640 ** match than a function where the encoding is different. 4641 ** ^A function where the encoding difference is between UTF16le and UTF16be 4642 ** is a closer match than a function where the encoding difference is 4643 ** between UTF8 and UTF16. 4644 ** 4645 ** ^Built-in functions may be overloaded by new application-defined functions. 4646 ** 4647 ** ^An application-defined function is permitted to call other 4648 ** SQLite interfaces. However, such calls must not 4649 ** close the database connection nor finalize or reset the prepared 4650 ** statement in which the function is running. 4651 */ 4652 SQLITE_API int sqlite3_create_function( 4653 sqlite3 *db, 4654 const char *zFunctionName, 4655 int nArg, 4656 int eTextRep, 4657 void *pApp, 4658 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4659 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4660 void (*xFinal)(sqlite3_context*) 4661 ); 4662 SQLITE_API int sqlite3_create_function16( 4663 sqlite3 *db, 4664 const void *zFunctionName, 4665 int nArg, 4666 int eTextRep, 4667 void *pApp, 4668 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4669 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4670 void (*xFinal)(sqlite3_context*) 4671 ); 4672 SQLITE_API int sqlite3_create_function_v2( 4673 sqlite3 *db, 4674 const char *zFunctionName, 4675 int nArg, 4676 int eTextRep, 4677 void *pApp, 4678 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4679 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4680 void (*xFinal)(sqlite3_context*), 4681 void(*xDestroy)(void*) 4682 ); 4683 4684 /* 4685 ** CAPI3REF: Text Encodings 4686 ** 4687 ** These constant define integer codes that represent the various 4688 ** text encodings supported by SQLite. 4689 */ 4690 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4691 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4692 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4693 #define SQLITE_UTF16 4 /* Use native byte order */ 4694 #define SQLITE_ANY 5 /* Deprecated */ 4695 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4696 4697 /* 4698 ** CAPI3REF: Function Flags 4699 ** 4700 ** These constants may be ORed together with the 4701 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4702 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4703 ** [sqlite3_create_function_v2()]. 4704 */ 4705 #define SQLITE_DETERMINISTIC 0x800 4706 4707 /* 4708 ** CAPI3REF: Deprecated Functions 4709 ** DEPRECATED 4710 ** 4711 ** These functions are [deprecated]. In order to maintain 4712 ** backwards compatibility with older code, these functions continue 4713 ** to be supported. However, new applications should avoid 4714 ** the use of these functions. To encourage programmers to avoid 4715 ** these functions, we will not explain what they do. 4716 */ 4717 #ifndef SQLITE_OMIT_DEPRECATED 4718 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4719 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4720 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4721 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4722 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4723 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4724 void*,sqlite3_int64); 4725 #endif 4726 4727 /* 4728 ** CAPI3REF: Obtaining SQL Values 4729 ** METHOD: sqlite3_value 4730 ** 4731 ** <b>Summary:</b> 4732 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4733 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4734 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4735 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4736 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4737 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4738 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4739 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4740 ** the native byteorder 4741 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4742 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4743 ** <tr><td> <td> <td> 4744 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4745 ** or a UTF-8 TEXT in bytes 4746 ** <tr><td><b>sqlite3_value_bytes16 </b> 4747 ** <td>→ <td>Size of UTF-16 4748 ** TEXT in bytes 4749 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4750 ** datatype of the value 4751 ** <tr><td><b>sqlite3_value_numeric_type </b> 4752 ** <td>→ <td>Best numeric datatype of the value 4753 ** <tr><td><b>sqlite3_value_nochange </b> 4754 ** <td>→ <td>True if the column is unchanged in an UPDATE 4755 ** against a virtual table. 4756 ** </table></blockquote> 4757 ** 4758 ** <b>Details:</b> 4759 ** 4760 ** These routines extract type, size, and content information from 4761 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 4762 ** are used to pass parameter information into implementation of 4763 ** [application-defined SQL functions] and [virtual tables]. 4764 ** 4765 ** These routines work only with [protected sqlite3_value] objects. 4766 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4767 ** is not threadsafe. 4768 ** 4769 ** ^These routines work just like the corresponding [column access functions] 4770 ** except that these routines take a single [protected sqlite3_value] object 4771 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4772 ** 4773 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4774 ** in the native byte-order of the host machine. ^The 4775 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4776 ** extract UTF-16 strings as big-endian and little-endian respectively. 4777 ** 4778 ** ^If [sqlite3_value] object V was initialized 4779 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 4780 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 4781 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 4782 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 4783 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 4784 ** 4785 ** ^(The sqlite3_value_type(V) interface returns the 4786 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 4787 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 4788 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 4789 ** Other interfaces might change the datatype for an sqlite3_value object. 4790 ** For example, if the datatype is initially SQLITE_INTEGER and 4791 ** sqlite3_value_text(V) is called to extract a text value for that 4792 ** integer, then subsequent calls to sqlite3_value_type(V) might return 4793 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 4794 ** occurs is undefined and may change from one release of SQLite to the next. 4795 ** 4796 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4797 ** numeric affinity to the value. This means that an attempt is 4798 ** made to convert the value to an integer or floating point. If 4799 ** such a conversion is possible without loss of information (in other 4800 ** words, if the value is a string that looks like a number) 4801 ** then the conversion is performed. Otherwise no conversion occurs. 4802 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4803 ** 4804 ** ^Within the [xUpdate] method of a [virtual table], the 4805 ** sqlite3_value_nochange(X) interface returns true if and only if 4806 ** the column corresponding to X is unchanged by the UPDATE operation 4807 ** that the xUpdate method call was invoked to implement and if 4808 ** and the prior [xColumn] method call that was invoked to extracted 4809 ** the value for that column returned without setting a result (probably 4810 ** because it queried [sqlite3_vtab_nochange()] and found that the column 4811 ** was unchanging). ^Within an [xUpdate] method, any value for which 4812 ** sqlite3_value_nochange(X) is true will in all other respects appear 4813 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 4814 ** than within an [xUpdate] method call for an UPDATE statement, then 4815 ** the return value is arbitrary and meaningless. 4816 ** 4817 ** Please pay particular attention to the fact that the pointer returned 4818 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4819 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4820 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4821 ** or [sqlite3_value_text16()]. 4822 ** 4823 ** These routines must be called from the same thread as 4824 ** the SQL function that supplied the [sqlite3_value*] parameters. 4825 */ 4826 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4827 SQLITE_API double sqlite3_value_double(sqlite3_value*); 4828 SQLITE_API int sqlite3_value_int(sqlite3_value*); 4829 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4830 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 4831 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4832 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4833 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4834 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4835 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4836 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4837 SQLITE_API int sqlite3_value_type(sqlite3_value*); 4838 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4839 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 4840 4841 /* 4842 ** CAPI3REF: Finding The Subtype Of SQL Values 4843 ** METHOD: sqlite3_value 4844 ** 4845 ** The sqlite3_value_subtype(V) function returns the subtype for 4846 ** an [application-defined SQL function] argument V. The subtype 4847 ** information can be used to pass a limited amount of context from 4848 ** one SQL function to another. Use the [sqlite3_result_subtype()] 4849 ** routine to set the subtype for the return value of an SQL function. 4850 */ 4851 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 4852 4853 /* 4854 ** CAPI3REF: Copy And Free SQL Values 4855 ** METHOD: sqlite3_value 4856 ** 4857 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4858 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4859 ** is a [protected sqlite3_value] object even if the input is not. 4860 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4861 ** memory allocation fails. 4862 ** 4863 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4864 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4865 ** then sqlite3_value_free(V) is a harmless no-op. 4866 */ 4867 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4868 SQLITE_API void sqlite3_value_free(sqlite3_value*); 4869 4870 /* 4871 ** CAPI3REF: Obtain Aggregate Function Context 4872 ** METHOD: sqlite3_context 4873 ** 4874 ** Implementations of aggregate SQL functions use this 4875 ** routine to allocate memory for storing their state. 4876 ** 4877 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4878 ** for a particular aggregate function, SQLite 4879 ** allocates N of memory, zeroes out that memory, and returns a pointer 4880 ** to the new memory. ^On second and subsequent calls to 4881 ** sqlite3_aggregate_context() for the same aggregate function instance, 4882 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4883 ** called once for each invocation of the xStep callback and then one 4884 ** last time when the xFinal callback is invoked. ^(When no rows match 4885 ** an aggregate query, the xStep() callback of the aggregate function 4886 ** implementation is never called and xFinal() is called exactly once. 4887 ** In those cases, sqlite3_aggregate_context() might be called for the 4888 ** first time from within xFinal().)^ 4889 ** 4890 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4891 ** when first called if N is less than or equal to zero or if a memory 4892 ** allocate error occurs. 4893 ** 4894 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4895 ** determined by the N parameter on first successful call. Changing the 4896 ** value of N in subsequent call to sqlite3_aggregate_context() within 4897 ** the same aggregate function instance will not resize the memory 4898 ** allocation.)^ Within the xFinal callback, it is customary to set 4899 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4900 ** pointless memory allocations occur. 4901 ** 4902 ** ^SQLite automatically frees the memory allocated by 4903 ** sqlite3_aggregate_context() when the aggregate query concludes. 4904 ** 4905 ** The first parameter must be a copy of the 4906 ** [sqlite3_context | SQL function context] that is the first parameter 4907 ** to the xStep or xFinal callback routine that implements the aggregate 4908 ** function. 4909 ** 4910 ** This routine must be called from the same thread in which 4911 ** the aggregate SQL function is running. 4912 */ 4913 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4914 4915 /* 4916 ** CAPI3REF: User Data For Functions 4917 ** METHOD: sqlite3_context 4918 ** 4919 ** ^The sqlite3_user_data() interface returns a copy of 4920 ** the pointer that was the pUserData parameter (the 5th parameter) 4921 ** of the [sqlite3_create_function()] 4922 ** and [sqlite3_create_function16()] routines that originally 4923 ** registered the application defined function. 4924 ** 4925 ** This routine must be called from the same thread in which 4926 ** the application-defined function is running. 4927 */ 4928 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4929 4930 /* 4931 ** CAPI3REF: Database Connection For Functions 4932 ** METHOD: sqlite3_context 4933 ** 4934 ** ^The sqlite3_context_db_handle() interface returns a copy of 4935 ** the pointer to the [database connection] (the 1st parameter) 4936 ** of the [sqlite3_create_function()] 4937 ** and [sqlite3_create_function16()] routines that originally 4938 ** registered the application defined function. 4939 */ 4940 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4941 4942 /* 4943 ** CAPI3REF: Function Auxiliary Data 4944 ** METHOD: sqlite3_context 4945 ** 4946 ** These functions may be used by (non-aggregate) SQL functions to 4947 ** associate metadata with argument values. If the same value is passed to 4948 ** multiple invocations of the same SQL function during query execution, under 4949 ** some circumstances the associated metadata may be preserved. An example 4950 ** of where this might be useful is in a regular-expression matching 4951 ** function. The compiled version of the regular expression can be stored as 4952 ** metadata associated with the pattern string. 4953 ** Then as long as the pattern string remains the same, 4954 ** the compiled regular expression can be reused on multiple 4955 ** invocations of the same function. 4956 ** 4957 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 4958 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 4959 ** value to the application-defined function. ^N is zero for the left-most 4960 ** function argument. ^If there is no metadata 4961 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 4962 ** returns a NULL pointer. 4963 ** 4964 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4965 ** argument of the application-defined function. ^Subsequent 4966 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4967 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4968 ** NULL if the metadata has been discarded. 4969 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4970 ** SQLite will invoke the destructor function X with parameter P exactly 4971 ** once, when the metadata is discarded. 4972 ** SQLite is free to discard the metadata at any time, including: <ul> 4973 ** <li> ^(when the corresponding function parameter changes)^, or 4974 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4975 ** SQL statement)^, or 4976 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4977 ** parameter)^, or 4978 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4979 ** allocation error occurs.)^ </ul> 4980 ** 4981 ** Note the last bullet in particular. The destructor X in 4982 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4983 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4984 ** should be called near the end of the function implementation and the 4985 ** function implementation should not make any use of P after 4986 ** sqlite3_set_auxdata() has been called. 4987 ** 4988 ** ^(In practice, metadata is preserved between function calls for 4989 ** function parameters that are compile-time constants, including literal 4990 ** values and [parameters] and expressions composed from the same.)^ 4991 ** 4992 ** The value of the N parameter to these interfaces should be non-negative. 4993 ** Future enhancements may make use of negative N values to define new 4994 ** kinds of function caching behavior. 4995 ** 4996 ** These routines must be called from the same thread in which 4997 ** the SQL function is running. 4998 */ 4999 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5000 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5001 5002 5003 /* 5004 ** CAPI3REF: Constants Defining Special Destructor Behavior 5005 ** 5006 ** These are special values for the destructor that is passed in as the 5007 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5008 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5009 ** and will never change. It does not need to be destroyed. ^The 5010 ** SQLITE_TRANSIENT value means that the content will likely change in 5011 ** the near future and that SQLite should make its own private copy of 5012 ** the content before returning. 5013 ** 5014 ** The typedef is necessary to work around problems in certain 5015 ** C++ compilers. 5016 */ 5017 typedef void (*sqlite3_destructor_type)(void*); 5018 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5019 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5020 5021 /* 5022 ** CAPI3REF: Setting The Result Of An SQL Function 5023 ** METHOD: sqlite3_context 5024 ** 5025 ** These routines are used by the xFunc or xFinal callbacks that 5026 ** implement SQL functions and aggregates. See 5027 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5028 ** for additional information. 5029 ** 5030 ** These functions work very much like the [parameter binding] family of 5031 ** functions used to bind values to host parameters in prepared statements. 5032 ** Refer to the [SQL parameter] documentation for additional information. 5033 ** 5034 ** ^The sqlite3_result_blob() interface sets the result from 5035 ** an application-defined function to be the BLOB whose content is pointed 5036 ** to by the second parameter and which is N bytes long where N is the 5037 ** third parameter. 5038 ** 5039 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5040 ** interfaces set the result of the application-defined function to be 5041 ** a BLOB containing all zero bytes and N bytes in size. 5042 ** 5043 ** ^The sqlite3_result_double() interface sets the result from 5044 ** an application-defined function to be a floating point value specified 5045 ** by its 2nd argument. 5046 ** 5047 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5048 ** cause the implemented SQL function to throw an exception. 5049 ** ^SQLite uses the string pointed to by the 5050 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5051 ** as the text of an error message. ^SQLite interprets the error 5052 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5053 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 5054 ** byte order. ^If the third parameter to sqlite3_result_error() 5055 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5056 ** message all text up through the first zero character. 5057 ** ^If the third parameter to sqlite3_result_error() or 5058 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5059 ** bytes (not characters) from the 2nd parameter as the error message. 5060 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5061 ** routines make a private copy of the error message text before 5062 ** they return. Hence, the calling function can deallocate or 5063 ** modify the text after they return without harm. 5064 ** ^The sqlite3_result_error_code() function changes the error code 5065 ** returned by SQLite as a result of an error in a function. ^By default, 5066 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5067 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5068 ** 5069 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5070 ** error indicating that a string or BLOB is too long to represent. 5071 ** 5072 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5073 ** error indicating that a memory allocation failed. 5074 ** 5075 ** ^The sqlite3_result_int() interface sets the return value 5076 ** of the application-defined function to be the 32-bit signed integer 5077 ** value given in the 2nd argument. 5078 ** ^The sqlite3_result_int64() interface sets the return value 5079 ** of the application-defined function to be the 64-bit signed integer 5080 ** value given in the 2nd argument. 5081 ** 5082 ** ^The sqlite3_result_null() interface sets the return value 5083 ** of the application-defined function to be NULL. 5084 ** 5085 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5086 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5087 ** set the return value of the application-defined function to be 5088 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5089 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5090 ** ^The sqlite3_result_text64() interface sets the return value of an 5091 ** application-defined function to be a text string in an encoding 5092 ** specified by the fifth (and last) parameter, which must be one 5093 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5094 ** ^SQLite takes the text result from the application from 5095 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5096 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5097 ** is negative, then SQLite takes result text from the 2nd parameter 5098 ** through the first zero character. 5099 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5100 ** is non-negative, then as many bytes (not characters) of the text 5101 ** pointed to by the 2nd parameter are taken as the application-defined 5102 ** function result. If the 3rd parameter is non-negative, then it 5103 ** must be the byte offset into the string where the NUL terminator would 5104 ** appear if the string where NUL terminated. If any NUL characters occur 5105 ** in the string at a byte offset that is less than the value of the 3rd 5106 ** parameter, then the resulting string will contain embedded NULs and the 5107 ** result of expressions operating on strings with embedded NULs is undefined. 5108 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5109 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5110 ** function as the destructor on the text or BLOB result when it has 5111 ** finished using that result. 5112 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5113 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5114 ** assumes that the text or BLOB result is in constant space and does not 5115 ** copy the content of the parameter nor call a destructor on the content 5116 ** when it has finished using that result. 5117 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5118 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5119 ** then SQLite makes a copy of the result into space obtained 5120 ** from [sqlite3_malloc()] before it returns. 5121 ** 5122 ** ^The sqlite3_result_value() interface sets the result of 5123 ** the application-defined function to be a copy of the 5124 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5125 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5126 ** so that the [sqlite3_value] specified in the parameter may change or 5127 ** be deallocated after sqlite3_result_value() returns without harm. 5128 ** ^A [protected sqlite3_value] object may always be used where an 5129 ** [unprotected sqlite3_value] object is required, so either 5130 ** kind of [sqlite3_value] object can be used with this interface. 5131 ** 5132 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5133 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5134 ** also associates the host-language pointer P or type T with that 5135 ** NULL value such that the pointer can be retrieved within an 5136 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5137 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5138 ** for the P parameter. ^SQLite invokes D with P as its only argument 5139 ** when SQLite is finished with P. The T parameter should be a static 5140 ** string and preferably a string literal. The sqlite3_result_pointer() 5141 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5142 ** 5143 ** If these routines are called from within the different thread 5144 ** than the one containing the application-defined function that received 5145 ** the [sqlite3_context] pointer, the results are undefined. 5146 */ 5147 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5148 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5149 sqlite3_uint64,void(*)(void*)); 5150 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5151 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5152 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5153 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5154 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5155 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5156 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5157 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5158 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5159 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5160 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5161 void(*)(void*), unsigned char encoding); 5162 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5163 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5164 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5165 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5166 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5167 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5168 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5169 5170 5171 /* 5172 ** CAPI3REF: Setting The Subtype Of An SQL Function 5173 ** METHOD: sqlite3_context 5174 ** 5175 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5176 ** the result from the [application-defined SQL function] with 5177 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5178 ** of the subtype T are preserved in current versions of SQLite; 5179 ** higher order bits are discarded. 5180 ** The number of subtype bytes preserved by SQLite might increase 5181 ** in future releases of SQLite. 5182 */ 5183 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5184 5185 /* 5186 ** CAPI3REF: Define New Collating Sequences 5187 ** METHOD: sqlite3 5188 ** 5189 ** ^These functions add, remove, or modify a [collation] associated 5190 ** with the [database connection] specified as the first argument. 5191 ** 5192 ** ^The name of the collation is a UTF-8 string 5193 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5194 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5195 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5196 ** considered to be the same name. 5197 ** 5198 ** ^(The third argument (eTextRep) must be one of the constants: 5199 ** <ul> 5200 ** <li> [SQLITE_UTF8], 5201 ** <li> [SQLITE_UTF16LE], 5202 ** <li> [SQLITE_UTF16BE], 5203 ** <li> [SQLITE_UTF16], or 5204 ** <li> [SQLITE_UTF16_ALIGNED]. 5205 ** </ul>)^ 5206 ** ^The eTextRep argument determines the encoding of strings passed 5207 ** to the collating function callback, xCallback. 5208 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5209 ** force strings to be UTF16 with native byte order. 5210 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5211 ** on an even byte address. 5212 ** 5213 ** ^The fourth argument, pArg, is an application data pointer that is passed 5214 ** through as the first argument to the collating function callback. 5215 ** 5216 ** ^The fifth argument, xCallback, is a pointer to the collating function. 5217 ** ^Multiple collating functions can be registered using the same name but 5218 ** with different eTextRep parameters and SQLite will use whichever 5219 ** function requires the least amount of data transformation. 5220 ** ^If the xCallback argument is NULL then the collating function is 5221 ** deleted. ^When all collating functions having the same name are deleted, 5222 ** that collation is no longer usable. 5223 ** 5224 ** ^The collating function callback is invoked with a copy of the pArg 5225 ** application data pointer and with two strings in the encoding specified 5226 ** by the eTextRep argument. The collating function must return an 5227 ** integer that is negative, zero, or positive 5228 ** if the first string is less than, equal to, or greater than the second, 5229 ** respectively. A collating function must always return the same answer 5230 ** given the same inputs. If two or more collating functions are registered 5231 ** to the same collation name (using different eTextRep values) then all 5232 ** must give an equivalent answer when invoked with equivalent strings. 5233 ** The collating function must obey the following properties for all 5234 ** strings A, B, and C: 5235 ** 5236 ** <ol> 5237 ** <li> If A==B then B==A. 5238 ** <li> If A==B and B==C then A==C. 5239 ** <li> If A<B THEN B>A. 5240 ** <li> If A<B and B<C then A<C. 5241 ** </ol> 5242 ** 5243 ** If a collating function fails any of the above constraints and that 5244 ** collating function is registered and used, then the behavior of SQLite 5245 ** is undefined. 5246 ** 5247 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5248 ** with the addition that the xDestroy callback is invoked on pArg when 5249 ** the collating function is deleted. 5250 ** ^Collating functions are deleted when they are overridden by later 5251 ** calls to the collation creation functions or when the 5252 ** [database connection] is closed using [sqlite3_close()]. 5253 ** 5254 ** ^The xDestroy callback is <u>not</u> called if the 5255 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5256 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5257 ** check the return code and dispose of the application data pointer 5258 ** themselves rather than expecting SQLite to deal with it for them. 5259 ** This is different from every other SQLite interface. The inconsistency 5260 ** is unfortunate but cannot be changed without breaking backwards 5261 ** compatibility. 5262 ** 5263 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5264 */ 5265 SQLITE_API int sqlite3_create_collation( 5266 sqlite3*, 5267 const char *zName, 5268 int eTextRep, 5269 void *pArg, 5270 int(*xCompare)(void*,int,const void*,int,const void*) 5271 ); 5272 SQLITE_API int sqlite3_create_collation_v2( 5273 sqlite3*, 5274 const char *zName, 5275 int eTextRep, 5276 void *pArg, 5277 int(*xCompare)(void*,int,const void*,int,const void*), 5278 void(*xDestroy)(void*) 5279 ); 5280 SQLITE_API int sqlite3_create_collation16( 5281 sqlite3*, 5282 const void *zName, 5283 int eTextRep, 5284 void *pArg, 5285 int(*xCompare)(void*,int,const void*,int,const void*) 5286 ); 5287 5288 /* 5289 ** CAPI3REF: Collation Needed Callbacks 5290 ** METHOD: sqlite3 5291 ** 5292 ** ^To avoid having to register all collation sequences before a database 5293 ** can be used, a single callback function may be registered with the 5294 ** [database connection] to be invoked whenever an undefined collation 5295 ** sequence is required. 5296 ** 5297 ** ^If the function is registered using the sqlite3_collation_needed() API, 5298 ** then it is passed the names of undefined collation sequences as strings 5299 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5300 ** the names are passed as UTF-16 in machine native byte order. 5301 ** ^A call to either function replaces the existing collation-needed callback. 5302 ** 5303 ** ^(When the callback is invoked, the first argument passed is a copy 5304 ** of the second argument to sqlite3_collation_needed() or 5305 ** sqlite3_collation_needed16(). The second argument is the database 5306 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5307 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5308 ** sequence function required. The fourth parameter is the name of the 5309 ** required collation sequence.)^ 5310 ** 5311 ** The callback function should register the desired collation using 5312 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5313 ** [sqlite3_create_collation_v2()]. 5314 */ 5315 SQLITE_API int sqlite3_collation_needed( 5316 sqlite3*, 5317 void*, 5318 void(*)(void*,sqlite3*,int eTextRep,const char*) 5319 ); 5320 SQLITE_API int sqlite3_collation_needed16( 5321 sqlite3*, 5322 void*, 5323 void(*)(void*,sqlite3*,int eTextRep,const void*) 5324 ); 5325 5326 #ifdef SQLITE_HAS_CODEC 5327 /* 5328 ** Specify the key for an encrypted database. This routine should be 5329 ** called right after sqlite3_open(). 5330 ** 5331 ** The code to implement this API is not available in the public release 5332 ** of SQLite. 5333 */ 5334 SQLITE_API int sqlite3_key( 5335 sqlite3 *db, /* Database to be rekeyed */ 5336 const void *pKey, int nKey /* The key */ 5337 ); 5338 SQLITE_API int sqlite3_key_v2( 5339 sqlite3 *db, /* Database to be rekeyed */ 5340 const char *zDbName, /* Name of the database */ 5341 const void *pKey, int nKey /* The key */ 5342 ); 5343 5344 /* 5345 ** Change the key on an open database. If the current database is not 5346 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5347 ** database is decrypted. 5348 ** 5349 ** The code to implement this API is not available in the public release 5350 ** of SQLite. 5351 */ 5352 SQLITE_API int sqlite3_rekey( 5353 sqlite3 *db, /* Database to be rekeyed */ 5354 const void *pKey, int nKey /* The new key */ 5355 ); 5356 SQLITE_API int sqlite3_rekey_v2( 5357 sqlite3 *db, /* Database to be rekeyed */ 5358 const char *zDbName, /* Name of the database */ 5359 const void *pKey, int nKey /* The new key */ 5360 ); 5361 5362 /* 5363 ** Specify the activation key for a SEE database. Unless 5364 ** activated, none of the SEE routines will work. 5365 */ 5366 SQLITE_API void sqlite3_activate_see( 5367 const char *zPassPhrase /* Activation phrase */ 5368 ); 5369 #endif 5370 5371 #ifdef SQLITE_ENABLE_CEROD 5372 /* 5373 ** Specify the activation key for a CEROD database. Unless 5374 ** activated, none of the CEROD routines will work. 5375 */ 5376 SQLITE_API void sqlite3_activate_cerod( 5377 const char *zPassPhrase /* Activation phrase */ 5378 ); 5379 #endif 5380 5381 /* 5382 ** CAPI3REF: Suspend Execution For A Short Time 5383 ** 5384 ** The sqlite3_sleep() function causes the current thread to suspend execution 5385 ** for at least a number of milliseconds specified in its parameter. 5386 ** 5387 ** If the operating system does not support sleep requests with 5388 ** millisecond time resolution, then the time will be rounded up to 5389 ** the nearest second. The number of milliseconds of sleep actually 5390 ** requested from the operating system is returned. 5391 ** 5392 ** ^SQLite implements this interface by calling the xSleep() 5393 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5394 ** of the default VFS is not implemented correctly, or not implemented at 5395 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5396 ** in the previous paragraphs. 5397 */ 5398 SQLITE_API int sqlite3_sleep(int); 5399 5400 /* 5401 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5402 ** 5403 ** ^(If this global variable is made to point to a string which is 5404 ** the name of a folder (a.k.a. directory), then all temporary files 5405 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5406 ** will be placed in that directory.)^ ^If this variable 5407 ** is a NULL pointer, then SQLite performs a search for an appropriate 5408 ** temporary file directory. 5409 ** 5410 ** Applications are strongly discouraged from using this global variable. 5411 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5412 ** But for all other platforms, it is highly recommended that applications 5413 ** neither read nor write this variable. This global variable is a relic 5414 ** that exists for backwards compatibility of legacy applications and should 5415 ** be avoided in new projects. 5416 ** 5417 ** It is not safe to read or modify this variable in more than one 5418 ** thread at a time. It is not safe to read or modify this variable 5419 ** if a [database connection] is being used at the same time in a separate 5420 ** thread. 5421 ** It is intended that this variable be set once 5422 ** as part of process initialization and before any SQLite interface 5423 ** routines have been called and that this variable remain unchanged 5424 ** thereafter. 5425 ** 5426 ** ^The [temp_store_directory pragma] may modify this variable and cause 5427 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5428 ** the [temp_store_directory pragma] always assumes that any string 5429 ** that this variable points to is held in memory obtained from 5430 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5431 ** using [sqlite3_free]. 5432 ** Hence, if this variable is modified directly, either it should be 5433 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5434 ** or else the use of the [temp_store_directory pragma] should be avoided. 5435 ** Except when requested by the [temp_store_directory pragma], SQLite 5436 ** does not free the memory that sqlite3_temp_directory points to. If 5437 ** the application wants that memory to be freed, it must do 5438 ** so itself, taking care to only do so after all [database connection] 5439 ** objects have been destroyed. 5440 ** 5441 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5442 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5443 ** features that require the use of temporary files may fail. Here is an 5444 ** example of how to do this using C++ with the Windows Runtime: 5445 ** 5446 ** <blockquote><pre> 5447 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5448 ** TemporaryFolder->Path->Data(); 5449 ** char zPathBuf[MAX_PATH + 1]; 5450 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5451 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5452 ** NULL, NULL); 5453 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5454 ** </pre></blockquote> 5455 */ 5456 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5457 5458 /* 5459 ** CAPI3REF: Name Of The Folder Holding Database Files 5460 ** 5461 ** ^(If this global variable is made to point to a string which is 5462 ** the name of a folder (a.k.a. directory), then all database files 5463 ** specified with a relative pathname and created or accessed by 5464 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5465 ** to be relative to that directory.)