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_APICALL 58 # define SQLITE_APICALL 59 #endif 60 #ifndef SQLITE_STDCALL 61 # define SQLITE_STDCALL SQLITE_APICALL 62 #endif 63 #ifndef SQLITE_CALLBACK 64 # define SQLITE_CALLBACK 65 #endif 66 #ifndef SQLITE_SYSAPI 67 # define SQLITE_SYSAPI 68 #endif 69 70 /* 71 ** These no-op macros are used in front of interfaces to mark those 72 ** interfaces as either deprecated or experimental. New applications 73 ** should not use deprecated interfaces - they are supported for backwards 74 ** compatibility only. Application writers should be aware that 75 ** experimental interfaces are subject to change in point releases. 76 ** 77 ** These macros used to resolve to various kinds of compiler magic that 78 ** would generate warning messages when they were used. But that 79 ** compiler magic ended up generating such a flurry of bug reports 80 ** that we have taken it all out and gone back to using simple 81 ** noop macros. 82 */ 83 #define SQLITE_DEPRECATED 84 #define SQLITE_EXPERIMENTAL 85 86 /* 87 ** Ensure these symbols were not defined by some previous header file. 88 */ 89 #ifdef SQLITE_VERSION 90 # undef SQLITE_VERSION 91 #endif 92 #ifdef SQLITE_VERSION_NUMBER 93 # undef SQLITE_VERSION_NUMBER 94 #endif 95 96 /* 97 ** CAPI3REF: Compile-Time Library Version Numbers 98 ** 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100 ** evaluates to a string literal that is the SQLite version in the 101 ** format "X.Y.Z" where X is the major version number (always 3 for 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105 ** numbers used in [SQLITE_VERSION].)^ 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107 ** be larger than the release from which it is derived. Either Y will 108 ** be held constant and Z will be incremented or else Y will be incremented 109 ** and Z will be reset to zero. 110 ** 111 ** Since [version 3.6.18] ([dateof:3.6.18]), 112 ** SQLite source code has been stored in the 113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115 ** a string which identifies a particular check-in of SQLite 116 ** within its configuration management system. ^The SQLITE_SOURCE_ID 117 ** string contains the date and time of the check-in (UTC) and a SHA1 118 ** or SHA3-256 hash of the entire source tree. 119 ** 120 ** See also: [sqlite3_libversion()], 121 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 122 ** [sqlite_version()] and [sqlite_source_id()]. 123 */ 124 #define SQLITE_VERSION "3.18.2" 125 #define SQLITE_VERSION_NUMBER 3018002 126 #define SQLITE_SOURCE_ID "2017-06-17 09:59:36 036ebf729e4b21035d7f4f8e35a6f705e6bf99887889e2dc14ebf2242e7930dd" 127 128 /* 129 ** CAPI3REF: Run-Time Library Version Numbers 130 ** KEYWORDS: sqlite3_version sqlite3_sourceid 131 ** 132 ** These interfaces provide the same information as the [SQLITE_VERSION], 133 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 134 ** but are associated with the library instead of the header file. ^(Cautious 135 ** programmers might include assert() statements in their application to 136 ** verify that values returned by these interfaces match the macros in 137 ** the header, and thus ensure that the application is 138 ** compiled with matching library and header files. 139 ** 140 ** <blockquote><pre> 141 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 142 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 143 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 144 ** </pre></blockquote>)^ 145 ** 146 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 147 ** macro. ^The sqlite3_libversion() function returns a pointer to the 148 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 149 ** function is provided for use in DLLs since DLL users usually do not have 150 ** direct access to string constants within the DLL. ^The 151 ** sqlite3_libversion_number() function returns an integer equal to 152 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 153 ** a pointer to a string constant whose value is the same as the 154 ** [SQLITE_SOURCE_ID] C preprocessor macro. 155 ** 156 ** See also: [sqlite_version()] and [sqlite_source_id()]. 157 */ 158 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 159 SQLITE_API const char *sqlite3_libversion(void); 160 SQLITE_API const char *sqlite3_sourceid(void); 161 SQLITE_API int sqlite3_libversion_number(void); 162 163 /* 164 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 165 ** 166 ** ^The sqlite3_compileoption_used() function returns 0 or 1 167 ** indicating whether the specified option was defined at 168 ** compile time. ^The SQLITE_ prefix may be omitted from the 169 ** option name passed to sqlite3_compileoption_used(). 170 ** 171 ** ^The sqlite3_compileoption_get() function allows iterating 172 ** over the list of options that were defined at compile time by 173 ** returning the N-th compile time option string. ^If N is out of range, 174 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 175 ** prefix is omitted from any strings returned by 176 ** sqlite3_compileoption_get(). 177 ** 178 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 179 ** and sqlite3_compileoption_get() may be omitted by specifying the 180 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 181 ** 182 ** See also: SQL functions [sqlite_compileoption_used()] and 183 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 184 */ 185 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 186 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 187 SQLITE_API const char *sqlite3_compileoption_get(int N); 188 #endif 189 190 /* 191 ** CAPI3REF: Test To See If The Library Is Threadsafe 192 ** 193 ** ^The sqlite3_threadsafe() function returns zero if and only if 194 ** SQLite was compiled with mutexing code omitted due to the 195 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 196 ** 197 ** SQLite can be compiled with or without mutexes. When 198 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 199 ** are enabled and SQLite is threadsafe. When the 200 ** [SQLITE_THREADSAFE] macro is 0, 201 ** the mutexes are omitted. Without the mutexes, it is not safe 202 ** to use SQLite concurrently from more than one thread. 203 ** 204 ** Enabling mutexes incurs a measurable performance penalty. 205 ** So if speed is of utmost importance, it makes sense to disable 206 ** the mutexes. But for maximum safety, mutexes should be enabled. 207 ** ^The default behavior is for mutexes to be enabled. 208 ** 209 ** This interface can be used by an application to make sure that the 210 ** version of SQLite that it is linking against was compiled with 211 ** the desired setting of the [SQLITE_THREADSAFE] macro. 212 ** 213 ** This interface only reports on the compile-time mutex setting 214 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 215 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 216 ** can be fully or partially disabled using a call to [sqlite3_config()] 217 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 218 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 219 ** sqlite3_threadsafe() function shows only the compile-time setting of 220 ** thread safety, not any run-time changes to that setting made by 221 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 222 ** is unchanged by calls to sqlite3_config().)^ 223 ** 224 ** See the [threading mode] documentation for additional information. 225 */ 226 SQLITE_API int sqlite3_threadsafe(void); 227 228 /* 229 ** CAPI3REF: Database Connection Handle 230 ** KEYWORDS: {database connection} {database connections} 231 ** 232 ** Each open SQLite database is represented by a pointer to an instance of 233 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 234 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 235 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 236 ** and [sqlite3_close_v2()] are its destructors. There are many other 237 ** interfaces (such as 238 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 239 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 240 ** sqlite3 object. 241 */ 242 typedef struct sqlite3 sqlite3; 243 244 /* 245 ** CAPI3REF: 64-Bit Integer Types 246 ** KEYWORDS: sqlite_int64 sqlite_uint64 247 ** 248 ** Because there is no cross-platform way to specify 64-bit integer types 249 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 250 ** 251 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 252 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 253 ** compatibility only. 254 ** 255 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 256 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 257 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 258 ** between 0 and +18446744073709551615 inclusive. 259 */ 260 #ifdef SQLITE_INT64_TYPE 261 typedef SQLITE_INT64_TYPE sqlite_int64; 262 # ifdef SQLITE_UINT64_TYPE 263 typedef SQLITE_UINT64_TYPE sqlite_uint64; 264 # else 265 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 266 # endif 267 #elif defined(_MSC_VER) || defined(__BORLANDC__) 268 typedef __int64 sqlite_int64; 269 typedef unsigned __int64 sqlite_uint64; 270 #else 271 typedef long long int sqlite_int64; 272 typedef unsigned long long int sqlite_uint64; 273 #endif 274 typedef sqlite_int64 sqlite3_int64; 275 typedef sqlite_uint64 sqlite3_uint64; 276 277 /* 278 ** If compiling for a processor that lacks floating point support, 279 ** substitute integer for floating-point. 280 */ 281 #ifdef SQLITE_OMIT_FLOATING_POINT 282 # define double sqlite3_int64 283 #endif 284 285 /* 286 ** CAPI3REF: Closing A Database Connection 287 ** DESTRUCTOR: sqlite3 288 ** 289 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 290 ** for the [sqlite3] object. 291 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 292 ** the [sqlite3] object is successfully destroyed and all associated 293 ** resources are deallocated. 294 ** 295 ** ^If the database connection is associated with unfinalized prepared 296 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 297 ** will leave the database connection open and return [SQLITE_BUSY]. 298 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 299 ** and/or unfinished sqlite3_backups, then the database connection becomes 300 ** an unusable "zombie" which will automatically be deallocated when the 301 ** last prepared statement is finalized or the last sqlite3_backup is 302 ** finished. The sqlite3_close_v2() interface is intended for use with 303 ** host languages that are garbage collected, and where the order in which 304 ** destructors are called is arbitrary. 305 ** 306 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 307 ** [sqlite3_blob_close | close] all [BLOB handles], and 308 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 309 ** with the [sqlite3] object prior to attempting to close the object. ^If 310 ** sqlite3_close_v2() is called on a [database connection] that still has 311 ** outstanding [prepared statements], [BLOB handles], and/or 312 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 313 ** of resources is deferred until all [prepared statements], [BLOB handles], 314 ** and [sqlite3_backup] objects are also destroyed. 315 ** 316 ** ^If an [sqlite3] object is destroyed while a transaction is open, 317 ** the transaction is automatically rolled back. 318 ** 319 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 320 ** must be either a NULL 321 ** pointer or an [sqlite3] object pointer obtained 322 ** from [sqlite3_open()], [sqlite3_open16()], or 323 ** [sqlite3_open_v2()], and not previously closed. 324 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 325 ** argument is a harmless no-op. 326 */ 327 SQLITE_API int sqlite3_close(sqlite3*); 328 SQLITE_API int sqlite3_close_v2(sqlite3*); 329 330 /* 331 ** The type for a callback function. 332 ** This is legacy and deprecated. It is included for historical 333 ** compatibility and is not documented. 334 */ 335 typedef int (*sqlite3_callback)(void*,int,char**, char**); 336 337 /* 338 ** CAPI3REF: One-Step Query Execution Interface 339 ** METHOD: sqlite3 340 ** 341 ** The sqlite3_exec() interface is a convenience wrapper around 342 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 343 ** that allows an application to run multiple statements of SQL 344 ** without having to use a lot of C code. 345 ** 346 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 347 ** semicolon-separate SQL statements passed into its 2nd argument, 348 ** in the context of the [database connection] passed in as its 1st 349 ** argument. ^If the callback function of the 3rd argument to 350 ** sqlite3_exec() is not NULL, then it is invoked for each result row 351 ** coming out of the evaluated SQL statements. ^The 4th argument to 352 ** sqlite3_exec() is relayed through to the 1st argument of each 353 ** callback invocation. ^If the callback pointer to sqlite3_exec() 354 ** is NULL, then no callback is ever invoked and result rows are 355 ** ignored. 356 ** 357 ** ^If an error occurs while evaluating the SQL statements passed into 358 ** sqlite3_exec(), then execution of the current statement stops and 359 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 360 ** is not NULL then any error message is written into memory obtained 361 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 362 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 363 ** on error message strings returned through the 5th parameter of 364 ** sqlite3_exec() after the error message string is no longer needed. 365 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 366 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 367 ** NULL before returning. 368 ** 369 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 370 ** routine returns SQLITE_ABORT without invoking the callback again and 371 ** without running any subsequent SQL statements. 372 ** 373 ** ^The 2nd argument to the sqlite3_exec() callback function is the 374 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 375 ** callback is an array of pointers to strings obtained as if from 376 ** [sqlite3_column_text()], one for each column. ^If an element of a 377 ** result row is NULL then the corresponding string pointer for the 378 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 379 ** sqlite3_exec() callback is an array of pointers to strings where each 380 ** entry represents the name of corresponding result column as obtained 381 ** from [sqlite3_column_name()]. 382 ** 383 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 384 ** to an empty string, or a pointer that contains only whitespace and/or 385 ** SQL comments, then no SQL statements are evaluated and the database 386 ** is not changed. 387 ** 388 ** Restrictions: 389 ** 390 ** <ul> 391 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 392 ** is a valid and open [database connection]. 393 ** <li> The application must not close the [database connection] specified by 394 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 395 ** <li> The application must not modify the SQL statement text passed into 396 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 397 ** </ul> 398 */ 399 SQLITE_API int sqlite3_exec( 400 sqlite3*, /* An open database */ 401 const char *sql, /* SQL to be evaluated */ 402 int (*callback)(void*,int,char**,char**), /* Callback function */ 403 void *, /* 1st argument to callback */ 404 char **errmsg /* Error msg written here */ 405 ); 406 407 /* 408 ** CAPI3REF: Result Codes 409 ** KEYWORDS: {result code definitions} 410 ** 411 ** Many SQLite functions return an integer result code from the set shown 412 ** here in order to indicate success or failure. 413 ** 414 ** New error codes may be added in future versions of SQLite. 415 ** 416 ** See also: [extended result code definitions] 417 */ 418 #define SQLITE_OK 0 /* Successful result */ 419 /* beginning-of-error-codes */ 420 #define SQLITE_ERROR 1 /* SQL error or missing database */ 421 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 422 #define SQLITE_PERM 3 /* Access permission denied */ 423 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 424 #define SQLITE_BUSY 5 /* The database file is locked */ 425 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 426 #define SQLITE_NOMEM 7 /* A malloc() failed */ 427 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 428 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 429 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 430 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 431 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 432 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 433 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 434 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 435 #define SQLITE_EMPTY 16 /* Database is empty */ 436 #define SQLITE_SCHEMA 17 /* The database schema changed */ 437 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 438 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 439 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 440 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 441 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 442 #define SQLITE_AUTH 23 /* Authorization denied */ 443 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 444 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 445 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 446 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 447 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 448 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 449 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 450 /* end-of-error-codes */ 451 452 /* 453 ** CAPI3REF: Extended Result Codes 454 ** KEYWORDS: {extended result code definitions} 455 ** 456 ** In its default configuration, SQLite API routines return one of 30 integer 457 ** [result codes]. However, experience has shown that many of 458 ** these result codes are too coarse-grained. They do not provide as 459 ** much information about problems as programmers might like. In an effort to 460 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 461 ** and later) include 462 ** support for additional result codes that provide more detailed information 463 ** about errors. These [extended result codes] are enabled or disabled 464 ** on a per database connection basis using the 465 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 466 ** the most recent error can be obtained using 467 ** [sqlite3_extended_errcode()]. 468 */ 469 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 470 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 471 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 472 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 473 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 474 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 475 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 476 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 477 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 478 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 479 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 480 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 481 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 482 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 483 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 484 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 485 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 486 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 487 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 488 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 489 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 490 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 491 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 492 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 493 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 494 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 495 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 496 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 497 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 498 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 499 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 500 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 501 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 502 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 503 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 504 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 505 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 506 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 507 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 508 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 509 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 510 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 511 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 512 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 513 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 514 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 515 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 516 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 517 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 518 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 519 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 520 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 521 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 522 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 523 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 524 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 525 526 /* 527 ** CAPI3REF: Flags For File Open Operations 528 ** 529 ** These bit values are intended for use in the 530 ** 3rd parameter to the [sqlite3_open_v2()] interface and 531 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 532 */ 533 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 534 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 535 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 536 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 537 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 538 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 539 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 540 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 541 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 542 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 543 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 544 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 545 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 546 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 547 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 548 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 549 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 550 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 551 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 552 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 553 554 /* Reserved: 0x00F00000 */ 555 556 /* 557 ** CAPI3REF: Device Characteristics 558 ** 559 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 560 ** object returns an integer which is a vector of these 561 ** bit values expressing I/O characteristics of the mass storage 562 ** device that holds the file that the [sqlite3_io_methods] 563 ** refers to. 564 ** 565 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 566 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 567 ** mean that writes of blocks that are nnn bytes in size and 568 ** are aligned to an address which is an integer multiple of 569 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 570 ** that when data is appended to a file, the data is appended 571 ** first then the size of the file is extended, never the other 572 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 573 ** information is written to disk in the same order as calls 574 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 575 ** after reboot following a crash or power loss, the only bytes in a 576 ** file that were written at the application level might have changed 577 ** and that adjacent bytes, even bytes within the same sector are 578 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 579 ** flag indicates that a file cannot be deleted when open. The 580 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 581 ** read-only media and cannot be changed even by processes with 582 ** elevated privileges. 583 */ 584 #define SQLITE_IOCAP_ATOMIC 0x00000001 585 #define SQLITE_IOCAP_ATOMIC512 0x00000002 586 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 587 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 588 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 589 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 590 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 591 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 592 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 593 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 594 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 595 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 596 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 597 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 598 599 /* 600 ** CAPI3REF: File Locking Levels 601 ** 602 ** SQLite uses one of these integer values as the second 603 ** argument to calls it makes to the xLock() and xUnlock() methods 604 ** of an [sqlite3_io_methods] object. 605 */ 606 #define SQLITE_LOCK_NONE 0 607 #define SQLITE_LOCK_SHARED 1 608 #define SQLITE_LOCK_RESERVED 2 609 #define SQLITE_LOCK_PENDING 3 610 #define SQLITE_LOCK_EXCLUSIVE 4 611 612 /* 613 ** CAPI3REF: Synchronization Type Flags 614 ** 615 ** When SQLite invokes the xSync() method of an 616 ** [sqlite3_io_methods] object it uses a combination of 617 ** these integer values as the second argument. 618 ** 619 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 620 ** sync operation only needs to flush data to mass storage. Inode 621 ** information need not be flushed. If the lower four bits of the flag 622 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 623 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 624 ** to use Mac OS X style fullsync instead of fsync(). 625 ** 626 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 627 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 628 ** settings. The [synchronous pragma] determines when calls to the 629 ** xSync VFS method occur and applies uniformly across all platforms. 630 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 631 ** energetic or rigorous or forceful the sync operations are and 632 ** only make a difference on Mac OSX for the default SQLite code. 633 ** (Third-party VFS implementations might also make the distinction 634 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 635 ** operating systems natively supported by SQLite, only Mac OSX 636 ** cares about the difference.) 637 */ 638 #define SQLITE_SYNC_NORMAL 0x00002 639 #define SQLITE_SYNC_FULL 0x00003 640 #define SQLITE_SYNC_DATAONLY 0x00010 641 642 /* 643 ** CAPI3REF: OS Interface Open File Handle 644 ** 645 ** An [sqlite3_file] object represents an open file in the 646 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 647 ** implementations will 648 ** want to subclass this object by appending additional fields 649 ** for their own use. The pMethods entry is a pointer to an 650 ** [sqlite3_io_methods] object that defines methods for performing 651 ** I/O operations on the open file. 652 */ 653 typedef struct sqlite3_file sqlite3_file; 654 struct sqlite3_file { 655 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 656 }; 657 658 /* 659 ** CAPI3REF: OS Interface File Virtual Methods Object 660 ** 661 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 662 ** [sqlite3_file] object (or, more commonly, a subclass of the 663 ** [sqlite3_file] object) with a pointer to an instance of this object. 664 ** This object defines the methods used to perform various operations 665 ** against the open file represented by the [sqlite3_file] object. 666 ** 667 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 668 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 669 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 670 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 671 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 672 ** to NULL. 673 ** 674 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 675 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 676 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 677 ** flag may be ORed in to indicate that only the data of the file 678 ** and not its inode needs to be synced. 679 ** 680 ** The integer values to xLock() and xUnlock() are one of 681 ** <ul> 682 ** <li> [SQLITE_LOCK_NONE], 683 ** <li> [SQLITE_LOCK_SHARED], 684 ** <li> [SQLITE_LOCK_RESERVED], 685 ** <li> [SQLITE_LOCK_PENDING], or 686 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 687 ** </ul> 688 ** xLock() increases the lock. xUnlock() decreases the lock. 689 ** The xCheckReservedLock() method checks whether any database connection, 690 ** either in this process or in some other process, is holding a RESERVED, 691 ** PENDING, or EXCLUSIVE lock on the file. It returns true 692 ** if such a lock exists and false otherwise. 693 ** 694 ** The xFileControl() method is a generic interface that allows custom 695 ** VFS implementations to directly control an open file using the 696 ** [sqlite3_file_control()] interface. The second "op" argument is an 697 ** integer opcode. The third argument is a generic pointer intended to 698 ** point to a structure that may contain arguments or space in which to 699 ** write return values. Potential uses for xFileControl() might be 700 ** functions to enable blocking locks with timeouts, to change the 701 ** locking strategy (for example to use dot-file locks), to inquire 702 ** about the status of a lock, or to break stale locks. The SQLite 703 ** core reserves all opcodes less than 100 for its own use. 704 ** A [file control opcodes | list of opcodes] less than 100 is available. 705 ** Applications that define a custom xFileControl method should use opcodes 706 ** greater than 100 to avoid conflicts. VFS implementations should 707 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 708 ** recognize. 709 ** 710 ** The xSectorSize() method returns the sector size of the 711 ** device that underlies the file. The sector size is the 712 ** minimum write that can be performed without disturbing 713 ** other bytes in the file. The xDeviceCharacteristics() 714 ** method returns a bit vector describing behaviors of the 715 ** underlying device: 716 ** 717 ** <ul> 718 ** <li> [SQLITE_IOCAP_ATOMIC] 719 ** <li> [SQLITE_IOCAP_ATOMIC512] 720 ** <li> [SQLITE_IOCAP_ATOMIC1K] 721 ** <li> [SQLITE_IOCAP_ATOMIC2K] 722 ** <li> [SQLITE_IOCAP_ATOMIC4K] 723 ** <li> [SQLITE_IOCAP_ATOMIC8K] 724 ** <li> [SQLITE_IOCAP_ATOMIC16K] 725 ** <li> [SQLITE_IOCAP_ATOMIC32K] 726 ** <li> [SQLITE_IOCAP_ATOMIC64K] 727 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 728 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 729 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 730 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 731 ** <li> [SQLITE_IOCAP_IMMUTABLE] 732 ** </ul> 733 ** 734 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 735 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 736 ** mean that writes of blocks that are nnn bytes in size and 737 ** are aligned to an address which is an integer multiple of 738 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 739 ** that when data is appended to a file, the data is appended 740 ** first then the size of the file is extended, never the other 741 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 742 ** information is written to disk in the same order as calls 743 ** to xWrite(). 744 ** 745 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 746 ** in the unread portions of the buffer with zeros. A VFS that 747 ** fails to zero-fill short reads might seem to work. However, 748 ** failure to zero-fill short reads will eventually lead to 749 ** database corruption. 750 */ 751 typedef struct sqlite3_io_methods sqlite3_io_methods; 752 struct sqlite3_io_methods { 753 int iVersion; 754 int (*xClose)(sqlite3_file*); 755 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 756 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 757 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 758 int (*xSync)(sqlite3_file*, int flags); 759 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 760 int (*xLock)(sqlite3_file*, int); 761 int (*xUnlock)(sqlite3_file*, int); 762 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 763 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 764 int (*xSectorSize)(sqlite3_file*); 765 int (*xDeviceCharacteristics)(sqlite3_file*); 766 /* Methods above are valid for version 1 */ 767 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 768 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 769 void (*xShmBarrier)(sqlite3_file*); 770 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 771 /* Methods above are valid for version 2 */ 772 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 773 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 774 /* Methods above are valid for version 3 */ 775 /* Additional methods may be added in future releases */ 776 }; 777 778 /* 779 ** CAPI3REF: Standard File Control Opcodes 780 ** KEYWORDS: {file control opcodes} {file control opcode} 781 ** 782 ** These integer constants are opcodes for the xFileControl method 783 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 784 ** interface. 785 ** 786 ** <ul> 787 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 788 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 789 ** opcode causes the xFileControl method to write the current state of 790 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 791 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 792 ** into an integer that the pArg argument points to. This capability 793 ** is used during testing and is only available when the SQLITE_TEST 794 ** compile-time option is used. 795 ** 796 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 797 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 798 ** layer a hint of how large the database file will grow to be during the 799 ** current transaction. This hint is not guaranteed to be accurate but it 800 ** is often close. The underlying VFS might choose to preallocate database 801 ** file space based on this hint in order to help writes to the database 802 ** file run faster. 803 ** 804 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 805 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 806 ** extends and truncates the database file in chunks of a size specified 807 ** by the user. The fourth argument to [sqlite3_file_control()] should 808 ** point to an integer (type int) containing the new chunk-size to use 809 ** for the nominated database. Allocating database file space in large 810 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 811 ** improve performance on some systems. 