1 /* 2 ** 2001 September 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_STDCALL 58 # define SQLITE_STDCALL 59 #endif 60 61 /* 62 ** These no-op macros are used in front of interfaces to mark those 63 ** interfaces as either deprecated or experimental. New applications 64 ** should not use deprecated interfaces - they are supported for backwards 65 ** compatibility only. Application writers should be aware that 66 ** experimental interfaces are subject to change in point releases. 67 ** 68 ** These macros used to resolve to various kinds of compiler magic that 69 ** would generate warning messages when they were used. But that 70 ** compiler magic ended up generating such a flurry of bug reports 71 ** that we have taken it all out and gone back to using simple 72 ** noop macros. 73 */ 74 #define SQLITE_DEPRECATED 75 #define SQLITE_EXPERIMENTAL 76 77 /* 78 ** Ensure these symbols were not defined by some previous header file. 79 */ 80 #ifdef SQLITE_VERSION 81 # undef SQLITE_VERSION 82 #endif 83 #ifdef SQLITE_VERSION_NUMBER 84 # undef SQLITE_VERSION_NUMBER 85 #endif 86 87 /* 88 ** CAPI3REF: Compile-Time Library Version Numbers 89 ** 90 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 91 ** evaluates to a string literal that is the SQLite version in the 92 ** format "X.Y.Z" where X is the major version number (always 3 for 93 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 94 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 95 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 96 ** numbers used in [SQLITE_VERSION].)^ 97 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 98 ** be larger than the release from which it is derived. Either Y will 99 ** be held constant and Z will be incremented or else Y will be incremented 100 ** and Z will be reset to zero. 101 ** 102 ** Since version 3.6.18, SQLite source code has been stored in the 103 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 104 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 105 ** a string which identifies a particular check-in of SQLite 106 ** within its configuration management system. ^The SQLITE_SOURCE_ID 107 ** string contains the date and time of the check-in (UTC) and an SHA1 108 ** hash of the entire source tree. 109 ** 110 ** See also: [sqlite3_libversion()], 111 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 112 ** [sqlite_version()] and [sqlite_source_id()]. 113 */ 114 #define SQLITE_VERSION "3.12.1" 115 #define SQLITE_VERSION_NUMBER 3012001 116 #define SQLITE_SOURCE_ID "2016-04-08 15:09:49 fe7d3b75fe1bde41511b323925af8ae1b910bc4d" 117 118 /* 119 ** CAPI3REF: Run-Time Library Version Numbers 120 ** KEYWORDS: sqlite3_version, sqlite3_sourceid 121 ** 122 ** These interfaces provide the same information as the [SQLITE_VERSION], 123 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 124 ** but are associated with the library instead of the header file. ^(Cautious 125 ** programmers might include assert() statements in their application to 126 ** verify that values returned by these interfaces match the macros in 127 ** the header, and thus ensure that the application is 128 ** compiled with matching library and header files. 129 ** 130 ** <blockquote><pre> 131 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 132 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 133 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 134 ** </pre></blockquote>)^ 135 ** 136 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 137 ** macro. ^The sqlite3_libversion() function returns a pointer to the 138 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 139 ** function is provided for use in DLLs since DLL users usually do not have 140 ** direct access to string constants within the DLL. ^The 141 ** sqlite3_libversion_number() function returns an integer equal to 142 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 143 ** a pointer to a string constant whose value is the same as the 144 ** [SQLITE_SOURCE_ID] C preprocessor macro. 145 ** 146 ** See also: [sqlite_version()] and [sqlite_source_id()]. 147 */ 148 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 149 SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void); 150 SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void); 151 SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void); 152 153 /* 154 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 155 ** 156 ** ^The sqlite3_compileoption_used() function returns 0 or 1 157 ** indicating whether the specified option was defined at 158 ** compile time. ^The SQLITE_ prefix may be omitted from the 159 ** option name passed to sqlite3_compileoption_used(). 160 ** 161 ** ^The sqlite3_compileoption_get() function allows iterating 162 ** over the list of options that were defined at compile time by 163 ** returning the N-th compile time option string. ^If N is out of range, 164 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 165 ** prefix is omitted from any strings returned by 166 ** sqlite3_compileoption_get(). 167 ** 168 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 169 ** and sqlite3_compileoption_get() may be omitted by specifying the 170 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 171 ** 172 ** See also: SQL functions [sqlite_compileoption_used()] and 173 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 174 */ 175 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 176 SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName); 177 SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N); 178 #endif 179 180 /* 181 ** CAPI3REF: Test To See If The Library Is Threadsafe 182 ** 183 ** ^The sqlite3_threadsafe() function returns zero if and only if 184 ** SQLite was compiled with mutexing code omitted due to the 185 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 186 ** 187 ** SQLite can be compiled with or without mutexes. When 188 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 189 ** are enabled and SQLite is threadsafe. When the 190 ** [SQLITE_THREADSAFE] macro is 0, 191 ** the mutexes are omitted. Without the mutexes, it is not safe 192 ** to use SQLite concurrently from more than one thread. 193 ** 194 ** Enabling mutexes incurs a measurable performance penalty. 195 ** So if speed is of utmost importance, it makes sense to disable 196 ** the mutexes. But for maximum safety, mutexes should be enabled. 197 ** ^The default behavior is for mutexes to be enabled. 198 ** 199 ** This interface can be used by an application to make sure that the 200 ** version of SQLite that it is linking against was compiled with 201 ** the desired setting of the [SQLITE_THREADSAFE] macro. 202 ** 203 ** This interface only reports on the compile-time mutex setting 204 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 205 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 206 ** can be fully or partially disabled using a call to [sqlite3_config()] 207 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 208 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 209 ** sqlite3_threadsafe() function shows only the compile-time setting of 210 ** thread safety, not any run-time changes to that setting made by 211 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 212 ** is unchanged by calls to sqlite3_config().)^ 213 ** 214 ** See the [threading mode] documentation for additional information. 215 */ 216 SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void); 217 218 /* 219 ** CAPI3REF: Database Connection Handle 220 ** KEYWORDS: {database connection} {database connections} 221 ** 222 ** Each open SQLite database is represented by a pointer to an instance of 223 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 224 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 225 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 226 ** and [sqlite3_close_v2()] are its destructors. There are many other 227 ** interfaces (such as 228 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 229 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 230 ** sqlite3 object. 231 */ 232 typedef struct sqlite3 sqlite3; 233 234 /* 235 ** CAPI3REF: 64-Bit Integer Types 236 ** KEYWORDS: sqlite_int64 sqlite_uint64 237 ** 238 ** Because there is no cross-platform way to specify 64-bit integer types 239 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 240 ** 241 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 242 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 243 ** compatibility only. 244 ** 245 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 246 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 247 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 248 ** between 0 and +18446744073709551615 inclusive. 249 */ 250 #ifdef SQLITE_INT64_TYPE 251 typedef SQLITE_INT64_TYPE sqlite_int64; 252 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 253 #elif defined(_MSC_VER) || defined(__BORLANDC__) 254 typedef __int64 sqlite_int64; 255 typedef unsigned __int64 sqlite_uint64; 256 #else 257 typedef long long int sqlite_int64; 258 typedef unsigned long long int sqlite_uint64; 259 #endif 260 typedef sqlite_int64 sqlite3_int64; 261 typedef sqlite_uint64 sqlite3_uint64; 262 263 /* 264 ** If compiling for a processor that lacks floating point support, 265 ** substitute integer for floating-point. 266 */ 267 #ifdef SQLITE_OMIT_FLOATING_POINT 268 # define double sqlite3_int64 269 #endif 270 271 /* 272 ** CAPI3REF: Closing A Database Connection 273 ** DESTRUCTOR: sqlite3 274 ** 275 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 276 ** for the [sqlite3] object. 277 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 278 ** the [sqlite3] object is successfully destroyed and all associated 279 ** resources are deallocated. 280 ** 281 ** ^If the database connection is associated with unfinalized prepared 282 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 283 ** will leave the database connection open and return [SQLITE_BUSY]. 284 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 285 ** and/or unfinished sqlite3_backups, then the database connection becomes 286 ** an unusable "zombie" which will automatically be deallocated when the 287 ** last prepared statement is finalized or the last sqlite3_backup is 288 ** finished. The sqlite3_close_v2() interface is intended for use with 289 ** host languages that are garbage collected, and where the order in which 290 ** destructors are called is arbitrary. 291 ** 292 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 293 ** [sqlite3_blob_close | close] all [BLOB handles], and 294 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 295 ** with the [sqlite3] object prior to attempting to close the object. ^If 296 ** sqlite3_close_v2() is called on a [database connection] that still has 297 ** outstanding [prepared statements], [BLOB handles], and/or 298 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 299 ** of resources is deferred until all [prepared statements], [BLOB handles], 300 ** and [sqlite3_backup] objects are also destroyed. 301 ** 302 ** ^If an [sqlite3] object is destroyed while a transaction is open, 303 ** the transaction is automatically rolled back. 304 ** 305 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 306 ** must be either a NULL 307 ** pointer or an [sqlite3] object pointer obtained 308 ** from [sqlite3_open()], [sqlite3_open16()], or 309 ** [sqlite3_open_v2()], and not previously closed. 310 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 311 ** argument is a harmless no-op. 312 */ 313 SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*); 314 SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*); 315 316 /* 317 ** The type for a callback function. 318 ** This is legacy and deprecated. It is included for historical 319 ** compatibility and is not documented. 320 */ 321 typedef int (*sqlite3_callback)(void*,int,char**, char**); 322 323 /* 324 ** CAPI3REF: One-Step Query Execution Interface 325 ** METHOD: sqlite3 326 ** 327 ** The sqlite3_exec() interface is a convenience wrapper around 328 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 329 ** that allows an application to run multiple statements of SQL 330 ** without having to use a lot of C code. 331 ** 332 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 333 ** semicolon-separate SQL statements passed into its 2nd argument, 334 ** in the context of the [database connection] passed in as its 1st 335 ** argument. ^If the callback function of the 3rd argument to 336 ** sqlite3_exec() is not NULL, then it is invoked for each result row 337 ** coming out of the evaluated SQL statements. ^The 4th argument to 338 ** sqlite3_exec() is relayed through to the 1st argument of each 339 ** callback invocation. ^If the callback pointer to sqlite3_exec() 340 ** is NULL, then no callback is ever invoked and result rows are 341 ** ignored. 342 ** 343 ** ^If an error occurs while evaluating the SQL statements passed into 344 ** sqlite3_exec(), then execution of the current statement stops and 345 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 346 ** is not NULL then any error message is written into memory obtained 347 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 348 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 349 ** on error message strings returned through the 5th parameter of 350 ** sqlite3_exec() after the error message string is no longer needed. 351 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 352 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 353 ** NULL before returning. 354 ** 355 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 356 ** routine returns SQLITE_ABORT without invoking the callback again and 357 ** without running any subsequent SQL statements. 358 ** 359 ** ^The 2nd argument to the sqlite3_exec() callback function is the 360 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 361 ** callback is an array of pointers to strings obtained as if from 362 ** [sqlite3_column_text()], one for each column. ^If an element of a 363 ** result row is NULL then the corresponding string pointer for the 364 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 365 ** sqlite3_exec() callback is an array of pointers to strings where each 366 ** entry represents the name of corresponding result column as obtained 367 ** from [sqlite3_column_name()]. 368 ** 369 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 370 ** to an empty string, or a pointer that contains only whitespace and/or 371 ** SQL comments, then no SQL statements are evaluated and the database 372 ** is not changed. 373 ** 374 ** Restrictions: 375 ** 376 ** <ul> 377 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 378 ** is a valid and open [database connection]. 379 ** <li> The application must not close the [database connection] specified by 380 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 381 ** <li> The application must not modify the SQL statement text passed into 382 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 383 ** </ul> 384 */ 385 SQLITE_API int SQLITE_STDCALL sqlite3_exec( 386 sqlite3*, /* An open database */ 387 const char *sql, /* SQL to be evaluated */ 388 int (*callback)(void*,int,char**,char**), /* Callback function */ 389 void *, /* 1st argument to callback */ 390 char **errmsg /* Error msg written here */ 391 ); 392 393 /* 394 ** CAPI3REF: Result Codes 395 ** KEYWORDS: {result code definitions} 396 ** 397 ** Many SQLite functions return an integer result code from the set shown 398 ** here in order to indicate success or failure. 399 ** 400 ** New error codes may be added in future versions of SQLite. 401 ** 402 ** See also: [extended result code definitions] 403 */ 404 #define SQLITE_OK 0 /* Successful result */ 405 /* beginning-of-error-codes */ 406 #define SQLITE_ERROR 1 /* SQL error or missing database */ 407 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 408 #define SQLITE_PERM 3 /* Access permission denied */ 409 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 410 #define SQLITE_BUSY 5 /* The database file is locked */ 411 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 412 #define SQLITE_NOMEM 7 /* A malloc() failed */ 413 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 414 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 415 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 416 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 417 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 418 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 419 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 420 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 421 #define SQLITE_EMPTY 16 /* Database is empty */ 422 #define SQLITE_SCHEMA 17 /* The database schema changed */ 423 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 424 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 425 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 426 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 427 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 428 #define SQLITE_AUTH 23 /* Authorization denied */ 429 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 430 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 431 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 432 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 433 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 434 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 435 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 436 /* end-of-error-codes */ 437 438 /* 439 ** CAPI3REF: Extended Result Codes 440 ** KEYWORDS: {extended result code definitions} 441 ** 442 ** In its default configuration, SQLite API routines return one of 30 integer 443 ** [result codes]. However, experience has shown that many of 444 ** these result codes are too coarse-grained. They do not provide as 445 ** much information about problems as programmers might like. In an effort to 446 ** address this, newer versions of SQLite (version 3.3.8 and later) include 447 ** support for additional result codes that provide more detailed information 448 ** about errors. These [extended result codes] are enabled or disabled 449 ** on a per database connection basis using the 450 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 451 ** the most recent error can be obtained using 452 ** [sqlite3_extended_errcode()]. 453 */ 454 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 455 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 456 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 457 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 458 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 459 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 460 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 461 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 462 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 463 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 464 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 465 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 466 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 467 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 468 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 469 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 470 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 471 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 472 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 473 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 474 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 475 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 476 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 477 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 478 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 479 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 480 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 481 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 482 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 483 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 484 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 485 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 486 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 487 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 488 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 489 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 490 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 491 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 492 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 493 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 494 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 495 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 496 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 497 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 498 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 499 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 500 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 501 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 502 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 503 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 504 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 505 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 506 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 507 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 508 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 509 510 /* 511 ** CAPI3REF: Flags For File Open Operations 512 ** 513 ** These bit values are intended for use in the 514 ** 3rd parameter to the [sqlite3_open_v2()] interface and 515 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 516 */ 517 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 518 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 519 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 520 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 521 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 522 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 523 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 524 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 525 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 526 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 527 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 528 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 529 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 530 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 531 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 532 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 533 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 534 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 535 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 536 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 537 538 /* Reserved: 0x00F00000 */ 539 540 /* 541 ** CAPI3REF: Device Characteristics 542 ** 543 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 544 ** object returns an integer which is a vector of these 545 ** bit values expressing I/O characteristics of the mass storage 546 ** device that holds the file that the [sqlite3_io_methods] 547 ** refers to. 548 ** 549 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 550 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 551 ** mean that writes of blocks that are nnn bytes in size and 552 ** are aligned to an address which is an integer multiple of 553 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 554 ** that when data is appended to a file, the data is appended 555 ** first then the size of the file is extended, never the other 556 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 557 ** information is written to disk in the same order as calls 558 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 559 ** after reboot following a crash or power loss, the only bytes in a 560 ** file that were written at the application level might have changed 561 ** and that adjacent bytes, even bytes within the same sector are 562 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 563 ** flag indicate that a file cannot be deleted when open. The 564 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 565 ** read-only media and cannot be changed even by processes with 566 ** elevated privileges. 567 */ 568 #define SQLITE_IOCAP_ATOMIC 0x00000001 569 #define SQLITE_IOCAP_ATOMIC512 0x00000002 570 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 571 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 572 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 573 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 574 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 575 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 576 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 577 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 578 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 579 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 580 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 581 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 582 583 /* 584 ** CAPI3REF: File Locking Levels 585 ** 586 ** SQLite uses one of these integer values as the second 587 ** argument to calls it makes to the xLock() and xUnlock() methods 588 ** of an [sqlite3_io_methods] object. 589 */ 590 #define SQLITE_LOCK_NONE 0 591 #define SQLITE_LOCK_SHARED 1 592 #define SQLITE_LOCK_RESERVED 2 593 #define SQLITE_LOCK_PENDING 3 594 #define SQLITE_LOCK_EXCLUSIVE 4 595 596 /* 597 ** CAPI3REF: Synchronization Type Flags 598 ** 599 ** When SQLite invokes the xSync() method of an 600 ** [sqlite3_io_methods] object it uses a combination of 601 ** these integer values as the second argument. 602 ** 603 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 604 ** sync operation only needs to flush data to mass storage. Inode 605 ** information need not be flushed. If the lower four bits of the flag 606 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 607 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 608 ** to use Mac OS X style fullsync instead of fsync(). 609 ** 610 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 611 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 612 ** settings. The [synchronous pragma] determines when calls to the 613 ** xSync VFS method occur and applies uniformly across all platforms. 614 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 615 ** energetic or rigorous or forceful the sync operations are and 616 ** only make a difference on Mac OSX for the default SQLite code. 617 ** (Third-party VFS implementations might also make the distinction 618 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 619 ** operating systems natively supported by SQLite, only Mac OSX 620 ** cares about the difference.) 621 */ 622 #define SQLITE_SYNC_NORMAL 0x00002 623 #define SQLITE_SYNC_FULL 0x00003 624 #define SQLITE_SYNC_DATAONLY 0x00010 625 626 /* 627 ** CAPI3REF: OS Interface Open File Handle 628 ** 629 ** An [sqlite3_file] object represents an open file in the 630 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 631 ** implementations will 632 ** want to subclass this object by appending additional fields 633 ** for their own use. The pMethods entry is a pointer to an 634 ** [sqlite3_io_methods] object that defines methods for performing 635 ** I/O operations on the open file. 636 */ 637 typedef struct sqlite3_file sqlite3_file; 638 struct sqlite3_file { 639 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 640 }; 641 642 /* 643 ** CAPI3REF: OS Interface File Virtual Methods Object 644 ** 645 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 646 ** [sqlite3_file] object (or, more commonly, a subclass of the 647 ** [sqlite3_file] object) with a pointer to an instance of this object. 648 ** This object defines the methods used to perform various operations 649 ** against the open file represented by the [sqlite3_file] object. 650 ** 651 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 652 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 653 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 654 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 655 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 656 ** to NULL. 657 ** 658 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 659 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 660 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 661 ** flag may be ORed in to indicate that only the data of the file 662 ** and not its inode needs to be synced. 663 ** 664 ** The integer values to xLock() and xUnlock() are one of 665 ** <ul> 666 ** <li> [SQLITE_LOCK_NONE], 667 ** <li> [SQLITE_LOCK_SHARED], 668 ** <li> [SQLITE_LOCK_RESERVED], 669 ** <li> [SQLITE_LOCK_PENDING], or 670 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 671 ** </ul> 672 ** xLock() increases the lock. xUnlock() decreases the lock. 673 ** The xCheckReservedLock() method checks whether any database connection, 674 ** either in this process or in some other process, is holding a RESERVED, 675 ** PENDING, or EXCLUSIVE lock on the file. It returns true 676 ** if such a lock exists and false otherwise. 677 ** 678 ** The xFileControl() method is a generic interface that allows custom 679 ** VFS implementations to directly control an open file using the 680 ** [sqlite3_file_control()] interface. The second "op" argument is an 681 ** integer opcode. The third argument is a generic pointer intended to 682 ** point to a structure that may contain arguments or space in which to 683 ** write return values. Potential uses for xFileControl() might be 684 ** functions to enable blocking locks with timeouts, to change the 685 ** locking strategy (for example to use dot-file locks), to inquire 686 ** about the status of a lock, or to break stale locks. The SQLite 687 ** core reserves all opcodes less than 100 for its own use. 688 ** A [file control opcodes | list of opcodes] less than 100 is available. 689 ** Applications that define a custom xFileControl method should use opcodes 690 ** greater than 100 to avoid conflicts. VFS implementations should 691 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 692 ** recognize. 693 ** 694 ** The xSectorSize() method returns the sector size of the 695 ** device that underlies the file. The sector size is the 696 ** minimum write that can be performed without disturbing 697 ** other bytes in the file. The xDeviceCharacteristics() 698 ** method returns a bit vector describing behaviors of the 699 ** underlying device: 700 ** 701 ** <ul> 702 ** <li> [SQLITE_IOCAP_ATOMIC] 703 ** <li> [SQLITE_IOCAP_ATOMIC512] 704 ** <li> [SQLITE_IOCAP_ATOMIC1K] 705 ** <li> [SQLITE_IOCAP_ATOMIC2K] 706 ** <li> [SQLITE_IOCAP_ATOMIC4K] 707 ** <li> [SQLITE_IOCAP_ATOMIC8K] 708 ** <li> [SQLITE_IOCAP_ATOMIC16K] 709 ** <li> [SQLITE_IOCAP_ATOMIC32K] 710 ** <li> [SQLITE_IOCAP_ATOMIC64K] 711 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 712 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 713 ** </ul> 714 ** 715 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 716 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 717 ** mean that writes of blocks that are nnn bytes in size and 718 ** are aligned to an address which is an integer multiple of 719 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 720 ** that when data is appended to a file, the data is appended 721 ** first then the size of the file is extended, never the other 722 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 723 ** information is written to disk in the same order as calls 724 ** to xWrite(). 725 ** 726 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 727 ** in the unread portions of the buffer with zeros. A VFS that 728 ** fails to zero-fill short reads might seem to work. However, 729 ** failure to zero-fill short reads will eventually lead to 730 ** database corruption. 731 */ 732 typedef struct sqlite3_io_methods sqlite3_io_methods; 733 struct sqlite3_io_methods { 734 int iVersion; 735 int (*xClose)(sqlite3_file*); 736 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 737 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 738 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 739 int (*xSync)(sqlite3_file*, int flags); 740 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 741 int (*xLock)(sqlite3_file*, int); 742 int (*xUnlock)(sqlite3_file*, int); 743 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 744 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 745 int (*xSectorSize)(sqlite3_file*); 746 int (*xDeviceCharacteristics)(sqlite3_file*); 747 /* Methods above are valid for version 1 */ 748 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 749 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 750 void (*xShmBarrier)(sqlite3_file*); 751 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 752 /* Methods above are valid for version 2 */ 753 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 754 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 755 /* Methods above are valid for version 3 */ 756 /* Additional methods may be added in future releases */ 757 }; 758 759 /* 760 ** CAPI3REF: Standard File Control Opcodes 761 ** KEYWORDS: {file control opcodes} {file control opcode} 762 ** 763 ** These integer constants are opcodes for the xFileControl method 764 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 765 ** interface. 766 ** 767 ** <ul> 768 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 769 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 770 ** opcode causes the xFileControl method to write the current state of 771 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 772 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 773 ** into an integer that the pArg argument points to. This capability 774 ** is used during testing and is only available when the SQLITE_TEST 775 ** compile-time option is used. 776 ** 777 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 778 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 779 ** layer a hint of how large the database file will grow to be during the 780 ** current transaction. This hint is not guaranteed to be accurate but it 781 ** is often close. The underlying VFS might choose to preallocate database 782 ** file space based on this hint in order to help writes to the database 783 ** file run faster. 784 ** 785 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 786 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 787 ** extends and truncates the database file in chunks of a size specified 788 ** by the user. The fourth argument to [sqlite3_file_control()] should 789 ** point to an integer (type int) containing the new chunk-size to use 790 ** for the nominated database. Allocating database file space in large 791 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 792 ** improve performance on some systems. 793 ** 794 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 795 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 796 ** to the [sqlite3_file] object associated with a particular database 797 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 798 ** 799 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 800 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 801 ** to the [sqlite3_file] object associated with the journal file (either 802 ** the [rollback journal] or the [write-ahead log]) for a particular database 803 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 804 ** 805 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 806 ** No longer in use. 807 ** 808 ** <li>[[SQLITE_FCNTL_SYNC]] 809 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 810 ** sent to the VFS immediately before the xSync method is invoked on a 811 ** database file descriptor. Or, if the xSync method is not invoked 812 ** because the user has configured SQLite with 813 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 814 ** of the xSync method. In most cases, the pointer argument passed with 815 ** this file-control is NULL. However, if the database file is being synced 816 ** as part of a multi-database commit, the argument points to a nul-terminated 817 ** string containing the transactions master-journal file name. VFSes that 818 ** do not need this signal should silently ignore this opcode. Applications 819 ** should not call [sqlite3_file_control()] with this opcode as doing so may 820 ** disrupt the operation of the specialized VFSes that do require it. 821 ** 822 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 823 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 824 ** and sent to the VFS after a transaction has been committed immediately 825 ** but before the database is unlocked. VFSes that do not need this signal 826 ** should silently ignore this opcode. Applications should not call 827 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 828 ** operation of the specialized VFSes that do require it. 829 ** 830 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 831 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 832 ** retry counts and intervals for certain disk I/O operations for the 833 ** windows [VFS] in order to provide robustness in the presence of 834 ** anti-virus programs. By default, the windows VFS will retry file read, 835 ** file write, and file delete operations up to 10 times, with a delay 836 ** of 25 milliseconds before the first retry and with the delay increasing 837 ** by an additional 25 milliseconds with each subsequent retry. This 838 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 839 ** to be adjusted. The values are changed for all database connections 840 ** within the same process. The argument is a pointer to an array of two 841 ** integers where the first integer i the new retry count and the second 842 ** integer is the delay. If either integer is negative, then the setting 843 ** is not changed but instead the prior value of that setting is written 844 ** into the array entry, allowing the current retry settings to be 845 ** interrogated. The zDbName parameter is ignored. 846 ** 847 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 848 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 849 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 850 ** write ahead log and shared memory files used for transaction control 851 ** are automatically deleted when the latest connection to the database 852 ** closes. Setting persistent WAL mode causes those files to persist after 853 ** close. Persisting the files is useful when other processes that do not 854 ** have write permission on the directory containing the database file want 855 ** to read the database file, as the WAL and shared memory files must exist 856 ** in order for the database to be readable. The fourth parameter to 857 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 858 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 859 ** WAL mode. If the integer is -1, then it is overwritten with the current 860 ** WAL persistence setting. 861 ** 862 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 863 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 864 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 865 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 866 ** xDeviceCharacteristics methods. The fourth parameter to 867 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 868 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 869 ** mode. If the integer is -1, then it is overwritten with the current 870 ** zero-damage mode setting. 871 ** 872 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 873 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 874 ** a write transaction to indicate that, unless it is rolled back for some 875 ** reason, the entire database file will be overwritten by the current 876 ** transaction. This is used by VACUUM operations. 877 ** 878 ** <li>[[SQLITE_FCNTL_VFSNAME]] 879 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 880 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 881 ** final bottom-level VFS are written into memory obtained from 882 ** [sqlite3_malloc()] and the result is stored in the char* variable 883 ** that the fourth parameter of [sqlite3_file_control()] points to. 884 ** The caller is responsible for freeing the memory when done. As with 885 ** all file-control actions, there is no guarantee that this will actually 886 ** do anything. Callers should initialize the char* variable to a NULL 887 ** pointer in case this file-control is not implemented. This file-control 888 ** is intended for diagnostic use only. 889 ** 890 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 891 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 892 ** [VFSes] currently in use. ^(The argument X in 893 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 894 ** of type "[sqlite3_vfs] **". This opcodes will set *X 895 ** to a pointer to the top-level VFS.)^ 896 ** ^When there are multiple VFS shims in the stack, this opcode finds the 897 ** upper-most shim only. 898 ** 899 ** <li>[[SQLITE_FCNTL_PRAGMA]] 900 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 901 ** file control is sent to the open [sqlite3_file] object corresponding 902 ** to the database file to which the pragma statement refers. ^The argument 903 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 904 ** pointers to strings (char**) in which the second element of the array 905 ** is the name of the pragma and the third element is the argument to the 906 ** pragma or NULL if the pragma has no argument. ^The handler for an 907 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 908 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 909 ** or the equivalent and that string will become the result of the pragma or 910 ** the error message if the pragma fails. ^If the 911 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 912 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 913 ** file control returns [SQLITE_OK], then the parser assumes that the 914 ** VFS has handled the PRAGMA itself and the parser generates a no-op 915 ** prepared statement if result string is NULL, or that returns a copy 916 ** of the result string if the string is non-NULL. 917 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 918 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 919 ** that the VFS encountered an error while handling the [PRAGMA] and the 920 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 921 ** file control occurs at the beginning of pragma statement analysis and so 922 ** it is able to override built-in [PRAGMA] statements. 923 ** 924 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 925 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 926 ** file-control may be invoked by SQLite on the database file handle 927 ** shortly after it is opened in order to provide a custom VFS with access 928 ** to the connections busy-handler callback. The argument is of type (void **) 929 ** - an array of two (void *) values. The first (void *) actually points 930 ** to a function of type (int (*)(void *)). In order to invoke the connections 931 ** busy-handler, this function should be invoked with the second (void *) in 932 ** the array as the only argument. If it returns non-zero, then the operation 933 ** should be retried. If it returns zero, the custom VFS should abandon the 934 ** current operation. 935 ** 936 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 937 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 938 ** to have SQLite generate a 939 ** temporary filename using the same algorithm that is followed to generate 940 ** temporary filenames for TEMP tables and other internal uses. The 941 ** argument should be a char** which will be filled with the filename 942 ** written into memory obtained from [sqlite3_malloc()]. The caller should 943 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 944 ** 945 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 946 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 947 ** maximum number of bytes that will be used for memory-mapped I/O. 948 ** The argument is a pointer to a value of type sqlite3_int64 that 949 ** is an advisory maximum number of bytes in the file to memory map. The 950 ** pointer is overwritten with the old value. The limit is not changed if 951 ** the value originally pointed to is negative, and so the current limit 952 ** can be queried by passing in a pointer to a negative number. This 953 ** file-control is used internally to implement [PRAGMA mmap_size]. 954 ** 955 ** <li>[[SQLITE_FCNTL_TRACE]] 956 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 957 ** to the VFS about what the higher layers of the SQLite stack are doing. 958 ** This file control is used by some VFS activity tracing [shims]. 959 ** The argument is a zero-terminated string. Higher layers in the 960 ** SQLite stack may generate instances of this file control if 961 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 962 ** 963 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 964 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 965 ** pointer to an integer and it writes a boolean into that integer depending 966 ** on whether or not the file has been renamed, moved, or deleted since it 967 ** was first opened. 968 ** 969 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 970 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 971 ** opcode causes the xFileControl method to swap the file handle with the one 972 ** pointed to by the pArg argument. This capability is used during testing 973 ** and only needs to be supported when SQLITE_TEST is defined. 974 ** 975 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 976 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 977 ** be advantageous to block on the next WAL lock if the lock is not immediately 978 ** available. The WAL subsystem issues this signal during rare 979 ** circumstances in order to fix a problem with priority inversion. 980 ** Applications should <em>not</em> use this file-control. 981 ** 982 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 983 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 984 ** VFS should return SQLITE_NOTFOUND for this opcode. 985 ** 986 ** <li>[[SQLITE_FCNTL_RBU]] 987 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 988 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 989 ** this opcode. 990 ** </ul> 991 */ 992 #define SQLITE_FCNTL_LOCKSTATE 1 993 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 994 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 995 #define SQLITE_FCNTL_LAST_ERRNO 4 996 #define SQLITE_FCNTL_SIZE_HINT 5 997 #define SQLITE_FCNTL_CHUNK_SIZE 6 998 #define SQLITE_FCNTL_FILE_POINTER 7 999 #define SQLITE_FCNTL_SYNC_OMITTED 8 1000 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1001 #define SQLITE_FCNTL_PERSIST_WAL 10 1002 #define SQLITE_FCNTL_OVERWRITE 11 1003 #define SQLITE_FCNTL_VFSNAME 12 1004 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1005 #define SQLITE_FCNTL_PRAGMA 14 1006 #define SQLITE_FCNTL_BUSYHANDLER 15 1007 #define SQLITE_FCNTL_TEMPFILENAME 16 1008 #define SQLITE_FCNTL_MMAP_SIZE 18 1009 #define SQLITE_FCNTL_TRACE 19 1010 #define SQLITE_FCNTL_HAS_MOVED 20 1011 #define SQLITE_FCNTL_SYNC 21 1012 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1013 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1014 #define SQLITE_FCNTL_WAL_BLOCK 24 1015 #define SQLITE_FCNTL_ZIPVFS 25 1016 #define SQLITE_FCNTL_RBU 26 1017 #define SQLITE_FCNTL_VFS_POINTER 27 1018 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1019 1020 /* deprecated names */ 1021 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1022 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1023 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1024 1025 1026 /* 1027 ** CAPI3REF: Mutex Handle 1028 ** 1029 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1030 ** abstract type for a mutex object. The SQLite core never looks 1031 ** at the internal representation of an [sqlite3_mutex]. It only 1032 ** deals with pointers to the [sqlite3_mutex] object. 1033 ** 1034 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1035 */ 1036 typedef struct sqlite3_mutex sqlite3_mutex; 1037 1038 /* 1039 ** CAPI3REF: OS Interface Object 1040 ** 1041 ** An instance of the sqlite3_vfs object defines the interface between 1042 ** the SQLite core and the underlying operating system. The "vfs" 1043 ** in the name of the object stands for "virtual file system". See 1044 ** the [VFS | VFS documentation] for further information. 1045 ** 1046 ** The value of the iVersion field is initially 1 but may be larger in 1047 ** future versions of SQLite. Additional fields may be appended to this 1048 ** object when the iVersion value is increased. Note that the structure 1049 ** of the sqlite3_vfs object changes in the transaction between 1050 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1051 ** modified. 1052 ** 1053 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1054 ** structure used by this VFS. mxPathname is the maximum length of 1055 ** a pathname in this VFS. 1056 ** 1057 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1058 ** the pNext pointer. The [sqlite3_vfs_register()] 1059 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1060 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1061 ** searches the list. Neither the application code nor the VFS 1062 ** implementation should use the pNext pointer. 1063 ** 1064 ** The pNext field is the only field in the sqlite3_vfs 1065 ** structure that SQLite will ever modify. SQLite will only access 1066 ** or modify this field while holding a particular static mutex. 1067 ** The application should never modify anything within the sqlite3_vfs 1068 ** object once the object has been registered. 1069 ** 1070 ** The zName field holds the name of the VFS module. The name must 1071 ** be unique across all VFS modules. 1072 ** 1073 ** [[sqlite3_vfs.xOpen]] 1074 ** ^SQLite guarantees that the zFilename parameter to xOpen 1075 ** is either a NULL pointer or string obtained 1076 ** from xFullPathname() with an optional suffix added. 1077 ** ^If a suffix is added to the zFilename parameter, it will 1078 ** consist of a single "-" character followed by no more than 1079 ** 11 alphanumeric and/or "-" characters. 1080 ** ^SQLite further guarantees that 1081 ** the string will be valid and unchanged until xClose() is 1082 ** called. Because of the previous sentence, 1083 ** the [sqlite3_file] can safely store a pointer to the 1084 ** filename if it needs to remember the filename for some reason. 1085 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1086 ** must invent its own temporary name for the file. ^Whenever the 1087 ** xFilename parameter is NULL it will also be the case that the 1088 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1089 ** 1090 ** The flags argument to xOpen() includes all bits set in 1091 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1092 ** or [sqlite3_open16()] is used, then flags includes at least 1093 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1094 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1095 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1096 ** 1097 ** ^(SQLite will also add one of the following flags to the xOpen() 1098 ** call, depending on the object being opened: 1099 ** 1100 ** <ul> 1101 ** <li> [SQLITE_OPEN_MAIN_DB] 1102 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1103 ** <li> [SQLITE_OPEN_TEMP_DB] 1104 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1105 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1106 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1107 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1108 ** <li> [SQLITE_OPEN_WAL] 1109 ** </ul>)^ 1110 ** 1111 ** The file I/O implementation can use the object type flags to 1112 ** change the way it deals with files. For example, an application 1113 ** that does not care about crash recovery or rollback might make 1114 ** the open of a journal file a no-op. Writes to this journal would 1115 ** also be no-ops, and any attempt to read the journal would return 1116 ** SQLITE_IOERR. Or the implementation might recognize that a database 1117 ** file will be doing page-aligned sector reads and writes in a random 1118 ** order and set up its I/O subsystem accordingly. 