^ ^If this variable is a NULL 5466 ** pointer, then SQLite assumes that all database files specified 5467 ** with a relative pathname are relative to the current directory 5468 ** for the process. Only the windows VFS makes use of this global 5469 ** variable; it is ignored by the unix VFS. 5470 ** 5471 ** Changing the value of this variable while a database connection is 5472 ** open can result in a corrupt database. 5473 ** 5474 ** It is not safe to read or modify this variable in more than one 5475 ** thread at a time. It is not safe to read or modify this variable 5476 ** if a [database connection] is being used at the same time in a separate 5477 ** thread. 5478 ** It is intended that this variable be set once 5479 ** as part of process initialization and before any SQLite interface 5480 ** routines have been called and that this variable remain unchanged 5481 ** thereafter. 5482 ** 5483 ** ^The [data_store_directory pragma] may modify this variable and cause 5484 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5485 ** the [data_store_directory pragma] always assumes that any string 5486 ** that this variable points to is held in memory obtained from 5487 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5488 ** using [sqlite3_free]. 5489 ** Hence, if this variable is modified directly, either it should be 5490 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5491 ** or else the use of the [data_store_directory pragma] should be avoided. 5492 */ 5493 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5494 5495 /* 5496 ** CAPI3REF: Test For Auto-Commit Mode 5497 ** KEYWORDS: {autocommit mode} 5498 ** METHOD: sqlite3 5499 ** 5500 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5501 ** zero if the given database connection is or is not in autocommit mode, 5502 ** respectively. ^Autocommit mode is on by default. 5503 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5504 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5505 ** 5506 ** If certain kinds of errors occur on a statement within a multi-statement 5507 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5508 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5509 ** transaction might be rolled back automatically. The only way to 5510 ** find out whether SQLite automatically rolled back the transaction after 5511 ** an error is to use this function. 5512 ** 5513 ** If another thread changes the autocommit status of the database 5514 ** connection while this routine is running, then the return value 5515 ** is undefined. 5516 */ 5517 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5518 5519 /* 5520 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5521 ** METHOD: sqlite3_stmt 5522 ** 5523 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5524 ** to which a [prepared statement] belongs. ^The [database connection] 5525 ** returned by sqlite3_db_handle is the same [database connection] 5526 ** that was the first argument 5527 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5528 ** create the statement in the first place. 5529 */ 5530 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5531 5532 /* 5533 ** CAPI3REF: Return The Filename For A Database Connection 5534 ** METHOD: sqlite3 5535 ** 5536 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5537 ** associated with database N of connection D. ^The main database file 5538 ** has the name "main". If there is no attached database N on the database 5539 ** connection D, or if database N is a temporary or in-memory database, then 5540 ** a NULL pointer is returned. 5541 ** 5542 ** ^The filename returned by this function is the output of the 5543 ** xFullPathname method of the [VFS]. ^In other words, the filename 5544 ** will be an absolute pathname, even if the filename used 5545 ** to open the database originally was a URI or relative pathname. 5546 */ 5547 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5548 5549 /* 5550 ** CAPI3REF: Determine if a database is read-only 5551 ** METHOD: sqlite3 5552 ** 5553 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5554 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5555 ** the name of a database on connection D. 5556 */ 5557 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5558 5559 /* 5560 ** CAPI3REF: Find the next prepared statement 5561 ** METHOD: sqlite3 5562 ** 5563 ** ^This interface returns a pointer to the next [prepared statement] after 5564 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5565 ** then this interface returns a pointer to the first prepared statement 5566 ** associated with the database connection pDb. ^If no prepared statement 5567 ** satisfies the conditions of this routine, it returns NULL. 5568 ** 5569 ** The [database connection] pointer D in a call to 5570 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5571 ** connection and in particular must not be a NULL pointer. 5572 */ 5573 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5574 5575 /* 5576 ** CAPI3REF: Commit And Rollback Notification Callbacks 5577 ** METHOD: sqlite3 5578 ** 5579 ** ^The sqlite3_commit_hook() interface registers a callback 5580 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5581 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5582 ** for the same database connection is overridden. 5583 ** ^The sqlite3_rollback_hook() interface registers a callback 5584 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5585 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5586 ** for the same database connection is overridden. 5587 ** ^The pArg argument is passed through to the callback. 5588 ** ^If the callback on a commit hook function returns non-zero, 5589 ** then the commit is converted into a rollback. 5590 ** 5591 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5592 ** return the P argument from the previous call of the same function 5593 ** on the same [database connection] D, or NULL for 5594 ** the first call for each function on D. 5595 ** 5596 ** The commit and rollback hook callbacks are not reentrant. 5597 ** The callback implementation must not do anything that will modify 5598 ** the database connection that invoked the callback. Any actions 5599 ** to modify the database connection must be deferred until after the 5600 ** completion of the [sqlite3_step()] call that triggered the commit 5601 ** or rollback hook in the first place. 5602 ** Note that running any other SQL statements, including SELECT statements, 5603 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5604 ** the database connections for the meaning of "modify" in this paragraph. 5605 ** 5606 ** ^Registering a NULL function disables the callback. 5607 ** 5608 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5609 ** operation is allowed to continue normally. ^If the commit hook 5610 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5611 ** ^The rollback hook is invoked on a rollback that results from a commit 5612 ** hook returning non-zero, just as it would be with any other rollback. 5613 ** 5614 ** ^For the purposes of this API, a transaction is said to have been 5615 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5616 ** an error or constraint causes an implicit rollback to occur. 5617 ** ^The rollback callback is not invoked if a transaction is 5618 ** automatically rolled back because the database connection is closed. 5619 ** 5620 ** See also the [sqlite3_update_hook()] interface. 5621 */ 5622 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5623 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5624 5625 /* 5626 ** CAPI3REF: Data Change Notification Callbacks 5627 ** METHOD: sqlite3 5628 ** 5629 ** ^The sqlite3_update_hook() interface registers a callback function 5630 ** with the [database connection] identified by the first argument 5631 ** to be invoked whenever a row is updated, inserted or deleted in 5632 ** a [rowid table]. 5633 ** ^Any callback set by a previous call to this function 5634 ** for the same database connection is overridden. 5635 ** 5636 ** ^The second argument is a pointer to the function to invoke when a 5637 ** row is updated, inserted or deleted in a rowid table. 5638 ** ^The first argument to the callback is a copy of the third argument 5639 ** to sqlite3_update_hook(). 5640 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5641 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5642 ** to be invoked. 5643 ** ^The third and fourth arguments to the callback contain pointers to the 5644 ** database and table name containing the affected row. 5645 ** ^The final callback parameter is the [rowid] of the row. 5646 ** ^In the case of an update, this is the [rowid] after the update takes place. 5647 ** 5648 ** ^(The update hook is not invoked when internal system tables are 5649 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5650 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5651 ** 5652 ** ^In the current implementation, the update hook 5653 ** is not invoked when conflicting rows are deleted because of an 5654 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5655 ** invoked when rows are deleted using the [truncate optimization]. 5656 ** The exceptions defined in this paragraph might change in a future 5657 ** release of SQLite. 5658 ** 5659 ** The update hook implementation must not do anything that will modify 5660 ** the database connection that invoked the update hook. Any actions 5661 ** to modify the database connection must be deferred until after the 5662 ** completion of the [sqlite3_step()] call that triggered the update hook. 5663 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5664 ** database connections for the meaning of "modify" in this paragraph. 5665 ** 5666 ** ^The sqlite3_update_hook(D,C,P) function 5667 ** returns the P argument from the previous call 5668 ** on the same [database connection] D, or NULL for 5669 ** the first call on D. 5670 ** 5671 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5672 ** and [sqlite3_preupdate_hook()] interfaces. 5673 */ 5674 SQLITE_API void *sqlite3_update_hook( 5675 sqlite3*, 5676 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5677 void* 5678 ); 5679 5680 /* 5681 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5682 ** 5683 ** ^(This routine enables or disables the sharing of the database cache 5684 ** and schema data structures between [database connection | connections] 5685 ** to the same database. Sharing is enabled if the argument is true 5686 ** and disabled if the argument is false.)^ 5687 ** 5688 ** ^Cache sharing is enabled and disabled for an entire process. 5689 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5690 ** In prior versions of SQLite, 5691 ** sharing was enabled or disabled for each thread separately. 5692 ** 5693 ** ^(The cache sharing mode set by this interface effects all subsequent 5694 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5695 ** Existing database connections continue use the sharing mode 5696 ** that was in effect at the time they were opened.)^ 5697 ** 5698 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5699 ** successfully. An [error code] is returned otherwise.)^ 5700 ** 5701 ** ^Shared cache is disabled by default. But this might change in 5702 ** future releases of SQLite. Applications that care about shared 5703 ** cache setting should set it explicitly. 5704 ** 5705 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5706 ** and will always return SQLITE_MISUSE. On those systems, 5707 ** shared cache mode should be enabled per-database connection via 5708 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5709 ** 5710 ** This interface is threadsafe on processors where writing a 5711 ** 32-bit integer is atomic. 5712 ** 5713 ** See Also: [SQLite Shared-Cache Mode] 5714 */ 5715 SQLITE_API int sqlite3_enable_shared_cache(int); 5716 5717 /* 5718 ** CAPI3REF: Attempt To Free Heap Memory 5719 ** 5720 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5721 ** of heap memory by deallocating non-essential memory allocations 5722 ** held by the database library. Memory used to cache database 5723 ** pages to improve performance is an example of non-essential memory. 5724 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5725 ** which might be more or less than the amount requested. 5726 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5727 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5728 ** 5729 ** See also: [sqlite3_db_release_memory()] 5730 */ 5731 SQLITE_API int sqlite3_release_memory(int); 5732 5733 /* 5734 ** CAPI3REF: Free Memory Used By A Database Connection 5735 ** METHOD: sqlite3 5736 ** 5737 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5738 ** memory as possible from database connection D. Unlike the 5739 ** [sqlite3_release_memory()] interface, this interface is in effect even 5740 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5741 ** omitted. 5742 ** 5743 ** See also: [sqlite3_release_memory()] 5744 */ 5745 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5746 5747 /* 5748 ** CAPI3REF: Impose A Limit On Heap Size 5749 ** 5750 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5751 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5752 ** ^SQLite strives to keep heap memory utilization below the soft heap 5753 ** limit by reducing the number of pages held in the page cache 5754 ** as heap memory usages approaches the limit. 5755 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5756 ** below the limit, it will exceed the limit rather than generate 5757 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5758 ** is advisory only. 5759 ** 5760 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5761 ** the soft heap limit prior to the call, or negative in the case of an 5762 ** error. ^If the argument N is negative 5763 ** then no change is made to the soft heap limit. Hence, the current 5764 ** size of the soft heap limit can be determined by invoking 5765 ** sqlite3_soft_heap_limit64() with a negative argument. 5766 ** 5767 ** ^If the argument N is zero then the soft heap limit is disabled. 5768 ** 5769 ** ^(The soft heap limit is not enforced in the current implementation 5770 ** if one or more of following conditions are true: 5771 ** 5772 ** <ul> 5773 ** <li> The soft heap limit is set to zero. 5774 ** <li> Memory accounting is disabled using a combination of the 5775 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5776 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5777 ** <li> An alternative page cache implementation is specified using 5778 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5779 ** <li> The page cache allocates from its own memory pool supplied 5780 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5781 ** from the heap. 5782 ** </ul>)^ 5783 ** 5784 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5785 ** the soft heap limit is enforced 5786 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5787 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5788 ** the soft heap limit is enforced on every memory allocation. Without 5789 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5790 ** when memory is allocated by the page cache. Testing suggests that because 5791 ** the page cache is the predominate memory user in SQLite, most 5792 ** applications will achieve adequate soft heap limit enforcement without 5793 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5794 ** 5795 ** The circumstances under which SQLite will enforce the soft heap limit may 5796 ** changes in future releases of SQLite. 5797 */ 5798 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5799 5800 /* 5801 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5802 ** DEPRECATED 5803 ** 5804 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5805 ** interface. This routine is provided for historical compatibility 5806 ** only. All new applications should use the 5807 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5808 */ 5809 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5810 5811 5812 /* 5813 ** CAPI3REF: Extract Metadata About A Column Of A Table 5814 ** METHOD: sqlite3 5815 ** 5816 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5817 ** information about column C of table T in database D 5818 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5819 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5820 ** the final five arguments with appropriate values if the specified 5821 ** column exists. ^The sqlite3_table_column_metadata() interface returns 5822 ** SQLITE_ERROR and if the specified column does not exist. 5823 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5824 ** NULL pointer, then this routine simply checks for the existence of the 5825 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5826 ** does not. If the table name parameter T in a call to 5827 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 5828 ** undefined behavior. 5829 ** 5830 ** ^The column is identified by the second, third and fourth parameters to 5831 ** this function. ^(The second parameter is either the name of the database 5832 ** (i.e. "main", "temp", or an attached database) containing the specified 5833 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5834 ** for the table using the same algorithm used by the database engine to 5835 ** resolve unqualified table references. 5836 ** 5837 ** ^The third and fourth parameters to this function are the table and column 5838 ** name of the desired column, respectively. 5839 ** 5840 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5841 ** and subsequent parameters to this function. ^Any of these arguments may be 5842 ** NULL, in which case the corresponding element of metadata is omitted. 5843 ** 5844 ** ^(<blockquote> 5845 ** <table border="1"> 5846 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5847 ** 5848 ** <tr><td> 5th <td> const char* <td> Data type 5849 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5850 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5851 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5852 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5853 ** </table> 5854 ** </blockquote>)^ 5855 ** 5856 ** ^The memory pointed to by the character pointers returned for the 5857 ** declaration type and collation sequence is valid until the next 5858 ** call to any SQLite API function. 5859 ** 5860 ** ^If the specified table is actually a view, an [error code] is returned. 5861 ** 5862 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5863 ** is not a [WITHOUT ROWID] table and an 5864 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5865 ** parameters are set for the explicitly declared column. ^(If there is no 5866 ** [INTEGER PRIMARY KEY] column, then the outputs 5867 ** for the [rowid] are set as follows: 5868 ** 5869 ** <pre> 5870 ** data type: "INTEGER" 5871 ** collation sequence: "BINARY" 5872 ** not null: 0 5873 ** primary key: 1 5874 ** auto increment: 0 5875 ** </pre>)^ 5876 ** 5877 ** ^This function causes all database schemas to be read from disk and 5878 ** parsed, if that has not already been done, and returns an error if 5879 ** any errors are encountered while loading the schema. 5880 */ 5881 SQLITE_API int sqlite3_table_column_metadata( 5882 sqlite3 *db, /* Connection handle */ 5883 const char *zDbName, /* Database name or NULL */ 5884 const char *zTableName, /* Table name */ 5885 const char *zColumnName, /* Column name */ 5886 char const **pzDataType, /* OUTPUT: Declared data type */ 5887 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5888 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5889 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5890 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5891 ); 5892 5893 /* 5894 ** CAPI3REF: Load An Extension 5895 ** METHOD: sqlite3 5896 ** 5897 ** ^This interface loads an SQLite extension library from the named file. 5898 ** 5899 ** ^The sqlite3_load_extension() interface attempts to load an 5900 ** [SQLite extension] library contained in the file zFile. If 5901 ** the file cannot be loaded directly, attempts are made to load 5902 ** with various operating-system specific extensions added. 5903 ** So for example, if "samplelib" cannot be loaded, then names like 5904 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5905 ** be tried also. 5906 ** 5907 ** ^The entry point is zProc. 5908 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5909 ** entry point name on its own. It first tries "sqlite3_extension_init". 5910 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5911 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5912 ** characters in the filename from the last "/" to the first following 5913 ** "." and omitting any initial "lib".)^ 5914 ** ^The sqlite3_load_extension() interface returns 5915 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5916 ** ^If an error occurs and pzErrMsg is not 0, then the 5917 ** [sqlite3_load_extension()] interface shall attempt to 5918 ** fill *pzErrMsg with error message text stored in memory 5919 ** obtained from [sqlite3_malloc()]. The calling function 5920 ** should free this memory by calling [sqlite3_free()]. 5921 ** 5922 ** ^Extension loading must be enabled using 5923 ** [sqlite3_enable_load_extension()] or 5924 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5925 ** prior to calling this API, 5926 ** otherwise an error will be returned. 5927 ** 5928 ** <b>Security warning:</b> It is recommended that the 5929 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5930 ** interface. The use of the [sqlite3_enable_load_extension()] interface 5931 ** should be avoided. This will keep the SQL function [load_extension()] 5932 ** disabled and prevent SQL injections from giving attackers 5933 ** access to extension loading capabilities. 5934 ** 5935 ** See also the [load_extension() SQL function]. 5936 */ 5937 SQLITE_API int sqlite3_load_extension( 5938 sqlite3 *db, /* Load the extension into this database connection */ 5939 const char *zFile, /* Name of the shared library containing extension */ 5940 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5941 char **pzErrMsg /* Put error message here if not 0 */ 5942 ); 5943 5944 /* 5945 ** CAPI3REF: Enable Or Disable Extension Loading 5946 ** METHOD: sqlite3 5947 ** 5948 ** ^So as not to open security holes in older applications that are 5949 ** unprepared to deal with [extension loading], and as a means of disabling 5950 ** [extension loading] while evaluating user-entered SQL, the following API 5951 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5952 ** 5953 ** ^Extension loading is off by default. 5954 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5955 ** to turn extension loading on and call it with onoff==0 to turn 5956 ** it back off again. 5957 ** 5958 ** ^This interface enables or disables both the C-API 5959 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5960 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5961 ** to enable or disable only the C-API.)^ 5962 ** 5963 ** <b>Security warning:</b> It is recommended that extension loading 5964 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5965 ** rather than this interface, so the [load_extension()] SQL function 5966 ** remains disabled. This will prevent SQL injections from giving attackers 5967 ** access to extension loading capabilities. 5968 */ 5969 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5970 5971 /* 5972 ** CAPI3REF: Automatically Load Statically Linked Extensions 5973 ** 5974 ** ^This interface causes the xEntryPoint() function to be invoked for 5975 ** each new [database connection] that is created. The idea here is that 5976 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5977 ** that is to be automatically loaded into all new database connections. 5978 ** 5979 ** ^(Even though the function prototype shows that xEntryPoint() takes 5980 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5981 ** arguments and expects an integer result as if the signature of the 5982 ** entry point where as follows: 5983 ** 5984 ** <blockquote><pre> 5985 ** int xEntryPoint( 5986 ** sqlite3 *db, 5987 ** const char **pzErrMsg, 5988 ** const struct sqlite3_api_routines *pThunk 5989 ** ); 5990 ** </pre></blockquote>)^ 5991 ** 5992 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5993 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5994 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5995 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5996 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5997 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5998 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5999 ** 6000 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6001 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6002 ** will be called more than once for each database connection that is opened. 6003 ** 6004 ** See also: [sqlite3_reset_auto_extension()] 6005 ** and [sqlite3_cancel_auto_extension()] 6006 */ 6007 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6008 6009 /* 6010 ** CAPI3REF: Cancel Automatic Extension Loading 6011 ** 6012 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6013 ** initialization routine X that was registered using a prior call to 6014 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6015 ** routine returns 1 if initialization routine X was successfully 6016 ** unregistered and it returns 0 if X was not on the list of initialization 6017 ** routines. 6018 */ 6019 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6020 6021 /* 6022 ** CAPI3REF: Reset Automatic Extension Loading 6023 ** 6024 ** ^This interface disables all automatic extensions previously 6025 ** registered using [sqlite3_auto_extension()]. 6026 */ 6027 SQLITE_API void sqlite3_reset_auto_extension(void); 6028 6029 /* 6030 ** The interface to the virtual-table mechanism is currently considered 6031 ** to be experimental. The interface might change in incompatible ways. 6032 ** If this is a problem for you, do not use the interface at this time. 6033 ** 6034 ** When the virtual-table mechanism stabilizes, we will declare the 6035 ** interface fixed, support it indefinitely, and remove this comment. 6036 */ 6037 6038 /* 6039 ** Structures used by the virtual table interface 6040 */ 6041 typedef struct sqlite3_vtab sqlite3_vtab; 6042 typedef struct sqlite3_index_info sqlite3_index_info; 6043 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6044 typedef struct sqlite3_module sqlite3_module; 6045 6046 /* 6047 ** CAPI3REF: Virtual Table Object 6048 ** KEYWORDS: sqlite3_module {virtual table module} 6049 ** 6050 ** This structure, sometimes called a "virtual table module", 6051 ** defines the implementation of a [virtual tables]. 6052 ** This structure consists mostly of methods for the module. 6053 ** 6054 ** ^A virtual table module is created by filling in a persistent 6055 ** instance of this structure and passing a pointer to that instance 6056 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6057 ** ^The registration remains valid until it is replaced by a different 6058 ** module or until the [database connection] closes. The content 6059 ** of this structure must not change while it is registered with 6060 ** any database connection. 6061 */ 6062 struct sqlite3_module { 6063 int iVersion; 6064 int (*xCreate)(sqlite3*, void *pAux, 6065 int argc, const char *const*argv, 6066 sqlite3_vtab **ppVTab, char**); 6067 int (*xConnect)(sqlite3*, void *pAux, 6068 int argc, const char *const*argv, 6069 sqlite3_vtab **ppVTab, char**); 6070 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6071 int (*xDisconnect)(sqlite3_vtab *pVTab); 6072 int (*xDestroy)(sqlite3_vtab *pVTab); 6073 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6074 int (*xClose)(sqlite3_vtab_cursor*); 6075 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6076 int argc, sqlite3_value **argv); 6077 int (*xNext)(sqlite3_vtab_cursor*); 6078 int (*xEof)(sqlite3_vtab_cursor*); 6079 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6080 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6081 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6082 int (*xBegin)(sqlite3_vtab *pVTab); 6083 int (*xSync)(sqlite3_vtab *pVTab); 6084 int (*xCommit)(sqlite3_vtab *pVTab); 6085 int (*xRollback)(sqlite3_vtab *pVTab); 6086 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6087 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6088 void **ppArg); 6089 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6090 /* The methods above are in version 1 of the sqlite_module object. Those 6091 ** below are for version 2 and greater. */ 6092 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6093 int (*xRelease)(sqlite3_vtab *pVTab, int); 6094 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6095 }; 6096 6097 /* 6098 ** CAPI3REF: Virtual Table Indexing Information 6099 ** KEYWORDS: sqlite3_index_info 6100 ** 6101 ** The sqlite3_index_info structure and its substructures is used as part 6102 ** of the [virtual table] interface to 6103 ** pass information into and receive the reply from the [xBestIndex] 6104 ** method of a [virtual table module]. The fields under **Inputs** are the 6105 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6106 ** results into the **Outputs** fields. 6107 ** 6108 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6109 ** 6110 ** <blockquote>column OP expr</blockquote> 6111 ** 6112 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6113 ** stored in aConstraint[].op using one of the 6114 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6115 ** ^(The index of the column is stored in 6116 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6117 ** expr on the right-hand side can be evaluated (and thus the constraint 6118 ** is usable) and false if it cannot.)^ 6119 ** 6120 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6121 ** and makes other simplifications to the WHERE clause in an attempt to 6122 ** get as many WHERE clause terms into the form shown above as possible. 6123 ** ^The aConstraint[] array only reports WHERE clause terms that are 6124 ** relevant to the particular virtual table being queried. 6125 ** 6126 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6127 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6128 ** 6129 ** The colUsed field indicates which columns of the virtual table may be 6130 ** required by the current scan. Virtual table columns are numbered from 6131 ** zero in the order in which they appear within the CREATE TABLE statement 6132 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6133 ** the corresponding bit is set within the colUsed mask if the column may be 6134 ** required by SQLite. If the table has at least 64 columns and any column 6135 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6136 ** set. In other words, column iCol may be required if the expression 6137 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6138 ** non-zero. 6139 ** 6140 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6141 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6142 ** the right-hand side of the corresponding aConstraint[] is evaluated 6143 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6144 ** is true, then the constraint is assumed to be fully handled by the 6145 ** virtual table and is not checked again by SQLite.)^ 6146 ** 6147 ** ^The idxNum and idxPtr values are recorded and passed into the 6148 ** [xFilter] method. 6149 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6150 ** needToFreeIdxPtr is true. 6151 ** 6152 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6153 ** the correct order to satisfy the ORDER BY clause so that no separate 6154 ** sorting step is required. 6155 ** 6156 ** ^The estimatedCost value is an estimate of the cost of a particular 6157 ** strategy. A cost of N indicates that the cost of the strategy is similar 6158 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6159 ** indicates that the expense of the operation is similar to that of a 6160 ** binary search on a unique indexed field of an SQLite table with N rows. 6161 ** 6162 ** ^The estimatedRows value is an estimate of the number of rows that 6163 ** will be returned by the strategy. 6164 ** 6165 ** The xBestIndex method may optionally populate the idxFlags field with a 6166 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6167 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6168 ** assumes that the strategy may visit at most one row. 6169 ** 6170 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6171 ** SQLite also assumes that if a call to the xUpdate() method is made as 6172 ** part of the same statement to delete or update a virtual table row and the 6173 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6174 ** any database changes. In other words, if the xUpdate() returns 6175 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6176 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6177 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6178 ** the xUpdate method are automatically rolled back by SQLite. 6179 ** 6180 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6181 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6182 ** If a virtual table extension is 6183 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6184 ** to read or write the estimatedRows field are undefined (but are likely 6185 ** to included crashing the application). The estimatedRows field should 6186 ** therefore only be used if [sqlite3_libversion_number()] returns a 6187 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6188 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6189 ** It may therefore only be used if 6190 ** sqlite3_libversion_number() returns a value greater than or equal to 6191 ** 3009000. 6192 */ 6193 struct sqlite3_index_info { 6194 /* Inputs */ 6195 int nConstraint; /* Number of entries in aConstraint */ 6196 struct sqlite3_index_constraint { 6197 int iColumn; /* Column constrained. -1 for ROWID */ 6198 unsigned char op; /* Constraint operator */ 6199 unsigned char usable; /* True if this constraint is usable */ 6200 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6201 } *aConstraint; /* Table of WHERE clause constraints */ 6202 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6203 struct sqlite3_index_orderby { 6204 int iColumn; /* Column number */ 6205 unsigned char desc; /* True for DESC. False for ASC. */ 6206 } *aOrderBy; /* The ORDER BY clause */ 6207 /* Outputs */ 6208 struct sqlite3_index_constraint_usage { 6209 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6210 unsigned char omit; /* Do not code a test for this constraint */ 6211 } *aConstraintUsage; 6212 int idxNum; /* Number used to identify the index */ 6213 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6214 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6215 int orderByConsumed; /* True if output is already ordered */ 6216 double estimatedCost; /* Estimated cost of using this index */ 6217 /* Fields below are only available in SQLite 3.8.2 and later */ 6218 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6219 /* Fields below are only available in SQLite 3.9.0 and later */ 6220 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6221 /* Fields below are only available in SQLite 3.10.0 and later */ 6222 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6223 }; 6224 6225 /* 6226 ** CAPI3REF: Virtual Table Scan Flags 6227 */ 6228 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6229 6230 /* 6231 ** CAPI3REF: Virtual Table Constraint Operator Codes 6232 ** 6233 ** These macros defined the allowed values for the 6234 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6235 ** an operator that is part of a constraint term in the wHERE clause of 6236 ** a query that uses a [virtual table]. 6237 */ 6238 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6239 #define SQLITE_INDEX_CONSTRAINT_GT 4 6240 #define SQLITE_INDEX_CONSTRAINT_LE 8 6241 #define SQLITE_INDEX_CONSTRAINT_LT 16 6242 #define SQLITE_INDEX_CONSTRAINT_GE 32 6243 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6244 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6245 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6246 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6247 #define SQLITE_INDEX_CONSTRAINT_NE 68 6248 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6249 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6250 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6251 #define SQLITE_INDEX_CONSTRAINT_IS 72 6252 6253 /* 6254 ** CAPI3REF: Register A Virtual Table Implementation 6255 ** METHOD: sqlite3 6256 ** 6257 ** ^These routines are used to register a new [virtual table module] name. 6258 ** ^Module names must be registered before 6259 ** creating a new [virtual table] using the module and before using a 6260 ** preexisting [virtual table] for the module. 6261 ** 6262 ** ^The module name is registered on the [database connection] specified 6263 ** by the first parameter. ^The name of the module is given by the 6264 ** second parameter. ^The third parameter is a pointer to 6265 ** the implementation of the [virtual table module]. ^The fourth 6266 ** parameter is an arbitrary client data pointer that is passed through 6267 ** into the [xCreate] and [xConnect] methods of the virtual table module 6268 ** when a new virtual table is be being created or reinitialized. 6269 ** 6270 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6271 ** is a pointer to a destructor for the pClientData. ^SQLite will 6272 ** invoke the destructor function (if it is not NULL) when SQLite 6273 ** no longer needs the pClientData pointer. ^The destructor will also 6274 ** be invoked if the call to sqlite3_create_module_v2() fails. 6275 ** ^The sqlite3_create_module() 6276 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6277 ** destructor. 