812 ** 813 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 814 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 815 ** to the [sqlite3_file] object associated with a particular database 816 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 817 ** 818 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 819 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 820 ** to the [sqlite3_file] object associated with the journal file (either 821 ** the [rollback journal] or the [write-ahead log]) for a particular database 822 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 823 ** 824 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 825 ** No longer in use. 826 ** 827 ** <li>[[SQLITE_FCNTL_SYNC]] 828 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 829 ** sent to the VFS immediately before the xSync method is invoked on a 830 ** database file descriptor. Or, if the xSync method is not invoked 831 ** because the user has configured SQLite with 832 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 833 ** of the xSync method. In most cases, the pointer argument passed with 834 ** this file-control is NULL. However, if the database file is being synced 835 ** as part of a multi-database commit, the argument points to a nul-terminated 836 ** string containing the transactions master-journal file name. VFSes that 837 ** do not need this signal should silently ignore this opcode. Applications 838 ** should not call [sqlite3_file_control()] with this opcode as doing so may 839 ** disrupt the operation of the specialized VFSes that do require it. 840 ** 841 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 842 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 843 ** and sent to the VFS after a transaction has been committed immediately 844 ** but before the database is unlocked. VFSes that do not need this signal 845 ** should silently ignore this opcode. Applications should not call 846 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 847 ** operation of the specialized VFSes that do require it. 848 ** 849 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 850 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 851 ** retry counts and intervals for certain disk I/O operations for the 852 ** windows [VFS] in order to provide robustness in the presence of 853 ** anti-virus programs. By default, the windows VFS will retry file read, 854 ** file write, and file delete operations up to 10 times, with a delay 855 ** of 25 milliseconds before the first retry and with the delay increasing 856 ** by an additional 25 milliseconds with each subsequent retry. This 857 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 858 ** to be adjusted. The values are changed for all database connections 859 ** within the same process. The argument is a pointer to an array of two 860 ** integers where the first integer i the new retry count and the second 861 ** integer is the delay. If either integer is negative, then the setting 862 ** is not changed but instead the prior value of that setting is written 863 ** into the array entry, allowing the current retry settings to be 864 ** interrogated. The zDbName parameter is ignored. 865 ** 866 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 867 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 868 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 869 ** write ahead log and shared memory files used for transaction control 870 ** are automatically deleted when the latest connection to the database 871 ** closes. Setting persistent WAL mode causes those files to persist after 872 ** close. Persisting the files is useful when other processes that do not 873 ** have write permission on the directory containing the database file want 874 ** to read the database file, as the WAL and shared memory files must exist 875 ** in order for the database to be readable. The fourth parameter to 876 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 877 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 878 ** WAL mode. If the integer is -1, then it is overwritten with the current 879 ** WAL persistence setting. 880 ** 881 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 882 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 883 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 884 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 885 ** xDeviceCharacteristics methods. The fourth parameter to 886 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 887 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 888 ** mode. If the integer is -1, then it is overwritten with the current 889 ** zero-damage mode setting. 890 ** 891 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 892 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 893 ** a write transaction to indicate that, unless it is rolled back for some 894 ** reason, the entire database file will be overwritten by the current 895 ** transaction. This is used by VACUUM operations. 896 ** 897 ** <li>[[SQLITE_FCNTL_VFSNAME]] 898 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 899 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 900 ** final bottom-level VFS are written into memory obtained from 901 ** [sqlite3_malloc()] and the result is stored in the char* variable 902 ** that the fourth parameter of [sqlite3_file_control()] points to. 903 ** The caller is responsible for freeing the memory when done. As with 904 ** all file-control actions, there is no guarantee that this will actually 905 ** do anything. Callers should initialize the char* variable to a NULL 906 ** pointer in case this file-control is not implemented. This file-control 907 ** is intended for diagnostic use only. 908 ** 909 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 910 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 911 ** [VFSes] currently in use. ^(The argument X in 912 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 913 ** of type "[sqlite3_vfs] **". This opcodes will set *X 914 ** to a pointer to the top-level VFS.)^ 915 ** ^When there are multiple VFS shims in the stack, this opcode finds the 916 ** upper-most shim only. 917 ** 918 ** <li>[[SQLITE_FCNTL_PRAGMA]] 919 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 920 ** file control is sent to the open [sqlite3_file] object corresponding 921 ** to the database file to which the pragma statement refers. ^The argument 922 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 923 ** pointers to strings (char**) in which the second element of the array 924 ** is the name of the pragma and the third element is the argument to the 925 ** pragma or NULL if the pragma has no argument. ^The handler for an 926 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 927 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 928 ** or the equivalent and that string will become the result of the pragma or 929 ** the error message if the pragma fails. ^If the 930 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 931 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 932 ** file control returns [SQLITE_OK], then the parser assumes that the 933 ** VFS has handled the PRAGMA itself and the parser generates a no-op 934 ** prepared statement if result string is NULL, or that returns a copy 935 ** of the result string if the string is non-NULL. 936 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 937 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 938 ** that the VFS encountered an error while handling the [PRAGMA] and the 939 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 940 ** file control occurs at the beginning of pragma statement analysis and so 941 ** it is able to override built-in [PRAGMA] statements. 942 ** 943 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 944 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 945 ** file-control may be invoked by SQLite on the database file handle 946 ** shortly after it is opened in order to provide a custom VFS with access 947 ** to the connections busy-handler callback. The argument is of type (void **) 948 ** - an array of two (void *) values. The first (void *) actually points 949 ** to a function of type (int (*)(void *)). In order to invoke the connections 950 ** busy-handler, this function should be invoked with the second (void *) in 951 ** the array as the only argument. If it returns non-zero, then the operation 952 ** should be retried. If it returns zero, the custom VFS should abandon the 953 ** current operation. 954 ** 955 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 956 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 957 ** to have SQLite generate a 958 ** temporary filename using the same algorithm that is followed to generate 959 ** temporary filenames for TEMP tables and other internal uses. The 960 ** argument should be a char** which will be filled with the filename 961 ** written into memory obtained from [sqlite3_malloc()]. The caller should 962 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 963 ** 964 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 965 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 966 ** maximum number of bytes that will be used for memory-mapped I/O. 967 ** The argument is a pointer to a value of type sqlite3_int64 that 968 ** is an advisory maximum number of bytes in the file to memory map. The 969 ** pointer is overwritten with the old value. The limit is not changed if 970 ** the value originally pointed to is negative, and so the current limit 971 ** can be queried by passing in a pointer to a negative number. This 972 ** file-control is used internally to implement [PRAGMA mmap_size]. 973 ** 974 ** <li>[[SQLITE_FCNTL_TRACE]] 975 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 976 ** to the VFS about what the higher layers of the SQLite stack are doing. 977 ** This file control is used by some VFS activity tracing [shims]. 978 ** The argument is a zero-terminated string. Higher layers in the 979 ** SQLite stack may generate instances of this file control if 980 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 981 ** 982 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 983 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 984 ** pointer to an integer and it writes a boolean into that integer depending 985 ** on whether or not the file has been renamed, moved, or deleted since it 986 ** was first opened. 987 ** 988 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 989 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 990 ** underlying native file handle associated with a file handle. This file 991 ** control interprets its argument as a pointer to a native file handle and 992 ** writes the resulting value there. 993 ** 994 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 995 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 996 ** opcode causes the xFileControl method to swap the file handle with the one 997 ** pointed to by the pArg argument. This capability is used during testing 998 ** and only needs to be supported when SQLITE_TEST is defined. 999 ** 1000 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1001 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1002 ** be advantageous to block on the next WAL lock if the lock is not immediately 1003 ** available. The WAL subsystem issues this signal during rare 1004 ** circumstances in order to fix a problem with priority inversion. 1005 ** Applications should <em>not</em> use this file-control. 1006 ** 1007 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1008 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1009 ** VFS should return SQLITE_NOTFOUND for this opcode. 1010 ** 1011 ** <li>[[SQLITE_FCNTL_RBU]] 1012 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1013 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1014 ** this opcode. 1015 ** </ul> 1016 */ 1017 #define SQLITE_FCNTL_LOCKSTATE 1 1018 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1019 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1020 #define SQLITE_FCNTL_LAST_ERRNO 4 1021 #define SQLITE_FCNTL_SIZE_HINT 5 1022 #define SQLITE_FCNTL_CHUNK_SIZE 6 1023 #define SQLITE_FCNTL_FILE_POINTER 7 1024 #define SQLITE_FCNTL_SYNC_OMITTED 8 1025 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1026 #define SQLITE_FCNTL_PERSIST_WAL 10 1027 #define SQLITE_FCNTL_OVERWRITE 11 1028 #define SQLITE_FCNTL_VFSNAME 12 1029 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1030 #define SQLITE_FCNTL_PRAGMA 14 1031 #define SQLITE_FCNTL_BUSYHANDLER 15 1032 #define SQLITE_FCNTL_TEMPFILENAME 16 1033 #define SQLITE_FCNTL_MMAP_SIZE 18 1034 #define SQLITE_FCNTL_TRACE 19 1035 #define SQLITE_FCNTL_HAS_MOVED 20 1036 #define SQLITE_FCNTL_SYNC 21 1037 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1038 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1039 #define SQLITE_FCNTL_WAL_BLOCK 24 1040 #define SQLITE_FCNTL_ZIPVFS 25 1041 #define SQLITE_FCNTL_RBU 26 1042 #define SQLITE_FCNTL_VFS_POINTER 27 1043 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1044 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1045 #define SQLITE_FCNTL_PDB 30 1046 1047 /* deprecated names */ 1048 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1049 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1050 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1051 1052 1053 /* 1054 ** CAPI3REF: Mutex Handle 1055 ** 1056 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1057 ** abstract type for a mutex object. The SQLite core never looks 1058 ** at the internal representation of an [sqlite3_mutex]. It only 1059 ** deals with pointers to the [sqlite3_mutex] object. 1060 ** 1061 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1062 */ 1063 typedef struct sqlite3_mutex sqlite3_mutex; 1064 1065 /* 1066 ** CAPI3REF: Loadable Extension Thunk 1067 ** 1068 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1069 ** the third parameter to entry points of [loadable extensions]. This 1070 ** structure must be typedefed in order to work around compiler warnings 1071 ** on some platforms. 1072 */ 1073 typedef struct sqlite3_api_routines sqlite3_api_routines; 1074 1075 /* 1076 ** CAPI3REF: OS Interface Object 1077 ** 1078 ** An instance of the sqlite3_vfs object defines the interface between 1079 ** the SQLite core and the underlying operating system. The "vfs" 1080 ** in the name of the object stands for "virtual file system". See 1081 ** the [VFS | VFS documentation] for further information. 1082 ** 1083 ** The value of the iVersion field is initially 1 but may be larger in 1084 ** future versions of SQLite. Additional fields may be appended to this 1085 ** object when the iVersion value is increased. Note that the structure 1086 ** of the sqlite3_vfs object changes in the transaction between 1087 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1088 ** modified. 1089 ** 1090 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1091 ** structure used by this VFS. mxPathname is the maximum length of 1092 ** a pathname in this VFS. 1093 ** 1094 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1095 ** the pNext pointer. The [sqlite3_vfs_register()] 1096 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1097 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1098 ** searches the list. Neither the application code nor the VFS 1099 ** implementation should use the pNext pointer. 1100 ** 1101 ** The pNext field is the only field in the sqlite3_vfs 1102 ** structure that SQLite will ever modify. SQLite will only access 1103 ** or modify this field while holding a particular static mutex. 1104 ** The application should never modify anything within the sqlite3_vfs 1105 ** object once the object has been registered. 1106 ** 1107 ** The zName field holds the name of the VFS module. The name must 1108 ** be unique across all VFS modules. 1109 ** 1110 ** [[sqlite3_vfs.xOpen]] 1111 ** ^SQLite guarantees that the zFilename parameter to xOpen 1112 ** is either a NULL pointer or string obtained 1113 ** from xFullPathname() with an optional suffix added. 1114 ** ^If a suffix is added to the zFilename parameter, it will 1115 ** consist of a single "-" character followed by no more than 1116 ** 11 alphanumeric and/or "-" characters. 1117 ** ^SQLite further guarantees that 1118 ** the string will be valid and unchanged until xClose() is 1119 ** called. Because of the previous sentence, 1120 ** the [sqlite3_file] can safely store a pointer to the 1121 ** filename if it needs to remember the filename for some reason. 1122 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1123 ** must invent its own temporary name for the file. ^Whenever the 1124 ** xFilename parameter is NULL it will also be the case that the 1125 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1126 ** 1127 ** The flags argument to xOpen() includes all bits set in 1128 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1129 ** or [sqlite3_open16()] is used, then flags includes at least 1130 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1131 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1132 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1133 ** 1134 ** ^(SQLite will also add one of the following flags to the xOpen() 1135 ** call, depending on the object being opened: 1136 ** 1137 ** <ul> 1138 ** <li> [SQLITE_OPEN_MAIN_DB] 1139 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1140 ** <li> [SQLITE_OPEN_TEMP_DB] 1141 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1142 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1143 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1144 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1145 ** <li> [SQLITE_OPEN_WAL] 1146 ** </ul>)^ 1147 ** 1148 ** The file I/O implementation can use the object type flags to 1149 ** change the way it deals with files. For example, an application 1150 ** that does not care about crash recovery or rollback might make 1151 ** the open of a journal file a no-op. Writes to this journal would 1152 ** also be no-ops, and any attempt to read the journal would return 1153 ** SQLITE_IOERR. Or the implementation might recognize that a database 1154 ** file will be doing page-aligned sector reads and writes in a random 1155 ** order and set up its I/O subsystem accordingly. 1156 ** 1157 ** SQLite might also add one of the following flags to the xOpen method: 1158 ** 1159 ** <ul> 1160 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1161 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1162 ** </ul> 1163 ** 1164 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1165 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1166 ** will be set for TEMP databases and their journals, transient 1167 ** databases, and subjournals. 1168 ** 1169 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1170 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1171 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1172 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1173 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1174 ** be created, and that it is an error if it already exists. 1175 ** It is <i>not</i> used to indicate the file should be opened 1176 ** for exclusive access. 1177 ** 1178 ** ^At least szOsFile bytes of memory are allocated by SQLite 1179 ** to hold the [sqlite3_file] structure passed as the third 1180 ** argument to xOpen. The xOpen method does not have to 1181 ** allocate the structure; it should just fill it in. Note that 1182 ** the xOpen method must set the sqlite3_file.pMethods to either 1183 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1184 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1185 ** element will be valid after xOpen returns regardless of the success 1186 ** or failure of the xOpen call. 1187 ** 1188 ** [[sqlite3_vfs.xAccess]] 1189 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1190 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1191 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1192 ** to test whether a file is at least readable. The file can be a 1193 ** directory. 1194 ** 1195 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1196 ** output buffer xFullPathname. The exact size of the output buffer 1197 ** is also passed as a parameter to both methods. If the output buffer 1198 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1199 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1200 ** to prevent this by setting mxPathname to a sufficiently large value. 1201 ** 1202 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1203 ** interfaces are not strictly a part of the filesystem, but they are 1204 ** included in the VFS structure for completeness. 1205 ** The xRandomness() function attempts to return nBytes bytes 1206 ** of good-quality randomness into zOut. The return value is 1207 ** the actual number of bytes of randomness obtained. 1208 ** The xSleep() method causes the calling thread to sleep for at 1209 ** least the number of microseconds given. ^The xCurrentTime() 1210 ** method returns a Julian Day Number for the current date and time as 1211 ** a floating point value. 1212 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1213 ** Day Number multiplied by 86400000 (the number of milliseconds in 1214 ** a 24-hour day). 1215 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1216 ** date and time if that method is available (if iVersion is 2 or 1217 ** greater and the function pointer is not NULL) and will fall back 1218 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1219 ** 1220 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1221 ** are not used by the SQLite core. These optional interfaces are provided 1222 ** by some VFSes to facilitate testing of the VFS code. By overriding 1223 ** system calls with functions under its control, a test program can 1224 ** simulate faults and error conditions that would otherwise be difficult 1225 ** or impossible to induce. The set of system calls that can be overridden 1226 ** varies from one VFS to another, and from one version of the same VFS to the 1227 ** next. Applications that use these interfaces must be prepared for any 1228 ** or all of these interfaces to be NULL or for their behavior to change 1229 ** from one release to the next. Applications must not attempt to access 1230 ** any of these methods if the iVersion of the VFS is less than 3. 1231 */ 1232 typedef struct sqlite3_vfs sqlite3_vfs; 1233 typedef void (*sqlite3_syscall_ptr)(void); 1234 struct sqlite3_vfs { 1235 int iVersion; /* Structure version number (currently 3) */ 1236 int szOsFile; /* Size of subclassed sqlite3_file */ 1237 int mxPathname; /* Maximum file pathname length */ 1238 sqlite3_vfs *pNext; /* Next registered VFS */ 1239 const char *zName; /* Name of this virtual file system */ 1240 void *pAppData; /* Pointer to application-specific data */ 1241 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1242 int flags, int *pOutFlags); 1243 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1244 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1245 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1246 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1247 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1248 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1249 void (*xDlClose)(sqlite3_vfs*, void*); 1250 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1251 int (*xSleep)(sqlite3_vfs*, int microseconds); 1252 int (*xCurrentTime)(sqlite3_vfs*, double*); 1253 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1254 /* 1255 ** The methods above are in version 1 of the sqlite_vfs object 1256 ** definition. Those that follow are added in version 2 or later 1257 */ 1258 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1259 /* 1260 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1261 ** Those below are for version 3 and greater. 1262 */ 1263 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1264 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1265 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1266 /* 1267 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1268 ** New fields may be appended in future versions. The iVersion 1269 ** value will increment whenever this happens. 1270 */ 1271 }; 1272 1273 /* 1274 ** CAPI3REF: Flags for the xAccess VFS method 1275 ** 1276 ** These integer constants can be used as the third parameter to 1277 ** the xAccess method of an [sqlite3_vfs] object. They determine 1278 ** what kind of permissions the xAccess method is looking for. 1279 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1280 ** simply checks whether the file exists. 1281 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1282 ** checks whether the named directory is both readable and writable 1283 ** (in other words, if files can be added, removed, and renamed within 1284 ** the directory). 1285 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1286 ** [temp_store_directory pragma], though this could change in a future 1287 ** release of SQLite. 1288 ** With SQLITE_ACCESS_READ, the xAccess method 1289 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1290 ** currently unused, though it might be used in a future release of 1291 ** SQLite. 1292 */ 1293 #define SQLITE_ACCESS_EXISTS 0 1294 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1295 #define SQLITE_ACCESS_READ 2 /* Unused */ 1296 1297 /* 1298 ** CAPI3REF: Flags for the xShmLock VFS method 1299 ** 1300 ** These integer constants define the various locking operations 1301 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1302 ** following are the only legal combinations of flags to the 1303 ** xShmLock method: 1304 ** 1305 ** <ul> 1306 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1307 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1308 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1309 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1310 ** </ul> 1311 ** 1312 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1313 ** was given on the corresponding lock. 1314 ** 1315 ** The xShmLock method can transition between unlocked and SHARED or 1316 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1317 ** and EXCLUSIVE. 1318 */ 1319 #define SQLITE_SHM_UNLOCK 1 1320 #define SQLITE_SHM_LOCK 2 1321 #define SQLITE_SHM_SHARED 4 1322 #define SQLITE_SHM_EXCLUSIVE 8 1323 1324 /* 1325 ** CAPI3REF: Maximum xShmLock index 1326 ** 1327 ** The xShmLock method on [sqlite3_io_methods] may use values 1328 ** between 0 and this upper bound as its "offset" argument. 1329 ** The SQLite core will never attempt to acquire or release a 1330 ** lock outside of this range 1331 */ 1332 #define SQLITE_SHM_NLOCK 8 1333 1334 1335 /* 1336 ** CAPI3REF: Initialize The SQLite Library 1337 ** 1338 ** ^The sqlite3_initialize() routine initializes the 1339 ** SQLite library. ^The sqlite3_shutdown() routine 1340 ** deallocates any resources that were allocated by sqlite3_initialize(). 1341 ** These routines are designed to aid in process initialization and 1342 ** shutdown on embedded systems. Workstation applications using 1343 ** SQLite normally do not need to invoke either of these routines. 1344 ** 1345 ** A call to sqlite3_initialize() is an "effective" call if it is 1346 ** the first time sqlite3_initialize() is invoked during the lifetime of 1347 ** the process, or if it is the first time sqlite3_initialize() is invoked 1348 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1349 ** of sqlite3_initialize() does any initialization. All other calls 1350 ** are harmless no-ops.)^ 1351 ** 1352 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1353 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1354 ** an effective call to sqlite3_shutdown() does any deinitialization. 1355 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1356 ** 1357 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1358 ** is not. The sqlite3_shutdown() interface must only be called from a 1359 ** single thread. All open [database connections] must be closed and all 1360 ** other SQLite resources must be deallocated prior to invoking 1361 ** sqlite3_shutdown(). 1362 ** 1363 ** Among other things, ^sqlite3_initialize() will invoke 1364 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1365 ** will invoke sqlite3_os_end(). 1366 ** 1367 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1368 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1369 ** the library (perhaps it is unable to allocate a needed resource such 1370 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1371 ** 1372 ** ^The sqlite3_initialize() routine is called internally by many other 1373 ** SQLite interfaces so that an application usually does not need to 1374 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1375 ** calls sqlite3_initialize() so the SQLite library will be automatically 1376 ** initialized when [sqlite3_open()] is called if it has not be initialized 1377 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1378 ** compile-time option, then the automatic calls to sqlite3_initialize() 1379 ** are omitted and the application must call sqlite3_initialize() directly 1380 ** prior to using any other SQLite interface. For maximum portability, 1381 ** it is recommended that applications always invoke sqlite3_initialize() 1382 ** directly prior to using any other SQLite interface. Future releases 1383 ** of SQLite may require this. In other words, the behavior exhibited 1384 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1385 ** default behavior in some future release of SQLite. 1386 ** 1387 ** The sqlite3_os_init() routine does operating-system specific 1388 ** initialization of the SQLite library. The sqlite3_os_end() 1389 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1390 ** performed by these routines include allocation or deallocation 1391 ** of static resources, initialization of global variables, 1392 ** setting up a default [sqlite3_vfs] module, or setting up 1393 ** a default configuration using [sqlite3_config()]. 1394 ** 1395 ** The application should never invoke either sqlite3_os_init() 1396 ** or sqlite3_os_end() directly. The application should only invoke 1397 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1398 ** interface is called automatically by sqlite3_initialize() and 1399 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1400 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1401 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1402 ** When [custom builds | built for other platforms] 1403 ** (using the [SQLITE_OS_OTHER=1] compile-time 1404 ** option) the application must supply a suitable implementation for 1405 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1406 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1407 ** must return [SQLITE_OK] on success and some other [error code] upon 1408 ** failure. 1409 */ 1410 SQLITE_API int sqlite3_initialize(void); 1411 SQLITE_API int sqlite3_shutdown(void); 1412 SQLITE_API int sqlite3_os_init(void); 1413 SQLITE_API int sqlite3_os_end(void); 1414 1415 /* 1416 ** CAPI3REF: Configuring The SQLite Library 1417 ** 1418 ** The sqlite3_config() interface is used to make global configuration 1419 ** changes to SQLite in order to tune SQLite to the specific needs of 1420 ** the application. The default configuration is recommended for most 1421 ** applications and so this routine is usually not necessary. It is 1422 ** provided to support rare applications with unusual needs. 1423 ** 1424 ** <b>The sqlite3_config() interface is not threadsafe. The application 1425 ** must ensure that no other SQLite interfaces are invoked by other 1426 ** threads while sqlite3_config() is running.</b> 1427 ** 1428 ** The sqlite3_config() interface 1429 ** may only be invoked prior to library initialization using 1430 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1431 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1432 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1433 ** Note, however, that ^sqlite3_config() can be called as part of the 1434 ** implementation of an application-defined [sqlite3_os_init()]. 1435 ** 1436 ** The first argument to sqlite3_config() is an integer 1437 ** [configuration option] that determines 1438 ** what property of SQLite is to be configured. Subsequent arguments 1439 ** vary depending on the [configuration option] 1440 ** in the first argument. 1441 ** 1442 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1443 ** ^If the option is unknown or SQLite is unable to set the option 1444 ** then this routine returns a non-zero [error code]. 1445 */ 1446 SQLITE_API int sqlite3_config(int, ...); 1447 1448 /* 1449 ** CAPI3REF: Configure database connections 1450 ** METHOD: sqlite3 1451 ** 1452 ** The sqlite3_db_config() interface is used to make configuration 1453 ** changes to a [database connection]. The interface is similar to 1454 ** [sqlite3_config()] except that the changes apply to a single 1455 ** [database connection] (specified in the first argument). 1456 ** 1457 ** The second argument to sqlite3_db_config(D,V,...) is the 1458 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1459 ** that indicates what aspect of the [database connection] is being configured. 1460 ** Subsequent arguments vary depending on the configuration verb. 1461 ** 1462 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1463 ** the call is considered successful. 1464 */ 1465 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1466 1467 /* 1468 ** CAPI3REF: Memory Allocation Routines 1469 ** 1470 ** An instance of this object defines the interface between SQLite 1471 ** and low-level memory allocation routines. 1472 ** 1473 ** This object is used in only one place in the SQLite interface. 1474 ** A pointer to an instance of this object is the argument to 1475 ** [sqlite3_config()] when the configuration option is 1476 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1477 ** By creating an instance of this object 1478 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1479 ** during configuration, an application can specify an alternative 1480 ** memory allocation subsystem for SQLite to use for all of its 1481 ** dynamic memory needs. 1482 ** 1483 ** Note that SQLite comes with several [built-in memory allocators] 1484 ** that are perfectly adequate for the overwhelming majority of applications 1485 ** and that this object is only useful to a tiny minority of applications 1486 ** with specialized memory allocation requirements. This object is 1487 ** also used during testing of SQLite in order to specify an alternative 1488 ** memory allocator that simulates memory out-of-memory conditions in 1489 ** order to verify that SQLite recovers gracefully from such 1490 ** conditions. 1491 ** 1492 ** The xMalloc, xRealloc, and xFree methods must work like the 1493 ** malloc(), realloc() and free() functions from the standard C library. 1494 ** ^SQLite guarantees that the second argument to 1495 ** xRealloc is always a value returned by a prior call to xRoundup. 1496 ** 1497 ** xSize should return the allocated size of a memory allocation 1498 ** previously obtained from xMalloc or xRealloc. The allocated size 1499 ** is always at least as big as the requested size but may be larger. 1500 ** 1501 ** The xRoundup method returns what would be the allocated size of 1502 ** a memory allocation given a particular requested size. Most memory 1503 ** allocators round up memory allocations at least to the next multiple 1504 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1505 ** Every memory allocation request coming in through [sqlite3_malloc()] 1506 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1507 ** that causes the corresponding memory allocation to fail. 1508 ** 1509 ** The xInit method initializes the memory allocator. For example, 1510 ** it might allocate any require mutexes or initialize internal data 1511 ** structures. The xShutdown method is invoked (indirectly) by 1512 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1513 ** by xInit. The pAppData pointer is used as the only parameter to 1514 ** xInit and xShutdown. 