1119 ** 1120 ** SQLite might also add one of the following flags to the xOpen method: 1121 ** 1122 ** <ul> 1123 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1124 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1125 ** </ul> 1126 ** 1127 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1128 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1129 ** will be set for TEMP databases and their journals, transient 1130 ** databases, and subjournals. 1131 ** 1132 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1133 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1134 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1135 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1136 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1137 ** be created, and that it is an error if it already exists. 1138 ** It is <i>not</i> used to indicate the file should be opened 1139 ** for exclusive access. 1140 ** 1141 ** ^At least szOsFile bytes of memory are allocated by SQLite 1142 ** to hold the [sqlite3_file] structure passed as the third 1143 ** argument to xOpen. The xOpen method does not have to 1144 ** allocate the structure; it should just fill it in. Note that 1145 ** the xOpen method must set the sqlite3_file.pMethods to either 1146 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1147 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1148 ** element will be valid after xOpen returns regardless of the success 1149 ** or failure of the xOpen call. 1150 ** 1151 ** [[sqlite3_vfs.xAccess]] 1152 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1153 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1154 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1155 ** to test whether a file is at least readable. The file can be a 1156 ** directory. 1157 ** 1158 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1159 ** output buffer xFullPathname. The exact size of the output buffer 1160 ** is also passed as a parameter to both methods. If the output buffer 1161 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1162 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1163 ** to prevent this by setting mxPathname to a sufficiently large value. 1164 ** 1165 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1166 ** interfaces are not strictly a part of the filesystem, but they are 1167 ** included in the VFS structure for completeness. 1168 ** The xRandomness() function attempts to return nBytes bytes 1169 ** of good-quality randomness into zOut. The return value is 1170 ** the actual number of bytes of randomness obtained. 1171 ** The xSleep() method causes the calling thread to sleep for at 1172 ** least the number of microseconds given. ^The xCurrentTime() 1173 ** method returns a Julian Day Number for the current date and time as 1174 ** a floating point value. 1175 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1176 ** Day Number multiplied by 86400000 (the number of milliseconds in 1177 ** a 24-hour day). 1178 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1179 ** date and time if that method is available (if iVersion is 2 or 1180 ** greater and the function pointer is not NULL) and will fall back 1181 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1182 ** 1183 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1184 ** are not used by the SQLite core. These optional interfaces are provided 1185 ** by some VFSes to facilitate testing of the VFS code. By overriding 1186 ** system calls with functions under its control, a test program can 1187 ** simulate faults and error conditions that would otherwise be difficult 1188 ** or impossible to induce. The set of system calls that can be overridden 1189 ** varies from one VFS to another, and from one version of the same VFS to the 1190 ** next. Applications that use these interfaces must be prepared for any 1191 ** or all of these interfaces to be NULL or for their behavior to change 1192 ** from one release to the next. Applications must not attempt to access 1193 ** any of these methods if the iVersion of the VFS is less than 3. 1194 */ 1195 typedef struct sqlite3_vfs sqlite3_vfs; 1196 typedef void (*sqlite3_syscall_ptr)(void); 1197 struct sqlite3_vfs { 1198 int iVersion; /* Structure version number (currently 3) */ 1199 int szOsFile; /* Size of subclassed sqlite3_file */ 1200 int mxPathname; /* Maximum file pathname length */ 1201 sqlite3_vfs *pNext; /* Next registered VFS */ 1202 const char *zName; /* Name of this virtual file system */ 1203 void *pAppData; /* Pointer to application-specific data */ 1204 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1205 int flags, int *pOutFlags); 1206 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1207 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1208 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1209 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1210 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1211 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1212 void (*xDlClose)(sqlite3_vfs*, void*); 1213 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1214 int (*xSleep)(sqlite3_vfs*, int microseconds); 1215 int (*xCurrentTime)(sqlite3_vfs*, double*); 1216 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1217 /* 1218 ** The methods above are in version 1 of the sqlite_vfs object 1219 ** definition. Those that follow are added in version 2 or later 1220 */ 1221 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1222 /* 1223 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1224 ** Those below are for version 3 and greater. 1225 */ 1226 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1227 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1228 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1229 /* 1230 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1231 ** New fields may be appended in future versions. The iVersion 1232 ** value will increment whenever this happens. 1233 */ 1234 }; 1235 1236 /* 1237 ** CAPI3REF: Flags for the xAccess VFS method 1238 ** 1239 ** These integer constants can be used as the third parameter to 1240 ** the xAccess method of an [sqlite3_vfs] object. They determine 1241 ** what kind of permissions the xAccess method is looking for. 1242 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1243 ** simply checks whether the file exists. 1244 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1245 ** checks whether the named directory is both readable and writable 1246 ** (in other words, if files can be added, removed, and renamed within 1247 ** the directory). 1248 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1249 ** [temp_store_directory pragma], though this could change in a future 1250 ** release of SQLite. 1251 ** With SQLITE_ACCESS_READ, the xAccess method 1252 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1253 ** currently unused, though it might be used in a future release of 1254 ** SQLite. 1255 */ 1256 #define SQLITE_ACCESS_EXISTS 0 1257 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1258 #define SQLITE_ACCESS_READ 2 /* Unused */ 1259 1260 /* 1261 ** CAPI3REF: Flags for the xShmLock VFS method 1262 ** 1263 ** These integer constants define the various locking operations 1264 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1265 ** following are the only legal combinations of flags to the 1266 ** xShmLock method: 1267 ** 1268 ** <ul> 1269 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1270 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1271 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1272 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1273 ** </ul> 1274 ** 1275 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1276 ** was given on the corresponding lock. 1277 ** 1278 ** The xShmLock method can transition between unlocked and SHARED or 1279 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1280 ** and EXCLUSIVE. 1281 */ 1282 #define SQLITE_SHM_UNLOCK 1 1283 #define SQLITE_SHM_LOCK 2 1284 #define SQLITE_SHM_SHARED 4 1285 #define SQLITE_SHM_EXCLUSIVE 8 1286 1287 /* 1288 ** CAPI3REF: Maximum xShmLock index 1289 ** 1290 ** The xShmLock method on [sqlite3_io_methods] may use values 1291 ** between 0 and this upper bound as its "offset" argument. 1292 ** The SQLite core will never attempt to acquire or release a 1293 ** lock outside of this range 1294 */ 1295 #define SQLITE_SHM_NLOCK 8 1296 1297 1298 /* 1299 ** CAPI3REF: Initialize The SQLite Library 1300 ** 1301 ** ^The sqlite3_initialize() routine initializes the 1302 ** SQLite library. ^The sqlite3_shutdown() routine 1303 ** deallocates any resources that were allocated by sqlite3_initialize(). 1304 ** These routines are designed to aid in process initialization and 1305 ** shutdown on embedded systems. Workstation applications using 1306 ** SQLite normally do not need to invoke either of these routines. 1307 ** 1308 ** A call to sqlite3_initialize() is an "effective" call if it is 1309 ** the first time sqlite3_initialize() is invoked during the lifetime of 1310 ** the process, or if it is the first time sqlite3_initialize() is invoked 1311 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1312 ** of sqlite3_initialize() does any initialization. All other calls 1313 ** are harmless no-ops.)^ 1314 ** 1315 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1316 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1317 ** an effective call to sqlite3_shutdown() does any deinitialization. 1318 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1319 ** 1320 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1321 ** is not. The sqlite3_shutdown() interface must only be called from a 1322 ** single thread. All open [database connections] must be closed and all 1323 ** other SQLite resources must be deallocated prior to invoking 1324 ** sqlite3_shutdown(). 1325 ** 1326 ** Among other things, ^sqlite3_initialize() will invoke 1327 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1328 ** will invoke sqlite3_os_end(). 1329 ** 1330 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1331 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1332 ** the library (perhaps it is unable to allocate a needed resource such 1333 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1334 ** 1335 ** ^The sqlite3_initialize() routine is called internally by many other 1336 ** SQLite interfaces so that an application usually does not need to 1337 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1338 ** calls sqlite3_initialize() so the SQLite library will be automatically 1339 ** initialized when [sqlite3_open()] is called if it has not be initialized 1340 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1341 ** compile-time option, then the automatic calls to sqlite3_initialize() 1342 ** are omitted and the application must call sqlite3_initialize() directly 1343 ** prior to using any other SQLite interface. For maximum portability, 1344 ** it is recommended that applications always invoke sqlite3_initialize() 1345 ** directly prior to using any other SQLite interface. Future releases 1346 ** of SQLite may require this. In other words, the behavior exhibited 1347 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1348 ** default behavior in some future release of SQLite. 1349 ** 1350 ** The sqlite3_os_init() routine does operating-system specific 1351 ** initialization of the SQLite library. The sqlite3_os_end() 1352 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1353 ** performed by these routines include allocation or deallocation 1354 ** of static resources, initialization of global variables, 1355 ** setting up a default [sqlite3_vfs] module, or setting up 1356 ** a default configuration using [sqlite3_config()]. 1357 ** 1358 ** The application should never invoke either sqlite3_os_init() 1359 ** or sqlite3_os_end() directly. The application should only invoke 1360 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1361 ** interface is called automatically by sqlite3_initialize() and 1362 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1363 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1364 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1365 ** When [custom builds | built for other platforms] 1366 ** (using the [SQLITE_OS_OTHER=1] compile-time 1367 ** option) the application must supply a suitable implementation for 1368 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1369 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1370 ** must return [SQLITE_OK] on success and some other [error code] upon 1371 ** failure. 1372 */ 1373 SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void); 1374 SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void); 1375 SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void); 1376 SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void); 1377 1378 /* 1379 ** CAPI3REF: Configuring The SQLite Library 1380 ** 1381 ** The sqlite3_config() interface is used to make global configuration 1382 ** changes to SQLite in order to tune SQLite to the specific needs of 1383 ** the application. The default configuration is recommended for most 1384 ** applications and so this routine is usually not necessary. It is 1385 ** provided to support rare applications with unusual needs. 1386 ** 1387 ** <b>The sqlite3_config() interface is not threadsafe. The application 1388 ** must ensure that no other SQLite interfaces are invoked by other 1389 ** threads while sqlite3_config() is running.</b> 1390 ** 1391 ** The sqlite3_config() interface 1392 ** may only be invoked prior to library initialization using 1393 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1394 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1395 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1396 ** Note, however, that ^sqlite3_config() can be called as part of the 1397 ** implementation of an application-defined [sqlite3_os_init()]. 1398 ** 1399 ** The first argument to sqlite3_config() is an integer 1400 ** [configuration option] that determines 1401 ** what property of SQLite is to be configured. Subsequent arguments 1402 ** vary depending on the [configuration option] 1403 ** in the first argument. 1404 ** 1405 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1406 ** ^If the option is unknown or SQLite is unable to set the option 1407 ** then this routine returns a non-zero [error code]. 1408 */ 1409 SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...); 1410 1411 /* 1412 ** CAPI3REF: Configure database connections 1413 ** METHOD: sqlite3 1414 ** 1415 ** The sqlite3_db_config() interface is used to make configuration 1416 ** changes to a [database connection]. The interface is similar to 1417 ** [sqlite3_config()] except that the changes apply to a single 1418 ** [database connection] (specified in the first argument). 1419 ** 1420 ** The second argument to sqlite3_db_config(D,V,...) is the 1421 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1422 ** that indicates what aspect of the [database connection] is being configured. 1423 ** Subsequent arguments vary depending on the configuration verb. 1424 ** 1425 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1426 ** the call is considered successful. 1427 */ 1428 SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...); 1429 1430 /* 1431 ** CAPI3REF: Memory Allocation Routines 1432 ** 1433 ** An instance of this object defines the interface between SQLite 1434 ** and low-level memory allocation routines. 1435 ** 1436 ** This object is used in only one place in the SQLite interface. 1437 ** A pointer to an instance of this object is the argument to 1438 ** [sqlite3_config()] when the configuration option is 1439 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1440 ** By creating an instance of this object 1441 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1442 ** during configuration, an application can specify an alternative 1443 ** memory allocation subsystem for SQLite to use for all of its 1444 ** dynamic memory needs. 1445 ** 1446 ** Note that SQLite comes with several [built-in memory allocators] 1447 ** that are perfectly adequate for the overwhelming majority of applications 1448 ** and that this object is only useful to a tiny minority of applications 1449 ** with specialized memory allocation requirements. This object is 1450 ** also used during testing of SQLite in order to specify an alternative 1451 ** memory allocator that simulates memory out-of-memory conditions in 1452 ** order to verify that SQLite recovers gracefully from such 1453 ** conditions. 1454 ** 1455 ** The xMalloc, xRealloc, and xFree methods must work like the 1456 ** malloc(), realloc() and free() functions from the standard C library. 1457 ** ^SQLite guarantees that the second argument to 1458 ** xRealloc is always a value returned by a prior call to xRoundup. 1459 ** 1460 ** xSize should return the allocated size of a memory allocation 1461 ** previously obtained from xMalloc or xRealloc. The allocated size 1462 ** is always at least as big as the requested size but may be larger. 1463 ** 1464 ** The xRoundup method returns what would be the allocated size of 1465 ** a memory allocation given a particular requested size. Most memory 1466 ** allocators round up memory allocations at least to the next multiple 1467 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1468 ** Every memory allocation request coming in through [sqlite3_malloc()] 1469 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1470 ** that causes the corresponding memory allocation to fail. 1471 ** 1472 ** The xInit method initializes the memory allocator. For example, 1473 ** it might allocate any require mutexes or initialize internal data 1474 ** structures. The xShutdown method is invoked (indirectly) by 1475 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1476 ** by xInit. The pAppData pointer is used as the only parameter to 1477 ** xInit and xShutdown. 1478 ** 1479 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1480 ** the xInit method, so the xInit method need not be threadsafe. The 1481 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1482 ** not need to be threadsafe either. For all other methods, SQLite 1483 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1484 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1485 ** it is by default) and so the methods are automatically serialized. 1486 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1487 ** methods must be threadsafe or else make their own arrangements for 1488 ** serialization. 1489 ** 1490 ** SQLite will never invoke xInit() more than once without an intervening 1491 ** call to xShutdown(). 1492 */ 1493 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1494 struct sqlite3_mem_methods { 1495 void *(*xMalloc)(int); /* Memory allocation function */ 1496 void (*xFree)(void*); /* Free a prior allocation */ 1497 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1498 int (*xSize)(void*); /* Return the size of an allocation */ 1499 int (*xRoundup)(int); /* Round up request size to allocation size */ 1500 int (*xInit)(void*); /* Initialize the memory allocator */ 1501 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1502 void *pAppData; /* Argument to xInit() and xShutdown() */ 1503 }; 1504 1505 /* 1506 ** CAPI3REF: Configuration Options 1507 ** KEYWORDS: {configuration option} 1508 ** 1509 ** These constants are the available integer configuration options that 1510 ** can be passed as the first argument to the [sqlite3_config()] interface. 1511 ** 1512 ** New configuration options may be added in future releases of SQLite. 1513 ** Existing configuration options might be discontinued. Applications 1514 ** should check the return code from [sqlite3_config()] to make sure that 1515 ** the call worked. The [sqlite3_config()] interface will return a 1516 ** non-zero [error code] if a discontinued or unsupported configuration option 1517 ** is invoked. 1518 ** 1519 ** <dl> 1520 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1521 ** <dd>There are no arguments to this option. ^This option sets the 1522 ** [threading mode] to Single-thread. In other words, it disables 1523 ** all mutexing and puts SQLite into a mode where it can only be used 1524 ** by a single thread. ^If SQLite is compiled with 1525 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1526 ** it is not possible to change the [threading mode] from its default 1527 ** value of Single-thread and so [sqlite3_config()] will return 1528 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1529 ** configuration option.</dd> 1530 ** 1531 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1532 ** <dd>There are no arguments to this option. ^This option sets the 1533 ** [threading mode] to Multi-thread. In other words, it disables 1534 ** mutexing on [database connection] and [prepared statement] objects. 1535 ** The application is responsible for serializing access to 1536 ** [database connections] and [prepared statements]. But other mutexes 1537 ** are enabled so that SQLite will be safe to use in a multi-threaded 1538 ** environment as long as no two threads attempt to use the same 1539 ** [database connection] at the same time. ^If SQLite is compiled with 1540 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1541 ** it is not possible to set the Multi-thread [threading mode] and 1542 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1543 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1544 ** 1545 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1546 ** <dd>There are no arguments to this option. ^This option sets the 1547 ** [threading mode] to Serialized. In other words, this option enables 1548 ** all mutexes including the recursive 1549 ** mutexes on [database connection] and [prepared statement] objects. 1550 ** In this mode (which is the default when SQLite is compiled with 1551 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1552 ** to [database connections] and [prepared statements] so that the 1553 ** application is free to use the same [database connection] or the 1554 ** same [prepared statement] in different threads at the same time. 1555 ** ^If SQLite is compiled with 1556 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1557 ** it is not possible to set the Serialized [threading mode] and 1558 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1559 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1560 ** 1561 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1562 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1563 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1564 ** The argument specifies 1565 ** alternative low-level memory allocation routines to be used in place of 1566 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1567 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1568 ** before the [sqlite3_config()] call returns.</dd> 1569 ** 1570 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1571 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1572 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1573 ** The [sqlite3_mem_methods] 1574 ** structure is filled with the currently defined memory allocation routines.)^ 1575 ** This option can be used to overload the default memory allocation 1576 ** routines with a wrapper that simulations memory allocation failure or 1577 ** tracks memory usage, for example. </dd> 1578 ** 1579 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1580 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1581 ** interpreted as a boolean, which enables or disables the collection of 1582 ** memory allocation statistics. ^(When memory allocation statistics are 1583 ** disabled, the following SQLite interfaces become non-operational: 1584 ** <ul> 1585 ** <li> [sqlite3_memory_used()] 1586 ** <li> [sqlite3_memory_highwater()] 1587 ** <li> [sqlite3_soft_heap_limit64()] 1588 ** <li> [sqlite3_status64()] 1589 ** </ul>)^ 1590 ** ^Memory allocation statistics are enabled by default unless SQLite is 1591 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1592 ** allocation statistics are disabled by default. 1593 ** </dd> 1594 ** 1595 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1596 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1597 ** that SQLite can use for scratch memory. ^(There are three arguments 1598 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1599 ** aligned memory buffer from which the scratch allocations will be 1600 ** drawn, the size of each scratch allocation (sz), 1601 ** and the maximum number of scratch allocations (N).)^ 1602 ** The first argument must be a pointer to an 8-byte aligned buffer 1603 ** of at least sz*N bytes of memory. 1604 ** ^SQLite will not use more than one scratch buffers per thread. 1605 ** ^SQLite will never request a scratch buffer that is more than 6 1606 ** times the database page size. 1607 ** ^If SQLite needs needs additional 1608 ** scratch memory beyond what is provided by this configuration option, then 1609 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1610 ** ^When the application provides any amount of scratch memory using 1611 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1612 ** [sqlite3_malloc|heap allocations]. 1613 ** This can help [Robson proof|prevent memory allocation failures] due to heap 1614 ** fragmentation in low-memory embedded systems. 1615 ** </dd> 1616 ** 1617 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1618 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1619 ** that SQLite can use for the database page cache with the default page 1620 ** cache implementation. 1621 ** This configuration option is a no-op if an application-define page 1622 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1623 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1624 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1625 ** and the number of cache lines (N). 1626 ** The sz argument should be the size of the largest database page 1627 ** (a power of two between 512 and 65536) plus some extra bytes for each 1628 ** page header. ^The number of extra bytes needed by the page header 1629 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1630 ** ^It is harmless, apart from the wasted memory, 1631 ** for the sz parameter to be larger than necessary. The pMem 1632 ** argument must be either a NULL pointer or a pointer to an 8-byte 1633 ** aligned block of memory of at least sz*N bytes, otherwise 1634 ** subsequent behavior is undefined. 1635 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1636 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1637 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1638 ** is exhausted. 1639 ** ^If pMem is NULL and N is non-zero, then each database connection 1640 ** does an initial bulk allocation for page cache memory 1641 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1642 ** of -1024*N bytes if N is negative, . ^If additional 1643 ** page cache memory is needed beyond what is provided by the initial 1644 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1645 ** additional cache line. </dd> 1646 ** 1647 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1648 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1649 ** that SQLite will use for all of its dynamic memory allocation needs 1650 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1651 ** [SQLITE_CONFIG_PAGECACHE]. 1652 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1653 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1654 ** [SQLITE_ERROR] if invoked otherwise. 1655 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1656 ** An 8-byte aligned pointer to the memory, 1657 ** the number of bytes in the memory buffer, and the minimum allocation size. 1658 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1659 ** to using its default memory allocator (the system malloc() implementation), 1660 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1661 ** memory pointer is not NULL then the alternative memory 1662 ** allocator is engaged to handle all of SQLites memory allocation needs. 1663 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1664 ** boundary or subsequent behavior of SQLite will be undefined. 1665 ** The minimum allocation size is capped at 2**12. Reasonable values 1666 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1667 ** 1668 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1669 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1670 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1671 ** The argument specifies alternative low-level mutex routines to be used 1672 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1673 ** the content of the [sqlite3_mutex_methods] structure before the call to 1674 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1675 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1676 ** the entire mutexing subsystem is omitted from the build and hence calls to 1677 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1678 ** return [SQLITE_ERROR].</dd> 1679 ** 1680 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1681 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1682 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1683 ** [sqlite3_mutex_methods] 1684 ** structure is filled with the currently defined mutex routines.)^ 1685 ** This option can be used to overload the default mutex allocation 1686 ** routines with a wrapper used to track mutex usage for performance 1687 ** profiling or testing, for example. ^If SQLite is compiled with 1688 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1689 ** the entire mutexing subsystem is omitted from the build and hence calls to 1690 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1691 ** return [SQLITE_ERROR].</dd> 1692 ** 1693 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1694 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1695 ** the default size of lookaside memory on each [database connection]. 1696 ** The first argument is the 1697 ** size of each lookaside buffer slot and the second is the number of 1698 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1699 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1700 ** option to [sqlite3_db_config()] can be used to change the lookaside 1701 ** configuration on individual connections.)^ </dd> 1702 ** 1703 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1704 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1705 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1706 ** the interface to a custom page cache implementation.)^ 1707 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1708 ** 1709 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1710 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1711 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1712 ** the current page cache implementation into that object.)^ </dd> 1713 ** 1714 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1715 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1716 ** global [error log]. 1717 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1718 ** function with a call signature of void(*)(void*,int,const char*), 1719 ** and a pointer to void. ^If the function pointer is not NULL, it is 1720 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1721 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1722 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1723 ** passed through as the first parameter to the application-defined logger 1724 ** function whenever that function is invoked. ^The second parameter to 1725 ** the logger function is a copy of the first parameter to the corresponding 1726 ** [sqlite3_log()] call and is intended to be a [result code] or an 1727 ** [extended result code]. ^The third parameter passed to the logger is 1728 ** log message after formatting via [sqlite3_snprintf()]. 1729 ** The SQLite logging interface is not reentrant; the logger function 1730 ** supplied by the application must not invoke any SQLite interface. 1731 ** In a multi-threaded application, the application-defined logger 1732 ** function must be threadsafe. </dd> 1733 ** 1734 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1735 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1736 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1737 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1738 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1739 ** [sqlite3_open16()] or 1740 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1741 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1742 ** connection is opened. ^If it is globally disabled, filenames are 1743 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1744 ** database connection is opened. ^(By default, URI handling is globally 1745 ** disabled. The default value may be changed by compiling with the 1746 ** [SQLITE_USE_URI] symbol defined.)^ 1747 ** 1748 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1749 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1750 ** argument which is interpreted as a boolean in order to enable or disable 1751 ** the use of covering indices for full table scans in the query optimizer. 1752 ** ^The default setting is determined 1753 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1754 ** if that compile-time option is omitted. 1755 ** The ability to disable the use of covering indices for full table scans 1756 ** is because some incorrectly coded legacy applications might malfunction 1757 ** when the optimization is enabled. Providing the ability to 1758 ** disable the optimization allows the older, buggy application code to work 1759 ** without change even with newer versions of SQLite. 1760 ** 1761 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1762 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1763 ** <dd> These options are obsolete and should not be used by new code. 1764 ** They are retained for backwards compatibility but are now no-ops. 1765 ** </dd> 1766 ** 1767 ** [[SQLITE_CONFIG_SQLLOG]] 1768 ** <dt>SQLITE_CONFIG_SQLLOG 1769 ** <dd>This option is only available if sqlite is compiled with the 1770 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1771 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1772 ** The second should be of type (void*). The callback is invoked by the library 1773 ** in three separate circumstances, identified by the value passed as the 1774 ** fourth parameter. If the fourth parameter is 0, then the database connection 1775 ** passed as the second argument has just been opened. The third argument 1776 ** points to a buffer containing the name of the main database file. If the 1777 ** fourth parameter is 1, then the SQL statement that the third parameter 1778 ** points to has just been executed. Or, if the fourth parameter is 2, then 1779 ** the connection being passed as the second parameter is being closed. The 1780 ** third parameter is passed NULL In this case. An example of using this 1781 ** configuration option can be seen in the "test_sqllog.c" source file in 1782 ** the canonical SQLite source tree.</dd> 1783 ** 1784 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1785 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1786 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1787 ** that are the default mmap size limit (the default setting for 1788 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1789 ** ^The default setting can be overridden by each database connection using 1790 ** either the [PRAGMA mmap_size] command, or by using the 1791 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1792 ** will be silently truncated if necessary so that it does not exceed the 1793 ** compile-time maximum mmap size set by the 1794 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1795 ** ^If either argument to this option is negative, then that argument is 1796 ** changed to its compile-time default. 1797 ** 1798 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1799 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1800 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1801 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1802 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1803 ** that specifies the maximum size of the created heap. 1804 ** 1805 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1806 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1807 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1808 ** is a pointer to an integer and writes into that integer the number of extra 1809 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1810 ** The amount of extra space required can change depending on the compiler, 1811 ** target platform, and SQLite version. 1812 ** 1813 ** [[SQLITE_CONFIG_PMASZ]] 1814 ** <dt>SQLITE_CONFIG_PMASZ 1815 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1816 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1817 ** sorter to that integer. The default minimum PMA Size is set by the 1818 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1819 ** to help with sort operations when multithreaded sorting 1820 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1821 ** to be sorted exceeds the page size times the minimum of the 1822 ** [PRAGMA cache_size] setting and this value. 1823 ** 1824 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1825 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1826 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1827 ** becomes the [statement journal] spill-to-disk threshold. 1828 ** [Statement journals] are held in memory until their size (in bytes) 1829 ** exceeds this threshold, at which point they are written to disk. 1830 ** Or if the threshold is -1, statement journals are always held 1831 ** exclusively in memory. 1832 ** Since many statement journals never become large, setting the spill 1833 ** threshold to a value such as 64KiB can greatly reduce the amount of 1834 ** I/O required to support statement rollback. 1835 ** The default value for this setting is controlled by the 1836 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1837 ** </dl> 1838 */ 1839 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1840 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1841 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1842 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1843 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1844 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1845 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1846 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1847 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1848 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1849 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1850 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1851 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1852 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1853 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1854 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1855 #define SQLITE_CONFIG_URI 17 /* int */ 1856 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1857 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1858 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1859 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1860 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1861 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1862 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1863 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1864 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1865 1866 /* 1867 ** CAPI3REF: Database Connection Configuration Options 1868 ** 1869 ** These constants are the available integer configuration options that 1870 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1871 ** 1872 ** New configuration options may be added in future releases of SQLite. 1873 ** Existing configuration options might be discontinued. Applications 1874 ** should check the return code from [sqlite3_db_config()] to make sure that 1875 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1876 ** non-zero [error code] if a discontinued or unsupported configuration option 1877 ** is invoked. 1878 ** 1879 ** <dl> 1880 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1881 ** <dd> ^This option takes three additional arguments that determine the 1882 ** [lookaside memory allocator] configuration for the [database connection]. 1883 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1884 ** pointer to a memory buffer to use for lookaside memory. 1885 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1886 ** may be NULL in which case SQLite will allocate the 1887 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1888 ** size of each lookaside buffer slot. ^The third argument is the number of 1889 ** slots. The size of the buffer in the first argument must be greater than 1890 ** or equal to the product of the second and third arguments. The buffer 1891 ** must be aligned to an 8-byte boundary. ^If the second argument to 1892 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1893 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1894 ** configuration for a database connection can only be changed when that 1895 ** connection is not currently using lookaside memory, or in other words 1896 ** when the "current value" returned by 1897 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1898 ** Any attempt to change the lookaside memory configuration when lookaside 1899 ** memory is in use leaves the configuration unchanged and returns 1900 ** [SQLITE_BUSY].)^</dd> 1901 ** 1902 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1903 ** <dd> ^This option is used to enable or disable the enforcement of 1904 ** [foreign key constraints]. There should be two additional arguments. 1905 ** The first argument is an integer which is 0 to disable FK enforcement, 1906 ** positive to enable FK enforcement or negative to leave FK enforcement 1907 ** unchanged. The second parameter is a pointer to an integer into which 1908 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1909 ** following this call. The second parameter may be a NULL pointer, in 1910 ** which case the FK enforcement setting is not reported back. </dd> 1911 ** 1912 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1913 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1914 ** There should be two additional arguments. 1915 ** The first argument is an integer which is 0 to disable triggers, 1916 ** positive to enable triggers or negative to leave the setting unchanged. 1917 ** The second parameter is a pointer to an integer into which 1918 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1919 ** following this call. The second parameter may be a NULL pointer, in 1920 ** which case the trigger setting is not reported back. </dd> 1921 ** 1922 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1923 ** <dd> ^This option is used to enable or disable the two-argument 1924 ** version of the [fts3_tokenizer()] function which is part of the 1925 ** [FTS3] full-text search engine extension. 1926 ** There should be two additional arguments. 1927 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1928 ** positive to enable fts3_tokenizer() or negative to leave the setting 1929 ** unchanged. 1930 ** The second parameter is a pointer to an integer into which 1931 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1932 ** following this call. The second parameter may be a NULL pointer, in 1933 ** which case the new setting is not reported back. </dd> 1934 ** 1935 ** </dl> 1936 */ 1937 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1938 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1939 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1940 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 1941 1942 1943 /* 1944 ** CAPI3REF: Enable Or Disable Extended Result Codes 1945 ** METHOD: sqlite3 1946 ** 1947 ** ^The sqlite3_extended_result_codes() routine enables or disables the 1948 ** [extended result codes] feature of SQLite. ^The extended result 1949 ** codes are disabled by default for historical compatibility. 1950 */ 1951 SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff); 1952 1953 /* 1954 ** CAPI3REF: Last Insert Rowid 1955 ** METHOD: sqlite3 1956 ** 1957 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1958 ** has a unique 64-bit signed 1959 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1960 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1961 ** names are not also used by explicitly declared columns. ^If 1962 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 1963 ** is another alias for the rowid. 1964 ** 1965 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1966 ** most recent successful [INSERT] into a rowid table or [virtual table] 1967 ** on database connection D. 1968 ** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1969 ** ^If no successful [INSERT]s into rowid tables 1970 ** have ever occurred on the database connection D, 1971 ** then sqlite3_last_insert_rowid(D) returns zero. 1972 ** 1973 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1974 ** method, then this routine will return the [rowid] of the inserted 1975 ** row as long as the trigger or virtual table method is running. 1976 ** But once the trigger or virtual table method ends, the value returned 1977 ** by this routine reverts to what it was before the trigger or virtual 1978 ** table method began.)^ 1979 ** 1980 ** ^An [INSERT] that fails due to a constraint violation is not a 1981 ** successful [INSERT] and does not change the value returned by this 1982 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1983 ** and INSERT OR ABORT make no changes to the return value of this 1984 ** routine when their insertion fails. ^(When INSERT OR REPLACE 1985 ** encounters a constraint violation, it does not fail. The 1986 ** INSERT continues to completion after deleting rows that caused 1987 ** the constraint problem so INSERT OR REPLACE will always change 1988 ** the return value of this interface.)^ 1989 ** 1990 ** ^For the purposes of this routine, an [INSERT] is considered to 1991 ** be successful even if it is subsequently rolled back. 1992 ** 1993 ** This function is accessible to SQL statements via the 1994 ** [last_insert_rowid() SQL function]. 1995 ** 1996 ** If a separate thread performs a new [INSERT] on the same 1997 ** database connection while the [sqlite3_last_insert_rowid()] 1998 ** function is running and thus changes the last insert [rowid], 1999 ** then the value returned by [sqlite3_last_insert_rowid()] is 2000 ** unpredictable and might not equal either the old or the new 2001 ** last insert [rowid]. 2002 */ 2003 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*); 2004 2005 /* 2006 ** CAPI3REF: Count The Number Of Rows Modified 2007 ** METHOD: sqlite3 2008 ** 2009 ** ^This function returns the number of rows modified, inserted or 2010 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2011 ** statement on the database connection specified by the only parameter. 2012 ** ^Executing any other type of SQL statement does not modify the value 2013 ** returned by this function. 2014 ** 2015 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2016 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2017 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2018 ** 2019 ** Changes to a view that are intercepted by 2020 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2021 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2022 ** DELETE statement run on a view is always zero. Only changes made to real 2023 ** tables are counted. 2024 ** 2025 ** Things are more complicated if the sqlite3_changes() function is 2026 ** executed while a trigger program is running. This may happen if the 2027 ** program uses the [changes() SQL function], or if some other callback 2028 ** function invokes sqlite3_changes() directly. Essentially: 2029 ** 2030 ** <ul> 2031 ** <li> ^(Before entering a trigger program the value returned by 2032 ** sqlite3_changes() function is saved. After the trigger program 2033 ** has finished, the original value is restored.)^ 2034 ** 2035 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2036 ** statement sets the value returned by sqlite3_changes() 2037 ** upon completion as normal. Of course, this value will not include 2038 ** any changes performed by sub-triggers, as the sqlite3_changes() 2039 ** value will be saved and restored after each sub-trigger has run.)^ 2040 ** </ul> 2041 ** 2042 ** ^This means that if the changes() SQL function (or similar) is used 2043 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2044 ** returns the value as set when the calling statement began executing. 2045 ** ^If it is used by the second or subsequent such statement within a trigger 2046 ** program, the value returned reflects the number of rows modified by the 2047 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2048 ** 2049 ** See also the [sqlite3_total_changes()] interface, the 2050 ** [count_changes pragma], and the [changes() SQL function]. 2051 ** 2052 ** If a separate thread makes changes on the same database connection 2053 ** while [sqlite3_changes()] is running then the value returned 2054 ** is unpredictable and not meaningful. 2055 */ 2056 SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*); 2057 2058 /* 2059 ** CAPI3REF: Total Number Of Rows Modified 2060 ** METHOD: sqlite3 2061 ** 2062 ** ^This function returns the total number of rows inserted, modified or 2063 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2064 ** since the database connection was opened, including those executed as 2065 ** part of trigger programs. ^Executing any other type of SQL statement 2066 ** does not affect the value returned by sqlite3_total_changes(). 2067 ** 2068 ** ^Changes made as part of [foreign key actions] are included in the 2069 ** count, but those made as part of REPLACE constraint resolution are 2070 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2071 ** are not counted. 2072 ** 2073 ** See also the [sqlite3_changes()] interface, the 2074 ** [count_changes pragma], and the [total_changes() SQL function]. 2075 ** 2076 ** If a separate thread makes changes on the same database connection 2077 ** while [sqlite3_total_changes()] is running then the value 2078 ** returned is unpredictable and not meaningful. 2079 */ 2080 SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*); 2081 2082 /* 2083 ** CAPI3REF: Interrupt A Long-Running Query 2084 ** METHOD: sqlite3 2085 ** 2086 ** ^This function causes any pending database operation to abort and 2087 ** return at its earliest opportunity. This routine is typically 2088 ** called in response to a user action such as pressing "Cancel" 2089 ** or Ctrl-C where the user wants a long query operation to halt 2090 ** immediately. 2091 ** 2092 ** ^It is safe to call this routine from a thread different from the 2093 ** thread that is currently running the database operation. But it 2094 ** is not safe to call this routine with a [database connection] that 2095 ** is closed or might close before sqlite3_interrupt() returns. 2096 ** 2097 ** ^If an SQL operation is very nearly finished at the time when 2098 ** sqlite3_interrupt() is called, then it might not have an opportunity 2099 ** to be interrupted and might continue to completion. 2100 ** 2101 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2102 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2103 ** that is inside an explicit transaction, then the entire transaction 2104 ** will be rolled back automatically. 2105 ** 2106 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2107 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2108 ** that are started after the sqlite3_interrupt() call and before the 2109 ** running statements reaches zero are interrupted as if they had been 2110 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2111 ** that are started after the running statement count reaches zero are 2112 ** not effected by the sqlite3_interrupt(). 2113 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2114 ** SQL statements is a no-op and has no effect on SQL statements 2115 ** that are started after the sqlite3_interrupt() call returns. 