6278 */ 6279 SQLITE_API int sqlite3_create_module( 6280 sqlite3 *db, /* SQLite connection to register module with */ 6281 const char *zName, /* Name of the module */ 6282 const sqlite3_module *p, /* Methods for the module */ 6283 void *pClientData /* Client data for xCreate/xConnect */ 6284 ); 6285 SQLITE_API int sqlite3_create_module_v2( 6286 sqlite3 *db, /* SQLite connection to register module with */ 6287 const char *zName, /* Name of the module */ 6288 const sqlite3_module *p, /* Methods for the module */ 6289 void *pClientData, /* Client data for xCreate/xConnect */ 6290 void(*xDestroy)(void*) /* Module destructor function */ 6291 ); 6292 6293 /* 6294 ** CAPI3REF: Virtual Table Instance Object 6295 ** KEYWORDS: sqlite3_vtab 6296 ** 6297 ** Every [virtual table module] implementation uses a subclass 6298 ** of this object to describe a particular instance 6299 ** of the [virtual table]. Each subclass will 6300 ** be tailored to the specific needs of the module implementation. 6301 ** The purpose of this superclass is to define certain fields that are 6302 ** common to all module implementations. 6303 ** 6304 ** ^Virtual tables methods can set an error message by assigning a 6305 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6306 ** take care that any prior string is freed by a call to [sqlite3_free()] 6307 ** prior to assigning a new string to zErrMsg. ^After the error message 6308 ** is delivered up to the client application, the string will be automatically 6309 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6310 */ 6311 struct sqlite3_vtab { 6312 const sqlite3_module *pModule; /* The module for this virtual table */ 6313 int nRef; /* Number of open cursors */ 6314 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6315 /* Virtual table implementations will typically add additional fields */ 6316 }; 6317 6318 /* 6319 ** CAPI3REF: Virtual Table Cursor Object 6320 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6321 ** 6322 ** Every [virtual table module] implementation uses a subclass of the 6323 ** following structure to describe cursors that point into the 6324 ** [virtual table] and are used 6325 ** to loop through the virtual table. Cursors are created using the 6326 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6327 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6328 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6329 ** of the module. Each module implementation will define 6330 ** the content of a cursor structure to suit its own needs. 6331 ** 6332 ** This superclass exists in order to define fields of the cursor that 6333 ** are common to all implementations. 6334 */ 6335 struct sqlite3_vtab_cursor { 6336 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6337 /* Virtual table implementations will typically add additional fields */ 6338 }; 6339 6340 /* 6341 ** CAPI3REF: Declare The Schema Of A Virtual Table 6342 ** 6343 ** ^The [xCreate] and [xConnect] methods of a 6344 ** [virtual table module] call this interface 6345 ** to declare the format (the names and datatypes of the columns) of 6346 ** the virtual tables they implement. 6347 */ 6348 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6349 6350 /* 6351 ** CAPI3REF: Overload A Function For A Virtual Table 6352 ** METHOD: sqlite3 6353 ** 6354 ** ^(Virtual tables can provide alternative implementations of functions 6355 ** using the [xFindFunction] method of the [virtual table module]. 6356 ** But global versions of those functions 6357 ** must exist in order to be overloaded.)^ 6358 ** 6359 ** ^(This API makes sure a global version of a function with a particular 6360 ** name and number of parameters exists. If no such function exists 6361 ** before this API is called, a new function is created.)^ ^The implementation 6362 ** of the new function always causes an exception to be thrown. So 6363 ** the new function is not good for anything by itself. Its only 6364 ** purpose is to be a placeholder function that can be overloaded 6365 ** by a [virtual table]. 6366 */ 6367 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6368 6369 /* 6370 ** The interface to the virtual-table mechanism defined above (back up 6371 ** to a comment remarkably similar to this one) is currently considered 6372 ** to be experimental. The interface might change in incompatible ways. 6373 ** If this is a problem for you, do not use the interface at this time. 6374 ** 6375 ** When the virtual-table mechanism stabilizes, we will declare the 6376 ** interface fixed, support it indefinitely, and remove this comment. 6377 */ 6378 6379 /* 6380 ** CAPI3REF: A Handle To An Open BLOB 6381 ** KEYWORDS: {BLOB handle} {BLOB handles} 6382 ** 6383 ** An instance of this object represents an open BLOB on which 6384 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6385 ** ^Objects of this type are created by [sqlite3_blob_open()] 6386 ** and destroyed by [sqlite3_blob_close()]. 6387 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6388 ** can be used to read or write small subsections of the BLOB. 6389 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6390 */ 6391 typedef struct sqlite3_blob sqlite3_blob; 6392 6393 /* 6394 ** CAPI3REF: Open A BLOB For Incremental I/O 6395 ** METHOD: sqlite3 6396 ** CONSTRUCTOR: sqlite3_blob 6397 ** 6398 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6399 ** in row iRow, column zColumn, table zTable in database zDb; 6400 ** in other words, the same BLOB that would be selected by: 6401 ** 6402 ** <pre> 6403 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6404 ** </pre>)^ 6405 ** 6406 ** ^(Parameter zDb is not the filename that contains the database, but 6407 ** rather the symbolic name of the database. For attached databases, this is 6408 ** the name that appears after the AS keyword in the [ATTACH] statement. 6409 ** For the main database file, the database name is "main". For TEMP 6410 ** tables, the database name is "temp".)^ 6411 ** 6412 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6413 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6414 ** read-only access. 6415 ** 6416 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6417 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6418 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6419 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6420 ** on *ppBlob after this function it returns. 6421 ** 6422 ** This function fails with SQLITE_ERROR if any of the following are true: 6423 ** <ul> 6424 ** <li> ^(Database zDb does not exist)^, 6425 ** <li> ^(Table zTable does not exist within database zDb)^, 6426 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6427 ** <li> ^(Column zColumn does not exist)^, 6428 ** <li> ^(Row iRow is not present in the table)^, 6429 ** <li> ^(The specified column of row iRow contains a value that is not 6430 ** a TEXT or BLOB value)^, 6431 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6432 ** constraint and the blob is being opened for read/write access)^, 6433 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6434 ** column zColumn is part of a [child key] definition and the blob is 6435 ** being opened for read/write access)^. 6436 ** </ul> 6437 ** 6438 ** ^Unless it returns SQLITE_MISUSE, this function sets the 6439 ** [database connection] error code and message accessible via 6440 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6441 ** 6442 ** A BLOB referenced by sqlite3_blob_open() may be read using the 6443 ** [sqlite3_blob_read()] interface and modified by using 6444 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6445 ** different row of the same table using the [sqlite3_blob_reopen()] 6446 ** interface. However, the column, table, or database of a [BLOB handle] 6447 ** cannot be changed after the [BLOB handle] is opened. 6448 ** 6449 ** ^(If the row that a BLOB handle points to is modified by an 6450 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6451 ** then the BLOB handle is marked as "expired". 6452 ** This is true if any column of the row is changed, even a column 6453 ** other than the one the BLOB handle is open on.)^ 6454 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6455 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6456 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6457 ** rolled back by the expiration of the BLOB. Such changes will eventually 6458 ** commit if the transaction continues to completion.)^ 6459 ** 6460 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6461 ** the opened blob. ^The size of a blob may not be changed by this 6462 ** interface. Use the [UPDATE] SQL command to change the size of a 6463 ** blob. 6464 ** 6465 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6466 ** and the built-in [zeroblob] SQL function may be used to create a 6467 ** zero-filled blob to read or write using the incremental-blob interface. 6468 ** 6469 ** To avoid a resource leak, every open [BLOB handle] should eventually 6470 ** be released by a call to [sqlite3_blob_close()]. 6471 ** 6472 ** See also: [sqlite3_blob_close()], 6473 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6474 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6475 */ 6476 SQLITE_API int sqlite3_blob_open( 6477 sqlite3*, 6478 const char *zDb, 6479 const char *zTable, 6480 const char *zColumn, 6481 sqlite3_int64 iRow, 6482 int flags, 6483 sqlite3_blob **ppBlob 6484 ); 6485 6486 /* 6487 ** CAPI3REF: Move a BLOB Handle to a New Row 6488 ** METHOD: sqlite3_blob 6489 ** 6490 ** ^This function is used to move an existing [BLOB handle] so that it points 6491 ** to a different row of the same database table. ^The new row is identified 6492 ** by the rowid value passed as the second argument. Only the row can be 6493 ** changed. ^The database, table and column on which the blob handle is open 6494 ** remain the same. Moving an existing [BLOB handle] to a new row is 6495 ** faster than closing the existing handle and opening a new one. 6496 ** 6497 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6498 ** it must exist and there must be either a blob or text value stored in 6499 ** the nominated column.)^ ^If the new row is not present in the table, or if 6500 ** it does not contain a blob or text value, or if another error occurs, an 6501 ** SQLite error code is returned and the blob handle is considered aborted. 6502 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6503 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6504 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6505 ** always returns zero. 6506 ** 6507 ** ^This function sets the database handle error code and message. 6508 */ 6509 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6510 6511 /* 6512 ** CAPI3REF: Close A BLOB Handle 6513 ** DESTRUCTOR: sqlite3_blob 6514 ** 6515 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6516 ** unconditionally. Even if this routine returns an error code, the 6517 ** handle is still closed.)^ 6518 ** 6519 ** ^If the blob handle being closed was opened for read-write access, and if 6520 ** the database is in auto-commit mode and there are no other open read-write 6521 ** blob handles or active write statements, the current transaction is 6522 ** committed. ^If an error occurs while committing the transaction, an error 6523 ** code is returned and the transaction rolled back. 6524 ** 6525 ** Calling this function with an argument that is not a NULL pointer or an 6526 ** open blob handle results in undefined behaviour. ^Calling this routine 6527 ** with a null pointer (such as would be returned by a failed call to 6528 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6529 ** is passed a valid open blob handle, the values returned by the 6530 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6531 */ 6532 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6533 6534 /* 6535 ** CAPI3REF: Return The Size Of An Open BLOB 6536 ** METHOD: sqlite3_blob 6537 ** 6538 ** ^Returns the size in bytes of the BLOB accessible via the 6539 ** successfully opened [BLOB handle] in its only argument. ^The 6540 ** incremental blob I/O routines can only read or overwriting existing 6541 ** blob content; they cannot change the size of a blob. 6542 ** 6543 ** This routine only works on a [BLOB handle] which has been created 6544 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6545 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6546 ** to this routine results in undefined and probably undesirable behavior. 6547 */ 6548 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6549 6550 /* 6551 ** CAPI3REF: Read Data From A BLOB Incrementally 6552 ** METHOD: sqlite3_blob 6553 ** 6554 ** ^(This function is used to read data from an open [BLOB handle] into a 6555 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6556 ** from the open BLOB, starting at offset iOffset.)^ 6557 ** 6558 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6559 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6560 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6561 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6562 ** can be determined using the [sqlite3_blob_bytes()] interface. 6563 ** 6564 ** ^An attempt to read from an expired [BLOB handle] fails with an 6565 ** error code of [SQLITE_ABORT]. 6566 ** 6567 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6568 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6569 ** 6570 ** This routine only works on a [BLOB handle] which has been created 6571 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6572 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6573 ** to this routine results in undefined and probably undesirable behavior. 6574 ** 6575 ** See also: [sqlite3_blob_write()]. 6576 */ 6577 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6578 6579 /* 6580 ** CAPI3REF: Write Data Into A BLOB Incrementally 6581 ** METHOD: sqlite3_blob 6582 ** 6583 ** ^(This function is used to write data into an open [BLOB handle] from a 6584 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6585 ** into the open BLOB, starting at offset iOffset.)^ 6586 ** 6587 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6588 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6589 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6590 ** [database connection] error code and message accessible via 6591 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6592 ** 6593 ** ^If the [BLOB handle] passed as the first argument was not opened for 6594 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6595 ** this function returns [SQLITE_READONLY]. 6596 ** 6597 ** This function may only modify the contents of the BLOB; it is 6598 ** not possible to increase the size of a BLOB using this API. 6599 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6600 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6601 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6602 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6603 ** than zero [SQLITE_ERROR] is returned and no data is written. 6604 ** 6605 ** ^An attempt to write to an expired [BLOB handle] fails with an 6606 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6607 ** before the [BLOB handle] expired are not rolled back by the 6608 ** expiration of the handle, though of course those changes might 6609 ** have been overwritten by the statement that expired the BLOB handle 6610 ** or by other independent statements. 6611 ** 6612 ** This routine only works on a [BLOB handle] which has been created 6613 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6614 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6615 ** to this routine results in undefined and probably undesirable behavior. 6616 ** 6617 ** See also: [sqlite3_blob_read()]. 6618 */ 6619 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6620 6621 /* 6622 ** CAPI3REF: Virtual File System Objects 6623 ** 6624 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6625 ** that SQLite uses to interact 6626 ** with the underlying operating system. Most SQLite builds come with a 6627 ** single default VFS that is appropriate for the host computer. 6628 ** New VFSes can be registered and existing VFSes can be unregistered. 6629 ** The following interfaces are provided. 6630 ** 6631 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6632 ** ^Names are case sensitive. 6633 ** ^Names are zero-terminated UTF-8 strings. 6634 ** ^If there is no match, a NULL pointer is returned. 6635 ** ^If zVfsName is NULL then the default VFS is returned. 6636 ** 6637 ** ^New VFSes are registered with sqlite3_vfs_register(). 6638 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6639 ** ^The same VFS can be registered multiple times without injury. 6640 ** ^To make an existing VFS into the default VFS, register it again 6641 ** with the makeDflt flag set. If two different VFSes with the 6642 ** same name are registered, the behavior is undefined. If a 6643 ** VFS is registered with a name that is NULL or an empty string, 6644 ** then the behavior is undefined. 6645 ** 6646 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6647 ** ^(If the default VFS is unregistered, another VFS is chosen as 6648 ** the default. The choice for the new VFS is arbitrary.)^ 6649 */ 6650 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6651 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6652 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6653 6654 /* 6655 ** CAPI3REF: Mutexes 6656 ** 6657 ** The SQLite core uses these routines for thread 6658 ** synchronization. Though they are intended for internal 6659 ** use by SQLite, code that links against SQLite is 6660 ** permitted to use any of these routines. 6661 ** 6662 ** The SQLite source code contains multiple implementations 6663 ** of these mutex routines. An appropriate implementation 6664 ** is selected automatically at compile-time. The following 6665 ** implementations are available in the SQLite core: 6666 ** 6667 ** <ul> 6668 ** <li> SQLITE_MUTEX_PTHREADS 6669 ** <li> SQLITE_MUTEX_W32 6670 ** <li> SQLITE_MUTEX_NOOP 6671 ** </ul> 6672 ** 6673 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6674 ** that does no real locking and is appropriate for use in 6675 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6676 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6677 ** and Windows. 6678 ** 6679 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6680 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6681 ** implementation is included with the library. In this case the 6682 ** application must supply a custom mutex implementation using the 6683 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6684 ** before calling sqlite3_initialize() or any other public sqlite3_ 6685 ** function that calls sqlite3_initialize(). 6686 ** 6687 ** ^The sqlite3_mutex_alloc() routine allocates a new 6688 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6689 ** routine returns NULL if it is unable to allocate the requested 6690 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6691 ** integer constants: 6692 ** 6693 ** <ul> 6694 ** <li> SQLITE_MUTEX_FAST 6695 ** <li> SQLITE_MUTEX_RECURSIVE 6696 ** <li> SQLITE_MUTEX_STATIC_MASTER 6697 ** <li> SQLITE_MUTEX_STATIC_MEM 6698 ** <li> SQLITE_MUTEX_STATIC_OPEN 6699 ** <li> SQLITE_MUTEX_STATIC_PRNG 6700 ** <li> SQLITE_MUTEX_STATIC_LRU 6701 ** <li> SQLITE_MUTEX_STATIC_PMEM 6702 ** <li> SQLITE_MUTEX_STATIC_APP1 6703 ** <li> SQLITE_MUTEX_STATIC_APP2 6704 ** <li> SQLITE_MUTEX_STATIC_APP3 6705 ** <li> SQLITE_MUTEX_STATIC_VFS1 6706 ** <li> SQLITE_MUTEX_STATIC_VFS2 6707 ** <li> SQLITE_MUTEX_STATIC_VFS3 6708 ** </ul> 6709 ** 6710 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6711 ** cause sqlite3_mutex_alloc() to create 6712 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6713 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6714 ** The mutex implementation does not need to make a distinction 6715 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6716 ** not want to. SQLite will only request a recursive mutex in 6717 ** cases where it really needs one. If a faster non-recursive mutex 6718 ** implementation is available on the host platform, the mutex subsystem 6719 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6720 ** 6721 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6722 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6723 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6724 ** used by the current version of SQLite. Future versions of SQLite 6725 ** may add additional static mutexes. Static mutexes are for internal 6726 ** use by SQLite only. Applications that use SQLite mutexes should 6727 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6728 ** SQLITE_MUTEX_RECURSIVE. 6729 ** 6730 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6731 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6732 ** returns a different mutex on every call. ^For the static 6733 ** mutex types, the same mutex is returned on every call that has 6734 ** the same type number. 6735 ** 6736 ** ^The sqlite3_mutex_free() routine deallocates a previously 6737 ** allocated dynamic mutex. Attempting to deallocate a static 6738 ** mutex results in undefined behavior. 6739 ** 6740 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6741 ** to enter a mutex. ^If another thread is already within the mutex, 6742 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6743 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6744 ** upon successful entry. ^(Mutexes created using 6745 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6746 ** In such cases, the 6747 ** mutex must be exited an equal number of times before another thread 6748 ** can enter.)^ If the same thread tries to enter any mutex other 6749 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6750 ** 6751 ** ^(Some systems (for example, Windows 95) do not support the operation 6752 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6753 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6754 ** sqlite3_mutex_try() as an optimization so this is acceptable 6755 ** behavior.)^ 6756 ** 6757 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6758 ** previously entered by the same thread. The behavior 6759 ** is undefined if the mutex is not currently entered by the 6760 ** calling thread or is not currently allocated. 6761 ** 6762 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6763 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6764 ** behave as no-ops. 6765 ** 6766 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6767 */ 6768 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 6769 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 6770 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 6771 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 6772 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 6773 6774 /* 6775 ** CAPI3REF: Mutex Methods Object 6776 ** 6777 ** An instance of this structure defines the low-level routines 6778 ** used to allocate and use mutexes. 6779 ** 6780 ** Usually, the default mutex implementations provided by SQLite are 6781 ** sufficient, however the application has the option of substituting a custom 6782 ** implementation for specialized deployments or systems for which SQLite 6783 ** does not provide a suitable implementation. In this case, the application 6784 ** creates and populates an instance of this structure to pass 6785 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6786 ** Additionally, an instance of this structure can be used as an 6787 ** output variable when querying the system for the current mutex 6788 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6789 ** 6790 ** ^The xMutexInit method defined by this structure is invoked as 6791 ** part of system initialization by the sqlite3_initialize() function. 6792 ** ^The xMutexInit routine is called by SQLite exactly once for each 6793 ** effective call to [sqlite3_initialize()]. 6794 ** 6795 ** ^The xMutexEnd method defined by this structure is invoked as 6796 ** part of system shutdown by the sqlite3_shutdown() function. The 6797 ** implementation of this method is expected to release all outstanding 6798 ** resources obtained by the mutex methods implementation, especially 6799 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6800 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6801 ** 6802 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6803 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6804 ** xMutexNotheld) implement the following interfaces (respectively): 6805 ** 6806 ** <ul> 6807 ** <li> [sqlite3_mutex_alloc()] </li> 6808 ** <li> [sqlite3_mutex_free()] </li> 6809 ** <li> [sqlite3_mutex_enter()] </li> 6810 ** <li> [sqlite3_mutex_try()] </li> 6811 ** <li> [sqlite3_mutex_leave()] </li> 6812 ** <li> [sqlite3_mutex_held()] </li> 6813 ** <li> [sqlite3_mutex_notheld()] </li> 6814 ** </ul>)^ 6815 ** 6816 ** The only difference is that the public sqlite3_XXX functions enumerated 6817 ** above silently ignore any invocations that pass a NULL pointer instead 6818 ** of a valid mutex handle. The implementations of the methods defined 6819 ** by this structure are not required to handle this case, the results 6820 ** of passing a NULL pointer instead of a valid mutex handle are undefined 6821 ** (i.e. it is acceptable to provide an implementation that segfaults if 6822 ** it is passed a NULL pointer). 6823 ** 6824 ** The xMutexInit() method must be threadsafe. It must be harmless to 6825 ** invoke xMutexInit() multiple times within the same process and without 6826 ** intervening calls to xMutexEnd(). Second and subsequent calls to 6827 ** xMutexInit() must be no-ops. 6828 ** 6829 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6830 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6831 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6832 ** memory allocation for a fast or recursive mutex. 6833 ** 6834 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6835 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6836 ** If xMutexInit fails in any way, it is expected to clean up after itself 6837 ** prior to returning. 6838 */ 6839 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6840 struct sqlite3_mutex_methods { 6841 int (*xMutexInit)(void); 6842 int (*xMutexEnd)(void); 6843 sqlite3_mutex *(*xMutexAlloc)(int); 6844 void (*xMutexFree)(sqlite3_mutex *); 6845 void (*xMutexEnter)(sqlite3_mutex *); 6846 int (*xMutexTry)(sqlite3_mutex *); 6847 void (*xMutexLeave)(sqlite3_mutex *); 6848 int (*xMutexHeld)(sqlite3_mutex *); 6849 int (*xMutexNotheld)(sqlite3_mutex *); 6850 }; 6851 6852 /* 6853 ** CAPI3REF: Mutex Verification Routines 6854 ** 6855 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6856 ** are intended for use inside assert() statements. The SQLite core 6857 ** never uses these routines except inside an assert() and applications 6858 ** are advised to follow the lead of the core. The SQLite core only 6859 ** provides implementations for these routines when it is compiled 6860 ** with the SQLITE_DEBUG flag. External mutex implementations 6861 ** are only required to provide these routines if SQLITE_DEBUG is 6862 ** defined and if NDEBUG is not defined. 6863 ** 6864 ** These routines should return true if the mutex in their argument 6865 ** is held or not held, respectively, by the calling thread. 6866 ** 6867 ** The implementation is not required to provide versions of these 6868 ** routines that actually work. If the implementation does not provide working 6869 ** versions of these routines, it should at least provide stubs that always 6870 ** return true so that one does not get spurious assertion failures. 6871 ** 6872 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6873 ** the routine should return 1. This seems counter-intuitive since 6874 ** clearly the mutex cannot be held if it does not exist. But 6875 ** the reason the mutex does not exist is because the build is not 6876 ** using mutexes. And we do not want the assert() containing the 6877 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6878 ** the appropriate thing to do. The sqlite3_mutex_notheld() 6879 ** interface should also return 1 when given a NULL pointer. 6880 */ 6881 #ifndef NDEBUG 6882 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 6883 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 6884 #endif 6885 6886 /* 6887 ** CAPI3REF: Mutex Types 6888 ** 6889 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6890 ** which is one of these integer constants. 6891 ** 6892 ** The set of static mutexes may change from one SQLite release to the 6893 ** next. Applications that override the built-in mutex logic must be 6894 ** prepared to accommodate additional static mutexes. 6895 */ 6896 #define SQLITE_MUTEX_FAST 0 6897 #define SQLITE_MUTEX_RECURSIVE 1 6898 #define SQLITE_MUTEX_STATIC_MASTER 2 6899 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6900 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6901 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6902 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 6903 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6904 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6905 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6906 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6907 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6908 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6909 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6910 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6911 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6912 6913 /* 6914 ** CAPI3REF: Retrieve the mutex for a database connection 6915 ** METHOD: sqlite3 6916 ** 6917 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6918 ** serializes access to the [database connection] given in the argument 6919 ** when the [threading mode] is Serialized. 6920 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6921 ** routine returns a NULL pointer. 6922 */ 6923 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6924 6925 /* 6926 ** CAPI3REF: Low-Level Control Of Database Files 6927 ** METHOD: sqlite3 6928 ** 6929 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6930 ** xFileControl method for the [sqlite3_io_methods] object associated 6931 ** with a particular database identified by the second argument. ^The 6932 ** name of the database is "main" for the main database or "temp" for the 6933 ** TEMP database, or the name that appears after the AS keyword for 6934 ** databases that are added using the [ATTACH] SQL command. 6935 ** ^A NULL pointer can be used in place of "main" to refer to the 6936 ** main database file. 6937 ** ^The third and fourth parameters to this routine 6938 ** are passed directly through to the second and third parameters of 6939 ** the xFileControl method. ^The return value of the xFileControl 6940 ** method becomes the return value of this routine. 6941 ** 6942 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 6943 ** a pointer to the underlying [sqlite3_file] object to be written into 6944 ** the space pointed to by the 4th parameter. ^The [SQLITE_FCNTL_FILE_POINTER] 6945 ** case is a short-circuit path which does not actually invoke the 6946 ** underlying sqlite3_io_methods.xFileControl method. 6947 ** 6948 ** ^If the second parameter (zDbName) does not match the name of any 6949 ** open database file, then SQLITE_ERROR is returned. ^This error 6950 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6951 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6952 ** also return SQLITE_ERROR. There is no way to distinguish between 6953 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6954 ** xFileControl method. 6955 ** 6956 ** See also: [file control opcodes] 6957 */ 6958 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6959 6960 /* 6961 ** CAPI3REF: Testing Interface 6962 ** 6963 ** ^The sqlite3_test_control() interface is used to read out internal 6964 ** state of SQLite and to inject faults into SQLite for testing 6965 ** purposes. ^The first parameter is an operation code that determines 6966 ** the number, meaning, and operation of all subsequent parameters. 6967 ** 6968 ** This interface is not for use by applications. It exists solely 6969 ** for verifying the correct operation of the SQLite library. Depending 6970 ** on how the SQLite library is compiled, this interface might not exist. 6971 ** 6972 ** The details of the operation codes, their meanings, the parameters 6973 ** they take, and what they do are all subject to change without notice. 6974 ** Unlike most of the SQLite API, this function is not guaranteed to 6975 ** operate consistently from one release to the next. 6976 */ 6977 SQLITE_API int sqlite3_test_control(int op, ...); 6978 6979 /* 6980 ** CAPI3REF: Testing Interface Operation Codes 6981 ** 6982 ** These constants are the valid operation code parameters used 6983 ** as the first argument to [sqlite3_test_control()]. 6984 ** 6985 ** These parameters and their meanings are subject to change 6986 ** without notice. These values are for testing purposes only. 6987 ** Applications should not use any of these parameters or the 6988 ** [sqlite3_test_control()] interface. 6989 */ 6990 #define SQLITE_TESTCTRL_FIRST 5 6991 #define SQLITE_TESTCTRL_PRNG_SAVE 5 6992 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6993 #define SQLITE_TESTCTRL_PRNG_RESET 7 6994 #define SQLITE_TESTCTRL_BITVEC_TEST 8 6995 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6996 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6997 #define SQLITE_TESTCTRL_PENDING_BYTE 11 6998 #define SQLITE_TESTCTRL_ASSERT 12 6999 #define SQLITE_TESTCTRL_ALWAYS 13 7000 #define SQLITE_TESTCTRL_RESERVE 14 7001 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7002 #define SQLITE_TESTCTRL_ISKEYWORD 16 7003 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7004 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7005 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7006 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7007 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7008 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7009 #define SQLITE_TESTCTRL_BYTEORDER 22 7010 #define SQLITE_TESTCTRL_ISINIT 23 7011 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7012 #define SQLITE_TESTCTRL_IMPOSTER 25 7013 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7014 #define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */ 7015 7016 /* 7017 ** CAPI3REF: SQLite Runtime Status 7018 ** 7019 ** ^These interfaces are used to retrieve runtime status information 7020 ** about the performance of SQLite, and optionally to reset various 7021 ** highwater marks. ^The first argument is an integer code for 7022 ** the specific parameter to measure. ^(Recognized integer codes 7023 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7024 ** ^The current value of the parameter is returned into *pCurrent. 7025 ** ^The highest recorded value is returned in *pHighwater. ^If the 7026 ** resetFlag is true, then the highest record value is reset after 7027 ** *pHighwater is written. ^(Some parameters do not record the highest 7028 ** value. For those parameters 7029 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7030 ** ^(Other parameters record only the highwater mark and not the current 7031 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7032 ** 7033 ** ^The sqlite3_status() and sqlite3_status64() routines return 7034 ** SQLITE_OK on success and a non-zero [error code] on failure. 7035 ** 7036 ** If either the current value or the highwater mark is too large to 7037 ** be represented by a 32-bit integer, then the values returned by 7038 ** sqlite3_status() are undefined. 7039 ** 7040 ** See also: [sqlite3_db_status()] 7041 */ 7042 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7043 SQLITE_API int sqlite3_status64( 7044 int op, 7045 sqlite3_int64 *pCurrent, 7046 sqlite3_int64 *pHighwater, 7047 int resetFlag 7048 ); 7049 7050 7051 /* 7052 ** CAPI3REF: Status Parameters 7053 ** KEYWORDS: {status parameters} 7054 ** 7055 ** These integer constants designate various run-time status parameters 7056 ** that can be returned by [sqlite3_status()]. 7057 ** 7058 ** <dl> 7059 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7060 ** <dd>This parameter is the current amount of memory checked out 7061 ** using [sqlite3_malloc()], either directly or indirectly. The 7062 ** figure includes calls made to [sqlite3_malloc()] by the application 7063 ** and internal memory usage by the SQLite library. Auxiliary page-cache 7064 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7065 ** this parameter. The amount returned is the sum of the allocation 7066 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7067 ** 7068 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7069 ** <dd>This parameter records the largest memory allocation request 7070 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7071 ** internal equivalents). Only the value returned in the 7072 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7073 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7074 ** 7075 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7076 ** <dd>This parameter records the number of separate memory allocations 7077 ** currently checked out.</dd>)^ 7078 ** 7079 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7080 ** <dd>This parameter returns the number of pages used out of the 7081 ** [pagecache memory allocator] that was configured using 7082 ** [SQLITE_CONFIG_PAGECACHE]. The 7083 ** value returned is in pages, not in bytes.</dd>)^ 7084 ** 7085 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7086 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7087 ** <dd>This parameter returns the number of bytes of page cache 7088 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7089 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 7090 ** returned value includes allocations that overflowed because they 7091 ** where too large (they were larger than the "sz" parameter to 7092 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7093 ** no space was left in the page cache.</dd>)^ 7094 ** 7095 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7096 ** <dd>This parameter records the largest memory allocation request 7097 ** handed to [pagecache memory allocator]. Only the value returned in the 7098 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7099 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7100 ** 7101 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7102 ** <dd>No longer used.