1515 ** 1516 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1517 ** the xInit method, so the xInit method need not be threadsafe. The 1518 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1519 ** not need to be threadsafe either. For all other methods, SQLite 1520 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1521 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1522 ** it is by default) and so the methods are automatically serialized. 1523 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1524 ** methods must be threadsafe or else make their own arrangements for 1525 ** serialization. 1526 ** 1527 ** SQLite will never invoke xInit() more than once without an intervening 1528 ** call to xShutdown(). 1529 */ 1530 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1531 struct sqlite3_mem_methods { 1532 void *(*xMalloc)(int); /* Memory allocation function */ 1533 void (*xFree)(void*); /* Free a prior allocation */ 1534 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1535 int (*xSize)(void*); /* Return the size of an allocation */ 1536 int (*xRoundup)(int); /* Round up request size to allocation size */ 1537 int (*xInit)(void*); /* Initialize the memory allocator */ 1538 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1539 void *pAppData; /* Argument to xInit() and xShutdown() */ 1540 }; 1541 1542 /* 1543 ** CAPI3REF: Configuration Options 1544 ** KEYWORDS: {configuration option} 1545 ** 1546 ** These constants are the available integer configuration options that 1547 ** can be passed as the first argument to the [sqlite3_config()] interface. 1548 ** 1549 ** New configuration options may be added in future releases of SQLite. 1550 ** Existing configuration options might be discontinued. Applications 1551 ** should check the return code from [sqlite3_config()] to make sure that 1552 ** the call worked. The [sqlite3_config()] interface will return a 1553 ** non-zero [error code] if a discontinued or unsupported configuration option 1554 ** is invoked. 1555 ** 1556 ** <dl> 1557 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1558 ** <dd>There are no arguments to this option. ^This option sets the 1559 ** [threading mode] to Single-thread. In other words, it disables 1560 ** all mutexing and puts SQLite into a mode where it can only be used 1561 ** by a single thread. ^If SQLite is compiled with 1562 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1563 ** it is not possible to change the [threading mode] from its default 1564 ** value of Single-thread and so [sqlite3_config()] will return 1565 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1566 ** configuration option.</dd> 1567 ** 1568 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1569 ** <dd>There are no arguments to this option. ^This option sets the 1570 ** [threading mode] to Multi-thread. In other words, it disables 1571 ** mutexing on [database connection] and [prepared statement] objects. 1572 ** The application is responsible for serializing access to 1573 ** [database connections] and [prepared statements]. But other mutexes 1574 ** are enabled so that SQLite will be safe to use in a multi-threaded 1575 ** environment as long as no two threads attempt to use the same 1576 ** [database connection] at the same time. ^If SQLite is compiled with 1577 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1578 ** it is not possible to set the Multi-thread [threading mode] and 1579 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1580 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1581 ** 1582 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1583 ** <dd>There are no arguments to this option. ^This option sets the 1584 ** [threading mode] to Serialized. In other words, this option enables 1585 ** all mutexes including the recursive 1586 ** mutexes on [database connection] and [prepared statement] objects. 1587 ** In this mode (which is the default when SQLite is compiled with 1588 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1589 ** to [database connections] and [prepared statements] so that the 1590 ** application is free to use the same [database connection] or the 1591 ** same [prepared statement] in different threads at the same time. 1592 ** ^If SQLite is compiled with 1593 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1594 ** it is not possible to set the Serialized [threading mode] and 1595 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1596 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1597 ** 1598 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1599 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1600 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1601 ** The argument specifies 1602 ** alternative low-level memory allocation routines to be used in place of 1603 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1604 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1605 ** before the [sqlite3_config()] call returns.</dd> 1606 ** 1607 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1608 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1609 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1610 ** The [sqlite3_mem_methods] 1611 ** structure is filled with the currently defined memory allocation routines.)^ 1612 ** This option can be used to overload the default memory allocation 1613 ** routines with a wrapper that simulations memory allocation failure or 1614 ** tracks memory usage, for example. </dd> 1615 ** 1616 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1617 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1618 ** interpreted as a boolean, which enables or disables the collection of 1619 ** memory allocation statistics. ^(When memory allocation statistics are 1620 ** disabled, the following SQLite interfaces become non-operational: 1621 ** <ul> 1622 ** <li> [sqlite3_memory_used()] 1623 ** <li> [sqlite3_memory_highwater()] 1624 ** <li> [sqlite3_soft_heap_limit64()] 1625 ** <li> [sqlite3_status64()] 1626 ** </ul>)^ 1627 ** ^Memory allocation statistics are enabled by default unless SQLite is 1628 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1629 ** allocation statistics are disabled by default. 1630 ** </dd> 1631 ** 1632 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1633 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1634 ** that SQLite can use for scratch memory. ^(There are three arguments 1635 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1636 ** aligned memory buffer from which the scratch allocations will be 1637 ** drawn, the size of each scratch allocation (sz), 1638 ** and the maximum number of scratch allocations (N).)^ 1639 ** The first argument must be a pointer to an 8-byte aligned buffer 1640 ** of at least sz*N bytes of memory. 1641 ** ^SQLite will not use more than one scratch buffers per thread. 1642 ** ^SQLite will never request a scratch buffer that is more than 6 1643 ** times the database page size. 1644 ** ^If SQLite needs needs additional 1645 ** scratch memory beyond what is provided by this configuration option, then 1646 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1647 ** ^When the application provides any amount of scratch memory using 1648 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1649 ** [sqlite3_malloc|heap allocations]. 1650 ** This can help [Robson proof|prevent memory allocation failures] due to heap 1651 ** fragmentation in low-memory embedded systems. 1652 ** </dd> 1653 ** 1654 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1655 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1656 ** that SQLite can use for the database page cache with the default page 1657 ** cache implementation. 1658 ** This configuration option is a no-op if an application-define page 1659 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1660 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1661 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1662 ** and the number of cache lines (N). 1663 ** The sz argument should be the size of the largest database page 1664 ** (a power of two between 512 and 65536) plus some extra bytes for each 1665 ** page header. ^The number of extra bytes needed by the page header 1666 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1667 ** ^It is harmless, apart from the wasted memory, 1668 ** for the sz parameter to be larger than necessary. The pMem 1669 ** argument must be either a NULL pointer or a pointer to an 8-byte 1670 ** aligned block of memory of at least sz*N bytes, otherwise 1671 ** subsequent behavior is undefined. 1672 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1673 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1674 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1675 ** is exhausted. 1676 ** ^If pMem is NULL and N is non-zero, then each database connection 1677 ** does an initial bulk allocation for page cache memory 1678 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1679 ** of -1024*N bytes if N is negative, . ^If additional 1680 ** page cache memory is needed beyond what is provided by the initial 1681 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1682 ** additional cache line. </dd> 1683 ** 1684 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1685 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1686 ** that SQLite will use for all of its dynamic memory allocation needs 1687 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1688 ** [SQLITE_CONFIG_PAGECACHE]. 1689 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1690 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1691 ** [SQLITE_ERROR] if invoked otherwise. 1692 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1693 ** An 8-byte aligned pointer to the memory, 1694 ** the number of bytes in the memory buffer, and the minimum allocation size. 1695 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1696 ** to using its default memory allocator (the system malloc() implementation), 1697 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1698 ** memory pointer is not NULL then the alternative memory 1699 ** allocator is engaged to handle all of SQLites memory allocation needs. 1700 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1701 ** boundary or subsequent behavior of SQLite will be undefined. 1702 ** The minimum allocation size is capped at 2**12. Reasonable values 1703 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1704 ** 1705 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1706 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1707 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1708 ** The argument specifies alternative low-level mutex routines to be used 1709 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1710 ** the content of the [sqlite3_mutex_methods] structure before the call to 1711 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1712 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1713 ** the entire mutexing subsystem is omitted from the build and hence calls to 1714 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1715 ** return [SQLITE_ERROR].</dd> 1716 ** 1717 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1718 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1719 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1720 ** [sqlite3_mutex_methods] 1721 ** structure is filled with the currently defined mutex routines.)^ 1722 ** This option can be used to overload the default mutex allocation 1723 ** routines with a wrapper used to track mutex usage for performance 1724 ** profiling or testing, for example. ^If SQLite is compiled with 1725 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1726 ** the entire mutexing subsystem is omitted from the build and hence calls to 1727 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1728 ** return [SQLITE_ERROR].</dd> 1729 ** 1730 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1731 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1732 ** the default size of lookaside memory on each [database connection]. 1733 ** The first argument is the 1734 ** size of each lookaside buffer slot and the second is the number of 1735 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1736 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1737 ** option to [sqlite3_db_config()] can be used to change the lookaside 1738 ** configuration on individual connections.)^ </dd> 1739 ** 1740 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1741 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1742 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1743 ** the interface to a custom page cache implementation.)^ 1744 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1745 ** 1746 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1747 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1748 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1749 ** the current page cache implementation into that object.)^ </dd> 1750 ** 1751 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1752 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1753 ** global [error log]. 1754 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1755 ** function with a call signature of void(*)(void*,int,const char*), 1756 ** and a pointer to void. ^If the function pointer is not NULL, it is 1757 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1758 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1759 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1760 ** passed through as the first parameter to the application-defined logger 1761 ** function whenever that function is invoked. ^The second parameter to 1762 ** the logger function is a copy of the first parameter to the corresponding 1763 ** [sqlite3_log()] call and is intended to be a [result code] or an 1764 ** [extended result code]. ^The third parameter passed to the logger is 1765 ** log message after formatting via [sqlite3_snprintf()]. 1766 ** The SQLite logging interface is not reentrant; the logger function 1767 ** supplied by the application must not invoke any SQLite interface. 1768 ** In a multi-threaded application, the application-defined logger 1769 ** function must be threadsafe. </dd> 1770 ** 1771 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1772 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1773 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1774 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1775 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1776 ** [sqlite3_open16()] or 1777 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1778 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1779 ** connection is opened. ^If it is globally disabled, filenames are 1780 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1781 ** database connection is opened. ^(By default, URI handling is globally 1782 ** disabled. The default value may be changed by compiling with the 1783 ** [SQLITE_USE_URI] symbol defined.)^ 1784 ** 1785 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1786 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1787 ** argument which is interpreted as a boolean in order to enable or disable 1788 ** the use of covering indices for full table scans in the query optimizer. 1789 ** ^The default setting is determined 1790 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1791 ** if that compile-time option is omitted. 1792 ** The ability to disable the use of covering indices for full table scans 1793 ** is because some incorrectly coded legacy applications might malfunction 1794 ** when the optimization is enabled. Providing the ability to 1795 ** disable the optimization allows the older, buggy application code to work 1796 ** without change even with newer versions of SQLite. 1797 ** 1798 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1799 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1800 ** <dd> These options are obsolete and should not be used by new code. 1801 ** They are retained for backwards compatibility but are now no-ops. 1802 ** </dd> 1803 ** 1804 ** [[SQLITE_CONFIG_SQLLOG]] 1805 ** <dt>SQLITE_CONFIG_SQLLOG 1806 ** <dd>This option is only available if sqlite is compiled with the 1807 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1808 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1809 ** The second should be of type (void*). The callback is invoked by the library 1810 ** in three separate circumstances, identified by the value passed as the 1811 ** fourth parameter. If the fourth parameter is 0, then the database connection 1812 ** passed as the second argument has just been opened. The third argument 1813 ** points to a buffer containing the name of the main database file. If the 1814 ** fourth parameter is 1, then the SQL statement that the third parameter 1815 ** points to has just been executed. Or, if the fourth parameter is 2, then 1816 ** the connection being passed as the second parameter is being closed. The 1817 ** third parameter is passed NULL In this case. An example of using this 1818 ** configuration option can be seen in the "test_sqllog.c" source file in 1819 ** the canonical SQLite source tree.</dd> 1820 ** 1821 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1822 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1823 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1824 ** that are the default mmap size limit (the default setting for 1825 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1826 ** ^The default setting can be overridden by each database connection using 1827 ** either the [PRAGMA mmap_size] command, or by using the 1828 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1829 ** will be silently truncated if necessary so that it does not exceed the 1830 ** compile-time maximum mmap size set by the 1831 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1832 ** ^If either argument to this option is negative, then that argument is 1833 ** changed to its compile-time default. 1834 ** 1835 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1836 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1837 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1838 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1839 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1840 ** that specifies the maximum size of the created heap. 1841 ** 1842 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1843 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1844 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1845 ** is a pointer to an integer and writes into that integer the number of extra 1846 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1847 ** The amount of extra space required can change depending on the compiler, 1848 ** target platform, and SQLite version. 1849 ** 1850 ** [[SQLITE_CONFIG_PMASZ]] 1851 ** <dt>SQLITE_CONFIG_PMASZ 1852 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1853 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1854 ** sorter to that integer. The default minimum PMA Size is set by the 1855 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1856 ** to help with sort operations when multithreaded sorting 1857 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1858 ** to be sorted exceeds the page size times the minimum of the 1859 ** [PRAGMA cache_size] setting and this value. 1860 ** 1861 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1862 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1863 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1864 ** becomes the [statement journal] spill-to-disk threshold. 1865 ** [Statement journals] are held in memory until their size (in bytes) 1866 ** exceeds this threshold, at which point they are written to disk. 1867 ** Or if the threshold is -1, statement journals are always held 1868 ** exclusively in memory. 1869 ** Since many statement journals never become large, setting the spill 1870 ** threshold to a value such as 64KiB can greatly reduce the amount of 1871 ** I/O required to support statement rollback. 1872 ** The default value for this setting is controlled by the 1873 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1874 ** </dl> 1875 */ 1876 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1877 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1878 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1879 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1880 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1881 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1882 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1883 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1884 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1885 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1886 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1887 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1888 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1889 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1890 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1891 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1892 #define SQLITE_CONFIG_URI 17 /* int */ 1893 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1894 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1895 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1896 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1897 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1898 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1899 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1900 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1901 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1902 1903 /* 1904 ** CAPI3REF: Database Connection Configuration Options 1905 ** 1906 ** These constants are the available integer configuration options that 1907 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1908 ** 1909 ** New configuration options may be added in future releases of SQLite. 1910 ** Existing configuration options might be discontinued. Applications 1911 ** should check the return code from [sqlite3_db_config()] to make sure that 1912 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1913 ** non-zero [error code] if a discontinued or unsupported configuration option 1914 ** is invoked. 1915 ** 1916 ** <dl> 1917 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1918 ** <dd> ^This option takes three additional arguments that determine the 1919 ** [lookaside memory allocator] configuration for the [database connection]. 1920 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1921 ** pointer to a memory buffer to use for lookaside memory. 1922 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1923 ** may be NULL in which case SQLite will allocate the 1924 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1925 ** size of each lookaside buffer slot. ^The third argument is the number of 1926 ** slots. The size of the buffer in the first argument must be greater than 1927 ** or equal to the product of the second and third arguments. The buffer 1928 ** must be aligned to an 8-byte boundary. ^If the second argument to 1929 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1930 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1931 ** configuration for a database connection can only be changed when that 1932 ** connection is not currently using lookaside memory, or in other words 1933 ** when the "current value" returned by 1934 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1935 ** Any attempt to change the lookaside memory configuration when lookaside 1936 ** memory is in use leaves the configuration unchanged and returns 1937 ** [SQLITE_BUSY].)^</dd> 1938 ** 1939 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1940 ** <dd> ^This option is used to enable or disable the enforcement of 1941 ** [foreign key constraints]. There should be two additional arguments. 1942 ** The first argument is an integer which is 0 to disable FK enforcement, 1943 ** positive to enable FK enforcement or negative to leave FK enforcement 1944 ** unchanged. The second parameter is a pointer to an integer into which 1945 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1946 ** following this call. The second parameter may be a NULL pointer, in 1947 ** which case the FK enforcement setting is not reported back. </dd> 1948 ** 1949 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1950 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1951 ** There should be two additional arguments. 1952 ** The first argument is an integer which is 0 to disable triggers, 1953 ** positive to enable triggers or negative to leave the setting unchanged. 1954 ** The second parameter is a pointer to an integer into which 1955 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1956 ** following this call. The second parameter may be a NULL pointer, in 1957 ** which case the trigger setting is not reported back. </dd> 1958 ** 1959 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1960 ** <dd> ^This option is used to enable or disable the two-argument 1961 ** version of the [fts3_tokenizer()] function which is part of the 1962 ** [FTS3] full-text search engine extension. 1963 ** There should be two additional arguments. 1964 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1965 ** positive to enable fts3_tokenizer() or negative to leave the setting 1966 ** unchanged. 1967 ** The second parameter is a pointer to an integer into which 1968 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1969 ** following this call. The second parameter may be a NULL pointer, in 1970 ** which case the new setting is not reported back. </dd> 1971 ** 1972 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 1973 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 1974 ** interface independently of the [load_extension()] SQL function. 1975 ** The [sqlite3_enable_load_extension()] API enables or disables both the 1976 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 1977 ** There should be two additional arguments. 1978 ** When the first argument to this interface is 1, then only the C-API is 1979 ** enabled and the SQL function remains disabled. If the first argument to 1980 ** this interface is 0, then both the C-API and the SQL function are disabled. 1981 ** If the first argument is -1, then no changes are made to state of either the 1982 ** C-API or the SQL function. 1983 ** The second parameter is a pointer to an integer into which 1984 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 1985 ** is disabled or enabled following this call. The second parameter may 1986 ** be a NULL pointer, in which case the new setting is not reported back. 1987 ** </dd> 1988 ** 1989 ** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 1990 ** <dd> ^This option is used to change the name of the "main" database 1991 ** schema. ^The sole argument is a pointer to a constant UTF8 string 1992 ** which will become the new schema name in place of "main". ^SQLite 1993 ** does not make a copy of the new main schema name string, so the application 1994 ** must ensure that the argument passed into this DBCONFIG option is unchanged 1995 ** until after the database connection closes. 1996 ** </dd> 1997 ** 1998 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 1999 ** <dd> Usually, when a database in wal mode is closed or detached from a 2000 ** database handle, SQLite checks if this will mean that there are now no 2001 ** connections at all to the database. If so, it performs a checkpoint 2002 ** operation before closing the connection. This option may be used to 2003 ** override this behaviour. The first parameter passed to this operation 2004 ** is an integer - non-zero to disable checkpoints-on-close, or zero (the 2005 ** default) to enable them. The second parameter is a pointer to an integer 2006 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2007 ** have been disabled - 0 if they are not disabled, 1 if they are. 2008 ** </dd> 2009 ** 2010 ** </dl> 2011 */ 2012 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2013 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2014 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2015 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2016 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2017 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2018 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2019 2020 2021 /* 2022 ** CAPI3REF: Enable Or Disable Extended Result Codes 2023 ** METHOD: sqlite3 2024 ** 2025 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2026 ** [extended result codes] feature of SQLite. ^The extended result 2027 ** codes are disabled by default for historical compatibility. 2028 */ 2029 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2030 2031 /* 2032 ** CAPI3REF: Last Insert Rowid 2033 ** METHOD: sqlite3 2034 ** 2035 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2036 ** has a unique 64-bit signed 2037 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2038 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2039 ** names are not also used by explicitly declared columns. ^If 2040 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2041 ** is another alias for the rowid. 2042 ** 2043 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2044 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2045 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2046 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2047 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2048 ** zero. 2049 ** 2050 ** As well as being set automatically as rows are inserted into database 2051 ** tables, the value returned by this function may be set explicitly by 2052 ** [sqlite3_set_last_insert_rowid()] 2053 ** 2054 ** Some virtual table implementations may INSERT rows into rowid tables as 2055 ** part of committing a transaction (e.g. to flush data accumulated in memory 2056 ** to disk). In this case subsequent calls to this function return the rowid 2057 ** associated with these internal INSERT operations, which leads to 2058 ** unintuitive results. Virtual table implementations that do write to rowid 2059 ** tables in this way can avoid this problem by restoring the original 2060 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2061 ** control to the user. 2062 ** 2063 ** ^(If an [INSERT] occurs within a trigger then this routine will 2064 ** return the [rowid] of the inserted row as long as the trigger is 2065 ** running. Once the trigger program ends, the value returned 2066 ** by this routine reverts to what it was before the trigger was fired.)^ 2067 ** 2068 ** ^An [INSERT] that fails due to a constraint violation is not a 2069 ** successful [INSERT] and does not change the value returned by this 2070 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2071 ** and INSERT OR ABORT make no changes to the return value of this 2072 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2073 ** encounters a constraint violation, it does not fail. The 2074 ** INSERT continues to completion after deleting rows that caused 2075 ** the constraint problem so INSERT OR REPLACE will always change 2076 ** the return value of this interface.)^ 2077 ** 2078 ** ^For the purposes of this routine, an [INSERT] is considered to 2079 ** be successful even if it is subsequently rolled back. 2080 ** 2081 ** This function is accessible to SQL statements via the 2082 ** [last_insert_rowid() SQL function]. 2083 ** 2084 ** If a separate thread performs a new [INSERT] on the same 2085 ** database connection while the [sqlite3_last_insert_rowid()] 2086 ** function is running and thus changes the last insert [rowid], 2087 ** then the value returned by [sqlite3_last_insert_rowid()] is 2088 ** unpredictable and might not equal either the old or the new 2089 ** last insert [rowid]. 2090 */ 2091 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2092 2093 /* 2094 ** CAPI3REF: Set the Last Insert Rowid value. 2095 ** METHOD: sqlite3 2096 ** 2097 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2098 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2099 ** without inserting a row into the database. 2100 */ 2101 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2102 2103 /* 2104 ** CAPI3REF: Count The Number Of Rows Modified 2105 ** METHOD: sqlite3 2106 ** 2107 ** ^This function returns the number of rows modified, inserted or 2108 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2109 ** statement on the database connection specified by the only parameter. 2110 ** ^Executing any other type of SQL statement does not modify the value 2111 ** returned by this function. 2112 ** 2113 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2114 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2115 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2116 ** 2117 ** Changes to a view that are intercepted by 2118 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2119 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2120 ** DELETE statement run on a view is always zero. Only changes made to real 2121 ** tables are counted. 2122 ** 2123 ** Things are more complicated if the sqlite3_changes() function is 2124 ** executed while a trigger program is running. This may happen if the 2125 ** program uses the [changes() SQL function], or if some other callback 2126 ** function invokes sqlite3_changes() directly. Essentially: 2127 ** 2128 ** <ul> 2129 ** <li> ^(Before entering a trigger program the value returned by 2130 ** sqlite3_changes() function is saved. After the trigger program 2131 ** has finished, the original value is restored.)^ 2132 ** 2133 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2134 ** statement sets the value returned by sqlite3_changes() 2135 ** upon completion as normal. Of course, this value will not include 2136 ** any changes performed by sub-triggers, as the sqlite3_changes() 2137 ** value will be saved and restored after each sub-trigger has run.)^ 2138 ** </ul> 2139 ** 2140 ** ^This means that if the changes() SQL function (or similar) is used 2141 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2142 ** returns the value as set when the calling statement began executing. 2143 ** ^If it is used by the second or subsequent such statement within a trigger 2144 ** program, the value returned reflects the number of rows modified by the 2145 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2146 ** 2147 ** See also the [sqlite3_total_changes()] interface, the 2148 ** [count_changes pragma], and the [changes() SQL function]. 2149 ** 2150 ** If a separate thread makes changes on the same database connection 2151 ** while [sqlite3_changes()] is running then the value returned 2152 ** is unpredictable and not meaningful. 2153 */ 2154 SQLITE_API int sqlite3_changes(sqlite3*); 2155 2156 /* 2157 ** CAPI3REF: Total Number Of Rows Modified 2158 ** METHOD: sqlite3 2159 ** 2160 ** ^This function returns the total number of rows inserted, modified or 2161 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2162 ** since the database connection was opened, including those executed as 2163 ** part of trigger programs. ^Executing any other type of SQL statement 2164 ** does not affect the value returned by sqlite3_total_changes(). 2165 ** 2166 ** ^Changes made as part of [foreign key actions] are included in the 2167 ** count, but those made as part of REPLACE constraint resolution are 2168 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2169 ** are not counted. 2170 ** 2171 ** See also the [sqlite3_changes()] interface, the 2172 ** [count_changes pragma], and the [total_changes() SQL function]. 2173 ** 2174 ** If a separate thread makes changes on the same database connection 2175 ** while [sqlite3_total_changes()] is running then the value 2176 ** returned is unpredictable and not meaningful. 