2116 ** 2117 ** If the database connection closes while [sqlite3_interrupt()] 2118 ** is running then bad things will likely happen. 2119 */ 2120 SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*); 2121 2122 /* 2123 ** CAPI3REF: Determine If An SQL Statement Is Complete 2124 ** 2125 ** These routines are useful during command-line input to determine if the 2126 ** currently entered text seems to form a complete SQL statement or 2127 ** if additional input is needed before sending the text into 2128 ** SQLite for parsing. ^These routines return 1 if the input string 2129 ** appears to be a complete SQL statement. ^A statement is judged to be 2130 ** complete if it ends with a semicolon token and is not a prefix of a 2131 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2132 ** string literals or quoted identifier names or comments are not 2133 ** independent tokens (they are part of the token in which they are 2134 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2135 ** and comments that follow the final semicolon are ignored. 2136 ** 2137 ** ^These routines return 0 if the statement is incomplete. ^If a 2138 ** memory allocation fails, then SQLITE_NOMEM is returned. 2139 ** 2140 ** ^These routines do not parse the SQL statements thus 2141 ** will not detect syntactically incorrect SQL. 2142 ** 2143 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2144 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2145 ** automatically by sqlite3_complete16(). If that initialization fails, 2146 ** then the return value from sqlite3_complete16() will be non-zero 2147 ** regardless of whether or not the input SQL is complete.)^ 2148 ** 2149 ** The input to [sqlite3_complete()] must be a zero-terminated 2150 ** UTF-8 string. 2151 ** 2152 ** The input to [sqlite3_complete16()] must be a zero-terminated 2153 ** UTF-16 string in native byte order. 2154 */ 2155 SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql); 2156 SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql); 2157 2158 /* 2159 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2160 ** KEYWORDS: {busy-handler callback} {busy handler} 2161 ** METHOD: sqlite3 2162 ** 2163 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2164 ** that might be invoked with argument P whenever 2165 ** an attempt is made to access a database table associated with 2166 ** [database connection] D when another thread 2167 ** or process has the table locked. 2168 ** The sqlite3_busy_handler() interface is used to implement 2169 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2170 ** 2171 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2172 ** is returned immediately upon encountering the lock. ^If the busy callback 2173 ** is not NULL, then the callback might be invoked with two arguments. 2174 ** 2175 ** ^The first argument to the busy handler is a copy of the void* pointer which 2176 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2177 ** the busy handler callback is the number of times that the busy handler has 2178 ** been invoked previously for the same locking event. ^If the 2179 ** busy callback returns 0, then no additional attempts are made to 2180 ** access the database and [SQLITE_BUSY] is returned 2181 ** to the application. 2182 ** ^If the callback returns non-zero, then another attempt 2183 ** is made to access the database and the cycle repeats. 2184 ** 2185 ** The presence of a busy handler does not guarantee that it will be invoked 2186 ** when there is lock contention. ^If SQLite determines that invoking the busy 2187 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2188 ** to the application instead of invoking the 2189 ** busy handler. 2190 ** Consider a scenario where one process is holding a read lock that 2191 ** it is trying to promote to a reserved lock and 2192 ** a second process is holding a reserved lock that it is trying 2193 ** to promote to an exclusive lock. The first process cannot proceed 2194 ** because it is blocked by the second and the second process cannot 2195 ** proceed because it is blocked by the first. If both processes 2196 ** invoke the busy handlers, neither will make any progress. Therefore, 2197 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2198 ** will induce the first process to release its read lock and allow 2199 ** the second process to proceed. 2200 ** 2201 ** ^The default busy callback is NULL. 2202 ** 2203 ** ^(There can only be a single busy handler defined for each 2204 ** [database connection]. Setting a new busy handler clears any 2205 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2206 ** or evaluating [PRAGMA busy_timeout=N] will change the 2207 ** busy handler and thus clear any previously set busy handler. 2208 ** 2209 ** The busy callback should not take any actions which modify the 2210 ** database connection that invoked the busy handler. In other words, 2211 ** the busy handler is not reentrant. Any such actions 2212 ** result in undefined behavior. 2213 ** 2214 ** A busy handler must not close the database connection 2215 ** or [prepared statement] that invoked the busy handler. 2216 */ 2217 SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2218 2219 /* 2220 ** CAPI3REF: Set A Busy Timeout 2221 ** METHOD: sqlite3 2222 ** 2223 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2224 ** for a specified amount of time when a table is locked. ^The handler 2225 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2226 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2227 ** the handler returns 0 which causes [sqlite3_step()] to return 2228 ** [SQLITE_BUSY]. 2229 ** 2230 ** ^Calling this routine with an argument less than or equal to zero 2231 ** turns off all busy handlers. 2232 ** 2233 ** ^(There can only be a single busy handler for a particular 2234 ** [database connection] at any given moment. If another busy handler 2235 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2236 ** this routine, that other busy handler is cleared.)^ 2237 ** 2238 ** See also: [PRAGMA busy_timeout] 2239 */ 2240 SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms); 2241 2242 /* 2243 ** CAPI3REF: Convenience Routines For Running Queries 2244 ** METHOD: sqlite3 2245 ** 2246 ** This is a legacy interface that is preserved for backwards compatibility. 2247 ** Use of this interface is not recommended. 2248 ** 2249 ** Definition: A <b>result table</b> is memory data structure created by the 2250 ** [sqlite3_get_table()] interface. A result table records the 2251 ** complete query results from one or more queries. 2252 ** 2253 ** The table conceptually has a number of rows and columns. But 2254 ** these numbers are not part of the result table itself. These 2255 ** numbers are obtained separately. Let N be the number of rows 2256 ** and M be the number of columns. 2257 ** 2258 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2259 ** There are (N+1)*M elements in the array. The first M pointers point 2260 ** to zero-terminated strings that contain the names of the columns. 2261 ** The remaining entries all point to query results. NULL values result 2262 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2263 ** string representation as returned by [sqlite3_column_text()]. 2264 ** 2265 ** A result table might consist of one or more memory allocations. 2266 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2267 ** A result table should be deallocated using [sqlite3_free_table()]. 2268 ** 2269 ** ^(As an example of the result table format, suppose a query result 2270 ** is as follows: 2271 ** 2272 ** <blockquote><pre> 2273 ** Name | Age 2274 ** ----------------------- 2275 ** Alice | 43 2276 ** Bob | 28 2277 ** Cindy | 21 2278 ** </pre></blockquote> 2279 ** 2280 ** There are two column (M==2) and three rows (N==3). Thus the 2281 ** result table has 8 entries. Suppose the result table is stored 2282 ** in an array names azResult. Then azResult holds this content: 2283 ** 2284 ** <blockquote><pre> 2285 ** azResult[0] = "Name"; 2286 ** azResult[1] = "Age"; 2287 ** azResult[2] = "Alice"; 2288 ** azResult[3] = "43"; 2289 ** azResult[4] = "Bob"; 2290 ** azResult[5] = "28"; 2291 ** azResult[6] = "Cindy"; 2292 ** azResult[7] = "21"; 2293 ** </pre></blockquote>)^ 2294 ** 2295 ** ^The sqlite3_get_table() function evaluates one or more 2296 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2297 ** string of its 2nd parameter and returns a result table to the 2298 ** pointer given in its 3rd parameter. 2299 ** 2300 ** After the application has finished with the result from sqlite3_get_table(), 2301 ** it must pass the result table pointer to sqlite3_free_table() in order to 2302 ** release the memory that was malloced. Because of the way the 2303 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2304 ** function must not try to call [sqlite3_free()] directly. Only 2305 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2306 ** 2307 ** The sqlite3_get_table() interface is implemented as a wrapper around 2308 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2309 ** to any internal data structures of SQLite. It uses only the public 2310 ** interface defined here. As a consequence, errors that occur in the 2311 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2312 ** reflected in subsequent calls to [sqlite3_errcode()] or 2313 ** [sqlite3_errmsg()]. 2314 */ 2315 SQLITE_API int SQLITE_STDCALL sqlite3_get_table( 2316 sqlite3 *db, /* An open database */ 2317 const char *zSql, /* SQL to be evaluated */ 2318 char ***pazResult, /* Results of the query */ 2319 int *pnRow, /* Number of result rows written here */ 2320 int *pnColumn, /* Number of result columns written here */ 2321 char **pzErrmsg /* Error msg written here */ 2322 ); 2323 SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result); 2324 2325 /* 2326 ** CAPI3REF: Formatted String Printing Functions 2327 ** 2328 ** These routines are work-alikes of the "printf()" family of functions 2329 ** from the standard C library. 2330 ** These routines understand most of the common K&R formatting options, 2331 ** plus some additional non-standard formats, detailed below. 2332 ** Note that some of the more obscure formatting options from recent 2333 ** C-library standards are omitted from this implementation. 2334 ** 2335 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2336 ** results into memory obtained from [sqlite3_malloc()]. 2337 ** The strings returned by these two routines should be 2338 ** released by [sqlite3_free()]. ^Both routines return a 2339 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2340 ** memory to hold the resulting string. 2341 ** 2342 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2343 ** the standard C library. The result is written into the 2344 ** buffer supplied as the second parameter whose size is given by 2345 ** the first parameter. Note that the order of the 2346 ** first two parameters is reversed from snprintf().)^ This is an 2347 ** historical accident that cannot be fixed without breaking 2348 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2349 ** returns a pointer to its buffer instead of the number of 2350 ** characters actually written into the buffer.)^ We admit that 2351 ** the number of characters written would be a more useful return 2352 ** value but we cannot change the implementation of sqlite3_snprintf() 2353 ** now without breaking compatibility. 2354 ** 2355 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2356 ** guarantees that the buffer is always zero-terminated. ^The first 2357 ** parameter "n" is the total size of the buffer, including space for 2358 ** the zero terminator. So the longest string that can be completely 2359 ** written will be n-1 characters. 2360 ** 2361 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2362 ** 2363 ** These routines all implement some additional formatting 2364 ** options that are useful for constructing SQL statements. 2365 ** All of the usual printf() formatting options apply. In addition, there 2366 ** is are "%q", "%Q", "%w" and "%z" options. 2367 ** 2368 ** ^(The %q option works like %s in that it substitutes a nul-terminated 2369 ** string from the argument list. But %q also doubles every '\'' character. 2370 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2371 ** character it escapes that character and allows it to be inserted into 2372 ** the string. 2373 ** 2374 ** For example, assume the string variable zText contains text as follows: 2375 ** 2376 ** <blockquote><pre> 2377 ** char *zText = "It's a happy day!"; 2378 ** </pre></blockquote> 2379 ** 2380 ** One can use this text in an SQL statement as follows: 2381 ** 2382 ** <blockquote><pre> 2383 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2384 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2385 ** sqlite3_free(zSQL); 2386 ** </pre></blockquote> 2387 ** 2388 ** Because the %q format string is used, the '\'' character in zText 2389 ** is escaped and the SQL generated is as follows: 2390 ** 2391 ** <blockquote><pre> 2392 ** INSERT INTO table1 VALUES('It''s a happy day!') 2393 ** </pre></blockquote> 2394 ** 2395 ** This is correct. Had we used %s instead of %q, the generated SQL 2396 ** would have looked like this: 2397 ** 2398 ** <blockquote><pre> 2399 ** INSERT INTO table1 VALUES('It's a happy day!'); 2400 ** </pre></blockquote> 2401 ** 2402 ** This second example is an SQL syntax error. As a general rule you should 2403 ** always use %q instead of %s when inserting text into a string literal. 2404 ** 2405 ** ^(The %Q option works like %q except it also adds single quotes around 2406 ** the outside of the total string. Additionally, if the parameter in the 2407 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2408 ** single quotes).)^ So, for example, one could say: 2409 ** 2410 ** <blockquote><pre> 2411 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2412 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2413 ** sqlite3_free(zSQL); 2414 ** </pre></blockquote> 2415 ** 2416 ** The code above will render a correct SQL statement in the zSQL 2417 ** variable even if the zText variable is a NULL pointer. 2418 ** 2419 ** ^(The "%w" formatting option is like "%q" except that it expects to 2420 ** be contained within double-quotes instead of single quotes, and it 2421 ** escapes the double-quote character instead of the single-quote 2422 ** character.)^ The "%w" formatting option is intended for safely inserting 2423 ** table and column names into a constructed SQL statement. 2424 ** 2425 ** ^(The "%z" formatting option works like "%s" but with the 2426 ** addition that after the string has been read and copied into 2427 ** the result, [sqlite3_free()] is called on the input string.)^ 2428 */ 2429 SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...); 2430 SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list); 2431 SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...); 2432 SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list); 2433 2434 /* 2435 ** CAPI3REF: Memory Allocation Subsystem 2436 ** 2437 ** The SQLite core uses these three routines for all of its own 2438 ** internal memory allocation needs. "Core" in the previous sentence 2439 ** does not include operating-system specific VFS implementation. The 2440 ** Windows VFS uses native malloc() and free() for some operations. 2441 ** 2442 ** ^The sqlite3_malloc() routine returns a pointer to a block 2443 ** of memory at least N bytes in length, where N is the parameter. 2444 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2445 ** memory, it returns a NULL pointer. ^If the parameter N to 2446 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2447 ** a NULL pointer. 2448 ** 2449 ** ^The sqlite3_malloc64(N) routine works just like 2450 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2451 ** of a signed 32-bit integer. 2452 ** 2453 ** ^Calling sqlite3_free() with a pointer previously returned 2454 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2455 ** that it might be reused. ^The sqlite3_free() routine is 2456 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2457 ** to sqlite3_free() is harmless. After being freed, memory 2458 ** should neither be read nor written. Even reading previously freed 2459 ** memory might result in a segmentation fault or other severe error. 2460 ** Memory corruption, a segmentation fault, or other severe error 2461 ** might result if sqlite3_free() is called with a non-NULL pointer that 2462 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2463 ** 2464 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2465 ** prior memory allocation X to be at least N bytes. 2466 ** ^If the X parameter to sqlite3_realloc(X,N) 2467 ** is a NULL pointer then its behavior is identical to calling 2468 ** sqlite3_malloc(N). 2469 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2470 ** negative then the behavior is exactly the same as calling 2471 ** sqlite3_free(X). 2472 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2473 ** of at least N bytes in size or NULL if insufficient memory is available. 2474 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2475 ** of the prior allocation are copied into the beginning of buffer returned 2476 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2477 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2478 ** prior allocation is not freed. 2479 ** 2480 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2481 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2482 ** of a 32-bit signed integer. 2483 ** 2484 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2485 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2486 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2487 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2488 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2489 ** sqlite3_msize(X) returns zero. If X points to something that is not 2490 ** the beginning of memory allocation, or if it points to a formerly 2491 ** valid memory allocation that has now been freed, then the behavior 2492 ** of sqlite3_msize(X) is undefined and possibly harmful. 2493 ** 2494 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2495 ** sqlite3_malloc64(), and sqlite3_realloc64() 2496 ** is always aligned to at least an 8 byte boundary, or to a 2497 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2498 ** option is used. 2499 ** 2500 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2501 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2502 ** implementation of these routines to be omitted. That capability 2503 ** is no longer provided. Only built-in memory allocators can be used. 2504 ** 2505 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2506 ** the system malloc() and free() directly when converting 2507 ** filenames between the UTF-8 encoding used by SQLite 2508 ** and whatever filename encoding is used by the particular Windows 2509 ** installation. Memory allocation errors were detected, but 2510 ** they were reported back as [SQLITE_CANTOPEN] or 2511 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2512 ** 2513 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2514 ** must be either NULL or else pointers obtained from a prior 2515 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2516 ** not yet been released. 2517 ** 2518 ** The application must not read or write any part of 2519 ** a block of memory after it has been released using 2520 ** [sqlite3_free()] or [sqlite3_realloc()]. 2521 */ 2522 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int); 2523 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64); 2524 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int); 2525 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64); 2526 SQLITE_API void SQLITE_STDCALL sqlite3_free(void*); 2527 SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*); 2528 2529 /* 2530 ** CAPI3REF: Memory Allocator Statistics 2531 ** 2532 ** SQLite provides these two interfaces for reporting on the status 2533 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2534 ** routines, which form the built-in memory allocation subsystem. 2535 ** 2536 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2537 ** of memory currently outstanding (malloced but not freed). 2538 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2539 ** value of [sqlite3_memory_used()] since the high-water mark 2540 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2541 ** [sqlite3_memory_highwater()] include any overhead 2542 ** added by SQLite in its implementation of [sqlite3_malloc()], 2543 ** but not overhead added by the any underlying system library 2544 ** routines that [sqlite3_malloc()] may call. 2545 ** 2546 ** ^The memory high-water mark is reset to the current value of 2547 ** [sqlite3_memory_used()] if and only if the parameter to 2548 ** [sqlite3_memory_highwater()] is true. ^The value returned 2549 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2550 ** prior to the reset. 2551 */ 2552 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void); 2553 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag); 2554 2555 /* 2556 ** CAPI3REF: Pseudo-Random Number Generator 2557 ** 2558 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2559 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2560 ** already uses the largest possible [ROWID]. The PRNG is also used for 2561 ** the build-in random() and randomblob() SQL functions. This interface allows 2562 ** applications to access the same PRNG for other purposes. 2563 ** 2564 ** ^A call to this routine stores N bytes of randomness into buffer P. 2565 ** ^The P parameter can be a NULL pointer. 2566 ** 2567 ** ^If this routine has not been previously called or if the previous 2568 ** call had N less than one or a NULL pointer for P, then the PRNG is 2569 ** seeded using randomness obtained from the xRandomness method of 2570 ** the default [sqlite3_vfs] object. 2571 ** ^If the previous call to this routine had an N of 1 or more and a 2572 ** non-NULL P then the pseudo-randomness is generated 2573 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2574 ** method. 2575 */ 2576 SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P); 2577 2578 /* 2579 ** CAPI3REF: Compile-Time Authorization Callbacks 2580 ** METHOD: sqlite3 2581 ** 2582 ** ^This routine registers an authorizer callback with a particular 2583 ** [database connection], supplied in the first argument. 2584 ** ^The authorizer callback is invoked as SQL statements are being compiled 2585 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2586 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2587 ** points during the compilation process, as logic is being created 2588 ** to perform various actions, the authorizer callback is invoked to 2589 ** see if those actions are allowed. ^The authorizer callback should 2590 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2591 ** specific action but allow the SQL statement to continue to be 2592 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2593 ** rejected with an error. ^If the authorizer callback returns 2594 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2595 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2596 ** the authorizer will fail with an error message. 2597 ** 2598 ** When the callback returns [SQLITE_OK], that means the operation 2599 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2600 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2601 ** authorizer will fail with an error message explaining that 2602 ** access is denied. 2603 ** 2604 ** ^The first parameter to the authorizer callback is a copy of the third 2605 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2606 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2607 ** the particular action to be authorized. ^The third through sixth parameters 2608 ** to the callback are zero-terminated strings that contain additional 2609 ** details about the action to be authorized. 2610 ** 2611 ** ^If the action code is [SQLITE_READ] 2612 ** and the callback returns [SQLITE_IGNORE] then the 2613 ** [prepared statement] statement is constructed to substitute 2614 ** a NULL value in place of the table column that would have 2615 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2616 ** return can be used to deny an untrusted user access to individual 2617 ** columns of a table. 2618 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2619 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2620 ** [truncate optimization] is disabled and all rows are deleted individually. 2621 ** 2622 ** An authorizer is used when [sqlite3_prepare | preparing] 2623 ** SQL statements from an untrusted source, to ensure that the SQL statements 2624 ** do not try to access data they are not allowed to see, or that they do not 2625 ** try to execute malicious statements that damage the database. For 2626 ** example, an application may allow a user to enter arbitrary 2627 ** SQL queries for evaluation by a database. But the application does 2628 ** not want the user to be able to make arbitrary changes to the 2629 ** database. An authorizer could then be put in place while the 2630 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2631 ** disallows everything except [SELECT] statements. 2632 ** 2633 ** Applications that need to process SQL from untrusted sources 2634 ** might also consider lowering resource limits using [sqlite3_limit()] 2635 ** and limiting database size using the [max_page_count] [PRAGMA] 2636 ** in addition to using an authorizer. 2637 ** 2638 ** ^(Only a single authorizer can be in place on a database connection 2639 ** at a time. Each call to sqlite3_set_authorizer overrides the 2640 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2641 ** The authorizer is disabled by default. 2642 ** 2643 ** The authorizer callback must not do anything that will modify 2644 ** the database connection that invoked the authorizer callback. 2645 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2646 ** database connections for the meaning of "modify" in this paragraph. 2647 ** 2648 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2649 ** statement might be re-prepared during [sqlite3_step()] due to a 2650 ** schema change. Hence, the application should ensure that the 2651 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2652 ** 2653 ** ^Note that the authorizer callback is invoked only during 2654 ** [sqlite3_prepare()] or its variants. Authorization is not 2655 ** performed during statement evaluation in [sqlite3_step()], unless 2656 ** as stated in the previous paragraph, sqlite3_step() invokes 2657 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2658 */ 2659 SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer( 2660 sqlite3*, 2661 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2662 void *pUserData 2663 ); 2664 2665 /* 2666 ** CAPI3REF: Authorizer Return Codes 2667 ** 2668 ** The [sqlite3_set_authorizer | authorizer callback function] must 2669 ** return either [SQLITE_OK] or one of these two constants in order 2670 ** to signal SQLite whether or not the action is permitted. See the 2671 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2672 ** information. 2673 ** 2674 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2675 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2676 */ 2677 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2678 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2679 2680 /* 2681 ** CAPI3REF: Authorizer Action Codes 2682 ** 2683 ** The [sqlite3_set_authorizer()] interface registers a callback function 2684 ** that is invoked to authorize certain SQL statement actions. The 2685 ** second parameter to the callback is an integer code that specifies 2686 ** what action is being authorized. These are the integer action codes that 2687 ** the authorizer callback may be passed. 2688 ** 2689 ** These action code values signify what kind of operation is to be 2690 ** authorized. The 3rd and 4th parameters to the authorization 2691 ** callback function will be parameters or NULL depending on which of these 2692 ** codes is used as the second parameter. ^(The 5th parameter to the 2693 ** authorizer callback is the name of the database ("main", "temp", 2694 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2695 ** is the name of the inner-most trigger or view that is responsible for 2696 ** the access attempt or NULL if this access attempt is directly from 2697 ** top-level SQL code. 2698 */ 2699 /******************************************* 3rd ************ 4th ***********/ 2700 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2701 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2702 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2703 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2704 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2705 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2706 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2707 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2708 #define SQLITE_DELETE 9 /* Table Name NULL */ 2709 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2710 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2711 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2712 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2713 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2714 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2715 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2716 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2717 #define SQLITE_INSERT 18 /* Table Name NULL */ 2718 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2719 #define SQLITE_READ 20 /* Table Name Column Name */ 2720 #define SQLITE_SELECT 21 /* NULL NULL */ 2721 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2722 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2723 #define SQLITE_ATTACH 24 /* Filename NULL */ 2724 #define SQLITE_DETACH 25 /* Database Name NULL */ 2725 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2726 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2727 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2728 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2729 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2730 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2731 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2732 #define SQLITE_COPY 0 /* No longer used */ 2733 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2734 2735 /* 2736 ** CAPI3REF: Tracing And Profiling Functions 2737 ** METHOD: sqlite3 2738 ** 2739 ** These routines register callback functions that can be used for 2740 ** tracing and profiling the execution of SQL statements. 2741 ** 2742 ** ^The callback function registered by sqlite3_trace() is invoked at 2743 ** various times when an SQL statement is being run by [sqlite3_step()]. 2744 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2745 ** SQL statement text as the statement first begins executing. 2746 ** ^(Additional sqlite3_trace() callbacks might occur 2747 ** as each triggered subprogram is entered. The callbacks for triggers 2748 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2749 ** 2750 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2751 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2752 ** 2753 ** ^The callback function registered by sqlite3_profile() is invoked 2754 ** as each SQL statement finishes. ^The profile callback contains 2755 ** the original statement text and an estimate of wall-clock time 2756 ** of how long that statement took to run. ^The profile callback 2757 ** time is in units of nanoseconds, however the current implementation 2758 ** is only capable of millisecond resolution so the six least significant 2759 ** digits in the time are meaningless. Future versions of SQLite 2760 ** might provide greater resolution on the profiler callback. The 2761 ** sqlite3_profile() function is considered experimental and is 2762 ** subject to change in future versions of SQLite. 2763 */ 2764 SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2765 SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*, 2766 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2767 2768 /* 2769 ** CAPI3REF: Query Progress Callbacks 2770 ** METHOD: sqlite3 2771 ** 2772 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2773 ** function X to be invoked periodically during long running calls to 2774 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2775 ** database connection D. An example use for this 2776 ** interface is to keep a GUI updated during a large query. 2777 ** 2778 ** ^The parameter P is passed through as the only parameter to the 2779 ** callback function X. ^The parameter N is the approximate number of 2780 ** [virtual machine instructions] that are evaluated between successive 2781 ** invocations of the callback X. ^If N is less than one then the progress 2782 ** handler is disabled. 2783 ** 2784 ** ^Only a single progress handler may be defined at one time per 2785 ** [database connection]; setting a new progress handler cancels the 2786 ** old one. ^Setting parameter X to NULL disables the progress handler. 2787 ** ^The progress handler is also disabled by setting N to a value less 2788 ** than 1. 2789 ** 2790 ** ^If the progress callback returns non-zero, the operation is 2791 ** interrupted. This feature can be used to implement a 2792 ** "Cancel" button on a GUI progress dialog box. 2793 ** 2794 ** The progress handler callback must not do anything that will modify 2795 ** the database connection that invoked the progress handler. 2796 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2797 ** database connections for the meaning of "modify" in this paragraph. 2798 ** 2799 */ 2800 SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2801 2802 /* 2803 ** CAPI3REF: Opening A New Database Connection 2804 ** CONSTRUCTOR: sqlite3 2805 ** 2806 ** ^These routines open an SQLite database file as specified by the 2807 ** filename argument. ^The filename argument is interpreted as UTF-8 for 2808 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2809 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2810 ** returned in *ppDb, even if an error occurs. The only exception is that 2811 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2812 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2813 ** object.)^ ^(If the database is opened (and/or created) successfully, then 2814 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2815 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2816 ** an English language description of the error following a failure of any 2817 ** of the sqlite3_open() routines. 2818 ** 2819 ** ^The default encoding will be UTF-8 for databases created using 2820 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2821 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 2822 ** 2823 ** Whether or not an error occurs when it is opened, resources 2824 ** associated with the [database connection] handle should be released by 2825 ** passing it to [sqlite3_close()] when it is no longer required. 2826 ** 2827 ** The sqlite3_open_v2() interface works like sqlite3_open() 2828 ** except that it accepts two additional parameters for additional control 2829 ** over the new database connection. ^(The flags parameter to 2830 ** sqlite3_open_v2() can take one of 2831 ** the following three values, optionally combined with the 2832 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2833 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2834 ** 2835 ** <dl> 2836 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2837 ** <dd>The database is opened in read-only mode. If the database does not 2838 ** already exist, an error is returned.</dd>)^ 2839 ** 2840 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2841 ** <dd>The database is opened for reading and writing if possible, or reading 2842 ** only if the file is write protected by the operating system. In either 2843 ** case the database must already exist, otherwise an error is returned.</dd>)^ 2844 ** 2845 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2846 ** <dd>The database is opened for reading and writing, and is created if 2847 ** it does not already exist. This is the behavior that is always used for 2848 ** sqlite3_open() and sqlite3_open16().</dd>)^ 2849 ** </dl> 2850 ** 2851 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 2852 ** combinations shown above optionally combined with other 2853 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2854 ** then the behavior is undefined. 2855 ** 2856 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2857 ** opens in the multi-thread [threading mode] as long as the single-thread 2858 ** mode has not been set at compile-time or start-time. ^If the 2859 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2860 ** in the serialized [threading mode] unless single-thread was 2861 ** previously selected at compile-time or start-time. 2862 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2863 ** eligible to use [shared cache mode], regardless of whether or not shared 2864 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2865 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2866 ** participate in [shared cache mode] even if it is enabled. 2867 ** 2868 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 2869 ** [sqlite3_vfs] object that defines the operating system interface that 2870 ** the new database connection should use. ^If the fourth parameter is 2871 ** a NULL pointer then the default [sqlite3_vfs] object is used. 2872 ** 2873 ** ^If the filename is ":memory:", then a private, temporary in-memory database 2874 ** is created for the connection. ^This in-memory database will vanish when 2875 ** the database connection is closed. Future versions of SQLite might 2876 ** make use of additional special filenames that begin with the ":" character. 2877 ** It is recommended that when a database filename actually does begin with 2878 ** a ":" character you should prefix the filename with a pathname such as 2879 ** "./" to avoid ambiguity. 2880 ** 2881 ** ^If the filename is an empty string, then a private, temporary 2882 ** on-disk database will be created. ^This private database will be 2883 ** automatically deleted as soon as the database connection is closed. 2884 ** 2885 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2886 ** 2887 ** ^If [URI filename] interpretation is enabled, and the filename argument 2888 ** begins with "file:", then the filename is interpreted as a URI. ^URI 2889 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2890 ** set in the fourth argument to sqlite3_open_v2(), or if it has 2891 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2892 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2893 ** As of SQLite version 3.7.7, URI filename interpretation is turned off 2894 ** by default, but future releases of SQLite might enable URI filename 2895 ** interpretation by default. See "[URI filenames]" for additional 2896 ** information. 2897 ** 2898 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2899 ** authority, then it must be either an empty string or the string 2900 ** "localhost". ^If the authority is not an empty string or "localhost", an 2901 ** error is returned to the caller. ^The fragment component of a URI, if 2902 ** present, is ignored. 2903 ** 2904 ** ^SQLite uses the path component of the URI as the name of the disk file 2905 ** which contains the database. ^If the path begins with a '/' character, 2906 ** then it is interpreted as an absolute path. ^If the path does not begin 2907 ** with a '/' (meaning that the authority section is omitted from the URI) 2908 ** then the path is interpreted as a relative path. 2909 ** ^(On windows, the first component of an absolute path 2910 ** is a drive specification (e.g. "C:").)^ 2911 ** 2912 ** [[core URI query parameters]] 2913 ** The query component of a URI may contain parameters that are interpreted 2914 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2915 ** SQLite and its built-in [VFSes] interpret the 2916 ** following query parameters: 2917 ** 2918 ** <ul> 2919 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2920 ** a VFS object that provides the operating system interface that should 2921 ** be used to access the database file on disk. ^If this option is set to 2922 ** an empty string the default VFS object is used. ^Specifying an unknown 2923 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2924 ** present, then the VFS specified by the option takes precedence over 2925 ** the value passed as the fourth parameter to sqlite3_open_v2(). 2926 ** 2927 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2928 ** "rwc", or "memory". Attempting to set it to any other value is 2929 ** an error)^. 2930 ** ^If "ro" is specified, then the database is opened for read-only 2931 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2932 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 2933 ** "rw", then the database is opened for read-write (but not create) 2934 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2935 ** been set. ^Value "rwc" is equivalent to setting both 2936 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2937 ** set to "memory" then a pure [in-memory database] that never reads 2938 ** or writes from disk is used. ^It is an error to specify a value for 2939 ** the mode parameter that is less restrictive than that specified by 2940 ** the flags passed in the third parameter to sqlite3_open_v2(). 2941 ** 2942 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2943 ** "private". ^Setting it to "shared" is equivalent to setting the 2944 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2945 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2946 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2947 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2948 ** a URI filename, its value overrides any behavior requested by setting 2949 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2950 ** 2951 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 2952 ** [powersafe overwrite] property does or does not apply to the 2953 ** storage media on which the database file resides. 2954 ** 2955 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2956 ** which if set disables file locking in rollback journal modes. This 2957 ** is useful for accessing a database on a filesystem that does not 2958 ** support locking. Caution: Database corruption might result if two 2959 ** or more processes write to the same database and any one of those 2960 ** processes uses nolock=1. 2961 ** 2962 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2963 ** parameter that indicates that the database file is stored on 2964 ** read-only media. ^When immutable is set, SQLite assumes that the 2965 ** database file cannot be changed, even by a process with higher 2966 ** privilege, and so the database is opened read-only and all locking 2967 ** and change detection is disabled. Caution: Setting the immutable 2968 ** property on a database file that does in fact change can result 2969 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2970 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 2971 ** 2972 ** </ul> 2973 ** 2974 ** ^Specifying an unknown parameter in the query component of a URI is not an 2975 ** error. Future versions of SQLite might understand additional query 2976 ** parameters. See "[query parameters with special meaning to SQLite]" for 2977 ** additional information. 2978 ** 2979 ** [[URI filename examples]] <h3>URI filename examples</h3> 2980 ** 2981 ** <table border="1" align=center cellpadding=5> 2982 ** <tr><th> URI filenames <th> Results 2983 ** <tr><td> file:data.db <td> 2984 ** Open the file "data.db" in the current directory. 2985 ** <tr><td> file:/home/fred/data.db<br> 2986 ** file:///home/fred/data.db <br> 2987 ** file://localhost/home/fred/data.db <br> <td> 2988 ** Open the database file "/home/fred/data.db". 2989 ** <tr><td> file://darkstar/home/fred/data.db <td> 2990 ** An error. "darkstar" is not a recognized authority. 2991 ** <tr><td style="white-space:nowrap"> 2992 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2993 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2994 ** C:. Note that the %20 escaping in this example is not strictly 2995 ** necessary - space characters can be used literally 2996 ** in URI filenames. 2997 ** <tr><td> file:data.db?mode=ro&cache=private <td> 2998 ** Open file "data.db" in the current directory for read-only access. 2999 ** Regardless of whether or not shared-cache mode is enabled by 3000 ** default, use a private cache. 3001 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3002 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3003 ** that uses dot-files in place of posix advisory locking. 3004 ** <tr><td> file:data.db?mode=readonly <td> 3005 ** An error. "readonly" is not a valid option for the "mode" parameter. 3006 ** </table> 3007 ** 3008 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3009 ** query components of a URI. A hexadecimal escape sequence consists of a 3010 ** percent sign - "%" - followed by exactly two hexadecimal digits 3011 ** specifying an octet value. ^Before the path or query components of a 3012 ** URI filename are interpreted, they are encoded using UTF-8 and all 3013 ** hexadecimal escape sequences replaced by a single byte containing the 3014 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3015 ** the results are undefined. 3016 ** 3017 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3018 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3019 ** codepage is currently defined. Filenames containing international 3020 ** characters must be converted to UTF-8 prior to passing them into 3021 ** sqlite3_open() or sqlite3_open_v2(). 3022 ** 3023 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3024 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3025 ** features that require the use of temporary files may fail. 3026 ** 3027 ** See also: [sqlite3_temp_directory] 3028 */ 3029 SQLITE_API int SQLITE_STDCALL sqlite3_open( 3030 const char *filename, /* Database filename (UTF-8) */ 3031 sqlite3 **ppDb /* OUT: SQLite db handle */ 3032 ); 3033 SQLITE_API int SQLITE_STDCALL sqlite3_open16( 3034 const void *filename, /* Database filename (UTF-16) */ 3035 sqlite3 **ppDb /* OUT: SQLite db handle */ 3036 ); 3037 SQLITE_API int SQLITE_STDCALL sqlite3_open_v2( 3038 const char *filename, /* Database filename (UTF-8) */ 3039 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3040 int flags, /* Flags */ 3041 const char *zVfs /* Name of VFS module to use */ 3042 ); 3043 3044 /* 3045 ** CAPI3REF: Obtain Values For URI Parameters 3046 ** 3047 ** These are utility routines, useful to VFS implementations, that check 3048 ** to see if a database file was a URI that contained a specific query 3049 ** parameter, and if so obtains the value of that query parameter. 3050 ** 3051 ** If F is the database filename pointer passed into the xOpen() method of 3052 ** a VFS implementation when the flags parameter to xOpen() has one or 3053 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3054 ** P is the name of the query parameter, then 3055 ** sqlite3_uri_parameter(F,P) returns the value of the P 3056 ** parameter if it exists or a NULL pointer if P does not appear as a 3057 ** query parameter on F. If P is a query parameter of F 3058 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3059 ** a pointer to an empty string. 3060 ** 3061 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3062 ** parameter and returns true (1) or false (0) according to the value 3063 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3064 ** value of query parameter P is one of "yes", "true", or "on" in any 3065 ** case or if the value begins with a non-zero number. The 3066 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3067 ** query parameter P is one of "no", "false", or "off" in any case or 3068 ** if the value begins with a numeric zero. If P is not a query 3069 ** parameter on F or if the value of P is does not match any of the 3070 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3071 ** 3072 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3073 ** 64-bit signed integer and returns that integer, or D if P does not 3074 ** exist. If the value of P is something other than an integer, then 3075 ** zero is returned. 3076 ** 3077 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3078 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3079 ** is not a database file pathname pointer that SQLite passed into the xOpen 3080 ** VFS method, then the behavior of this routine is undefined and probably 3081 ** undesirable. 3082 */ 3083 SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3084 SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3085 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3086 3087 3088 /* 3089 ** CAPI3REF: Error Codes And Messages 3090 ** METHOD: sqlite3 3091 ** 3092 ** ^If the most recent sqlite3_* API call associated with 3093 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3094 ** returns the numeric [result code] or [extended result code] for that 3095 ** API call. 3096 ** If the most recent API call was successful, 3097 ** then the return value from sqlite3_errcode() is undefined. 3098 ** ^The sqlite3_extended_errcode() 3099 ** interface is the same except that it always returns the 3100 ** [extended result code] even when extended result codes are 3101 ** disabled. 3102 ** 3103 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3104 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3105 ** ^(Memory to hold the error message string is managed internally. 3106 ** The application does not need to worry about freeing the result. 3107 ** However, the error string might be overwritten or deallocated by 3108 ** subsequent calls to other SQLite interface functions.)^ 3109 ** 3110 ** ^The sqlite3_errstr() interface returns the English-language text 3111 ** that describes the [result code], as UTF-8. 3112 ** ^(Memory to hold the error message string is managed internally 3113 ** and must not be freed by the application)^. 3114 ** 3115 ** When the serialized [threading mode] is in use, it might be the 3116 ** case that a second error occurs on a separate thread in between 3117 ** the time of the first error and the call to these interfaces. 3118 ** When that happens, the second error will be reported since these 3119 ** interfaces always report the most recent result. To avoid 3120 ** this, each thread can obtain exclusive use of the [database connection] D 3121 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3122 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3123 ** all calls to the interfaces listed here are completed. 3124 ** 3125 ** If an interface fails with SQLITE_MISUSE, that means the interface 3126 ** was invoked incorrectly by the application. In that case, the 3127 ** error code and message may or may not be set. 3128 */ 3129 SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db); 3130 SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db); 3131 SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*); 3132 SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*); 3133 SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int); 3134 3135 /* 3136 ** CAPI3REF: Prepared Statement Object 3137 ** KEYWORDS: {prepared statement} {prepared statements} 3138 ** 3139 ** An instance of this object represents a single SQL statement that 3140 ** has been compiled into binary form and is ready to be evaluated. 3141 ** 3142 ** Think of each SQL statement as a separate computer program. The 3143 ** original SQL text is source code. A prepared statement object 3144 ** is the compiled object code. All SQL must be converted into a 3145 ** prepared statement before it can be run. 3146 ** 3147 ** The life-cycle of a prepared statement object usually goes like this: 3148 ** 3149 ** <ol> 3150 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3151 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3152 ** interfaces. 3153 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3154 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3155 ** to step 2. Do this zero or more times. 3156 ** <li> Destroy the object using [sqlite3_finalize()]. 