</dd> 7103 ** 7104 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7105 ** <dd>No longer used.</dd> 7106 ** 7107 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7108 ** <dd>No longer used.</dd> 7109 ** 7110 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7111 ** <dd>The *pHighwater parameter records the deepest parser stack. 7112 ** The *pCurrent value is undefined. The *pHighwater value is only 7113 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7114 ** </dl> 7115 ** 7116 ** New status parameters may be added from time to time. 7117 */ 7118 #define SQLITE_STATUS_MEMORY_USED 0 7119 #define SQLITE_STATUS_PAGECACHE_USED 1 7120 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7121 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7122 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7123 #define SQLITE_STATUS_MALLOC_SIZE 5 7124 #define SQLITE_STATUS_PARSER_STACK 6 7125 #define SQLITE_STATUS_PAGECACHE_SIZE 7 7126 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7127 #define SQLITE_STATUS_MALLOC_COUNT 9 7128 7129 /* 7130 ** CAPI3REF: Database Connection Status 7131 ** METHOD: sqlite3 7132 ** 7133 ** ^This interface is used to retrieve runtime status information 7134 ** about a single [database connection]. ^The first argument is the 7135 ** database connection object to be interrogated. ^The second argument 7136 ** is an integer constant, taken from the set of 7137 ** [SQLITE_DBSTATUS options], that 7138 ** determines the parameter to interrogate. The set of 7139 ** [SQLITE_DBSTATUS options] is likely 7140 ** to grow in future releases of SQLite. 7141 ** 7142 ** ^The current value of the requested parameter is written into *pCur 7143 ** and the highest instantaneous value is written into *pHiwtr. ^If 7144 ** the resetFlg is true, then the highest instantaneous value is 7145 ** reset back down to the current value. 7146 ** 7147 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7148 ** non-zero [error code] on failure. 7149 ** 7150 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7151 */ 7152 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7153 7154 /* 7155 ** CAPI3REF: Status Parameters for database connections 7156 ** KEYWORDS: {SQLITE_DBSTATUS options} 7157 ** 7158 ** These constants are the available integer "verbs" that can be passed as 7159 ** the second argument to the [sqlite3_db_status()] interface. 7160 ** 7161 ** New verbs may be added in future releases of SQLite. Existing verbs 7162 ** might be discontinued. Applications should check the return code from 7163 ** [sqlite3_db_status()] to make sure that the call worked. 7164 ** The [sqlite3_db_status()] interface will return a non-zero error code 7165 ** if a discontinued or unsupported verb is invoked. 7166 ** 7167 ** <dl> 7168 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7169 ** <dd>This parameter returns the number of lookaside memory slots currently 7170 ** checked out.</dd>)^ 7171 ** 7172 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7173 ** <dd>This parameter returns the number malloc attempts that were 7174 ** satisfied using lookaside memory. Only the high-water value is meaningful; 7175 ** the current value is always zero.)^ 7176 ** 7177 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7178 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7179 ** <dd>This parameter returns the number malloc attempts that might have 7180 ** been satisfied using lookaside memory but failed due to the amount of 7181 ** memory requested being larger than the lookaside slot size. 7182 ** Only the high-water value is meaningful; 7183 ** the current value is always zero.)^ 7184 ** 7185 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7186 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7187 ** <dd>This parameter returns the number malloc attempts that might have 7188 ** been satisfied using lookaside memory but failed due to all lookaside 7189 ** memory already being in use. 7190 ** Only the high-water value is meaningful; 7191 ** the current value is always zero.)^ 7192 ** 7193 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7194 ** <dd>This parameter returns the approximate number of bytes of heap 7195 ** memory used by all pager caches associated with the database connection.)^ 7196 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7197 ** 7198 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7199 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7200 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7201 ** pager cache is shared between two or more connections the bytes of heap 7202 ** memory used by that pager cache is divided evenly between the attached 7203 ** connections.)^ In other words, if none of the pager caches associated 7204 ** with the database connection are shared, this request returns the same 7205 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7206 ** shared, the value returned by this call will be smaller than that returned 7207 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7208 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7209 ** 7210 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7211 ** <dd>This parameter returns the approximate number of bytes of heap 7212 ** memory used to store the schema for all databases associated 7213 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7214 ** ^The full amount of memory used by the schemas is reported, even if the 7215 ** schema memory is shared with other database connections due to 7216 ** [shared cache mode] being enabled. 7217 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7218 ** 7219 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7220 ** <dd>This parameter returns the approximate number of bytes of heap 7221 ** and lookaside memory used by all prepared statements associated with 7222 ** the database connection.)^ 7223 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7224 ** </dd> 7225 ** 7226 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7227 ** <dd>This parameter returns the number of pager cache hits that have 7228 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7229 ** is always 0. 7230 ** </dd> 7231 ** 7232 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7233 ** <dd>This parameter returns the number of pager cache misses that have 7234 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7235 ** is always 0. 7236 ** </dd> 7237 ** 7238 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7239 ** <dd>This parameter returns the number of dirty cache entries that have 7240 ** been written to disk. Specifically, the number of pages written to the 7241 ** wal file in wal mode databases, or the number of pages written to the 7242 ** database file in rollback mode databases. Any pages written as part of 7243 ** transaction rollback or database recovery operations are not included. 7244 ** If an IO or other error occurs while writing a page to disk, the effect 7245 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7246 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7247 ** </dd> 7248 ** 7249 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7250 ** <dd>This parameter returns the number of dirty cache entries that have 7251 ** been written to disk in the middle of a transaction due to the page 7252 ** cache overflowing. Transactions are more efficient if they are written 7253 ** to disk all at once. When pages spill mid-transaction, that introduces 7254 ** additional overhead. This parameter can be used help identify 7255 ** inefficiencies that can be resolve by increasing the cache size. 7256 ** </dd> 7257 ** 7258 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7259 ** <dd>This parameter returns zero for the current value if and only if 7260 ** all foreign key constraints (deferred or immediate) have been 7261 ** resolved.)^ ^The highwater mark is always 0. 7262 ** </dd> 7263 ** </dl> 7264 */ 7265 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7266 #define SQLITE_DBSTATUS_CACHE_USED 1 7267 #define SQLITE_DBSTATUS_SCHEMA_USED 2 7268 #define SQLITE_DBSTATUS_STMT_USED 3 7269 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7270 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7271 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7272 #define SQLITE_DBSTATUS_CACHE_HIT 7 7273 #define SQLITE_DBSTATUS_CACHE_MISS 8 7274 #define SQLITE_DBSTATUS_CACHE_WRITE 9 7275 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 7276 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7277 #define SQLITE_DBSTATUS_CACHE_SPILL 12 7278 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7279 7280 7281 /* 7282 ** CAPI3REF: Prepared Statement Status 7283 ** METHOD: sqlite3_stmt 7284 ** 7285 ** ^(Each prepared statement maintains various 7286 ** [SQLITE_STMTSTATUS counters] that measure the number 7287 ** of times it has performed specific operations.)^ These counters can 7288 ** be used to monitor the performance characteristics of the prepared 7289 ** statements. For example, if the number of table steps greatly exceeds 7290 ** the number of table searches or result rows, that would tend to indicate 7291 ** that the prepared statement is using a full table scan rather than 7292 ** an index. 7293 ** 7294 ** ^(This interface is used to retrieve and reset counter values from 7295 ** a [prepared statement]. The first argument is the prepared statement 7296 ** object to be interrogated. The second argument 7297 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7298 ** to be interrogated.)^ 7299 ** ^The current value of the requested counter is returned. 7300 ** ^If the resetFlg is true, then the counter is reset to zero after this 7301 ** interface call returns. 7302 ** 7303 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7304 */ 7305 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7306 7307 /* 7308 ** CAPI3REF: Status Parameters for prepared statements 7309 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7310 ** 7311 ** These preprocessor macros define integer codes that name counter 7312 ** values associated with the [sqlite3_stmt_status()] interface. 7313 ** The meanings of the various counters are as follows: 7314 ** 7315 ** <dl> 7316 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7317 ** <dd>^This is the number of times that SQLite has stepped forward in 7318 ** a table as part of a full table scan. Large numbers for this counter 7319 ** may indicate opportunities for performance improvement through 7320 ** careful use of indices.</dd> 7321 ** 7322 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7323 ** <dd>^This is the number of sort operations that have occurred. 7324 ** A non-zero value in this counter may indicate an opportunity to 7325 ** improvement performance through careful use of indices.</dd> 7326 ** 7327 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7328 ** <dd>^This is the number of rows inserted into transient indices that 7329 ** were created automatically in order to help joins run faster. 7330 ** A non-zero value in this counter may indicate an opportunity to 7331 ** improvement performance by adding permanent indices that do not 7332 ** need to be reinitialized each time the statement is run.</dd> 7333 ** 7334 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7335 ** <dd>^This is the number of virtual machine operations executed 7336 ** by the prepared statement if that number is less than or equal 7337 ** to 2147483647. The number of virtual machine operations can be 7338 ** used as a proxy for the total work done by the prepared statement. 7339 ** If the number of virtual machine operations exceeds 2147483647 7340 ** then the value returned by this statement status code is undefined. 7341 ** 7342 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7343 ** <dd>^This is the number of times that the prepare statement has been 7344 ** automatically regenerated due to schema changes or change to 7345 ** [bound parameters] that might affect the query plan. 7346 ** 7347 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7348 ** <dd>^This is the number of times that the prepared statement has 7349 ** been run. A single "run" for the purposes of this counter is one 7350 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7351 ** The counter is incremented on the first [sqlite3_step()] call of each 7352 ** cycle. 7353 ** 7354 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7355 ** <dd>^This is the approximate number of bytes of heap memory 7356 ** used to store the prepared statement. ^This value is not actually 7357 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7358 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7359 ** </dd> 7360 ** </dl> 7361 */ 7362 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7363 #define SQLITE_STMTSTATUS_SORT 2 7364 #define SQLITE_STMTSTATUS_AUTOINDEX 3 7365 #define SQLITE_STMTSTATUS_VM_STEP 4 7366 #define SQLITE_STMTSTATUS_REPREPARE 5 7367 #define SQLITE_STMTSTATUS_RUN 6 7368 #define SQLITE_STMTSTATUS_MEMUSED 99 7369 7370 /* 7371 ** CAPI3REF: Custom Page Cache Object 7372 ** 7373 ** The sqlite3_pcache type is opaque. It is implemented by 7374 ** the pluggable module. The SQLite core has no knowledge of 7375 ** its size or internal structure and never deals with the 7376 ** sqlite3_pcache object except by holding and passing pointers 7377 ** to the object. 7378 ** 7379 ** See [sqlite3_pcache_methods2] for additional information. 7380 */ 7381 typedef struct sqlite3_pcache sqlite3_pcache; 7382 7383 /* 7384 ** CAPI3REF: Custom Page Cache Object 7385 ** 7386 ** The sqlite3_pcache_page object represents a single page in the 7387 ** page cache. The page cache will allocate instances of this 7388 ** object. Various methods of the page cache use pointers to instances 7389 ** of this object as parameters or as their return value. 7390 ** 7391 ** See [sqlite3_pcache_methods2] for additional information. 7392 */ 7393 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7394 struct sqlite3_pcache_page { 7395 void *pBuf; /* The content of the page */ 7396 void *pExtra; /* Extra information associated with the page */ 7397 }; 7398 7399 /* 7400 ** CAPI3REF: Application Defined Page Cache. 7401 ** KEYWORDS: {page cache} 7402 ** 7403 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7404 ** register an alternative page cache implementation by passing in an 7405 ** instance of the sqlite3_pcache_methods2 structure.)^ 7406 ** In many applications, most of the heap memory allocated by 7407 ** SQLite is used for the page cache. 7408 ** By implementing a 7409 ** custom page cache using this API, an application can better control 7410 ** the amount of memory consumed by SQLite, the way in which 7411 ** that memory is allocated and released, and the policies used to 7412 ** determine exactly which parts of a database file are cached and for 7413 ** how long. 7414 ** 7415 ** The alternative page cache mechanism is an 7416 ** extreme measure that is only needed by the most demanding applications. 7417 ** The built-in page cache is recommended for most uses. 7418 ** 7419 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7420 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7421 ** the application may discard the parameter after the call to 7422 ** [sqlite3_config()] returns.)^ 7423 ** 7424 ** [[the xInit() page cache method]] 7425 ** ^(The xInit() method is called once for each effective 7426 ** call to [sqlite3_initialize()])^ 7427 ** (usually only once during the lifetime of the process). ^(The xInit() 7428 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7429 ** The intent of the xInit() method is to set up global data structures 7430 ** required by the custom page cache implementation. 7431 ** ^(If the xInit() method is NULL, then the 7432 ** built-in default page cache is used instead of the application defined 7433 ** page cache.)^ 7434 ** 7435 ** [[the xShutdown() page cache method]] 7436 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7437 ** It can be used to clean up 7438 ** any outstanding resources before process shutdown, if required. 7439 ** ^The xShutdown() method may be NULL. 7440 ** 7441 ** ^SQLite automatically serializes calls to the xInit method, 7442 ** so the xInit method need not be threadsafe. ^The 7443 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 7444 ** not need to be threadsafe either. All other methods must be threadsafe 7445 ** in multithreaded applications. 7446 ** 7447 ** ^SQLite will never invoke xInit() more than once without an intervening 7448 ** call to xShutdown(). 7449 ** 7450 ** [[the xCreate() page cache methods]] 7451 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 7452 ** SQLite will typically create one cache instance for each open database file, 7453 ** though this is not guaranteed. ^The 7454 ** first parameter, szPage, is the size in bytes of the pages that must 7455 ** be allocated by the cache. ^szPage will always a power of two. ^The 7456 ** second parameter szExtra is a number of bytes of extra storage 7457 ** associated with each page cache entry. ^The szExtra parameter will 7458 ** a number less than 250. SQLite will use the 7459 ** extra szExtra bytes on each page to store metadata about the underlying 7460 ** database page on disk. The value passed into szExtra depends 7461 ** on the SQLite version, the target platform, and how SQLite was compiled. 7462 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7463 ** created will be used to cache database pages of a file stored on disk, or 7464 ** false if it is used for an in-memory database. The cache implementation 7465 ** does not have to do anything special based with the value of bPurgeable; 7466 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7467 ** never invoke xUnpin() except to deliberately delete a page. 7468 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7469 ** false will always have the "discard" flag set to true. 7470 ** ^Hence, a cache created with bPurgeable false will 7471 ** never contain any unpinned pages. 7472 ** 7473 ** [[the xCachesize() page cache method]] 7474 ** ^(The xCachesize() method may be called at any time by SQLite to set the 7475 ** suggested maximum cache-size (number of pages stored by) the cache 7476 ** instance passed as the first argument. This is the value configured using 7477 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7478 ** parameter, the implementation is not required to do anything with this 7479 ** value; it is advisory only. 7480 ** 7481 ** [[the xPagecount() page cache methods]] 7482 ** The xPagecount() method must return the number of pages currently 7483 ** stored in the cache, both pinned and unpinned. 7484 ** 7485 ** [[the xFetch() page cache methods]] 7486 ** The xFetch() method locates a page in the cache and returns a pointer to 7487 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7488 ** The pBuf element of the returned sqlite3_pcache_page object will be a 7489 ** pointer to a buffer of szPage bytes used to store the content of a 7490 ** single database page. The pExtra element of sqlite3_pcache_page will be 7491 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 7492 ** for each entry in the page cache. 7493 ** 7494 ** The page to be fetched is determined by the key. ^The minimum key value 7495 ** is 1. After it has been retrieved using xFetch, the page is considered 7496 ** to be "pinned". 7497 ** 7498 ** If the requested page is already in the page cache, then the page cache 7499 ** implementation must return a pointer to the page buffer with its content 7500 ** intact. If the requested page is not already in the cache, then the 7501 ** cache implementation should use the value of the createFlag 7502 ** parameter to help it determined what action to take: 7503 ** 7504 ** <table border=1 width=85% align=center> 7505 ** <tr><th> createFlag <th> Behavior when page is not already in cache 7506 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7507 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7508 ** Otherwise return NULL. 7509 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7510 ** NULL if allocating a new page is effectively impossible. 7511 ** </table> 7512 ** 7513 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7514 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 7515 ** failed.)^ In between the to xFetch() calls, SQLite may 7516 ** attempt to unpin one or more cache pages by spilling the content of 7517 ** pinned pages to disk and synching the operating system disk cache. 7518 ** 7519 ** [[the xUnpin() page cache method]] 7520 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7521 ** as its second argument. If the third parameter, discard, is non-zero, 7522 ** then the page must be evicted from the cache. 7523 ** ^If the discard parameter is 7524 ** zero, then the page may be discarded or retained at the discretion of 7525 ** page cache implementation. ^The page cache implementation 7526 ** may choose to evict unpinned pages at any time. 7527 ** 7528 ** The cache must not perform any reference counting. A single 7529 ** call to xUnpin() unpins the page regardless of the number of prior calls 7530 ** to xFetch(). 7531 ** 7532 ** [[the xRekey() page cache methods]] 7533 ** The xRekey() method is used to change the key value associated with the 7534 ** page passed as the second argument. If the cache 7535 ** previously contains an entry associated with newKey, it must be 7536 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7537 ** to be pinned. 7538 ** 7539 ** When SQLite calls the xTruncate() method, the cache must discard all 7540 ** existing cache entries with page numbers (keys) greater than or equal 7541 ** to the value of the iLimit parameter passed to xTruncate(). If any 7542 ** of these pages are pinned, they are implicitly unpinned, meaning that 7543 ** they can be safely discarded. 7544 ** 7545 ** [[the xDestroy() page cache method]] 7546 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7547 ** All resources associated with the specified cache should be freed. ^After 7548 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7549 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7550 ** functions. 7551 ** 7552 ** [[the xShrink() page cache method]] 7553 ** ^SQLite invokes the xShrink() method when it wants the page cache to 7554 ** free up as much of heap memory as possible. The page cache implementation 7555 ** is not obligated to free any memory, but well-behaved implementations should 7556 ** do their best. 7557 */ 7558 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7559 struct sqlite3_pcache_methods2 { 7560 int iVersion; 7561 void *pArg; 7562 int (*xInit)(void*); 7563 void (*xShutdown)(void*); 7564 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7565 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7566 int (*xPagecount)(sqlite3_pcache*); 7567 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7568 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7569 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7570 unsigned oldKey, unsigned newKey); 7571 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7572 void (*xDestroy)(sqlite3_pcache*); 7573 void (*xShrink)(sqlite3_pcache*); 7574 }; 7575 7576 /* 7577 ** This is the obsolete pcache_methods object that has now been replaced 7578 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7579 ** retained in the header file for backwards compatibility only. 7580 */ 7581 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7582 struct sqlite3_pcache_methods { 7583 void *pArg; 7584 int (*xInit)(void*); 7585 void (*xShutdown)(void*); 7586 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7587 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7588 int (*xPagecount)(sqlite3_pcache*); 7589 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7590 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7591 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7592 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7593 void (*xDestroy)(sqlite3_pcache*); 7594 }; 7595 7596 7597 /* 7598 ** CAPI3REF: Online Backup Object 7599 ** 7600 ** The sqlite3_backup object records state information about an ongoing 7601 ** online backup operation. ^The sqlite3_backup object is created by 7602 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 7603 ** [sqlite3_backup_finish()]. 7604 ** 7605 ** See Also: [Using the SQLite Online Backup API] 7606 */ 7607 typedef struct sqlite3_backup sqlite3_backup; 7608 7609 /* 7610 ** CAPI3REF: Online Backup API. 7611 ** 7612 ** The backup API copies the content of one database into another. 7613 ** It is useful either for creating backups of databases or 7614 ** for copying in-memory databases to or from persistent files. 7615 ** 7616 ** See Also: [Using the SQLite Online Backup API] 7617 ** 7618 ** ^SQLite holds a write transaction open on the destination database file 7619 ** for the duration of the backup operation. 7620 ** ^The source database is read-locked only while it is being read; 7621 ** it is not locked continuously for the entire backup operation. 7622 ** ^Thus, the backup may be performed on a live source database without 7623 ** preventing other database connections from 7624 ** reading or writing to the source database while the backup is underway. 7625 ** 7626 ** ^(To perform a backup operation: 7627 ** <ol> 7628 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7629 ** backup, 7630 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7631 ** the data between the two databases, and finally 7632 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7633 ** associated with the backup operation. 7634 ** </ol>)^ 7635 ** There should be exactly one call to sqlite3_backup_finish() for each 7636 ** successful call to sqlite3_backup_init(). 7637 ** 7638 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7639 ** 7640 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7641 ** [database connection] associated with the destination database 7642 ** and the database name, respectively. 7643 ** ^The database name is "main" for the main database, "temp" for the 7644 ** temporary database, or the name specified after the AS keyword in 7645 ** an [ATTACH] statement for an attached database. 7646 ** ^The S and M arguments passed to 7647 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7648 ** and database name of the source database, respectively. 7649 ** ^The source and destination [database connections] (parameters S and D) 7650 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7651 ** an error. 7652 ** 7653 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7654 ** there is already a read or read-write transaction open on the 7655 ** destination database. 7656 ** 7657 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7658 ** returned and an error code and error message are stored in the 7659 ** destination [database connection] D. 7660 ** ^The error code and message for the failed call to sqlite3_backup_init() 7661 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7662 ** [sqlite3_errmsg16()] functions. 7663 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 7664 ** [sqlite3_backup] object. 7665 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7666 ** sqlite3_backup_finish() functions to perform the specified backup 7667 ** operation. 7668 ** 7669 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7670 ** 7671 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7672 ** the source and destination databases specified by [sqlite3_backup] object B. 7673 ** ^If N is negative, all remaining source pages are copied. 7674 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7675 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 7676 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7677 ** from source to destination, then it returns [SQLITE_DONE]. 7678 ** ^If an error occurs while running sqlite3_backup_step(B,N), 7679 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 7680 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7681 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7682 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7683 ** 7684 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7685 ** <ol> 7686 ** <li> the destination database was opened read-only, or 7687 ** <li> the destination database is using write-ahead-log journaling 7688 ** and the destination and source page sizes differ, or 7689 ** <li> the destination database is an in-memory database and the 7690 ** destination and source page sizes differ. 7691 ** </ol>)^ 7692 ** 7693 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7694 ** the [sqlite3_busy_handler | busy-handler function] 7695 ** is invoked (if one is specified). ^If the 7696 ** busy-handler returns non-zero before the lock is available, then 7697 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7698 ** sqlite3_backup_step() can be retried later. ^If the source 7699 ** [database connection] 7700 ** is being used to write to the source database when sqlite3_backup_step() 7701 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7702 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 7703 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7704 ** [SQLITE_READONLY] is returned, then 7705 ** there is no point in retrying the call to sqlite3_backup_step(). These 7706 ** errors are considered fatal.)^ The application must accept 7707 ** that the backup operation has failed and pass the backup operation handle 7708 ** to the sqlite3_backup_finish() to release associated resources. 7709 ** 7710 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7711 ** on the destination file. ^The exclusive lock is not released until either 7712 ** sqlite3_backup_finish() is called or the backup operation is complete 7713 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7714 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 7715 ** lasts for the duration of the sqlite3_backup_step() call. 7716 ** ^Because the source database is not locked between calls to 7717 ** sqlite3_backup_step(), the source database may be modified mid-way 7718 ** through the backup process. ^If the source database is modified by an 7719 ** external process or via a database connection other than the one being 7720 ** used by the backup operation, then the backup will be automatically 7721 ** restarted by the next call to sqlite3_backup_step(). ^If the source 7722 ** database is modified by the using the same database connection as is used 7723 ** by the backup operation, then the backup database is automatically 7724 ** updated at the same time. 7725 ** 7726 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7727 ** 7728 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7729 ** application wishes to abandon the backup operation, the application 7730 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7731 ** ^The sqlite3_backup_finish() interfaces releases all 7732 ** resources associated with the [sqlite3_backup] object. 7733 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7734 ** active write-transaction on the destination database is rolled back. 7735 ** The [sqlite3_backup] object is invalid 7736 ** and may not be used following a call to sqlite3_backup_finish(). 7737 ** 7738 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7739 ** sqlite3_backup_step() errors occurred, regardless or whether or not 7740 ** sqlite3_backup_step() completed. 7741 ** ^If an out-of-memory condition or IO error occurred during any prior 7742 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7743 ** sqlite3_backup_finish() returns the corresponding [error code]. 7744 ** 7745 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7746 ** is not a permanent error and does not affect the return value of 7747 ** sqlite3_backup_finish(). 7748 ** 7749 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7750 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7751 ** 7752 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7753 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7754 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7755 ** in the source database at the conclusion of the most recent 7756 ** sqlite3_backup_step(). 7757 ** ^(The values returned by these functions are only updated by 7758 ** sqlite3_backup_step(). If the source database is modified in a way that 7759 ** changes the size of the source database or the number of pages remaining, 7760 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7761 ** and sqlite3_backup_remaining() until after the next 7762 ** sqlite3_backup_step().)^ 7763 ** 7764 ** <b>Concurrent Usage of Database Handles</b> 7765 ** 7766 ** ^The source [database connection] may be used by the application for other 7767 ** purposes while a backup operation is underway or being initialized. 7768 ** ^If SQLite is compiled and configured to support threadsafe database 7769 ** connections, then the source database connection may be used concurrently 7770 ** from within other threads. 7771 ** 7772 ** However, the application must guarantee that the destination 7773 ** [database connection] is not passed to any other API (by any thread) after 7774 ** sqlite3_backup_init() is called and before the corresponding call to 7775 ** sqlite3_backup_finish(). SQLite does not currently check to see 7776 ** if the application incorrectly accesses the destination [database connection] 7777 ** and so no error code is reported, but the operations may malfunction 7778 ** nevertheless. Use of the destination database connection while a 7779 ** backup is in progress might also also cause a mutex deadlock. 7780 ** 7781 ** If running in [shared cache mode], the application must 7782 ** guarantee that the shared cache used by the destination database 7783 ** is not accessed while the backup is running. In practice this means 7784 ** that the application must guarantee that the disk file being 7785 ** backed up to is not accessed by any connection within the process, 7786 ** not just the specific connection that was passed to sqlite3_backup_init(). 7787 ** 7788 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7789 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7790 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7791 ** APIs are not strictly speaking threadsafe. If they are invoked at the 7792 ** same time as another thread is invoking sqlite3_backup_step() it is 7793 ** possible that they return invalid values. 7794 */ 7795 SQLITE_API sqlite3_backup *sqlite3_backup_init( 7796 sqlite3 *pDest, /* Destination database handle */ 7797 const char *zDestName, /* Destination database name */ 7798 sqlite3 *pSource, /* Source database handle */ 7799 const char *zSourceName /* Source database name */ 7800 ); 7801 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7802 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 7803 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 7804 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 7805 7806 /* 7807 ** CAPI3REF: Unlock Notification 7808 ** METHOD: sqlite3 7809 ** 7810 ** ^When running in shared-cache mode, a database operation may fail with 7811 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7812 ** individual tables within the shared-cache cannot be obtained. See 7813 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7814 ** ^This API may be used to register a callback that SQLite will invoke 7815 ** when the connection currently holding the required lock relinquishes it. 7816 ** ^This API is only available if the library was compiled with the 7817 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7818 ** 7819 ** See Also: [Using the SQLite Unlock Notification Feature]. 7820 ** 7821 ** ^Shared-cache locks are released when a database connection concludes 7822 ** its current transaction, either by committing it or rolling it back. 7823 ** 7824 ** ^When a connection (known as the blocked connection) fails to obtain a 7825 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7826 ** identity of the database connection (the blocking connection) that 7827 ** has locked the required resource is stored internally. ^After an 7828 ** application receives an SQLITE_LOCKED error, it may call the 7829 ** sqlite3_unlock_notify() method with the blocked connection handle as 7830 ** the first argument to register for a callback that will be invoked 7831 ** when the blocking connections current transaction is concluded. ^The 7832 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7833 ** call that concludes the blocking connections transaction. 7834 ** 7835 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7836 ** there is a chance that the blocking connection will have already 7837 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7838 ** If this happens, then the specified callback is invoked immediately, 7839 ** from within the call to sqlite3_unlock_notify().)^ 7840 ** 7841 ** ^If the blocked connection is attempting to obtain a write-lock on a 7842 ** shared-cache table, and more than one other connection currently holds 7843 ** a read-lock on the same table, then SQLite arbitrarily selects one of 7844 ** the other connections to use as the blocking connection. 7845 ** 7846 ** ^(There may be at most one unlock-notify callback registered by a 7847 ** blocked connection. If sqlite3_unlock_notify() is called when the 7848 ** blocked connection already has a registered unlock-notify callback, 7849 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7850 ** called with a NULL pointer as its second argument, then any existing 7851 ** unlock-notify callback is canceled. ^The blocked connections 7852 ** unlock-notify callback may also be canceled by closing the blocked 7853 ** connection using [sqlite3_close()]. 7854 ** 7855 ** The unlock-notify callback is not reentrant. If an application invokes 7856 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7857 ** crash or deadlock may be the result. 7858 ** 7859 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7860 ** returns SQLITE_OK. 7861 ** 7862 ** <b>Callback Invocation Details</b> 7863 ** 7864 ** When an unlock-notify callback is registered, the application provides a 7865 ** single void* pointer that is passed to the callback when it is invoked. 