2177 */ 2178 SQLITE_API int sqlite3_total_changes(sqlite3*); 2179 2180 /* 2181 ** CAPI3REF: Interrupt A Long-Running Query 2182 ** METHOD: sqlite3 2183 ** 2184 ** ^This function causes any pending database operation to abort and 2185 ** return at its earliest opportunity. This routine is typically 2186 ** called in response to a user action such as pressing "Cancel" 2187 ** or Ctrl-C where the user wants a long query operation to halt 2188 ** immediately. 2189 ** 2190 ** ^It is safe to call this routine from a thread different from the 2191 ** thread that is currently running the database operation. But it 2192 ** is not safe to call this routine with a [database connection] that 2193 ** is closed or might close before sqlite3_interrupt() returns. 2194 ** 2195 ** ^If an SQL operation is very nearly finished at the time when 2196 ** sqlite3_interrupt() is called, then it might not have an opportunity 2197 ** to be interrupted and might continue to completion. 2198 ** 2199 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2200 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2201 ** that is inside an explicit transaction, then the entire transaction 2202 ** will be rolled back automatically. 2203 ** 2204 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2205 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2206 ** that are started after the sqlite3_interrupt() call and before the 2207 ** running statements reaches zero are interrupted as if they had been 2208 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2209 ** that are started after the running statement count reaches zero are 2210 ** not effected by the sqlite3_interrupt(). 2211 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2212 ** SQL statements is a no-op and has no effect on SQL statements 2213 ** that are started after the sqlite3_interrupt() call returns. 2214 ** 2215 ** If the database connection closes while [sqlite3_interrupt()] 2216 ** is running then bad things will likely happen. 2217 */ 2218 SQLITE_API void sqlite3_interrupt(sqlite3*); 2219 2220 /* 2221 ** CAPI3REF: Determine If An SQL Statement Is Complete 2222 ** 2223 ** These routines are useful during command-line input to determine if the 2224 ** currently entered text seems to form a complete SQL statement or 2225 ** if additional input is needed before sending the text into 2226 ** SQLite for parsing. ^These routines return 1 if the input string 2227 ** appears to be a complete SQL statement. ^A statement is judged to be 2228 ** complete if it ends with a semicolon token and is not a prefix of a 2229 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2230 ** string literals or quoted identifier names or comments are not 2231 ** independent tokens (they are part of the token in which they are 2232 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2233 ** and comments that follow the final semicolon are ignored. 2234 ** 2235 ** ^These routines return 0 if the statement is incomplete. ^If a 2236 ** memory allocation fails, then SQLITE_NOMEM is returned. 2237 ** 2238 ** ^These routines do not parse the SQL statements thus 2239 ** will not detect syntactically incorrect SQL. 2240 ** 2241 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2242 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2243 ** automatically by sqlite3_complete16(). If that initialization fails, 2244 ** then the return value from sqlite3_complete16() will be non-zero 2245 ** regardless of whether or not the input SQL is complete.)^ 2246 ** 2247 ** The input to [sqlite3_complete()] must be a zero-terminated 2248 ** UTF-8 string. 2249 ** 2250 ** The input to [sqlite3_complete16()] must be a zero-terminated 2251 ** UTF-16 string in native byte order. 2252 */ 2253 SQLITE_API int sqlite3_complete(const char *sql); 2254 SQLITE_API int sqlite3_complete16(const void *sql); 2255 2256 /* 2257 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2258 ** KEYWORDS: {busy-handler callback} {busy handler} 2259 ** METHOD: sqlite3 2260 ** 2261 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2262 ** that might be invoked with argument P whenever 2263 ** an attempt is made to access a database table associated with 2264 ** [database connection] D when another thread 2265 ** or process has the table locked. 2266 ** The sqlite3_busy_handler() interface is used to implement 2267 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2268 ** 2269 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2270 ** is returned immediately upon encountering the lock. ^If the busy callback 2271 ** is not NULL, then the callback might be invoked with two arguments. 2272 ** 2273 ** ^The first argument to the busy handler is a copy of the void* pointer which 2274 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2275 ** the busy handler callback is the number of times that the busy handler has 2276 ** been invoked previously for the same locking event. ^If the 2277 ** busy callback returns 0, then no additional attempts are made to 2278 ** access the database and [SQLITE_BUSY] is returned 2279 ** to the application. 2280 ** ^If the callback returns non-zero, then another attempt 2281 ** is made to access the database and the cycle repeats. 2282 ** 2283 ** The presence of a busy handler does not guarantee that it will be invoked 2284 ** when there is lock contention. ^If SQLite determines that invoking the busy 2285 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2286 ** to the application instead of invoking the 2287 ** busy handler. 2288 ** Consider a scenario where one process is holding a read lock that 2289 ** it is trying to promote to a reserved lock and 2290 ** a second process is holding a reserved lock that it is trying 2291 ** to promote to an exclusive lock. The first process cannot proceed 2292 ** because it is blocked by the second and the second process cannot 2293 ** proceed because it is blocked by the first. If both processes 2294 ** invoke the busy handlers, neither will make any progress. Therefore, 2295 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2296 ** will induce the first process to release its read lock and allow 2297 ** the second process to proceed. 2298 ** 2299 ** ^The default busy callback is NULL. 2300 ** 2301 ** ^(There can only be a single busy handler defined for each 2302 ** [database connection]. Setting a new busy handler clears any 2303 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2304 ** or evaluating [PRAGMA busy_timeout=N] will change the 2305 ** busy handler and thus clear any previously set busy handler. 2306 ** 2307 ** The busy callback should not take any actions which modify the 2308 ** database connection that invoked the busy handler. In other words, 2309 ** the busy handler is not reentrant. Any such actions 2310 ** result in undefined behavior. 2311 ** 2312 ** A busy handler must not close the database connection 2313 ** or [prepared statement] that invoked the busy handler. 2314 */ 2315 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2316 2317 /* 2318 ** CAPI3REF: Set A Busy Timeout 2319 ** METHOD: sqlite3 2320 ** 2321 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2322 ** for a specified amount of time when a table is locked. ^The handler 2323 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2324 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2325 ** the handler returns 0 which causes [sqlite3_step()] to return 2326 ** [SQLITE_BUSY]. 2327 ** 2328 ** ^Calling this routine with an argument less than or equal to zero 2329 ** turns off all busy handlers. 2330 ** 2331 ** ^(There can only be a single busy handler for a particular 2332 ** [database connection] at any given moment. If another busy handler 2333 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2334 ** this routine, that other busy handler is cleared.)^ 2335 ** 2336 ** See also: [PRAGMA busy_timeout] 2337 */ 2338 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2339 2340 /* 2341 ** CAPI3REF: Convenience Routines For Running Queries 2342 ** METHOD: sqlite3 2343 ** 2344 ** This is a legacy interface that is preserved for backwards compatibility. 2345 ** Use of this interface is not recommended. 2346 ** 2347 ** Definition: A <b>result table</b> is memory data structure created by the 2348 ** [sqlite3_get_table()] interface. A result table records the 2349 ** complete query results from one or more queries. 2350 ** 2351 ** The table conceptually has a number of rows and columns. But 2352 ** these numbers are not part of the result table itself. These 2353 ** numbers are obtained separately. Let N be the number of rows 2354 ** and M be the number of columns. 2355 ** 2356 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2357 ** There are (N+1)*M elements in the array. The first M pointers point 2358 ** to zero-terminated strings that contain the names of the columns. 2359 ** The remaining entries all point to query results. NULL values result 2360 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2361 ** string representation as returned by [sqlite3_column_text()]. 2362 ** 2363 ** A result table might consist of one or more memory allocations. 2364 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2365 ** A result table should be deallocated using [sqlite3_free_table()]. 2366 ** 2367 ** ^(As an example of the result table format, suppose a query result 2368 ** is as follows: 2369 ** 2370 ** <blockquote><pre> 2371 ** Name | Age 2372 ** ----------------------- 2373 ** Alice | 43 2374 ** Bob | 28 2375 ** Cindy | 21 2376 ** </pre></blockquote> 2377 ** 2378 ** There are two column (M==2) and three rows (N==3). Thus the 2379 ** result table has 8 entries. Suppose the result table is stored 2380 ** in an array names azResult. Then azResult holds this content: 2381 ** 2382 ** <blockquote><pre> 2383 ** azResult[0] = "Name"; 2384 ** azResult[1] = "Age"; 2385 ** azResult[2] = "Alice"; 2386 ** azResult[3] = "43"; 2387 ** azResult[4] = "Bob"; 2388 ** azResult[5] = "28"; 2389 ** azResult[6] = "Cindy"; 2390 ** azResult[7] = "21"; 2391 ** </pre></blockquote>)^ 2392 ** 2393 ** ^The sqlite3_get_table() function evaluates one or more 2394 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2395 ** string of its 2nd parameter and returns a result table to the 2396 ** pointer given in its 3rd parameter. 2397 ** 2398 ** After the application has finished with the result from sqlite3_get_table(), 2399 ** it must pass the result table pointer to sqlite3_free_table() in order to 2400 ** release the memory that was malloced. Because of the way the 2401 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2402 ** function must not try to call [sqlite3_free()] directly. Only 2403 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2404 ** 2405 ** The sqlite3_get_table() interface is implemented as a wrapper around 2406 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2407 ** to any internal data structures of SQLite. It uses only the public 2408 ** interface defined here. As a consequence, errors that occur in the 2409 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2410 ** reflected in subsequent calls to [sqlite3_errcode()] or 2411 ** [sqlite3_errmsg()]. 2412 */ 2413 SQLITE_API int sqlite3_get_table( 2414 sqlite3 *db, /* An open database */ 2415 const char *zSql, /* SQL to be evaluated */ 2416 char ***pazResult, /* Results of the query */ 2417 int *pnRow, /* Number of result rows written here */ 2418 int *pnColumn, /* Number of result columns written here */ 2419 char **pzErrmsg /* Error msg written here */ 2420 ); 2421 SQLITE_API void sqlite3_free_table(char **result); 2422 2423 /* 2424 ** CAPI3REF: Formatted String Printing Functions 2425 ** 2426 ** These routines are work-alikes of the "printf()" family of functions 2427 ** from the standard C library. 2428 ** These routines understand most of the common K&R formatting options, 2429 ** plus some additional non-standard formats, detailed below. 2430 ** Note that some of the more obscure formatting options from recent 2431 ** C-library standards are omitted from this implementation. 2432 ** 2433 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2434 ** results into memory obtained from [sqlite3_malloc()]. 2435 ** The strings returned by these two routines should be 2436 ** released by [sqlite3_free()]. ^Both routines return a 2437 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2438 ** memory to hold the resulting string. 2439 ** 2440 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2441 ** the standard C library. The result is written into the 2442 ** buffer supplied as the second parameter whose size is given by 2443 ** the first parameter. Note that the order of the 2444 ** first two parameters is reversed from snprintf().)^ This is an 2445 ** historical accident that cannot be fixed without breaking 2446 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2447 ** returns a pointer to its buffer instead of the number of 2448 ** characters actually written into the buffer.)^ We admit that 2449 ** the number of characters written would be a more useful return 2450 ** value but we cannot change the implementation of sqlite3_snprintf() 2451 ** now without breaking compatibility. 2452 ** 2453 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2454 ** guarantees that the buffer is always zero-terminated. ^The first 2455 ** parameter "n" is the total size of the buffer, including space for 2456 ** the zero terminator. So the longest string that can be completely 2457 ** written will be n-1 characters. 2458 ** 2459 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2460 ** 2461 ** These routines all implement some additional formatting 2462 ** options that are useful for constructing SQL statements. 2463 ** All of the usual printf() formatting options apply. In addition, there 2464 ** is are "%q", "%Q", "%w" and "%z" options. 2465 ** 2466 ** ^(The %q option works like %s in that it substitutes a nul-terminated 2467 ** string from the argument list. But %q also doubles every '\'' character. 2468 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2469 ** character it escapes that character and allows it to be inserted into 2470 ** the string. 2471 ** 2472 ** For example, assume the string variable zText contains text as follows: 2473 ** 2474 ** <blockquote><pre> 2475 ** char *zText = "It's a happy day!"; 2476 ** </pre></blockquote> 2477 ** 2478 ** One can use this text in an SQL statement as follows: 2479 ** 2480 ** <blockquote><pre> 2481 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2482 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2483 ** sqlite3_free(zSQL); 2484 ** </pre></blockquote> 2485 ** 2486 ** Because the %q format string is used, the '\'' character in zText 2487 ** is escaped and the SQL generated is as follows: 2488 ** 2489 ** <blockquote><pre> 2490 ** INSERT INTO table1 VALUES('It''s a happy day!') 2491 ** </pre></blockquote> 2492 ** 2493 ** This is correct. Had we used %s instead of %q, the generated SQL 2494 ** would have looked like this: 2495 ** 2496 ** <blockquote><pre> 2497 ** INSERT INTO table1 VALUES('It's a happy day!'); 2498 ** </pre></blockquote> 2499 ** 2500 ** This second example is an SQL syntax error. As a general rule you should 2501 ** always use %q instead of %s when inserting text into a string literal. 2502 ** 2503 ** ^(The %Q option works like %q except it also adds single quotes around 2504 ** the outside of the total string. Additionally, if the parameter in the 2505 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2506 ** single quotes).)^ So, for example, one could say: 2507 ** 2508 ** <blockquote><pre> 2509 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2510 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2511 ** sqlite3_free(zSQL); 2512 ** </pre></blockquote> 2513 ** 2514 ** The code above will render a correct SQL statement in the zSQL 2515 ** variable even if the zText variable is a NULL pointer. 2516 ** 2517 ** ^(The "%w" formatting option is like "%q" except that it expects to 2518 ** be contained within double-quotes instead of single quotes, and it 2519 ** escapes the double-quote character instead of the single-quote 2520 ** character.)^ The "%w" formatting option is intended for safely inserting 2521 ** table and column names into a constructed SQL statement. 2522 ** 2523 ** ^(The "%z" formatting option works like "%s" but with the 2524 ** addition that after the string has been read and copied into 2525 ** the result, [sqlite3_free()] is called on the input string.)^ 2526 */ 2527 SQLITE_API char *sqlite3_mprintf(const char*,...); 2528 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2529 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2530 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2531 2532 /* 2533 ** CAPI3REF: Memory Allocation Subsystem 2534 ** 2535 ** The SQLite core uses these three routines for all of its own 2536 ** internal memory allocation needs. "Core" in the previous sentence 2537 ** does not include operating-system specific VFS implementation. The 2538 ** Windows VFS uses native malloc() and free() for some operations. 2539 ** 2540 ** ^The sqlite3_malloc() routine returns a pointer to a block 2541 ** of memory at least N bytes in length, where N is the parameter. 2542 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2543 ** memory, it returns a NULL pointer. ^If the parameter N to 2544 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2545 ** a NULL pointer. 2546 ** 2547 ** ^The sqlite3_malloc64(N) routine works just like 2548 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2549 ** of a signed 32-bit integer. 2550 ** 2551 ** ^Calling sqlite3_free() with a pointer previously returned 2552 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2553 ** that it might be reused. ^The sqlite3_free() routine is 2554 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2555 ** to sqlite3_free() is harmless. After being freed, memory 2556 ** should neither be read nor written. Even reading previously freed 2557 ** memory might result in a segmentation fault or other severe error. 2558 ** Memory corruption, a segmentation fault, or other severe error 2559 ** might result if sqlite3_free() is called with a non-NULL pointer that 2560 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2561 ** 2562 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2563 ** prior memory allocation X to be at least N bytes. 2564 ** ^If the X parameter to sqlite3_realloc(X,N) 2565 ** is a NULL pointer then its behavior is identical to calling 2566 ** sqlite3_malloc(N). 2567 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2568 ** negative then the behavior is exactly the same as calling 2569 ** sqlite3_free(X). 2570 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2571 ** of at least N bytes in size or NULL if insufficient memory is available. 2572 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2573 ** of the prior allocation are copied into the beginning of buffer returned 2574 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2575 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2576 ** prior allocation is not freed. 2577 ** 2578 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2579 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2580 ** of a 32-bit signed integer. 2581 ** 2582 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2583 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2584 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2585 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2586 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2587 ** sqlite3_msize(X) returns zero. If X points to something that is not 2588 ** the beginning of memory allocation, or if it points to a formerly 2589 ** valid memory allocation that has now been freed, then the behavior 2590 ** of sqlite3_msize(X) is undefined and possibly harmful. 2591 ** 2592 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2593 ** sqlite3_malloc64(), and sqlite3_realloc64() 2594 ** is always aligned to at least an 8 byte boundary, or to a 2595 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2596 ** option is used. 2597 ** 2598 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2599 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2600 ** implementation of these routines to be omitted. That capability 2601 ** is no longer provided. Only built-in memory allocators can be used. 2602 ** 2603 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2604 ** the system malloc() and free() directly when converting 2605 ** filenames between the UTF-8 encoding used by SQLite 2606 ** and whatever filename encoding is used by the particular Windows 2607 ** installation. Memory allocation errors were detected, but 2608 ** they were reported back as [SQLITE_CANTOPEN] or 2609 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2610 ** 2611 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2612 ** must be either NULL or else pointers obtained from a prior 2613 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2614 ** not yet been released. 2615 ** 2616 ** The application must not read or write any part of 2617 ** a block of memory after it has been released using 2618 ** [sqlite3_free()] or [sqlite3_realloc()]. 2619 */ 2620 SQLITE_API void *sqlite3_malloc(int); 2621 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2622 SQLITE_API void *sqlite3_realloc(void*, int); 2623 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2624 SQLITE_API void sqlite3_free(void*); 2625 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2626 2627 /* 2628 ** CAPI3REF: Memory Allocator Statistics 2629 ** 2630 ** SQLite provides these two interfaces for reporting on the status 2631 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2632 ** routines, which form the built-in memory allocation subsystem. 2633 ** 2634 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2635 ** of memory currently outstanding (malloced but not freed). 2636 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2637 ** value of [sqlite3_memory_used()] since the high-water mark 2638 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2639 ** [sqlite3_memory_highwater()] include any overhead 2640 ** added by SQLite in its implementation of [sqlite3_malloc()], 2641 ** but not overhead added by the any underlying system library 2642 ** routines that [sqlite3_malloc()] may call. 2643 ** 2644 ** ^The memory high-water mark is reset to the current value of 2645 ** [sqlite3_memory_used()] if and only if the parameter to 2646 ** [sqlite3_memory_highwater()] is true. ^The value returned 2647 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2648 ** prior to the reset. 2649 */ 2650 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2651 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2652 2653 /* 2654 ** CAPI3REF: Pseudo-Random Number Generator 2655 ** 2656 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2657 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2658 ** already uses the largest possible [ROWID]. The PRNG is also used for 2659 ** the build-in random() and randomblob() SQL functions. This interface allows 2660 ** applications to access the same PRNG for other purposes. 2661 ** 2662 ** ^A call to this routine stores N bytes of randomness into buffer P. 2663 ** ^The P parameter can be a NULL pointer. 2664 ** 2665 ** ^If this routine has not been previously called or if the previous 2666 ** call had N less than one or a NULL pointer for P, then the PRNG is 2667 ** seeded using randomness obtained from the xRandomness method of 2668 ** the default [sqlite3_vfs] object. 2669 ** ^If the previous call to this routine had an N of 1 or more and a 2670 ** non-NULL P then the pseudo-randomness is generated 2671 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2672 ** method. 2673 */ 2674 SQLITE_API void sqlite3_randomness(int N, void *P); 2675 2676 /* 2677 ** CAPI3REF: Compile-Time Authorization Callbacks 2678 ** METHOD: sqlite3 2679 ** 2680 ** ^This routine registers an authorizer callback with a particular 2681 ** [database connection], supplied in the first argument. 2682 ** ^The authorizer callback is invoked as SQL statements are being compiled 2683 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2684 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2685 ** points during the compilation process, as logic is being created 2686 ** to perform various actions, the authorizer callback is invoked to 2687 ** see if those actions are allowed. ^The authorizer callback should 2688 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2689 ** specific action but allow the SQL statement to continue to be 2690 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2691 ** rejected with an error. ^If the authorizer callback returns 2692 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2693 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2694 ** the authorizer will fail with an error message. 2695 ** 2696 ** When the callback returns [SQLITE_OK], that means the operation 2697 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2698 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2699 ** authorizer will fail with an error message explaining that 2700 ** access is denied. 2701 ** 2702 ** ^The first parameter to the authorizer callback is a copy of the third 2703 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2704 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2705 ** the particular action to be authorized. ^The third through sixth parameters 2706 ** to the callback are zero-terminated strings that contain additional 2707 ** details about the action to be authorized. 2708 ** 2709 ** ^If the action code is [SQLITE_READ] 2710 ** and the callback returns [SQLITE_IGNORE] then the 2711 ** [prepared statement] statement is constructed to substitute 2712 ** a NULL value in place of the table column that would have 2713 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2714 ** return can be used to deny an untrusted user access to individual 2715 ** columns of a table. 2716 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2717 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2718 ** [truncate optimization] is disabled and all rows are deleted individually. 2719 ** 2720 ** An authorizer is used when [sqlite3_prepare | preparing] 2721 ** SQL statements from an untrusted source, to ensure that the SQL statements 2722 ** do not try to access data they are not allowed to see, or that they do not 2723 ** try to execute malicious statements that damage the database. For 2724 ** example, an application may allow a user to enter arbitrary 2725 ** SQL queries for evaluation by a database. But the application does 2726 ** not want the user to be able to make arbitrary changes to the 2727 ** database. An authorizer could then be put in place while the 2728 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2729 ** disallows everything except [SELECT] statements. 2730 ** 2731 ** Applications that need to process SQL from untrusted sources 2732 ** might also consider lowering resource limits using [sqlite3_limit()] 2733 ** and limiting database size using the [max_page_count] [PRAGMA] 2734 ** in addition to using an authorizer. 2735 ** 2736 ** ^(Only a single authorizer can be in place on a database connection 2737 ** at a time. Each call to sqlite3_set_authorizer overrides the 2738 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2739 ** The authorizer is disabled by default. 2740 ** 2741 ** The authorizer callback must not do anything that will modify 2742 ** the database connection that invoked the authorizer callback. 2743 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2744 ** database connections for the meaning of "modify" in this paragraph. 2745 ** 2746 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2747 ** statement might be re-prepared during [sqlite3_step()] due to a 2748 ** schema change. Hence, the application should ensure that the 2749 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2750 ** 2751 ** ^Note that the authorizer callback is invoked only during 2752 ** [sqlite3_prepare()] or its variants. Authorization is not 2753 ** performed during statement evaluation in [sqlite3_step()], unless 2754 ** as stated in the previous paragraph, sqlite3_step() invokes 2755 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2756 */ 2757 SQLITE_API int sqlite3_set_authorizer( 2758 sqlite3*, 2759 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2760 void *pUserData 2761 ); 2762 2763 /* 2764 ** CAPI3REF: Authorizer Return Codes 2765 ** 2766 ** The [sqlite3_set_authorizer | authorizer callback function] must 2767 ** return either [SQLITE_OK] or one of these two constants in order 2768 ** to signal SQLite whether or not the action is permitted. See the 2769 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2770 ** information. 2771 ** 2772 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2773 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2774 */ 2775 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2776 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2777 2778 /* 2779 ** CAPI3REF: Authorizer Action Codes 2780 ** 2781 ** The [sqlite3_set_authorizer()] interface registers a callback function 2782 ** that is invoked to authorize certain SQL statement actions. The 2783 ** second parameter to the callback is an integer code that specifies 2784 ** what action is being authorized. These are the integer action codes that 2785 ** the authorizer callback may be passed. 2786 ** 2787 ** These action code values signify what kind of operation is to be 2788 ** authorized. The 3rd and 4th parameters to the authorization 2789 ** callback function will be parameters or NULL depending on which of these 2790 ** codes is used as the second parameter. ^(The 5th parameter to the 2791 ** authorizer callback is the name of the database ("main", "temp", 2792 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2793 ** is the name of the inner-most trigger or view that is responsible for 2794 ** the access attempt or NULL if this access attempt is directly from 2795 ** top-level SQL code. 2796 */ 2797 /******************************************* 3rd ************ 4th ***********/ 2798 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2799 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2800 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2801 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2802 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2803 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2804 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2805 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2806 #define SQLITE_DELETE 9 /* Table Name NULL */ 2807 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2808 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2809 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2810 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2811 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2812 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2813 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2814 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2815 #define SQLITE_INSERT 18 /* Table Name NULL */ 2816 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2817 #define SQLITE_READ 20 /* Table Name Column Name */ 2818 #define SQLITE_SELECT 21 /* NULL NULL */ 2819 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2820 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2821 #define SQLITE_ATTACH 24 /* Filename NULL */ 2822 #define SQLITE_DETACH 25 /* Database Name NULL */ 2823 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2824 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2825 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2826 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2827 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2828 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2829 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2830 #define SQLITE_COPY 0 /* No longer used */ 2831 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2832 2833 /* 2834 ** CAPI3REF: Tracing And Profiling Functions 2835 ** METHOD: sqlite3 2836 ** 2837 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2838 ** instead of the routines described here. 2839 ** 2840 ** These routines register callback functions that can be used for 2841 ** tracing and profiling the execution of SQL statements. 2842 ** 2843 ** ^The callback function registered by sqlite3_trace() is invoked at 2844 ** various times when an SQL statement is being run by [sqlite3_step()]. 2845 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2846 ** SQL statement text as the statement first begins executing. 2847 ** ^(Additional sqlite3_trace() callbacks might occur 2848 ** as each triggered subprogram is entered. The callbacks for triggers 2849 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2850 ** 2851 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2852 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2853 ** 2854 ** ^The callback function registered by sqlite3_profile() is invoked 2855 ** as each SQL statement finishes. ^The profile callback contains 2856 ** the original statement text and an estimate of wall-clock time 2857 ** of how long that statement took to run. ^The profile callback 2858 ** time is in units of nanoseconds, however the current implementation 2859 ** is only capable of millisecond resolution so the six least significant 2860 ** digits in the time are meaningless. Future versions of SQLite 2861 ** might provide greater resolution on the profiler callback. The 2862 ** sqlite3_profile() function is considered experimental and is 2863 ** subject to change in future versions of SQLite. 2864 */ 2865 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2866 void(*xTrace)(void*,const char*), void*); 2867 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2868 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2869 2870 /* 2871 ** CAPI3REF: SQL Trace Event Codes 2872 ** KEYWORDS: SQLITE_TRACE 2873 ** 2874 ** These constants identify classes of events that can be monitored 2875 ** using the [sqlite3_trace_v2()] tracing logic. The third argument 2876 ** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2877 ** the following constants. ^The first argument to the trace callback 2878 ** is one of the following constants. 2879 ** 2880 ** New tracing constants may be added in future releases. 2881 ** 2882 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 2883 ** ^The T argument is one of the integer type codes above. 2884 ** ^The C argument is a copy of the context pointer passed in as the 2885 ** fourth argument to [sqlite3_trace_v2()]. 2886 ** The P and X arguments are pointers whose meanings depend on T. 2887 ** 2888 ** <dl> 2889 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2890 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2891 ** first begins running and possibly at other times during the 2892 ** execution of the prepared statement, such as at the start of each 2893 ** trigger subprogram. ^The P argument is a pointer to the 2894 ** [prepared statement]. ^The X argument is a pointer to a string which 2895 ** is the unexpanded SQL text of the prepared statement or an SQL comment 2896 ** that indicates the invocation of a trigger. ^The callback can compute 2897 ** the same text that would have been returned by the legacy [sqlite3_trace()] 2898 ** interface by using the X argument when X begins with "--" and invoking 2899 ** [sqlite3_expanded_sql(P)] otherwise. 2900 ** 2901 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2902 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2903 ** information as is provided by the [sqlite3_profile()] callback. 