3157 ** </ol> 3158 */ 3159 typedef struct sqlite3_stmt sqlite3_stmt; 3160 3161 /* 3162 ** CAPI3REF: Run-time Limits 3163 ** METHOD: sqlite3 3164 ** 3165 ** ^(This interface allows the size of various constructs to be limited 3166 ** on a connection by connection basis. The first parameter is the 3167 ** [database connection] whose limit is to be set or queried. The 3168 ** second parameter is one of the [limit categories] that define a 3169 ** class of constructs to be size limited. The third parameter is the 3170 ** new limit for that construct.)^ 3171 ** 3172 ** ^If the new limit is a negative number, the limit is unchanged. 3173 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3174 ** [limits | hard upper bound] 3175 ** set at compile-time by a C preprocessor macro called 3176 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3177 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3178 ** ^Attempts to increase a limit above its hard upper bound are 3179 ** silently truncated to the hard upper bound. 3180 ** 3181 ** ^Regardless of whether or not the limit was changed, the 3182 ** [sqlite3_limit()] interface returns the prior value of the limit. 3183 ** ^Hence, to find the current value of a limit without changing it, 3184 ** simply invoke this interface with the third parameter set to -1. 3185 ** 3186 ** Run-time limits are intended for use in applications that manage 3187 ** both their own internal database and also databases that are controlled 3188 ** by untrusted external sources. An example application might be a 3189 ** web browser that has its own databases for storing history and 3190 ** separate databases controlled by JavaScript applications downloaded 3191 ** off the Internet. The internal databases can be given the 3192 ** large, default limits. Databases managed by external sources can 3193 ** be given much smaller limits designed to prevent a denial of service 3194 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3195 ** interface to further control untrusted SQL. The size of the database 3196 ** created by an untrusted script can be contained using the 3197 ** [max_page_count] [PRAGMA]. 3198 ** 3199 ** New run-time limit categories may be added in future releases. 3200 */ 3201 SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal); 3202 3203 /* 3204 ** CAPI3REF: Run-Time Limit Categories 3205 ** KEYWORDS: {limit category} {*limit categories} 3206 ** 3207 ** These constants define various performance limits 3208 ** that can be lowered at run-time using [sqlite3_limit()]. 3209 ** The synopsis of the meanings of the various limits is shown below. 3210 ** Additional information is available at [limits | Limits in SQLite]. 3211 ** 3212 ** <dl> 3213 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3214 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3215 ** 3216 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3217 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3218 ** 3219 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3220 ** <dd>The maximum number of columns in a table definition or in the 3221 ** result set of a [SELECT] or the maximum number of columns in an index 3222 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3223 ** 3224 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3225 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3226 ** 3227 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3228 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3229 ** 3230 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3231 ** <dd>The maximum number of instructions in a virtual machine program 3232 ** used to implement an SQL statement. This limit is not currently 3233 ** enforced, though that might be added in some future release of 3234 ** SQLite.</dd>)^ 3235 ** 3236 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3237 ** <dd>The maximum number of arguments on a function.</dd>)^ 3238 ** 3239 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3240 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3241 ** 3242 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3243 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3244 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3245 ** [GLOB] operators.</dd>)^ 3246 ** 3247 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3248 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3249 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3250 ** 3251 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3252 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3253 ** 3254 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3255 ** <dd>The maximum number of auxiliary worker threads that a single 3256 ** [prepared statement] may start.</dd>)^ 3257 ** </dl> 3258 */ 3259 #define SQLITE_LIMIT_LENGTH 0 3260 #define SQLITE_LIMIT_SQL_LENGTH 1 3261 #define SQLITE_LIMIT_COLUMN 2 3262 #define SQLITE_LIMIT_EXPR_DEPTH 3 3263 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3264 #define SQLITE_LIMIT_VDBE_OP 5 3265 #define SQLITE_LIMIT_FUNCTION_ARG 6 3266 #define SQLITE_LIMIT_ATTACHED 7 3267 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3268 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3269 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3270 #define SQLITE_LIMIT_WORKER_THREADS 11 3271 3272 /* 3273 ** CAPI3REF: Compiling An SQL Statement 3274 ** KEYWORDS: {SQL statement compiler} 3275 ** METHOD: sqlite3 3276 ** CONSTRUCTOR: sqlite3_stmt 3277 ** 3278 ** To execute an SQL query, it must first be compiled into a byte-code 3279 ** program using one of these routines. 3280 ** 3281 ** The first argument, "db", is a [database connection] obtained from a 3282 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3283 ** [sqlite3_open16()]. The database connection must not have been closed. 3284 ** 3285 ** The second argument, "zSql", is the statement to be compiled, encoded 3286 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3287 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3288 ** use UTF-16. 3289 ** 3290 ** ^If the nByte argument is negative, then zSql is read up to the 3291 ** first zero terminator. ^If nByte is positive, then it is the 3292 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3293 ** statement is generated. 3294 ** If the caller knows that the supplied string is nul-terminated, then 3295 ** there is a small performance advantage to passing an nByte parameter that 3296 ** is the number of bytes in the input string <i>including</i> 3297 ** the nul-terminator. 3298 ** 3299 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3300 ** past the end of the first SQL statement in zSql. These routines only 3301 ** compile the first statement in zSql, so *pzTail is left pointing to 3302 ** what remains uncompiled. 3303 ** 3304 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3305 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3306 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3307 ** string or a comment) then *ppStmt is set to NULL. 3308 ** The calling procedure is responsible for deleting the compiled 3309 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3310 ** ppStmt may not be NULL. 3311 ** 3312 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3313 ** otherwise an [error code] is returned. 3314 ** 3315 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3316 ** recommended for all new programs. The two older interfaces are retained 3317 ** for backwards compatibility, but their use is discouraged. 3318 ** ^In the "v2" interfaces, the prepared statement 3319 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3320 ** original SQL text. This causes the [sqlite3_step()] interface to 3321 ** behave differently in three ways: 3322 ** 3323 ** <ol> 3324 ** <li> 3325 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3326 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3327 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3328 ** retries will occur before sqlite3_step() gives up and returns an error. 3329 ** </li> 3330 ** 3331 ** <li> 3332 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3333 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3334 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3335 ** and the application would have to make a second call to [sqlite3_reset()] 3336 ** in order to find the underlying cause of the problem. With the "v2" prepare 3337 ** interfaces, the underlying reason for the error is returned immediately. 3338 ** </li> 3339 ** 3340 ** <li> 3341 ** ^If the specific value bound to [parameter | host parameter] in the 3342 ** WHERE clause might influence the choice of query plan for a statement, 3343 ** then the statement will be automatically recompiled, as if there had been 3344 ** a schema change, on the first [sqlite3_step()] call following any change 3345 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3346 ** ^The specific value of WHERE-clause [parameter] might influence the 3347 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3348 ** or [GLOB] operator or if the parameter is compared to an indexed column 3349 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3350 ** </li> 3351 ** </ol> 3352 */ 3353 SQLITE_API int SQLITE_STDCALL sqlite3_prepare( 3354 sqlite3 *db, /* Database handle */ 3355 const char *zSql, /* SQL statement, UTF-8 encoded */ 3356 int nByte, /* Maximum length of zSql in bytes. */ 3357 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3358 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3359 ); 3360 SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2( 3361 sqlite3 *db, /* Database handle */ 3362 const char *zSql, /* SQL statement, UTF-8 encoded */ 3363 int nByte, /* Maximum length of zSql in bytes. */ 3364 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3365 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3366 ); 3367 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16( 3368 sqlite3 *db, /* Database handle */ 3369 const void *zSql, /* SQL statement, UTF-16 encoded */ 3370 int nByte, /* Maximum length of zSql in bytes. */ 3371 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3372 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3373 ); 3374 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2( 3375 sqlite3 *db, /* Database handle */ 3376 const void *zSql, /* SQL statement, UTF-16 encoded */ 3377 int nByte, /* Maximum length of zSql in bytes. */ 3378 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3379 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3380 ); 3381 3382 /* 3383 ** CAPI3REF: Retrieving Statement SQL 3384 ** METHOD: sqlite3_stmt 3385 ** 3386 ** ^This interface can be used to retrieve a saved copy of the original 3387 ** SQL text used to create a [prepared statement] if that statement was 3388 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3389 */ 3390 SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt); 3391 3392 /* 3393 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3394 ** METHOD: sqlite3_stmt 3395 ** 3396 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3397 ** and only if the [prepared statement] X makes no direct changes to 3398 ** the content of the database file. 3399 ** 3400 ** Note that [application-defined SQL functions] or 3401 ** [virtual tables] might change the database indirectly as a side effect. 3402 ** ^(For example, if an application defines a function "eval()" that 3403 ** calls [sqlite3_exec()], then the following SQL statement would 3404 ** change the database file through side-effects: 3405 ** 3406 ** <blockquote><pre> 3407 ** SELECT eval('DELETE FROM t1') FROM t2; 3408 ** </pre></blockquote> 3409 ** 3410 ** But because the [SELECT] statement does not change the database file 3411 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3412 ** 3413 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3414 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3415 ** since the statements themselves do not actually modify the database but 3416 ** rather they control the timing of when other statements modify the 3417 ** database. ^The [ATTACH] and [DETACH] statements also cause 3418 ** sqlite3_stmt_readonly() to return true since, while those statements 3419 ** change the configuration of a database connection, they do not make 3420 ** changes to the content of the database files on disk. 3421 */ 3422 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3423 3424 /* 3425 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3426 ** METHOD: sqlite3_stmt 3427 ** 3428 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3429 ** [prepared statement] S has been stepped at least once using 3430 ** [sqlite3_step(S)] but has neither run to completion (returned 3431 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3432 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3433 ** interface returns false if S is a NULL pointer. If S is not a 3434 ** NULL pointer and is not a pointer to a valid [prepared statement] 3435 ** object, then the behavior is undefined and probably undesirable. 3436 ** 3437 ** This interface can be used in combination [sqlite3_next_stmt()] 3438 ** to locate all prepared statements associated with a database 3439 ** connection that are in need of being reset. This can be used, 3440 ** for example, in diagnostic routines to search for prepared 3441 ** statements that are holding a transaction open. 3442 */ 3443 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*); 3444 3445 /* 3446 ** CAPI3REF: Dynamically Typed Value Object 3447 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3448 ** 3449 ** SQLite uses the sqlite3_value object to represent all values 3450 ** that can be stored in a database table. SQLite uses dynamic typing 3451 ** for the values it stores. ^Values stored in sqlite3_value objects 3452 ** can be integers, floating point values, strings, BLOBs, or NULL. 3453 ** 3454 ** An sqlite3_value object may be either "protected" or "unprotected". 3455 ** Some interfaces require a protected sqlite3_value. Other interfaces 3456 ** will accept either a protected or an unprotected sqlite3_value. 3457 ** Every interface that accepts sqlite3_value arguments specifies 3458 ** whether or not it requires a protected sqlite3_value. The 3459 ** [sqlite3_value_dup()] interface can be used to construct a new 3460 ** protected sqlite3_value from an unprotected sqlite3_value. 3461 ** 3462 ** The terms "protected" and "unprotected" refer to whether or not 3463 ** a mutex is held. An internal mutex is held for a protected 3464 ** sqlite3_value object but no mutex is held for an unprotected 3465 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3466 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3467 ** or if SQLite is run in one of reduced mutex modes 3468 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3469 ** then there is no distinction between protected and unprotected 3470 ** sqlite3_value objects and they can be used interchangeably. However, 3471 ** for maximum code portability it is recommended that applications 3472 ** still make the distinction between protected and unprotected 3473 ** sqlite3_value objects even when not strictly required. 3474 ** 3475 ** ^The sqlite3_value objects that are passed as parameters into the 3476 ** implementation of [application-defined SQL functions] are protected. 3477 ** ^The sqlite3_value object returned by 3478 ** [sqlite3_column_value()] is unprotected. 3479 ** Unprotected sqlite3_value objects may only be used with 3480 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3481 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3482 ** interfaces require protected sqlite3_value objects. 3483 */ 3484 typedef struct Mem sqlite3_value; 3485 3486 /* 3487 ** CAPI3REF: SQL Function Context Object 3488 ** 3489 ** The context in which an SQL function executes is stored in an 3490 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3491 ** is always first parameter to [application-defined SQL functions]. 3492 ** The application-defined SQL function implementation will pass this 3493 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3494 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3495 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3496 ** and/or [sqlite3_set_auxdata()]. 3497 */ 3498 typedef struct sqlite3_context sqlite3_context; 3499 3500 /* 3501 ** CAPI3REF: Binding Values To Prepared Statements 3502 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3503 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3504 ** METHOD: sqlite3_stmt 3505 ** 3506 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3507 ** literals may be replaced by a [parameter] that matches one of following 3508 ** templates: 3509 ** 3510 ** <ul> 3511 ** <li> ? 3512 ** <li> ?NNN 3513 ** <li> :VVV 3514 ** <li> @VVV 3515 ** <li> $VVV 3516 ** </ul> 3517 ** 3518 ** In the templates above, NNN represents an integer literal, 3519 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3520 ** parameters (also called "host parameter names" or "SQL parameters") 3521 ** can be set using the sqlite3_bind_*() routines defined here. 3522 ** 3523 ** ^The first argument to the sqlite3_bind_*() routines is always 3524 ** a pointer to the [sqlite3_stmt] object returned from 3525 ** [sqlite3_prepare_v2()] or its variants. 3526 ** 3527 ** ^The second argument is the index of the SQL parameter to be set. 3528 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3529 ** SQL parameter is used more than once, second and subsequent 3530 ** occurrences have the same index as the first occurrence. 3531 ** ^The index for named parameters can be looked up using the 3532 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3533 ** for "?NNN" parameters is the value of NNN. 3534 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3535 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3536 ** 3537 ** ^The third argument is the value to bind to the parameter. 3538 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3539 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3540 ** is ignored and the end result is the same as sqlite3_bind_null(). 3541 ** 3542 ** ^(In those routines that have a fourth argument, its value is the 3543 ** number of bytes in the parameter. To be clear: the value is the 3544 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3545 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3546 ** is negative, then the length of the string is 3547 ** the number of bytes up to the first zero terminator. 3548 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3549 ** the behavior is undefined. 3550 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3551 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3552 ** that parameter must be the byte offset 3553 ** where the NUL terminator would occur assuming the string were NUL 3554 ** terminated. If any NUL characters occur at byte offsets less than 3555 ** the value of the fourth parameter then the resulting string value will 3556 ** contain embedded NULs. The result of expressions involving strings 3557 ** with embedded NULs is undefined. 3558 ** 3559 ** ^The fifth argument to the BLOB and string binding interfaces 3560 ** is a destructor used to dispose of the BLOB or 3561 ** string after SQLite has finished with it. ^The destructor is called 3562 ** to dispose of the BLOB or string even if the call to bind API fails. 3563 ** ^If the fifth argument is 3564 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3565 ** information is in static, unmanaged space and does not need to be freed. 3566 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3567 ** SQLite makes its own private copy of the data immediately, before 3568 ** the sqlite3_bind_*() routine returns. 3569 ** 3570 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3571 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3572 ** to specify the encoding of the text in the third parameter. If 3573 ** the sixth argument to sqlite3_bind_text64() is not one of the 3574 ** allowed values shown above, or if the text encoding is different 3575 ** from the encoding specified by the sixth parameter, then the behavior 3576 ** is undefined. 3577 ** 3578 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3579 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3580 ** (just an integer to hold its size) while it is being processed. 3581 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3582 ** content is later written using 3583 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3584 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3585 ** 3586 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3587 ** for the [prepared statement] or with a prepared statement for which 3588 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3589 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3590 ** routine is passed a [prepared statement] that has been finalized, the 3591 ** result is undefined and probably harmful. 3592 ** 3593 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3594 ** ^Unbound parameters are interpreted as NULL. 3595 ** 3596 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3597 ** [error code] if anything goes wrong. 3598 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3599 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3600 ** [SQLITE_MAX_LENGTH]. 3601 ** ^[SQLITE_RANGE] is returned if the parameter 3602 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3603 ** 3604 ** See also: [sqlite3_bind_parameter_count()], 3605 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3606 */ 3607 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3608 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3609 void(*)(void*)); 3610 SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double); 3611 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int); 3612 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3613 SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int); 3614 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3615 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3616 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3617 void(*)(void*), unsigned char encoding); 3618 SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3619 SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3620 SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3621 3622 /* 3623 ** CAPI3REF: Number Of SQL Parameters 3624 ** METHOD: sqlite3_stmt 3625 ** 3626 ** ^This routine can be used to find the number of [SQL parameters] 3627 ** in a [prepared statement]. SQL parameters are tokens of the 3628 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3629 ** placeholders for values that are [sqlite3_bind_blob | bound] 3630 ** to the parameters at a later time. 3631 ** 3632 ** ^(This routine actually returns the index of the largest (rightmost) 3633 ** parameter. For all forms except ?NNN, this will correspond to the 3634 ** number of unique parameters. If parameters of the ?NNN form are used, 3635 ** there may be gaps in the list.)^ 3636 ** 3637 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3638 ** [sqlite3_bind_parameter_name()], and 3639 ** [sqlite3_bind_parameter_index()]. 3640 */ 3641 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*); 3642 3643 /* 3644 ** CAPI3REF: Name Of A Host Parameter 3645 ** METHOD: sqlite3_stmt 3646 ** 3647 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3648 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3649 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3650 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3651 ** respectively. 3652 ** In other words, the initial ":" or "$" or "@" or "?" 3653 ** is included as part of the name.)^ 3654 ** ^Parameters of the form "?" without a following integer have no name 3655 ** and are referred to as "nameless" or "anonymous parameters". 3656 ** 3657 ** ^The first host parameter has an index of 1, not 0. 3658 ** 3659 ** ^If the value N is out of range or if the N-th parameter is 3660 ** nameless, then NULL is returned. ^The returned string is 3661 ** always in UTF-8 encoding even if the named parameter was 3662 ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3663 ** [sqlite3_prepare16_v2()]. 3664 ** 3665 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3666 ** [sqlite3_bind_parameter_count()], and 3667 ** [sqlite3_bind_parameter_index()]. 3668 */ 3669 SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3670 3671 /* 3672 ** CAPI3REF: Index Of A Parameter With A Given Name 3673 ** METHOD: sqlite3_stmt 3674 ** 3675 ** ^Return the index of an SQL parameter given its name. ^The 3676 ** index value returned is suitable for use as the second 3677 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3678 ** is returned if no matching parameter is found. ^The parameter 3679 ** name must be given in UTF-8 even if the original statement 3680 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3681 ** 3682 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3683 ** [sqlite3_bind_parameter_count()], and 3684 ** [sqlite3_bind_parameter_name()]. 3685 */ 3686 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3687 3688 /* 3689 ** CAPI3REF: Reset All Bindings On A Prepared Statement 3690 ** METHOD: sqlite3_stmt 3691 ** 3692 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3693 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3694 ** ^Use this routine to reset all host parameters to NULL. 3695 */ 3696 SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*); 3697 3698 /* 3699 ** CAPI3REF: Number Of Columns In A Result Set 3700 ** METHOD: sqlite3_stmt 3701 ** 3702 ** ^Return the number of columns in the result set returned by the 3703 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3704 ** statement that does not return data (for example an [UPDATE]). 3705 ** 3706 ** See also: [sqlite3_data_count()] 3707 */ 3708 SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt); 3709 3710 /* 3711 ** CAPI3REF: Column Names In A Result Set 3712 ** METHOD: sqlite3_stmt 3713 ** 3714 ** ^These routines return the name assigned to a particular column 3715 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3716 ** interface returns a pointer to a zero-terminated UTF-8 string 3717 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3718 ** UTF-16 string. ^The first parameter is the [prepared statement] 3719 ** that implements the [SELECT] statement. ^The second parameter is the 3720 ** column number. ^The leftmost column is number 0. 3721 ** 3722 ** ^The returned string pointer is valid until either the [prepared statement] 3723 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3724 ** reprepared by the first call to [sqlite3_step()] for a particular run 3725 ** or until the next call to 3726 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3727 ** 3728 ** ^If sqlite3_malloc() fails during the processing of either routine 3729 ** (for example during a conversion from UTF-8 to UTF-16) then a 3730 ** NULL pointer is returned. 3731 ** 3732 ** ^The name of a result column is the value of the "AS" clause for 3733 ** that column, if there is an AS clause. If there is no AS clause 3734 ** then the name of the column is unspecified and may change from 3735 ** one release of SQLite to the next. 3736 */ 3737 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N); 3738 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N); 3739 3740 /* 3741 ** CAPI3REF: Source Of Data In A Query Result 3742 ** METHOD: sqlite3_stmt 3743 ** 3744 ** ^These routines provide a means to determine the database, table, and 3745 ** table column that is the origin of a particular result column in 3746 ** [SELECT] statement. 3747 ** ^The name of the database or table or column can be returned as 3748 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3749 ** the database name, the _table_ routines return the table name, and 3750 ** the origin_ routines return the column name. 3751 ** ^The returned string is valid until the [prepared statement] is destroyed 3752 ** using [sqlite3_finalize()] or until the statement is automatically 3753 ** reprepared by the first call to [sqlite3_step()] for a particular run 3754 ** or until the same information is requested 3755 ** again in a different encoding. 3756 ** 3757 ** ^The names returned are the original un-aliased names of the 3758 ** database, table, and column. 3759 ** 3760 ** ^The first argument to these interfaces is a [prepared statement]. 3761 ** ^These functions return information about the Nth result column returned by 3762 ** the statement, where N is the second function argument. 3763 ** ^The left-most column is column 0 for these routines. 3764 ** 3765 ** ^If the Nth column returned by the statement is an expression or 3766 ** subquery and is not a column value, then all of these functions return 3767 ** NULL. ^These routine might also return NULL if a memory allocation error 3768 ** occurs. ^Otherwise, they return the name of the attached database, table, 3769 ** or column that query result column was extracted from. 3770 ** 3771 ** ^As with all other SQLite APIs, those whose names end with "16" return 3772 ** UTF-16 encoded strings and the other functions return UTF-8. 3773 ** 3774 ** ^These APIs are only available if the library was compiled with the 3775 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3776 ** 3777 ** If two or more threads call one or more of these routines against the same 3778 ** prepared statement and column at the same time then the results are 3779 ** undefined. 3780 ** 3781 ** If two or more threads call one or more 3782 ** [sqlite3_column_database_name | column metadata interfaces] 3783 ** for the same [prepared statement] and result column 3784 ** at the same time then the results are undefined. 3785 */ 3786 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int); 3787 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int); 3788 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int); 3789 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int); 3790 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int); 3791 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int); 3792 3793 /* 3794 ** CAPI3REF: Declared Datatype Of A Query Result 3795 ** METHOD: sqlite3_stmt 3796 ** 3797 ** ^(The first parameter is a [prepared statement]. 3798 ** If this statement is a [SELECT] statement and the Nth column of the 3799 ** returned result set of that [SELECT] is a table column (not an 3800 ** expression or subquery) then the declared type of the table 3801 ** column is returned.)^ ^If the Nth column of the result set is an 3802 ** expression or subquery, then a NULL pointer is returned. 3803 ** ^The returned string is always UTF-8 encoded. 3804 ** 3805 ** ^(For example, given the database schema: 3806 ** 3807 ** CREATE TABLE t1(c1 VARIANT); 3808 ** 3809 ** and the following statement to be compiled: 3810 ** 3811 ** SELECT c1 + 1, c1 FROM t1; 3812 ** 3813 ** this routine would return the string "VARIANT" for the second result 3814 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3815 ** 3816 ** ^SQLite uses dynamic run-time typing. ^So just because a column 3817 ** is declared to contain a particular type does not mean that the 3818 ** data stored in that column is of the declared type. SQLite is 3819 ** strongly typed, but the typing is dynamic not static. ^Type 3820 ** is associated with individual values, not with the containers 3821 ** used to hold those values. 3822 */ 3823 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int); 3824 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int); 3825 3826 /* 3827 ** CAPI3REF: Evaluate An SQL Statement 3828 ** METHOD: sqlite3_stmt 3829 ** 3830 ** After a [prepared statement] has been prepared using either 3831 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3832 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3833 ** must be called one or more times to evaluate the statement. 3834 ** 3835 ** The details of the behavior of the sqlite3_step() interface depend 3836 ** on whether the statement was prepared using the newer "v2" interface 3837 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3838 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3839 ** new "v2" interface is recommended for new applications but the legacy 3840 ** interface will continue to be supported. 3841 ** 3842 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3843 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3844 ** ^With the "v2" interface, any of the other [result codes] or 3845 ** [extended result codes] might be returned as well. 3846 ** 3847 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3848 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 3849 ** or occurs outside of an explicit transaction, then you can retry the 3850 ** statement. If the statement is not a [COMMIT] and occurs within an 3851 ** explicit transaction then you should rollback the transaction before 3852 ** continuing. 3853 ** 3854 ** ^[SQLITE_DONE] means that the statement has finished executing 3855 ** successfully. sqlite3_step() should not be called again on this virtual 3856 ** machine without first calling [sqlite3_reset()] to reset the virtual 3857 ** machine back to its initial state. 3858 ** 3859 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3860 ** is returned each time a new row of data is ready for processing by the 3861 ** caller. The values may be accessed using the [column access functions]. 3862 ** sqlite3_step() is called again to retrieve the next row of data. 3863 ** 3864 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3865 ** violation) has occurred. sqlite3_step() should not be called again on 3866 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 3867 ** ^With the legacy interface, a more specific error code (for example, 3868 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3869 ** can be obtained by calling [sqlite3_reset()] on the 3870 ** [prepared statement]. ^In the "v2" interface, 3871 ** the more specific error code is returned directly by sqlite3_step(). 3872 ** 3873 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3874 ** Perhaps it was called on a [prepared statement] that has 3875 ** already been [sqlite3_finalize | finalized] or on one that had 3876 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3877 ** be the case that the same database connection is being used by two or 3878 ** more threads at the same moment in time. 3879 ** 3880 ** For all versions of SQLite up to and including 3.6.23.1, a call to 3881 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 3882 ** other than [SQLITE_ROW] before any subsequent invocation of 3883 ** sqlite3_step(). Failure to reset the prepared statement using 3884 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3885 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3886 ** calling [sqlite3_reset()] automatically in this circumstance rather 3887 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3888 ** break because any application that ever receives an SQLITE_MISUSE error 3889 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3890 ** can be used to restore the legacy behavior. 3891 ** 3892 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3893 ** API always returns a generic error code, [SQLITE_ERROR], following any 3894 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3895 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3896 ** specific [error codes] that better describes the error. 3897 ** We admit that this is a goofy design. The problem has been fixed 3898 ** with the "v2" interface. If you prepare all of your SQL statements 3899 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3900 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3901 ** then the more specific [error codes] are returned directly 3902 ** by sqlite3_step(). The use of the "v2" interface is recommended. 3903 */ 3904 SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*); 3905 3906 /* 3907 ** CAPI3REF: Number of columns in a result set 3908 ** METHOD: sqlite3_stmt 3909 ** 3910 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 3911 ** current row of the result set of [prepared statement] P. 3912 ** ^If prepared statement P does not have results ready to return 3913 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3914 ** interfaces) then sqlite3_data_count(P) returns 0. 3915 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3916 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3917 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3918 ** will return non-zero if previous call to [sqlite3_step](P) returned 3919 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3920 ** where it always returns zero since each step of that multi-step 3921 ** pragma returns 0 columns of data. 3922 ** 3923 ** See also: [sqlite3_column_count()] 3924 */ 3925 SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt); 3926 3927 /* 3928 ** CAPI3REF: Fundamental Datatypes 3929 ** KEYWORDS: SQLITE_TEXT 3930 ** 3931 ** ^(Every value in SQLite has one of five fundamental datatypes: 3932 ** 3933 ** <ul> 3934 ** <li> 64-bit signed integer 3935 ** <li> 64-bit IEEE floating point number 3936 ** <li> string 3937 ** <li> BLOB 3938 ** <li> NULL 3939 ** </ul>)^ 3940 ** 3941 ** These constants are codes for each of those types. 3942 ** 3943 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3944 ** for a completely different meaning. Software that links against both 3945 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3946 ** SQLITE_TEXT. 3947 */ 3948 #define SQLITE_INTEGER 1 3949 #define SQLITE_FLOAT 2 3950 #define SQLITE_BLOB 4 3951 #define SQLITE_NULL 5 3952 #ifdef SQLITE_TEXT 3953 # undef SQLITE_TEXT 3954 #else 3955 # define SQLITE_TEXT 3 3956 #endif 3957 #define SQLITE3_TEXT 3 3958 3959 /* 3960 ** CAPI3REF: Result Values From A Query 3961 ** KEYWORDS: {column access functions} 3962 ** METHOD: sqlite3_stmt 3963 ** 3964 ** ^These routines return information about a single column of the current 3965 ** result row of a query. ^In every case the first argument is a pointer 3966 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3967 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3968 ** and the second argument is the index of the column for which information 3969 ** should be returned. ^The leftmost column of the result set has the index 0. 3970 ** ^The number of columns in the result can be determined using 3971 ** [sqlite3_column_count()]. 3972 ** 3973 ** If the SQL statement does not currently point to a valid row, or if the 3974 ** column index is out of range, the result is undefined. 3975 ** These routines may only be called when the most recent call to 3976 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3977 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3978 ** If any of these routines are called after [sqlite3_reset()] or 3979 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3980 ** something other than [SQLITE_ROW], the results are undefined. 3981 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3982 ** are called from a different thread while any of these routines 3983 ** are pending, then the results are undefined. 3984 ** 3985 ** ^The sqlite3_column_type() routine returns the 3986 ** [SQLITE_INTEGER | datatype code] for the initial data type 3987 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3988 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3989 ** returned by sqlite3_column_type() is only meaningful if no type 3990 ** conversions have occurred as described below. After a type conversion, 3991 ** the value returned by sqlite3_column_type() is undefined. Future 3992 ** versions of SQLite may change the behavior of sqlite3_column_type() 3993 ** following a type conversion. 3994 ** 3995 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3996 ** routine returns the number of bytes in that BLOB or string. 3997 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3998 ** the string to UTF-8 and then returns the number of bytes. 3999 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4000 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4001 ** the number of bytes in that string. 4002 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4003 ** 4004 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4005 ** routine returns the number of bytes in that BLOB or string. 4006 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4007 ** the string to UTF-16 and then returns the number of bytes. 4008 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4009 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4010 ** the number of bytes in that string. 4011 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4012 ** 4013 ** ^The values returned by [sqlite3_column_bytes()] and 4014 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4015 ** of the string. ^For clarity: the values returned by 4016 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4017 ** bytes in the string, not the number of characters. 4018 ** 4019 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4020 ** even empty strings, are always zero-terminated. ^The return 4021 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4022 ** 4023 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4024 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4025 ** an unprotected sqlite3_value object may only be used safely with 4026 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4027 ** If the [unprotected sqlite3_value] object returned by 4028 ** [sqlite3_column_value()] is used in any other way, including calls 4029 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4030 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4031 ** 4032 ** These routines attempt to convert the value where appropriate. ^For 4033 ** example, if the internal representation is FLOAT and a text result 4034 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4035 ** conversion automatically. ^(The following table details the conversions 4036 ** that are applied: 4037 ** 4038 ** <blockquote> 4039 ** <table border="1"> 4040 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4041 ** 4042 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4043 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4044 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4045 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4046 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4047 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4048 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4049 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4050 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4051 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4052 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4053 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4054 ** <tr><td> TEXT <td> BLOB <td> No change 4055 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4056 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4057 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4058 ** </table> 4059 ** </blockquote>)^ 4060 ** 4061 ** Note that when type conversions occur, pointers returned by prior 4062 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4063 ** sqlite3_column_text16() may be invalidated. 4064 ** Type conversions and pointer invalidations might occur 4065 ** in the following cases: 4066 ** 4067 ** <ul> 4068 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4069 ** sqlite3_column_text16() is called. A zero-terminator might 4070 ** need to be added to the string.</li> 4071 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4072 ** sqlite3_column_text16() is called. The content must be converted 4073 ** to UTF-16.</li> 4074 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4075 ** sqlite3_column_text() is called. The content must be converted 4076 ** to UTF-8.</li> 4077 ** </ul> 4078 ** 4079 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4080 ** not invalidate a prior pointer, though of course the content of the buffer 4081 ** that the prior pointer references will have been modified. Other kinds 4082 ** of conversion are done in place when it is possible, but sometimes they 4083 ** are not possible and in those cases prior pointers are invalidated. 4084 ** 4085 ** The safest policy is to invoke these routines 4086 ** in one of the following ways: 4087 ** 4088 ** <ul> 4089 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4090 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4091 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4092 ** </ul> 4093 ** 4094 ** In other words, you should call sqlite3_column_text(), 4095 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4096 ** into the desired format, then invoke sqlite3_column_bytes() or 4097 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4098 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4099 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4100 ** with calls to sqlite3_column_bytes(). 4101 ** 4102 ** ^The pointers returned are valid until a type conversion occurs as 4103 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4104 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4105 ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4106 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4107 ** [sqlite3_free()]. 4108 ** 4109 ** ^(If a memory allocation error occurs during the evaluation of any 4110 ** of these routines, a default value is returned. The default value 4111 ** is either the integer 0, the floating point number 0.0, or a NULL 4112 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4113 ** [SQLITE_NOMEM].)^ 4114 */ 4115 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol); 4116 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4117 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4118 SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol); 4119 SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol); 4120 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol); 4121 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol); 4122 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol); 4123 SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol); 4124 SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol); 4125 4126 /* 4127 ** CAPI3REF: Destroy A Prepared Statement Object 4128 ** DESTRUCTOR: sqlite3_stmt 4129 ** 4130 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4131 ** ^If the most recent evaluation of the statement encountered no errors 4132 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4133 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4134 ** sqlite3_finalize(S) returns the appropriate [error code] or 4135 ** [extended error code]. 4136 ** 4137 ** ^The sqlite3_finalize(S) routine can be called at any point during 4138 ** the life cycle of [prepared statement] S: 4139 ** before statement S is ever evaluated, after 4140 ** one or more calls to [sqlite3_reset()], or after any call 4141 ** to [sqlite3_step()] regardless of whether or not the statement has 4142 ** completed execution. 4143 ** 4144 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4145 ** 4146 ** The application must finalize every [prepared statement] in order to avoid 4147 ** resource leaks. It is a grievous error for the application to try to use 4148 ** a prepared statement after it has been finalized. Any use of a prepared 4149 ** statement after it has been finalized can result in undefined and 4150 ** undesirable behavior such as segfaults and heap corruption. 4151 */ 4152 SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt); 4153 4154 /* 4155 ** CAPI3REF: Reset A Prepared Statement Object 4156 ** METHOD: sqlite3_stmt 4157 ** 4158 ** The sqlite3_reset() function is called to reset a [prepared statement] 4159 ** object back to its initial state, ready to be re-executed. 4160 ** ^Any SQL statement variables that had values bound to them using 4161 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4162 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4163 ** 4164 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4165 ** back to the beginning of its program. 4166 ** 4167 ** ^If the most recent call to [sqlite3_step(S)] for the 4168 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4169 ** or if [sqlite3_step(S)] has never before been called on S, 4170 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4171 ** 4172 ** ^If the most recent call to [sqlite3_step(S)] for the 4173 ** [prepared statement] S indicated an error, then 4174 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4175 ** 4176 ** ^The [sqlite3_reset(S)] interface does not change the values 4177 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4178 */ 4179 SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt); 4180 4181 /* 4182 ** CAPI3REF: Create Or Redefine SQL Functions 4183 ** KEYWORDS: {function creation routines} 4184 ** KEYWORDS: {application-defined SQL function} 4185 ** KEYWORDS: {application-defined SQL functions} 4186 ** METHOD: sqlite3 4187 ** 4188 ** ^These functions (collectively known as "function creation routines") 4189 ** are used to add SQL functions or aggregates or to redefine the behavior 4190 ** of existing SQL functions or aggregates. The only differences between 4191 ** these routines are the text encoding expected for 4192 ** the second parameter (the name of the function being created) 4193 ** and the presence or absence of a destructor callback for 4194 ** the application data pointer. 4195 ** 4196 ** ^The first parameter is the [database connection] to which the SQL 4197 ** function is to be added. ^If an application uses more than one database 4198 ** connection then application-defined SQL functions must be added 4199 ** to each database connection separately. 4200 ** 4201 ** ^The second parameter is the name of the SQL function to be created or 4202 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4203 ** representation, exclusive of the zero-terminator. ^Note that the name 4204 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4205 ** ^Any attempt to create a function with a longer name 4206 ** will result in [SQLITE_MISUSE] being returned. 4207 ** 4208 ** ^The third parameter (nArg) 4209 ** is the number of arguments that the SQL function or 4210 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4211 ** aggregate may take any number of arguments between 0 and the limit 4212 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4213 ** parameter is less than -1 or greater than 127 then the behavior is 4214 ** undefined. 4215 ** 4216 ** ^The fourth parameter, eTextRep, specifies what 4217 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4218 ** its parameters. The application should set this parameter to 4219 ** [SQLITE_UTF16LE] if the function implementation invokes 4220 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4221 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4222 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4223 ** otherwise. ^The same SQL function may be registered multiple times using 4224 ** different preferred text encodings, with different implementations for 4225 ** each encoding. 4226 ** ^When multiple implementations of the same function are available, SQLite 4227 ** will pick the one that involves the least amount of data conversion. 4228 ** 4229 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4230 ** to signal that the function will always return the same result given 4231 ** the same inputs within a single SQL statement. Most SQL functions are 4232 ** deterministic. The built-in [random()] SQL function is an example of a 4233 ** function that is not deterministic. The SQLite query planner is able to 4234 ** perform additional optimizations on deterministic functions, so use 4235 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4236 ** 4237 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4238 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4239 ** 4240 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4241 ** pointers to C-language functions that implement the SQL function or 4242 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4243 ** callback only; NULL pointers must be passed as the xStep and xFinal 4244 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4245 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4246 ** SQL function or aggregate, pass NULL pointers for all three function 4247 ** callbacks. 