7866 ** However, the signature of the callback function allows SQLite to pass 7867 ** it an array of void* context pointers. The first argument passed to 7868 ** an unlock-notify callback is a pointer to an array of void* pointers, 7869 ** and the second is the number of entries in the array. 7870 ** 7871 ** When a blocking connections transaction is concluded, there may be 7872 ** more than one blocked connection that has registered for an unlock-notify 7873 ** callback. ^If two or more such blocked connections have specified the 7874 ** same callback function, then instead of invoking the callback function 7875 ** multiple times, it is invoked once with the set of void* context pointers 7876 ** specified by the blocked connections bundled together into an array. 7877 ** This gives the application an opportunity to prioritize any actions 7878 ** related to the set of unblocked database connections. 7879 ** 7880 ** <b>Deadlock Detection</b> 7881 ** 7882 ** Assuming that after registering for an unlock-notify callback a 7883 ** database waits for the callback to be issued before taking any further 7884 ** action (a reasonable assumption), then using this API may cause the 7885 ** application to deadlock. For example, if connection X is waiting for 7886 ** connection Y's transaction to be concluded, and similarly connection 7887 ** Y is waiting on connection X's transaction, then neither connection 7888 ** will proceed and the system may remain deadlocked indefinitely. 7889 ** 7890 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7891 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7892 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7893 ** unlock-notify callback is registered. The system is said to be in 7894 ** a deadlocked state if connection A has registered for an unlock-notify 7895 ** callback on the conclusion of connection B's transaction, and connection 7896 ** B has itself registered for an unlock-notify callback when connection 7897 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7898 ** the system is also considered to be deadlocked if connection B has 7899 ** registered for an unlock-notify callback on the conclusion of connection 7900 ** C's transaction, where connection C is waiting on connection A. ^Any 7901 ** number of levels of indirection are allowed. 7902 ** 7903 ** <b>The "DROP TABLE" Exception</b> 7904 ** 7905 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7906 ** always appropriate to call sqlite3_unlock_notify(). There is however, 7907 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7908 ** SQLite checks if there are any currently executing SELECT statements 7909 ** that belong to the same connection. If there are, SQLITE_LOCKED is 7910 ** returned. In this case there is no "blocking connection", so invoking 7911 ** sqlite3_unlock_notify() results in the unlock-notify callback being 7912 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7913 ** or "DROP INDEX" query, an infinite loop might be the result. 7914 ** 7915 ** One way around this problem is to check the extended error code returned 7916 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7917 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7918 ** the special "DROP TABLE/INDEX" case, the extended error code is just 7919 ** SQLITE_LOCKED.)^ 7920 */ 7921 SQLITE_API int sqlite3_unlock_notify( 7922 sqlite3 *pBlocked, /* Waiting connection */ 7923 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7924 void *pNotifyArg /* Argument to pass to xNotify */ 7925 ); 7926 7927 7928 /* 7929 ** CAPI3REF: String Comparison 7930 ** 7931 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7932 ** and extensions to compare the contents of two buffers containing UTF-8 7933 ** strings in a case-independent fashion, using the same definition of "case 7934 ** independence" that SQLite uses internally when comparing identifiers. 7935 */ 7936 SQLITE_API int sqlite3_stricmp(const char *, const char *); 7937 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 7938 7939 /* 7940 ** CAPI3REF: String Globbing 7941 * 7942 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7943 ** string X matches the [GLOB] pattern P. 7944 ** ^The definition of [GLOB] pattern matching used in 7945 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7946 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7947 ** is case sensitive. 7948 ** 7949 ** Note that this routine returns zero on a match and non-zero if the strings 7950 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7951 ** 7952 ** See also: [sqlite3_strlike()]. 7953 */ 7954 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 7955 7956 /* 7957 ** CAPI3REF: String LIKE Matching 7958 * 7959 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7960 ** string X matches the [LIKE] pattern P with escape character E. 7961 ** ^The definition of [LIKE] pattern matching used in 7962 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7963 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7964 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7965 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7966 ** insensitive - equivalent upper and lower case ASCII characters match 7967 ** one another. 7968 ** 7969 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7970 ** only ASCII characters are case folded. 7971 ** 7972 ** Note that this routine returns zero on a match and non-zero if the strings 7973 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7974 ** 7975 ** See also: [sqlite3_strglob()]. 7976 */ 7977 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7978 7979 /* 7980 ** CAPI3REF: Error Logging Interface 7981 ** 7982 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7983 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7984 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7985 ** used with [sqlite3_snprintf()] to generate the final output string. 7986 ** 7987 ** The sqlite3_log() interface is intended for use by extensions such as 7988 ** virtual tables, collating functions, and SQL functions. While there is 7989 ** nothing to prevent an application from calling sqlite3_log(), doing so 7990 ** is considered bad form. 7991 ** 7992 ** The zFormat string must not be NULL. 7993 ** 7994 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7995 ** will not use dynamically allocated memory. The log message is stored in 7996 ** a fixed-length buffer on the stack. If the log message is longer than 7997 ** a few hundred characters, it will be truncated to the length of the 7998 ** buffer. 7999 */ 8000 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8001 8002 /* 8003 ** CAPI3REF: Write-Ahead Log Commit Hook 8004 ** METHOD: sqlite3 8005 ** 8006 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8007 ** is invoked each time data is committed to a database in wal mode. 8008 ** 8009 ** ^(The callback is invoked by SQLite after the commit has taken place and 8010 ** the associated write-lock on the database released)^, so the implementation 8011 ** may read, write or [checkpoint] the database as required. 8012 ** 8013 ** ^The first parameter passed to the callback function when it is invoked 8014 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8015 ** registering the callback. ^The second is a copy of the database handle. 8016 ** ^The third parameter is the name of the database that was written to - 8017 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8018 ** is the number of pages currently in the write-ahead log file, 8019 ** including those that were just committed. 8020 ** 8021 ** The callback function should normally return [SQLITE_OK]. ^If an error 8022 ** code is returned, that error will propagate back up through the 8023 ** SQLite code base to cause the statement that provoked the callback 8024 ** to report an error, though the commit will have still occurred. If the 8025 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8026 ** that does not correspond to any valid SQLite error code, the results 8027 ** are undefined. 8028 ** 8029 ** A single database handle may have at most a single write-ahead log callback 8030 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8031 ** previously registered write-ahead log callback. ^Note that the 8032 ** [sqlite3_wal_autocheckpoint()] interface and the 8033 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8034 ** overwrite any prior [sqlite3_wal_hook()] settings. 8035 */ 8036 SQLITE_API void *sqlite3_wal_hook( 8037 sqlite3*, 8038 int(*)(void *,sqlite3*,const char*,int), 8039 void* 8040 ); 8041 8042 /* 8043 ** CAPI3REF: Configure an auto-checkpoint 8044 ** METHOD: sqlite3 8045 ** 8046 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8047 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8048 ** to automatically [checkpoint] 8049 ** after committing a transaction if there are N or 8050 ** more frames in the [write-ahead log] file. ^Passing zero or 8051 ** a negative value as the nFrame parameter disables automatic 8052 ** checkpoints entirely. 8053 ** 8054 ** ^The callback registered by this function replaces any existing callback 8055 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8056 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8057 ** configured by this function. 8058 ** 8059 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8060 ** from SQL. 8061 ** 8062 ** ^Checkpoints initiated by this mechanism are 8063 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8064 ** 8065 ** ^Every new [database connection] defaults to having the auto-checkpoint 8066 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8067 ** pages. The use of this interface 8068 ** is only necessary if the default setting is found to be suboptimal 8069 ** for a particular application. 8070 */ 8071 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8072 8073 /* 8074 ** CAPI3REF: Checkpoint a database 8075 ** METHOD: sqlite3 8076 ** 8077 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8078 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8079 ** 8080 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8081 ** [write-ahead log] for database X on [database connection] D to be 8082 ** transferred into the database file and for the write-ahead log to 8083 ** be reset. See the [checkpointing] documentation for addition 8084 ** information. 8085 ** 8086 ** This interface used to be the only way to cause a checkpoint to 8087 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8088 ** interface was added. This interface is retained for backwards 8089 ** compatibility and as a convenience for applications that need to manually 8090 ** start a callback but which do not need the full power (and corresponding 8091 ** complication) of [sqlite3_wal_checkpoint_v2()]. 8092 */ 8093 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8094 8095 /* 8096 ** CAPI3REF: Checkpoint a database 8097 ** METHOD: sqlite3 8098 ** 8099 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8100 ** operation on database X of [database connection] D in mode M. Status 8101 ** information is written back into integers pointed to by L and C.)^ 8102 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 8103 ** 8104 ** <dl> 8105 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8106 ** ^Checkpoint as many frames as possible without waiting for any database 8107 ** readers or writers to finish, then sync the database file if all frames 8108 ** in the log were checkpointed. ^The [busy-handler callback] 8109 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8110 ** ^On the other hand, passive mode might leave the checkpoint unfinished 8111 ** if there are concurrent readers or writers. 8112 ** 8113 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 8114 ** ^This mode blocks (it invokes the 8115 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 8116 ** database writer and all readers are reading from the most recent database 8117 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 8118 ** database file. ^This mode blocks new database writers while it is pending, 8119 ** but new database readers are allowed to continue unimpeded. 8120 ** 8121 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8122 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8123 ** that after checkpointing the log file it blocks (calls the 8124 ** [busy-handler callback]) 8125 ** until all readers are reading from the database file only. ^This ensures 8126 ** that the next writer will restart the log file from the beginning. 8127 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8128 ** database writer attempts while it is pending, but does not impede readers. 8129 ** 8130 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8131 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8132 ** addition that it also truncates the log file to zero bytes just prior 8133 ** to a successful return. 8134 ** </dl> 8135 ** 8136 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8137 ** the log file or to -1 if the checkpoint could not run because 8138 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8139 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8140 ** log file (including any that were already checkpointed before the function 8141 ** was called) or to -1 if the checkpoint could not run due to an error or 8142 ** because the database is not in WAL mode. ^Note that upon successful 8143 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8144 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8145 ** 8146 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8147 ** any other process is running a checkpoint operation at the same time, the 8148 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8149 ** busy-handler configured, it will not be invoked in this case. 8150 ** 8151 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8152 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8153 ** obtained immediately, and a busy-handler is configured, it is invoked and 8154 ** the writer lock retried until either the busy-handler returns 0 or the lock 8155 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 8156 ** database readers as described above. ^If the busy-handler returns 0 before 8157 ** the writer lock is obtained or while waiting for database readers, the 8158 ** checkpoint operation proceeds from that point in the same way as 8159 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8160 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 8161 ** 8162 ** ^If parameter zDb is NULL or points to a zero length string, then the 8163 ** specified operation is attempted on all WAL databases [attached] to 8164 ** [database connection] db. In this case the 8165 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8166 ** an SQLITE_BUSY error is encountered when processing one or more of the 8167 ** attached WAL databases, the operation is still attempted on any remaining 8168 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8169 ** error occurs while processing an attached database, processing is abandoned 8170 ** and the error code is returned to the caller immediately. ^If no error 8171 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8172 ** databases, SQLITE_OK is returned. 8173 ** 8174 ** ^If database zDb is the name of an attached database that is not in WAL 8175 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8176 ** zDb is not NULL (or a zero length string) and is not the name of any 8177 ** attached database, SQLITE_ERROR is returned to the caller. 8178 ** 8179 ** ^Unless it returns SQLITE_MISUSE, 8180 ** the sqlite3_wal_checkpoint_v2() interface 8181 ** sets the error information that is queried by 8182 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8183 ** 8184 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8185 ** from SQL. 8186 */ 8187 SQLITE_API int sqlite3_wal_checkpoint_v2( 8188 sqlite3 *db, /* Database handle */ 8189 const char *zDb, /* Name of attached database (or NULL) */ 8190 int eMode, /* SQLITE_CHECKPOINT_* value */ 8191 int *pnLog, /* OUT: Size of WAL log in frames */ 8192 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8193 ); 8194 8195 /* 8196 ** CAPI3REF: Checkpoint Mode Values 8197 ** KEYWORDS: {checkpoint mode} 8198 ** 8199 ** These constants define all valid values for the "checkpoint mode" passed 8200 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8201 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8202 ** meaning of each of these checkpoint modes. 8203 */ 8204 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8205 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8206 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8207 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8208 8209 /* 8210 ** CAPI3REF: Virtual Table Interface Configuration 8211 ** 8212 ** This function may be called by either the [xConnect] or [xCreate] method 8213 ** of a [virtual table] implementation to configure 8214 ** various facets of the virtual table interface. 8215 ** 8216 ** If this interface is invoked outside the context of an xConnect or 8217 ** xCreate virtual table method then the behavior is undefined. 8218 ** 8219 ** At present, there is only one option that may be configured using 8220 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8221 ** may be added in the future. 8222 */ 8223 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 8224 8225 /* 8226 ** CAPI3REF: Virtual Table Configuration Options 8227 ** 8228 ** These macros define the various options to the 8229 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 8230 ** can use to customize and optimize their behavior. 8231 ** 8232 ** <dl> 8233 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8234 ** <dd>Calls of the form 8235 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8236 ** where X is an integer. If X is zero, then the [virtual table] whose 8237 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8238 ** support constraints. In this configuration (which is the default) if 8239 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8240 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8241 ** specified as part of the users SQL statement, regardless of the actual 8242 ** ON CONFLICT mode specified. 8243 ** 8244 ** If X is non-zero, then the virtual table implementation guarantees 8245 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8246 ** any modifications to internal or persistent data structures have been made. 8247 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8248 ** is able to roll back a statement or database transaction, and abandon 8249 ** or continue processing the current SQL statement as appropriate. 8250 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8251 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8252 ** had been ABORT. 8253 ** 8254 ** Virtual table implementations that are required to handle OR REPLACE 8255 ** must do so within the [xUpdate] method. If a call to the 8256 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8257 ** CONFLICT policy is REPLACE, the virtual table implementation should 8258 ** silently replace the appropriate rows within the xUpdate callback and 8259 ** return SQLITE_OK. Or, if this is not possible, it may return 8260 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8261 ** constraint handling. 8262 ** </dl> 8263 */ 8264 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8265 8266 /* 8267 ** CAPI3REF: Determine The Virtual Table Conflict Policy 8268 ** 8269 ** This function may only be called from within a call to the [xUpdate] method 8270 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8271 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8272 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8273 ** of the SQL statement that triggered the call to the [xUpdate] method of the 8274 ** [virtual table]. 8275 */ 8276 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8277 8278 /* 8279 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8280 ** 8281 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8282 ** method of a [virtual table], then it returns true if and only if the 8283 ** column is being fetched as part of an UPDATE operation during which the 8284 ** column value will not change. Applications might use this to substitute 8285 ** a lighter-weight value to return that the corresponding [xUpdate] method 8286 ** understands as a "no-change" value. 8287 ** 8288 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8289 ** the column is not changed by the UPDATE statement, they the xColumn 8290 ** method can optionally return without setting a result, without calling 8291 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8292 ** In that case, [sqlite3_value_nochange(X)] will return true for the 8293 ** same column in the [xUpdate] method. 8294 */ 8295 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 8296 8297 /* 8298 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8299 ** 8300 ** This function may only be called from within a call to the [xBestIndex] 8301 ** method of a [virtual table]. 8302 ** 8303 ** The first argument must be the sqlite3_index_info object that is the 8304 ** first parameter to the xBestIndex() method. The second argument must be 8305 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 8306 ** structure passed to xBestIndex. This function returns a pointer to a buffer 8307 ** containing the name of the collation sequence for the corresponding 8308 ** constraint. 8309 */ 8310 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8311 8312 /* 8313 ** CAPI3REF: Conflict resolution modes 8314 ** KEYWORDS: {conflict resolution mode} 8315 ** 8316 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 8317 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 8318 ** is for the SQL statement being evaluated. 8319 ** 8320 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 8321 ** return value from the [sqlite3_set_authorizer()] callback and that 8322 ** [SQLITE_ABORT] is also a [result code]. 8323 */ 8324 #define SQLITE_ROLLBACK 1 8325 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8326 #define SQLITE_FAIL 3 8327 /* #define SQLITE_ABORT 4 // Also an error code */ 8328 #define SQLITE_REPLACE 5 8329 8330 /* 8331 ** CAPI3REF: Prepared Statement Scan Status Opcodes 8332 ** KEYWORDS: {scanstatus options} 8333 ** 8334 ** The following constants can be used for the T parameter to the 8335 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8336 ** different metric for sqlite3_stmt_scanstatus() to return. 8337 ** 8338 ** When the value returned to V is a string, space to hold that string is 8339 ** managed by the prepared statement S and will be automatically freed when 8340 ** S is finalized. 8341 ** 8342 ** <dl> 8343 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8344 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8345 ** set to the total number of times that the X-th loop has run.</dd> 8346 ** 8347 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8348 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8349 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 8350 ** 8351 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8352 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 8353 ** query planner's estimate for the average number of rows output from each 8354 ** iteration of the X-th loop. If the query planner's estimates was accurate, 8355 ** then this value will approximate the quotient NVISIT/NLOOP and the 8356 ** product of this value for all prior loops with the same SELECTID will 8357 ** be the NLOOP value for the current loop. 8358 ** 8359 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8360 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8361 ** to a zero-terminated UTF-8 string containing the name of the index or table 8362 ** used for the X-th loop. 8363 ** 8364 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8365 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8366 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8367 ** description for the X-th loop. 8368 ** 8369 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8370 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8371 ** "select-id" for the X-th loop. The select-id identifies which query or 8372 ** subquery the loop is part of. The main query has a select-id of zero. 8373 ** The select-id is the same value as is output in the first column 8374 ** of an [EXPLAIN QUERY PLAN] query. 8375 ** </dl> 8376 */ 8377 #define SQLITE_SCANSTAT_NLOOP 0 8378 #define SQLITE_SCANSTAT_NVISIT 1 8379 #define SQLITE_SCANSTAT_EST 2 8380 #define SQLITE_SCANSTAT_NAME 3 8381 #define SQLITE_SCANSTAT_EXPLAIN 4 8382 #define SQLITE_SCANSTAT_SELECTID 5 8383 8384 /* 8385 ** CAPI3REF: Prepared Statement Scan Status 8386 ** METHOD: sqlite3_stmt 8387 ** 8388 ** This interface returns information about the predicted and measured 8389 ** performance for pStmt. Advanced applications can use this 8390 ** interface to compare the predicted and the measured performance and 8391 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8392 ** 8393 ** Since this interface is expected to be rarely used, it is only 8394 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8395 ** compile-time option. 8396 ** 8397 ** The "iScanStatusOp" parameter determines which status information to return. 8398 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8399 ** of this interface is undefined. 8400 ** ^The requested measurement is written into a variable pointed to by 8401 ** the "pOut" parameter. 8402 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8403 ** Loops are numbered starting from zero. ^If idx is out of range - less than 8404 ** zero or greater than or equal to the total number of loops used to implement 8405 ** the statement - a non-zero value is returned and the variable that pOut 8406 ** points to is unchanged. 8407 ** 8408 ** ^Statistics might not be available for all loops in all statements. ^In cases 8409 ** where there exist loops with no available statistics, this function behaves 8410 ** as if the loop did not exist - it returns non-zero and leave the variable 8411 ** that pOut points to unchanged. 8412 ** 8413 ** See also: [sqlite3_stmt_scanstatus_reset()] 8414 */ 8415 SQLITE_API int sqlite3_stmt_scanstatus( 8416 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8417 int idx, /* Index of loop to report on */ 8418 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8419 void *pOut /* Result written here */ 8420 ); 8421 8422 /* 8423 ** CAPI3REF: Zero Scan-Status Counters 8424 ** METHOD: sqlite3_stmt 8425 ** 8426 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8427 ** 8428 ** This API is only available if the library is built with pre-processor 8429 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8430 */ 8431 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8432 8433 /* 8434 ** CAPI3REF: Flush caches to disk mid-transaction 8435 ** 8436 ** ^If a write-transaction is open on [database connection] D when the 8437 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8438 ** pages in the pager-cache that are not currently in use are written out 8439 ** to disk. A dirty page may be in use if a database cursor created by an 8440 ** active SQL statement is reading from it, or if it is page 1 of a database 8441 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8442 ** interface flushes caches for all schemas - "main", "temp", and 8443 ** any [attached] databases. 8444 ** 8445 ** ^If this function needs to obtain extra database locks before dirty pages 8446 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 8447 ** immediately and there is a busy-handler callback configured, it is invoked 8448 ** in the usual manner. ^If the required lock still cannot be obtained, then 8449 ** the database is skipped and an attempt made to flush any dirty pages 8450 ** belonging to the next (if any) database. ^If any databases are skipped 8451 ** because locks cannot be obtained, but no other error occurs, this 8452 ** function returns SQLITE_BUSY. 8453 ** 8454 ** ^If any other error occurs while flushing dirty pages to disk (for 8455 ** example an IO error or out-of-memory condition), then processing is 8456 ** abandoned and an SQLite [error code] is returned to the caller immediately. 8457 ** 8458 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8459 ** 8460 ** ^This function does not set the database handle error code or message 8461 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8462 */ 8463 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8464 8465 /* 8466 ** CAPI3REF: The pre-update hook. 8467 ** 8468 ** ^These interfaces are only available if SQLite is compiled using the 8469 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8470 ** 8471 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8472 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8473 ** on a database table. 8474 ** ^At most one preupdate hook may be registered at a time on a single 8475 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8476 ** the previous setting. 8477 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8478 ** with a NULL pointer as the second parameter. 8479 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8480 ** the first parameter to callbacks. 8481 ** 8482 ** ^The preupdate hook only fires for changes to real database tables; the 8483 ** preupdate hook is not invoked for changes to [virtual tables] or to 8484 ** system tables like sqlite_master or sqlite_stat1. 8485 ** 8486 ** ^The second parameter to the preupdate callback is a pointer to 8487 ** the [database connection] that registered the preupdate hook. 8488 ** ^The third parameter to the preupdate callback is one of the constants 8489 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8490 ** kind of update operation that is about to occur. 8491 ** ^(The fourth parameter to the preupdate callback is the name of the 8492 ** database within the database connection that is being modified. This 8493 ** will be "main" for the main database or "temp" for TEMP tables or 8494 ** the name given after the AS keyword in the [ATTACH] statement for attached 8495 ** databases.)^ 8496 ** ^The fifth parameter to the preupdate callback is the name of the 8497 ** table that is being modified. 8498 ** 8499 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 8500 ** parameter passed to the preupdate callback is the initial [rowid] of the 8501 ** row being modified or deleted. For an INSERT operation on a rowid table, 8502 ** or any operation on a WITHOUT ROWID table, the value of the sixth 8503 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8504 ** seventh parameter is the final rowid value of the row being inserted 8505 ** or updated. The value of the seventh parameter passed to the callback 8506 ** function is not defined for operations on WITHOUT ROWID tables, or for 8507 ** INSERT operations on rowid tables. 8508 ** 8509 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8510 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8511 ** provide additional information about a preupdate event. These routines 8512 ** may only be called from within a preupdate callback. Invoking any of 8513 ** these routines from outside of a preupdate callback or with a 8514 ** [database connection] pointer that is different from the one supplied 8515 ** to the preupdate callback results in undefined and probably undesirable 8516 ** behavior. 8517 ** 8518 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8519 ** in the row that is being inserted, updated, or deleted. 8520 ** 8521 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8522 ** a [protected sqlite3_value] that contains the value of the Nth column of 8523 ** the table row before it is updated. The N parameter must be between 0 8524 ** and one less than the number of columns or the behavior will be 8525 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8526 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8527 ** behavior is undefined. The [sqlite3_value] that P points to 8528 ** will be destroyed when the preupdate callback returns. 8529 ** 8530 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8531 ** a [protected sqlite3_value] that contains the value of the Nth column of 8532 ** the table row after it is updated. The N parameter must be between 0 8533 ** and one less than the number of columns or the behavior will be 8534 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8535 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8536 ** behavior is undefined. The [sqlite3_value] that P points to 8537 ** will be destroyed when the preupdate callback returns. 8538 ** 8539 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8540 ** callback was invoked as a result of a direct insert, update, or delete 8541 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 8542 ** triggers; or 2 for changes resulting from triggers called by top-level 8543 ** triggers; and so forth. 8544 ** 8545 ** See also: [sqlite3_update_hook()] 8546 */ 8547 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8548 SQLITE_API void *sqlite3_preupdate_hook( 8549 sqlite3 *db, 8550 void(*xPreUpdate)( 8551 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8552 sqlite3 *db, /* Database handle */ 8553 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8554 char const *zDb, /* Database name */ 8555 char const *zName, /* Table name */ 8556 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8557 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8558 ), 8559 void* 8560 ); 8561 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8562 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 8563 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 8564 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8565 #endif 8566 8567 /* 8568 ** CAPI3REF: Low-level system error code 8569 ** 8570 ** ^Attempt to return the underlying operating system error code or error 8571 ** number that caused the most recent I/O error or failure to open a file. 8572 ** The return value is OS-dependent. For example, on unix systems, after 8573 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8574 ** called to get back the underlying "errno" that caused the problem, such 8575 ** as ENOSPC, EAUTH, EISDIR, and so forth. 8576 */ 8577 SQLITE_API int sqlite3_system_errno(sqlite3*); 8578 8579 /* 8580 ** CAPI3REF: Database Snapshot 8581 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 8582 ** EXPERIMENTAL 8583 ** 8584 ** An instance of the snapshot object records the state of a [WAL mode] 8585 ** database for some specific point in history. 8586 ** 8587 ** In [WAL mode], multiple [database connections] that are open on the 8588 ** same database file can each be reading a different historical version 8589 ** of the database file. When a [database connection] begins a read 8590 ** transaction, that connection sees an unchanging copy of the database 8591 ** as it existed for the point in time when the transaction first started. 8592 ** Subsequent changes to the database from other connections are not seen 8593 ** by the reader until a new read transaction is started. 8594 ** 8595 ** The sqlite3_snapshot object records state information about an historical 8596 ** version of the database file so that it is possible to later open a new read 8597 ** transaction that sees that historical version of the database rather than 8598 ** the most recent version. 8599 ** 8600 ** The constructor for this object is [sqlite3_snapshot_get()]. The 8601 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8602 ** to an historical snapshot (if possible). The destructor for 8603 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8604 */ 8605 typedef struct sqlite3_snapshot { 8606 unsigned char hidden[48]; 8607 } sqlite3_snapshot; 8608 8609 /* 8610 ** CAPI3REF: Record A Database Snapshot 8611 ** EXPERIMENTAL 8612 ** 8613 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8614 ** new [sqlite3_snapshot] object that records the current state of 8615 ** schema S in database connection D. ^On success, the 8616 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8617 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8618 ** If there is not already a read-transaction open on schema S when 8619 ** this function is called, one is opened automatically. 8620 ** 8621 ** The following must be true for this function to succeed. If any of 8622 ** the following statements are false when sqlite3_snapshot_get() is 8623 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 8624 ** in this case. 8625 ** 8626 ** <ul> 8627 ** <li> The database handle must be in [autocommit mode]. 8628 ** 8629 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 8630 ** 8631 ** <li> There must not be a write transaction open on schema S of database 8632 ** connection D. 8633 ** 8634 ** <li> One or more transactions must have been written to the current wal 8635 ** file since it was created on disk (by any connection). This means 8636 ** that a snapshot cannot be taken on a wal mode database with no wal 8637 ** file immediately after it is first opened. At least one transaction 8638 ** must be written to it first. 8639 ** </ul> 8640 ** 8641 ** This function may also return SQLITE_NOMEM. If it is called with the 8642 ** database handle in autocommit mode but fails for some other reason, 8643 ** whether or not a read transaction is opened on schema S is undefined. 8644 ** 8645 ** The [sqlite3_snapshot] object returned from a successful call to 8646 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8647 ** to avoid a memory leak. 8648 ** 8649 ** The [sqlite3_snapshot_get()] interface is only available when the 8650 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8651 */ 8652 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8653 sqlite3 *db, 8654 const char *zSchema, 8655 sqlite3_snapshot **ppSnapshot 8656 ); 8657 8658 /* 8659 ** CAPI3REF: Start a read transaction on an historical snapshot 8660 ** EXPERIMENTAL 8661 ** 8662 ** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8663 ** read transaction for schema S of 8664 ** [database connection] D such that the read transaction 8665 ** refers to historical [snapshot] P, rather than the most 8666 ** recent change to the database. 