2904 ** ^The P argument is a pointer to the [prepared statement] and the 2905 ** X argument points to a 64-bit integer which is the estimated of 2906 ** the number of nanosecond that the prepared statement took to run. 2907 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2908 ** 2909 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2910 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2911 ** statement generates a single row of result. 2912 ** ^The P argument is a pointer to the [prepared statement] and the 2913 ** X argument is unused. 2914 ** 2915 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2916 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2917 ** connection closes. 2918 ** ^The P argument is a pointer to the [database connection] object 2919 ** and the X argument is unused. 2920 ** </dl> 2921 */ 2922 #define SQLITE_TRACE_STMT 0x01 2923 #define SQLITE_TRACE_PROFILE 0x02 2924 #define SQLITE_TRACE_ROW 0x04 2925 #define SQLITE_TRACE_CLOSE 0x08 2926 2927 /* 2928 ** CAPI3REF: SQL Trace Hook 2929 ** METHOD: sqlite3 2930 ** 2931 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2932 ** function X against [database connection] D, using property mask M 2933 ** and context pointer P. ^If the X callback is 2934 ** NULL or if the M mask is zero, then tracing is disabled. The 2935 ** M argument should be the bitwise OR-ed combination of 2936 ** zero or more [SQLITE_TRACE] constants. 2937 ** 2938 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2939 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2940 ** 2941 ** ^The X callback is invoked whenever any of the events identified by 2942 ** mask M occur. ^The integer return value from the callback is currently 2943 ** ignored, though this may change in future releases. Callback 2944 ** implementations should return zero to ensure future compatibility. 2945 ** 2946 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2947 ** ^The T argument is one of the [SQLITE_TRACE] 2948 ** constants to indicate why the callback was invoked. 2949 ** ^The C argument is a copy of the context pointer. 2950 ** The P and X arguments are pointers whose meanings depend on T. 2951 ** 2952 ** The sqlite3_trace_v2() interface is intended to replace the legacy 2953 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 2954 ** are deprecated. 2955 */ 2956 SQLITE_API int sqlite3_trace_v2( 2957 sqlite3*, 2958 unsigned uMask, 2959 int(*xCallback)(unsigned,void*,void*,void*), 2960 void *pCtx 2961 ); 2962 2963 /* 2964 ** CAPI3REF: Query Progress Callbacks 2965 ** METHOD: sqlite3 2966 ** 2967 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2968 ** function X to be invoked periodically during long running calls to 2969 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2970 ** database connection D. An example use for this 2971 ** interface is to keep a GUI updated during a large query. 2972 ** 2973 ** ^The parameter P is passed through as the only parameter to the 2974 ** callback function X. ^The parameter N is the approximate number of 2975 ** [virtual machine instructions] that are evaluated between successive 2976 ** invocations of the callback X. ^If N is less than one then the progress 2977 ** handler is disabled. 2978 ** 2979 ** ^Only a single progress handler may be defined at one time per 2980 ** [database connection]; setting a new progress handler cancels the 2981 ** old one. ^Setting parameter X to NULL disables the progress handler. 2982 ** ^The progress handler is also disabled by setting N to a value less 2983 ** than 1. 2984 ** 2985 ** ^If the progress callback returns non-zero, the operation is 2986 ** interrupted. This feature can be used to implement a 2987 ** "Cancel" button on a GUI progress dialog box. 2988 ** 2989 ** The progress handler callback must not do anything that will modify 2990 ** the database connection that invoked the progress handler. 2991 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2992 ** database connections for the meaning of "modify" in this paragraph. 2993 ** 2994 */ 2995 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2996 2997 /* 2998 ** CAPI3REF: Opening A New Database Connection 2999 ** CONSTRUCTOR: sqlite3 3000 ** 3001 ** ^These routines open an SQLite database file as specified by the 3002 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3003 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3004 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3005 ** returned in *ppDb, even if an error occurs. The only exception is that 3006 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3007 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3008 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3009 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3010 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3011 ** an English language description of the error following a failure of any 3012 ** of the sqlite3_open() routines. 3013 ** 3014 ** ^The default encoding will be UTF-8 for databases created using 3015 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3016 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3017 ** 3018 ** Whether or not an error occurs when it is opened, resources 3019 ** associated with the [database connection] handle should be released by 3020 ** passing it to [sqlite3_close()] when it is no longer required. 3021 ** 3022 ** The sqlite3_open_v2() interface works like sqlite3_open() 3023 ** except that it accepts two additional parameters for additional control 3024 ** over the new database connection. ^(The flags parameter to 3025 ** sqlite3_open_v2() can take one of 3026 ** the following three values, optionally combined with the 3027 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3028 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3029 ** 3030 ** <dl> 3031 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3032 ** <dd>The database is opened in read-only mode. If the database does not 3033 ** already exist, an error is returned.</dd>)^ 3034 ** 3035 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3036 ** <dd>The database is opened for reading and writing if possible, or reading 3037 ** only if the file is write protected by the operating system. In either 3038 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3039 ** 3040 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3041 ** <dd>The database is opened for reading and writing, and is created if 3042 ** it does not already exist. This is the behavior that is always used for 3043 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3044 ** </dl> 3045 ** 3046 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3047 ** combinations shown above optionally combined with other 3048 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3049 ** then the behavior is undefined. 3050 ** 3051 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3052 ** opens in the multi-thread [threading mode] as long as the single-thread 3053 ** mode has not been set at compile-time or start-time. ^If the 3054 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3055 ** in the serialized [threading mode] unless single-thread was 3056 ** previously selected at compile-time or start-time. 3057 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3058 ** eligible to use [shared cache mode], regardless of whether or not shared 3059 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3060 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3061 ** participate in [shared cache mode] even if it is enabled. 3062 ** 3063 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3064 ** [sqlite3_vfs] object that defines the operating system interface that 3065 ** the new database connection should use. ^If the fourth parameter is 3066 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3067 ** 3068 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3069 ** is created for the connection. ^This in-memory database will vanish when 3070 ** the database connection is closed. Future versions of SQLite might 3071 ** make use of additional special filenames that begin with the ":" character. 3072 ** It is recommended that when a database filename actually does begin with 3073 ** a ":" character you should prefix the filename with a pathname such as 3074 ** "./" to avoid ambiguity. 3075 ** 3076 ** ^If the filename is an empty string, then a private, temporary 3077 ** on-disk database will be created. ^This private database will be 3078 ** automatically deleted as soon as the database connection is closed. 3079 ** 3080 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3081 ** 3082 ** ^If [URI filename] interpretation is enabled, and the filename argument 3083 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3084 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3085 ** set in the fourth argument to sqlite3_open_v2(), or if it has 3086 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3087 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3088 ** As of SQLite version 3.7.7, URI filename interpretation is turned off 3089 ** by default, but future releases of SQLite might enable URI filename 3090 ** interpretation by default. See "[URI filenames]" for additional 3091 ** information. 3092 ** 3093 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3094 ** authority, then it must be either an empty string or the string 3095 ** "localhost". ^If the authority is not an empty string or "localhost", an 3096 ** error is returned to the caller. ^The fragment component of a URI, if 3097 ** present, is ignored. 3098 ** 3099 ** ^SQLite uses the path component of the URI as the name of the disk file 3100 ** which contains the database. ^If the path begins with a '/' character, 3101 ** then it is interpreted as an absolute path. ^If the path does not begin 3102 ** with a '/' (meaning that the authority section is omitted from the URI) 3103 ** then the path is interpreted as a relative path. 3104 ** ^(On windows, the first component of an absolute path 3105 ** is a drive specification (e.g. "C:").)^ 3106 ** 3107 ** [[core URI query parameters]] 3108 ** The query component of a URI may contain parameters that are interpreted 3109 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3110 ** SQLite and its built-in [VFSes] interpret the 3111 ** following query parameters: 3112 ** 3113 ** <ul> 3114 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3115 ** a VFS object that provides the operating system interface that should 3116 ** be used to access the database file on disk. ^If this option is set to 3117 ** an empty string the default VFS object is used. ^Specifying an unknown 3118 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3119 ** present, then the VFS specified by the option takes precedence over 3120 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3121 ** 3122 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3123 ** "rwc", or "memory". Attempting to set it to any other value is 3124 ** an error)^. 3125 ** ^If "ro" is specified, then the database is opened for read-only 3126 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3127 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3128 ** "rw", then the database is opened for read-write (but not create) 3129 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3130 ** been set. ^Value "rwc" is equivalent to setting both 3131 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3132 ** set to "memory" then a pure [in-memory database] that never reads 3133 ** or writes from disk is used. ^It is an error to specify a value for 3134 ** the mode parameter that is less restrictive than that specified by 3135 ** the flags passed in the third parameter to sqlite3_open_v2(). 3136 ** 3137 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3138 ** "private". ^Setting it to "shared" is equivalent to setting the 3139 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3140 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3141 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3142 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3143 ** a URI filename, its value overrides any behavior requested by setting 3144 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3145 ** 3146 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3147 ** [powersafe overwrite] property does or does not apply to the 3148 ** storage media on which the database file resides. 3149 ** 3150 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3151 ** which if set disables file locking in rollback journal modes. This 3152 ** is useful for accessing a database on a filesystem that does not 3153 ** support locking. Caution: Database corruption might result if two 3154 ** or more processes write to the same database and any one of those 3155 ** processes uses nolock=1. 3156 ** 3157 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3158 ** parameter that indicates that the database file is stored on 3159 ** read-only media. ^When immutable is set, SQLite assumes that the 3160 ** database file cannot be changed, even by a process with higher 3161 ** privilege, and so the database is opened read-only and all locking 3162 ** and change detection is disabled. Caution: Setting the immutable 3163 ** property on a database file that does in fact change can result 3164 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3165 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3166 ** 3167 ** </ul> 3168 ** 3169 ** ^Specifying an unknown parameter in the query component of a URI is not an 3170 ** error. Future versions of SQLite might understand additional query 3171 ** parameters. See "[query parameters with special meaning to SQLite]" for 3172 ** additional information. 3173 ** 3174 ** [[URI filename examples]] <h3>URI filename examples</h3> 3175 ** 3176 ** <table border="1" align=center cellpadding=5> 3177 ** <tr><th> URI filenames <th> Results 3178 ** <tr><td> file:data.db <td> 3179 ** Open the file "data.db" in the current directory. 3180 ** <tr><td> file:/home/fred/data.db<br> 3181 ** file:///home/fred/data.db <br> 3182 ** file://localhost/home/fred/data.db <br> <td> 3183 ** Open the database file "/home/fred/data.db". 3184 ** <tr><td> file://darkstar/home/fred/data.db <td> 3185 ** An error. "darkstar" is not a recognized authority. 3186 ** <tr><td style="white-space:nowrap"> 3187 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3188 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3189 ** C:. Note that the %20 escaping in this example is not strictly 3190 ** necessary - space characters can be used literally 3191 ** in URI filenames. 3192 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3193 ** Open file "data.db" in the current directory for read-only access. 3194 ** Regardless of whether or not shared-cache mode is enabled by 3195 ** default, use a private cache. 3196 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3197 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3198 ** that uses dot-files in place of posix advisory locking. 3199 ** <tr><td> file:data.db?mode=readonly <td> 3200 ** An error. "readonly" is not a valid option for the "mode" parameter. 3201 ** </table> 3202 ** 3203 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3204 ** query components of a URI. A hexadecimal escape sequence consists of a 3205 ** percent sign - "%" - followed by exactly two hexadecimal digits 3206 ** specifying an octet value. ^Before the path or query components of a 3207 ** URI filename are interpreted, they are encoded using UTF-8 and all 3208 ** hexadecimal escape sequences replaced by a single byte containing the 3209 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3210 ** the results are undefined. 3211 ** 3212 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3213 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3214 ** codepage is currently defined. Filenames containing international 3215 ** characters must be converted to UTF-8 prior to passing them into 3216 ** sqlite3_open() or sqlite3_open_v2(). 3217 ** 3218 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3219 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3220 ** features that require the use of temporary files may fail. 3221 ** 3222 ** See also: [sqlite3_temp_directory] 3223 */ 3224 SQLITE_API int sqlite3_open( 3225 const char *filename, /* Database filename (UTF-8) */ 3226 sqlite3 **ppDb /* OUT: SQLite db handle */ 3227 ); 3228 SQLITE_API int sqlite3_open16( 3229 const void *filename, /* Database filename (UTF-16) */ 3230 sqlite3 **ppDb /* OUT: SQLite db handle */ 3231 ); 3232 SQLITE_API int sqlite3_open_v2( 3233 const char *filename, /* Database filename (UTF-8) */ 3234 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3235 int flags, /* Flags */ 3236 const char *zVfs /* Name of VFS module to use */ 3237 ); 3238 3239 /* 3240 ** CAPI3REF: Obtain Values For URI Parameters 3241 ** 3242 ** These are utility routines, useful to VFS implementations, that check 3243 ** to see if a database file was a URI that contained a specific query 3244 ** parameter, and if so obtains the value of that query parameter. 3245 ** 3246 ** If F is the database filename pointer passed into the xOpen() method of 3247 ** a VFS implementation when the flags parameter to xOpen() has one or 3248 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3249 ** P is the name of the query parameter, then 3250 ** sqlite3_uri_parameter(F,P) returns the value of the P 3251 ** parameter if it exists or a NULL pointer if P does not appear as a 3252 ** query parameter on F. If P is a query parameter of F 3253 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3254 ** a pointer to an empty string. 3255 ** 3256 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3257 ** parameter and returns true (1) or false (0) according to the value 3258 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3259 ** value of query parameter P is one of "yes", "true", or "on" in any 3260 ** case or if the value begins with a non-zero number. The 3261 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3262 ** query parameter P is one of "no", "false", or "off" in any case or 3263 ** if the value begins with a numeric zero. If P is not a query 3264 ** parameter on F or if the value of P is does not match any of the 3265 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3266 ** 3267 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3268 ** 64-bit signed integer and returns that integer, or D if P does not 3269 ** exist. If the value of P is something other than an integer, then 3270 ** zero is returned. 3271 ** 3272 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3273 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3274 ** is not a database file pathname pointer that SQLite passed into the xOpen 3275 ** VFS method, then the behavior of this routine is undefined and probably 3276 ** undesirable. 3277 */ 3278 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3279 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3280 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3281 3282 3283 /* 3284 ** CAPI3REF: Error Codes And Messages 3285 ** METHOD: sqlite3 3286 ** 3287 ** ^If the most recent sqlite3_* API call associated with 3288 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3289 ** returns the numeric [result code] or [extended result code] for that 3290 ** API call. 3291 ** If the most recent API call was successful, 3292 ** then the return value from sqlite3_errcode() is undefined. 3293 ** ^The sqlite3_extended_errcode() 3294 ** interface is the same except that it always returns the 3295 ** [extended result code] even when extended result codes are 3296 ** disabled. 3297 ** 3298 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3299 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3300 ** ^(Memory to hold the error message string is managed internally. 3301 ** The application does not need to worry about freeing the result. 3302 ** However, the error string might be overwritten or deallocated by 3303 ** subsequent calls to other SQLite interface functions.)^ 3304 ** 3305 ** ^The sqlite3_errstr() interface returns the English-language text 3306 ** that describes the [result code], as UTF-8. 3307 ** ^(Memory to hold the error message string is managed internally 3308 ** and must not be freed by the application)^. 3309 ** 3310 ** When the serialized [threading mode] is in use, it might be the 3311 ** case that a second error occurs on a separate thread in between 3312 ** the time of the first error and the call to these interfaces. 3313 ** When that happens, the second error will be reported since these 3314 ** interfaces always report the most recent result. To avoid 3315 ** this, each thread can obtain exclusive use of the [database connection] D 3316 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3317 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3318 ** all calls to the interfaces listed here are completed. 3319 ** 3320 ** If an interface fails with SQLITE_MISUSE, that means the interface 3321 ** was invoked incorrectly by the application. In that case, the 3322 ** error code and message may or may not be set. 3323 */ 3324 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3325 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3326 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3327 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3328 SQLITE_API const char *sqlite3_errstr(int); 3329 3330 /* 3331 ** CAPI3REF: Prepared Statement Object 3332 ** KEYWORDS: {prepared statement} {prepared statements} 3333 ** 3334 ** An instance of this object represents a single SQL statement that 3335 ** has been compiled into binary form and is ready to be evaluated. 3336 ** 3337 ** Think of each SQL statement as a separate computer program. The 3338 ** original SQL text is source code. A prepared statement object 3339 ** is the compiled object code. All SQL must be converted into a 3340 ** prepared statement before it can be run. 3341 ** 3342 ** The life-cycle of a prepared statement object usually goes like this: 3343 ** 3344 ** <ol> 3345 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3346 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3347 ** interfaces. 3348 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3349 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3350 ** to step 2. Do this zero or more times. 3351 ** <li> Destroy the object using [sqlite3_finalize()]. 3352 ** </ol> 3353 */ 3354 typedef struct sqlite3_stmt sqlite3_stmt; 3355 3356 /* 3357 ** CAPI3REF: Run-time Limits 3358 ** METHOD: sqlite3 3359 ** 3360 ** ^(This interface allows the size of various constructs to be limited 3361 ** on a connection by connection basis. The first parameter is the 3362 ** [database connection] whose limit is to be set or queried. The 3363 ** second parameter is one of the [limit categories] that define a 3364 ** class of constructs to be size limited. The third parameter is the 3365 ** new limit for that construct.)^ 3366 ** 3367 ** ^If the new limit is a negative number, the limit is unchanged. 3368 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3369 ** [limits | hard upper bound] 3370 ** set at compile-time by a C preprocessor macro called 3371 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3372 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3373 ** ^Attempts to increase a limit above its hard upper bound are 3374 ** silently truncated to the hard upper bound. 3375 ** 3376 ** ^Regardless of whether or not the limit was changed, the 3377 ** [sqlite3_limit()] interface returns the prior value of the limit. 3378 ** ^Hence, to find the current value of a limit without changing it, 3379 ** simply invoke this interface with the third parameter set to -1. 3380 ** 3381 ** Run-time limits are intended for use in applications that manage 3382 ** both their own internal database and also databases that are controlled 3383 ** by untrusted external sources. An example application might be a 3384 ** web browser that has its own databases for storing history and 3385 ** separate databases controlled by JavaScript applications downloaded 3386 ** off the Internet. The internal databases can be given the 3387 ** large, default limits. Databases managed by external sources can 3388 ** be given much smaller limits designed to prevent a denial of service 3389 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3390 ** interface to further control untrusted SQL. The size of the database 3391 ** created by an untrusted script can be contained using the 3392 ** [max_page_count] [PRAGMA]. 3393 ** 3394 ** New run-time limit categories may be added in future releases. 3395 */ 3396 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3397 3398 /* 3399 ** CAPI3REF: Run-Time Limit Categories 3400 ** KEYWORDS: {limit category} {*limit categories} 3401 ** 3402 ** These constants define various performance limits 3403 ** that can be lowered at run-time using [sqlite3_limit()]. 3404 ** The synopsis of the meanings of the various limits is shown below. 3405 ** Additional information is available at [limits | Limits in SQLite]. 3406 ** 3407 ** <dl> 3408 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3409 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3410 ** 3411 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3412 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3413 ** 3414 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3415 ** <dd>The maximum number of columns in a table definition or in the 3416 ** result set of a [SELECT] or the maximum number of columns in an index 3417 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3418 ** 3419 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3420 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3421 ** 3422 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3423 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3424 ** 3425 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3426 ** <dd>The maximum number of instructions in a virtual machine program 3427 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3428 ** the equivalent tries to allocate space for more than this many opcodes 3429 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3430 ** 3431 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3432 ** <dd>The maximum number of arguments on a function.</dd>)^ 3433 ** 3434 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3435 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3436 ** 3437 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3438 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3439 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3440 ** [GLOB] operators.</dd>)^ 3441 ** 3442 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3443 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3444 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3445 ** 3446 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3447 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3448 ** 3449 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3450 ** <dd>The maximum number of auxiliary worker threads that a single 3451 ** [prepared statement] may start.</dd>)^ 3452 ** </dl> 3453 */ 3454 #define SQLITE_LIMIT_LENGTH 0 3455 #define SQLITE_LIMIT_SQL_LENGTH 1 3456 #define SQLITE_LIMIT_COLUMN 2 3457 #define SQLITE_LIMIT_EXPR_DEPTH 3 3458 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3459 #define SQLITE_LIMIT_VDBE_OP 5 3460 #define SQLITE_LIMIT_FUNCTION_ARG 6 3461 #define SQLITE_LIMIT_ATTACHED 7 3462 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3463 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3464 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3465 #define SQLITE_LIMIT_WORKER_THREADS 11 3466 3467 3468 /* 3469 ** CAPI3REF: Compiling An SQL Statement 3470 ** KEYWORDS: {SQL statement compiler} 3471 ** METHOD: sqlite3 3472 ** CONSTRUCTOR: sqlite3_stmt 3473 ** 3474 ** To execute an SQL query, it must first be compiled into a byte-code 3475 ** program using one of these routines. 3476 ** 3477 ** The first argument, "db", is a [database connection] obtained from a 3478 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3479 ** [sqlite3_open16()]. The database connection must not have been closed. 3480 ** 3481 ** The second argument, "zSql", is the statement to be compiled, encoded 3482 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3483 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3484 ** use UTF-16. 3485 ** 3486 ** ^If the nByte argument is negative, then zSql is read up to the 3487 ** first zero terminator. ^If nByte is positive, then it is the 3488 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3489 ** statement is generated. 3490 ** If the caller knows that the supplied string is nul-terminated, then 3491 ** there is a small performance advantage to passing an nByte parameter that 3492 ** is the number of bytes in the input string <i>including</i> 3493 ** the nul-terminator. 3494 ** 3495 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3496 ** past the end of the first SQL statement in zSql. These routines only 3497 ** compile the first statement in zSql, so *pzTail is left pointing to 3498 ** what remains uncompiled. 3499 ** 3500 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3501 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3502 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3503 ** string or a comment) then *ppStmt is set to NULL. 3504 ** The calling procedure is responsible for deleting the compiled 3505 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3506 ** ppStmt may not be NULL. 3507 ** 3508 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3509 ** otherwise an [error code] is returned. 3510 ** 3511 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3512 ** recommended for all new programs. The two older interfaces are retained 3513 ** for backwards compatibility, but their use is discouraged. 3514 ** ^In the "v2" interfaces, the prepared statement 3515 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3516 ** original SQL text. This causes the [sqlite3_step()] interface to 3517 ** behave differently in three ways: 3518 ** 3519 ** <ol> 3520 ** <li> 3521 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3522 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3523 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3524 ** retries will occur before sqlite3_step() gives up and returns an error. 3525 ** </li> 3526 ** 3527 ** <li> 3528 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3529 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3530 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3531 ** and the application would have to make a second call to [sqlite3_reset()] 3532 ** in order to find the underlying cause of the problem. With the "v2" prepare 3533 ** interfaces, the underlying reason for the error is returned immediately. 3534 ** </li> 3535 ** 3536 ** <li> 3537 ** ^If the specific value bound to [parameter | host parameter] in the 3538 ** WHERE clause might influence the choice of query plan for a statement, 3539 ** then the statement will be automatically recompiled, as if there had been 3540 ** a schema change, on the first [sqlite3_step()] call following any change 3541 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3542 ** ^The specific value of WHERE-clause [parameter] might influence the 3543 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3544 ** or [GLOB] operator or if the parameter is compared to an indexed column 3545 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3546 ** </li> 3547 ** </ol> 3548 */ 3549 SQLITE_API int sqlite3_prepare( 3550 sqlite3 *db, /* Database handle */ 3551 const char *zSql, /* SQL statement, UTF-8 encoded */ 3552 int nByte, /* Maximum length of zSql in bytes. */ 3553 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3554 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3555 ); 3556 SQLITE_API int sqlite3_prepare_v2( 3557 sqlite3 *db, /* Database handle */ 3558 const char *zSql, /* SQL statement, UTF-8 encoded */ 3559 int nByte, /* Maximum length of zSql in bytes. */ 3560 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3561 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3562 ); 3563 SQLITE_API int sqlite3_prepare16( 3564 sqlite3 *db, /* Database handle */ 3565 const void *zSql, /* SQL statement, UTF-16 encoded */ 3566 int nByte, /* Maximum length of zSql in bytes. */ 3567 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3568 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3569 ); 3570 SQLITE_API int sqlite3_prepare16_v2( 3571 sqlite3 *db, /* Database handle */ 3572 const void *zSql, /* SQL statement, UTF-16 encoded */ 3573 int nByte, /* Maximum length of zSql in bytes. */ 3574 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3575 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3576 ); 3577 3578 /* 3579 ** CAPI3REF: Retrieving Statement SQL 3580 ** METHOD: sqlite3_stmt 3581 ** 3582 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3583 ** SQL text used to create [prepared statement] P if P was 3584 ** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3585 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3586 ** string containing the SQL text of prepared statement P with 3587 ** [bound parameters] expanded. 3588 ** 3589 ** ^(For example, if a prepared statement is created using the SQL 3590 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3591 ** and parameter :xyz is unbound, then sqlite3_sql() will return 3592 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3593 ** will return "SELECT 2345,NULL".)^ 3594 ** 3595 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3596 ** is available to hold the result, or if the result would exceed the 3597 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3598 ** 3599 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3600 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3601 ** option causes sqlite3_expanded_sql() to always return NULL. 3602 ** 3603 ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3604 ** automatically freed when the prepared statement is finalized. 3605 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3606 ** is obtained from [sqlite3_malloc()] and must be free by the application 3607 ** by passing it to [sqlite3_free()]. 3608 */ 3609 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3610 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3611 3612 /* 3613 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3614 ** METHOD: sqlite3_stmt 3615 ** 3616 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3617 ** and only if the [prepared statement] X makes no direct changes to 3618 ** the content of the database file. 3619 ** 3620 ** Note that [application-defined SQL functions] or 3621 ** [virtual tables] might change the database indirectly as a side effect. 3622 ** ^(For example, if an application defines a function "eval()" that 3623 ** calls [sqlite3_exec()], then the following SQL statement would 3624 ** change the database file through side-effects: 3625 ** 3626 ** <blockquote><pre> 3627 ** SELECT eval('DELETE FROM t1') FROM t2; 3628 ** </pre></blockquote> 3629 ** 3630 ** But because the [SELECT] statement does not change the database file 3631 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3632 ** 3633 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3634 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3635 ** since the statements themselves do not actually modify the database but 3636 ** rather they control the timing of when other statements modify the 3637 ** database. ^The [ATTACH] and [DETACH] statements also cause 3638 ** sqlite3_stmt_readonly() to return true since, while those statements 3639 ** change the configuration of a database connection, they do not make 3640 ** changes to the content of the database files on disk. 3641 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3642 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3643 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3644 ** sqlite3_stmt_readonly() returns false for those commands. 