4248 ** 4249 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4250 ** then it is destructor for the application data pointer. 4251 ** The destructor is invoked when the function is deleted, either by being 4252 ** overloaded or when the database connection closes.)^ 4253 ** ^The destructor is also invoked if the call to 4254 ** sqlite3_create_function_v2() fails. 4255 ** ^When the destructor callback of the tenth parameter is invoked, it 4256 ** is passed a single argument which is a copy of the application data 4257 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4258 ** 4259 ** ^It is permitted to register multiple implementations of the same 4260 ** functions with the same name but with either differing numbers of 4261 ** arguments or differing preferred text encodings. ^SQLite will use 4262 ** the implementation that most closely matches the way in which the 4263 ** SQL function is used. ^A function implementation with a non-negative 4264 ** nArg parameter is a better match than a function implementation with 4265 ** a negative nArg. ^A function where the preferred text encoding 4266 ** matches the database encoding is a better 4267 ** match than a function where the encoding is different. 4268 ** ^A function where the encoding difference is between UTF16le and UTF16be 4269 ** is a closer match than a function where the encoding difference is 4270 ** between UTF8 and UTF16. 4271 ** 4272 ** ^Built-in functions may be overloaded by new application-defined functions. 4273 ** 4274 ** ^An application-defined function is permitted to call other 4275 ** SQLite interfaces. However, such calls must not 4276 ** close the database connection nor finalize or reset the prepared 4277 ** statement in which the function is running. 4278 */ 4279 SQLITE_API int SQLITE_STDCALL sqlite3_create_function( 4280 sqlite3 *db, 4281 const char *zFunctionName, 4282 int nArg, 4283 int eTextRep, 4284 void *pApp, 4285 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4286 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4287 void (*xFinal)(sqlite3_context*) 4288 ); 4289 SQLITE_API int SQLITE_STDCALL sqlite3_create_function16( 4290 sqlite3 *db, 4291 const void *zFunctionName, 4292 int nArg, 4293 int eTextRep, 4294 void *pApp, 4295 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4296 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4297 void (*xFinal)(sqlite3_context*) 4298 ); 4299 SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2( 4300 sqlite3 *db, 4301 const char *zFunctionName, 4302 int nArg, 4303 int eTextRep, 4304 void *pApp, 4305 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4306 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4307 void (*xFinal)(sqlite3_context*), 4308 void(*xDestroy)(void*) 4309 ); 4310 4311 /* 4312 ** CAPI3REF: Text Encodings 4313 ** 4314 ** These constant define integer codes that represent the various 4315 ** text encodings supported by SQLite. 4316 */ 4317 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4318 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4319 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4320 #define SQLITE_UTF16 4 /* Use native byte order */ 4321 #define SQLITE_ANY 5 /* Deprecated */ 4322 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4323 4324 /* 4325 ** CAPI3REF: Function Flags 4326 ** 4327 ** These constants may be ORed together with the 4328 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4329 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4330 ** [sqlite3_create_function_v2()]. 4331 */ 4332 #define SQLITE_DETERMINISTIC 0x800 4333 4334 /* 4335 ** CAPI3REF: Deprecated Functions 4336 ** DEPRECATED 4337 ** 4338 ** These functions are [deprecated]. In order to maintain 4339 ** backwards compatibility with older code, these functions continue 4340 ** to be supported. However, new applications should avoid 4341 ** the use of these functions. To encourage programmers to avoid 4342 ** these functions, we will not explain what they do. 4343 */ 4344 #ifndef SQLITE_OMIT_DEPRECATED 4345 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*); 4346 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*); 4347 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4348 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void); 4349 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void); 4350 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4351 void*,sqlite3_int64); 4352 #endif 4353 4354 /* 4355 ** CAPI3REF: Obtaining SQL Values 4356 ** METHOD: sqlite3_value 4357 ** 4358 ** The C-language implementation of SQL functions and aggregates uses 4359 ** this set of interface routines to access the parameter values on 4360 ** the function or aggregate. 4361 ** 4362 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4363 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4364 ** define callbacks that implement the SQL functions and aggregates. 4365 ** The 3rd parameter to these callbacks is an array of pointers to 4366 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4367 ** each parameter to the SQL function. These routines are used to 4368 ** extract values from the [sqlite3_value] objects. 4369 ** 4370 ** These routines work only with [protected sqlite3_value] objects. 4371 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4372 ** object results in undefined behavior. 4373 ** 4374 ** ^These routines work just like the corresponding [column access functions] 4375 ** except that these routines take a single [protected sqlite3_value] object 4376 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4377 ** 4378 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4379 ** in the native byte-order of the host machine. ^The 4380 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4381 ** extract UTF-16 strings as big-endian and little-endian respectively. 4382 ** 4383 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4384 ** numeric affinity to the value. This means that an attempt is 4385 ** made to convert the value to an integer or floating point. If 4386 ** such a conversion is possible without loss of information (in other 4387 ** words, if the value is a string that looks like a number) 4388 ** then the conversion is performed. Otherwise no conversion occurs. 4389 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4390 ** 4391 ** Please pay particular attention to the fact that the pointer returned 4392 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4393 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4394 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4395 ** or [sqlite3_value_text16()]. 4396 ** 4397 ** These routines must be called from the same thread as 4398 ** the SQL function that supplied the [sqlite3_value*] parameters. 4399 */ 4400 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*); 4401 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*); 4402 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*); 4403 SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*); 4404 SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*); 4405 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*); 4406 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*); 4407 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*); 4408 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*); 4409 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*); 4410 SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*); 4411 SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*); 4412 4413 /* 4414 ** CAPI3REF: Finding The Subtype Of SQL Values 4415 ** METHOD: sqlite3_value 4416 ** 4417 ** The sqlite3_value_subtype(V) function returns the subtype for 4418 ** an [application-defined SQL function] argument V. The subtype 4419 ** information can be used to pass a limited amount of context from 4420 ** one SQL function to another. Use the [sqlite3_result_subtype()] 4421 ** routine to set the subtype for the return value of an SQL function. 4422 ** 4423 ** SQLite makes no use of subtype itself. It merely passes the subtype 4424 ** from the result of one [application-defined SQL function] into the 4425 ** input of another. 4426 */ 4427 SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*); 4428 4429 /* 4430 ** CAPI3REF: Copy And Free SQL Values 4431 ** METHOD: sqlite3_value 4432 ** 4433 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4434 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4435 ** is a [protected sqlite3_value] object even if the input is not. 4436 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4437 ** memory allocation fails. 4438 ** 4439 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4440 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4441 ** then sqlite3_value_free(V) is a harmless no-op. 4442 */ 4443 SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*); 4444 SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*); 4445 4446 /* 4447 ** CAPI3REF: Obtain Aggregate Function Context 4448 ** METHOD: sqlite3_context 4449 ** 4450 ** Implementations of aggregate SQL functions use this 4451 ** routine to allocate memory for storing their state. 4452 ** 4453 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4454 ** for a particular aggregate function, SQLite 4455 ** allocates N of memory, zeroes out that memory, and returns a pointer 4456 ** to the new memory. ^On second and subsequent calls to 4457 ** sqlite3_aggregate_context() for the same aggregate function instance, 4458 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4459 ** called once for each invocation of the xStep callback and then one 4460 ** last time when the xFinal callback is invoked. ^(When no rows match 4461 ** an aggregate query, the xStep() callback of the aggregate function 4462 ** implementation is never called and xFinal() is called exactly once. 4463 ** In those cases, sqlite3_aggregate_context() might be called for the 4464 ** first time from within xFinal().)^ 4465 ** 4466 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4467 ** when first called if N is less than or equal to zero or if a memory 4468 ** allocate error occurs. 4469 ** 4470 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4471 ** determined by the N parameter on first successful call. Changing the 4472 ** value of N in subsequent call to sqlite3_aggregate_context() within 4473 ** the same aggregate function instance will not resize the memory 4474 ** allocation.)^ Within the xFinal callback, it is customary to set 4475 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4476 ** pointless memory allocations occur. 4477 ** 4478 ** ^SQLite automatically frees the memory allocated by 4479 ** sqlite3_aggregate_context() when the aggregate query concludes. 4480 ** 4481 ** The first parameter must be a copy of the 4482 ** [sqlite3_context | SQL function context] that is the first parameter 4483 ** to the xStep or xFinal callback routine that implements the aggregate 4484 ** function. 4485 ** 4486 ** This routine must be called from the same thread in which 4487 ** the aggregate SQL function is running. 4488 */ 4489 SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4490 4491 /* 4492 ** CAPI3REF: User Data For Functions 4493 ** METHOD: sqlite3_context 4494 ** 4495 ** ^The sqlite3_user_data() interface returns a copy of 4496 ** the pointer that was the pUserData parameter (the 5th parameter) 4497 ** of the [sqlite3_create_function()] 4498 ** and [sqlite3_create_function16()] routines that originally 4499 ** registered the application defined function. 4500 ** 4501 ** This routine must be called from the same thread in which 4502 ** the application-defined function is running. 4503 */ 4504 SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*); 4505 4506 /* 4507 ** CAPI3REF: Database Connection For Functions 4508 ** METHOD: sqlite3_context 4509 ** 4510 ** ^The sqlite3_context_db_handle() interface returns a copy of 4511 ** the pointer to the [database connection] (the 1st parameter) 4512 ** of the [sqlite3_create_function()] 4513 ** and [sqlite3_create_function16()] routines that originally 4514 ** registered the application defined function. 4515 */ 4516 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*); 4517 4518 /* 4519 ** CAPI3REF: Function Auxiliary Data 4520 ** METHOD: sqlite3_context 4521 ** 4522 ** These functions may be used by (non-aggregate) SQL functions to 4523 ** associate metadata with argument values. If the same value is passed to 4524 ** multiple invocations of the same SQL function during query execution, under 4525 ** some circumstances the associated metadata may be preserved. An example 4526 ** of where this might be useful is in a regular-expression matching 4527 ** function. The compiled version of the regular expression can be stored as 4528 ** metadata associated with the pattern string. 4529 ** Then as long as the pattern string remains the same, 4530 ** the compiled regular expression can be reused on multiple 4531 ** invocations of the same function. 4532 ** 4533 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4534 ** associated by the sqlite3_set_auxdata() function with the Nth argument 4535 ** value to the application-defined function. ^If there is no metadata 4536 ** associated with the function argument, this sqlite3_get_auxdata() interface 4537 ** returns a NULL pointer. 4538 ** 4539 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4540 ** argument of the application-defined function. ^Subsequent 4541 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4542 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4543 ** NULL if the metadata has been discarded. 4544 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4545 ** SQLite will invoke the destructor function X with parameter P exactly 4546 ** once, when the metadata is discarded. 4547 ** SQLite is free to discard the metadata at any time, including: <ul> 4548 ** <li> when the corresponding function parameter changes, or 4549 ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4550 ** SQL statement, or 4551 ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4552 ** <li> during the original sqlite3_set_auxdata() call when a memory 4553 ** allocation error occurs. </ul>)^ 4554 ** 4555 ** Note the last bullet in particular. The destructor X in 4556 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4557 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4558 ** should be called near the end of the function implementation and the 4559 ** function implementation should not make any use of P after 4560 ** sqlite3_set_auxdata() has been called. 4561 ** 4562 ** ^(In practice, metadata is preserved between function calls for 4563 ** function parameters that are compile-time constants, including literal 4564 ** values and [parameters] and expressions composed from the same.)^ 4565 ** 4566 ** These routines must be called from the same thread in which 4567 ** the SQL function is running. 4568 */ 4569 SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N); 4570 SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4571 4572 4573 /* 4574 ** CAPI3REF: Constants Defining Special Destructor Behavior 4575 ** 4576 ** These are special values for the destructor that is passed in as the 4577 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4578 ** argument is SQLITE_STATIC, it means that the content pointer is constant 4579 ** and will never change. It does not need to be destroyed. ^The 4580 ** SQLITE_TRANSIENT value means that the content will likely change in 4581 ** the near future and that SQLite should make its own private copy of 4582 ** the content before returning. 4583 ** 4584 ** The typedef is necessary to work around problems in certain 4585 ** C++ compilers. 4586 */ 4587 typedef void (*sqlite3_destructor_type)(void*); 4588 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4589 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4590 4591 /* 4592 ** CAPI3REF: Setting The Result Of An SQL Function 4593 ** METHOD: sqlite3_context 4594 ** 4595 ** These routines are used by the xFunc or xFinal callbacks that 4596 ** implement SQL functions and aggregates. See 4597 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4598 ** for additional information. 4599 ** 4600 ** These functions work very much like the [parameter binding] family of 4601 ** functions used to bind values to host parameters in prepared statements. 4602 ** Refer to the [SQL parameter] documentation for additional information. 4603 ** 4604 ** ^The sqlite3_result_blob() interface sets the result from 4605 ** an application-defined function to be the BLOB whose content is pointed 4606 ** to by the second parameter and which is N bytes long where N is the 4607 ** third parameter. 4608 ** 4609 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4610 ** interfaces set the result of the application-defined function to be 4611 ** a BLOB containing all zero bytes and N bytes in size. 4612 ** 4613 ** ^The sqlite3_result_double() interface sets the result from 4614 ** an application-defined function to be a floating point value specified 4615 ** by its 2nd argument. 4616 ** 4617 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4618 ** cause the implemented SQL function to throw an exception. 4619 ** ^SQLite uses the string pointed to by the 4620 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4621 ** as the text of an error message. ^SQLite interprets the error 4622 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4623 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4624 ** byte order. ^If the third parameter to sqlite3_result_error() 4625 ** or sqlite3_result_error16() is negative then SQLite takes as the error 4626 ** message all text up through the first zero character. 4627 ** ^If the third parameter to sqlite3_result_error() or 4628 ** sqlite3_result_error16() is non-negative then SQLite takes that many 4629 ** bytes (not characters) from the 2nd parameter as the error message. 4630 ** ^The sqlite3_result_error() and sqlite3_result_error16() 4631 ** routines make a private copy of the error message text before 4632 ** they return. Hence, the calling function can deallocate or 4633 ** modify the text after they return without harm. 4634 ** ^The sqlite3_result_error_code() function changes the error code 4635 ** returned by SQLite as a result of an error in a function. ^By default, 4636 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4637 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4638 ** 4639 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4640 ** error indicating that a string or BLOB is too long to represent. 4641 ** 4642 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4643 ** error indicating that a memory allocation failed. 4644 ** 4645 ** ^The sqlite3_result_int() interface sets the return value 4646 ** of the application-defined function to be the 32-bit signed integer 4647 ** value given in the 2nd argument. 4648 ** ^The sqlite3_result_int64() interface sets the return value 4649 ** of the application-defined function to be the 64-bit signed integer 4650 ** value given in the 2nd argument. 4651 ** 4652 ** ^The sqlite3_result_null() interface sets the return value 4653 ** of the application-defined function to be NULL. 4654 ** 4655 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4656 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4657 ** set the return value of the application-defined function to be 4658 ** a text string which is represented as UTF-8, UTF-16 native byte order, 4659 ** UTF-16 little endian, or UTF-16 big endian, respectively. 4660 ** ^The sqlite3_result_text64() interface sets the return value of an 4661 ** application-defined function to be a text string in an encoding 4662 ** specified by the fifth (and last) parameter, which must be one 4663 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4664 ** ^SQLite takes the text result from the application from 4665 ** the 2nd parameter of the sqlite3_result_text* interfaces. 4666 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4667 ** is negative, then SQLite takes result text from the 2nd parameter 4668 ** through the first zero character. 4669 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4670 ** is non-negative, then as many bytes (not characters) of the text 4671 ** pointed to by the 2nd parameter are taken as the application-defined 4672 ** function result. If the 3rd parameter is non-negative, then it 4673 ** must be the byte offset into the string where the NUL terminator would 4674 ** appear if the string where NUL terminated. If any NUL characters occur 4675 ** in the string at a byte offset that is less than the value of the 3rd 4676 ** parameter, then the resulting string will contain embedded NULs and the 4677 ** result of expressions operating on strings with embedded NULs is undefined. 4678 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4679 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4680 ** function as the destructor on the text or BLOB result when it has 4681 ** finished using that result. 4682 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4683 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4684 ** assumes that the text or BLOB result is in constant space and does not 4685 ** copy the content of the parameter nor call a destructor on the content 4686 ** when it has finished using that result. 4687 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4688 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4689 ** then SQLite makes a copy of the result into space obtained from 4690 ** from [sqlite3_malloc()] before it returns. 4691 ** 4692 ** ^The sqlite3_result_value() interface sets the result of 4693 ** the application-defined function to be a copy of the 4694 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4695 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4696 ** so that the [sqlite3_value] specified in the parameter may change or 4697 ** be deallocated after sqlite3_result_value() returns without harm. 4698 ** ^A [protected sqlite3_value] object may always be used where an 4699 ** [unprotected sqlite3_value] object is required, so either 4700 ** kind of [sqlite3_value] object can be used with this interface. 4701 ** 4702 ** If these routines are called from within the different thread 4703 ** than the one containing the application-defined function that received 4704 ** the [sqlite3_context] pointer, the results are undefined. 4705 */ 4706 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4707 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*, 4708 sqlite3_uint64,void(*)(void*)); 4709 SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double); 4710 SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int); 4711 SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int); 4712 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*); 4713 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*); 4714 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int); 4715 SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int); 4716 SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4717 SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*); 4718 SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4719 SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4720 void(*)(void*), unsigned char encoding); 4721 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4722 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4723 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4724 SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4725 SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n); 4726 SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4727 4728 4729 /* 4730 ** CAPI3REF: Setting The Subtype Of An SQL Function 4731 ** METHOD: sqlite3_context 4732 ** 4733 ** The sqlite3_result_subtype(C,T) function causes the subtype of 4734 ** the result from the [application-defined SQL function] with 4735 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 4736 ** of the subtype T are preserved in current versions of SQLite; 4737 ** higher order bits are discarded. 4738 ** The number of subtype bytes preserved by SQLite might increase 4739 ** in future releases of SQLite. 4740 */ 4741 SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int); 4742 4743 /* 4744 ** CAPI3REF: Define New Collating Sequences 4745 ** METHOD: sqlite3 4746 ** 4747 ** ^These functions add, remove, or modify a [collation] associated 4748 ** with the [database connection] specified as the first argument. 4749 ** 4750 ** ^The name of the collation is a UTF-8 string 4751 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4752 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4753 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4754 ** considered to be the same name. 4755 ** 4756 ** ^(The third argument (eTextRep) must be one of the constants: 4757 ** <ul> 4758 ** <li> [SQLITE_UTF8], 4759 ** <li> [SQLITE_UTF16LE], 4760 ** <li> [SQLITE_UTF16BE], 4761 ** <li> [SQLITE_UTF16], or 4762 ** <li> [SQLITE_UTF16_ALIGNED]. 4763 ** </ul>)^ 4764 ** ^The eTextRep argument determines the encoding of strings passed 4765 ** to the collating function callback, xCallback. 4766 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4767 ** force strings to be UTF16 with native byte order. 4768 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4769 ** on an even byte address. 4770 ** 4771 ** ^The fourth argument, pArg, is an application data pointer that is passed 4772 ** through as the first argument to the collating function callback. 4773 ** 4774 ** ^The fifth argument, xCallback, is a pointer to the collating function. 4775 ** ^Multiple collating functions can be registered using the same name but 4776 ** with different eTextRep parameters and SQLite will use whichever 4777 ** function requires the least amount of data transformation. 4778 ** ^If the xCallback argument is NULL then the collating function is 4779 ** deleted. ^When all collating functions having the same name are deleted, 4780 ** that collation is no longer usable. 4781 ** 4782 ** ^The collating function callback is invoked with a copy of the pArg 4783 ** application data pointer and with two strings in the encoding specified 4784 ** by the eTextRep argument. The collating function must return an 4785 ** integer that is negative, zero, or positive 4786 ** if the first string is less than, equal to, or greater than the second, 4787 ** respectively. A collating function must always return the same answer 4788 ** given the same inputs. If two or more collating functions are registered 4789 ** to the same collation name (using different eTextRep values) then all 4790 ** must give an equivalent answer when invoked with equivalent strings. 4791 ** The collating function must obey the following properties for all 4792 ** strings A, B, and C: 4793 ** 4794 ** <ol> 4795 ** <li> If A==B then B==A. 4796 ** <li> If A==B and B==C then A==C. 4797 ** <li> If A<B THEN B>A. 4798 ** <li> If A<B and B<C then A<C. 4799 ** </ol> 4800 ** 4801 ** If a collating function fails any of the above constraints and that 4802 ** collating function is registered and used, then the behavior of SQLite 4803 ** is undefined. 4804 ** 4805 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4806 ** with the addition that the xDestroy callback is invoked on pArg when 4807 ** the collating function is deleted. 4808 ** ^Collating functions are deleted when they are overridden by later 4809 ** calls to the collation creation functions or when the 4810 ** [database connection] is closed using [sqlite3_close()]. 4811 ** 4812 ** ^The xDestroy callback is <u>not</u> called if the 4813 ** sqlite3_create_collation_v2() function fails. Applications that invoke 4814 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4815 ** check the return code and dispose of the application data pointer 4816 ** themselves rather than expecting SQLite to deal with it for them. 4817 ** This is different from every other SQLite interface. The inconsistency 4818 ** is unfortunate but cannot be changed without breaking backwards 4819 ** compatibility. 4820 ** 4821 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4822 */ 4823 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation( 4824 sqlite3*, 4825 const char *zName, 4826 int eTextRep, 4827 void *pArg, 4828 int(*xCompare)(void*,int,const void*,int,const void*) 4829 ); 4830 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2( 4831 sqlite3*, 4832 const char *zName, 4833 int eTextRep, 4834 void *pArg, 4835 int(*xCompare)(void*,int,const void*,int,const void*), 4836 void(*xDestroy)(void*) 4837 ); 4838 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16( 4839 sqlite3*, 4840 const void *zName, 4841 int eTextRep, 4842 void *pArg, 4843 int(*xCompare)(void*,int,const void*,int,const void*) 4844 ); 4845 4846 /* 4847 ** CAPI3REF: Collation Needed Callbacks 4848 ** METHOD: sqlite3 4849 ** 4850 ** ^To avoid having to register all collation sequences before a database 4851 ** can be used, a single callback function may be registered with the 4852 ** [database connection] to be invoked whenever an undefined collation 4853 ** sequence is required. 4854 ** 4855 ** ^If the function is registered using the sqlite3_collation_needed() API, 4856 ** then it is passed the names of undefined collation sequences as strings 4857 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4858 ** the names are passed as UTF-16 in machine native byte order. 4859 ** ^A call to either function replaces the existing collation-needed callback. 4860 ** 4861 ** ^(When the callback is invoked, the first argument passed is a copy 4862 ** of the second argument to sqlite3_collation_needed() or 4863 ** sqlite3_collation_needed16(). The second argument is the database 4864 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4865 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4866 ** sequence function required. The fourth parameter is the name of the 4867 ** required collation sequence.)^ 4868 ** 4869 ** The callback function should register the desired collation using 4870 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4871 ** [sqlite3_create_collation_v2()]. 4872 */ 4873 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed( 4874 sqlite3*, 4875 void*, 4876 void(*)(void*,sqlite3*,int eTextRep,const char*) 4877 ); 4878 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16( 4879 sqlite3*, 4880 void*, 4881 void(*)(void*,sqlite3*,int eTextRep,const void*) 4882 ); 4883 4884 #ifdef SQLITE_HAS_CODEC 4885 /* 4886 ** Specify the key for an encrypted database. This routine should be 4887 ** called right after sqlite3_open(). 4888 ** 4889 ** The code to implement this API is not available in the public release 4890 ** of SQLite. 4891 */ 4892 SQLITE_API int SQLITE_STDCALL sqlite3_key( 4893 sqlite3 *db, /* Database to be rekeyed */ 4894 const void *pKey, int nKey /* The key */ 4895 ); 4896 SQLITE_API int SQLITE_STDCALL sqlite3_key_v2( 4897 sqlite3 *db, /* Database to be rekeyed */ 4898 const char *zDbName, /* Name of the database */ 4899 const void *pKey, int nKey /* The key */ 4900 ); 4901 4902 /* 4903 ** Change the key on an open database. If the current database is not 4904 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4905 ** database is decrypted. 4906 ** 4907 ** The code to implement this API is not available in the public release 4908 ** of SQLite. 4909 */ 4910 SQLITE_API int SQLITE_STDCALL sqlite3_rekey( 4911 sqlite3 *db, /* Database to be rekeyed */ 4912 const void *pKey, int nKey /* The new key */ 4913 ); 4914 SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2( 4915 sqlite3 *db, /* Database to be rekeyed */ 4916 const char *zDbName, /* Name of the database */ 4917 const void *pKey, int nKey /* The new key */ 4918 ); 4919 4920 /* 4921 ** Specify the activation key for a SEE database. Unless 4922 ** activated, none of the SEE routines will work. 4923 */ 4924 SQLITE_API void SQLITE_STDCALL sqlite3_activate_see( 4925 const char *zPassPhrase /* Activation phrase */ 4926 ); 4927 #endif 4928 4929 #ifdef SQLITE_ENABLE_CEROD 4930 /* 4931 ** Specify the activation key for a CEROD database. Unless 4932 ** activated, none of the CEROD routines will work. 4933 */ 4934 SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod( 4935 const char *zPassPhrase /* Activation phrase */ 4936 ); 4937 #endif 4938 4939 /* 4940 ** CAPI3REF: Suspend Execution For A Short Time 4941 ** 4942 ** The sqlite3_sleep() function causes the current thread to suspend execution 4943 ** for at least a number of milliseconds specified in its parameter. 4944 ** 4945 ** If the operating system does not support sleep requests with 4946 ** millisecond time resolution, then the time will be rounded up to 4947 ** the nearest second. The number of milliseconds of sleep actually 4948 ** requested from the operating system is returned. 4949 ** 4950 ** ^SQLite implements this interface by calling the xSleep() 4951 ** method of the default [sqlite3_vfs] object. If the xSleep() method 4952 ** of the default VFS is not implemented correctly, or not implemented at 4953 ** all, then the behavior of sqlite3_sleep() may deviate from the description 4954 ** in the previous paragraphs. 4955 */ 4956 SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int); 4957 4958 /* 4959 ** CAPI3REF: Name Of The Folder Holding Temporary Files 4960 ** 4961 ** ^(If this global variable is made to point to a string which is 4962 ** the name of a folder (a.k.a. directory), then all temporary files 4963 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4964 ** will be placed in that directory.)^ ^If this variable 4965 ** is a NULL pointer, then SQLite performs a search for an appropriate 4966 ** temporary file directory. 4967 ** 4968 ** Applications are strongly discouraged from using this global variable. 4969 ** It is required to set a temporary folder on Windows Runtime (WinRT). 4970 ** But for all other platforms, it is highly recommended that applications 4971 ** neither read nor write this variable. This global variable is a relic 4972 ** that exists for backwards compatibility of legacy applications and should 4973 ** be avoided in new projects. 4974 ** 4975 ** It is not safe to read or modify this variable in more than one 4976 ** thread at a time. It is not safe to read or modify this variable 4977 ** if a [database connection] is being used at the same time in a separate 4978 ** thread. 4979 ** It is intended that this variable be set once 4980 ** as part of process initialization and before any SQLite interface 4981 ** routines have been called and that this variable remain unchanged 4982 ** thereafter. 4983 ** 4984 ** ^The [temp_store_directory pragma] may modify this variable and cause 4985 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4986 ** the [temp_store_directory pragma] always assumes that any string 4987 ** that this variable points to is held in memory obtained from 4988 ** [sqlite3_malloc] and the pragma may attempt to free that memory 4989 ** using [sqlite3_free]. 4990 ** Hence, if this variable is modified directly, either it should be 4991 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4992 ** or else the use of the [temp_store_directory pragma] should be avoided. 4993 ** Except when requested by the [temp_store_directory pragma], SQLite 4994 ** does not free the memory that sqlite3_temp_directory points to. If 4995 ** the application wants that memory to be freed, it must do 4996 ** so itself, taking care to only do so after all [database connection] 4997 ** objects have been destroyed. 4998 ** 4999 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5000 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5001 ** features that require the use of temporary files may fail. Here is an 5002 ** example of how to do this using C++ with the Windows Runtime: 5003 ** 5004 ** <blockquote><pre> 5005 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5006 ** TemporaryFolder->Path->Data(); 5007 ** char zPathBuf[MAX_PATH + 1]; 5008 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5009 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5010 ** NULL, NULL); 5011 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5012 ** </pre></blockquote> 5013 */ 5014 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5015 5016 /* 5017 ** CAPI3REF: Name Of The Folder Holding Database Files 5018 ** 5019 ** ^(If this global variable is made to point to a string which is 5020 ** the name of a folder (a.k.a. directory), then all database files 5021 ** specified with a relative pathname and created or accessed by 5022 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5023 ** to be relative to that directory.)^ ^If this variable is a NULL 5024 ** pointer, then SQLite assumes that all database files specified 5025 ** with a relative pathname are relative to the current directory 5026 ** for the process. Only the windows VFS makes use of this global 5027 ** variable; it is ignored by the unix VFS. 5028 ** 5029 ** Changing the value of this variable while a database connection is 5030 ** open can result in a corrupt database. 5031 ** 5032 ** It is not safe to read or modify this variable in more than one 5033 ** thread at a time. It is not safe to read or modify this variable 5034 ** if a [database connection] is being used at the same time in a separate 5035 ** thread. 5036 ** It is intended that this variable be set once 5037 ** as part of process initialization and before any SQLite interface 5038 ** routines have been called and that this variable remain unchanged 5039 ** thereafter. 5040 ** 5041 ** ^The [data_store_directory pragma] may modify this variable and cause 5042 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5043 ** the [data_store_directory pragma] always assumes that any string 5044 ** that this variable points to is held in memory obtained from 5045 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5046 ** using [sqlite3_free]. 5047 ** Hence, if this variable is modified directly, either it should be 5048 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5049 ** or else the use of the [data_store_directory pragma] should be avoided. 5050 */ 5051 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5052 5053 /* 5054 ** CAPI3REF: Test For Auto-Commit Mode 5055 ** KEYWORDS: {autocommit mode} 5056 ** METHOD: sqlite3 5057 ** 5058 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5059 ** zero if the given database connection is or is not in autocommit mode, 5060 ** respectively. ^Autocommit mode is on by default. 5061 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5062 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5063 ** 5064 ** If certain kinds of errors occur on a statement within a multi-statement 5065 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5066 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5067 ** transaction might be rolled back automatically. The only way to 5068 ** find out whether SQLite automatically rolled back the transaction after 5069 ** an error is to use this function. 5070 ** 5071 ** If another thread changes the autocommit status of the database 5072 ** connection while this routine is running, then the return value 5073 ** is undefined. 5074 */ 5075 SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*); 5076 5077 /* 5078 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5079 ** METHOD: sqlite3_stmt 5080 ** 5081 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5082 ** to which a [prepared statement] belongs. ^The [database connection] 5083 ** returned by sqlite3_db_handle is the same [database connection] 5084 ** that was the first argument 5085 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5086 ** create the statement in the first place. 5087 */ 5088 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*); 5089 5090 /* 5091 ** CAPI3REF: Return The Filename For A Database Connection 5092 ** METHOD: sqlite3 5093 ** 5094 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5095 ** associated with database N of connection D. ^The main database file 5096 ** has the name "main". If there is no attached database N on the database 5097 ** connection D, or if database N is a temporary or in-memory database, then 5098 ** a NULL pointer is returned. 5099 ** 5100 ** ^The filename returned by this function is the output of the 5101 ** xFullPathname method of the [VFS]. ^In other words, the filename 5102 ** will be an absolute pathname, even if the filename used 5103 ** to open the database originally was a URI or relative pathname. 5104 */ 5105 SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5106 5107 /* 5108 ** CAPI3REF: Determine if a database is read-only 5109 ** METHOD: sqlite3 5110 ** 5111 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5112 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5113 ** the name of a database on connection D. 5114 */ 5115 SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5116 5117 /* 5118 ** CAPI3REF: Find the next prepared statement 5119 ** METHOD: sqlite3 5120 ** 5121 ** ^This interface returns a pointer to the next [prepared statement] after 5122 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5123 ** then this interface returns a pointer to the first prepared statement 5124 ** associated with the database connection pDb. ^If no prepared statement 5125 ** satisfies the conditions of this routine, it returns NULL. 5126 ** 5127 ** The [database connection] pointer D in a call to 5128 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5129 ** connection and in particular must not be a NULL pointer. 5130 */ 5131 SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5132 5133 /* 5134 ** CAPI3REF: Commit And Rollback Notification Callbacks 5135 ** METHOD: sqlite3 5136 ** 5137 ** ^The sqlite3_commit_hook() interface registers a callback 5138 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5139 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5140 ** for the same database connection is overridden. 5141 ** ^The sqlite3_rollback_hook() interface registers a callback 5142 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5143 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5144 ** for the same database connection is overridden. 5145 ** ^The pArg argument is passed through to the callback. 5146 ** ^If the callback on a commit hook function returns non-zero, 5147 ** then the commit is converted into a rollback. 5148 ** 5149 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5150 ** return the P argument from the previous call of the same function 5151 ** on the same [database connection] D, or NULL for 5152 ** the first call for each function on D. 5153 ** 5154 ** The commit and rollback hook callbacks are not reentrant. 5155 ** The callback implementation must not do anything that will modify 5156 ** the database connection that invoked the callback. Any actions 5157 ** to modify the database connection must be deferred until after the 5158 ** completion of the [sqlite3_step()] call that triggered the commit 5159 ** or rollback hook in the first place. 5160 ** Note that running any other SQL statements, including SELECT statements, 5161 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5162 ** the database connections for the meaning of "modify" in this paragraph. 5163 ** 5164 ** ^Registering a NULL function disables the callback. 5165 ** 5166 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5167 ** operation is allowed to continue normally. ^If the commit hook 5168 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5169 ** ^The rollback hook is invoked on a rollback that results from a commit 5170 ** hook returning non-zero, just as it would be with any other rollback. 5171 ** 5172 ** ^For the purposes of this API, a transaction is said to have been 5173 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5174 ** an error or constraint causes an implicit rollback to occur. 5175 ** ^The rollback callback is not invoked if a transaction is 5176 ** automatically rolled back because the database connection is closed. 5177 ** 5178 ** See also the [sqlite3_update_hook()] interface. 5179 */ 5180 SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5181 SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5182 5183 /* 5184 ** CAPI3REF: Data Change Notification Callbacks 5185 ** METHOD: sqlite3 5186 ** 5187 ** ^The sqlite3_update_hook() interface registers a callback function 5188 ** with the [database connection] identified by the first argument 5189 ** to be invoked whenever a row is updated, inserted or deleted in 5190 ** a rowid table. 5191 ** ^Any callback set by a previous call to this function 5192 ** for the same database connection is overridden. 5193 ** 5194 ** ^The second argument is a pointer to the function to invoke when a 5195 ** row is updated, inserted or deleted in a rowid table. 5196 ** ^The first argument to the callback is a copy of the third argument 5197 ** to sqlite3_update_hook(). 5198 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5199 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5200 ** to be invoked. 5201 ** ^The third and fourth arguments to the callback contain pointers to the 5202 ** database and table name containing the affected row. 5203 ** ^The final callback parameter is the [rowid] of the row. 5204 ** ^In the case of an update, this is the [rowid] after the update takes place. 5205 ** 5206 ** ^(The update hook is not invoked when internal system tables are 5207 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5208 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5209 ** 5210 ** ^In the current implementation, the update hook 5211 ** is not invoked when duplication rows are deleted because of an 5212 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5213 ** invoked when rows are deleted using the [truncate optimization]. 5214 ** The exceptions defined in this paragraph might change in a future 5215 ** release of SQLite. 5216 ** 5217 ** The update hook implementation must not do anything that will modify 5218 ** the database connection that invoked the update hook. Any actions 5219 ** to modify the database connection must be deferred until after the 5220 ** completion of the [sqlite3_step()] call that triggered the update hook. 5221 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5222 ** database connections for the meaning of "modify" in this paragraph. 5223 ** 5224 ** ^The sqlite3_update_hook(D,C,P) function 5225 ** returns the P argument from the previous call 5226 ** on the same [database connection] D, or NULL for 5227 ** the first call on D. 5228 ** 5229 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 5230 ** interfaces. 5231 */ 5232 SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( 5233 sqlite3*, 5234 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5235 void* 5236 ); 5237 5238 /* 5239 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5240 ** 5241 ** ^(This routine enables or disables the sharing of the database cache 5242 ** and schema data structures between [database connection | connections] 5243 ** to the same database. Sharing is enabled if the argument is true 5244 ** and disabled if the argument is false.)^ 5245 ** 5246 ** ^Cache sharing is enabled and disabled for an entire process. 5247 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5248 ** sharing was enabled or disabled for each thread separately. 5249 ** 5250 ** ^(The cache sharing mode set by this interface effects all subsequent 5251 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5252 ** Existing database connections continue use the sharing mode 5253 ** that was in effect at the time they were opened.)^ 5254 ** 5255 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5256 ** successfully. An [error code] is returned otherwise.)^ 5257 ** 5258 ** ^Shared cache is disabled by default. But this might change in 5259 ** future releases of SQLite. Applications that care about shared 5260 ** cache setting should set it explicitly. 5261 ** 5262 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5263 ** and will always return SQLITE_MISUSE. On those systems, 5264 ** shared cache mode should be enabled per-database connection via 5265 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5266 ** 5267 ** This interface is threadsafe on processors where writing a 5268 ** 32-bit integer is atomic. 5269 ** 5270 ** See Also: [SQLite Shared-Cache Mode] 5271 */ 5272 SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int); 5273 5274 /* 5275 ** CAPI3REF: Attempt To Free Heap Memory 5276 ** 5277 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5278 ** of heap memory by deallocating non-essential memory allocations 5279 ** held by the database library. Memory used to cache database 5280 ** pages to improve performance is an example of non-essential memory. 5281 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5282 ** which might be more or less than the amount requested. 5283 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5284 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5285 ** 5286 ** See also: [sqlite3_db_release_memory()] 5287 */ 5288 SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int); 5289 5290 /* 5291 ** CAPI3REF: Free Memory Used By A Database Connection 5292 ** METHOD: sqlite3 5293 ** 5294 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5295 ** memory as possible from database connection D. Unlike the 5296 ** [sqlite3_release_memory()] interface, this interface is in effect even 5297 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5298 ** omitted. 5299 ** 5300 ** See also: [sqlite3_release_memory()] 5301 */ 5302 SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*); 5303 5304 /* 5305 ** CAPI3REF: Impose A Limit On Heap Size 5306 ** 5307 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5308 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5309 ** ^SQLite strives to keep heap memory utilization below the soft heap 5310 ** limit by reducing the number of pages held in the page cache 5311 ** as heap memory usages approaches the limit. 5312 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5313 ** below the limit, it will exceed the limit rather than generate 5314 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5315 ** is advisory only. 5316 ** 5317 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5318 ** the soft heap limit prior to the call, or negative in the case of an 5319 ** error. ^If the argument N is negative 5320 ** then no change is made to the soft heap limit. Hence, the current 5321 ** size of the soft heap limit can be determined by invoking 5322 ** sqlite3_soft_heap_limit64() with a negative argument. 5323 ** 5324 ** ^If the argument N is zero then the soft heap limit is disabled. 5325 ** 5326 ** ^(The soft heap limit is not enforced in the current implementation 5327 ** if one or more of following conditions are true: 5328 ** 5329 ** <ul> 5330 ** <li> The soft heap limit is set to zero. 5331 ** <li> Memory accounting is disabled using a combination of the 5332 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5333 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5334 ** <li> An alternative page cache implementation is specified using 5335 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5336 ** <li> The page cache allocates from its own memory pool supplied 5337 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5338 ** from the heap. 5339 ** </ul>)^ 5340 ** 5341 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5342 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5343 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5344 ** the soft heap limit is enforced on every memory allocation. Without 5345 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5346 ** when memory is allocated by the page cache. Testing suggests that because 5347 ** the page cache is the predominate memory user in SQLite, most 5348 ** applications will achieve adequate soft heap limit enforcement without 5349 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5350 ** 5351 ** The circumstances under which SQLite will enforce the soft heap limit may 5352 ** changes in future releases of SQLite. 