8667 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8668 ** or an appropriate [error code] if it fails. 8669 ** 8670 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8671 ** the first operation following the [BEGIN] that takes the schema S 8672 ** out of [autocommit mode]. 8673 ** ^In other words, schema S must not currently be in 8674 ** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8675 ** database connection D must be out of [autocommit mode]. 8676 ** ^A [snapshot] will fail to open if it has been overwritten by a 8677 ** [checkpoint]. 8678 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8679 ** database connection D does not know that the database file for 8680 ** schema S is in [WAL mode]. A database connection might not know 8681 ** that the database file is in [WAL mode] if there has been no prior 8682 ** I/O on that database connection, or if the database entered [WAL mode] 8683 ** after the most recent I/O on the database connection.)^ 8684 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 8685 ** database connection in order to make it ready to use snapshots.) 8686 ** 8687 ** The [sqlite3_snapshot_open()] interface is only available when the 8688 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8689 */ 8690 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8691 sqlite3 *db, 8692 const char *zSchema, 8693 sqlite3_snapshot *pSnapshot 8694 ); 8695 8696 /* 8697 ** CAPI3REF: Destroy a snapshot 8698 ** EXPERIMENTAL 8699 ** 8700 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8701 ** The application must eventually free every [sqlite3_snapshot] object 8702 ** using this routine to avoid a memory leak. 8703 ** 8704 ** The [sqlite3_snapshot_free()] interface is only available when the 8705 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8706 */ 8707 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8708 8709 /* 8710 ** CAPI3REF: Compare the ages of two snapshot handles. 8711 ** EXPERIMENTAL 8712 ** 8713 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8714 ** of two valid snapshot handles. 8715 ** 8716 ** If the two snapshot handles are not associated with the same database 8717 ** file, the result of the comparison is undefined. 8718 ** 8719 ** Additionally, the result of the comparison is only valid if both of the 8720 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8721 ** last time the wal file was deleted. The wal file is deleted when the 8722 ** database is changed back to rollback mode or when the number of database 8723 ** clients drops to zero. If either snapshot handle was obtained before the 8724 ** wal file was last deleted, the value returned by this function 8725 ** is undefined. 8726 ** 8727 ** Otherwise, this API returns a negative value if P1 refers to an older 8728 ** snapshot than P2, zero if the two handles refer to the same database 8729 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 8730 */ 8731 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8732 sqlite3_snapshot *p1, 8733 sqlite3_snapshot *p2 8734 ); 8735 8736 /* 8737 ** CAPI3REF: Recover snapshots from a wal file 8738 ** EXPERIMENTAL 8739 ** 8740 ** If all connections disconnect from a database file but do not perform 8741 ** a checkpoint, the existing wal file is opened along with the database 8742 ** file the next time the database is opened. At this point it is only 8743 ** possible to successfully call sqlite3_snapshot_open() to open the most 8744 ** recent snapshot of the database (the one at the head of the wal file), 8745 ** even though the wal file may contain other valid snapshots for which 8746 ** clients have sqlite3_snapshot handles. 8747 ** 8748 ** This function attempts to scan the wal file associated with database zDb 8749 ** of database handle db and make all valid snapshots available to 8750 ** sqlite3_snapshot_open(). It is an error if there is already a read 8751 ** transaction open on the database, or if the database is not a wal mode 8752 ** database. 8753 ** 8754 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 8755 */ 8756 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 8757 8758 /* 8759 ** CAPI3REF: Serialize a database 8760 ** 8761 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 8762 ** that is a serialization of the S database on [database connection] D. 8763 ** If P is not a NULL pointer, then the size of the database in bytes 8764 ** is written into *P. 8765 ** 8766 ** For an ordinary on-disk database file, the serialization is just a 8767 ** copy of the disk file. For an in-memory database or a "TEMP" database, 8768 ** the serialization is the same sequence of bytes which would be written 8769 ** to disk if that database where backed up to disk. 8770 ** 8771 ** The usual case is that sqlite3_serialize() copies the serialization of 8772 ** the database into memory obtained from [sqlite3_malloc64()] and returns 8773 ** a pointer to that memory. The caller is responsible for freeing the 8774 ** returned value to avoid a memory leak. However, if the F argument 8775 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 8776 ** are made, and the sqlite3_serialize() function will return a pointer 8777 ** to the contiguous memory representation of the database that SQLite 8778 ** is currently using for that database, or NULL if the no such contiguous 8779 ** memory representation of the database exists. A contiguous memory 8780 ** representation of the database will usually only exist if there has 8781 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 8782 ** values of D and S. 8783 ** The size of the database is written into *P even if the 8784 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contigious copy 8785 ** of the database exists. 8786 ** 8787 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 8788 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 8789 ** allocation error occurs. 8790 ** 8791 ** This interface is only available if SQLite is compiled with the 8792 ** [SQLITE_ENABLE_DESERIALIZE] option. 8793 */ 8794 SQLITE_API unsigned char *sqlite3_serialize( 8795 sqlite3 *db, /* The database connection */ 8796 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 8797 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 8798 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 8799 ); 8800 8801 /* 8802 ** CAPI3REF: Flags for sqlite3_serialize 8803 ** 8804 ** Zero or more of the following constants can be OR-ed together for 8805 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 8806 ** 8807 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 8808 ** a pointer to contiguous in-memory database that it is currently using, 8809 ** without making a copy of the database. If SQLite is not currently using 8810 ** a contiguous in-memory database, then this option causes 8811 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 8812 ** using a contiguous in-memory database if it has been initialized by a 8813 ** prior call to [sqlite3_deserialize()]. 8814 */ 8815 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 8816 8817 /* 8818 ** CAPI3REF: Deserialize a database 8819 ** 8820 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 8821 ** [database connection] D to disconnect from database S and then 8822 ** reopen S as an in-memory database based on the serialization contained 8823 ** in P. The serialized database P is N bytes in size. M is the size of 8824 ** the buffer P, which might be larger than N. If M is larger than N, and 8825 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 8826 ** permitted to add content to the in-memory database as long as the total 8827 ** size does not exceed M bytes. 8828 ** 8829 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 8830 ** invoke sqlite3_free() on the serialization buffer when the database 8831 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 8832 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 8833 ** if writes on the database cause it to grow larger than M bytes. 8834 ** 8835 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 8836 ** database is currently in a read transaction or is involved in a backup 8837 ** operation. 8838 ** 8839 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 8840 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 8841 ** [sqlite3_free()] is invoked on argument P prior to returning. 8842 ** 8843 ** This interface is only available if SQLite is compiled with the 8844 ** [SQLITE_ENABLE_DESERIALIZE] option. 8845 */ 8846 SQLITE_API int sqlite3_deserialize( 8847 sqlite3 *db, /* The database connection */ 8848 const char *zSchema, /* Which DB to reopen with the deserialization */ 8849 unsigned char *pData, /* The serialized database content */ 8850 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 8851 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 8852 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 8853 ); 8854 8855 /* 8856 ** CAPI3REF: Flags for sqlite3_deserialize() 8857 ** 8858 ** The following are allowed values for 6th argument (the F argument) to 8859 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 8860 ** 8861 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 8862 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 8863 ** and that SQLite should take ownership of this memory and automatically 8864 ** free it when it has finished using it. Without this flag, the caller 8865 ** is resposible for freeing any dynamically allocated memory. 8866 ** 8867 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 8868 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 8869 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 8870 ** Without this flag, the deserialized database cannot increase in size beyond 8871 ** the number of bytes specified by the M parameter. 8872 ** 8873 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 8874 ** should be treated as read-only. 8875 */ 8876 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 8877 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 8878 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 8879 8880 /* 8881 ** Undo the hack that converts floating point types to integer for 8882 ** builds on processors without floating point support. 8883 */ 8884 #ifdef SQLITE_OMIT_FLOATING_POINT 8885 # undef double 8886 #endif 8887 8888 #ifdef __cplusplus 8889 } /* End of the 'extern "C"' block */ 8890 #endif 8891 #endif /* SQLITE3_H */ 8892 8893 /******** Begin file sqlite3rtree.h *********/ 8894 /* 8895 ** 2010 August 30 8896 ** 8897 ** The author disclaims copyright to this source code. In place of 8898 ** a legal notice, here is a blessing: 8899 ** 8900 ** May you do good and not evil. 8901 ** May you find forgiveness for yourself and forgive others. 8902 ** May you share freely, never taking more than you give. 8903 ** 8904 ************************************************************************* 8905 */ 8906 8907 #ifndef _SQLITE3RTREE_H_ 8908 #define _SQLITE3RTREE_H_ 8909 8910 8911 #ifdef __cplusplus 8912 extern "C" { 8913 #endif 8914 8915 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8916 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8917 8918 /* The double-precision datatype used by RTree depends on the 8919 ** SQLITE_RTREE_INT_ONLY compile-time option. 8920 */ 8921 #ifdef SQLITE_RTREE_INT_ONLY 8922 typedef sqlite3_int64 sqlite3_rtree_dbl; 8923 #else 8924 typedef double sqlite3_rtree_dbl; 8925 #endif 8926 8927 /* 8928 ** Register a geometry callback named zGeom that can be used as part of an 8929 ** R-Tree geometry query as follows: 8930 ** 8931 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8932 */ 8933 SQLITE_API int sqlite3_rtree_geometry_callback( 8934 sqlite3 *db, 8935 const char *zGeom, 8936 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8937 void *pContext 8938 ); 8939 8940 8941 /* 8942 ** A pointer to a structure of the following type is passed as the first 8943 ** argument to callbacks registered using rtree_geometry_callback(). 8944 */ 8945 struct sqlite3_rtree_geometry { 8946 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8947 int nParam; /* Size of array aParam[] */ 8948 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8949 void *pUser; /* Callback implementation user data */ 8950 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8951 }; 8952 8953 /* 8954 ** Register a 2nd-generation geometry callback named zScore that can be 8955 ** used as part of an R-Tree geometry query as follows: 8956 ** 8957 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8958 */ 8959 SQLITE_API int sqlite3_rtree_query_callback( 8960 sqlite3 *db, 8961 const char *zQueryFunc, 8962 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8963 void *pContext, 8964 void (*xDestructor)(void*) 8965 ); 8966 8967 8968 /* 8969 ** A pointer to a structure of the following type is passed as the 8970 ** argument to scored geometry callback registered using 8971 ** sqlite3_rtree_query_callback(). 8972 ** 8973 ** Note that the first 5 fields of this structure are identical to 8974 ** sqlite3_rtree_geometry. This structure is a subclass of 8975 ** sqlite3_rtree_geometry. 8976 */ 8977 struct sqlite3_rtree_query_info { 8978 void *pContext; /* pContext from when function registered */ 8979 int nParam; /* Number of function parameters */ 8980 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8981 void *pUser; /* callback can use this, if desired */ 8982 void (*xDelUser)(void*); /* function to free pUser */ 8983 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8984 unsigned int *anQueue; /* Number of pending entries in the queue */ 8985 int nCoord; /* Number of coordinates */ 8986 int iLevel; /* Level of current node or entry */ 8987 int mxLevel; /* The largest iLevel value in the tree */ 8988 sqlite3_int64 iRowid; /* Rowid for current entry */ 8989 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8990 int eParentWithin; /* Visibility of parent node */ 8991 int eWithin; /* OUT: Visiblity */ 8992 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8993 /* The following fields are only available in 3.8.11 and later */ 8994 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8995 }; 8996 8997 /* 8998 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8999 */ 9000 #define NOT_WITHIN 0 /* Object completely outside of query region */ 9001 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9002 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 9003 9004 9005 #ifdef __cplusplus 9006 } /* end of the 'extern "C"' block */ 9007 #endif 9008 9009 #endif /* ifndef _SQLITE3RTREE_H_ */ 9010 9011 /******** End of sqlite3rtree.h *********/ 9012 /******** Begin file sqlite3session.h *********/ 9013 9014 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9015 #define __SQLITESESSION_H_ 1 9016 9017 /* 9018 ** Make sure we can call this stuff from C++. 9019 */ 9020 #ifdef __cplusplus 9021 extern "C" { 9022 #endif 9023 9024 9025 /* 9026 ** CAPI3REF: Session Object Handle 9027 ** 9028 ** An instance of this object is a [session] that can be used to 9029 ** record changes to a database. 9030 */ 9031 typedef struct sqlite3_session sqlite3_session; 9032 9033 /* 9034 ** CAPI3REF: Changeset Iterator Handle 9035 ** 9036 ** An instance of this object acts as a cursor for iterating 9037 ** over the elements of a [changeset] or [patchset]. 9038 */ 9039 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9040 9041 /* 9042 ** CAPI3REF: Create A New Session Object 9043 ** CONSTRUCTOR: sqlite3_session 9044 ** 9045 ** Create a new session object attached to database handle db. If successful, 9046 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 9047 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9048 ** error code (e.g. SQLITE_NOMEM) is returned. 9049 ** 9050 ** It is possible to create multiple session objects attached to a single 9051 ** database handle. 9052 ** 9053 ** Session objects created using this function should be deleted using the 9054 ** [sqlite3session_delete()] function before the database handle that they 9055 ** are attached to is itself closed. If the database handle is closed before 9056 ** the session object is deleted, then the results of calling any session 9057 ** module function, including [sqlite3session_delete()] on the session object 9058 ** are undefined. 9059 ** 9060 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9061 ** is not possible for an application to register a pre-update hook on a 9062 ** database handle that has one or more session objects attached. Nor is 9063 ** it possible to create a session object attached to a database handle for 9064 ** which a pre-update hook is already defined. The results of attempting 9065 ** either of these things are undefined. 9066 ** 9067 ** The session object will be used to create changesets for tables in 9068 ** database zDb, where zDb is either "main", or "temp", or the name of an 9069 ** attached database. It is not an error if database zDb is not attached 9070 ** to the database when the session object is created. 9071 */ 9072 SQLITE_API int sqlite3session_create( 9073 sqlite3 *db, /* Database handle */ 9074 const char *zDb, /* Name of db (e.g. "main") */ 9075 sqlite3_session **ppSession /* OUT: New session object */ 9076 ); 9077 9078 /* 9079 ** CAPI3REF: Delete A Session Object 9080 ** DESTRUCTOR: sqlite3_session 9081 ** 9082 ** Delete a session object previously allocated using 9083 ** [sqlite3session_create()]. Once a session object has been deleted, the 9084 ** results of attempting to use pSession with any other session module 9085 ** function are undefined. 9086 ** 9087 ** Session objects must be deleted before the database handle to which they 9088 ** are attached is closed. Refer to the documentation for 9089 ** [sqlite3session_create()] for details. 9090 */ 9091 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 9092 9093 9094 /* 9095 ** CAPI3REF: Enable Or Disable A Session Object 9096 ** METHOD: sqlite3_session 9097 ** 9098 ** Enable or disable the recording of changes by a session object. When 9099 ** enabled, a session object records changes made to the database. When 9100 ** disabled - it does not. A newly created session object is enabled. 9101 ** Refer to the documentation for [sqlite3session_changeset()] for further 9102 ** details regarding how enabling and disabling a session object affects 9103 ** the eventual changesets. 9104 ** 9105 ** Passing zero to this function disables the session. Passing a value 9106 ** greater than zero enables it. Passing a value less than zero is a 9107 ** no-op, and may be used to query the current state of the session. 9108 ** 9109 ** The return value indicates the final state of the session object: 0 if 9110 ** the session is disabled, or 1 if it is enabled. 9111 */ 9112 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 9113 9114 /* 9115 ** CAPI3REF: Set Or Clear the Indirect Change Flag 9116 ** METHOD: sqlite3_session 9117 ** 9118 ** Each change recorded by a session object is marked as either direct or 9119 ** indirect. A change is marked as indirect if either: 9120 ** 9121 ** <ul> 9122 ** <li> The session object "indirect" flag is set when the change is 9123 ** made, or 9124 ** <li> The change is made by an SQL trigger or foreign key action 9125 ** instead of directly as a result of a users SQL statement. 9126 ** </ul> 9127 ** 9128 ** If a single row is affected by more than one operation within a session, 9129 ** then the change is considered indirect if all operations meet the criteria 9130 ** for an indirect change above, or direct otherwise. 9131 ** 9132 ** This function is used to set, clear or query the session object indirect 9133 ** flag. If the second argument passed to this function is zero, then the 9134 ** indirect flag is cleared. If it is greater than zero, the indirect flag 9135 ** is set. Passing a value less than zero does not modify the current value 9136 ** of the indirect flag, and may be used to query the current state of the 9137 ** indirect flag for the specified session object. 9138 ** 9139 ** The return value indicates the final state of the indirect flag: 0 if 9140 ** it is clear, or 1 if it is set. 9141 */ 9142 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 9143 9144 /* 9145 ** CAPI3REF: Attach A Table To A Session Object 9146 ** METHOD: sqlite3_session 9147 ** 9148 ** If argument zTab is not NULL, then it is the name of a table to attach 9149 ** to the session object passed as the first argument. All subsequent changes 9150 ** made to the table while the session object is enabled will be recorded. See 9151 ** documentation for [sqlite3session_changeset()] for further details. 9152 ** 9153 ** Or, if argument zTab is NULL, then changes are recorded for all tables 9154 ** in the database. If additional tables are added to the database (by 9155 ** executing "CREATE TABLE" statements) after this call is made, changes for 9156 ** the new tables are also recorded. 9157 ** 9158 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 9159 ** defined as part of their CREATE TABLE statement. It does not matter if the 9160 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 9161 ** KEY may consist of a single column, or may be a composite key. 9162 ** 9163 ** It is not an error if the named table does not exist in the database. Nor 9164 ** is it an error if the named table does not have a PRIMARY KEY. However, 9165 ** no changes will be recorded in either of these scenarios. 9166 ** 9167 ** Changes are not recorded for individual rows that have NULL values stored 9168 ** in one or more of their PRIMARY KEY columns. 9169 ** 9170 ** SQLITE_OK is returned if the call completes without error. Or, if an error 9171 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 9172 ** 9173 ** <h3>Special sqlite_stat1 Handling</h3> 9174 ** 9175 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 9176 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 9177 ** <pre> 9178 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 9179 ** </pre> 9180 ** 9181 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 9182 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 9183 ** are recorded for rows for which (idx IS NULL) is true. However, for such 9184 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 9185 ** patchset instead of a NULL value. This allows such changesets to be 9186 ** manipulated by legacy implementations of sqlite3changeset_invert(), 9187 ** concat() and similar. 9188 ** 9189 ** The sqlite3changeset_apply() function automatically converts the 9190 ** zero-length blob back to a NULL value when updating the sqlite_stat1 9191 ** table. However, if the application calls sqlite3changeset_new(), 9192 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 9193 ** iterator directly (including on a changeset iterator passed to a 9194 ** conflict-handler callback) then the X'' value is returned. The application 9195 ** must translate X'' to NULL itself if required. 9196 ** 9197 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 9198 ** changes made to the sqlite_stat1 table. Legacy versions of the 9199 ** sqlite3changeset_apply() function silently ignore any modifications to the 9200 ** sqlite_stat1 table that are part of a changeset or patchset. 9201 */ 9202 SQLITE_API int sqlite3session_attach( 9203 sqlite3_session *pSession, /* Session object */ 9204 const char *zTab /* Table name */ 9205 ); 9206 9207 /* 9208 ** CAPI3REF: Set a table filter on a Session Object. 9209 ** METHOD: sqlite3_session 9210 ** 9211 ** The second argument (xFilter) is the "filter callback". For changes to rows 9212 ** in tables that are not attached to the Session object, the filter is called 9213 ** to determine whether changes to the table's rows should be tracked or not. 9214 ** If xFilter returns 0, changes is not tracked. Note that once a table is 9215 ** attached, xFilter will not be called again. 9216 */ 9217 SQLITE_API void sqlite3session_table_filter( 9218 sqlite3_session *pSession, /* Session object */ 9219 int(*xFilter)( 9220 void *pCtx, /* Copy of third arg to _filter_table() */ 9221 const char *zTab /* Table name */ 9222 ), 9223 void *pCtx /* First argument passed to xFilter */ 9224 ); 9225 9226 /* 9227 ** CAPI3REF: Generate A Changeset From A Session Object 9228 ** METHOD: sqlite3_session 9229 ** 9230 ** Obtain a changeset containing changes to the tables attached to the 9231 ** session object passed as the first argument. If successful, 9232 ** set *ppChangeset to point to a buffer containing the changeset 9233 ** and *pnChangeset to the size of the changeset in bytes before returning 9234 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 9235 ** zero and return an SQLite error code. 9236 ** 9237 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 9238 ** each representing a change to a single row of an attached table. An INSERT 9239 ** change contains the values of each field of a new database row. A DELETE 9240 ** contains the original values of each field of a deleted database row. An 9241 ** UPDATE change contains the original values of each field of an updated 9242 ** database row along with the updated values for each updated non-primary-key 9243 ** column. It is not possible for an UPDATE change to represent a change that 9244 ** modifies the values of primary key columns. If such a change is made, it 9245 ** is represented in a changeset as a DELETE followed by an INSERT. 9246 ** 9247 ** Changes are not recorded for rows that have NULL values stored in one or 9248 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 9249 ** no corresponding change is present in the changesets returned by this 9250 ** function. If an existing row with one or more NULL values stored in 9251 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 9252 ** only an INSERT is appears in the changeset. Similarly, if an existing row 9253 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 9254 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 9255 ** DELETE change only. 9256 ** 9257 ** The contents of a changeset may be traversed using an iterator created 9258 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 9259 ** a database with a compatible schema using the [sqlite3changeset_apply()] 9260 ** API. 9261 ** 9262 ** Within a changeset generated by this function, all changes related to a 9263 ** single table are grouped together. In other words, when iterating through 9264 ** a changeset or when applying a changeset to a database, all changes related 9265 ** to a single table are processed before moving on to the next table. Tables 9266 ** are sorted in the same order in which they were attached (or auto-attached) 9267 ** to the sqlite3_session object. The order in which the changes related to 9268 ** a single table are stored is undefined. 9269 ** 9270 ** Following a successful call to this function, it is the responsibility of 9271 ** the caller to eventually free the buffer that *ppChangeset points to using 9272 ** [sqlite3_free()]. 9273 ** 9274 ** <h3>Changeset Generation</h3> 9275 ** 9276 ** Once a table has been attached to a session object, the session object 9277 ** records the primary key values of all new rows inserted into the table. 9278 ** It also records the original primary key and other column values of any 9279 ** deleted or updated rows. For each unique primary key value, data is only 9280 ** recorded once - the first time a row with said primary key is inserted, 9281 ** updated or deleted in the lifetime of the session. 9282 ** 9283 ** There is one exception to the previous paragraph: when a row is inserted, 9284 ** updated or deleted, if one or more of its primary key columns contain a 9285 ** NULL value, no record of the change is made. 9286 ** 9287 ** The session object therefore accumulates two types of records - those 9288 ** that consist of primary key values only (created when the user inserts 9289 ** a new record) and those that consist of the primary key values and the 9290 ** original values of other table columns (created when the users deletes 9291 ** or updates a record). 9292 ** 9293 ** When this function is called, the requested changeset is created using 9294 ** both the accumulated records and the current contents of the database 9295 ** file. Specifically: 9296 ** 9297 ** <ul> 9298 ** <li> For each record generated by an insert, the database is queried 9299 ** for a row with a matching primary key. If one is found, an INSERT 9300 ** change is added to the changeset. If no such row is found, no change 9301 ** is added to the changeset. 9302 ** 9303 ** <li> For each record generated by an update or delete, the database is 9304 ** queried for a row with a matching primary key. If such a row is 9305 ** found and one or more of the non-primary key fields have been 9306 ** modified from their original values, an UPDATE change is added to 9307 ** the changeset. Or, if no such row is found in the table, a DELETE 9308 ** change is added to the changeset. If there is a row with a matching 9309 ** primary key in the database, but all fields contain their original 9310 ** values, no change is added to the changeset. 9311 ** </ul> 9312 ** 9313 ** This means, amongst other things, that if a row is inserted and then later 9314 ** deleted while a session object is active, neither the insert nor the delete 9315 ** will be present in the changeset. Or if a row is deleted and then later a 9316 ** row with the same primary key values inserted while a session object is 9317 ** active, the resulting changeset will contain an UPDATE change instead of 9318 ** a DELETE and an INSERT. 9319 ** 9320 ** When a session object is disabled (see the [sqlite3session_enable()] API), 9321 ** it does not accumulate records when rows are inserted, updated or deleted. 9322 ** This may appear to have some counter-intuitive effects if a single row 9323 ** is written to more than once during a session. For example, if a row 9324 ** is inserted while a session object is enabled, then later deleted while 9325 ** the same session object is disabled, no INSERT record will appear in the 9326 ** changeset, even though the delete took place while the session was disabled. 9327 ** Or, if one field of a row is updated while a session is disabled, and 9328 ** another field of the same row is updated while the session is enabled, the 9329 ** resulting changeset will contain an UPDATE change that updates both fields. 9330 */ 9331 SQLITE_API int sqlite3session_changeset( 9332 sqlite3_session *pSession, /* Session object */ 9333 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 9334 void **ppChangeset /* OUT: Buffer containing changeset */ 9335 ); 9336 9337 /* 9338 ** CAPI3REF: Load The Difference Between Tables Into A Session 9339 ** METHOD: sqlite3_session 9340 ** 9341 ** If it is not already attached to the session object passed as the first 9342 ** argument, this function attaches table zTbl in the same manner as the 9343 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 9344 ** does not have a primary key, this function is a no-op (but does not return 9345 ** an error). 9346 ** 9347 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 9348 ** attached to the same database handle as the session object that contains 9349 ** a table compatible with the table attached to the session by this function. 9350 ** A table is considered compatible if it: 9351 ** 9352 ** <ul> 9353 ** <li> Has the same name, 9354 ** <li> Has the same set of columns declared in the same order, and 9355 ** <li> Has the same PRIMARY KEY definition. 9356 ** </ul> 9357 ** 9358 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 9359 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 9360 ** but no changes are added to the session object. As with other session 9361 ** APIs, tables without PRIMARY KEYs are simply ignored. 9362 ** 9363 ** This function adds a set of changes to the session object that could be 9364 ** used to update the table in database zFrom (call this the "from-table") 9365 ** so that its content is the same as the table attached to the session 9366 ** object (call this the "to-table"). Specifically: 9367 ** 9368 ** <ul> 9369 ** <li> For each row (primary key) that exists in the to-table but not in 9370 ** the from-table, an INSERT record is added to the session object. 9371 ** 9372 ** <li> For each row (primary key) that exists in the to-table but not in 9373 ** the from-table, a DELETE record is added to the session object. 9374 ** 9375 ** <li> For each row (primary key) that exists in both tables, but features 9376 ** different non-PK values in each, an UPDATE record is added to the 9377 ** session. 9378 ** </ul> 9379 ** 9380 ** To clarify, if this function is called and then a changeset constructed 9381 ** using [sqlite3session_changeset()], then after applying that changeset to 9382 ** database zFrom the contents of the two compatible tables would be 9383 ** identical. 9384 ** 9385 ** It an error if database zFrom does not exist or does not contain the 9386 ** required compatible table. 9387 ** 9388 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 9389 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 9390 ** may be set to point to a buffer containing an English language error 9391 ** message. It is the responsibility of the caller to free this buffer using 9392 ** sqlite3_free(). 9393 */ 9394 SQLITE_API int sqlite3session_diff( 9395 sqlite3_session *pSession, 9396 const char *zFromDb, 9397 const char *zTbl, 9398 char **pzErrMsg 9399 ); 9400 9401 9402 /* 9403 ** CAPI3REF: Generate A Patchset From A Session Object 9404 ** METHOD: sqlite3_session 9405 ** 9406 ** The differences between a patchset and a changeset are that: 9407 ** 9408 ** <ul> 9409 ** <li> DELETE records consist of the primary key fields only. The 9410 ** original values of other fields are omitted. 9411 ** <li> The original values of any modified fields are omitted from 9412 ** UPDATE records. 9413 ** </ul> 9414 ** 9415 ** A patchset blob may be used with up to date versions of all 9416 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 9417 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 9418 ** attempting to use a patchset blob with old versions of the 9419 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 9420 ** 9421 ** Because the non-primary key "old.*" fields are omitted, no 9422 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 9423 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 9424 ** in the same way as for changesets. 9425 ** 9426 ** Changes within a patchset are ordered in the same way as for changesets 9427 ** generated by the sqlite3session_changeset() function (i.e. all changes for 9428 ** a single table are grouped together, tables appear in the order in which 9429 ** they were attached to the session object). 9430 */ 9431 SQLITE_API int sqlite3session_patchset( 9432 sqlite3_session *pSession, /* Session object */ 9433 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 9434 void **ppPatchset /* OUT: Buffer containing patchset */ 9435 ); 9436 9437 /* 9438 ** CAPI3REF: Test if a changeset has recorded any changes. 9439 ** 9440 ** Return non-zero if no changes to attached tables have been recorded by 9441 ** the session object passed as the first argument. Otherwise, if one or 9442 ** more changes have been recorded, return zero. 9443 ** 9444 ** Even if this function returns zero, it is possible that calling 9445 ** [sqlite3session_changeset()] on the session handle may still return a 9446 ** changeset that contains no changes. This can happen when a row in 9447 ** an attached table is modified and then later on the original values 9448 ** are restored. However, if this function returns non-zero, then it is 9449 ** guaranteed that a call to sqlite3session_changeset() will return a 9450 ** changeset containing zero changes. 9451 */ 9452 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 9453 9454 /* 9455 ** CAPI3REF: Create An Iterator To Traverse A Changeset 9456 ** CONSTRUCTOR: sqlite3_changeset_iter 9457 ** 9458 ** Create an iterator used to iterate through the contents of a changeset. 9459 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 9460 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 9461 ** SQLite error code is returned. 9462 ** 9463 ** The following functions can be used to advance and query a changeset 9464 ** iterator created by this function: 9465 ** 9466 ** <ul> 9467 ** <li> [sqlite3changeset_next()] 9468 ** <li> [sqlite3changeset_op()] 9469 ** <li> [sqlite3changeset_new()] 9470 ** <li> [sqlite3changeset_old()] 9471 ** </ul> 9472 ** 9473 ** It is the responsibility of the caller to eventually destroy the iterator 9474 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 9475 ** changeset (pChangeset) must remain valid until after the iterator is 9476 ** destroyed. 9477 ** 9478 ** Assuming the changeset blob was created by one of the 9479 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9480 ** [sqlite3changeset_invert()] functions, all changes within the changeset 9481 ** that apply to a single table are grouped together. This means that when 9482 ** an application iterates through a changeset using an iterator created by 9483 ** this function, all changes that relate to a single table are visited 9484 ** consecutively. There is no chance that the iterator will visit a change 9485 ** the applies to table X, then one for table Y, and then later on visit 9486 ** another change for table X. 9487 */ 9488 SQLITE_API int sqlite3changeset_start( 9489 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9490 int nChangeset, /* Size of changeset blob in bytes */ 9491 void *pChangeset /* Pointer to blob containing changeset */ 9492 ); 9493 9494 9495 /* 9496 ** CAPI3REF: Advance A Changeset Iterator 9497 ** METHOD: sqlite3_changeset_iter 9498 ** 9499 ** This function may only be used with iterators created by function 9500 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 9501 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 9502 ** is returned and the call has no effect. 9503 ** 9504 ** Immediately after an iterator is created by sqlite3changeset_start(), it 9505 ** does not point to any change in the changeset. Assuming the changeset 9506 ** is not empty, the first call to this function advances the iterator to 9507 ** point to the first change in the changeset. Each subsequent call advances 9508 ** the iterator to point to the next change in the changeset (if any). If 9509 ** no error occurs and the iterator points to a valid change after a call 9510 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 9511 ** Otherwise, if all changes in the changeset have already been visited, 9512 ** SQLITE_DONE is returned. 