3645 */ 3646 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3647 3648 /* 3649 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3650 ** METHOD: sqlite3_stmt 3651 ** 3652 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3653 ** [prepared statement] S has been stepped at least once using 3654 ** [sqlite3_step(S)] but has neither run to completion (returned 3655 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3656 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3657 ** interface returns false if S is a NULL pointer. If S is not a 3658 ** NULL pointer and is not a pointer to a valid [prepared statement] 3659 ** object, then the behavior is undefined and probably undesirable. 3660 ** 3661 ** This interface can be used in combination [sqlite3_next_stmt()] 3662 ** to locate all prepared statements associated with a database 3663 ** connection that are in need of being reset. This can be used, 3664 ** for example, in diagnostic routines to search for prepared 3665 ** statements that are holding a transaction open. 3666 */ 3667 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3668 3669 /* 3670 ** CAPI3REF: Dynamically Typed Value Object 3671 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3672 ** 3673 ** SQLite uses the sqlite3_value object to represent all values 3674 ** that can be stored in a database table. SQLite uses dynamic typing 3675 ** for the values it stores. ^Values stored in sqlite3_value objects 3676 ** can be integers, floating point values, strings, BLOBs, or NULL. 3677 ** 3678 ** An sqlite3_value object may be either "protected" or "unprotected". 3679 ** Some interfaces require a protected sqlite3_value. Other interfaces 3680 ** will accept either a protected or an unprotected sqlite3_value. 3681 ** Every interface that accepts sqlite3_value arguments specifies 3682 ** whether or not it requires a protected sqlite3_value. The 3683 ** [sqlite3_value_dup()] interface can be used to construct a new 3684 ** protected sqlite3_value from an unprotected sqlite3_value. 3685 ** 3686 ** The terms "protected" and "unprotected" refer to whether or not 3687 ** a mutex is held. An internal mutex is held for a protected 3688 ** sqlite3_value object but no mutex is held for an unprotected 3689 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3690 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3691 ** or if SQLite is run in one of reduced mutex modes 3692 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3693 ** then there is no distinction between protected and unprotected 3694 ** sqlite3_value objects and they can be used interchangeably. However, 3695 ** for maximum code portability it is recommended that applications 3696 ** still make the distinction between protected and unprotected 3697 ** sqlite3_value objects even when not strictly required. 3698 ** 3699 ** ^The sqlite3_value objects that are passed as parameters into the 3700 ** implementation of [application-defined SQL functions] are protected. 3701 ** ^The sqlite3_value object returned by 3702 ** [sqlite3_column_value()] is unprotected. 3703 ** Unprotected sqlite3_value objects may only be used with 3704 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3705 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3706 ** interfaces require protected sqlite3_value objects. 3707 */ 3708 typedef struct Mem sqlite3_value; 3709 3710 /* 3711 ** CAPI3REF: SQL Function Context Object 3712 ** 3713 ** The context in which an SQL function executes is stored in an 3714 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3715 ** is always first parameter to [application-defined SQL functions]. 3716 ** The application-defined SQL function implementation will pass this 3717 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3718 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3719 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3720 ** and/or [sqlite3_set_auxdata()]. 3721 */ 3722 typedef struct sqlite3_context sqlite3_context; 3723 3724 /* 3725 ** CAPI3REF: Binding Values To Prepared Statements 3726 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3727 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3728 ** METHOD: sqlite3_stmt 3729 ** 3730 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3731 ** literals may be replaced by a [parameter] that matches one of following 3732 ** templates: 3733 ** 3734 ** <ul> 3735 ** <li> ? 3736 ** <li> ?NNN 3737 ** <li> :VVV 3738 ** <li> @VVV 3739 ** <li> $VVV 3740 ** </ul> 3741 ** 3742 ** In the templates above, NNN represents an integer literal, 3743 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3744 ** parameters (also called "host parameter names" or "SQL parameters") 3745 ** can be set using the sqlite3_bind_*() routines defined here. 3746 ** 3747 ** ^The first argument to the sqlite3_bind_*() routines is always 3748 ** a pointer to the [sqlite3_stmt] object returned from 3749 ** [sqlite3_prepare_v2()] or its variants. 3750 ** 3751 ** ^The second argument is the index of the SQL parameter to be set. 3752 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3753 ** SQL parameter is used more than once, second and subsequent 3754 ** occurrences have the same index as the first occurrence. 3755 ** ^The index for named parameters can be looked up using the 3756 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3757 ** for "?NNN" parameters is the value of NNN. 3758 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3759 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3760 ** 3761 ** ^The third argument is the value to bind to the parameter. 3762 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3763 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3764 ** is ignored and the end result is the same as sqlite3_bind_null(). 3765 ** 3766 ** ^(In those routines that have a fourth argument, its value is the 3767 ** number of bytes in the parameter. To be clear: the value is the 3768 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3769 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3770 ** is negative, then the length of the string is 3771 ** the number of bytes up to the first zero terminator. 3772 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3773 ** the behavior is undefined. 3774 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3775 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3776 ** that parameter must be the byte offset 3777 ** where the NUL terminator would occur assuming the string were NUL 3778 ** terminated. If any NUL characters occur at byte offsets less than 3779 ** the value of the fourth parameter then the resulting string value will 3780 ** contain embedded NULs. The result of expressions involving strings 3781 ** with embedded NULs is undefined. 3782 ** 3783 ** ^The fifth argument to the BLOB and string binding interfaces 3784 ** is a destructor used to dispose of the BLOB or 3785 ** string after SQLite has finished with it. ^The destructor is called 3786 ** to dispose of the BLOB or string even if the call to bind API fails. 3787 ** ^If the fifth argument is 3788 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3789 ** information is in static, unmanaged space and does not need to be freed. 3790 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3791 ** SQLite makes its own private copy of the data immediately, before 3792 ** the sqlite3_bind_*() routine returns. 3793 ** 3794 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3795 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3796 ** to specify the encoding of the text in the third parameter. If 3797 ** the sixth argument to sqlite3_bind_text64() is not one of the 3798 ** allowed values shown above, or if the text encoding is different 3799 ** from the encoding specified by the sixth parameter, then the behavior 3800 ** is undefined. 3801 ** 3802 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3803 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3804 ** (just an integer to hold its size) while it is being processed. 3805 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3806 ** content is later written using 3807 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3808 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3809 ** 3810 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3811 ** for the [prepared statement] or with a prepared statement for which 3812 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3813 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3814 ** routine is passed a [prepared statement] that has been finalized, the 3815 ** result is undefined and probably harmful. 3816 ** 3817 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3818 ** ^Unbound parameters are interpreted as NULL. 3819 ** 3820 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3821 ** [error code] if anything goes wrong. 3822 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3823 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3824 ** [SQLITE_MAX_LENGTH]. 3825 ** ^[SQLITE_RANGE] is returned if the parameter 3826 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3827 ** 3828 ** See also: [sqlite3_bind_parameter_count()], 3829 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3830 */ 3831 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3832 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3833 void(*)(void*)); 3834 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3835 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3836 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3837 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3838 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3839 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3840 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3841 void(*)(void*), unsigned char encoding); 3842 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3843 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3844 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3845 3846 /* 3847 ** CAPI3REF: Number Of SQL Parameters 3848 ** METHOD: sqlite3_stmt 3849 ** 3850 ** ^This routine can be used to find the number of [SQL parameters] 3851 ** in a [prepared statement]. SQL parameters are tokens of the 3852 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3853 ** placeholders for values that are [sqlite3_bind_blob | bound] 3854 ** to the parameters at a later time. 3855 ** 3856 ** ^(This routine actually returns the index of the largest (rightmost) 3857 ** parameter. For all forms except ?NNN, this will correspond to the 3858 ** number of unique parameters. If parameters of the ?NNN form are used, 3859 ** there may be gaps in the list.)^ 3860 ** 3861 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3862 ** [sqlite3_bind_parameter_name()], and 3863 ** [sqlite3_bind_parameter_index()]. 3864 */ 3865 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3866 3867 /* 3868 ** CAPI3REF: Name Of A Host Parameter 3869 ** METHOD: sqlite3_stmt 3870 ** 3871 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3872 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3873 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3874 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3875 ** respectively. 3876 ** In other words, the initial ":" or "$" or "@" or "?" 3877 ** is included as part of the name.)^ 3878 ** ^Parameters of the form "?" without a following integer have no name 3879 ** and are referred to as "nameless" or "anonymous parameters". 3880 ** 3881 ** ^The first host parameter has an index of 1, not 0. 3882 ** 3883 ** ^If the value N is out of range or if the N-th parameter is 3884 ** nameless, then NULL is returned. ^The returned string is 3885 ** always in UTF-8 encoding even if the named parameter was 3886 ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3887 ** [sqlite3_prepare16_v2()]. 3888 ** 3889 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3890 ** [sqlite3_bind_parameter_count()], and 3891 ** [sqlite3_bind_parameter_index()]. 3892 */ 3893 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3894 3895 /* 3896 ** CAPI3REF: Index Of A Parameter With A Given Name 3897 ** METHOD: sqlite3_stmt 3898 ** 3899 ** ^Return the index of an SQL parameter given its name. ^The 3900 ** index value returned is suitable for use as the second 3901 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3902 ** is returned if no matching parameter is found. ^The parameter 3903 ** name must be given in UTF-8 even if the original statement 3904 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3905 ** 3906 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3907 ** [sqlite3_bind_parameter_count()], and 3908 ** [sqlite3_bind_parameter_name()]. 3909 */ 3910 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3911 3912 /* 3913 ** CAPI3REF: Reset All Bindings On A Prepared Statement 3914 ** METHOD: sqlite3_stmt 3915 ** 3916 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3917 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3918 ** ^Use this routine to reset all host parameters to NULL. 3919 */ 3920 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3921 3922 /* 3923 ** CAPI3REF: Number Of Columns In A Result Set 3924 ** METHOD: sqlite3_stmt 3925 ** 3926 ** ^Return the number of columns in the result set returned by the 3927 ** [prepared statement]. ^If this routine returns 0, that means the 3928 ** [prepared statement] returns no data (for example an [UPDATE]). 3929 ** ^However, just because this routine returns a positive number does not 3930 ** mean that one or more rows of data will be returned. ^A SELECT statement 3931 ** will always have a positive sqlite3_column_count() but depending on the 3932 ** WHERE clause constraints and the table content, it might return no rows. 3933 ** 3934 ** See also: [sqlite3_data_count()] 3935 */ 3936 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3937 3938 /* 3939 ** CAPI3REF: Column Names In A Result Set 3940 ** METHOD: sqlite3_stmt 3941 ** 3942 ** ^These routines return the name assigned to a particular column 3943 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3944 ** interface returns a pointer to a zero-terminated UTF-8 string 3945 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3946 ** UTF-16 string. ^The first parameter is the [prepared statement] 3947 ** that implements the [SELECT] statement. ^The second parameter is the 3948 ** column number. ^The leftmost column is number 0. 3949 ** 3950 ** ^The returned string pointer is valid until either the [prepared statement] 3951 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3952 ** reprepared by the first call to [sqlite3_step()] for a particular run 3953 ** or until the next call to 3954 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3955 ** 3956 ** ^If sqlite3_malloc() fails during the processing of either routine 3957 ** (for example during a conversion from UTF-8 to UTF-16) then a 3958 ** NULL pointer is returned. 3959 ** 3960 ** ^The name of a result column is the value of the "AS" clause for 3961 ** that column, if there is an AS clause. If there is no AS clause 3962 ** then the name of the column is unspecified and may change from 3963 ** one release of SQLite to the next. 3964 */ 3965 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 3966 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3967 3968 /* 3969 ** CAPI3REF: Source Of Data In A Query Result 3970 ** METHOD: sqlite3_stmt 3971 ** 3972 ** ^These routines provide a means to determine the database, table, and 3973 ** table column that is the origin of a particular result column in 3974 ** [SELECT] statement. 3975 ** ^The name of the database or table or column can be returned as 3976 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3977 ** the database name, the _table_ routines return the table name, and 3978 ** the origin_ routines return the column name. 3979 ** ^The returned string is valid until the [prepared statement] is destroyed 3980 ** using [sqlite3_finalize()] or until the statement is automatically 3981 ** reprepared by the first call to [sqlite3_step()] for a particular run 3982 ** or until the same information is requested 3983 ** again in a different encoding. 3984 ** 3985 ** ^The names returned are the original un-aliased names of the 3986 ** database, table, and column. 3987 ** 3988 ** ^The first argument to these interfaces is a [prepared statement]. 3989 ** ^These functions return information about the Nth result column returned by 3990 ** the statement, where N is the second function argument. 3991 ** ^The left-most column is column 0 for these routines. 3992 ** 3993 ** ^If the Nth column returned by the statement is an expression or 3994 ** subquery and is not a column value, then all of these functions return 3995 ** NULL. ^These routine might also return NULL if a memory allocation error 3996 ** occurs. ^Otherwise, they return the name of the attached database, table, 3997 ** or column that query result column was extracted from. 3998 ** 3999 ** ^As with all other SQLite APIs, those whose names end with "16" return 4000 ** UTF-16 encoded strings and the other functions return UTF-8. 4001 ** 4002 ** ^These APIs are only available if the library was compiled with the 4003 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4004 ** 4005 ** If two or more threads call one or more of these routines against the same 4006 ** prepared statement and column at the same time then the results are 4007 ** undefined. 4008 ** 4009 ** If two or more threads call one or more 4010 ** [sqlite3_column_database_name | column metadata interfaces] 4011 ** for the same [prepared statement] and result column 4012 ** at the same time then the results are undefined. 4013 */ 4014 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4015 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4016 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4017 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4018 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4019 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4020 4021 /* 4022 ** CAPI3REF: Declared Datatype Of A Query Result 4023 ** METHOD: sqlite3_stmt 4024 ** 4025 ** ^(The first parameter is a [prepared statement]. 4026 ** If this statement is a [SELECT] statement and the Nth column of the 4027 ** returned result set of that [SELECT] is a table column (not an 4028 ** expression or subquery) then the declared type of the table 4029 ** column is returned.)^ ^If the Nth column of the result set is an 4030 ** expression or subquery, then a NULL pointer is returned. 4031 ** ^The returned string is always UTF-8 encoded. 4032 ** 4033 ** ^(For example, given the database schema: 4034 ** 4035 ** CREATE TABLE t1(c1 VARIANT); 4036 ** 4037 ** and the following statement to be compiled: 4038 ** 4039 ** SELECT c1 + 1, c1 FROM t1; 4040 ** 4041 ** this routine would return the string "VARIANT" for the second result 4042 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4043 ** 4044 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4045 ** is declared to contain a particular type does not mean that the 4046 ** data stored in that column is of the declared type. SQLite is 4047 ** strongly typed, but the typing is dynamic not static. ^Type 4048 ** is associated with individual values, not with the containers 4049 ** used to hold those values. 4050 */ 4051 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4052 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4053 4054 /* 4055 ** CAPI3REF: Evaluate An SQL Statement 4056 ** METHOD: sqlite3_stmt 4057 ** 4058 ** After a [prepared statement] has been prepared using either 4059 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 4060 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4061 ** must be called one or more times to evaluate the statement. 4062 ** 4063 ** The details of the behavior of the sqlite3_step() interface depend 4064 ** on whether the statement was prepared using the newer "v2" interface 4065 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 4066 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4067 ** new "v2" interface is recommended for new applications but the legacy 4068 ** interface will continue to be supported. 4069 ** 4070 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4071 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4072 ** ^With the "v2" interface, any of the other [result codes] or 4073 ** [extended result codes] might be returned as well. 4074 ** 4075 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4076 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4077 ** or occurs outside of an explicit transaction, then you can retry the 4078 ** statement. If the statement is not a [COMMIT] and occurs within an 4079 ** explicit transaction then you should rollback the transaction before 4080 ** continuing. 4081 ** 4082 ** ^[SQLITE_DONE] means that the statement has finished executing 4083 ** successfully. sqlite3_step() should not be called again on this virtual 4084 ** machine without first calling [sqlite3_reset()] to reset the virtual 4085 ** machine back to its initial state. 4086 ** 4087 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4088 ** is returned each time a new row of data is ready for processing by the 4089 ** caller. The values may be accessed using the [column access functions]. 4090 ** sqlite3_step() is called again to retrieve the next row of data. 4091 ** 4092 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4093 ** violation) has occurred. sqlite3_step() should not be called again on 4094 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4095 ** ^With the legacy interface, a more specific error code (for example, 4096 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4097 ** can be obtained by calling [sqlite3_reset()] on the 4098 ** [prepared statement]. ^In the "v2" interface, 4099 ** the more specific error code is returned directly by sqlite3_step(). 4100 ** 4101 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4102 ** Perhaps it was called on a [prepared statement] that has 4103 ** already been [sqlite3_finalize | finalized] or on one that had 4104 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4105 ** be the case that the same database connection is being used by two or 4106 ** more threads at the same moment in time. 4107 ** 4108 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4109 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4110 ** other than [SQLITE_ROW] before any subsequent invocation of 4111 ** sqlite3_step(). Failure to reset the prepared statement using 4112 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4113 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4114 ** sqlite3_step() began 4115 ** calling [sqlite3_reset()] automatically in this circumstance rather 4116 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4117 ** break because any application that ever receives an SQLITE_MISUSE error 4118 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4119 ** can be used to restore the legacy behavior. 4120 ** 4121 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4122 ** API always returns a generic error code, [SQLITE_ERROR], following any 4123 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4124 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4125 ** specific [error codes] that better describes the error. 4126 ** We admit that this is a goofy design. The problem has been fixed 4127 ** with the "v2" interface. If you prepare all of your SQL statements 4128 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 4129 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4130 ** then the more specific [error codes] are returned directly 4131 ** by sqlite3_step(). The use of the "v2" interface is recommended. 4132 */ 4133 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4134 4135 /* 4136 ** CAPI3REF: Number of columns in a result set 4137 ** METHOD: sqlite3_stmt 4138 ** 4139 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4140 ** current row of the result set of [prepared statement] P. 4141 ** ^If prepared statement P does not have results ready to return 4142 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4143 ** interfaces) then sqlite3_data_count(P) returns 0. 4144 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4145 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4146 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4147 ** will return non-zero if previous call to [sqlite3_step](P) returned 4148 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4149 ** where it always returns zero since each step of that multi-step 4150 ** pragma returns 0 columns of data. 4151 ** 4152 ** See also: [sqlite3_column_count()] 4153 */ 4154 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4155 4156 /* 4157 ** CAPI3REF: Fundamental Datatypes 4158 ** KEYWORDS: SQLITE_TEXT 4159 ** 4160 ** ^(Every value in SQLite has one of five fundamental datatypes: 4161 ** 4162 ** <ul> 4163 ** <li> 64-bit signed integer 4164 ** <li> 64-bit IEEE floating point number 4165 ** <li> string 4166 ** <li> BLOB 4167 ** <li> NULL 4168 ** </ul>)^ 4169 ** 4170 ** These constants are codes for each of those types. 4171 ** 4172 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4173 ** for a completely different meaning. Software that links against both 4174 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4175 ** SQLITE_TEXT. 4176 */ 4177 #define SQLITE_INTEGER 1 4178 #define SQLITE_FLOAT 2 4179 #define SQLITE_BLOB 4 4180 #define SQLITE_NULL 5 4181 #ifdef SQLITE_TEXT 4182 # undef SQLITE_TEXT 4183 #else 4184 # define SQLITE_TEXT 3 4185 #endif 4186 #define SQLITE3_TEXT 3 4187 4188 /* 4189 ** CAPI3REF: Result Values From A Query 4190 ** KEYWORDS: {column access functions} 4191 ** METHOD: sqlite3_stmt 4192 ** 4193 ** ^These routines return information about a single column of the current 4194 ** result row of a query. ^In every case the first argument is a pointer 4195 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4196 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4197 ** and the second argument is the index of the column for which information 4198 ** should be returned. ^The leftmost column of the result set has the index 0. 4199 ** ^The number of columns in the result can be determined using 4200 ** [sqlite3_column_count()]. 4201 ** 4202 ** If the SQL statement does not currently point to a valid row, or if the 4203 ** column index is out of range, the result is undefined. 4204 ** These routines may only be called when the most recent call to 4205 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4206 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4207 ** If any of these routines are called after [sqlite3_reset()] or 4208 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4209 ** something other than [SQLITE_ROW], the results are undefined. 4210 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4211 ** are called from a different thread while any of these routines 4212 ** are pending, then the results are undefined. 4213 ** 4214 ** ^The sqlite3_column_type() routine returns the 4215 ** [SQLITE_INTEGER | datatype code] for the initial data type 4216 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4217 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 4218 ** returned by sqlite3_column_type() is only meaningful if no type 4219 ** conversions have occurred as described below. After a type conversion, 4220 ** the value returned by sqlite3_column_type() is undefined. Future 4221 ** versions of SQLite may change the behavior of sqlite3_column_type() 4222 ** following a type conversion. 4223 ** 4224 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4225 ** routine returns the number of bytes in that BLOB or string. 4226 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4227 ** the string to UTF-8 and then returns the number of bytes. 4228 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4229 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4230 ** the number of bytes in that string. 4231 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4232 ** 4233 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4234 ** routine returns the number of bytes in that BLOB or string. 4235 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4236 ** the string to UTF-16 and then returns the number of bytes. 4237 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4238 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4239 ** the number of bytes in that string. 4240 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4241 ** 4242 ** ^The values returned by [sqlite3_column_bytes()] and 4243 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4244 ** of the string. ^For clarity: the values returned by 4245 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4246 ** bytes in the string, not the number of characters. 4247 ** 4248 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4249 ** even empty strings, are always zero-terminated. ^The return 4250 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4251 ** 4252 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4253 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4254 ** an unprotected sqlite3_value object may only be used safely with 4255 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4256 ** If the [unprotected sqlite3_value] object returned by 4257 ** [sqlite3_column_value()] is used in any other way, including calls 4258 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4259 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4260 ** 4261 ** These routines attempt to convert the value where appropriate. ^For 4262 ** example, if the internal representation is FLOAT and a text result 4263 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4264 ** conversion automatically. ^(The following table details the conversions 4265 ** that are applied: 4266 ** 4267 ** <blockquote> 4268 ** <table border="1"> 4269 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4270 ** 4271 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4272 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4273 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4274 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4275 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4276 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4277 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4278 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4279 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4280 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4281 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4282 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4283 ** <tr><td> TEXT <td> BLOB <td> No change 4284 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4285 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4286 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4287 ** </table> 4288 ** </blockquote>)^ 4289 ** 4290 ** Note that when type conversions occur, pointers returned by prior 4291 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4292 ** sqlite3_column_text16() may be invalidated. 4293 ** Type conversions and pointer invalidations might occur 4294 ** in the following cases: 4295 ** 4296 ** <ul> 4297 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4298 ** sqlite3_column_text16() is called. A zero-terminator might 4299 ** need to be added to the string.</li> 4300 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4301 ** sqlite3_column_text16() is called. The content must be converted 4302 ** to UTF-16.</li> 4303 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4304 ** sqlite3_column_text() is called. The content must be converted 4305 ** to UTF-8.</li> 4306 ** </ul> 4307 ** 4308 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4309 ** not invalidate a prior pointer, though of course the content of the buffer 4310 ** that the prior pointer references will have been modified. Other kinds 4311 ** of conversion are done in place when it is possible, but sometimes they 4312 ** are not possible and in those cases prior pointers are invalidated. 4313 ** 4314 ** The safest policy is to invoke these routines 4315 ** in one of the following ways: 4316 ** 4317 ** <ul> 4318 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4319 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4320 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4321 ** </ul> 4322 ** 4323 ** In other words, you should call sqlite3_column_text(), 4324 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4325 ** into the desired format, then invoke sqlite3_column_bytes() or 4326 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4327 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4328 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4329 ** with calls to sqlite3_column_bytes(). 4330 ** 4331 ** ^The pointers returned are valid until a type conversion occurs as 4332 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4333 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4334 ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4335 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4336 ** [sqlite3_free()]. 4337 ** 4338 ** ^(If a memory allocation error occurs during the evaluation of any 4339 ** of these routines, a default value is returned. The default value 4340 ** is either the integer 0, the floating point number 0.0, or a NULL 4341 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4342 ** [SQLITE_NOMEM].)^ 4343 */ 4344 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4345 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4346 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4347 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4348 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4349 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4350 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4351 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4352 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4353 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4354 4355 /* 4356 ** CAPI3REF: Destroy A Prepared Statement Object 4357 ** DESTRUCTOR: sqlite3_stmt 4358 ** 4359 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4360 ** ^If the most recent evaluation of the statement encountered no errors 4361 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4362 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4363 ** sqlite3_finalize(S) returns the appropriate [error code] or 4364 ** [extended error code]. 4365 ** 4366 ** ^The sqlite3_finalize(S) routine can be called at any point during 4367 ** the life cycle of [prepared statement] S: 4368 ** before statement S is ever evaluated, after 4369 ** one or more calls to [sqlite3_reset()], or after any call 4370 ** to [sqlite3_step()] regardless of whether or not the statement has 4371 ** completed execution. 4372 ** 4373 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4374 ** 4375 ** The application must finalize every [prepared statement] in order to avoid 4376 ** resource leaks. It is a grievous error for the application to try to use 4377 ** a prepared statement after it has been finalized. Any use of a prepared 4378 ** statement after it has been finalized can result in undefined and 4379 ** undesirable behavior such as segfaults and heap corruption. 