5353 */ 5354 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N); 5355 5356 /* 5357 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5358 ** DEPRECATED 5359 ** 5360 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5361 ** interface. This routine is provided for historical compatibility 5362 ** only. All new applications should use the 5363 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5364 */ 5365 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N); 5366 5367 5368 /* 5369 ** CAPI3REF: Extract Metadata About A Column Of A Table 5370 ** METHOD: sqlite3 5371 ** 5372 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5373 ** information about column C of table T in database D 5374 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5375 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5376 ** the final five arguments with appropriate values if the specified 5377 ** column exists. ^The sqlite3_table_column_metadata() interface returns 5378 ** SQLITE_ERROR and if the specified column does not exist. 5379 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5380 ** NULL pointer, then this routine simply checks for the existance of the 5381 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5382 ** does not. 5383 ** 5384 ** ^The column is identified by the second, third and fourth parameters to 5385 ** this function. ^(The second parameter is either the name of the database 5386 ** (i.e. "main", "temp", or an attached database) containing the specified 5387 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5388 ** for the table using the same algorithm used by the database engine to 5389 ** resolve unqualified table references. 5390 ** 5391 ** ^The third and fourth parameters to this function are the table and column 5392 ** name of the desired column, respectively. 5393 ** 5394 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5395 ** and subsequent parameters to this function. ^Any of these arguments may be 5396 ** NULL, in which case the corresponding element of metadata is omitted. 5397 ** 5398 ** ^(<blockquote> 5399 ** <table border="1"> 5400 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5401 ** 5402 ** <tr><td> 5th <td> const char* <td> Data type 5403 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5404 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5405 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5406 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5407 ** </table> 5408 ** </blockquote>)^ 5409 ** 5410 ** ^The memory pointed to by the character pointers returned for the 5411 ** declaration type and collation sequence is valid until the next 5412 ** call to any SQLite API function. 5413 ** 5414 ** ^If the specified table is actually a view, an [error code] is returned. 5415 ** 5416 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5417 ** is not a [WITHOUT ROWID] table and an 5418 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5419 ** parameters are set for the explicitly declared column. ^(If there is no 5420 ** [INTEGER PRIMARY KEY] column, then the outputs 5421 ** for the [rowid] are set as follows: 5422 ** 5423 ** <pre> 5424 ** data type: "INTEGER" 5425 ** collation sequence: "BINARY" 5426 ** not null: 0 5427 ** primary key: 1 5428 ** auto increment: 0 5429 ** </pre>)^ 5430 ** 5431 ** ^This function causes all database schemas to be read from disk and 5432 ** parsed, if that has not already been done, and returns an error if 5433 ** any errors are encountered while loading the schema. 5434 */ 5435 SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata( 5436 sqlite3 *db, /* Connection handle */ 5437 const char *zDbName, /* Database name or NULL */ 5438 const char *zTableName, /* Table name */ 5439 const char *zColumnName, /* Column name */ 5440 char const **pzDataType, /* OUTPUT: Declared data type */ 5441 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5442 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5443 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5444 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5445 ); 5446 5447 /* 5448 ** CAPI3REF: Load An Extension 5449 ** METHOD: sqlite3 5450 ** 5451 ** ^This interface loads an SQLite extension library from the named file. 5452 ** 5453 ** ^The sqlite3_load_extension() interface attempts to load an 5454 ** [SQLite extension] library contained in the file zFile. If 5455 ** the file cannot be loaded directly, attempts are made to load 5456 ** with various operating-system specific extensions added. 5457 ** So for example, if "samplelib" cannot be loaded, then names like 5458 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5459 ** be tried also. 5460 ** 5461 ** ^The entry point is zProc. 5462 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5463 ** entry point name on its own. It first tries "sqlite3_extension_init". 5464 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5465 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5466 ** characters in the filename from the last "/" to the first following 5467 ** "." and omitting any initial "lib".)^ 5468 ** ^The sqlite3_load_extension() interface returns 5469 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5470 ** ^If an error occurs and pzErrMsg is not 0, then the 5471 ** [sqlite3_load_extension()] interface shall attempt to 5472 ** fill *pzErrMsg with error message text stored in memory 5473 ** obtained from [sqlite3_malloc()]. The calling function 5474 ** should free this memory by calling [sqlite3_free()]. 5475 ** 5476 ** ^Extension loading must be enabled using 5477 ** [sqlite3_enable_load_extension()] prior to calling this API, 5478 ** otherwise an error will be returned. 5479 ** 5480 ** See also the [load_extension() SQL function]. 5481 */ 5482 SQLITE_API int SQLITE_STDCALL sqlite3_load_extension( 5483 sqlite3 *db, /* Load the extension into this database connection */ 5484 const char *zFile, /* Name of the shared library containing extension */ 5485 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5486 char **pzErrMsg /* Put error message here if not 0 */ 5487 ); 5488 5489 /* 5490 ** CAPI3REF: Enable Or Disable Extension Loading 5491 ** METHOD: sqlite3 5492 ** 5493 ** ^So as not to open security holes in older applications that are 5494 ** unprepared to deal with [extension loading], and as a means of disabling 5495 ** [extension loading] while evaluating user-entered SQL, the following API 5496 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5497 ** 5498 ** ^Extension loading is off by default. 5499 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5500 ** to turn extension loading on and call it with onoff==0 to turn 5501 ** it back off again. 5502 */ 5503 SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5504 5505 /* 5506 ** CAPI3REF: Automatically Load Statically Linked Extensions 5507 ** 5508 ** ^This interface causes the xEntryPoint() function to be invoked for 5509 ** each new [database connection] that is created. The idea here is that 5510 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5511 ** that is to be automatically loaded into all new database connections. 5512 ** 5513 ** ^(Even though the function prototype shows that xEntryPoint() takes 5514 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5515 ** arguments and expects and integer result as if the signature of the 5516 ** entry point where as follows: 5517 ** 5518 ** <blockquote><pre> 5519 ** int xEntryPoint( 5520 ** sqlite3 *db, 5521 ** const char **pzErrMsg, 5522 ** const struct sqlite3_api_routines *pThunk 5523 ** ); 5524 ** </pre></blockquote>)^ 5525 ** 5526 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5527 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5528 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5529 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5530 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5531 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5532 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5533 ** 5534 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5535 ** on the list of automatic extensions is a harmless no-op. ^No entry point 5536 ** will be called more than once for each database connection that is opened. 5537 ** 5538 ** See also: [sqlite3_reset_auto_extension()] 5539 ** and [sqlite3_cancel_auto_extension()] 5540 */ 5541 SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void)); 5542 5543 /* 5544 ** CAPI3REF: Cancel Automatic Extension Loading 5545 ** 5546 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5547 ** initialization routine X that was registered using a prior call to 5548 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5549 ** routine returns 1 if initialization routine X was successfully 5550 ** unregistered and it returns 0 if X was not on the list of initialization 5551 ** routines. 5552 */ 5553 SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5554 5555 /* 5556 ** CAPI3REF: Reset Automatic Extension Loading 5557 ** 5558 ** ^This interface disables all automatic extensions previously 5559 ** registered using [sqlite3_auto_extension()]. 5560 */ 5561 SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void); 5562 5563 /* 5564 ** The interface to the virtual-table mechanism is currently considered 5565 ** to be experimental. The interface might change in incompatible ways. 5566 ** If this is a problem for you, do not use the interface at this time. 5567 ** 5568 ** When the virtual-table mechanism stabilizes, we will declare the 5569 ** interface fixed, support it indefinitely, and remove this comment. 5570 */ 5571 5572 /* 5573 ** Structures used by the virtual table interface 5574 */ 5575 typedef struct sqlite3_vtab sqlite3_vtab; 5576 typedef struct sqlite3_index_info sqlite3_index_info; 5577 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5578 typedef struct sqlite3_module sqlite3_module; 5579 5580 /* 5581 ** CAPI3REF: Virtual Table Object 5582 ** KEYWORDS: sqlite3_module {virtual table module} 5583 ** 5584 ** This structure, sometimes called a "virtual table module", 5585 ** defines the implementation of a [virtual tables]. 5586 ** This structure consists mostly of methods for the module. 5587 ** 5588 ** ^A virtual table module is created by filling in a persistent 5589 ** instance of this structure and passing a pointer to that instance 5590 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5591 ** ^The registration remains valid until it is replaced by a different 5592 ** module or until the [database connection] closes. The content 5593 ** of this structure must not change while it is registered with 5594 ** any database connection. 5595 */ 5596 struct sqlite3_module { 5597 int iVersion; 5598 int (*xCreate)(sqlite3*, void *pAux, 5599 int argc, const char *const*argv, 5600 sqlite3_vtab **ppVTab, char**); 5601 int (*xConnect)(sqlite3*, void *pAux, 5602 int argc, const char *const*argv, 5603 sqlite3_vtab **ppVTab, char**); 5604 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5605 int (*xDisconnect)(sqlite3_vtab *pVTab); 5606 int (*xDestroy)(sqlite3_vtab *pVTab); 5607 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5608 int (*xClose)(sqlite3_vtab_cursor*); 5609 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5610 int argc, sqlite3_value **argv); 5611 int (*xNext)(sqlite3_vtab_cursor*); 5612 int (*xEof)(sqlite3_vtab_cursor*); 5613 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5614 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5615 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5616 int (*xBegin)(sqlite3_vtab *pVTab); 5617 int (*xSync)(sqlite3_vtab *pVTab); 5618 int (*xCommit)(sqlite3_vtab *pVTab); 5619 int (*xRollback)(sqlite3_vtab *pVTab); 5620 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5621 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5622 void **ppArg); 5623 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5624 /* The methods above are in version 1 of the sqlite_module object. Those 5625 ** below are for version 2 and greater. */ 5626 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5627 int (*xRelease)(sqlite3_vtab *pVTab, int); 5628 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5629 }; 5630 5631 /* 5632 ** CAPI3REF: Virtual Table Indexing Information 5633 ** KEYWORDS: sqlite3_index_info 5634 ** 5635 ** The sqlite3_index_info structure and its substructures is used as part 5636 ** of the [virtual table] interface to 5637 ** pass information into and receive the reply from the [xBestIndex] 5638 ** method of a [virtual table module]. The fields under **Inputs** are the 5639 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5640 ** results into the **Outputs** fields. 5641 ** 5642 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5643 ** 5644 ** <blockquote>column OP expr</blockquote> 5645 ** 5646 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5647 ** stored in aConstraint[].op using one of the 5648 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5649 ** ^(The index of the column is stored in 5650 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5651 ** expr on the right-hand side can be evaluated (and thus the constraint 5652 ** is usable) and false if it cannot.)^ 5653 ** 5654 ** ^The optimizer automatically inverts terms of the form "expr OP column" 5655 ** and makes other simplifications to the WHERE clause in an attempt to 5656 ** get as many WHERE clause terms into the form shown above as possible. 5657 ** ^The aConstraint[] array only reports WHERE clause terms that are 5658 ** relevant to the particular virtual table being queried. 5659 ** 5660 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5661 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5662 ** 5663 ** The colUsed field indicates which columns of the virtual table may be 5664 ** required by the current scan. Virtual table columns are numbered from 5665 ** zero in the order in which they appear within the CREATE TABLE statement 5666 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5667 ** the corresponding bit is set within the colUsed mask if the column may be 5668 ** required by SQLite. If the table has at least 64 columns and any column 5669 ** to the right of the first 63 is required, then bit 63 of colUsed is also 5670 ** set. In other words, column iCol may be required if the expression 5671 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5672 ** non-zero. 5673 ** 5674 ** The [xBestIndex] method must fill aConstraintUsage[] with information 5675 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5676 ** the right-hand side of the corresponding aConstraint[] is evaluated 5677 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5678 ** is true, then the constraint is assumed to be fully handled by the 5679 ** virtual table and is not checked again by SQLite.)^ 5680 ** 5681 ** ^The idxNum and idxPtr values are recorded and passed into the 5682 ** [xFilter] method. 5683 ** ^[sqlite3_free()] is used to free idxPtr if and only if 5684 ** needToFreeIdxPtr is true. 5685 ** 5686 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5687 ** the correct order to satisfy the ORDER BY clause so that no separate 5688 ** sorting step is required. 5689 ** 5690 ** ^The estimatedCost value is an estimate of the cost of a particular 5691 ** strategy. A cost of N indicates that the cost of the strategy is similar 5692 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 5693 ** indicates that the expense of the operation is similar to that of a 5694 ** binary search on a unique indexed field of an SQLite table with N rows. 5695 ** 5696 ** ^The estimatedRows value is an estimate of the number of rows that 5697 ** will be returned by the strategy. 5698 ** 5699 ** The xBestIndex method may optionally populate the idxFlags field with a 5700 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5701 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5702 ** assumes that the strategy may visit at most one row. 5703 ** 5704 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5705 ** SQLite also assumes that if a call to the xUpdate() method is made as 5706 ** part of the same statement to delete or update a virtual table row and the 5707 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5708 ** any database changes. In other words, if the xUpdate() returns 5709 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5710 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5711 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5712 ** the xUpdate method are automatically rolled back by SQLite. 5713 ** 5714 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5715 ** structure for SQLite version 3.8.2. If a virtual table extension is 5716 ** used with an SQLite version earlier than 3.8.2, the results of attempting 5717 ** to read or write the estimatedRows field are undefined (but are likely 5718 ** to included crashing the application). The estimatedRows field should 5719 ** therefore only be used if [sqlite3_libversion_number()] returns a 5720 ** value greater than or equal to 3008002. Similarly, the idxFlags field 5721 ** was added for version 3.9.0. It may therefore only be used if 5722 ** sqlite3_libversion_number() returns a value greater than or equal to 5723 ** 3009000. 5724 */ 5725 struct sqlite3_index_info { 5726 /* Inputs */ 5727 int nConstraint; /* Number of entries in aConstraint */ 5728 struct sqlite3_index_constraint { 5729 int iColumn; /* Column constrained. -1 for ROWID */ 5730 unsigned char op; /* Constraint operator */ 5731 unsigned char usable; /* True if this constraint is usable */ 5732 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5733 } *aConstraint; /* Table of WHERE clause constraints */ 5734 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5735 struct sqlite3_index_orderby { 5736 int iColumn; /* Column number */ 5737 unsigned char desc; /* True for DESC. False for ASC. */ 5738 } *aOrderBy; /* The ORDER BY clause */ 5739 /* Outputs */ 5740 struct sqlite3_index_constraint_usage { 5741 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5742 unsigned char omit; /* Do not code a test for this constraint */ 5743 } *aConstraintUsage; 5744 int idxNum; /* Number used to identify the index */ 5745 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5746 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5747 int orderByConsumed; /* True if output is already ordered */ 5748 double estimatedCost; /* Estimated cost of using this index */ 5749 /* Fields below are only available in SQLite 3.8.2 and later */ 5750 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5751 /* Fields below are only available in SQLite 3.9.0 and later */ 5752 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 5753 /* Fields below are only available in SQLite 3.10.0 and later */ 5754 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 5755 }; 5756 5757 /* 5758 ** CAPI3REF: Virtual Table Scan Flags 5759 */ 5760 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 5761 5762 /* 5763 ** CAPI3REF: Virtual Table Constraint Operator Codes 5764 ** 5765 ** These macros defined the allowed values for the 5766 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 5767 ** an operator that is part of a constraint term in the wHERE clause of 5768 ** a query that uses a [virtual table]. 5769 */ 5770 #define SQLITE_INDEX_CONSTRAINT_EQ 2 5771 #define SQLITE_INDEX_CONSTRAINT_GT 4 5772 #define SQLITE_INDEX_CONSTRAINT_LE 8 5773 #define SQLITE_INDEX_CONSTRAINT_LT 16 5774 #define SQLITE_INDEX_CONSTRAINT_GE 32 5775 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 5776 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 5777 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 5778 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 5779 5780 /* 5781 ** CAPI3REF: Register A Virtual Table Implementation 5782 ** METHOD: sqlite3 5783 ** 5784 ** ^These routines are used to register a new [virtual table module] name. 5785 ** ^Module names must be registered before 5786 ** creating a new [virtual table] using the module and before using a 5787 ** preexisting [virtual table] for the module. 5788 ** 5789 ** ^The module name is registered on the [database connection] specified 5790 ** by the first parameter. ^The name of the module is given by the 5791 ** second parameter. ^The third parameter is a pointer to 5792 ** the implementation of the [virtual table module]. ^The fourth 5793 ** parameter is an arbitrary client data pointer that is passed through 5794 ** into the [xCreate] and [xConnect] methods of the virtual table module 5795 ** when a new virtual table is be being created or reinitialized. 5796 ** 5797 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5798 ** is a pointer to a destructor for the pClientData. ^SQLite will 5799 ** invoke the destructor function (if it is not NULL) when SQLite 5800 ** no longer needs the pClientData pointer. ^The destructor will also 5801 ** be invoked if the call to sqlite3_create_module_v2() fails. 5802 ** ^The sqlite3_create_module() 5803 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 5804 ** destructor. 5805 */ 5806 SQLITE_API int SQLITE_STDCALL sqlite3_create_module( 5807 sqlite3 *db, /* SQLite connection to register module with */ 5808 const char *zName, /* Name of the module */ 5809 const sqlite3_module *p, /* Methods for the module */ 5810 void *pClientData /* Client data for xCreate/xConnect */ 5811 ); 5812 SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2( 5813 sqlite3 *db, /* SQLite connection to register module with */ 5814 const char *zName, /* Name of the module */ 5815 const sqlite3_module *p, /* Methods for the module */ 5816 void *pClientData, /* Client data for xCreate/xConnect */ 5817 void(*xDestroy)(void*) /* Module destructor function */ 5818 ); 5819 5820 /* 5821 ** CAPI3REF: Virtual Table Instance Object 5822 ** KEYWORDS: sqlite3_vtab 5823 ** 5824 ** Every [virtual table module] implementation uses a subclass 5825 ** of this object to describe a particular instance 5826 ** of the [virtual table]. Each subclass will 5827 ** be tailored to the specific needs of the module implementation. 5828 ** The purpose of this superclass is to define certain fields that are 5829 ** common to all module implementations. 5830 ** 5831 ** ^Virtual tables methods can set an error message by assigning a 5832 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5833 ** take care that any prior string is freed by a call to [sqlite3_free()] 5834 ** prior to assigning a new string to zErrMsg. ^After the error message 5835 ** is delivered up to the client application, the string will be automatically 5836 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5837 */ 5838 struct sqlite3_vtab { 5839 const sqlite3_module *pModule; /* The module for this virtual table */ 5840 int nRef; /* Number of open cursors */ 5841 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5842 /* Virtual table implementations will typically add additional fields */ 5843 }; 5844 5845 /* 5846 ** CAPI3REF: Virtual Table Cursor Object 5847 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5848 ** 5849 ** Every [virtual table module] implementation uses a subclass of the 5850 ** following structure to describe cursors that point into the 5851 ** [virtual table] and are used 5852 ** to loop through the virtual table. Cursors are created using the 5853 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5854 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5855 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5856 ** of the module. Each module implementation will define 5857 ** the content of a cursor structure to suit its own needs. 5858 ** 5859 ** This superclass exists in order to define fields of the cursor that 5860 ** are common to all implementations. 5861 */ 5862 struct sqlite3_vtab_cursor { 5863 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5864 /* Virtual table implementations will typically add additional fields */ 5865 }; 5866 5867 /* 5868 ** CAPI3REF: Declare The Schema Of A Virtual Table 5869 ** 5870 ** ^The [xCreate] and [xConnect] methods of a 5871 ** [virtual table module] call this interface 5872 ** to declare the format (the names and datatypes of the columns) of 5873 ** the virtual tables they implement. 5874 */ 5875 SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5876 5877 /* 5878 ** CAPI3REF: Overload A Function For A Virtual Table 5879 ** METHOD: sqlite3 5880 ** 5881 ** ^(Virtual tables can provide alternative implementations of functions 5882 ** using the [xFindFunction] method of the [virtual table module]. 5883 ** But global versions of those functions 5884 ** must exist in order to be overloaded.)^ 5885 ** 5886 ** ^(This API makes sure a global version of a function with a particular 5887 ** name and number of parameters exists. If no such function exists 5888 ** before this API is called, a new function is created.)^ ^The implementation 5889 ** of the new function always causes an exception to be thrown. So 5890 ** the new function is not good for anything by itself. Its only 5891 ** purpose is to be a placeholder function that can be overloaded 5892 ** by a [virtual table]. 5893 */ 5894 SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5895 5896 /* 5897 ** The interface to the virtual-table mechanism defined above (back up 5898 ** to a comment remarkably similar to this one) is currently considered 5899 ** to be experimental. The interface might change in incompatible ways. 5900 ** If this is a problem for you, do not use the interface at this time. 5901 ** 5902 ** When the virtual-table mechanism stabilizes, we will declare the 5903 ** interface fixed, support it indefinitely, and remove this comment. 5904 */ 5905 5906 /* 5907 ** CAPI3REF: A Handle To An Open BLOB 5908 ** KEYWORDS: {BLOB handle} {BLOB handles} 5909 ** 5910 ** An instance of this object represents an open BLOB on which 5911 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5912 ** ^Objects of this type are created by [sqlite3_blob_open()] 5913 ** and destroyed by [sqlite3_blob_close()]. 5914 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5915 ** can be used to read or write small subsections of the BLOB. 5916 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5917 */ 5918 typedef struct sqlite3_blob sqlite3_blob; 5919 5920 /* 5921 ** CAPI3REF: Open A BLOB For Incremental I/O 5922 ** METHOD: sqlite3 5923 ** CONSTRUCTOR: sqlite3_blob 5924 ** 5925 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5926 ** in row iRow, column zColumn, table zTable in database zDb; 5927 ** in other words, the same BLOB that would be selected by: 5928 ** 5929 ** <pre> 5930 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5931 ** </pre>)^ 5932 ** 5933 ** ^(Parameter zDb is not the filename that contains the database, but 5934 ** rather the symbolic name of the database. For attached databases, this is 5935 ** the name that appears after the AS keyword in the [ATTACH] statement. 5936 ** For the main database file, the database name is "main". For TEMP 5937 ** tables, the database name is "temp".)^ 5938 ** 5939 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 5940 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 5941 ** read-only access. 5942 ** 5943 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 5944 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 5945 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 5946 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 5947 ** on *ppBlob after this function it returns. 5948 ** 5949 ** This function fails with SQLITE_ERROR if any of the following are true: 5950 ** <ul> 5951 ** <li> ^(Database zDb does not exist)^, 5952 ** <li> ^(Table zTable does not exist within database zDb)^, 5953 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 5954 ** <li> ^(Column zColumn does not exist)^, 5955 ** <li> ^(Row iRow is not present in the table)^, 5956 ** <li> ^(The specified column of row iRow contains a value that is not 5957 ** a TEXT or BLOB value)^, 5958 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 5959 ** constraint and the blob is being opened for read/write access)^, 5960 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 5961 ** column zColumn is part of a [child key] definition and the blob is 5962 ** being opened for read/write access)^. 5963 ** </ul> 5964 ** 5965 ** ^Unless it returns SQLITE_MISUSE, this function sets the 5966 ** [database connection] error code and message accessible via 5967 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5968 ** 5969 ** 5970 ** ^(If the row that a BLOB handle points to is modified by an 5971 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5972 ** then the BLOB handle is marked as "expired". 5973 ** This is true if any column of the row is changed, even a column 5974 ** other than the one the BLOB handle is open on.)^ 5975 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5976 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5977 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 5978 ** rolled back by the expiration of the BLOB. Such changes will eventually 5979 ** commit if the transaction continues to completion.)^ 5980 ** 5981 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5982 ** the opened blob. ^The size of a blob may not be changed by this 5983 ** interface. Use the [UPDATE] SQL command to change the size of a 5984 ** blob. 5985 ** 5986 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5987 ** and the built-in [zeroblob] SQL function may be used to create a 5988 ** zero-filled blob to read or write using the incremental-blob interface. 5989 ** 5990 ** To avoid a resource leak, every open [BLOB handle] should eventually 5991 ** be released by a call to [sqlite3_blob_close()]. 5992 */ 5993 SQLITE_API int SQLITE_STDCALL sqlite3_blob_open( 5994 sqlite3*, 5995 const char *zDb, 5996 const char *zTable, 5997 const char *zColumn, 5998 sqlite3_int64 iRow, 5999 int flags, 6000 sqlite3_blob **ppBlob 6001 ); 6002 6003 /* 6004 ** CAPI3REF: Move a BLOB Handle to a New Row 6005 ** METHOD: sqlite3_blob 6006 ** 6007 ** ^This function is used to move an existing blob handle so that it points 6008 ** to a different row of the same database table. ^The new row is identified 6009 ** by the rowid value passed as the second argument. Only the row can be 6010 ** changed. ^The database, table and column on which the blob handle is open 6011 ** remain the same. Moving an existing blob handle to a new row can be 6012 ** faster than closing the existing handle and opening a new one. 6013 ** 6014 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6015 ** it must exist and there must be either a blob or text value stored in 6016 ** the nominated column.)^ ^If the new row is not present in the table, or if 6017 ** it does not contain a blob or text value, or if another error occurs, an 6018 ** SQLite error code is returned and the blob handle is considered aborted. 6019 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6020 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6021 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6022 ** always returns zero. 6023 ** 6024 ** ^This function sets the database handle error code and message. 6025 */ 6026 SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6027 6028 /* 6029 ** CAPI3REF: Close A BLOB Handle 6030 ** DESTRUCTOR: sqlite3_blob 6031 ** 6032 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6033 ** unconditionally. Even if this routine returns an error code, the 6034 ** handle is still closed.)^ 6035 ** 6036 ** ^If the blob handle being closed was opened for read-write access, and if 6037 ** the database is in auto-commit mode and there are no other open read-write 6038 ** blob handles or active write statements, the current transaction is 6039 ** committed. ^If an error occurs while committing the transaction, an error 6040 ** code is returned and the transaction rolled back. 6041 ** 6042 ** Calling this function with an argument that is not a NULL pointer or an 6043 ** open blob handle results in undefined behaviour. ^Calling this routine 6044 ** with a null pointer (such as would be returned by a failed call to 6045 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6046 ** is passed a valid open blob handle, the values returned by the 6047 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6048 */ 6049 SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *); 6050 6051 /* 6052 ** CAPI3REF: Return The Size Of An Open BLOB 6053 ** METHOD: sqlite3_blob 6054 ** 6055 ** ^Returns the size in bytes of the BLOB accessible via the 6056 ** successfully opened [BLOB handle] in its only argument. ^The 6057 ** incremental blob I/O routines can only read or overwriting existing 6058 ** blob content; they cannot change the size of a blob. 6059 ** 6060 ** This routine only works on a [BLOB handle] which has been created 6061 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6062 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6063 ** to this routine results in undefined and probably undesirable behavior. 6064 */ 6065 SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *); 6066 6067 /* 6068 ** CAPI3REF: Read Data From A BLOB Incrementally 6069 ** METHOD: sqlite3_blob 6070 ** 6071 ** ^(This function is used to read data from an open [BLOB handle] into a 6072 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6073 ** from the open BLOB, starting at offset iOffset.)^ 6074 ** 6075 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6076 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6077 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6078 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6079 ** can be determined using the [sqlite3_blob_bytes()] interface. 6080 ** 6081 ** ^An attempt to read from an expired [BLOB handle] fails with an 6082 ** error code of [SQLITE_ABORT]. 6083 ** 6084 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6085 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6086 ** 6087 ** This routine only works on a [BLOB handle] which has been created 6088 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6089 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6090 ** to this routine results in undefined and probably undesirable behavior. 6091 ** 6092 ** See also: [sqlite3_blob_write()]. 6093 */ 6094 SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6095 6096 /* 6097 ** CAPI3REF: Write Data Into A BLOB Incrementally 6098 ** METHOD: sqlite3_blob 6099 ** 6100 ** ^(This function is used to write data into an open [BLOB handle] from a 6101 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6102 ** into the open BLOB, starting at offset iOffset.)^ 6103 ** 6104 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6105 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6106 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6107 ** [database connection] error code and message accessible via 6108 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6109 ** 6110 ** ^If the [BLOB handle] passed as the first argument was not opened for 6111 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6112 ** this function returns [SQLITE_READONLY]. 6113 ** 6114 ** This function may only modify the contents of the BLOB; it is 6115 ** not possible to increase the size of a BLOB using this API. 6116 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6117 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6118 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6119 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6120 ** than zero [SQLITE_ERROR] is returned and no data is written. 6121 ** 6122 ** ^An attempt to write to an expired [BLOB handle] fails with an 6123 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6124 ** before the [BLOB handle] expired are not rolled back by the 6125 ** expiration of the handle, though of course those changes might 6126 ** have been overwritten by the statement that expired the BLOB handle 6127 ** or by other independent statements. 6128 ** 6129 ** This routine only works on a [BLOB handle] which has been created 6130 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6131 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6132 ** to this routine results in undefined and probably undesirable behavior. 6133 ** 6134 ** See also: [sqlite3_blob_read()]. 6135 */ 6136 SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6137 6138 /* 6139 ** CAPI3REF: Virtual File System Objects 6140 ** 6141 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6142 ** that SQLite uses to interact 6143 ** with the underlying operating system. Most SQLite builds come with a 6144 ** single default VFS that is appropriate for the host computer. 6145 ** New VFSes can be registered and existing VFSes can be unregistered. 6146 ** The following interfaces are provided. 6147 ** 6148 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6149 ** ^Names are case sensitive. 6150 ** ^Names are zero-terminated UTF-8 strings. 6151 ** ^If there is no match, a NULL pointer is returned. 6152 ** ^If zVfsName is NULL then the default VFS is returned. 6153 ** 6154 ** ^New VFSes are registered with sqlite3_vfs_register(). 6155 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6156 ** ^The same VFS can be registered multiple times without injury. 6157 ** ^To make an existing VFS into the default VFS, register it again 6158 ** with the makeDflt flag set. If two different VFSes with the 6159 ** same name are registered, the behavior is undefined. If a 6160 ** VFS is registered with a name that is NULL or an empty string, 6161 ** then the behavior is undefined. 6162 ** 6163 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6164 ** ^(If the default VFS is unregistered, another VFS is chosen as 6165 ** the default. The choice for the new VFS is arbitrary.)^ 6166 */ 6167 SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName); 6168 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6169 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*); 6170 6171 /* 6172 ** CAPI3REF: Mutexes 6173 ** 6174 ** The SQLite core uses these routines for thread 6175 ** synchronization. Though they are intended for internal 6176 ** use by SQLite, code that links against SQLite is 6177 ** permitted to use any of these routines. 6178 ** 6179 ** The SQLite source code contains multiple implementations 6180 ** of these mutex routines. An appropriate implementation 6181 ** is selected automatically at compile-time. The following 6182 ** implementations are available in the SQLite core: 6183 ** 6184 ** <ul> 6185 ** <li> SQLITE_MUTEX_PTHREADS 6186 ** <li> SQLITE_MUTEX_W32 6187 ** <li> SQLITE_MUTEX_NOOP 6188 ** </ul> 6189 ** 6190 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6191 ** that does no real locking and is appropriate for use in 6192 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6193 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6194 ** and Windows. 6195 ** 6196 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6197 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6198 ** implementation is included with the library. In this case the 6199 ** application must supply a custom mutex implementation using the 6200 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6201 ** before calling sqlite3_initialize() or any other public sqlite3_ 6202 ** function that calls sqlite3_initialize(). 6203 ** 6204 ** ^The sqlite3_mutex_alloc() routine allocates a new 6205 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6206 ** routine returns NULL if it is unable to allocate the requested 6207 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6208 ** integer constants: 6209 ** 6210 ** <ul> 6211 ** <li> SQLITE_MUTEX_FAST 6212 ** <li> SQLITE_MUTEX_RECURSIVE 6213 ** <li> SQLITE_MUTEX_STATIC_MASTER 6214 ** <li> SQLITE_MUTEX_STATIC_MEM 6215 ** <li> SQLITE_MUTEX_STATIC_OPEN 6216 ** <li> SQLITE_MUTEX_STATIC_PRNG 6217 ** <li> SQLITE_MUTEX_STATIC_LRU 6218 ** <li> SQLITE_MUTEX_STATIC_PMEM 6219 ** <li> SQLITE_MUTEX_STATIC_APP1 6220 ** <li> SQLITE_MUTEX_STATIC_APP2 6221 ** <li> SQLITE_MUTEX_STATIC_APP3 6222 ** <li> SQLITE_MUTEX_STATIC_VFS1 6223 ** <li> SQLITE_MUTEX_STATIC_VFS2 6224 ** <li> SQLITE_MUTEX_STATIC_VFS3 6225 ** </ul> 6226 ** 6227 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6228 ** cause sqlite3_mutex_alloc() to create 6229 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6230 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6231 ** The mutex implementation does not need to make a distinction 6232 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6233 ** not want to. SQLite will only request a recursive mutex in 6234 ** cases where it really needs one. If a faster non-recursive mutex 6235 ** implementation is available on the host platform, the mutex subsystem 6236 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6237 ** 6238 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6239 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6240 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6241 ** used by the current version of SQLite. Future versions of SQLite 6242 ** may add additional static mutexes. Static mutexes are for internal 6243 ** use by SQLite only. Applications that use SQLite mutexes should 6244 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6245 ** SQLITE_MUTEX_RECURSIVE. 6246 ** 6247 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6248 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6249 ** returns a different mutex on every call. ^For the static 6250 ** mutex types, the same mutex is returned on every call that has 6251 ** the same type number. 6252 ** 6253 ** ^The sqlite3_mutex_free() routine deallocates a previously 6254 ** allocated dynamic mutex. Attempting to deallocate a static 6255 ** mutex results in undefined behavior. 6256 ** 6257 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6258 ** to enter a mutex. ^If another thread is already within the mutex, 6259 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6260 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6261 ** upon successful entry. ^(Mutexes created using 6262 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6263 ** In such cases, the 6264 ** mutex must be exited an equal number of times before another thread 6265 ** can enter.)^ If the same thread tries to enter any mutex other 6266 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6267 ** 6268 ** ^(Some systems (for example, Windows 95) do not support the operation 6269 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6270 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6271 ** sqlite3_mutex_try() as an optimization so this is acceptable 6272 ** behavior.)^ 6273 ** 6274 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6275 ** previously entered by the same thread. The behavior 6276 ** is undefined if the mutex is not currently entered by the 6277 ** calling thread or is not currently allocated. 6278 ** 6279 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6280 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6281 ** behave as no-ops. 6282 ** 6283 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6284 */ 6285 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int); 6286 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*); 6287 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*); 6288 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*); 6289 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*); 6290 6291 /* 6292 ** CAPI3REF: Mutex Methods Object 6293 ** 6294 ** An instance of this structure defines the low-level routines 6295 ** used to allocate and use mutexes. 6296 ** 6297 ** Usually, the default mutex implementations provided by SQLite are 6298 ** sufficient, however the application has the option of substituting a custom 6299 ** implementation for specialized deployments or systems for which SQLite 6300 ** does not provide a suitable implementation. In this case, the application 6301 ** creates and populates an instance of this structure to pass 6302 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6303 ** Additionally, an instance of this structure can be used as an 6304 ** output variable when querying the system for the current mutex 6305 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6306 ** 6307 ** ^The xMutexInit method defined by this structure is invoked as 6308 ** part of system initialization by the sqlite3_initialize() function. 6309 ** ^The xMutexInit routine is called by SQLite exactly once for each 6310 ** effective call to [sqlite3_initialize()]. 6311 ** 6312 ** ^The xMutexEnd method defined by this structure is invoked as 6313 ** part of system shutdown by the sqlite3_shutdown() function. The 6314 ** implementation of this method is expected to release all outstanding 6315 ** resources obtained by the mutex methods implementation, especially 6316 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6317 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6318 ** 6319 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6320 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6321 ** xMutexNotheld) implement the following interfaces (respectively): 6322 ** 6323 ** <ul> 6324 ** <li> [sqlite3_mutex_alloc()] </li> 6325 ** <li> [sqlite3_mutex_free()] </li> 6326 ** <li> [sqlite3_mutex_enter()] </li> 6327 ** <li> [sqlite3_mutex_try()] </li> 6328 ** <li> [sqlite3_mutex_leave()] </li> 6329 ** <li> [sqlite3_mutex_held()] </li> 6330 ** <li> [sqlite3_mutex_notheld()] </li> 6331 ** </ul>)^ 6332 ** 6333 ** The only difference is that the public sqlite3_XXX functions enumerated 6334 ** above silently ignore any invocations that pass a NULL pointer instead 6335 ** of a valid mutex handle. The implementations of the methods defined 6336 ** by this structure are not required to handle this case, the results 6337 ** of passing a NULL pointer instead of a valid mutex handle are undefined 6338 ** (i.e. it is acceptable to provide an implementation that segfaults if 6339 ** it is passed a NULL pointer). 6340 ** 6341 ** The xMutexInit() method must be threadsafe. It must be harmless to 6342 ** invoke xMutexInit() multiple times within the same process and without 6343 ** intervening calls to xMutexEnd(). Second and subsequent calls to 6344 ** xMutexInit() must be no-ops. 6345 ** 6346 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6347 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6348 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6349 ** memory allocation for a fast or recursive mutex. 6350 ** 6351 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6352 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6353 ** If xMutexInit fails in any way, it is expected to clean up after itself 6354 ** prior to returning. 6355 */ 6356 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6357 struct sqlite3_mutex_methods { 6358 int (*xMutexInit)(void); 6359 int (*xMutexEnd)(void); 6360 sqlite3_mutex *(*xMutexAlloc)(int); 6361 void (*xMutexFree)(sqlite3_mutex *); 6362 void (*xMutexEnter)(sqlite3_mutex *); 6363 int (*xMutexTry)(sqlite3_mutex *); 6364 void (*xMutexLeave)(sqlite3_mutex *); 6365 int (*xMutexHeld)(sqlite3_mutex *); 6366 int (*xMutexNotheld)(sqlite3_mutex *); 6367 }; 6368 6369 /* 6370 ** CAPI3REF: Mutex Verification Routines 6371 ** 6372 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6373 ** are intended for use inside assert() statements. The SQLite core 6374 ** never uses these routines except inside an assert() and applications 6375 ** are advised to follow the lead of the core. The SQLite core only 6376 ** provides implementations for these routines when it is compiled 6377 ** with the SQLITE_DEBUG flag. External mutex implementations 6378 ** are only required to provide these routines if SQLITE_DEBUG is 6379 ** defined and if NDEBUG is not defined. 6380 ** 6381 ** These routines should return true if the mutex in their argument 6382 ** is held or not held, respectively, by the calling thread. 6383 ** 6384 ** The implementation is not required to provide versions of these 6385 ** routines that actually work. If the implementation does not provide working 6386 ** versions of these routines, it should at least provide stubs that always 6387 ** return true so that one does not get spurious assertion failures. 6388 ** 6389 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6390 ** the routine should return 1. This seems counter-intuitive since 6391 ** clearly the mutex cannot be held if it does not exist. But 6392 ** the reason the mutex does not exist is because the build is not 6393 ** using mutexes. And we do not want the assert() containing the 6394 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6395 ** the appropriate thing to do. The sqlite3_mutex_notheld() 6396 ** interface should also return 1 when given a NULL pointer. 6397 */ 6398 #ifndef NDEBUG 6399 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*); 6400 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*); 6401 #endif 6402 6403 /* 6404 ** CAPI3REF: Mutex Types 6405 ** 6406 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6407 ** which is one of these integer constants. 6408 ** 6409 ** The set of static mutexes may change from one SQLite release to the 6410 ** next. Applications that override the built-in mutex logic must be 6411 ** prepared to accommodate additional static mutexes. 6412 */ 6413 #define SQLITE_MUTEX_FAST 0 6414 #define SQLITE_MUTEX_RECURSIVE 1 6415 #define SQLITE_MUTEX_STATIC_MASTER 2 6416 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6417 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6418 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6419 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6420 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6421 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6422 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6423 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6424 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6425 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6426 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6427 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6428 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6429 6430 /* 6431 ** CAPI3REF: Retrieve the mutex for a database connection 6432 ** METHOD: sqlite3 6433 ** 6434 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6435 ** serializes access to the [database connection] given in the argument 6436 ** when the [threading mode] is Serialized. 6437 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6438 ** routine returns a NULL pointer. 6439 */ 6440 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*); 6441 6442 /* 6443 ** CAPI3REF: Low-Level Control Of Database Files 6444 ** METHOD: sqlite3 6445 ** 6446 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6447 ** xFileControl method for the [sqlite3_io_methods] object associated 6448 ** with a particular database identified by the second argument. ^The 6449 ** name of the database is "main" for the main database or "temp" for the 6450 ** TEMP database, or the name that appears after the AS keyword for 6451 ** databases that are added using the [ATTACH] SQL command. 6452 ** ^A NULL pointer can be used in place of "main" to refer to the 6453 ** main database file. 6454 ** ^The third and fourth parameters to this routine 6455 ** are passed directly through to the second and third parameters of 6456 ** the xFileControl method. ^The return value of the xFileControl 6457 ** method becomes the return value of this routine. 6458 ** 6459 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6460 ** a pointer to the underlying [sqlite3_file] object to be written into 6461 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6462 ** case is a short-circuit path which does not actually invoke the 6463 ** underlying sqlite3_io_methods.xFileControl method. 6464 ** 6465 ** ^If the second parameter (zDbName) does not match the name of any 6466 ** open database file, then SQLITE_ERROR is returned. ^This error 6467 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6468 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6469 ** also return SQLITE_ERROR. There is no way to distinguish between 6470 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6471 ** xFileControl method. 6472 ** 6473 ** See also: [SQLITE_FCNTL_LOCKSTATE] 6474 */ 6475 SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6476 6477 /* 6478 ** CAPI3REF: Testing Interface 6479 ** 6480 ** ^The sqlite3_test_control() interface is used to read out internal 6481 ** state of SQLite and to inject faults into SQLite for testing 6482 ** purposes. ^The first parameter is an operation code that determines 6483 ** the number, meaning, and operation of all subsequent parameters. 