9513 ** 9514 ** If an error occurs, an SQLite error code is returned. Possible error 9515 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 9516 ** SQLITE_NOMEM. 9517 */ 9518 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 9519 9520 /* 9521 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 9522 ** METHOD: sqlite3_changeset_iter 9523 ** 9524 ** The pIter argument passed to this function may either be an iterator 9525 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9526 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9527 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 9528 ** is not the case, this function returns [SQLITE_MISUSE]. 9529 ** 9530 ** If argument pzTab is not NULL, then *pzTab is set to point to a 9531 ** nul-terminated utf-8 encoded string containing the name of the table 9532 ** affected by the current change. The buffer remains valid until either 9533 ** sqlite3changeset_next() is called on the iterator or until the 9534 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 9535 ** set to the number of columns in the table affected by the change. If 9536 ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 9537 ** is an indirect change, or false (0) otherwise. See the documentation for 9538 ** [sqlite3session_indirect()] for a description of direct and indirect 9539 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 9540 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 9541 ** type of change that the iterator currently points to. 9542 ** 9543 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 9544 ** SQLite error code is returned. The values of the output variables may not 9545 ** be trusted in this case. 9546 */ 9547 SQLITE_API int sqlite3changeset_op( 9548 sqlite3_changeset_iter *pIter, /* Iterator object */ 9549 const char **pzTab, /* OUT: Pointer to table name */ 9550 int *pnCol, /* OUT: Number of columns in table */ 9551 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 9552 int *pbIndirect /* OUT: True for an 'indirect' change */ 9553 ); 9554 9555 /* 9556 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 9557 ** METHOD: sqlite3_changeset_iter 9558 ** 9559 ** For each modified table, a changeset includes the following: 9560 ** 9561 ** <ul> 9562 ** <li> The number of columns in the table, and 9563 ** <li> Which of those columns make up the tables PRIMARY KEY. 9564 ** </ul> 9565 ** 9566 ** This function is used to find which columns comprise the PRIMARY KEY of 9567 ** the table modified by the change that iterator pIter currently points to. 9568 ** If successful, *pabPK is set to point to an array of nCol entries, where 9569 ** nCol is the number of columns in the table. Elements of *pabPK are set to 9570 ** 0x01 if the corresponding column is part of the tables primary key, or 9571 ** 0x00 if it is not. 9572 ** 9573 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 9574 ** in the table. 9575 ** 9576 ** If this function is called when the iterator does not point to a valid 9577 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9578 ** SQLITE_OK is returned and the output variables populated as described 9579 ** above. 9580 */ 9581 SQLITE_API int sqlite3changeset_pk( 9582 sqlite3_changeset_iter *pIter, /* Iterator object */ 9583 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9584 int *pnCol /* OUT: Number of entries in output array */ 9585 ); 9586 9587 /* 9588 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9589 ** METHOD: sqlite3_changeset_iter 9590 ** 9591 ** The pIter argument passed to this function may either be an iterator 9592 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9593 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9594 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9595 ** Furthermore, it may only be called if the type of change that the iterator 9596 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9597 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9598 ** 9599 ** Argument iVal must be greater than or equal to 0, and less than the number 9600 ** of columns in the table affected by the current change. Otherwise, 9601 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9602 ** 9603 ** If successful, this function sets *ppValue to point to a protected 9604 ** sqlite3_value object containing the iVal'th value from the vector of 9605 ** original row values stored as part of the UPDATE or DELETE change and 9606 ** returns SQLITE_OK. The name of the function comes from the fact that this 9607 ** is similar to the "old.*" columns available to update or delete triggers. 9608 ** 9609 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9610 ** is returned and *ppValue is set to NULL. 9611 */ 9612 SQLITE_API int sqlite3changeset_old( 9613 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9614 int iVal, /* Column number */ 9615 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 9616 ); 9617 9618 /* 9619 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 9620 ** METHOD: sqlite3_changeset_iter 9621 ** 9622 ** The pIter argument passed to this function may either be an iterator 9623 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9624 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9625 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9626 ** Furthermore, it may only be called if the type of change that the iterator 9627 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 9628 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9629 ** 9630 ** Argument iVal must be greater than or equal to 0, and less than the number 9631 ** of columns in the table affected by the current change. Otherwise, 9632 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9633 ** 9634 ** If successful, this function sets *ppValue to point to a protected 9635 ** sqlite3_value object containing the iVal'th value from the vector of 9636 ** new row values stored as part of the UPDATE or INSERT change and 9637 ** returns SQLITE_OK. If the change is an UPDATE and does not include 9638 ** a new value for the requested column, *ppValue is set to NULL and 9639 ** SQLITE_OK returned. The name of the function comes from the fact that 9640 ** this is similar to the "new.*" columns available to update or delete 9641 ** triggers. 9642 ** 9643 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9644 ** is returned and *ppValue is set to NULL. 9645 */ 9646 SQLITE_API int sqlite3changeset_new( 9647 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9648 int iVal, /* Column number */ 9649 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 9650 ); 9651 9652 /* 9653 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 9654 ** METHOD: sqlite3_changeset_iter 9655 ** 9656 ** This function should only be used with iterator objects passed to a 9657 ** conflict-handler callback by [sqlite3changeset_apply()] with either 9658 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 9659 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 9660 ** is set to NULL. 9661 ** 9662 ** Argument iVal must be greater than or equal to 0, and less than the number 9663 ** of columns in the table affected by the current change. Otherwise, 9664 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9665 ** 9666 ** If successful, this function sets *ppValue to point to a protected 9667 ** sqlite3_value object containing the iVal'th value from the 9668 ** "conflicting row" associated with the current conflict-handler callback 9669 ** and returns SQLITE_OK. 9670 ** 9671 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9672 ** is returned and *ppValue is set to NULL. 9673 */ 9674 SQLITE_API int sqlite3changeset_conflict( 9675 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9676 int iVal, /* Column number */ 9677 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 9678 ); 9679 9680 /* 9681 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 9682 ** METHOD: sqlite3_changeset_iter 9683 ** 9684 ** This function may only be called with an iterator passed to an 9685 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 9686 ** it sets the output variable to the total number of known foreign key 9687 ** violations in the destination database and returns SQLITE_OK. 9688 ** 9689 ** In all other cases this function returns SQLITE_MISUSE. 9690 */ 9691 SQLITE_API int sqlite3changeset_fk_conflicts( 9692 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9693 int *pnOut /* OUT: Number of FK violations */ 9694 ); 9695 9696 9697 /* 9698 ** CAPI3REF: Finalize A Changeset Iterator 9699 ** METHOD: sqlite3_changeset_iter 9700 ** 9701 ** This function is used to finalize an iterator allocated with 9702 ** [sqlite3changeset_start()]. 9703 ** 9704 ** This function should only be called on iterators created using the 9705 ** [sqlite3changeset_start()] function. If an application calls this 9706 ** function with an iterator passed to a conflict-handler by 9707 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 9708 ** call has no effect. 9709 ** 9710 ** If an error was encountered within a call to an sqlite3changeset_xxx() 9711 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 9712 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 9713 ** to that error is returned by this function. Otherwise, SQLITE_OK is 9714 ** returned. This is to allow the following pattern (pseudo-code): 9715 ** 9716 ** <pre> 9717 ** sqlite3changeset_start(); 9718 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 9719 ** // Do something with change. 9720 ** } 9721 ** rc = sqlite3changeset_finalize(); 9722 ** if( rc!=SQLITE_OK ){ 9723 ** // An error has occurred 9724 ** } 9725 ** </pre> 9726 */ 9727 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 9728 9729 /* 9730 ** CAPI3REF: Invert A Changeset 9731 ** 9732 ** This function is used to "invert" a changeset object. Applying an inverted 9733 ** changeset to a database reverses the effects of applying the uninverted 9734 ** changeset. Specifically: 9735 ** 9736 ** <ul> 9737 ** <li> Each DELETE change is changed to an INSERT, and 9738 ** <li> Each INSERT change is changed to a DELETE, and 9739 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 9740 ** </ul> 9741 ** 9742 ** This function does not change the order in which changes appear within 9743 ** the changeset. It merely reverses the sense of each individual change. 9744 ** 9745 ** If successful, a pointer to a buffer containing the inverted changeset 9746 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 9747 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 9748 ** zeroed and an SQLite error code returned. 9749 ** 9750 ** It is the responsibility of the caller to eventually call sqlite3_free() 9751 ** on the *ppOut pointer to free the buffer allocation following a successful 9752 ** call to this function. 9753 ** 9754 ** WARNING/TODO: This function currently assumes that the input is a valid 9755 ** changeset. If it is not, the results are undefined. 9756 */ 9757 SQLITE_API int sqlite3changeset_invert( 9758 int nIn, const void *pIn, /* Input changeset */ 9759 int *pnOut, void **ppOut /* OUT: Inverse of input */ 9760 ); 9761 9762 /* 9763 ** CAPI3REF: Concatenate Two Changeset Objects 9764 ** 9765 ** This function is used to concatenate two changesets, A and B, into a 9766 ** single changeset. The result is a changeset equivalent to applying 9767 ** changeset A followed by changeset B. 9768 ** 9769 ** This function combines the two input changesets using an 9770 ** sqlite3_changegroup object. Calling it produces similar results as the 9771 ** following code fragment: 9772 ** 9773 ** <pre> 9774 ** sqlite3_changegroup *pGrp; 9775 ** rc = sqlite3_changegroup_new(&pGrp); 9776 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 9777 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 9778 ** if( rc==SQLITE_OK ){ 9779 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 9780 ** }else{ 9781 ** *ppOut = 0; 9782 ** *pnOut = 0; 9783 ** } 9784 ** </pre> 9785 ** 9786 ** Refer to the sqlite3_changegroup documentation below for details. 9787 */ 9788 SQLITE_API int sqlite3changeset_concat( 9789 int nA, /* Number of bytes in buffer pA */ 9790 void *pA, /* Pointer to buffer containing changeset A */ 9791 int nB, /* Number of bytes in buffer pB */ 9792 void *pB, /* Pointer to buffer containing changeset B */ 9793 int *pnOut, /* OUT: Number of bytes in output changeset */ 9794 void **ppOut /* OUT: Buffer containing output changeset */ 9795 ); 9796 9797 9798 /* 9799 ** CAPI3REF: Changegroup Handle 9800 ** 9801 ** A changegroup is an object used to combine two or more 9802 ** [changesets] or [patchsets] 9803 */ 9804 typedef struct sqlite3_changegroup sqlite3_changegroup; 9805 9806 /* 9807 ** CAPI3REF: Create A New Changegroup Object 9808 ** CONSTRUCTOR: sqlite3_changegroup 9809 ** 9810 ** An sqlite3_changegroup object is used to combine two or more changesets 9811 ** (or patchsets) into a single changeset (or patchset). A single changegroup 9812 ** object may combine changesets or patchsets, but not both. The output is 9813 ** always in the same format as the input. 9814 ** 9815 ** If successful, this function returns SQLITE_OK and populates (*pp) with 9816 ** a pointer to a new sqlite3_changegroup object before returning. The caller 9817 ** should eventually free the returned object using a call to 9818 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 9819 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 9820 ** 9821 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 9822 ** 9823 ** <ul> 9824 ** <li> It is created using a call to sqlite3changegroup_new(). 9825 ** 9826 ** <li> Zero or more changesets (or patchsets) are added to the object 9827 ** by calling sqlite3changegroup_add(). 9828 ** 9829 ** <li> The result of combining all input changesets together is obtained 9830 ** by the application via a call to sqlite3changegroup_output(). 9831 ** 9832 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 9833 ** </ul> 9834 ** 9835 ** Any number of calls to add() and output() may be made between the calls to 9836 ** new() and delete(), and in any order. 9837 ** 9838 ** As well as the regular sqlite3changegroup_add() and 9839 ** sqlite3changegroup_output() functions, also available are the streaming 9840 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 9841 */ 9842 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 9843 9844 /* 9845 ** CAPI3REF: Add A Changeset To A Changegroup 9846 ** METHOD: sqlite3_changegroup 9847 ** 9848 ** Add all changes within the changeset (or patchset) in buffer pData (size 9849 ** nData bytes) to the changegroup. 9850 ** 9851 ** If the buffer contains a patchset, then all prior calls to this function 9852 ** on the same changegroup object must also have specified patchsets. Or, if 9853 ** the buffer contains a changeset, so must have the earlier calls to this 9854 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 9855 ** to the changegroup. 9856 ** 9857 ** Rows within the changeset and changegroup are identified by the values in 9858 ** their PRIMARY KEY columns. A change in the changeset is considered to 9859 ** apply to the same row as a change already present in the changegroup if 9860 ** the two rows have the same primary key. 9861 ** 9862 ** Changes to rows that do not already appear in the changegroup are 9863 ** simply copied into it. Or, if both the new changeset and the changegroup 9864 ** contain changes that apply to a single row, the final contents of the 9865 ** changegroup depends on the type of each change, as follows: 9866 ** 9867 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9868 ** <tr><th style="white-space:pre">Existing Change </th> 9869 ** <th style="white-space:pre">New Change </th> 9870 ** <th>Output Change 9871 ** <tr><td>INSERT <td>INSERT <td> 9872 ** The new change is ignored. This case does not occur if the new 9873 ** changeset was recorded immediately after the changesets already 9874 ** added to the changegroup. 9875 ** <tr><td>INSERT <td>UPDATE <td> 9876 ** The INSERT change remains in the changegroup. The values in the 9877 ** INSERT change are modified as if the row was inserted by the 9878 ** existing change and then updated according to the new change. 9879 ** <tr><td>INSERT <td>DELETE <td> 9880 ** The existing INSERT is removed from the changegroup. The DELETE is 9881 ** not added. 9882 ** <tr><td>UPDATE <td>INSERT <td> 9883 ** The new change is ignored. This case does not occur if the new 9884 ** changeset was recorded immediately after the changesets already 9885 ** added to the changegroup. 9886 ** <tr><td>UPDATE <td>UPDATE <td> 9887 ** The existing UPDATE remains within the changegroup. It is amended 9888 ** so that the accompanying values are as if the row was updated once 9889 ** by the existing change and then again by the new change. 9890 ** <tr><td>UPDATE <td>DELETE <td> 9891 ** The existing UPDATE is replaced by the new DELETE within the 9892 ** changegroup. 9893 ** <tr><td>DELETE <td>INSERT <td> 9894 ** If one or more of the column values in the row inserted by the 9895 ** new change differ from those in the row deleted by the existing 9896 ** change, the existing DELETE is replaced by an UPDATE within the 9897 ** changegroup. Otherwise, if the inserted row is exactly the same 9898 ** as the deleted row, the existing DELETE is simply discarded. 9899 ** <tr><td>DELETE <td>UPDATE <td> 9900 ** The new change is ignored. This case does not occur if the new 9901 ** changeset was recorded immediately after the changesets already 9902 ** added to the changegroup. 9903 ** <tr><td>DELETE <td>DELETE <td> 9904 ** The new change is ignored. This case does not occur if the new 9905 ** changeset was recorded immediately after the changesets already 9906 ** added to the changegroup. 9907 ** </table> 9908 ** 9909 ** If the new changeset contains changes to a table that is already present 9910 ** in the changegroup, then the number of columns and the position of the 9911 ** primary key columns for the table must be consistent. If this is not the 9912 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 9913 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 9914 ** returned. Or, if an out-of-memory condition occurs during processing, this 9915 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 9916 ** final contents of the changegroup is undefined. 9917 ** 9918 ** If no error occurs, SQLITE_OK is returned. 9919 */ 9920 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 9921 9922 /* 9923 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 9924 ** METHOD: sqlite3_changegroup 9925 ** 9926 ** Obtain a buffer containing a changeset (or patchset) representing the 9927 ** current contents of the changegroup. If the inputs to the changegroup 9928 ** were themselves changesets, the output is a changeset. Or, if the 9929 ** inputs were patchsets, the output is also a patchset. 9930 ** 9931 ** As with the output of the sqlite3session_changeset() and 9932 ** sqlite3session_patchset() functions, all changes related to a single 9933 ** table are grouped together in the output of this function. Tables appear 9934 ** in the same order as for the very first changeset added to the changegroup. 9935 ** If the second or subsequent changesets added to the changegroup contain 9936 ** changes for tables that do not appear in the first changeset, they are 9937 ** appended onto the end of the output changeset, again in the order in 9938 ** which they are first encountered. 9939 ** 9940 ** If an error occurs, an SQLite error code is returned and the output 9941 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 9942 ** is returned and the output variables are set to the size of and a 9943 ** pointer to the output buffer, respectively. In this case it is the 9944 ** responsibility of the caller to eventually free the buffer using a 9945 ** call to sqlite3_free(). 9946 */ 9947 SQLITE_API int sqlite3changegroup_output( 9948 sqlite3_changegroup*, 9949 int *pnData, /* OUT: Size of output buffer in bytes */ 9950 void **ppData /* OUT: Pointer to output buffer */ 9951 ); 9952 9953 /* 9954 ** CAPI3REF: Delete A Changegroup Object 9955 ** DESTRUCTOR: sqlite3_changegroup 9956 */ 9957 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 9958 9959 /* 9960 ** CAPI3REF: Apply A Changeset To A Database 9961 ** 9962 ** Apply a changeset or patchset to a database. These functions attempt to 9963 ** update the "main" database attached to handle db with the changes found in 9964 ** the changeset passed via the second and third arguments. 9965 ** 9966 ** The fourth argument (xFilter) passed to these functions is the "filter 9967 ** callback". If it is not NULL, then for each table affected by at least one 9968 ** change in the changeset, the filter callback is invoked with 9969 ** the table name as the second argument, and a copy of the context pointer 9970 ** passed as the sixth argument as the first. If the "filter callback" 9971 ** returns zero, then no attempt is made to apply any changes to the table. 9972 ** Otherwise, if the return value is non-zero or the xFilter argument to 9973 ** is NULL, all changes related to the table are attempted. 9974 ** 9975 ** For each table that is not excluded by the filter callback, this function 9976 ** tests that the target database contains a compatible table. A table is 9977 ** considered compatible if all of the following are true: 9978 ** 9979 ** <ul> 9980 ** <li> The table has the same name as the name recorded in the 9981 ** changeset, and 9982 ** <li> The table has at least as many columns as recorded in the 9983 ** changeset, and 9984 ** <li> The table has primary key columns in the same position as 9985 ** recorded in the changeset. 9986 ** </ul> 9987 ** 9988 ** If there is no compatible table, it is not an error, but none of the 9989 ** changes associated with the table are applied. A warning message is issued 9990 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 9991 ** one such warning is issued for each table in the changeset. 9992 ** 9993 ** For each change for which there is a compatible table, an attempt is made 9994 ** to modify the table contents according to the UPDATE, INSERT or DELETE 9995 ** change. If a change cannot be applied cleanly, the conflict handler 9996 ** function passed as the fifth argument to sqlite3changeset_apply() may be 9997 ** invoked. A description of exactly when the conflict handler is invoked for 9998 ** each type of change is below. 9999 ** 10000 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10001 ** of passing anything other than a valid function pointer as the xConflict 10002 ** argument are undefined. 10003 ** 10004 ** Each time the conflict handler function is invoked, it must return one 10005 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10006 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10007 ** if the second argument passed to the conflict handler is either 10008 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10009 ** returns an illegal value, any changes already made are rolled back and 10010 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10011 ** actions are taken by sqlite3changeset_apply() depending on the value 10012 ** returned by each invocation of the conflict-handler function. Refer to 10013 ** the documentation for the three 10014 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 10015 ** 10016 ** <dl> 10017 ** <dt>DELETE Changes<dd> 10018 ** For each DELETE change, the function checks if the target database 10019 ** contains a row with the same primary key value (or values) as the 10020 ** original row values stored in the changeset. If it does, and the values 10021 ** stored in all non-primary key columns also match the values stored in 10022 ** the changeset the row is deleted from the target database. 10023 ** 10024 ** If a row with matching primary key values is found, but one or more of 10025 ** the non-primary key fields contains a value different from the original 10026 ** row value stored in the changeset, the conflict-handler function is 10027 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10028 ** database table has more columns than are recorded in the changeset, 10029 ** only the values of those non-primary key fields are compared against 10030 ** the current database contents - any trailing database table columns 10031 ** are ignored. 10032 ** 10033 ** If no row with matching primary key values is found in the database, 10034 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10035 ** passed as the second argument. 10036 ** 10037 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10038 ** (which can only happen if a foreign key constraint is violated), the 10039 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10040 ** passed as the second argument. This includes the case where the DELETE 10041 ** operation is attempted because an earlier call to the conflict handler 10042 ** function returned [SQLITE_CHANGESET_REPLACE]. 10043 ** 10044 ** <dt>INSERT Changes<dd> 10045 ** For each INSERT change, an attempt is made to insert the new row into 10046 ** the database. If the changeset row contains fewer fields than the 10047 ** database table, the trailing fields are populated with their default 10048 ** values. 10049 ** 10050 ** If the attempt to insert the row fails because the database already 10051 ** contains a row with the same primary key values, the conflict handler 10052 ** function is invoked with the second argument set to 10053 ** [SQLITE_CHANGESET_CONFLICT]. 10054 ** 10055 ** If the attempt to insert the row fails because of some other constraint 10056 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 10057 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 10058 ** This includes the case where the INSERT operation is re-attempted because 10059 ** an earlier call to the conflict handler function returned 10060 ** [SQLITE_CHANGESET_REPLACE]. 10061 ** 10062 ** <dt>UPDATE Changes<dd> 10063 ** For each UPDATE change, the function checks if the target database 10064 ** contains a row with the same primary key value (or values) as the 10065 ** original row values stored in the changeset. If it does, and the values 10066 ** stored in all modified non-primary key columns also match the values 10067 ** stored in the changeset the row is updated within the target database. 10068 ** 10069 ** If a row with matching primary key values is found, but one or more of 10070 ** the modified non-primary key fields contains a value different from an 10071 ** original row value stored in the changeset, the conflict-handler function 10072 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 10073 ** UPDATE changes only contain values for non-primary key fields that are 10074 ** to be modified, only those fields need to match the original values to 10075 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 10076 ** 10077 ** If no row with matching primary key values is found in the database, 10078 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10079 ** passed as the second argument. 10080 ** 10081 ** If the UPDATE operation is attempted, but SQLite returns 10082 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 10083 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 10084 ** This includes the case where the UPDATE operation is attempted after 10085 ** an earlier call to the conflict handler function returned 10086 ** [SQLITE_CHANGESET_REPLACE]. 10087 ** </dl> 10088 ** 10089 ** It is safe to execute SQL statements, including those that write to the 10090 ** table that the callback related to, from within the xConflict callback. 10091 ** This can be used to further customize the applications conflict 10092 ** resolution strategy. 10093 ** 10094 ** All changes made by these functions are enclosed in a savepoint transaction. 10095 ** If any other error (aside from a constraint failure when attempting to 10096 ** write to the target database) occurs, then the savepoint transaction is 10097 ** rolled back, restoring the target database to its original state, and an 10098 ** SQLite error code returned. 10099 ** 10100 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 10101 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 10102 ** may set (*ppRebase) to point to a "rebase" that may be used with the 10103 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 10104 ** is set to the size of the buffer in bytes. It is the responsibility of the 10105 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 10106 ** is only allocated and populated if one or more conflicts were encountered 10107 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 10108 ** APIs for further details. 10109 ** 10110 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 10111 ** may be modified by passing a combination of 10112 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 10113 ** 10114 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 10115 ** and therefore subject to change. 10116 */ 10117 SQLITE_API int sqlite3changeset_apply( 10118 sqlite3 *db, /* Apply change to "main" db of this handle */ 10119 int nChangeset, /* Size of changeset in bytes */ 10120 void *pChangeset, /* Changeset blob */ 10121 int(*xFilter)( 10122 void *pCtx, /* Copy of sixth arg to _apply() */ 10123 const char *zTab /* Table name */ 10124 ), 10125 int(*xConflict)( 10126 void *pCtx, /* Copy of sixth arg to _apply() */ 10127 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10128 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10129 ), 10130 void *pCtx /* First argument passed to xConflict */ 10131 ); 10132 SQLITE_API int sqlite3changeset_apply_v2( 10133 sqlite3 *db, /* Apply change to "main" db of this handle */ 10134 int nChangeset, /* Size of changeset in bytes */ 10135 void *pChangeset, /* Changeset blob */ 10136 int(*xFilter)( 10137 void *pCtx, /* Copy of sixth arg to _apply() */ 10138 const char *zTab /* Table name */ 10139 ), 10140 int(*xConflict)( 10141 void *pCtx, /* Copy of sixth arg to _apply() */ 10142 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10143 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10144 ), 10145 void *pCtx, /* First argument passed to xConflict */ 10146 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 10147 int flags /* Combination of SESSION_APPLY_* flags */ 10148 ); 10149 10150 /* 10151 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 10152 ** 10153 ** The following flags may passed via the 9th parameter to 10154 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 10155 ** 10156 ** <dl> 10157 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 10158 ** Usually, the sessions module encloses all operations performed by 10159 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 10160 ** SAVEPOINT is committed if the changeset or patchset is successfully 10161 ** applied, or rolled back if an error occurs. Specifying this flag 10162 ** causes the sessions module to omit this savepoint. In this case, if the 10163 ** caller has an open transaction or savepoint when apply_v2() is called, 10164 ** it may revert the partially applied changeset by rolling it back. 10165 */ 10166 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 10167 10168 /* 10169 ** CAPI3REF: Constants Passed To The Conflict Handler 10170 ** 10171 ** Values that may be passed as the second argument to a conflict-handler. 10172 ** 10173 ** <dl> 10174 ** <dt>SQLITE_CHANGESET_DATA<dd> 10175 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 10176 ** when processing a DELETE or UPDATE change if a row with the required 10177 ** PRIMARY KEY fields is present in the database, but one or more other 10178 ** (non primary-key) fields modified by the update do not contain the 10179 ** expected "before" values. 10180 ** 10181 ** The conflicting row, in this case, is the database row with the matching 10182 ** primary key. 10183 ** 10184 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 10185 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 10186 ** argument when processing a DELETE or UPDATE change if a row with the 10187 ** required PRIMARY KEY fields is not present in the database. 10188 ** 10189 ** There is no conflicting row in this case. The results of invoking the 10190 ** sqlite3changeset_conflict() API are undefined. 10191 ** 10192 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 10193 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 10194 ** handler while processing an INSERT change if the operation would result 10195 ** in duplicate primary key values. 10196 ** 10197 ** The conflicting row in this case is the database row with the matching 10198 ** primary key. 10199 ** 10200 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 10201 ** If foreign key handling is enabled, and applying a changeset leaves the 10202 ** database in a state containing foreign key violations, the conflict 10203 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 10204 ** exactly once before the changeset is committed. If the conflict handler 10205 ** returns CHANGESET_OMIT, the changes, including those that caused the 10206 ** foreign key constraint violation, are committed. Or, if it returns 10207 ** CHANGESET_ABORT, the changeset is rolled back. 10208 ** 10209 ** No current or conflicting row information is provided. The only function 10210 ** it is possible to call on the supplied sqlite3_changeset_iter handle 10211 ** is sqlite3changeset_fk_conflicts(). 10212 ** 10213 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 10214 ** If any other constraint violation occurs while applying a change (i.e. 10215 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 10216 ** invoked with CHANGESET_CONSTRAINT as the second argument. 10217 ** 10218 ** There is no conflicting row in this case. The results of invoking the 10219 ** sqlite3changeset_conflict() API are undefined. 10220 ** 10221 ** </dl> 10222 */ 10223 #define SQLITE_CHANGESET_DATA 1 10224 #define SQLITE_CHANGESET_NOTFOUND 2 10225 #define SQLITE_CHANGESET_CONFLICT 3 10226 #define SQLITE_CHANGESET_CONSTRAINT 4 10227 #define SQLITE_CHANGESET_FOREIGN_KEY 5 10228 10229 /* 10230 ** CAPI3REF: Constants Returned By The Conflict Handler 10231 ** 10232 ** A conflict handler callback must return one of the following three values. 10233 ** 10234 ** <dl> 10235 ** <dt>SQLITE_CHANGESET_OMIT<dd> 10236 ** If a conflict handler returns this value no special action is taken. The 10237 ** change that caused the conflict is not applied. The session module 10238 ** continues to the next change in the changeset. 10239 ** 10240 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 10241 ** This value may only be returned if the second argument to the conflict 10242 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 10243 ** is not the case, any changes applied so far are rolled back and the 10244 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 10245 ** 10246 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 10247 ** handler, then the conflicting row is either updated or deleted, depending 10248 ** on the type of change. 10249 ** 10250 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 10251 ** handler, then the conflicting row is removed from the database and a 10252 ** second attempt to apply the change is made. If this second attempt fails, 10253 ** the original row is restored to the database before continuing. 10254 ** 10255 ** <dt>SQLITE_CHANGESET_ABORT<dd> 10256 ** If this value is returned, any changes applied so far are rolled back 10257 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 10258 ** </dl> 10259 */ 10260 #define SQLITE_CHANGESET_OMIT 0 10261 #define SQLITE_CHANGESET_REPLACE 1 10262 #define SQLITE_CHANGESET_ABORT 2 10263 10264 /* 10265 ** CAPI3REF: Rebasing changesets 10266 ** EXPERIMENTAL 10267 ** 10268 ** Suppose there is a site hosting a database in state S0. And that 10269 ** modifications are made that move that database to state S1 and a 10270 ** changeset recorded (the "local" changeset). Then, a changeset based 10271 ** on S0 is received from another site (the "remote" changeset) and 10272 ** applied to the database. The database is then in state 10273 ** (S1+"remote"), where the exact state depends on any conflict 10274 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 10275 ** Rebasing a changeset is to update it to take those conflict 10276 ** resolution decisions into account, so that the same conflicts 10277 ** do not have to be resolved elsewhere in the network. 10278 ** 10279 ** For example, if both the local and remote changesets contain an 10280 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 10281 ** 10282 ** local: INSERT INTO t1 VALUES(1, 'v1'); 10283 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 10284 ** 10285 ** and the conflict resolution is REPLACE, then the INSERT change is 10286 ** removed from the local changeset (it was overridden). Or, if the 10287 ** conflict resolution was "OMIT", then the local changeset is modified 10288 ** to instead contain: 10289 ** 10290 ** UPDATE t1 SET b = 'v2' WHERE a=1; 10291 ** 10292 ** Changes within the local changeset are rebased as follows: 10293 ** 10294 ** <dl> 10295 ** <dt>Local INSERT<dd> 10296 ** This may only conflict with a remote INSERT. If the conflict 10297 ** resolution was OMIT, then add an UPDATE change to the rebased 10298 ** changeset. Or, if the conflict resolution was REPLACE, add 10299 ** nothing to the rebased changeset. 10300 ** 10301 ** <dt>Local DELETE<dd> 10302 ** This may conflict with a remote UPDATE or DELETE. In both cases the 10303 ** only possible resolution is OMIT. If the remote operation was a 10304 ** DELETE, then add no change to the rebased changeset. If the remote 10305 ** operation was an UPDATE, then the old.* fields of change are updated 10306 ** to reflect the new.* values in the UPDATE. 10307 ** 10308 ** <dt>Local UPDATE<dd> 10309 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 10310 ** with a DELETE, and the conflict resolution was OMIT, then the update 10311 ** is changed into an INSERT. Any undefined values in the new.* record 10312 ** from the update change are filled in using the old.