4380 */ 4381 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4382 4383 /* 4384 ** CAPI3REF: Reset A Prepared Statement Object 4385 ** METHOD: sqlite3_stmt 4386 ** 4387 ** The sqlite3_reset() function is called to reset a [prepared statement] 4388 ** object back to its initial state, ready to be re-executed. 4389 ** ^Any SQL statement variables that had values bound to them using 4390 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4391 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4392 ** 4393 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4394 ** back to the beginning of its program. 4395 ** 4396 ** ^If the most recent call to [sqlite3_step(S)] for the 4397 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4398 ** or if [sqlite3_step(S)] has never before been called on S, 4399 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4400 ** 4401 ** ^If the most recent call to [sqlite3_step(S)] for the 4402 ** [prepared statement] S indicated an error, then 4403 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4404 ** 4405 ** ^The [sqlite3_reset(S)] interface does not change the values 4406 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4407 */ 4408 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4409 4410 /* 4411 ** CAPI3REF: Create Or Redefine SQL Functions 4412 ** KEYWORDS: {function creation routines} 4413 ** KEYWORDS: {application-defined SQL function} 4414 ** KEYWORDS: {application-defined SQL functions} 4415 ** METHOD: sqlite3 4416 ** 4417 ** ^These functions (collectively known as "function creation routines") 4418 ** are used to add SQL functions or aggregates or to redefine the behavior 4419 ** of existing SQL functions or aggregates. The only differences between 4420 ** these routines are the text encoding expected for 4421 ** the second parameter (the name of the function being created) 4422 ** and the presence or absence of a destructor callback for 4423 ** the application data pointer. 4424 ** 4425 ** ^The first parameter is the [database connection] to which the SQL 4426 ** function is to be added. ^If an application uses more than one database 4427 ** connection then application-defined SQL functions must be added 4428 ** to each database connection separately. 4429 ** 4430 ** ^The second parameter is the name of the SQL function to be created or 4431 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4432 ** representation, exclusive of the zero-terminator. ^Note that the name 4433 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4434 ** ^Any attempt to create a function with a longer name 4435 ** will result in [SQLITE_MISUSE] being returned. 4436 ** 4437 ** ^The third parameter (nArg) 4438 ** is the number of arguments that the SQL function or 4439 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4440 ** aggregate may take any number of arguments between 0 and the limit 4441 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4442 ** parameter is less than -1 or greater than 127 then the behavior is 4443 ** undefined. 4444 ** 4445 ** ^The fourth parameter, eTextRep, specifies what 4446 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4447 ** its parameters. The application should set this parameter to 4448 ** [SQLITE_UTF16LE] if the function implementation invokes 4449 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4450 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4451 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4452 ** otherwise. ^The same SQL function may be registered multiple times using 4453 ** different preferred text encodings, with different implementations for 4454 ** each encoding. 4455 ** ^When multiple implementations of the same function are available, SQLite 4456 ** will pick the one that involves the least amount of data conversion. 4457 ** 4458 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4459 ** to signal that the function will always return the same result given 4460 ** the same inputs within a single SQL statement. Most SQL functions are 4461 ** deterministic. The built-in [random()] SQL function is an example of a 4462 ** function that is not deterministic. The SQLite query planner is able to 4463 ** perform additional optimizations on deterministic functions, so use 4464 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4465 ** 4466 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4467 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4468 ** 4469 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4470 ** pointers to C-language functions that implement the SQL function or 4471 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4472 ** callback only; NULL pointers must be passed as the xStep and xFinal 4473 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4474 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4475 ** SQL function or aggregate, pass NULL pointers for all three function 4476 ** callbacks. 4477 ** 4478 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4479 ** then it is destructor for the application data pointer. 4480 ** The destructor is invoked when the function is deleted, either by being 4481 ** overloaded or when the database connection closes.)^ 4482 ** ^The destructor is also invoked if the call to 4483 ** sqlite3_create_function_v2() fails. 4484 ** ^When the destructor callback of the tenth parameter is invoked, it 4485 ** is passed a single argument which is a copy of the application data 4486 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4487 ** 4488 ** ^It is permitted to register multiple implementations of the same 4489 ** functions with the same name but with either differing numbers of 4490 ** arguments or differing preferred text encodings. ^SQLite will use 4491 ** the implementation that most closely matches the way in which the 4492 ** SQL function is used. ^A function implementation with a non-negative 4493 ** nArg parameter is a better match than a function implementation with 4494 ** a negative nArg. ^A function where the preferred text encoding 4495 ** matches the database encoding is a better 4496 ** match than a function where the encoding is different. 4497 ** ^A function where the encoding difference is between UTF16le and UTF16be 4498 ** is a closer match than a function where the encoding difference is 4499 ** between UTF8 and UTF16. 4500 ** 4501 ** ^Built-in functions may be overloaded by new application-defined functions. 4502 ** 4503 ** ^An application-defined function is permitted to call other 4504 ** SQLite interfaces. However, such calls must not 4505 ** close the database connection nor finalize or reset the prepared 4506 ** statement in which the function is running. 4507 */ 4508 SQLITE_API int sqlite3_create_function( 4509 sqlite3 *db, 4510 const char *zFunctionName, 4511 int nArg, 4512 int eTextRep, 4513 void *pApp, 4514 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4515 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4516 void (*xFinal)(sqlite3_context*) 4517 ); 4518 SQLITE_API int sqlite3_create_function16( 4519 sqlite3 *db, 4520 const void *zFunctionName, 4521 int nArg, 4522 int eTextRep, 4523 void *pApp, 4524 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4525 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4526 void (*xFinal)(sqlite3_context*) 4527 ); 4528 SQLITE_API int sqlite3_create_function_v2( 4529 sqlite3 *db, 4530 const char *zFunctionName, 4531 int nArg, 4532 int eTextRep, 4533 void *pApp, 4534 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4535 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4536 void (*xFinal)(sqlite3_context*), 4537 void(*xDestroy)(void*) 4538 ); 4539 4540 /* 4541 ** CAPI3REF: Text Encodings 4542 ** 4543 ** These constant define integer codes that represent the various 4544 ** text encodings supported by SQLite. 4545 */ 4546 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4547 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4548 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4549 #define SQLITE_UTF16 4 /* Use native byte order */ 4550 #define SQLITE_ANY 5 /* Deprecated */ 4551 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4552 4553 /* 4554 ** CAPI3REF: Function Flags 4555 ** 4556 ** These constants may be ORed together with the 4557 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4558 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4559 ** [sqlite3_create_function_v2()]. 4560 */ 4561 #define SQLITE_DETERMINISTIC 0x800 4562 4563 /* 4564 ** CAPI3REF: Deprecated Functions 4565 ** DEPRECATED 4566 ** 4567 ** These functions are [deprecated]. In order to maintain 4568 ** backwards compatibility with older code, these functions continue 4569 ** to be supported. However, new applications should avoid 4570 ** the use of these functions. To encourage programmers to avoid 4571 ** these functions, we will not explain what they do. 4572 */ 4573 #ifndef SQLITE_OMIT_DEPRECATED 4574 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4575 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4576 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4577 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4578 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4579 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4580 void*,sqlite3_int64); 4581 #endif 4582 4583 /* 4584 ** CAPI3REF: Obtaining SQL Values 4585 ** METHOD: sqlite3_value 4586 ** 4587 ** The C-language implementation of SQL functions and aggregates uses 4588 ** this set of interface routines to access the parameter values on 4589 ** the function or aggregate. 4590 ** 4591 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4592 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4593 ** define callbacks that implement the SQL functions and aggregates. 4594 ** The 3rd parameter to these callbacks is an array of pointers to 4595 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4596 ** each parameter to the SQL function. These routines are used to 4597 ** extract values from the [sqlite3_value] objects. 4598 ** 4599 ** These routines work only with [protected sqlite3_value] objects. 4600 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4601 ** object results in undefined behavior. 4602 ** 4603 ** ^These routines work just like the corresponding [column access functions] 4604 ** except that these routines take a single [protected sqlite3_value] object 4605 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4606 ** 4607 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4608 ** in the native byte-order of the host machine. ^The 4609 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4610 ** extract UTF-16 strings as big-endian and little-endian respectively. 4611 ** 4612 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4613 ** numeric affinity to the value. This means that an attempt is 4614 ** made to convert the value to an integer or floating point. If 4615 ** such a conversion is possible without loss of information (in other 4616 ** words, if the value is a string that looks like a number) 4617 ** then the conversion is performed. Otherwise no conversion occurs. 4618 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4619 ** 4620 ** Please pay particular attention to the fact that the pointer returned 4621 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4622 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4623 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4624 ** or [sqlite3_value_text16()]. 4625 ** 4626 ** These routines must be called from the same thread as 4627 ** the SQL function that supplied the [sqlite3_value*] parameters. 4628 */ 4629 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4630 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4631 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4632 SQLITE_API double sqlite3_value_double(sqlite3_value*); 4633 SQLITE_API int sqlite3_value_int(sqlite3_value*); 4634 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4635 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4636 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4637 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4638 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4639 SQLITE_API int sqlite3_value_type(sqlite3_value*); 4640 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4641 4642 /* 4643 ** CAPI3REF: Finding The Subtype Of SQL Values 4644 ** METHOD: sqlite3_value 4645 ** 4646 ** The sqlite3_value_subtype(V) function returns the subtype for 4647 ** an [application-defined SQL function] argument V. The subtype 4648 ** information can be used to pass a limited amount of context from 4649 ** one SQL function to another. Use the [sqlite3_result_subtype()] 4650 ** routine to set the subtype for the return value of an SQL function. 4651 ** 4652 ** SQLite makes no use of subtype itself. It merely passes the subtype 4653 ** from the result of one [application-defined SQL function] into the 4654 ** input of another. 4655 */ 4656 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 4657 4658 /* 4659 ** CAPI3REF: Copy And Free SQL Values 4660 ** METHOD: sqlite3_value 4661 ** 4662 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4663 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4664 ** is a [protected sqlite3_value] object even if the input is not. 4665 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4666 ** memory allocation fails. 4667 ** 4668 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4669 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4670 ** then sqlite3_value_free(V) is a harmless no-op. 4671 */ 4672 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4673 SQLITE_API void sqlite3_value_free(sqlite3_value*); 4674 4675 /* 4676 ** CAPI3REF: Obtain Aggregate Function Context 4677 ** METHOD: sqlite3_context 4678 ** 4679 ** Implementations of aggregate SQL functions use this 4680 ** routine to allocate memory for storing their state. 4681 ** 4682 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4683 ** for a particular aggregate function, SQLite 4684 ** allocates N of memory, zeroes out that memory, and returns a pointer 4685 ** to the new memory. ^On second and subsequent calls to 4686 ** sqlite3_aggregate_context() for the same aggregate function instance, 4687 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4688 ** called once for each invocation of the xStep callback and then one 4689 ** last time when the xFinal callback is invoked. ^(When no rows match 4690 ** an aggregate query, the xStep() callback of the aggregate function 4691 ** implementation is never called and xFinal() is called exactly once. 4692 ** In those cases, sqlite3_aggregate_context() might be called for the 4693 ** first time from within xFinal().)^ 4694 ** 4695 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4696 ** when first called if N is less than or equal to zero or if a memory 4697 ** allocate error occurs. 4698 ** 4699 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4700 ** determined by the N parameter on first successful call. Changing the 4701 ** value of N in subsequent call to sqlite3_aggregate_context() within 4702 ** the same aggregate function instance will not resize the memory 4703 ** allocation.)^ Within the xFinal callback, it is customary to set 4704 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4705 ** pointless memory allocations occur. 4706 ** 4707 ** ^SQLite automatically frees the memory allocated by 4708 ** sqlite3_aggregate_context() when the aggregate query concludes. 4709 ** 4710 ** The first parameter must be a copy of the 4711 ** [sqlite3_context | SQL function context] that is the first parameter 4712 ** to the xStep or xFinal callback routine that implements the aggregate 4713 ** function. 4714 ** 4715 ** This routine must be called from the same thread in which 4716 ** the aggregate SQL function is running. 4717 */ 4718 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4719 4720 /* 4721 ** CAPI3REF: User Data For Functions 4722 ** METHOD: sqlite3_context 4723 ** 4724 ** ^The sqlite3_user_data() interface returns a copy of 4725 ** the pointer that was the pUserData parameter (the 5th parameter) 4726 ** of the [sqlite3_create_function()] 4727 ** and [sqlite3_create_function16()] routines that originally 4728 ** registered the application defined function. 4729 ** 4730 ** This routine must be called from the same thread in which 4731 ** the application-defined function is running. 4732 */ 4733 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4734 4735 /* 4736 ** CAPI3REF: Database Connection For Functions 4737 ** METHOD: sqlite3_context 4738 ** 4739 ** ^The sqlite3_context_db_handle() interface returns a copy of 4740 ** the pointer to the [database connection] (the 1st parameter) 4741 ** of the [sqlite3_create_function()] 4742 ** and [sqlite3_create_function16()] routines that originally 4743 ** registered the application defined function. 4744 */ 4745 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4746 4747 /* 4748 ** CAPI3REF: Function Auxiliary Data 4749 ** METHOD: sqlite3_context 4750 ** 4751 ** These functions may be used by (non-aggregate) SQL functions to 4752 ** associate metadata with argument values. If the same value is passed to 4753 ** multiple invocations of the same SQL function during query execution, under 4754 ** some circumstances the associated metadata may be preserved. An example 4755 ** of where this might be useful is in a regular-expression matching 4756 ** function. The compiled version of the regular expression can be stored as 4757 ** metadata associated with the pattern string. 4758 ** Then as long as the pattern string remains the same, 4759 ** the compiled regular expression can be reused on multiple 4760 ** invocations of the same function. 4761 ** 4762 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4763 ** associated by the sqlite3_set_auxdata() function with the Nth argument 4764 ** value to the application-defined function. ^If there is no metadata 4765 ** associated with the function argument, this sqlite3_get_auxdata() interface 4766 ** returns a NULL pointer. 4767 ** 4768 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4769 ** argument of the application-defined function. ^Subsequent 4770 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4771 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4772 ** NULL if the metadata has been discarded. 4773 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4774 ** SQLite will invoke the destructor function X with parameter P exactly 4775 ** once, when the metadata is discarded. 4776 ** SQLite is free to discard the metadata at any time, including: <ul> 4777 ** <li> ^(when the corresponding function parameter changes)^, or 4778 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4779 ** SQL statement)^, or 4780 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4781 ** parameter)^, or 4782 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4783 ** allocation error occurs.)^ </ul> 4784 ** 4785 ** Note the last bullet in particular. The destructor X in 4786 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4787 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4788 ** should be called near the end of the function implementation and the 4789 ** function implementation should not make any use of P after 4790 ** sqlite3_set_auxdata() has been called. 4791 ** 4792 ** ^(In practice, metadata is preserved between function calls for 4793 ** function parameters that are compile-time constants, including literal 4794 ** values and [parameters] and expressions composed from the same.)^ 4795 ** 4796 ** These routines must be called from the same thread in which 4797 ** the SQL function is running. 4798 */ 4799 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 4800 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4801 4802 4803 /* 4804 ** CAPI3REF: Constants Defining Special Destructor Behavior 4805 ** 4806 ** These are special values for the destructor that is passed in as the 4807 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4808 ** argument is SQLITE_STATIC, it means that the content pointer is constant 4809 ** and will never change. It does not need to be destroyed. ^The 4810 ** SQLITE_TRANSIENT value means that the content will likely change in 4811 ** the near future and that SQLite should make its own private copy of 4812 ** the content before returning. 4813 ** 4814 ** The typedef is necessary to work around problems in certain 4815 ** C++ compilers. 4816 */ 4817 typedef void (*sqlite3_destructor_type)(void*); 4818 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4819 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4820 4821 /* 4822 ** CAPI3REF: Setting The Result Of An SQL Function 4823 ** METHOD: sqlite3_context 4824 ** 4825 ** These routines are used by the xFunc or xFinal callbacks that 4826 ** implement SQL functions and aggregates. See 4827 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4828 ** for additional information. 4829 ** 4830 ** These functions work very much like the [parameter binding] family of 4831 ** functions used to bind values to host parameters in prepared statements. 4832 ** Refer to the [SQL parameter] documentation for additional information. 4833 ** 4834 ** ^The sqlite3_result_blob() interface sets the result from 4835 ** an application-defined function to be the BLOB whose content is pointed 4836 ** to by the second parameter and which is N bytes long where N is the 4837 ** third parameter. 4838 ** 4839 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4840 ** interfaces set the result of the application-defined function to be 4841 ** a BLOB containing all zero bytes and N bytes in size. 4842 ** 4843 ** ^The sqlite3_result_double() interface sets the result from 4844 ** an application-defined function to be a floating point value specified 4845 ** by its 2nd argument. 4846 ** 4847 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4848 ** cause the implemented SQL function to throw an exception. 4849 ** ^SQLite uses the string pointed to by the 4850 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4851 ** as the text of an error message. ^SQLite interprets the error 4852 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4853 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4854 ** byte order. ^If the third parameter to sqlite3_result_error() 4855 ** or sqlite3_result_error16() is negative then SQLite takes as the error 4856 ** message all text up through the first zero character. 4857 ** ^If the third parameter to sqlite3_result_error() or 4858 ** sqlite3_result_error16() is non-negative then SQLite takes that many 4859 ** bytes (not characters) from the 2nd parameter as the error message. 4860 ** ^The sqlite3_result_error() and sqlite3_result_error16() 4861 ** routines make a private copy of the error message text before 4862 ** they return. Hence, the calling function can deallocate or 4863 ** modify the text after they return without harm. 4864 ** ^The sqlite3_result_error_code() function changes the error code 4865 ** returned by SQLite as a result of an error in a function. ^By default, 4866 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4867 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4868 ** 4869 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4870 ** error indicating that a string or BLOB is too long to represent. 4871 ** 4872 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4873 ** error indicating that a memory allocation failed. 4874 ** 4875 ** ^The sqlite3_result_int() interface sets the return value 4876 ** of the application-defined function to be the 32-bit signed integer 4877 ** value given in the 2nd argument. 4878 ** ^The sqlite3_result_int64() interface sets the return value 4879 ** of the application-defined function to be the 64-bit signed integer 4880 ** value given in the 2nd argument. 4881 ** 4882 ** ^The sqlite3_result_null() interface sets the return value 4883 ** of the application-defined function to be NULL. 4884 ** 4885 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4886 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4887 ** set the return value of the application-defined function to be 4888 ** a text string which is represented as UTF-8, UTF-16 native byte order, 4889 ** UTF-16 little endian, or UTF-16 big endian, respectively. 4890 ** ^The sqlite3_result_text64() interface sets the return value of an 4891 ** application-defined function to be a text string in an encoding 4892 ** specified by the fifth (and last) parameter, which must be one 4893 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4894 ** ^SQLite takes the text result from the application from 4895 ** the 2nd parameter of the sqlite3_result_text* interfaces. 4896 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4897 ** is negative, then SQLite takes result text from the 2nd parameter 4898 ** through the first zero character. 4899 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4900 ** is non-negative, then as many bytes (not characters) of the text 4901 ** pointed to by the 2nd parameter are taken as the application-defined 4902 ** function result. If the 3rd parameter is non-negative, then it 4903 ** must be the byte offset into the string where the NUL terminator would 4904 ** appear if the string where NUL terminated. If any NUL characters occur 4905 ** in the string at a byte offset that is less than the value of the 3rd 4906 ** parameter, then the resulting string will contain embedded NULs and the 4907 ** result of expressions operating on strings with embedded NULs is undefined. 4908 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4909 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4910 ** function as the destructor on the text or BLOB result when it has 4911 ** finished using that result. 4912 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4913 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4914 ** assumes that the text or BLOB result is in constant space and does not 4915 ** copy the content of the parameter nor call a destructor on the content 4916 ** when it has finished using that result. 4917 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4918 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4919 ** then SQLite makes a copy of the result into space obtained from 4920 ** from [sqlite3_malloc()] before it returns. 4921 ** 4922 ** ^The sqlite3_result_value() interface sets the result of 4923 ** the application-defined function to be a copy of the 4924 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4925 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4926 ** so that the [sqlite3_value] specified in the parameter may change or 4927 ** be deallocated after sqlite3_result_value() returns without harm. 4928 ** ^A [protected sqlite3_value] object may always be used where an 4929 ** [unprotected sqlite3_value] object is required, so either 4930 ** kind of [sqlite3_value] object can be used with this interface. 4931 ** 4932 ** If these routines are called from within the different thread 4933 ** than the one containing the application-defined function that received 4934 ** the [sqlite3_context] pointer, the results are undefined. 4935 */ 4936 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4937 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 4938 sqlite3_uint64,void(*)(void*)); 4939 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4940 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4941 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4942 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4943 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 4944 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 4945 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 4946 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4947 SQLITE_API void sqlite3_result_null(sqlite3_context*); 4948 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4949 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4950 void(*)(void*), unsigned char encoding); 4951 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4952 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4953 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4954 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4955 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 4956 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4957 4958 4959 /* 4960 ** CAPI3REF: Setting The Subtype Of An SQL Function 4961 ** METHOD: sqlite3_context 4962 ** 4963 ** The sqlite3_result_subtype(C,T) function causes the subtype of 4964 ** the result from the [application-defined SQL function] with 4965 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 4966 ** of the subtype T are preserved in current versions of SQLite; 4967 ** higher order bits are discarded. 4968 ** The number of subtype bytes preserved by SQLite might increase 4969 ** in future releases of SQLite. 4970 */ 4971 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 4972 4973 /* 4974 ** CAPI3REF: Define New Collating Sequences 4975 ** METHOD: sqlite3 4976 ** 4977 ** ^These functions add, remove, or modify a [collation] associated 4978 ** with the [database connection] specified as the first argument. 4979 ** 4980 ** ^The name of the collation is a UTF-8 string 4981 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4982 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4983 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4984 ** considered to be the same name. 4985 ** 4986 ** ^(The third argument (eTextRep) must be one of the constants: 4987 ** <ul> 4988 ** <li> [SQLITE_UTF8], 4989 ** <li> [SQLITE_UTF16LE], 4990 ** <li> [SQLITE_UTF16BE], 4991 ** <li> [SQLITE_UTF16], or 4992 ** <li> [SQLITE_UTF16_ALIGNED]. 4993 ** </ul>)^ 4994 ** ^The eTextRep argument determines the encoding of strings passed 4995 ** to the collating function callback, xCallback. 4996 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4997 ** force strings to be UTF16 with native byte order. 4998 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4999 ** on an even byte address. 5000 ** 5001 ** ^The fourth argument, pArg, is an application data pointer that is passed 5002 ** through as the first argument to the collating function callback. 5003 ** 5004 ** ^The fifth argument, xCallback, is a pointer to the collating function. 5005 ** ^Multiple collating functions can be registered using the same name but 5006 ** with different eTextRep parameters and SQLite will use whichever 5007 ** function requires the least amount of data transformation. 5008 ** ^If the xCallback argument is NULL then the collating function is 5009 ** deleted. ^When all collating functions having the same name are deleted, 5010 ** that collation is no longer usable. 5011 ** 5012 ** ^The collating function callback is invoked with a copy of the pArg 5013 ** application data pointer and with two strings in the encoding specified 5014 ** by the eTextRep argument. The collating function must return an 5015 ** integer that is negative, zero, or positive 5016 ** if the first string is less than, equal to, or greater than the second, 5017 ** respectively. A collating function must always return the same answer 5018 ** given the same inputs. If two or more collating functions are registered 5019 ** to the same collation name (using different eTextRep values) then all 5020 ** must give an equivalent answer when invoked with equivalent strings. 5021 ** The collating function must obey the following properties for all 5022 ** strings A, B, and C: 5023 ** 5024 ** <ol> 5025 ** <li> If A==B then B==A. 5026 ** <li> If A==B and B==C then A==C. 5027 ** <li> If A<B THEN B>A. 5028 ** <li> If A<B and B<C then A<C. 5029 ** </ol> 5030 ** 5031 ** If a collating function fails any of the above constraints and that 5032 ** collating function is registered and used, then the behavior of SQLite 5033 ** is undefined. 5034 ** 5035 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5036 ** with the addition that the xDestroy callback is invoked on pArg when 5037 ** the collating function is deleted. 5038 ** ^Collating functions are deleted when they are overridden by later 5039 ** calls to the collation creation functions or when the 5040 ** [database connection] is closed using [sqlite3_close()]. 5041 ** 5042 ** ^The xDestroy callback is <u>not</u> called if the 5043 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5044 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5045 ** check the return code and dispose of the application data pointer 5046 ** themselves rather than expecting SQLite to deal with it for them. 5047 ** This is different from every other SQLite interface. The inconsistency 5048 ** is unfortunate but cannot be changed without breaking backwards 5049 ** compatibility. 5050 ** 5051 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5052 */ 5053 SQLITE_API int sqlite3_create_collation( 5054 sqlite3*, 5055 const char *zName, 5056 int eTextRep, 5057 void *pArg, 5058 int(*xCompare)(void*,int,const void*,int,const void*) 5059 ); 5060 SQLITE_API int sqlite3_create_collation_v2( 5061 sqlite3*, 5062 const char *zName, 5063 int eTextRep, 5064 void *pArg, 5065 int(*xCompare)(void*,int,const void*,int,const void*), 5066 void(*xDestroy)(void*) 5067 ); 5068 SQLITE_API int sqlite3_create_collation16( 5069 sqlite3*, 5070 const void *zName, 5071 int eTextRep, 5072 void *pArg, 5073 int(*xCompare)(void*,int,const void*,int,const void*) 5074 ); 5075 5076 /* 5077 ** CAPI3REF: Collation Needed Callbacks 5078 ** METHOD: sqlite3 5079 ** 5080 ** ^To avoid having to register all collation sequences before a database 5081 ** can be used, a single callback function may be registered with the 5082 ** [database connection] to be invoked whenever an undefined collation 5083 ** sequence is required. 5084 ** 5085 ** ^If the function is registered using the sqlite3_collation_needed() API, 5086 ** then it is passed the names of undefined collation sequences as strings 5087 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5088 ** the names are passed as UTF-16 in machine native byte order. 5089 ** ^A call to either function replaces the existing collation-needed callback. 5090 ** 5091 ** ^(When the callback is invoked, the first argument passed is a copy 5092 ** of the second argument to sqlite3_collation_needed() or 5093 ** sqlite3_collation_needed16(). The second argument is the database 5094 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5095 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5096 ** sequence function required. The fourth parameter is the name of the 5097 ** required collation sequence.)^ 5098 ** 5099 ** The callback function should register the desired collation using 5100 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5101 ** [sqlite3_create_collation_v2()]. 5102 */ 5103 SQLITE_API int sqlite3_collation_needed( 5104 sqlite3*, 5105 void*, 5106 void(*)(void*,sqlite3*,int eTextRep,const char*) 5107 ); 5108 SQLITE_API int sqlite3_collation_needed16( 5109 sqlite3*, 5110 void*, 5111 void(*)(void*,sqlite3*,int eTextRep,const void*) 5112 ); 5113 5114 #ifdef SQLITE_HAS_CODEC 5115 /* 5116 ** Specify the key for an encrypted database. This routine should be 5117 ** called right after sqlite3_open(). 5118 ** 5119 ** The code to implement this API is not available in the public release 5120 ** of SQLite. 5121 */ 5122 SQLITE_API int sqlite3_key( 5123 sqlite3 *db, /* Database to be rekeyed */ 5124 const void *pKey, int nKey /* The key */ 5125 ); 5126 SQLITE_API int sqlite3_key_v2( 5127 sqlite3 *db, /* Database to be rekeyed */ 5128 const char *zDbName, /* Name of the database */ 5129 const void *pKey, int nKey /* The key */ 5130 ); 5131 5132 /* 5133 ** Change the key on an open database. If the current database is not 5134 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5135 ** database is decrypted. 