6484 ** 6485 ** This interface is not for use by applications. It exists solely 6486 ** for verifying the correct operation of the SQLite library. Depending 6487 ** on how the SQLite library is compiled, this interface might not exist. 6488 ** 6489 ** The details of the operation codes, their meanings, the parameters 6490 ** they take, and what they do are all subject to change without notice. 6491 ** Unlike most of the SQLite API, this function is not guaranteed to 6492 ** operate consistently from one release to the next. 6493 */ 6494 SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...); 6495 6496 /* 6497 ** CAPI3REF: Testing Interface Operation Codes 6498 ** 6499 ** These constants are the valid operation code parameters used 6500 ** as the first argument to [sqlite3_test_control()]. 6501 ** 6502 ** These parameters and their meanings are subject to change 6503 ** without notice. These values are for testing purposes only. 6504 ** Applications should not use any of these parameters or the 6505 ** [sqlite3_test_control()] interface. 6506 */ 6507 #define SQLITE_TESTCTRL_FIRST 5 6508 #define SQLITE_TESTCTRL_PRNG_SAVE 5 6509 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6510 #define SQLITE_TESTCTRL_PRNG_RESET 7 6511 #define SQLITE_TESTCTRL_BITVEC_TEST 8 6512 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6513 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6514 #define SQLITE_TESTCTRL_PENDING_BYTE 11 6515 #define SQLITE_TESTCTRL_ASSERT 12 6516 #define SQLITE_TESTCTRL_ALWAYS 13 6517 #define SQLITE_TESTCTRL_RESERVE 14 6518 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6519 #define SQLITE_TESTCTRL_ISKEYWORD 16 6520 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6521 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6522 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6523 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6524 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6525 #define SQLITE_TESTCTRL_BYTEORDER 22 6526 #define SQLITE_TESTCTRL_ISINIT 23 6527 #define SQLITE_TESTCTRL_SORTER_MMAP 24 6528 #define SQLITE_TESTCTRL_IMPOSTER 25 6529 #define SQLITE_TESTCTRL_LAST 25 6530 6531 /* 6532 ** CAPI3REF: SQLite Runtime Status 6533 ** 6534 ** ^These interfaces are used to retrieve runtime status information 6535 ** about the performance of SQLite, and optionally to reset various 6536 ** highwater marks. ^The first argument is an integer code for 6537 ** the specific parameter to measure. ^(Recognized integer codes 6538 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 6539 ** ^The current value of the parameter is returned into *pCurrent. 6540 ** ^The highest recorded value is returned in *pHighwater. ^If the 6541 ** resetFlag is true, then the highest record value is reset after 6542 ** *pHighwater is written. ^(Some parameters do not record the highest 6543 ** value. For those parameters 6544 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6545 ** ^(Other parameters record only the highwater mark and not the current 6546 ** value. For these latter parameters nothing is written into *pCurrent.)^ 6547 ** 6548 ** ^The sqlite3_status() and sqlite3_status64() routines return 6549 ** SQLITE_OK on success and a non-zero [error code] on failure. 6550 ** 6551 ** If either the current value or the highwater mark is too large to 6552 ** be represented by a 32-bit integer, then the values returned by 6553 ** sqlite3_status() are undefined. 6554 ** 6555 ** See also: [sqlite3_db_status()] 6556 */ 6557 SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6558 SQLITE_API int SQLITE_STDCALL sqlite3_status64( 6559 int op, 6560 sqlite3_int64 *pCurrent, 6561 sqlite3_int64 *pHighwater, 6562 int resetFlag 6563 ); 6564 6565 6566 /* 6567 ** CAPI3REF: Status Parameters 6568 ** KEYWORDS: {status parameters} 6569 ** 6570 ** These integer constants designate various run-time status parameters 6571 ** that can be returned by [sqlite3_status()]. 6572 ** 6573 ** <dl> 6574 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6575 ** <dd>This parameter is the current amount of memory checked out 6576 ** using [sqlite3_malloc()], either directly or indirectly. The 6577 ** figure includes calls made to [sqlite3_malloc()] by the application 6578 ** and internal memory usage by the SQLite library. Scratch memory 6579 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6580 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6581 ** this parameter. The amount returned is the sum of the allocation 6582 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6583 ** 6584 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6585 ** <dd>This parameter records the largest memory allocation request 6586 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6587 ** internal equivalents). Only the value returned in the 6588 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6589 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6590 ** 6591 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6592 ** <dd>This parameter records the number of separate memory allocations 6593 ** currently checked out.</dd>)^ 6594 ** 6595 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6596 ** <dd>This parameter returns the number of pages used out of the 6597 ** [pagecache memory allocator] that was configured using 6598 ** [SQLITE_CONFIG_PAGECACHE]. The 6599 ** value returned is in pages, not in bytes.</dd>)^ 6600 ** 6601 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6602 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6603 ** <dd>This parameter returns the number of bytes of page cache 6604 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6605 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6606 ** returned value includes allocations that overflowed because they 6607 ** where too large (they were larger than the "sz" parameter to 6608 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6609 ** no space was left in the page cache.</dd>)^ 6610 ** 6611 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6612 ** <dd>This parameter records the largest memory allocation request 6613 ** handed to [pagecache memory allocator]. Only the value returned in the 6614 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6615 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6616 ** 6617 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6618 ** <dd>This parameter returns the number of allocations used out of the 6619 ** [scratch memory allocator] configured using 6620 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6621 ** in bytes. Since a single thread may only have one scratch allocation 6622 ** outstanding at time, this parameter also reports the number of threads 6623 ** using scratch memory at the same time.</dd>)^ 6624 ** 6625 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6626 ** <dd>This parameter returns the number of bytes of scratch memory 6627 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6628 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6629 ** returned include overflows because the requested allocation was too 6630 ** larger (that is, because the requested allocation was larger than the 6631 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6632 ** slots were available. 6633 ** </dd>)^ 6634 ** 6635 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6636 ** <dd>This parameter records the largest memory allocation request 6637 ** handed to [scratch memory allocator]. Only the value returned in the 6638 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6639 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6640 ** 6641 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6642 ** <dd>The *pHighwater parameter records the deepest parser stack. 6643 ** The *pCurrent value is undefined. The *pHighwater value is only 6644 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6645 ** </dl> 6646 ** 6647 ** New status parameters may be added from time to time. 6648 */ 6649 #define SQLITE_STATUS_MEMORY_USED 0 6650 #define SQLITE_STATUS_PAGECACHE_USED 1 6651 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6652 #define SQLITE_STATUS_SCRATCH_USED 3 6653 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6654 #define SQLITE_STATUS_MALLOC_SIZE 5 6655 #define SQLITE_STATUS_PARSER_STACK 6 6656 #define SQLITE_STATUS_PAGECACHE_SIZE 7 6657 #define SQLITE_STATUS_SCRATCH_SIZE 8 6658 #define SQLITE_STATUS_MALLOC_COUNT 9 6659 6660 /* 6661 ** CAPI3REF: Database Connection Status 6662 ** METHOD: sqlite3 6663 ** 6664 ** ^This interface is used to retrieve runtime status information 6665 ** about a single [database connection]. ^The first argument is the 6666 ** database connection object to be interrogated. ^The second argument 6667 ** is an integer constant, taken from the set of 6668 ** [SQLITE_DBSTATUS options], that 6669 ** determines the parameter to interrogate. The set of 6670 ** [SQLITE_DBSTATUS options] is likely 6671 ** to grow in future releases of SQLite. 6672 ** 6673 ** ^The current value of the requested parameter is written into *pCur 6674 ** and the highest instantaneous value is written into *pHiwtr. ^If 6675 ** the resetFlg is true, then the highest instantaneous value is 6676 ** reset back down to the current value. 6677 ** 6678 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6679 ** non-zero [error code] on failure. 6680 ** 6681 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6682 */ 6683 SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6684 6685 /* 6686 ** CAPI3REF: Status Parameters for database connections 6687 ** KEYWORDS: {SQLITE_DBSTATUS options} 6688 ** 6689 ** These constants are the available integer "verbs" that can be passed as 6690 ** the second argument to the [sqlite3_db_status()] interface. 6691 ** 6692 ** New verbs may be added in future releases of SQLite. Existing verbs 6693 ** might be discontinued. Applications should check the return code from 6694 ** [sqlite3_db_status()] to make sure that the call worked. 6695 ** The [sqlite3_db_status()] interface will return a non-zero error code 6696 ** if a discontinued or unsupported verb is invoked. 6697 ** 6698 ** <dl> 6699 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6700 ** <dd>This parameter returns the number of lookaside memory slots currently 6701 ** checked out.</dd>)^ 6702 ** 6703 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6704 ** <dd>This parameter returns the number malloc attempts that were 6705 ** satisfied using lookaside memory. Only the high-water value is meaningful; 6706 ** the current value is always zero.)^ 6707 ** 6708 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6709 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6710 ** <dd>This parameter returns the number malloc attempts that might have 6711 ** been satisfied using lookaside memory but failed due to the amount of 6712 ** memory requested being larger than the lookaside slot size. 6713 ** Only the high-water value is meaningful; 6714 ** the current value is always zero.)^ 6715 ** 6716 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6717 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6718 ** <dd>This parameter returns the number malloc attempts that might have 6719 ** been satisfied using lookaside memory but failed due to all lookaside 6720 ** memory already being in use. 6721 ** Only the high-water value is meaningful; 6722 ** the current value is always zero.)^ 6723 ** 6724 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6725 ** <dd>This parameter returns the approximate number of bytes of heap 6726 ** memory used by all pager caches associated with the database connection.)^ 6727 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6728 ** 6729 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6730 ** <dd>This parameter returns the approximate number of bytes of heap 6731 ** memory used to store the schema for all databases associated 6732 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6733 ** ^The full amount of memory used by the schemas is reported, even if the 6734 ** schema memory is shared with other database connections due to 6735 ** [shared cache mode] being enabled. 6736 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6737 ** 6738 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6739 ** <dd>This parameter returns the approximate number of bytes of heap 6740 ** and lookaside memory used by all prepared statements associated with 6741 ** the database connection.)^ 6742 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6743 ** </dd> 6744 ** 6745 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6746 ** <dd>This parameter returns the number of pager cache hits that have 6747 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6748 ** is always 0. 6749 ** </dd> 6750 ** 6751 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6752 ** <dd>This parameter returns the number of pager cache misses that have 6753 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6754 ** is always 0. 6755 ** </dd> 6756 ** 6757 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6758 ** <dd>This parameter returns the number of dirty cache entries that have 6759 ** been written to disk. Specifically, the number of pages written to the 6760 ** wal file in wal mode databases, or the number of pages written to the 6761 ** database file in rollback mode databases. Any pages written as part of 6762 ** transaction rollback or database recovery operations are not included. 6763 ** If an IO or other error occurs while writing a page to disk, the effect 6764 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6765 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6766 ** </dd> 6767 ** 6768 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6769 ** <dd>This parameter returns zero for the current value if and only if 6770 ** all foreign key constraints (deferred or immediate) have been 6771 ** resolved.)^ ^The highwater mark is always 0. 6772 ** </dd> 6773 ** </dl> 6774 */ 6775 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6776 #define SQLITE_DBSTATUS_CACHE_USED 1 6777 #define SQLITE_DBSTATUS_SCHEMA_USED 2 6778 #define SQLITE_DBSTATUS_STMT_USED 3 6779 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6780 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6781 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6782 #define SQLITE_DBSTATUS_CACHE_HIT 7 6783 #define SQLITE_DBSTATUS_CACHE_MISS 8 6784 #define SQLITE_DBSTATUS_CACHE_WRITE 9 6785 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 6786 #define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6787 6788 6789 /* 6790 ** CAPI3REF: Prepared Statement Status 6791 ** METHOD: sqlite3_stmt 6792 ** 6793 ** ^(Each prepared statement maintains various 6794 ** [SQLITE_STMTSTATUS counters] that measure the number 6795 ** of times it has performed specific operations.)^ These counters can 6796 ** be used to monitor the performance characteristics of the prepared 6797 ** statements. For example, if the number of table steps greatly exceeds 6798 ** the number of table searches or result rows, that would tend to indicate 6799 ** that the prepared statement is using a full table scan rather than 6800 ** an index. 6801 ** 6802 ** ^(This interface is used to retrieve and reset counter values from 6803 ** a [prepared statement]. The first argument is the prepared statement 6804 ** object to be interrogated. The second argument 6805 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6806 ** to be interrogated.)^ 6807 ** ^The current value of the requested counter is returned. 6808 ** ^If the resetFlg is true, then the counter is reset to zero after this 6809 ** interface call returns. 6810 ** 6811 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6812 */ 6813 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6814 6815 /* 6816 ** CAPI3REF: Status Parameters for prepared statements 6817 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6818 ** 6819 ** These preprocessor macros define integer codes that name counter 6820 ** values associated with the [sqlite3_stmt_status()] interface. 6821 ** The meanings of the various counters are as follows: 6822 ** 6823 ** <dl> 6824 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6825 ** <dd>^This is the number of times that SQLite has stepped forward in 6826 ** a table as part of a full table scan. Large numbers for this counter 6827 ** may indicate opportunities for performance improvement through 6828 ** careful use of indices.</dd> 6829 ** 6830 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6831 ** <dd>^This is the number of sort operations that have occurred. 6832 ** A non-zero value in this counter may indicate an opportunity to 6833 ** improvement performance through careful use of indices.</dd> 6834 ** 6835 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6836 ** <dd>^This is the number of rows inserted into transient indices that 6837 ** were created automatically in order to help joins run faster. 6838 ** A non-zero value in this counter may indicate an opportunity to 6839 ** improvement performance by adding permanent indices that do not 6840 ** need to be reinitialized each time the statement is run.</dd> 6841 ** 6842 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6843 ** <dd>^This is the number of virtual machine operations executed 6844 ** by the prepared statement if that number is less than or equal 6845 ** to 2147483647. The number of virtual machine operations can be 6846 ** used as a proxy for the total work done by the prepared statement. 6847 ** If the number of virtual machine operations exceeds 2147483647 6848 ** then the value returned by this statement status code is undefined. 6849 ** </dd> 6850 ** </dl> 6851 */ 6852 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6853 #define SQLITE_STMTSTATUS_SORT 2 6854 #define SQLITE_STMTSTATUS_AUTOINDEX 3 6855 #define SQLITE_STMTSTATUS_VM_STEP 4 6856 6857 /* 6858 ** CAPI3REF: Custom Page Cache Object 6859 ** 6860 ** The sqlite3_pcache type is opaque. It is implemented by 6861 ** the pluggable module. The SQLite core has no knowledge of 6862 ** its size or internal structure and never deals with the 6863 ** sqlite3_pcache object except by holding and passing pointers 6864 ** to the object. 6865 ** 6866 ** See [sqlite3_pcache_methods2] for additional information. 6867 */ 6868 typedef struct sqlite3_pcache sqlite3_pcache; 6869 6870 /* 6871 ** CAPI3REF: Custom Page Cache Object 6872 ** 6873 ** The sqlite3_pcache_page object represents a single page in the 6874 ** page cache. The page cache will allocate instances of this 6875 ** object. Various methods of the page cache use pointers to instances 6876 ** of this object as parameters or as their return value. 6877 ** 6878 ** See [sqlite3_pcache_methods2] for additional information. 6879 */ 6880 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6881 struct sqlite3_pcache_page { 6882 void *pBuf; /* The content of the page */ 6883 void *pExtra; /* Extra information associated with the page */ 6884 }; 6885 6886 /* 6887 ** CAPI3REF: Application Defined Page Cache. 6888 ** KEYWORDS: {page cache} 6889 ** 6890 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6891 ** register an alternative page cache implementation by passing in an 6892 ** instance of the sqlite3_pcache_methods2 structure.)^ 6893 ** In many applications, most of the heap memory allocated by 6894 ** SQLite is used for the page cache. 6895 ** By implementing a 6896 ** custom page cache using this API, an application can better control 6897 ** the amount of memory consumed by SQLite, the way in which 6898 ** that memory is allocated and released, and the policies used to 6899 ** determine exactly which parts of a database file are cached and for 6900 ** how long. 6901 ** 6902 ** The alternative page cache mechanism is an 6903 ** extreme measure that is only needed by the most demanding applications. 6904 ** The built-in page cache is recommended for most uses. 6905 ** 6906 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6907 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6908 ** the application may discard the parameter after the call to 6909 ** [sqlite3_config()] returns.)^ 6910 ** 6911 ** [[the xInit() page cache method]] 6912 ** ^(The xInit() method is called once for each effective 6913 ** call to [sqlite3_initialize()])^ 6914 ** (usually only once during the lifetime of the process). ^(The xInit() 6915 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6916 ** The intent of the xInit() method is to set up global data structures 6917 ** required by the custom page cache implementation. 6918 ** ^(If the xInit() method is NULL, then the 6919 ** built-in default page cache is used instead of the application defined 6920 ** page cache.)^ 6921 ** 6922 ** [[the xShutdown() page cache method]] 6923 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6924 ** It can be used to clean up 6925 ** any outstanding resources before process shutdown, if required. 6926 ** ^The xShutdown() method may be NULL. 6927 ** 6928 ** ^SQLite automatically serializes calls to the xInit method, 6929 ** so the xInit method need not be threadsafe. ^The 6930 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 6931 ** not need to be threadsafe either. All other methods must be threadsafe 6932 ** in multithreaded applications. 6933 ** 6934 ** ^SQLite will never invoke xInit() more than once without an intervening 6935 ** call to xShutdown(). 6936 ** 6937 ** [[the xCreate() page cache methods]] 6938 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 6939 ** SQLite will typically create one cache instance for each open database file, 6940 ** though this is not guaranteed. ^The 6941 ** first parameter, szPage, is the size in bytes of the pages that must 6942 ** be allocated by the cache. ^szPage will always a power of two. ^The 6943 ** second parameter szExtra is a number of bytes of extra storage 6944 ** associated with each page cache entry. ^The szExtra parameter will 6945 ** a number less than 250. SQLite will use the 6946 ** extra szExtra bytes on each page to store metadata about the underlying 6947 ** database page on disk. The value passed into szExtra depends 6948 ** on the SQLite version, the target platform, and how SQLite was compiled. 6949 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6950 ** created will be used to cache database pages of a file stored on disk, or 6951 ** false if it is used for an in-memory database. The cache implementation 6952 ** does not have to do anything special based with the value of bPurgeable; 6953 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6954 ** never invoke xUnpin() except to deliberately delete a page. 6955 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6956 ** false will always have the "discard" flag set to true. 6957 ** ^Hence, a cache created with bPurgeable false will 6958 ** never contain any unpinned pages. 6959 ** 6960 ** [[the xCachesize() page cache method]] 6961 ** ^(The xCachesize() method may be called at any time by SQLite to set the 6962 ** suggested maximum cache-size (number of pages stored by) the cache 6963 ** instance passed as the first argument. This is the value configured using 6964 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6965 ** parameter, the implementation is not required to do anything with this 6966 ** value; it is advisory only. 6967 ** 6968 ** [[the xPagecount() page cache methods]] 6969 ** The xPagecount() method must return the number of pages currently 6970 ** stored in the cache, both pinned and unpinned. 6971 ** 6972 ** [[the xFetch() page cache methods]] 6973 ** The xFetch() method locates a page in the cache and returns a pointer to 6974 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6975 ** The pBuf element of the returned sqlite3_pcache_page object will be a 6976 ** pointer to a buffer of szPage bytes used to store the content of a 6977 ** single database page. The pExtra element of sqlite3_pcache_page will be 6978 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 6979 ** for each entry in the page cache. 6980 ** 6981 ** The page to be fetched is determined by the key. ^The minimum key value 6982 ** is 1. After it has been retrieved using xFetch, the page is considered 6983 ** to be "pinned". 6984 ** 6985 ** If the requested page is already in the page cache, then the page cache 6986 ** implementation must return a pointer to the page buffer with its content 6987 ** intact. If the requested page is not already in the cache, then the 6988 ** cache implementation should use the value of the createFlag 6989 ** parameter to help it determined what action to take: 6990 ** 6991 ** <table border=1 width=85% align=center> 6992 ** <tr><th> createFlag <th> Behavior when page is not already in cache 6993 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6994 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6995 ** Otherwise return NULL. 6996 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6997 ** NULL if allocating a new page is effectively impossible. 6998 ** </table> 6999 ** 7000 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7001 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 7002 ** failed.)^ In between the to xFetch() calls, SQLite may 7003 ** attempt to unpin one or more cache pages by spilling the content of 7004 ** pinned pages to disk and synching the operating system disk cache. 7005 ** 7006 ** [[the xUnpin() page cache method]] 7007 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7008 ** as its second argument. If the third parameter, discard, is non-zero, 7009 ** then the page must be evicted from the cache. 7010 ** ^If the discard parameter is 7011 ** zero, then the page may be discarded or retained at the discretion of 7012 ** page cache implementation. ^The page cache implementation 7013 ** may choose to evict unpinned pages at any time. 7014 ** 7015 ** The cache must not perform any reference counting. A single 7016 ** call to xUnpin() unpins the page regardless of the number of prior calls 7017 ** to xFetch(). 7018 ** 7019 ** [[the xRekey() page cache methods]] 7020 ** The xRekey() method is used to change the key value associated with the 7021 ** page passed as the second argument. If the cache 7022 ** previously contains an entry associated with newKey, it must be 7023 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7024 ** to be pinned. 7025 ** 7026 ** When SQLite calls the xTruncate() method, the cache must discard all 7027 ** existing cache entries with page numbers (keys) greater than or equal 7028 ** to the value of the iLimit parameter passed to xTruncate(). If any 7029 ** of these pages are pinned, they are implicitly unpinned, meaning that 7030 ** they can be safely discarded. 7031 ** 7032 ** [[the xDestroy() page cache method]] 7033 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7034 ** All resources associated with the specified cache should be freed. ^After 7035 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7036 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7037 ** functions. 7038 ** 7039 ** [[the xShrink() page cache method]] 7040 ** ^SQLite invokes the xShrink() method when it wants the page cache to 7041 ** free up as much of heap memory as possible. The page cache implementation 7042 ** is not obligated to free any memory, but well-behaved implementations should 7043 ** do their best. 7044 */ 7045 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7046 struct sqlite3_pcache_methods2 { 7047 int iVersion; 7048 void *pArg; 7049 int (*xInit)(void*); 7050 void (*xShutdown)(void*); 7051 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7052 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7053 int (*xPagecount)(sqlite3_pcache*); 7054 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7055 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7056 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7057 unsigned oldKey, unsigned newKey); 7058 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7059 void (*xDestroy)(sqlite3_pcache*); 7060 void (*xShrink)(sqlite3_pcache*); 7061 }; 7062 7063 /* 7064 ** This is the obsolete pcache_methods object that has now been replaced 7065 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7066 ** retained in the header file for backwards compatibility only. 7067 */ 7068 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7069 struct sqlite3_pcache_methods { 7070 void *pArg; 7071 int (*xInit)(void*); 7072 void (*xShutdown)(void*); 7073 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7074 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7075 int (*xPagecount)(sqlite3_pcache*); 7076 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7077 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7078 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7079 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7080 void (*xDestroy)(sqlite3_pcache*); 7081 }; 7082 7083 7084 /* 7085 ** CAPI3REF: Online Backup Object 7086 ** 7087 ** The sqlite3_backup object records state information about an ongoing 7088 ** online backup operation. ^The sqlite3_backup object is created by 7089 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 7090 ** [sqlite3_backup_finish()]. 7091 ** 7092 ** See Also: [Using the SQLite Online Backup API] 7093 */ 7094 typedef struct sqlite3_backup sqlite3_backup; 7095 7096 /* 7097 ** CAPI3REF: Online Backup API. 7098 ** 7099 ** The backup API copies the content of one database into another. 7100 ** It is useful either for creating backups of databases or 7101 ** for copying in-memory databases to or from persistent files. 7102 ** 7103 ** See Also: [Using the SQLite Online Backup API] 7104 ** 7105 ** ^SQLite holds a write transaction open on the destination database file 7106 ** for the duration of the backup operation. 7107 ** ^The source database is read-locked only while it is being read; 7108 ** it is not locked continuously for the entire backup operation. 7109 ** ^Thus, the backup may be performed on a live source database without 7110 ** preventing other database connections from 7111 ** reading or writing to the source database while the backup is underway. 7112 ** 7113 ** ^(To perform a backup operation: 7114 ** <ol> 7115 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7116 ** backup, 7117 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7118 ** the data between the two databases, and finally 7119 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7120 ** associated with the backup operation. 7121 ** </ol>)^ 7122 ** There should be exactly one call to sqlite3_backup_finish() for each 7123 ** successful call to sqlite3_backup_init(). 7124 ** 7125 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7126 ** 7127 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7128 ** [database connection] associated with the destination database 7129 ** and the database name, respectively. 7130 ** ^The database name is "main" for the main database, "temp" for the 7131 ** temporary database, or the name specified after the AS keyword in 7132 ** an [ATTACH] statement for an attached database. 7133 ** ^The S and M arguments passed to 7134 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7135 ** and database name of the source database, respectively. 7136 ** ^The source and destination [database connections] (parameters S and D) 7137 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7138 ** an error. 7139 ** 7140 ** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 7141 ** there is already a read or read-write transaction open on the 7142 ** destination database. 7143 ** 7144 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7145 ** returned and an error code and error message are stored in the 7146 ** destination [database connection] D. 7147 ** ^The error code and message for the failed call to sqlite3_backup_init() 7148 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7149 ** [sqlite3_errmsg16()] functions. 7150 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 7151 ** [sqlite3_backup] object. 7152 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7153 ** sqlite3_backup_finish() functions to perform the specified backup 7154 ** operation. 7155 ** 7156 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7157 ** 7158 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7159 ** the source and destination databases specified by [sqlite3_backup] object B. 7160 ** ^If N is negative, all remaining source pages are copied. 7161 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7162 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 7163 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7164 ** from source to destination, then it returns [SQLITE_DONE]. 7165 ** ^If an error occurs while running sqlite3_backup_step(B,N), 7166 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 7167 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7168 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7169 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7170 ** 7171 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7172 ** <ol> 7173 ** <li> the destination database was opened read-only, or 7174 ** <li> the destination database is using write-ahead-log journaling 7175 ** and the destination and source page sizes differ, or 7176 ** <li> the destination database is an in-memory database and the 7177 ** destination and source page sizes differ. 7178 ** </ol>)^ 7179 ** 7180 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7181 ** the [sqlite3_busy_handler | busy-handler function] 7182 ** is invoked (if one is specified). ^If the 7183 ** busy-handler returns non-zero before the lock is available, then 7184 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7185 ** sqlite3_backup_step() can be retried later. ^If the source 7186 ** [database connection] 7187 ** is being used to write to the source database when sqlite3_backup_step() 7188 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7189 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 7190 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7191 ** [SQLITE_READONLY] is returned, then 7192 ** there is no point in retrying the call to sqlite3_backup_step(). These 7193 ** errors are considered fatal.)^ The application must accept 7194 ** that the backup operation has failed and pass the backup operation handle 7195 ** to the sqlite3_backup_finish() to release associated resources. 7196 ** 7197 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7198 ** on the destination file. ^The exclusive lock is not released until either 7199 ** sqlite3_backup_finish() is called or the backup operation is complete 7200 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7201 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 7202 ** lasts for the duration of the sqlite3_backup_step() call. 7203 ** ^Because the source database is not locked between calls to 7204 ** sqlite3_backup_step(), the source database may be modified mid-way 7205 ** through the backup process. ^If the source database is modified by an 7206 ** external process or via a database connection other than the one being 7207 ** used by the backup operation, then the backup will be automatically 7208 ** restarted by the next call to sqlite3_backup_step(). ^If the source 7209 ** database is modified by the using the same database connection as is used 7210 ** by the backup operation, then the backup database is automatically 7211 ** updated at the same time. 7212 ** 7213 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7214 ** 7215 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7216 ** application wishes to abandon the backup operation, the application 7217 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7218 ** ^The sqlite3_backup_finish() interfaces releases all 7219 ** resources associated with the [sqlite3_backup] object. 7220 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7221 ** active write-transaction on the destination database is rolled back. 7222 ** The [sqlite3_backup] object is invalid 7223 ** and may not be used following a call to sqlite3_backup_finish(). 7224 ** 7225 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7226 ** sqlite3_backup_step() errors occurred, regardless or whether or not 7227 ** sqlite3_backup_step() completed. 7228 ** ^If an out-of-memory condition or IO error occurred during any prior 7229 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7230 ** sqlite3_backup_finish() returns the corresponding [error code]. 7231 ** 7232 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7233 ** is not a permanent error and does not affect the return value of 7234 ** sqlite3_backup_finish(). 7235 ** 7236 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7237 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7238 ** 7239 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7240 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7241 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7242 ** in the source database at the conclusion of the most recent 7243 ** sqlite3_backup_step(). 7244 ** ^(The values returned by these functions are only updated by 7245 ** sqlite3_backup_step(). If the source database is modified in a way that 7246 ** changes the size of the source database or the number of pages remaining, 7247 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7248 ** and sqlite3_backup_remaining() until after the next 7249 ** sqlite3_backup_step().)^ 7250 ** 7251 ** <b>Concurrent Usage of Database Handles</b> 7252 ** 7253 ** ^The source [database connection] may be used by the application for other 7254 ** purposes while a backup operation is underway or being initialized. 7255 ** ^If SQLite is compiled and configured to support threadsafe database 7256 ** connections, then the source database connection may be used concurrently 7257 ** from within other threads. 7258 ** 7259 ** However, the application must guarantee that the destination 7260 ** [database connection] is not passed to any other API (by any thread) after 7261 ** sqlite3_backup_init() is called and before the corresponding call to 7262 ** sqlite3_backup_finish(). SQLite does not currently check to see 7263 ** if the application incorrectly accesses the destination [database connection] 7264 ** and so no error code is reported, but the operations may malfunction 7265 ** nevertheless. Use of the destination database connection while a 7266 ** backup is in progress might also also cause a mutex deadlock. 7267 ** 7268 ** If running in [shared cache mode], the application must 7269 ** guarantee that the shared cache used by the destination database 7270 ** is not accessed while the backup is running. In practice this means 7271 ** that the application must guarantee that the disk file being 7272 ** backed up to is not accessed by any connection within the process, 7273 ** not just the specific connection that was passed to sqlite3_backup_init(). 7274 ** 7275 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7276 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7277 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7278 ** APIs are not strictly speaking threadsafe. If they are invoked at the 7279 ** same time as another thread is invoking sqlite3_backup_step() it is 7280 ** possible that they return invalid values. 7281 */ 7282 SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init( 7283 sqlite3 *pDest, /* Destination database handle */ 7284 const char *zDestName, /* Destination database name */ 7285 sqlite3 *pSource, /* Source database handle */ 7286 const char *zSourceName /* Source database name */ 7287 ); 7288 SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage); 7289 SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p); 7290 SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p); 7291 SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p); 7292 7293 /* 7294 ** CAPI3REF: Unlock Notification 7295 ** METHOD: sqlite3 7296 ** 7297 ** ^When running in shared-cache mode, a database operation may fail with 7298 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7299 ** individual tables within the shared-cache cannot be obtained. See 7300 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7301 ** ^This API may be used to register a callback that SQLite will invoke 7302 ** when the connection currently holding the required lock relinquishes it. 7303 ** ^This API is only available if the library was compiled with the 7304 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7305 ** 7306 ** See Also: [Using the SQLite Unlock Notification Feature]. 7307 ** 7308 ** ^Shared-cache locks are released when a database connection concludes 7309 ** its current transaction, either by committing it or rolling it back. 7310 ** 7311 ** ^When a connection (known as the blocked connection) fails to obtain a 7312 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7313 ** identity of the database connection (the blocking connection) that 7314 ** has locked the required resource is stored internally. ^After an 7315 ** application receives an SQLITE_LOCKED error, it may call the 7316 ** sqlite3_unlock_notify() method with the blocked connection handle as 7317 ** the first argument to register for a callback that will be invoked 7318 ** when the blocking connections current transaction is concluded. ^The 7319 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7320 ** call that concludes the blocking connections transaction. 7321 ** 7322 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7323 ** there is a chance that the blocking connection will have already 7324 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7325 ** If this happens, then the specified callback is invoked immediately, 7326 ** from within the call to sqlite3_unlock_notify().)^ 7327 ** 7328 ** ^If the blocked connection is attempting to obtain a write-lock on a 7329 ** shared-cache table, and more than one other connection currently holds 7330 ** a read-lock on the same table, then SQLite arbitrarily selects one of 7331 ** the other connections to use as the blocking connection. 7332 ** 7333 ** ^(There may be at most one unlock-notify callback registered by a 7334 ** blocked connection. If sqlite3_unlock_notify() is called when the 7335 ** blocked connection already has a registered unlock-notify callback, 7336 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7337 ** called with a NULL pointer as its second argument, then any existing 7338 ** unlock-notify callback is canceled. ^The blocked connections 7339 ** unlock-notify callback may also be canceled by closing the blocked 7340 ** connection using [sqlite3_close()]. 7341 ** 7342 ** The unlock-notify callback is not reentrant. If an application invokes 7343 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7344 ** crash or deadlock may be the result. 7345 ** 7346 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7347 ** returns SQLITE_OK. 7348 ** 7349 ** <b>Callback Invocation Details</b> 7350 ** 7351 ** When an unlock-notify callback is registered, the application provides a 7352 ** single void* pointer that is passed to the callback when it is invoked. 7353 ** However, the signature of the callback function allows SQLite to pass 7354 ** it an array of void* context pointers. The first argument passed to 7355 ** an unlock-notify callback is a pointer to an array of void* pointers, 7356 ** and the second is the number of entries in the array. 7357 ** 7358 ** When a blocking connections transaction is concluded, there may be 7359 ** more than one blocked connection that has registered for an unlock-notify 7360 ** callback. ^If two or more such blocked connections have specified the 7361 ** same callback function, then instead of invoking the callback function 7362 ** multiple times, it is invoked once with the set of void* context pointers 7363 ** specified by the blocked connections bundled together into an array. 7364 ** This gives the application an opportunity to prioritize any actions 7365 ** related to the set of unblocked database connections. 7366 ** 7367 ** <b>Deadlock Detection</b> 7368 ** 7369 ** Assuming that after registering for an unlock-notify callback a 7370 ** database waits for the callback to be issued before taking any further 7371 ** action (a reasonable assumption), then using this API may cause the 7372 ** application to deadlock. For example, if connection X is waiting for 7373 ** connection Y's transaction to be concluded, and similarly connection 7374 ** Y is waiting on connection X's transaction, then neither connection 7375 ** will proceed and the system may remain deadlocked indefinitely. 7376 ** 7377 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7378 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7379 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7380 ** unlock-notify callback is registered. The system is said to be in 7381 ** a deadlocked state if connection A has registered for an unlock-notify 7382 ** callback on the conclusion of connection B's transaction, and connection 7383 ** B has itself registered for an unlock-notify callback when connection 7384 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7385 ** the system is also considered to be deadlocked if connection B has 7386 ** registered for an unlock-notify callback on the conclusion of connection 7387 ** C's transaction, where connection C is waiting on connection A. ^Any 7388 ** number of levels of indirection are allowed. 7389 ** 7390 ** <b>The "DROP TABLE" Exception</b> 7391 ** 7392 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7393 ** always appropriate to call sqlite3_unlock_notify(). There is however, 7394 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7395 ** SQLite checks if there are any currently executing SELECT statements 7396 ** that belong to the same connection. If there are, SQLITE_LOCKED is 7397 ** returned. In this case there is no "blocking connection", so invoking 7398 ** sqlite3_unlock_notify() results in the unlock-notify callback being 7399 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7400 ** or "DROP INDEX" query, an infinite loop might be the result. 7401 ** 7402 ** One way around this problem is to check the extended error code returned 7403 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7404 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7405 ** the special "DROP TABLE/INDEX" case, the extended error code is just 7406 ** SQLITE_LOCKED.)^ 7407 */ 7408 SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify( 7409 sqlite3 *pBlocked, /* Waiting connection */ 7410 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7411 void *pNotifyArg /* Argument to pass to xNotify */ 7412 ); 7413 7414 7415 /* 7416 ** CAPI3REF: String Comparison 7417 ** 7418 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7419 ** and extensions to compare the contents of two buffers containing UTF-8 7420 ** strings in a case-independent fashion, using the same definition of "case 7421 ** independence" that SQLite uses internally when comparing identifiers. 7422 */ 7423 SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *); 7424 SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int); 7425 7426 /* 7427 ** CAPI3REF: String Globbing 7428 * 7429 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7430 ** string X matches the [GLOB] pattern P. 7431 ** ^The definition of [GLOB] pattern matching used in 7432 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7433 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7434 ** is case sensitive. 7435 ** 7436 ** Note that this routine returns zero on a match and non-zero if the strings 7437 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7438 ** 7439 ** See also: [sqlite3_strlike()]. 7440 */ 7441 SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr); 7442 7443 /* 7444 ** CAPI3REF: String LIKE Matching 7445 * 7446 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7447 ** string X matches the [LIKE] pattern P with escape character E. 7448 ** ^The definition of [LIKE] pattern matching used in 7449 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7450 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7451 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7452 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7453 ** insensitive - equivalent upper and lower case ASCII characters match 7454 ** one another. 7455 ** 7456 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7457 ** only ASCII characters are case folded. 7458 ** 7459 ** Note that this routine returns zero on a match and non-zero if the strings 7460 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7461 ** 7462 ** See also: [sqlite3_strglob()]. 7463 */ 7464 SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7465 7466 /* 7467 ** CAPI3REF: Error Logging Interface 7468 ** 7469 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7470 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7471 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7472 ** used with [sqlite3_snprintf()] to generate the final output string. 7473 ** 7474 ** The sqlite3_log() interface is intended for use by extensions such as 7475 ** virtual tables, collating functions, and SQL functions. While there is 7476 ** nothing to prevent an application from calling sqlite3_log(), doing so 7477 ** is considered bad form. 7478 ** 7479 ** The zFormat string must not be NULL. 7480 ** 7481 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7482 ** will not use dynamically allocated memory. The log message is stored in 7483 ** a fixed-length buffer on the stack. If the log message is longer than 7484 ** a few hundred characters, it will be truncated to the length of the 7485 ** buffer. 7486 */ 7487 SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...); 7488 7489 /* 7490 ** CAPI3REF: Write-Ahead Log Commit Hook 7491 ** METHOD: sqlite3 7492 ** 7493 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 7494 ** is invoked each time data is committed to a database in wal mode. 7495 ** 7496 ** ^(The callback is invoked by SQLite after the commit has taken place and 7497 ** the associated write-lock on the database released)^, so the implementation 7498 ** may read, write or [checkpoint] the database as required. 7499 ** 7500 ** ^The first parameter passed to the callback function when it is invoked 7501 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 7502 ** registering the callback. ^The second is a copy of the database handle. 7503 ** ^The third parameter is the name of the database that was written to - 7504 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7505 ** is the number of pages currently in the write-ahead log file, 7506 ** including those that were just committed. 7507 ** 7508 ** The callback function should normally return [SQLITE_OK]. ^If an error 7509 ** code is returned, that error will propagate back up through the 7510 ** SQLite code base to cause the statement that provoked the callback 7511 ** to report an error, though the commit will have still occurred. If the 7512 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7513 ** that does not correspond to any valid SQLite error code, the results 7514 ** are undefined. 7515 ** 7516 ** A single database handle may have at most a single write-ahead log callback 7517 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7518 ** previously registered write-ahead log callback. ^Note that the 7519 ** [sqlite3_wal_autocheckpoint()] interface and the 7520 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7521 ** overwrite any prior [sqlite3_wal_hook()] settings. 7522 */ 7523 SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook( 7524 sqlite3*, 7525 int(*)(void *,sqlite3*,const char*,int), 7526 void* 7527 ); 7528 7529 /* 7530 ** CAPI3REF: Configure an auto-checkpoint 7531 ** METHOD: sqlite3 7532 ** 7533 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7534 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 7535 ** to automatically [checkpoint] 7536 ** after committing a transaction if there are N or 7537 ** more frames in the [write-ahead log] file. ^Passing zero or 7538 ** a negative value as the nFrame parameter disables automatic 7539 ** checkpoints entirely. 7540 ** 7541 ** ^The callback registered by this function replaces any existing callback 7542 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7543 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7544 ** configured by this function. 