* values from 10313 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 10314 ** the UPDATE change is simply omitted from the rebased changeset. 10315 ** 10316 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 10317 ** the old.* values are rebased using the new.* values in the remote 10318 ** change. Or, if the resolution is REPLACE, then the change is copied 10319 ** into the rebased changeset with updates to columns also updated by 10320 ** the conflicting remote UPDATE removed. If this means no columns would 10321 ** be updated, the change is omitted. 10322 ** </dl> 10323 ** 10324 ** A local change may be rebased against multiple remote changes 10325 ** simultaneously. If a single key is modified by multiple remote 10326 ** changesets, they are combined as follows before the local changeset 10327 ** is rebased: 10328 ** 10329 ** <ul> 10330 ** <li> If there has been one or more REPLACE resolutions on a 10331 ** key, it is rebased according to a REPLACE. 10332 ** 10333 ** <li> If there have been no REPLACE resolutions on a key, then 10334 ** the local changeset is rebased according to the most recent 10335 ** of the OMIT resolutions. 10336 ** </ul> 10337 ** 10338 ** Note that conflict resolutions from multiple remote changesets are 10339 ** combined on a per-field basis, not per-row. This means that in the 10340 ** case of multiple remote UPDATE operations, some fields of a single 10341 ** local change may be rebased for REPLACE while others are rebased for 10342 ** OMIT. 10343 ** 10344 ** In order to rebase a local changeset, the remote changeset must first 10345 ** be applied to the local database using sqlite3changeset_apply_v2() and 10346 ** the buffer of rebase information captured. Then: 10347 ** 10348 ** <ol> 10349 ** <li> An sqlite3_rebaser object is created by calling 10350 ** sqlite3rebaser_create(). 10351 ** <li> The new object is configured with the rebase buffer obtained from 10352 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 10353 ** If the local changeset is to be rebased against multiple remote 10354 ** changesets, then sqlite3rebaser_configure() should be called 10355 ** multiple times, in the same order that the multiple 10356 ** sqlite3changeset_apply_v2() calls were made. 10357 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 10358 ** <li> The sqlite3_rebaser object is deleted by calling 10359 ** sqlite3rebaser_delete(). 10360 ** </ol> 10361 */ 10362 typedef struct sqlite3_rebaser sqlite3_rebaser; 10363 10364 /* 10365 ** CAPI3REF: Create a changeset rebaser object. 10366 ** EXPERIMENTAL 10367 ** 10368 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 10369 ** point to the new object and return SQLITE_OK. Otherwise, if an error 10370 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 10371 ** to NULL. 10372 */ 10373 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 10374 10375 /* 10376 ** CAPI3REF: Configure a changeset rebaser object. 10377 ** EXPERIMENTAL 10378 ** 10379 ** Configure the changeset rebaser object to rebase changesets according 10380 ** to the conflict resolutions described by buffer pRebase (size nRebase 10381 ** bytes), which must have been obtained from a previous call to 10382 ** sqlite3changeset_apply_v2(). 10383 */ 10384 SQLITE_API int sqlite3rebaser_configure( 10385 sqlite3_rebaser*, 10386 int nRebase, const void *pRebase 10387 ); 10388 10389 /* 10390 ** CAPI3REF: Rebase a changeset 10391 ** EXPERIMENTAL 10392 ** 10393 ** Argument pIn must point to a buffer containing a changeset nIn bytes 10394 ** in size. This function allocates and populates a buffer with a copy 10395 ** of the changeset rebased rebased according to the configuration of the 10396 ** rebaser object passed as the first argument. If successful, (*ppOut) 10397 ** is set to point to the new buffer containing the rebased changset and 10398 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 10399 ** responsibility of the caller to eventually free the new buffer using 10400 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 10401 ** are set to zero and an SQLite error code returned. 10402 */ 10403 SQLITE_API int sqlite3rebaser_rebase( 10404 sqlite3_rebaser*, 10405 int nIn, const void *pIn, 10406 int *pnOut, void **ppOut 10407 ); 10408 10409 /* 10410 ** CAPI3REF: Delete a changeset rebaser object. 10411 ** EXPERIMENTAL 10412 ** 10413 ** Delete the changeset rebaser object and all associated resources. There 10414 ** should be one call to this function for each successful invocation 10415 ** of sqlite3rebaser_create(). 10416 */ 10417 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 10418 10419 /* 10420 ** CAPI3REF: Streaming Versions of API functions. 10421 ** 10422 ** The six streaming API xxx_strm() functions serve similar purposes to the 10423 ** corresponding non-streaming API functions: 10424 ** 10425 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10426 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 10427 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 10428 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 10429 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 10430 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 10431 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 10432 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 10433 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 10434 ** </table> 10435 ** 10436 ** Non-streaming functions that accept changesets (or patchsets) as input 10437 ** require that the entire changeset be stored in a single buffer in memory. 10438 ** Similarly, those that return a changeset or patchset do so by returning 10439 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 10440 ** Normally this is convenient. However, if an application running in a 10441 ** low-memory environment is required to handle very large changesets, the 10442 ** large contiguous memory allocations required can become onerous. 10443 ** 10444 ** In order to avoid this problem, instead of a single large buffer, input 10445 ** is passed to a streaming API functions by way of a callback function that 10446 ** the sessions module invokes to incrementally request input data as it is 10447 ** required. In all cases, a pair of API function parameters such as 10448 ** 10449 ** <pre> 10450 ** int nChangeset, 10451 ** void *pChangeset, 10452 ** </pre> 10453 ** 10454 ** Is replaced by: 10455 ** 10456 ** <pre> 10457 ** int (*xInput)(void *pIn, void *pData, int *pnData), 10458 ** void *pIn, 10459 ** </pre> 10460 ** 10461 ** Each time the xInput callback is invoked by the sessions module, the first 10462 ** argument passed is a copy of the supplied pIn context pointer. The second 10463 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 10464 ** error occurs the xInput method should copy up to (*pnData) bytes of data 10465 ** into the buffer and set (*pnData) to the actual number of bytes copied 10466 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 10467 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 10468 ** error code should be returned. In all cases, if an xInput callback returns 10469 ** an error, all processing is abandoned and the streaming API function 10470 ** returns a copy of the error code to the caller. 10471 ** 10472 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 10473 ** invoked by the sessions module at any point during the lifetime of the 10474 ** iterator. If such an xInput callback returns an error, the iterator enters 10475 ** an error state, whereby all subsequent calls to iterator functions 10476 ** immediately fail with the same error code as returned by xInput. 10477 ** 10478 ** Similarly, streaming API functions that return changesets (or patchsets) 10479 ** return them in chunks by way of a callback function instead of via a 10480 ** pointer to a single large buffer. In this case, a pair of parameters such 10481 ** as: 10482 ** 10483 ** <pre> 10484 ** int *pnChangeset, 10485 ** void **ppChangeset, 10486 ** </pre> 10487 ** 10488 ** Is replaced by: 10489 ** 10490 ** <pre> 10491 ** int (*xOutput)(void *pOut, const void *pData, int nData), 10492 ** void *pOut 10493 ** </pre> 10494 ** 10495 ** The xOutput callback is invoked zero or more times to return data to 10496 ** the application. The first parameter passed to each call is a copy of the 10497 ** pOut pointer supplied by the application. The second parameter, pData, 10498 ** points to a buffer nData bytes in size containing the chunk of output 10499 ** data being returned. If the xOutput callback successfully processes the 10500 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 10501 ** it should return some other SQLite error code. In this case processing 10502 ** is immediately abandoned and the streaming API function returns a copy 10503 ** of the xOutput error code to the application. 10504 ** 10505 ** The sessions module never invokes an xOutput callback with the third 10506 ** parameter set to a value less than or equal to zero. Other than this, 10507 ** no guarantees are made as to the size of the chunks of data returned. 10508 */ 10509 SQLITE_API int sqlite3changeset_apply_strm( 10510 sqlite3 *db, /* Apply change to "main" db of this handle */ 10511 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 10512 void *pIn, /* First arg for xInput */ 10513 int(*xFilter)( 10514 void *pCtx, /* Copy of sixth arg to _apply() */ 10515 const char *zTab /* Table name */ 10516 ), 10517 int(*xConflict)( 10518 void *pCtx, /* Copy of sixth arg to _apply() */ 10519 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10520 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10521 ), 10522 void *pCtx /* First argument passed to xConflict */ 10523 ); 10524 SQLITE_API int sqlite3changeset_apply_v2_strm( 10525 sqlite3 *db, /* Apply change to "main" db of this handle */ 10526 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 10527 void *pIn, /* First arg for xInput */ 10528 int(*xFilter)( 10529 void *pCtx, /* Copy of sixth arg to _apply() */ 10530 const char *zTab /* Table name */ 10531 ), 10532 int(*xConflict)( 10533 void *pCtx, /* Copy of sixth arg to _apply() */ 10534 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10535 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10536 ), 10537 void *pCtx, /* First argument passed to xConflict */ 10538 void **ppRebase, int *pnRebase, 10539 int flags 10540 ); 10541 SQLITE_API int sqlite3changeset_concat_strm( 10542 int (*xInputA)(void *pIn, void *pData, int *pnData), 10543 void *pInA, 10544 int (*xInputB)(void *pIn, void *pData, int *pnData), 10545 void *pInB, 10546 int (*xOutput)(void *pOut, const void *pData, int nData), 10547 void *pOut 10548 ); 10549 SQLITE_API int sqlite3changeset_invert_strm( 10550 int (*xInput)(void *pIn, void *pData, int *pnData), 10551 void *pIn, 10552 int (*xOutput)(void *pOut, const void *pData, int nData), 10553 void *pOut 10554 ); 10555 SQLITE_API int sqlite3changeset_start_strm( 10556 sqlite3_changeset_iter **pp, 10557 int (*xInput)(void *pIn, void *pData, int *pnData), 10558 void *pIn 10559 ); 10560 SQLITE_API int sqlite3session_changeset_strm( 10561 sqlite3_session *pSession, 10562 int (*xOutput)(void *pOut, const void *pData, int nData), 10563 void *pOut 10564 ); 10565 SQLITE_API int sqlite3session_patchset_strm( 10566 sqlite3_session *pSession, 10567 int (*xOutput)(void *pOut, const void *pData, int nData), 10568 void *pOut 10569 ); 10570 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 10571 int (*xInput)(void *pIn, void *pData, int *pnData), 10572 void *pIn 10573 ); 10574 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 10575 int (*xOutput)(void *pOut, const void *pData, int nData), 10576 void *pOut 10577 ); 10578 SQLITE_API int sqlite3rebaser_rebase_strm( 10579 sqlite3_rebaser *pRebaser, 10580 int (*xInput)(void *pIn, void *pData, int *pnData), 10581 void *pIn, 10582 int (*xOutput)(void *pOut, const void *pData, int nData), 10583 void *pOut 10584 ); 10585 10586 10587 /* 10588 ** Make sure we can call this stuff from C++. 10589 */ 10590 #ifdef __cplusplus 10591 } 10592 #endif 10593 10594 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 10595 10596 /******** End of sqlite3session.h *********/ 10597 /******** Begin file fts5.h *********/ 10598 /* 10599 ** 2014 May 31 10600 ** 10601 ** The author disclaims copyright to this source code. In place of 10602 ** a legal notice, here is a blessing: 10603 ** 10604 ** May you do good and not evil. 10605 ** May you find forgiveness for yourself and forgive others. 10606 ** May you share freely, never taking more than you give. 10607 ** 10608 ****************************************************************************** 10609 ** 10610 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 10611 ** FTS5 may be extended with: 10612 ** 10613 ** * custom tokenizers, and 10614 ** * custom auxiliary functions. 10615 */ 10616 10617 10618 #ifndef _FTS5_H 10619 #define _FTS5_H 10620 10621 10622 #ifdef __cplusplus 10623 extern "C" { 10624 #endif 10625 10626 /************************************************************************* 10627 ** CUSTOM AUXILIARY FUNCTIONS 10628 ** 10629 ** Virtual table implementations may overload SQL functions by implementing 10630 ** the sqlite3_module.xFindFunction() method. 10631 */ 10632 10633 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 10634 typedef struct Fts5Context Fts5Context; 10635 typedef struct Fts5PhraseIter Fts5PhraseIter; 10636 10637 typedef void (*fts5_extension_function)( 10638 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 10639 Fts5Context *pFts, /* First arg to pass to pApi functions */ 10640 sqlite3_context *pCtx, /* Context for returning result/error */ 10641 int nVal, /* Number of values in apVal[] array */ 10642 sqlite3_value **apVal /* Array of trailing arguments */ 10643 ); 10644 10645 struct Fts5PhraseIter { 10646 const unsigned char *a; 10647 const unsigned char *b; 10648 }; 10649 10650 /* 10651 ** EXTENSION API FUNCTIONS 10652 ** 10653 ** xUserData(pFts): 10654 ** Return a copy of the context pointer the extension function was 10655 ** registered with. 10656 ** 10657 ** xColumnTotalSize(pFts, iCol, pnToken): 10658 ** If parameter iCol is less than zero, set output variable *pnToken 10659 ** to the total number of tokens in the FTS5 table. Or, if iCol is 10660 ** non-negative but less than the number of columns in the table, return 10661 ** the total number of tokens in column iCol, considering all rows in 10662 ** the FTS5 table. 10663 ** 10664 ** If parameter iCol is greater than or equal to the number of columns 10665 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 10666 ** an OOM condition or IO error), an appropriate SQLite error code is 10667 ** returned. 10668 ** 10669 ** xColumnCount(pFts): 10670 ** Return the number of columns in the table. 10671 ** 10672 ** xColumnSize(pFts, iCol, pnToken): 10673 ** If parameter iCol is less than zero, set output variable *pnToken 10674 ** to the total number of tokens in the current row. Or, if iCol is 10675 ** non-negative but less than the number of columns in the table, set 10676 ** *pnToken to the number of tokens in column iCol of the current row. 10677 ** 10678 ** If parameter iCol is greater than or equal to the number of columns 10679 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 10680 ** an OOM condition or IO error), an appropriate SQLite error code is 10681 ** returned. 10682 ** 10683 ** This function may be quite inefficient if used with an FTS5 table 10684 ** created with the "columnsize=0" option. 10685 ** 10686 ** xColumnText: 10687 ** This function attempts to retrieve the text of column iCol of the 10688 ** current document. If successful, (*pz) is set to point to a buffer 10689 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 10690 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 10691 ** if an error occurs, an SQLite error code is returned and the final values 10692 ** of (*pz) and (*pn) are undefined. 10693 ** 10694 ** xPhraseCount: 10695 ** Returns the number of phrases in the current query expression. 10696 ** 10697 ** xPhraseSize: 10698 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 10699 ** are numbered starting from zero. 10700 ** 10701 ** xInstCount: 10702 ** Set *pnInst to the total number of occurrences of all phrases within 10703 ** the query within the current row. Return SQLITE_OK if successful, or 10704 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 10705 ** 10706 ** This API can be quite slow if used with an FTS5 table created with the 10707 ** "detail=none" or "detail=column" option. If the FTS5 table is created 10708 ** with either "detail=none" or "detail=column" and "content=" option 10709 ** (i.e. if it is a contentless table), then this API always returns 0. 10710 ** 10711 ** xInst: 10712 ** Query for the details of phrase match iIdx within the current row. 10713 ** Phrase matches are numbered starting from zero, so the iIdx argument 10714 ** should be greater than or equal to zero and smaller than the value 10715 ** output by xInstCount(). 10716 ** 10717 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 10718 ** to the column in which it occurs and *piOff the token offset of the 10719 ** first token of the phrase. The exception is if the table was created 10720 ** with the offsets=0 option specified. In this case *piOff is always 10721 ** set to -1. 10722 ** 10723 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 10724 ** if an error occurs. 10725 ** 10726 ** This API can be quite slow if used with an FTS5 table created with the 10727 ** "detail=none" or "detail=column" option. 10728 ** 10729 ** xRowid: 10730 ** Returns the rowid of the current row. 10731 ** 10732 ** xTokenize: 10733 ** Tokenize text using the tokenizer belonging to the FTS5 table. 10734 ** 10735 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 10736 ** This API function is used to query the FTS table for phrase iPhrase 10737 ** of the current query. Specifically, a query equivalent to: 10738 ** 10739 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 10740 ** 10741 ** with $p set to a phrase equivalent to the phrase iPhrase of the 10742 ** current query is executed. Any column filter that applies to 10743 ** phrase iPhrase of the current query is included in $p. For each 10744 ** row visited, the callback function passed as the fourth argument 10745 ** is invoked. The context and API objects passed to the callback 10746 ** function may be used to access the properties of each matched row. 10747 ** Invoking Api.xUserData() returns a copy of the pointer passed as 10748 ** the third argument to pUserData. 10749 ** 10750 ** If the callback function returns any value other than SQLITE_OK, the 10751 ** query is abandoned and the xQueryPhrase function returns immediately. 10752 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 10753 ** Otherwise, the error code is propagated upwards. 10754 ** 10755 ** If the query runs to completion without incident, SQLITE_OK is returned. 10756 ** Or, if some error occurs before the query completes or is aborted by 10757 ** the callback, an SQLite error code is returned. 10758 ** 10759 ** 10760 ** xSetAuxdata(pFts5, pAux, xDelete) 10761 ** 10762 ** Save the pointer passed as the second argument as the extension functions 10763 ** "auxiliary data". The pointer may then be retrieved by the current or any 10764 ** future invocation of the same fts5 extension function made as part of 10765 ** of the same MATCH query using the xGetAuxdata() API. 10766 ** 10767 ** Each extension function is allocated a single auxiliary data slot for 10768 ** each FTS query (MATCH expression). If the extension function is invoked 10769 ** more than once for a single FTS query, then all invocations share a 10770 ** single auxiliary data context. 10771 ** 10772 ** If there is already an auxiliary data pointer when this function is 10773 ** invoked, then it is replaced by the new pointer. If an xDelete callback 10774 ** was specified along with the original pointer, it is invoked at this 10775 ** point. 10776 ** 10777 ** The xDelete callback, if one is specified, is also invoked on the 10778 ** auxiliary data pointer after the FTS5 query has finished. 10779 ** 10780 ** If an error (e.g. an OOM condition) occurs within this function, an 10781 ** the auxiliary data is set to NULL and an error code returned. If the 10782 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 10783 ** pointer before returning. 10784 ** 10785 ** 10786 ** xGetAuxdata(pFts5, bClear) 10787 ** 10788 ** Returns the current auxiliary data pointer for the fts5 extension 10789 ** function. See the xSetAuxdata() method for details. 10790 ** 10791 ** If the bClear argument is non-zero, then the auxiliary data is cleared 10792 ** (set to NULL) before this function returns. In this case the xDelete, 10793 ** if any, is not invoked. 10794 ** 10795 ** 10796 ** xRowCount(pFts5, pnRow) 10797 ** 10798 ** This function is used to retrieve the total number of rows in the table. 10799 ** In other words, the same value that would be returned by: 10800 ** 10801 ** SELECT count(*) FROM ftstable; 10802 ** 10803 ** xPhraseFirst() 10804 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 10805 ** method, to iterate through all instances of a single query phrase within 10806 ** the current row. This is the same information as is accessible via the 10807 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 10808 ** to use, this API may be faster under some circumstances. To iterate 10809 ** through instances of phrase iPhrase, use the following code: 10810 ** 10811 ** Fts5PhraseIter iter; 10812 ** int iCol, iOff; 10813 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 10814 ** iCol>=0; 10815 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 10816 ** ){ 10817 ** // An instance of phrase iPhrase at offset iOff of column iCol 10818 ** } 10819 ** 10820 ** The Fts5PhraseIter structure is defined above. Applications should not 10821 ** modify this structure directly - it should only be used as shown above 10822 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 10823 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 10824 ** 10825 ** This API can be quite slow if used with an FTS5 table created with the 10826 ** "detail=none" or "detail=column" option. If the FTS5 table is created 10827 ** with either "detail=none" or "detail=column" and "content=" option 10828 ** (i.e. if it is a contentless table), then this API always iterates 10829 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 10830 ** 10831 ** xPhraseNext() 10832 ** See xPhraseFirst above. 10833 ** 10834 ** xPhraseFirstColumn() 10835 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 10836 ** and xPhraseNext() APIs described above. The difference is that instead 10837 ** of iterating through all instances of a phrase in the current row, these 10838 ** APIs are used to iterate through the set of columns in the current row 10839 ** that contain one or more instances of a specified phrase. For example: 10840 ** 10841 ** Fts5PhraseIter iter; 10842 ** int iCol; 10843 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 10844 ** iCol>=0; 10845 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 10846 ** ){ 10847 ** // Column iCol contains at least one instance of phrase iPhrase 10848 ** } 10849 ** 10850 ** This API can be quite slow if used with an FTS5 table created with the 10851 ** "detail=none" option. If the FTS5 table is created with either 10852 ** "detail=none" "content=" option (i.e. if it is a contentless table), 10853 ** then this API always iterates through an empty set (all calls to 10854 ** xPhraseFirstColumn() set iCol to -1). 10855 ** 10856 ** The information accessed using this API and its companion 10857 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 10858 ** (or xInst/xInstCount). The chief advantage of this API is that it is 10859 ** significantly more efficient than those alternatives when used with 10860 ** "detail=column" tables. 10861 ** 10862 ** xPhraseNextColumn() 10863 ** See xPhraseFirstColumn above. 10864 */ 10865 struct Fts5ExtensionApi { 10866 int iVersion; /* Currently always set to 3 */ 10867 10868 void *(*xUserData)(Fts5Context*); 10869 10870 int (*xColumnCount)(Fts5Context*); 10871 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 10872 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 10873 10874 int (*xTokenize)(Fts5Context*, 10875 const char *pText, int nText, /* Text to tokenize */ 10876 void *pCtx, /* Context passed to xToken() */ 10877 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 10878 ); 10879 10880 int (*xPhraseCount)(Fts5Context*); 10881 int (*xPhraseSize)(Fts5Context*, int iPhrase); 10882 10883 int (*xInstCount)(Fts5Context*, int *pnInst); 10884 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 10885 10886 sqlite3_int64 (*xRowid)(Fts5Context*); 10887 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 10888 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 10889 10890 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 10891 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 10892 ); 10893 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 10894 void *(*xGetAuxdata)(Fts5Context*, int bClear); 10895 10896 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 10897 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 10898 10899 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 10900 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 10901 }; 10902 10903 /* 10904 ** CUSTOM AUXILIARY FUNCTIONS 10905 *************************************************************************/ 10906 10907 /************************************************************************* 10908 ** CUSTOM TOKENIZERS 10909 ** 10910 ** Applications may also register custom tokenizer types. A tokenizer 10911 ** is registered by providing fts5 with a populated instance of the 10912 ** following structure. All structure methods must be defined, setting 10913 ** any member of the fts5_tokenizer struct to NULL leads to undefined 10914 ** behaviour. The structure methods are expected to function as follows: 10915 ** 10916 ** xCreate: 10917 ** This function is used to allocate and initialize a tokenizer instance. 10918 ** A tokenizer instance is required to actually tokenize text. 10919 ** 10920 ** The first argument passed to this function is a copy of the (void*) 10921 ** pointer provided by the application when the fts5_tokenizer object 10922 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 10923 ** The second and third arguments are an array of nul-terminated strings 10924 ** containing the tokenizer arguments, if any, specified following the 10925 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 10926 ** to create the FTS5 table. 10927 ** 10928 ** The final argument is an output variable. If successful, (*ppOut) 10929 ** should be set to point to the new tokenizer handle and SQLITE_OK 10930 ** returned. If an error occurs, some value other than SQLITE_OK should 10931 ** be returned. In this case, fts5 assumes that the final value of *ppOut 10932 ** is undefined. 10933 ** 10934 ** xDelete: 10935 ** This function is invoked to delete a tokenizer handle previously 10936 ** allocated using xCreate(). Fts5 guarantees that this function will 10937 ** be invoked exactly once for each successful call to xCreate(). 10938 ** 10939 ** xTokenize: 10940 ** This function is expected to tokenize the nText byte string indicated 10941 ** by argument pText. pText may or may not be nul-terminated. The first 10942 ** argument passed to this function is a pointer to an Fts5Tokenizer object 10943 ** returned by an earlier call to xCreate(). 10944 ** 10945 ** The second argument indicates the reason that FTS5 is requesting 10946 ** tokenization of the supplied text. This is always one of the following 10947 ** four values: 10948 ** 10949 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 10950 ** or removed from the FTS table. The tokenizer is being invoked to 10951 ** determine the set of tokens to add to (or delete from) the 10952 ** FTS index. 10953 ** 10954 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 10955 ** against the FTS index. The tokenizer is being called to tokenize 10956 ** a bareword or quoted string specified as part of the query. 10957 ** 10958 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 10959 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 10960 ** followed by a "*" character, indicating that the last token 10961 ** returned by the tokenizer will be treated as a token prefix. 10962 ** 10963 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 10964 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 10965 ** function. Or an fts5_api.xColumnSize() request made by the same 10966 ** on a columnsize=0 database. 10967 ** </ul> 10968 ** 10969 ** For each token in the input string, the supplied callback xToken() must 10970 ** be invoked. The first argument to it should be a copy of the pointer 10971 ** passed as the second argument to xTokenize(). The third and fourth 10972 ** arguments are a pointer to a buffer containing the token text, and the 10973 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 10974 ** of the first byte of and first byte immediately following the text from 10975 ** which the token is derived within the input. 10976 ** 10977 ** The second argument passed to the xToken() callback ("tflags") should 10978 ** normally be set to 0. The exception is if the tokenizer supports 10979 ** synonyms. In this case see the discussion below for details. 10980 ** 10981 ** FTS5 assumes the xToken() callback is invoked for each token in the 10982 ** order that they occur within the input text. 10983 ** 10984 ** If an xToken() callback returns any value other than SQLITE_OK, then 10985 ** the tokenization should be abandoned and the xTokenize() method should 10986 ** immediately return a copy of the xToken() return value. Or, if the 10987 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 10988 ** if an error occurs with the xTokenize() implementation itself, it 10989 ** may abandon the tokenization and return any error code other than 10990 ** SQLITE_OK or SQLITE_DONE. 10991 ** 10992 ** SYNONYM SUPPORT 10993 ** 10994 ** Custom tokenizers may also support synonyms. Consider a case in which a 10995 ** user wishes to query for a phrase such as "first place". Using the 10996 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 10997 ** of "first place" within the document set, but not alternative forms 10998 ** such as "1st place". In some applications, it would be better to match 10999 ** all instances of "first place" or "1st place" regardless of which form 11000 ** the user specified in the MATCH query text. 11001 ** 11002 ** There are several ways to approach this in FTS5: 11003 ** 11004 ** <ol><li> By mapping all synonyms to a single token. In this case, the 11005 ** In the above example, this means that the tokenizer returns the 11006 ** same token for inputs "first" and "1st". Say that token is in 11007 ** fact "first", so that when the user inserts the document "I won 11008 ** 1st place" entries are added to the index for tokens "i", "won", 11009 ** "first" and "place". If the user then queries for '1st + place', 11010 ** the tokenizer substitutes "first" for "1st" and the query works 11011 ** as expected. 11012 ** 11013 ** <li> By adding multiple synonyms for a single term to the FTS index. 11014 ** In this case, when tokenizing query text, the tokenizer may 11015 ** provide multiple synonyms for a single term within the document. 11016 ** FTS5 then queries the index for each synonym individually. For 11017 ** example, faced with the query: 11018 ** 11019 ** <codeblock> 11020 ** ... MATCH 'first place'</codeblock> 11021 ** 11022 ** the tokenizer offers both "1st" and "first" as synonyms for the 11023 ** first token in the MATCH query and FTS5 effectively runs a query 11024 ** similar to: 11025 ** 11026 ** <codeblock> 11027 ** ... MATCH '(first OR 1st) place'</codeblock> 11028 ** 11029 ** except that, for the purposes of auxiliary functions, the query 11030 ** still appears to contain just two phrases - "(first OR 1st)" 11031 ** being treated as a single phrase. 11032 ** 11033 ** <li> By adding multiple synonyms for a single term to the FTS index. 11034 ** Using this method, when tokenizing document text, the tokenizer 11035 ** provides multiple synonyms for each token. So that when a 11036 ** document such as "I won first place" is tokenized, entries are 11037 ** added to the FTS index for "i", "won", "first", "1st" and 11038 ** "place". 11039 ** 11040 ** This way, even if the tokenizer does not provide synonyms 11041 ** when tokenizing query text (it should not - to do would be 11042 ** inefficient), it doesn't matter if the user queries for 11043 ** 'first + place' or '1st + place', as there are entires in the 11044 ** FTS index corresponding to both forms of the first token. 11045 ** </ol> 11046 ** 11047 ** Whether it is parsing document or query text, any call to xToken that 11048 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 11049 ** is considered to supply a synonym for the previous token. For example, 11050 ** when parsing the document "I won first place", a tokenizer that supports 11051 ** synonyms would call xToken() 5 times, as follows: 11052 ** 11053 ** <codeblock> 11054 ** xToken(pCtx, 0, "i", 1, 0, 1); 11055 ** xToken(pCtx, 0, "won", 3, 2, 5); 11056 ** xToken(pCtx, 0, "first", 5, 6, 11); 11057 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 11058 ** xToken(pCtx, 0, "place", 5, 12, 17); 11059 **</codeblock> 11060 ** 11061 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 11062 ** xToken() is called. Multiple synonyms may be specified for a single token 11063 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 11064 ** There is no limit to the number of synonyms that may be provided for a 11065 ** single token. 11066 ** 11067 ** In many cases, method (1) above is the best approach. It does not add 11068 ** extra data to the FTS index or require FTS5 to query for multiple terms, 11069 ** so it is efficient in terms of disk space and query speed. However, it 11070 ** does not support prefix queries very well. If, as suggested above, the 11071 ** token "first" is subsituted for "1st" by the tokenizer, then the query: 11072 ** 11073 ** <codeblock> 11074 ** ... MATCH '1s*'</codeblock> 11075 ** 11076 ** will not match documents that contain the token "1st" (as the tokenizer 11077 ** will probably not map "1s" to any prefix of "first"). 11078 ** 11079 ** For full prefix support, method (3) may be preferred. In this case, 11080 ** because the index contains entries for both "first" and "1st", prefix 11081 ** queries such as 'fi*' or '1s*' will match correctly. However, because 11082 ** extra entries are added to the FTS index, this method uses more space 11083 ** within the database. 11084 ** 11085 ** Method (2) offers a midpoint between (1) and (3). Using this method, 11086 ** a query such as '1s*' will match documents that contain the literal 11087 ** token "1st", but not "first" (assuming the tokenizer is not able to 11088 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 11089 ** will match against "1st" and "first". This method does not require 11090 ** extra disk space, as no extra entries are added to the FTS index. 11091 ** On the other hand, it may require more CPU cycles to run MATCH queries, 11092 ** as separate queries of the FTS index are required for each synonym. 11093 ** 11094 ** When using methods (2) or (3), it is important that the tokenizer only 11095 ** provide synonyms when tokenizing document text (method (2)) or query 11096 ** text (method (3)), not both. Doing so will not cause any errors, but is 11097 ** inefficient. 11098 */ 11099 typedef struct Fts5Tokenizer Fts5Tokenizer; 11100 typedef struct fts5_tokenizer fts5_tokenizer; 11101 struct fts5_tokenizer { 11102 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 11103 void (*xDelete)(Fts5Tokenizer*); 11104 int (*xTokenize)(Fts5Tokenizer*, 11105 void *pCtx, 11106 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 11107 const char *pText, int nText, 11108 int (*xToken)( 11109 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 11110 int tflags, /* Mask of FTS5_TOKEN_* flags */ 11111 const char *pToken, /* Pointer to buffer containing token */ 11112 int nToken, /* Size of token in bytes */ 11113 int iStart, /* Byte offset of token within input text */ 11114 int iEnd /* Byte offset of end of token within input text */ 11115 ) 11116 ); 11117 }; 11118 11119 /* Flags that may be passed as the third argument to xTokenize() */ 11120 #define FTS5_TOKENIZE_QUERY 0x0001 11121 #define FTS5_TOKENIZE_PREFIX 0x0002 11122 #define FTS5_TOKENIZE_DOCUMENT 0x0004 11123 #define FTS5_TOKENIZE_AUX 0x0008 11124 11125 /* Flags that may be passed by the tokenizer implementation back to FTS5 11126 ** as the third argument to the supplied xToken callback. */ 11127 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 11128 11129 /* 11130 ** END OF CUSTOM TOKENIZERS 11131 *************************************************************************/ 11132 11133 /************************************************************************* 11134 ** FTS5 EXTENSION REGISTRATION API 11135 */ 11136 typedef struct fts5_api fts5_api; 11137 struct fts5_api { 11138 int iVersion; /* Currently always set to 2 */ 11139 11140 /* Create a new tokenizer */ 11141 int (*xCreateTokenizer)( 11142 fts5_api *pApi, 11143 const char *zName, 11144 void *pContext, 11145 fts5_tokenizer *pTokenizer, 11146 void (*xDestroy)(void*) 11147 ); 11148 11149 /* Find an existing tokenizer */ 11150 int (*xFindTokenizer)( 11151 fts5_api *pApi, 11152 const char *zName, 11153 void **ppContext, 11154 fts5_tokenizer *pTokenizer 11155 ); 11156 11157 /* Create a new auxiliary function */ 11158 int (*xCreateFunction)( 11159 fts5_api *pApi, 11160 const char *zName, 11161 void *pContext, 11162 fts5_extension_function xFunction, 11163 void (*xDestroy)(void*) 11164 ); 11165 }; 11166 11167 /* 11168 ** END OF REGISTRATION API 11169 *************************************************************************/ 11170 11171 #ifdef __cplusplus 11172 } /* end of the 'extern "C"' block */ 11173 #endif 11174 11175 #endif /* _FTS5_H */ 11176 11177 /******** End of fts5.h *********/ 11178