7545 ** 7546 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7547 ** from SQL. 7548 ** 7549 ** ^Checkpoints initiated by this mechanism are 7550 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7551 ** 7552 ** ^Every new [database connection] defaults to having the auto-checkpoint 7553 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7554 ** pages. The use of this interface 7555 ** is only necessary if the default setting is found to be suboptimal 7556 ** for a particular application. 7557 */ 7558 SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7559 7560 /* 7561 ** CAPI3REF: Checkpoint a database 7562 ** METHOD: sqlite3 7563 ** 7564 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7565 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7566 ** 7567 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7568 ** [write-ahead log] for database X on [database connection] D to be 7569 ** transferred into the database file and for the write-ahead log to 7570 ** be reset. See the [checkpointing] documentation for addition 7571 ** information. 7572 ** 7573 ** This interface used to be the only way to cause a checkpoint to 7574 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7575 ** interface was added. This interface is retained for backwards 7576 ** compatibility and as a convenience for applications that need to manually 7577 ** start a callback but which do not need the full power (and corresponding 7578 ** complication) of [sqlite3_wal_checkpoint_v2()]. 7579 */ 7580 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7581 7582 /* 7583 ** CAPI3REF: Checkpoint a database 7584 ** METHOD: sqlite3 7585 ** 7586 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7587 ** operation on database X of [database connection] D in mode M. Status 7588 ** information is written back into integers pointed to by L and C.)^ 7589 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 7590 ** 7591 ** <dl> 7592 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7593 ** ^Checkpoint as many frames as possible without waiting for any database 7594 ** readers or writers to finish, then sync the database file if all frames 7595 ** in the log were checkpointed. ^The [busy-handler callback] 7596 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7597 ** ^On the other hand, passive mode might leave the checkpoint unfinished 7598 ** if there are concurrent readers or writers. 7599 ** 7600 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 7601 ** ^This mode blocks (it invokes the 7602 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 7603 ** database writer and all readers are reading from the most recent database 7604 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 7605 ** database file. ^This mode blocks new database writers while it is pending, 7606 ** but new database readers are allowed to continue unimpeded. 7607 ** 7608 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7609 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7610 ** that after checkpointing the log file it blocks (calls the 7611 ** [busy-handler callback]) 7612 ** until all readers are reading from the database file only. ^This ensures 7613 ** that the next writer will restart the log file from the beginning. 7614 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7615 ** database writer attempts while it is pending, but does not impede readers. 7616 ** 7617 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7618 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7619 ** addition that it also truncates the log file to zero bytes just prior 7620 ** to a successful return. 7621 ** </dl> 7622 ** 7623 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7624 ** the log file or to -1 if the checkpoint could not run because 7625 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7626 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7627 ** log file (including any that were already checkpointed before the function 7628 ** was called) or to -1 if the checkpoint could not run due to an error or 7629 ** because the database is not in WAL mode. ^Note that upon successful 7630 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7631 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7632 ** 7633 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7634 ** any other process is running a checkpoint operation at the same time, the 7635 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7636 ** busy-handler configured, it will not be invoked in this case. 7637 ** 7638 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7639 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7640 ** obtained immediately, and a busy-handler is configured, it is invoked and 7641 ** the writer lock retried until either the busy-handler returns 0 or the lock 7642 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 7643 ** database readers as described above. ^If the busy-handler returns 0 before 7644 ** the writer lock is obtained or while waiting for database readers, the 7645 ** checkpoint operation proceeds from that point in the same way as 7646 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7647 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 7648 ** 7649 ** ^If parameter zDb is NULL or points to a zero length string, then the 7650 ** specified operation is attempted on all WAL databases [attached] to 7651 ** [database connection] db. In this case the 7652 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7653 ** an SQLITE_BUSY error is encountered when processing one or more of the 7654 ** attached WAL databases, the operation is still attempted on any remaining 7655 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7656 ** error occurs while processing an attached database, processing is abandoned 7657 ** and the error code is returned to the caller immediately. ^If no error 7658 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7659 ** databases, SQLITE_OK is returned. 7660 ** 7661 ** ^If database zDb is the name of an attached database that is not in WAL 7662 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7663 ** zDb is not NULL (or a zero length string) and is not the name of any 7664 ** attached database, SQLITE_ERROR is returned to the caller. 7665 ** 7666 ** ^Unless it returns SQLITE_MISUSE, 7667 ** the sqlite3_wal_checkpoint_v2() interface 7668 ** sets the error information that is queried by 7669 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7670 ** 7671 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7672 ** from SQL. 7673 */ 7674 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2( 7675 sqlite3 *db, /* Database handle */ 7676 const char *zDb, /* Name of attached database (or NULL) */ 7677 int eMode, /* SQLITE_CHECKPOINT_* value */ 7678 int *pnLog, /* OUT: Size of WAL log in frames */ 7679 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7680 ); 7681 7682 /* 7683 ** CAPI3REF: Checkpoint Mode Values 7684 ** KEYWORDS: {checkpoint mode} 7685 ** 7686 ** These constants define all valid values for the "checkpoint mode" passed 7687 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7688 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7689 ** meaning of each of these checkpoint modes. 7690 */ 7691 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7692 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7693 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7694 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7695 7696 /* 7697 ** CAPI3REF: Virtual Table Interface Configuration 7698 ** 7699 ** This function may be called by either the [xConnect] or [xCreate] method 7700 ** of a [virtual table] implementation to configure 7701 ** various facets of the virtual table interface. 7702 ** 7703 ** If this interface is invoked outside the context of an xConnect or 7704 ** xCreate virtual table method then the behavior is undefined. 7705 ** 7706 ** At present, there is only one option that may be configured using 7707 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7708 ** may be added in the future. 7709 */ 7710 SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...); 7711 7712 /* 7713 ** CAPI3REF: Virtual Table Configuration Options 7714 ** 7715 ** These macros define the various options to the 7716 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7717 ** can use to customize and optimize their behavior. 7718 ** 7719 ** <dl> 7720 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7721 ** <dd>Calls of the form 7722 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7723 ** where X is an integer. If X is zero, then the [virtual table] whose 7724 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7725 ** support constraints. In this configuration (which is the default) if 7726 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7727 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7728 ** specified as part of the users SQL statement, regardless of the actual 7729 ** ON CONFLICT mode specified. 7730 ** 7731 ** If X is non-zero, then the virtual table implementation guarantees 7732 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7733 ** any modifications to internal or persistent data structures have been made. 7734 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7735 ** is able to roll back a statement or database transaction, and abandon 7736 ** or continue processing the current SQL statement as appropriate. 7737 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7738 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7739 ** had been ABORT. 7740 ** 7741 ** Virtual table implementations that are required to handle OR REPLACE 7742 ** must do so within the [xUpdate] method. If a call to the 7743 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7744 ** CONFLICT policy is REPLACE, the virtual table implementation should 7745 ** silently replace the appropriate rows within the xUpdate callback and 7746 ** return SQLITE_OK. Or, if this is not possible, it may return 7747 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7748 ** constraint handling. 7749 ** </dl> 7750 */ 7751 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7752 7753 /* 7754 ** CAPI3REF: Determine The Virtual Table Conflict Policy 7755 ** 7756 ** This function may only be called from within a call to the [xUpdate] method 7757 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7758 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7759 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7760 ** of the SQL statement that triggered the call to the [xUpdate] method of the 7761 ** [virtual table]. 7762 */ 7763 SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *); 7764 7765 /* 7766 ** CAPI3REF: Conflict resolution modes 7767 ** KEYWORDS: {conflict resolution mode} 7768 ** 7769 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 7770 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 7771 ** is for the SQL statement being evaluated. 7772 ** 7773 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 7774 ** return value from the [sqlite3_set_authorizer()] callback and that 7775 ** [SQLITE_ABORT] is also a [result code]. 7776 */ 7777 #define SQLITE_ROLLBACK 1 7778 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7779 #define SQLITE_FAIL 3 7780 /* #define SQLITE_ABORT 4 // Also an error code */ 7781 #define SQLITE_REPLACE 5 7782 7783 /* 7784 ** CAPI3REF: Prepared Statement Scan Status Opcodes 7785 ** KEYWORDS: {scanstatus options} 7786 ** 7787 ** The following constants can be used for the T parameter to the 7788 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7789 ** different metric for sqlite3_stmt_scanstatus() to return. 7790 ** 7791 ** When the value returned to V is a string, space to hold that string is 7792 ** managed by the prepared statement S and will be automatically freed when 7793 ** S is finalized. 7794 ** 7795 ** <dl> 7796 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7797 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7798 ** set to the total number of times that the X-th loop has run.</dd> 7799 ** 7800 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7801 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7802 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 7803 ** 7804 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7805 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 7806 ** query planner's estimate for the average number of rows output from each 7807 ** iteration of the X-th loop. If the query planner's estimates was accurate, 7808 ** then this value will approximate the quotient NVISIT/NLOOP and the 7809 ** product of this value for all prior loops with the same SELECTID will 7810 ** be the NLOOP value for the current loop. 7811 ** 7812 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 7813 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 7814 ** to a zero-terminated UTF-8 string containing the name of the index or table 7815 ** used for the X-th loop. 7816 ** 7817 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 7818 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 7819 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 7820 ** description for the X-th loop. 7821 ** 7822 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 7823 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 7824 ** "select-id" for the X-th loop. The select-id identifies which query or 7825 ** subquery the loop is part of. The main query has a select-id of zero. 7826 ** The select-id is the same value as is output in the first column 7827 ** of an [EXPLAIN QUERY PLAN] query. 7828 ** </dl> 7829 */ 7830 #define SQLITE_SCANSTAT_NLOOP 0 7831 #define SQLITE_SCANSTAT_NVISIT 1 7832 #define SQLITE_SCANSTAT_EST 2 7833 #define SQLITE_SCANSTAT_NAME 3 7834 #define SQLITE_SCANSTAT_EXPLAIN 4 7835 #define SQLITE_SCANSTAT_SELECTID 5 7836 7837 /* 7838 ** CAPI3REF: Prepared Statement Scan Status 7839 ** METHOD: sqlite3_stmt 7840 ** 7841 ** This interface returns information about the predicted and measured 7842 ** performance for pStmt. Advanced applications can use this 7843 ** interface to compare the predicted and the measured performance and 7844 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 7845 ** 7846 ** Since this interface is expected to be rarely used, it is only 7847 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 7848 ** compile-time option. 7849 ** 7850 ** The "iScanStatusOp" parameter determines which status information to return. 7851 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 7852 ** of this interface is undefined. 7853 ** ^The requested measurement is written into a variable pointed to by 7854 ** the "pOut" parameter. 7855 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 7856 ** Loops are numbered starting from zero. ^If idx is out of range - less than 7857 ** zero or greater than or equal to the total number of loops used to implement 7858 ** the statement - a non-zero value is returned and the variable that pOut 7859 ** points to is unchanged. 7860 ** 7861 ** ^Statistics might not be available for all loops in all statements. ^In cases 7862 ** where there exist loops with no available statistics, this function behaves 7863 ** as if the loop did not exist - it returns non-zero and leave the variable 7864 ** that pOut points to unchanged. 7865 ** 7866 ** See also: [sqlite3_stmt_scanstatus_reset()] 7867 */ 7868 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus( 7869 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 7870 int idx, /* Index of loop to report on */ 7871 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 7872 void *pOut /* Result written here */ 7873 ); 7874 7875 /* 7876 ** CAPI3REF: Zero Scan-Status Counters 7877 ** METHOD: sqlite3_stmt 7878 ** 7879 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 7880 ** 7881 ** This API is only available if the library is built with pre-processor 7882 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 7883 */ 7884 SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 7885 7886 /* 7887 ** CAPI3REF: Flush caches to disk mid-transaction 7888 ** 7889 ** ^If a write-transaction is open on [database connection] D when the 7890 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 7891 ** pages in the pager-cache that are not currently in use are written out 7892 ** to disk. A dirty page may be in use if a database cursor created by an 7893 ** active SQL statement is reading from it, or if it is page 1 of a database 7894 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 7895 ** interface flushes caches for all schemas - "main", "temp", and 7896 ** any [attached] databases. 7897 ** 7898 ** ^If this function needs to obtain extra database locks before dirty pages 7899 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 7900 ** immediately and there is a busy-handler callback configured, it is invoked 7901 ** in the usual manner. ^If the required lock still cannot be obtained, then 7902 ** the database is skipped and an attempt made to flush any dirty pages 7903 ** belonging to the next (if any) database. ^If any databases are skipped 7904 ** because locks cannot be obtained, but no other error occurs, this 7905 ** function returns SQLITE_BUSY. 7906 ** 7907 ** ^If any other error occurs while flushing dirty pages to disk (for 7908 ** example an IO error or out-of-memory condition), then processing is 7909 ** abandoned and an SQLite [error code] is returned to the caller immediately. 7910 ** 7911 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 7912 ** 7913 ** ^This function does not set the database handle error code or message 7914 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 7915 */ 7916 SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3*); 7917 7918 /* 7919 ** CAPI3REF: Low-level system error code 7920 ** 7921 ** ^Attempt to return the underlying operating system error code or error 7922 ** number that caused the most reason I/O error or failure to open a file. 7923 ** The return value is OS-dependent. For example, on unix systems, after 7924 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 7925 ** called to get back the underlying "errno" that caused the problem, such 7926 ** as ENOSPC, EAUTH, EISDIR, and so forth. 7927 */ 7928 SQLITE_API int SQLITE_STDCALL sqlite3_system_errno(sqlite3*); 7929 7930 /* 7931 ** CAPI3REF: Database Snapshot 7932 ** KEYWORDS: {snapshot} 7933 ** EXPERIMENTAL 7934 ** 7935 ** An instance of the snapshot object records the state of a [WAL mode] 7936 ** database for some specific point in history. 7937 ** 7938 ** In [WAL mode], multiple [database connections] that are open on the 7939 ** same database file can each be reading a different historical version 7940 ** of the database file. When a [database connection] begins a read 7941 ** transaction, that connection sees an unchanging copy of the database 7942 ** as it existed for the point in time when the transaction first started. 7943 ** Subsequent changes to the database from other connections are not seen 7944 ** by the reader until a new read transaction is started. 7945 ** 7946 ** The sqlite3_snapshot object records state information about an historical 7947 ** version of the database file so that it is possible to later open a new read 7948 ** transaction that sees that historical version of the database rather than 7949 ** the most recent version. 7950 ** 7951 ** The constructor for this object is [sqlite3_snapshot_get()]. The 7952 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 7953 ** to an historical snapshot (if possible). The destructor for 7954 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 7955 */ 7956 typedef struct sqlite3_snapshot sqlite3_snapshot; 7957 7958 /* 7959 ** CAPI3REF: Record A Database Snapshot 7960 ** EXPERIMENTAL 7961 ** 7962 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 7963 ** new [sqlite3_snapshot] object that records the current state of 7964 ** schema S in database connection D. ^On success, the 7965 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 7966 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 7967 ** ^If schema S of [database connection] D is not a [WAL mode] database 7968 ** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)] 7969 ** leaves the *P value unchanged and returns an appropriate [error code]. 7970 ** 7971 ** The [sqlite3_snapshot] object returned from a successful call to 7972 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 7973 ** to avoid a memory leak. 7974 ** 7975 ** The [sqlite3_snapshot_get()] interface is only available when the 7976 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 7977 */ 7978 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_get( 7979 sqlite3 *db, 7980 const char *zSchema, 7981 sqlite3_snapshot **ppSnapshot 7982 ); 7983 7984 /* 7985 ** CAPI3REF: Start a read transaction on an historical snapshot 7986 ** EXPERIMENTAL 7987 ** 7988 ** ^The [sqlite3_snapshot_open(D,S,P)] interface attempts to move the 7989 ** read transaction that is currently open on schema S of 7990 ** [database connection] D so that it refers to historical [snapshot] P. 7991 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 7992 ** or an appropriate [error code] if it fails. 7993 ** 7994 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 7995 ** the first operation, apart from other sqlite3_snapshot_open() calls, 7996 ** following the [BEGIN] that starts a new read transaction. 7997 ** ^A [snapshot] will fail to open if it has been overwritten by a 7998 ** [checkpoint]. 7999 ** ^A [snapshot] will fail to open if the database connection D has not 8000 ** previously completed at least one read operation against the database 8001 ** file. (Hint: Run "[PRAGMA application_id]" against a newly opened 8002 ** database connection in order to make it ready to use snapshots.) 8003 ** 8004 ** The [sqlite3_snapshot_open()] interface is only available when the 8005 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8006 */ 8007 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_open( 8008 sqlite3 *db, 8009 const char *zSchema, 8010 sqlite3_snapshot *pSnapshot 8011 ); 8012 8013 /* 8014 ** CAPI3REF: Destroy a snapshot 8015 ** EXPERIMENTAL 8016 ** 8017 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8018 ** The application must eventually free every [sqlite3_snapshot] object 8019 ** using this routine to avoid a memory leak. 8020 ** 8021 ** The [sqlite3_snapshot_free()] interface is only available when the 8022 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8023 */ 8024 SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot*); 8025 8026 /* 8027 ** Undo the hack that converts floating point types to integer for 8028 ** builds on processors without floating point support. 8029 */ 8030 #ifdef SQLITE_OMIT_FLOATING_POINT 8031 # undef double 8032 #endif 8033 8034 #ifdef __cplusplus 8035 } /* End of the 'extern "C"' block */ 8036 #endif 8037 #endif /* _SQLITE3_H_ */ 8038 8039 /* 8040 ** 2010 August 30 8041 ** 8042 ** The author disclaims copyright to this source code. In place of 8043 ** a legal notice, here is a blessing: 8044 ** 8045 ** May you do good and not evil. 8046 ** May you find forgiveness for yourself and forgive others. 8047 ** May you share freely, never taking more than you give. 8048 ** 8049 ************************************************************************* 8050 */ 8051 8052 #ifndef _SQLITE3RTREE_H_ 8053 #define _SQLITE3RTREE_H_ 8054 8055 8056 #ifdef __cplusplus 8057 extern "C" { 8058 #endif 8059 8060 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8061 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8062 8063 /* The double-precision datatype used by RTree depends on the 8064 ** SQLITE_RTREE_INT_ONLY compile-time option. 8065 */ 8066 #ifdef SQLITE_RTREE_INT_ONLY 8067 typedef sqlite3_int64 sqlite3_rtree_dbl; 8068 #else 8069 typedef double sqlite3_rtree_dbl; 8070 #endif 8071 8072 /* 8073 ** Register a geometry callback named zGeom that can be used as part of an 8074 ** R-Tree geometry query as follows: 8075 ** 8076 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8077 */ 8078 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback( 8079 sqlite3 *db, 8080 const char *zGeom, 8081 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8082 void *pContext 8083 ); 8084 8085 8086 /* 8087 ** A pointer to a structure of the following type is passed as the first 8088 ** argument to callbacks registered using rtree_geometry_callback(). 8089 */ 8090 struct sqlite3_rtree_geometry { 8091 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8092 int nParam; /* Size of array aParam[] */ 8093 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8094 void *pUser; /* Callback implementation user data */ 8095 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8096 }; 8097 8098 /* 8099 ** Register a 2nd-generation geometry callback named zScore that can be 8100 ** used as part of an R-Tree geometry query as follows: 8101 ** 8102 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8103 */ 8104 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback( 8105 sqlite3 *db, 8106 const char *zQueryFunc, 8107 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8108 void *pContext, 8109 void (*xDestructor)(void*) 8110 ); 8111 8112 8113 /* 8114 ** A pointer to a structure of the following type is passed as the 8115 ** argument to scored geometry callback registered using 8116 ** sqlite3_rtree_query_callback(). 8117 ** 8118 ** Note that the first 5 fields of this structure are identical to 8119 ** sqlite3_rtree_geometry. This structure is a subclass of 8120 ** sqlite3_rtree_geometry. 8121 */ 8122 struct sqlite3_rtree_query_info { 8123 void *pContext; /* pContext from when function registered */ 8124 int nParam; /* Number of function parameters */ 8125 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8126 void *pUser; /* callback can use this, if desired */ 8127 void (*xDelUser)(void*); /* function to free pUser */ 8128 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8129 unsigned int *anQueue; /* Number of pending entries in the queue */ 8130 int nCoord; /* Number of coordinates */ 8131 int iLevel; /* Level of current node or entry */ 8132 int mxLevel; /* The largest iLevel value in the tree */ 8133 sqlite3_int64 iRowid; /* Rowid for current entry */ 8134 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8135 int eParentWithin; /* Visibility of parent node */ 8136 int eWithin; /* OUT: Visiblity */ 8137 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8138 /* The following fields are only available in 3.8.11 and later */ 8139 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8140 }; 8141 8142 /* 8143 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8144 */ 8145 #define NOT_WITHIN 0 /* Object completely outside of query region */ 8146 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8147 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 8148 8149 8150 #ifdef __cplusplus 8151 } /* end of the 'extern "C"' block */ 8152 #endif 8153 8154 #endif /* ifndef _SQLITE3RTREE_H_ */ 8155 8156 /* 8157 ** 2014 May 31 8158 ** 8159 ** The author disclaims copyright to this source code. In place of 8160 ** a legal notice, here is a blessing: 8161 ** 8162 ** May you do good and not evil. 8163 ** May you find forgiveness for yourself and forgive others. 8164 ** May you share freely, never taking more than you give. 8165 ** 8166 ****************************************************************************** 8167 ** 8168 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 8169 ** FTS5 may be extended with: 8170 ** 8171 ** * custom tokenizers, and 8172 ** * custom auxiliary functions. 8173 */ 8174 8175 8176 #ifndef _FTS5_H 8177 #define _FTS5_H 8178 8179 8180 #ifdef __cplusplus 8181 extern "C" { 8182 #endif 8183 8184 /************************************************************************* 8185 ** CUSTOM AUXILIARY FUNCTIONS 8186 ** 8187 ** Virtual table implementations may overload SQL functions by implementing 8188 ** the sqlite3_module.xFindFunction() method. 8189 */ 8190 8191 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 8192 typedef struct Fts5Context Fts5Context; 8193 typedef struct Fts5PhraseIter Fts5PhraseIter; 8194 8195 typedef void (*fts5_extension_function)( 8196 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 8197 Fts5Context *pFts, /* First arg to pass to pApi functions */ 8198 sqlite3_context *pCtx, /* Context for returning result/error */ 8199 int nVal, /* Number of values in apVal[] array */ 8200 sqlite3_value **apVal /* Array of trailing arguments */ 8201 ); 8202 8203 struct Fts5PhraseIter { 8204 const unsigned char *a; 8205 const unsigned char *b; 8206 }; 8207 8208 /* 8209 ** EXTENSION API FUNCTIONS 8210 ** 8211 ** xUserData(pFts): 8212 ** Return a copy of the context pointer the extension function was 8213 ** registered with. 8214 ** 8215 ** xColumnTotalSize(pFts, iCol, pnToken): 8216 ** If parameter iCol is less than zero, set output variable *pnToken 8217 ** to the total number of tokens in the FTS5 table. Or, if iCol is 8218 ** non-negative but less than the number of columns in the table, return 8219 ** the total number of tokens in column iCol, considering all rows in 8220 ** the FTS5 table. 8221 ** 8222 ** If parameter iCol is greater than or equal to the number of columns 8223 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 8224 ** an OOM condition or IO error), an appropriate SQLite error code is 8225 ** returned. 8226 ** 8227 ** xColumnCount(pFts): 8228 ** Return the number of columns in the table. 8229 ** 8230 ** xColumnSize(pFts, iCol, pnToken): 8231 ** If parameter iCol is less than zero, set output variable *pnToken 8232 ** to the total number of tokens in the current row. Or, if iCol is 8233 ** non-negative but less than the number of columns in the table, set 8234 ** *pnToken to the number of tokens in column iCol of the current row. 8235 ** 8236 ** If parameter iCol is greater than or equal to the number of columns 8237 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 8238 ** an OOM condition or IO error), an appropriate SQLite error code is 8239 ** returned. 8240 ** 8241 ** This function may be quite inefficient if used with an FTS5 table 8242 ** created with the "columnsize=0" option. 8243 ** 8244 ** xColumnText: 8245 ** This function attempts to retrieve the text of column iCol of the 8246 ** current document. If successful, (*pz) is set to point to a buffer 8247 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 8248 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 8249 ** if an error occurs, an SQLite error code is returned and the final values 8250 ** of (*pz) and (*pn) are undefined. 8251 ** 8252 ** xPhraseCount: 8253 ** Returns the number of phrases in the current query expression. 8254 ** 8255 ** xPhraseSize: 8256 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 8257 ** are numbered starting from zero. 8258 ** 8259 ** xInstCount: 8260 ** Set *pnInst to the total number of occurrences of all phrases within 8261 ** the query within the current row. Return SQLITE_OK if successful, or 8262 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 8263 ** 8264 ** This API can be quite slow if used with an FTS5 table created with the 8265 ** "detail=none" or "detail=column" option. If the FTS5 table is created 8266 ** with either "detail=none" or "detail=column" and "content=" option 8267 ** (i.e. if it is a contentless table), then this API always returns 0. 8268 ** 8269 ** xInst: 8270 ** Query for the details of phrase match iIdx within the current row. 8271 ** Phrase matches are numbered starting from zero, so the iIdx argument 8272 ** should be greater than or equal to zero and smaller than the value 8273 ** output by xInstCount(). 8274 ** 8275 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 8276 ** to the column in which it occurs and *piOff the token offset of the 8277 ** first token of the phrase. The exception is if the table was created 8278 ** with the offsets=0 option specified. In this case *piOff is always 8279 ** set to -1. 8280 ** 8281 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 8282 ** if an error occurs. 8283 ** 8284 ** This API can be quite slow if used with an FTS5 table created with the 8285 ** "detail=none" or "detail=column" option. 8286 ** 8287 ** xRowid: 8288 ** Returns the rowid of the current row. 8289 ** 8290 ** xTokenize: 8291 ** Tokenize text using the tokenizer belonging to the FTS5 table. 8292 ** 8293 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 8294 ** This API function is used to query the FTS table for phrase iPhrase 8295 ** of the current query. Specifically, a query equivalent to: 8296 ** 8297 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 8298 ** 8299 ** with $p set to a phrase equivalent to the phrase iPhrase of the 8300 ** current query is executed. For each row visited, the callback function 8301 ** passed as the fourth argument is invoked. The context and API objects 8302 ** passed to the callback function may be used to access the properties of 8303 ** each matched row. Invoking Api.xUserData() returns a copy of the pointer 8304 ** passed as the third argument to pUserData. 8305 ** 8306 ** If the callback function returns any value other than SQLITE_OK, the 8307 ** query is abandoned and the xQueryPhrase function returns immediately. 8308 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 8309 ** Otherwise, the error code is propagated upwards. 8310 ** 8311 ** If the query runs to completion without incident, SQLITE_OK is returned. 8312 ** Or, if some error occurs before the query completes or is aborted by 8313 ** the callback, an SQLite error code is returned. 8314 ** 8315 ** 8316 ** xSetAuxdata(pFts5, pAux, xDelete) 8317 ** 8318 ** Save the pointer passed as the second argument as the extension functions 8319 ** "auxiliary data". The pointer may then be retrieved by the current or any 8320 ** future invocation of the same fts5 extension function made as part of 8321 ** of the same MATCH query using the xGetAuxdata() API. 8322 ** 8323 ** Each extension function is allocated a single auxiliary data slot for 8324 ** each FTS query (MATCH expression). If the extension function is invoked 8325 ** more than once for a single FTS query, then all invocations share a 8326 ** single auxiliary data context. 8327 ** 8328 ** If there is already an auxiliary data pointer when this function is 8329 ** invoked, then it is replaced by the new pointer. If an xDelete callback 8330 ** was specified along with the original pointer, it is invoked at this 8331 ** point. 8332 ** 8333 ** The xDelete callback, if one is specified, is also invoked on the 8334 ** auxiliary data pointer after the FTS5 query has finished. 8335 ** 8336 ** If an error (e.g. an OOM condition) occurs within this function, an 8337 ** the auxiliary data is set to NULL and an error code returned. If the 8338 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 8339 ** pointer before returning. 8340 ** 8341 ** 8342 ** xGetAuxdata(pFts5, bClear) 8343 ** 8344 ** Returns the current auxiliary data pointer for the fts5 extension 8345 ** function. See the xSetAuxdata() method for details. 8346 ** 8347 ** If the bClear argument is non-zero, then the auxiliary data is cleared 8348 ** (set to NULL) before this function returns. In this case the xDelete, 8349 ** if any, is not invoked. 8350 ** 8351 ** 8352 ** xRowCount(pFts5, pnRow) 8353 ** 8354 ** This function is used to retrieve the total number of rows in the table. 8355 ** In other words, the same value that would be returned by: 8356 ** 8357 ** SELECT count(*) FROM ftstable; 8358 ** 8359 ** xPhraseFirst() 8360 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 8361 ** method, to iterate through all instances of a single query phrase within 8362 ** the current row. This is the same information as is accessible via the 8363 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 8364 ** to use, this API may be faster under some circumstances. To iterate 8365 ** through instances of phrase iPhrase, use the following code: 8366 ** 8367 ** Fts5PhraseIter iter; 8368 ** int iCol, iOff; 8369 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 8370 ** iCol>=0; 8371 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 8372 ** ){ 8373 ** // An instance of phrase iPhrase at offset iOff of column iCol 8374 ** } 8375 ** 8376 ** The Fts5PhraseIter structure is defined above. Applications should not 8377 ** modify this structure directly - it should only be used as shown above 8378 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 8379 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 8380 ** 8381 ** This API can be quite slow if used with an FTS5 table created with the 8382 ** "detail=none" or "detail=column" option. If the FTS5 table is created 8383 ** with either "detail=none" or "detail=column" and "content=" option 8384 ** (i.e. if it is a contentless table), then this API always iterates 8385 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 8386 ** 8387 ** xPhraseNext() 8388 ** See xPhraseFirst above. 8389 ** 8390 ** xPhraseFirstColumn() 8391 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 8392 ** and xPhraseNext() APIs described above. The difference is that instead 8393 ** of iterating through all instances of a phrase in the current row, these 8394 ** APIs are used to iterate through the set of columns in the current row 8395 ** that contain one or more instances of a specified phrase. For example: 8396 ** 8397 ** Fts5PhraseIter iter; 8398 ** int iCol; 8399 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 8400 ** iCol>=0; 8401 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 8402 ** ){ 8403 ** // Column iCol contains at least one instance of phrase iPhrase 8404 ** } 8405 ** 8406 ** This API can be quite slow if used with an FTS5 table created with the 8407 ** "detail=none" option. If the FTS5 table is created with either 8408 ** "detail=none" "content=" option (i.e. if it is a contentless table), 8409 ** then this API always iterates through an empty set (all calls to 8410 ** xPhraseFirstColumn() set iCol to -1). 8411 ** 8412 ** The information accessed using this API and its companion 8413 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 8414 ** (or xInst/xInstCount). The chief advantage of this API is that it is 8415 ** significantly more efficient than those alternatives when used with 8416 ** "detail=column" tables. 8417 ** 8418 ** xPhraseNextColumn() 8419 ** See xPhraseFirstColumn above. 8420 */ 8421 struct Fts5ExtensionApi { 8422 int iVersion; /* Currently always set to 3 */ 8423 8424 void *(*xUserData)(Fts5Context*); 8425 8426 int (*xColumnCount)(Fts5Context*); 8427 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 8428 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 8429 8430 int (*xTokenize)(Fts5Context*, 8431 const char *pText, int nText, /* Text to tokenize */ 8432 void *pCtx, /* Context passed to xToken() */ 8433 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 8434 ); 8435 8436 int (*xPhraseCount)(Fts5Context*); 8437 int (*xPhraseSize)(Fts5Context*, int iPhrase); 8438 8439 int (*xInstCount)(Fts5Context*, int *pnInst); 8440 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 8441 8442 sqlite3_int64 (*xRowid)(Fts5Context*); 8443 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 8444 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 8445 8446 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 8447 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 8448 ); 8449 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 8450 void *(*xGetAuxdata)(Fts5Context*, int bClear); 8451 8452 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 8453 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 8454 8455 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 8456 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 8457 }; 8458 8459 /* 8460 ** CUSTOM AUXILIARY FUNCTIONS 8461 *************************************************************************/ 8462 8463 /************************************************************************* 8464 ** CUSTOM TOKENIZERS 8465 ** 8466 ** Applications may also register custom tokenizer types. A tokenizer 8467 ** is registered by providing fts5 with a populated instance of the 8468 ** following structure. All structure methods must be defined, setting 8469 ** any member of the fts5_tokenizer struct to NULL leads to undefined 8470 ** behaviour. The structure methods are expected to function as follows: 8471 ** 8472 ** xCreate: 8473 ** This function is used to allocate and inititalize a tokenizer instance. 8474 ** A tokenizer instance is required to actually tokenize text. 8475 ** 8476 ** The first argument passed to this function is a copy of the (void*) 8477 ** pointer provided by the application when the fts5_tokenizer object 8478 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 8479 ** The second and third arguments are an array of nul-terminated strings 8480 ** containing the tokenizer arguments, if any, specified following the 8481 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 8482 ** to create the FTS5 table. 8483 ** 8484 ** The final argument is an output variable. If successful, (*ppOut) 8485 ** should be set to point to the new tokenizer handle and SQLITE_OK 8486 ** returned. If an error occurs, some value other than SQLITE_OK should 8487 ** be returned. In this case, fts5 assumes that the final value of *ppOut 8488 ** is undefined. 8489 ** 8490 ** xDelete: 8491 ** This function is invoked to delete a tokenizer handle previously 8492 ** allocated using xCreate(). Fts5 guarantees that this function will 8493 ** be invoked exactly once for each successful call to xCreate(). 8494 ** 8495 ** xTokenize: 8496 ** This function is expected to tokenize the nText byte string indicated 8497 ** by argument pText. pText may or may not be nul-terminated. The first 8498 ** argument passed to this function is a pointer to an Fts5Tokenizer object 8499 ** returned by an earlier call to xCreate(). 8500 ** 8501 ** The second argument indicates the reason that FTS5 is requesting 8502 ** tokenization of the supplied text. This is always one of the following 8503 ** four values: 8504 ** 8505 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 8506 ** or removed from the FTS table. The tokenizer is being invoked to 8507 ** determine the set of tokens to add to (or delete from) the 8508 ** FTS index. 8509 ** 8510 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 8511 ** against the FTS index. The tokenizer is being called to tokenize 8512 ** a bareword or quoted string specified as part of the query. 8513 ** 8514 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 8515 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 8516 ** followed by a "*" character, indicating that the last token 8517 ** returned by the tokenizer will be treated as a token prefix. 8518 ** 8519 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 8520 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 8521 ** function. Or an fts5_api.xColumnSize() request made by the same 8522 ** on a columnsize=0 database. 8523 ** </ul> 8524 ** 8525 ** For each token in the input string, the supplied callback xToken() must 8526 ** be invoked. The first argument to it should be a copy of the pointer 8527 ** passed as the second argument to xTokenize(). The third and fourth 8528 ** arguments are a pointer to a buffer containing the token text, and the 8529 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 8530 ** of the first byte of and first byte immediately following the text from 8531 ** which the token is derived within the input. 8532 ** 8533 ** The second argument passed to the xToken() callback ("tflags") should 8534 ** normally be set to 0. The exception is if the tokenizer supports 8535 ** synonyms. In this case see the discussion below for details. 8536 ** 8537 ** FTS5 assumes the xToken() callback is invoked for each token in the 8538 ** order that they occur within the input text. 8539 ** 8540 ** If an xToken() callback returns any value other than SQLITE_OK, then 8541 ** the tokenization should be abandoned and the xTokenize() method should 8542 ** immediately return a copy of the xToken() return value. Or, if the 8543 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 8544 ** if an error occurs with the xTokenize() implementation itself, it 8545 ** may abandon the tokenization and return any error code other than 8546 ** SQLITE_OK or SQLITE_DONE. 8547 ** 8548 ** SYNONYM SUPPORT 8549 ** 8550 ** Custom tokenizers may also support synonyms. Consider a case in which a 8551 ** user wishes to query for a phrase such as "first place". Using the 8552 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 8553 ** of "first place" within the document set, but not alternative forms 8554 ** such as "1st place". In some applications, it would be better to match 8555 ** all instances of "first place" or "1st place" regardless of which form 8556 ** the user specified in the MATCH query text. 8557 ** 8558 ** There are several ways to approach this in FTS5: 8559 ** 8560 ** <ol><li> By mapping all synonyms to a single token. In this case, the 8561 ** In the above example, this means that the tokenizer returns the 8562 ** same token for inputs "first" and "1st". Say that token is in 8563 ** fact "first", so that when the user inserts the document "I won 8564 ** 1st place" entries are added to the index for tokens "i", "won", 8565 ** "first" and "place". If the user then queries for '1st + place', 8566 ** the tokenizer substitutes "first" for "1st" and the query works 8567 ** as expected. 8568 ** 8569 ** <li> By adding multiple synonyms for a single term to the FTS index. 8570 ** In this case, when tokenizing query text, the tokenizer may 8571 ** provide multiple synonyms for a single term within the document. 8572 ** FTS5 then queries the index for each synonym individually. For 8573 ** example, faced with the query: 8574 ** 8575 ** <codeblock> 8576 ** ... MATCH 'first place'</codeblock> 8577 ** 8578 ** the tokenizer offers both "1st" and "first" as synonyms for the 8579 ** first token in the MATCH query and FTS5 effectively runs a query 8580 ** similar to: 8581 ** 8582 ** <codeblock> 8583 ** ... MATCH '(first OR 1st) place'</codeblock> 8584 ** 8585 ** except that, for the purposes of auxiliary functions, the query 8586 ** still appears to contain just two phrases - "(first OR 1st)" 8587 ** being treated as a single phrase. 8588 ** 8589 ** <li> By adding multiple synonyms for a single term to the FTS index. 8590 ** Using this method, when tokenizing document text, the tokenizer 8591 ** provides multiple synonyms for each token. So that when a 8592 ** document such as "I won first place" is tokenized, entries are 8593 ** added to the FTS index for "i", "won", "first", "1st" and 8594 ** "place". 8595 ** 8596 ** This way, even if the tokenizer does not provide synonyms 8597 ** when tokenizing query text (it should not - to do would be 8598 ** inefficient), it doesn't matter if the user queries for 8599 ** 'first + place' or '1st + place', as there are entires in the 8600 ** FTS index corresponding to both forms of the first token. 8601 ** </ol> 8602 ** 8603 ** Whether it is parsing document or query text, any call to xToken that 8604 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 8605 ** is considered to supply a synonym for the previous token. For example, 8606 ** when parsing the document "I won first place", a tokenizer that supports 8607 ** synonyms would call xToken() 5 times, as follows: 8608 ** 8609 ** <codeblock> 8610 ** xToken(pCtx, 0, "i", 1, 0, 1); 8611 ** xToken(pCtx, 0, "won", 3, 2, 5); 8612 ** xToken(pCtx, 0, "first", 5, 6, 11); 8613 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 8614 ** xToken(pCtx, 0, "place", 5, 12, 17); 8615 **</codeblock> 8616 ** 8617 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 8618 ** xToken() is called. Multiple synonyms may be specified for a single token 8619 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 8620 ** There is no limit to the number of synonyms that may be provided for a 8621 ** single token. 8622 ** 8623 ** In many cases, method (1) above is the best approach. It does not add 8624 ** extra data to the FTS index or require FTS5 to query for multiple terms, 8625 ** so it is efficient in terms of disk space and query speed. However, it 8626 ** does not support prefix queries very well. If, as suggested above, the 8627 ** token "first" is subsituted for "1st" by the tokenizer, then the query: 8628 ** 8629 ** <codeblock> 8630 ** ... MATCH '1s*'</codeblock> 8631 ** 8632 ** will not match documents that contain the token "1st" (as the tokenizer 8633 ** will probably not map "1s" to any prefix of "first"). 8634 ** 8635 ** For full prefix support, method (3) may be preferred. In this case, 8636 ** because the index contains entries for both "first" and "1st", prefix 8637 ** queries such as 'fi*' or '1s*' will match correctly. However, because 8638 ** extra entries are added to the FTS index, this method uses more space 8639 ** within the database. 8640 ** 8641 ** Method (2) offers a midpoint between (1) and (3). Using this method, 8642 ** a query such as '1s*' will match documents that contain the literal 8643 ** token "1st", but not "first" (assuming the tokenizer is not able to 8644 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 8645 ** will match against "1st" and "first". This method does not require 8646 ** extra disk space, as no extra entries are added to the FTS index. 8647 ** On the other hand, it may require more CPU cycles to run MATCH queries, 8648 ** as separate queries of the FTS index are required for each synonym. 8649 ** 8650 ** When using methods (2) or (3), it is important that the tokenizer only 8651 ** provide synonyms when tokenizing document text (method (2)) or query 8652 ** text (method (3)), not both. Doing so will not cause any errors, but is 8653 ** inefficient. 8654 */ 8655 typedef struct Fts5Tokenizer Fts5Tokenizer; 8656 typedef struct fts5_tokenizer fts5_tokenizer; 8657 struct fts5_tokenizer { 8658 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 8659 void (*xDelete)(Fts5Tokenizer*); 8660 int (*xTokenize)(Fts5Tokenizer*, 8661 void *pCtx, 8662 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 8663 const char *pText, int nText, 8664 int (*xToken)( 8665 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 8666 int tflags, /* Mask of FTS5_TOKEN_* flags */ 8667 const char *pToken, /* Pointer to buffer containing token */ 8668 int nToken, /* Size of token in bytes */ 8669 int iStart, /* Byte offset of token within input text */ 8670 int iEnd /* Byte offset of end of token within input text */ 8671 ) 8672 ); 8673 }; 8674 8675 /* Flags that may be passed as the third argument to xTokenize() */ 8676 #define FTS5_TOKENIZE_QUERY 0x0001 8677 #define FTS5_TOKENIZE_PREFIX 0x0002 8678 #define FTS5_TOKENIZE_DOCUMENT 0x0004 8679 #define FTS5_TOKENIZE_AUX 0x0008 8680 8681 /* Flags that may be passed by the tokenizer implementation back to FTS5 8682 ** as the third argument to the supplied xToken callback. */ 8683 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 8684 8685 /* 8686 ** END OF CUSTOM TOKENIZERS 8687 *************************************************************************/ 8688 8689 /************************************************************************* 8690 ** FTS5 EXTENSION REGISTRATION API 8691 */ 8692 typedef struct fts5_api fts5_api; 8693 struct fts5_api { 8694 int iVersion; /* Currently always set to 2 */ 8695 8696 /* Create a new tokenizer */ 8697 int (*xCreateTokenizer)( 8698 fts5_api *pApi, 8699 const char *zName, 8700 void *pContext, 8701 fts5_tokenizer *pTokenizer, 8702 void (*xDestroy)(void*) 8703 ); 8704 8705 /* Find an existing tokenizer */ 8706 int (*xFindTokenizer)( 8707 fts5_api *pApi, 8708 const char *zName, 8709 void **ppContext, 8710 fts5_tokenizer *pTokenizer 8711 ); 8712 8713 /* Create a new auxiliary function */ 8714 int (*xCreateFunction)( 8715 fts5_api *pApi, 8716 const char *zName, 8717 void *pContext, 8718 fts5_extension_function xFunction, 8719 void (*xDestroy)(void*) 8720 ); 8721 }; 8722 8723 /* 8724 ** END OF REGISTRATION API 8725 *************************************************************************/ 8726 8727 #ifdef __cplusplus 8728 } /* end of the 'extern "C"' block */ 8729 #endif 8730 8731 #endif /* _FTS5_H */ 8732 8733 8734