5136 ** 5137 ** The code to implement this API is not available in the public release 5138 ** of SQLite. 5139 */ 5140 SQLITE_API int sqlite3_rekey( 5141 sqlite3 *db, /* Database to be rekeyed */ 5142 const void *pKey, int nKey /* The new key */ 5143 ); 5144 SQLITE_API int sqlite3_rekey_v2( 5145 sqlite3 *db, /* Database to be rekeyed */ 5146 const char *zDbName, /* Name of the database */ 5147 const void *pKey, int nKey /* The new key */ 5148 ); 5149 5150 /* 5151 ** Specify the activation key for a SEE database. Unless 5152 ** activated, none of the SEE routines will work. 5153 */ 5154 SQLITE_API void sqlite3_activate_see( 5155 const char *zPassPhrase /* Activation phrase */ 5156 ); 5157 #endif 5158 5159 #ifdef SQLITE_ENABLE_CEROD 5160 /* 5161 ** Specify the activation key for a CEROD database. Unless 5162 ** activated, none of the CEROD routines will work. 5163 */ 5164 SQLITE_API void sqlite3_activate_cerod( 5165 const char *zPassPhrase /* Activation phrase */ 5166 ); 5167 #endif 5168 5169 /* 5170 ** CAPI3REF: Suspend Execution For A Short Time 5171 ** 5172 ** The sqlite3_sleep() function causes the current thread to suspend execution 5173 ** for at least a number of milliseconds specified in its parameter. 5174 ** 5175 ** If the operating system does not support sleep requests with 5176 ** millisecond time resolution, then the time will be rounded up to 5177 ** the nearest second. The number of milliseconds of sleep actually 5178 ** requested from the operating system is returned. 5179 ** 5180 ** ^SQLite implements this interface by calling the xSleep() 5181 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5182 ** of the default VFS is not implemented correctly, or not implemented at 5183 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5184 ** in the previous paragraphs. 5185 */ 5186 SQLITE_API int sqlite3_sleep(int); 5187 5188 /* 5189 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5190 ** 5191 ** ^(If this global variable is made to point to a string which is 5192 ** the name of a folder (a.k.a. directory), then all temporary files 5193 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5194 ** will be placed in that directory.)^ ^If this variable 5195 ** is a NULL pointer, then SQLite performs a search for an appropriate 5196 ** temporary file directory. 5197 ** 5198 ** Applications are strongly discouraged from using this global variable. 5199 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5200 ** But for all other platforms, it is highly recommended that applications 5201 ** neither read nor write this variable. This global variable is a relic 5202 ** that exists for backwards compatibility of legacy applications and should 5203 ** be avoided in new projects. 5204 ** 5205 ** It is not safe to read or modify this variable in more than one 5206 ** thread at a time. It is not safe to read or modify this variable 5207 ** if a [database connection] is being used at the same time in a separate 5208 ** thread. 5209 ** It is intended that this variable be set once 5210 ** as part of process initialization and before any SQLite interface 5211 ** routines have been called and that this variable remain unchanged 5212 ** thereafter. 5213 ** 5214 ** ^The [temp_store_directory pragma] may modify this variable and cause 5215 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5216 ** the [temp_store_directory pragma] always assumes that any string 5217 ** that this variable points to is held in memory obtained from 5218 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5219 ** using [sqlite3_free]. 5220 ** Hence, if this variable is modified directly, either it should be 5221 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5222 ** or else the use of the [temp_store_directory pragma] should be avoided. 5223 ** Except when requested by the [temp_store_directory pragma], SQLite 5224 ** does not free the memory that sqlite3_temp_directory points to. If 5225 ** the application wants that memory to be freed, it must do 5226 ** so itself, taking care to only do so after all [database connection] 5227 ** objects have been destroyed. 5228 ** 5229 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5230 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5231 ** features that require the use of temporary files may fail. Here is an 5232 ** example of how to do this using C++ with the Windows Runtime: 5233 ** 5234 ** <blockquote><pre> 5235 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5236 ** TemporaryFolder->Path->Data(); 5237 ** char zPathBuf[MAX_PATH + 1]; 5238 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5239 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5240 ** NULL, NULL); 5241 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5242 ** </pre></blockquote> 5243 */ 5244 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5245 5246 /* 5247 ** CAPI3REF: Name Of The Folder Holding Database Files 5248 ** 5249 ** ^(If this global variable is made to point to a string which is 5250 ** the name of a folder (a.k.a. directory), then all database files 5251 ** specified with a relative pathname and created or accessed by 5252 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5253 ** to be relative to that directory.)^ ^If this variable is a NULL 5254 ** pointer, then SQLite assumes that all database files specified 5255 ** with a relative pathname are relative to the current directory 5256 ** for the process. Only the windows VFS makes use of this global 5257 ** variable; it is ignored by the unix VFS. 5258 ** 5259 ** Changing the value of this variable while a database connection is 5260 ** open can result in a corrupt database. 5261 ** 5262 ** It is not safe to read or modify this variable in more than one 5263 ** thread at a time. It is not safe to read or modify this variable 5264 ** if a [database connection] is being used at the same time in a separate 5265 ** thread. 5266 ** It is intended that this variable be set once 5267 ** as part of process initialization and before any SQLite interface 5268 ** routines have been called and that this variable remain unchanged 5269 ** thereafter. 5270 ** 5271 ** ^The [data_store_directory pragma] may modify this variable and cause 5272 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5273 ** the [data_store_directory pragma] always assumes that any string 5274 ** that this variable points to is held in memory obtained from 5275 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5276 ** using [sqlite3_free]. 5277 ** Hence, if this variable is modified directly, either it should be 5278 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5279 ** or else the use of the [data_store_directory pragma] should be avoided. 5280 */ 5281 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5282 5283 /* 5284 ** CAPI3REF: Test For Auto-Commit Mode 5285 ** KEYWORDS: {autocommit mode} 5286 ** METHOD: sqlite3 5287 ** 5288 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5289 ** zero if the given database connection is or is not in autocommit mode, 5290 ** respectively. ^Autocommit mode is on by default. 5291 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5292 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5293 ** 5294 ** If certain kinds of errors occur on a statement within a multi-statement 5295 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5296 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5297 ** transaction might be rolled back automatically. The only way to 5298 ** find out whether SQLite automatically rolled back the transaction after 5299 ** an error is to use this function. 5300 ** 5301 ** If another thread changes the autocommit status of the database 5302 ** connection while this routine is running, then the return value 5303 ** is undefined. 5304 */ 5305 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5306 5307 /* 5308 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5309 ** METHOD: sqlite3_stmt 5310 ** 5311 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5312 ** to which a [prepared statement] belongs. ^The [database connection] 5313 ** returned by sqlite3_db_handle is the same [database connection] 5314 ** that was the first argument 5315 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5316 ** create the statement in the first place. 5317 */ 5318 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5319 5320 /* 5321 ** CAPI3REF: Return The Filename For A Database Connection 5322 ** METHOD: sqlite3 5323 ** 5324 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5325 ** associated with database N of connection D. ^The main database file 5326 ** has the name "main". If there is no attached database N on the database 5327 ** connection D, or if database N is a temporary or in-memory database, then 5328 ** a NULL pointer is returned. 5329 ** 5330 ** ^The filename returned by this function is the output of the 5331 ** xFullPathname method of the [VFS]. ^In other words, the filename 5332 ** will be an absolute pathname, even if the filename used 5333 ** to open the database originally was a URI or relative pathname. 5334 */ 5335 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5336 5337 /* 5338 ** CAPI3REF: Determine if a database is read-only 5339 ** METHOD: sqlite3 5340 ** 5341 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5342 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5343 ** the name of a database on connection D. 5344 */ 5345 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5346 5347 /* 5348 ** CAPI3REF: Find the next prepared statement 5349 ** METHOD: sqlite3 5350 ** 5351 ** ^This interface returns a pointer to the next [prepared statement] after 5352 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5353 ** then this interface returns a pointer to the first prepared statement 5354 ** associated with the database connection pDb. ^If no prepared statement 5355 ** satisfies the conditions of this routine, it returns NULL. 5356 ** 5357 ** The [database connection] pointer D in a call to 5358 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5359 ** connection and in particular must not be a NULL pointer. 5360 */ 5361 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5362 5363 /* 5364 ** CAPI3REF: Commit And Rollback Notification Callbacks 5365 ** METHOD: sqlite3 5366 ** 5367 ** ^The sqlite3_commit_hook() interface registers a callback 5368 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5369 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5370 ** for the same database connection is overridden. 5371 ** ^The sqlite3_rollback_hook() interface registers a callback 5372 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5373 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5374 ** for the same database connection is overridden. 5375 ** ^The pArg argument is passed through to the callback. 5376 ** ^If the callback on a commit hook function returns non-zero, 5377 ** then the commit is converted into a rollback. 5378 ** 5379 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5380 ** return the P argument from the previous call of the same function 5381 ** on the same [database connection] D, or NULL for 5382 ** the first call for each function on D. 5383 ** 5384 ** The commit and rollback hook callbacks are not reentrant. 5385 ** The callback implementation must not do anything that will modify 5386 ** the database connection that invoked the callback. Any actions 5387 ** to modify the database connection must be deferred until after the 5388 ** completion of the [sqlite3_step()] call that triggered the commit 5389 ** or rollback hook in the first place. 5390 ** Note that running any other SQL statements, including SELECT statements, 5391 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5392 ** the database connections for the meaning of "modify" in this paragraph. 5393 ** 5394 ** ^Registering a NULL function disables the callback. 5395 ** 5396 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5397 ** operation is allowed to continue normally. ^If the commit hook 5398 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5399 ** ^The rollback hook is invoked on a rollback that results from a commit 5400 ** hook returning non-zero, just as it would be with any other rollback. 5401 ** 5402 ** ^For the purposes of this API, a transaction is said to have been 5403 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5404 ** an error or constraint causes an implicit rollback to occur. 5405 ** ^The rollback callback is not invoked if a transaction is 5406 ** automatically rolled back because the database connection is closed. 5407 ** 5408 ** See also the [sqlite3_update_hook()] interface. 5409 */ 5410 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5411 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5412 5413 /* 5414 ** CAPI3REF: Data Change Notification Callbacks 5415 ** METHOD: sqlite3 5416 ** 5417 ** ^The sqlite3_update_hook() interface registers a callback function 5418 ** with the [database connection] identified by the first argument 5419 ** to be invoked whenever a row is updated, inserted or deleted in 5420 ** a [rowid table]. 5421 ** ^Any callback set by a previous call to this function 5422 ** for the same database connection is overridden. 5423 ** 5424 ** ^The second argument is a pointer to the function to invoke when a 5425 ** row is updated, inserted or deleted in a rowid table. 5426 ** ^The first argument to the callback is a copy of the third argument 5427 ** to sqlite3_update_hook(). 5428 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5429 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5430 ** to be invoked. 5431 ** ^The third and fourth arguments to the callback contain pointers to the 5432 ** database and table name containing the affected row. 5433 ** ^The final callback parameter is the [rowid] of the row. 5434 ** ^In the case of an update, this is the [rowid] after the update takes place. 5435 ** 5436 ** ^(The update hook is not invoked when internal system tables are 5437 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5438 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5439 ** 5440 ** ^In the current implementation, the update hook 5441 ** is not invoked when conflicting rows are deleted because of an 5442 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5443 ** invoked when rows are deleted using the [truncate optimization]. 5444 ** The exceptions defined in this paragraph might change in a future 5445 ** release of SQLite. 5446 ** 5447 ** The update hook implementation must not do anything that will modify 5448 ** the database connection that invoked the update hook. Any actions 5449 ** to modify the database connection must be deferred until after the 5450 ** completion of the [sqlite3_step()] call that triggered the update hook. 5451 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5452 ** database connections for the meaning of "modify" in this paragraph. 5453 ** 5454 ** ^The sqlite3_update_hook(D,C,P) function 5455 ** returns the P argument from the previous call 5456 ** on the same [database connection] D, or NULL for 5457 ** the first call on D. 5458 ** 5459 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5460 ** and [sqlite3_preupdate_hook()] interfaces. 5461 */ 5462 SQLITE_API void *sqlite3_update_hook( 5463 sqlite3*, 5464 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5465 void* 5466 ); 5467 5468 /* 5469 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5470 ** 5471 ** ^(This routine enables or disables the sharing of the database cache 5472 ** and schema data structures between [database connection | connections] 5473 ** to the same database. Sharing is enabled if the argument is true 5474 ** and disabled if the argument is false.)^ 5475 ** 5476 ** ^Cache sharing is enabled and disabled for an entire process. 5477 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5478 ** In prior versions of SQLite, 5479 ** sharing was enabled or disabled for each thread separately. 5480 ** 5481 ** ^(The cache sharing mode set by this interface effects all subsequent 5482 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5483 ** Existing database connections continue use the sharing mode 5484 ** that was in effect at the time they were opened.)^ 5485 ** 5486 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5487 ** successfully. An [error code] is returned otherwise.)^ 5488 ** 5489 ** ^Shared cache is disabled by default. But this might change in 5490 ** future releases of SQLite. Applications that care about shared 5491 ** cache setting should set it explicitly. 5492 ** 5493 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5494 ** and will always return SQLITE_MISUSE. On those systems, 5495 ** shared cache mode should be enabled per-database connection via 5496 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5497 ** 5498 ** This interface is threadsafe on processors where writing a 5499 ** 32-bit integer is atomic. 5500 ** 5501 ** See Also: [SQLite Shared-Cache Mode] 5502 */ 5503 SQLITE_API int sqlite3_enable_shared_cache(int); 5504 5505 /* 5506 ** CAPI3REF: Attempt To Free Heap Memory 5507 ** 5508 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5509 ** of heap memory by deallocating non-essential memory allocations 5510 ** held by the database library. Memory used to cache database 5511 ** pages to improve performance is an example of non-essential memory. 5512 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5513 ** which might be more or less than the amount requested. 5514 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5515 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5516 ** 5517 ** See also: [sqlite3_db_release_memory()] 5518 */ 5519 SQLITE_API int sqlite3_release_memory(int); 5520 5521 /* 5522 ** CAPI3REF: Free Memory Used By A Database Connection 5523 ** METHOD: sqlite3 5524 ** 5525 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5526 ** memory as possible from database connection D. Unlike the 5527 ** [sqlite3_release_memory()] interface, this interface is in effect even 5528 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5529 ** omitted. 5530 ** 5531 ** See also: [sqlite3_release_memory()] 5532 */ 5533 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5534 5535 /* 5536 ** CAPI3REF: Impose A Limit On Heap Size 5537 ** 5538 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5539 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5540 ** ^SQLite strives to keep heap memory utilization below the soft heap 5541 ** limit by reducing the number of pages held in the page cache 5542 ** as heap memory usages approaches the limit. 5543 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5544 ** below the limit, it will exceed the limit rather than generate 5545 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5546 ** is advisory only. 5547 ** 5548 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5549 ** the soft heap limit prior to the call, or negative in the case of an 5550 ** error. ^If the argument N is negative 5551 ** then no change is made to the soft heap limit. Hence, the current 5552 ** size of the soft heap limit can be determined by invoking 5553 ** sqlite3_soft_heap_limit64() with a negative argument. 5554 ** 5555 ** ^If the argument N is zero then the soft heap limit is disabled. 5556 ** 5557 ** ^(The soft heap limit is not enforced in the current implementation 5558 ** if one or more of following conditions are true: 5559 ** 5560 ** <ul> 5561 ** <li> The soft heap limit is set to zero. 5562 ** <li> Memory accounting is disabled using a combination of the 5563 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5564 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5565 ** <li> An alternative page cache implementation is specified using 5566 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5567 ** <li> The page cache allocates from its own memory pool supplied 5568 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5569 ** from the heap. 5570 ** </ul>)^ 5571 ** 5572 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5573 ** the soft heap limit is enforced 5574 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5575 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5576 ** the soft heap limit is enforced on every memory allocation. Without 5577 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5578 ** when memory is allocated by the page cache. Testing suggests that because 5579 ** the page cache is the predominate memory user in SQLite, most 5580 ** applications will achieve adequate soft heap limit enforcement without 5581 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5582 ** 5583 ** The circumstances under which SQLite will enforce the soft heap limit may 5584 ** changes in future releases of SQLite. 5585 */ 5586 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5587 5588 /* 5589 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5590 ** DEPRECATED 5591 ** 5592 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5593 ** interface. This routine is provided for historical compatibility 5594 ** only. All new applications should use the 5595 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5596 */ 5597 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5598 5599 5600 /* 5601 ** CAPI3REF: Extract Metadata About A Column Of A Table 5602 ** METHOD: sqlite3 5603 ** 5604 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5605 ** information about column C of table T in database D 5606 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5607 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5608 ** the final five arguments with appropriate values if the specified 5609 ** column exists. ^The sqlite3_table_column_metadata() interface returns 5610 ** SQLITE_ERROR and if the specified column does not exist. 5611 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5612 ** NULL pointer, then this routine simply checks for the existence of the 5613 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5614 ** does not. 5615 ** 5616 ** ^The column is identified by the second, third and fourth parameters to 5617 ** this function. ^(The second parameter is either the name of the database 5618 ** (i.e. "main", "temp", or an attached database) containing the specified 5619 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5620 ** for the table using the same algorithm used by the database engine to 5621 ** resolve unqualified table references. 5622 ** 5623 ** ^The third and fourth parameters to this function are the table and column 5624 ** name of the desired column, respectively. 5625 ** 5626 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5627 ** and subsequent parameters to this function. ^Any of these arguments may be 5628 ** NULL, in which case the corresponding element of metadata is omitted. 5629 ** 5630 ** ^(<blockquote> 5631 ** <table border="1"> 5632 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5633 ** 5634 ** <tr><td> 5th <td> const char* <td> Data type 5635 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5636 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5637 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5638 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5639 ** </table> 5640 ** </blockquote>)^ 5641 ** 5642 ** ^The memory pointed to by the character pointers returned for the 5643 ** declaration type and collation sequence is valid until the next 5644 ** call to any SQLite API function. 5645 ** 5646 ** ^If the specified table is actually a view, an [error code] is returned. 5647 ** 5648 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5649 ** is not a [WITHOUT ROWID] table and an 5650 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5651 ** parameters are set for the explicitly declared column. ^(If there is no 5652 ** [INTEGER PRIMARY KEY] column, then the outputs 5653 ** for the [rowid] are set as follows: 5654 ** 5655 ** <pre> 5656 ** data type: "INTEGER" 5657 ** collation sequence: "BINARY" 5658 ** not null: 0 5659 ** primary key: 1 5660 ** auto increment: 0 5661 ** </pre>)^ 5662 ** 5663 ** ^This function causes all database schemas to be read from disk and 5664 ** parsed, if that has not already been done, and returns an error if 5665 ** any errors are encountered while loading the schema. 5666 */ 5667 SQLITE_API int sqlite3_table_column_metadata( 5668 sqlite3 *db, /* Connection handle */ 5669 const char *zDbName, /* Database name or NULL */ 5670 const char *zTableName, /* Table name */ 5671 const char *zColumnName, /* Column name */ 5672 char const **pzDataType, /* OUTPUT: Declared data type */ 5673 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5674 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5675 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5676 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5677 ); 5678 5679 /* 5680 ** CAPI3REF: Load An Extension 5681 ** METHOD: sqlite3 5682 ** 5683 ** ^This interface loads an SQLite extension library from the named file. 5684 ** 5685 ** ^The sqlite3_load_extension() interface attempts to load an 5686 ** [SQLite extension] library contained in the file zFile. If 5687 ** the file cannot be loaded directly, attempts are made to load 5688 ** with various operating-system specific extensions added. 5689 ** So for example, if "samplelib" cannot be loaded, then names like 5690 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5691 ** be tried also. 5692 ** 5693 ** ^The entry point is zProc. 5694 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5695 ** entry point name on its own. It first tries "sqlite3_extension_init". 5696 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5697 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5698 ** characters in the filename from the last "/" to the first following 5699 ** "." and omitting any initial "lib".)^ 5700 ** ^The sqlite3_load_extension() interface returns 5701 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5702 ** ^If an error occurs and pzErrMsg is not 0, then the 5703 ** [sqlite3_load_extension()] interface shall attempt to 5704 ** fill *pzErrMsg with error message text stored in memory 5705 ** obtained from [sqlite3_malloc()]. The calling function 5706 ** should free this memory by calling [sqlite3_free()]. 5707 ** 5708 ** ^Extension loading must be enabled using 5709 ** [sqlite3_enable_load_extension()] or 5710 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5711 ** prior to calling this API, 5712 ** otherwise an error will be returned. 5713 ** 5714 ** <b>Security warning:</b> It is recommended that the 5715 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5716 ** interface. The use of the [sqlite3_enable_load_extension()] interface 5717 ** should be avoided. This will keep the SQL function [load_extension()] 5718 ** disabled and prevent SQL injections from giving attackers 5719 ** access to extension loading capabilities. 5720 ** 5721 ** See also the [load_extension() SQL function]. 5722 */ 5723 SQLITE_API int sqlite3_load_extension( 5724 sqlite3 *db, /* Load the extension into this database connection */ 5725 const char *zFile, /* Name of the shared library containing extension */ 5726 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5727 char **pzErrMsg /* Put error message here if not 0 */ 5728 ); 5729 5730 /* 5731 ** CAPI3REF: Enable Or Disable Extension Loading 5732 ** METHOD: sqlite3 5733 ** 5734 ** ^So as not to open security holes in older applications that are 5735 ** unprepared to deal with [extension loading], and as a means of disabling 5736 ** [extension loading] while evaluating user-entered SQL, the following API 5737 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5738 ** 5739 ** ^Extension loading is off by default. 5740 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5741 ** to turn extension loading on and call it with onoff==0 to turn 5742 ** it back off again. 5743 ** 5744 ** ^This interface enables or disables both the C-API 5745 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5746 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5747 ** to enable or disable only the C-API.)^ 5748 ** 5749 ** <b>Security warning:</b> It is recommended that extension loading 5750 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5751 ** rather than this interface, so the [load_extension()] SQL function 5752 ** remains disabled. This will prevent SQL injections from giving attackers 5753 ** access to extension loading capabilities. 5754 */ 5755 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5756 5757 /* 5758 ** CAPI3REF: Automatically Load Statically Linked Extensions 5759 ** 5760 ** ^This interface causes the xEntryPoint() function to be invoked for 5761 ** each new [database connection] that is created. The idea here is that 5762 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5763 ** that is to be automatically loaded into all new database connections. 5764 ** 5765 ** ^(Even though the function prototype shows that xEntryPoint() takes 5766 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5767 ** arguments and expects an integer result as if the signature of the 5768 ** entry point where as follows: 5769 ** 5770 ** <blockquote><pre> 5771 ** int xEntryPoint( 5772 ** sqlite3 *db, 5773 ** const char **pzErrMsg, 5774 ** const struct sqlite3_api_routines *pThunk 5775 ** ); 5776 ** </pre></blockquote>)^ 5777 ** 5778 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5779 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5780 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5781 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5782 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5783 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5784 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5785 ** 5786 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5787 ** on the list of automatic extensions is a harmless no-op. ^No entry point 5788 ** will be called more than once for each database connection that is opened. 5789 ** 5790 ** See also: [sqlite3_reset_auto_extension()] 5791 ** and [sqlite3_cancel_auto_extension()] 5792 */ 5793 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 5794 5795 /* 5796 ** CAPI3REF: Cancel Automatic Extension Loading 5797 ** 5798 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5799 ** initialization routine X that was registered using a prior call to 5800 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5801 ** routine returns 1 if initialization routine X was successfully 5802 ** unregistered and it returns 0 if X was not on the list of initialization 5803 ** routines. 5804 */ 5805 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 5806 5807 /* 5808 ** CAPI3REF: Reset Automatic Extension Loading 5809 ** 5810 ** ^This interface disables all automatic extensions previously 5811 ** registered using [sqlite3_auto_extension()]. 5812 */ 5813 SQLITE_API void sqlite3_reset_auto_extension(void); 5814 5815 /* 5816 ** The interface to the virtual-table mechanism is currently considered 5817 ** to be experimental. The interface might change in incompatible ways. 5818 ** If this is a problem for you, do not use the interface at this time. 5819 ** 5820 ** When the virtual-table mechanism stabilizes, we will declare the 5821 ** interface fixed, support it indefinitely, and remove this comment. 5822 */ 5823 5824 /* 5825 ** Structures used by the virtual table interface 5826 */ 5827 typedef struct sqlite3_vtab sqlite3_vtab; 5828 typedef struct sqlite3_index_info sqlite3_index_info; 5829 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5830 typedef struct sqlite3_module sqlite3_module; 5831 5832 /* 5833 ** CAPI3REF: Virtual Table Object 5834 ** KEYWORDS: sqlite3_module {virtual table module} 5835 ** 5836 ** This structure, sometimes called a "virtual table module", 5837 ** defines the implementation of a [virtual tables]. 5838 ** This structure consists mostly of methods for the module. 5839 ** 5840 ** ^A virtual table module is created by filling in a persistent 5841 ** instance of this structure and passing a pointer to that instance 5842 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5843 ** ^The registration remains valid until it is replaced by a different 5844 ** module or until the [database connection] closes. The content 5845 ** of this structure must not change while it is registered with 5846 ** any database connection. 5847 */ 5848 struct sqlite3_module { 5849 int iVersion; 5850 int (*xCreate)(sqlite3*, void *pAux, 5851 int argc, const char *const*argv, 5852 sqlite3_vtab **ppVTab, char**); 5853 int (*xConnect)(sqlite3*, void *pAux, 5854 int argc, const char *const*argv, 5855 sqlite3_vtab **ppVTab, char**); 5856 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5857 int (*xDisconnect)(sqlite3_vtab *pVTab); 5858 int (*xDestroy)(sqlite3_vtab *pVTab); 5859 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5860 int (*xClose)(sqlite3_vtab_cursor*); 5861 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5862 int argc, sqlite3_value **argv); 5863 int (*xNext)(sqlite3_vtab_cursor*); 5864 int (*xEof)(sqlite3_vtab_cursor*); 5865 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5866 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5867 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5868 int (*xBegin)(sqlite3_vtab *pVTab); 5869 int (*xSync)(sqlite3_vtab *pVTab); 5870 int (*xCommit)(sqlite3_vtab *pVTab); 5871 int (*xRollback)(sqlite3_vtab *pVTab); 5872 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5873 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5874 void **ppArg); 5875 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5876 /* The methods above are in version 1 of the sqlite_module object. Those 5877 ** below are for version 2 and greater. */ 5878 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5879 int (*xRelease)(sqlite3_vtab *pVTab, int); 5880 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5881 }; 5882 5883 /* 5884 ** CAPI3REF: Virtual Table Indexing Information 5885 ** KEYWORDS: sqlite3_index_info 5886 ** 5887 ** The sqlite3_index_info structure and its substructures is used as part 5888 ** of the [virtual table] interface to 5889 ** pass information into and receive the reply from the [xBestIndex] 5890 ** method of a [virtual table module]. The fields under **Inputs** are the 5891 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5892 ** results into the **Outputs** fields. 5893 ** 5894 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5895 ** 5896 ** <blockquote>column OP expr</blockquote> 5897 ** 5898 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5899 ** stored in aConstraint[].op using one of the 5900 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5901 ** ^(The index of the column is stored in 5902 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5903 ** expr on the right-hand side can be evaluated (and thus the constraint 5904 ** is usable) and false if it cannot.)^ 5905 ** 5906 ** ^The optimizer automatically inverts terms of the form "expr OP column" 5907 ** and makes other simplifications to the WHERE clause in an attempt to 5908 ** get as many WHERE clause terms into the form shown above as possible. 5909 ** ^The aConstraint[] array only reports WHERE clause terms that are 5910 ** relevant to the particular virtual table being queried. 5911 ** 5912 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5913 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5914 ** 5915 ** The colUsed field indicates which columns of the virtual table may be 5916 ** required by the current scan. Virtual table columns are numbered from 5917 ** zero in the order in which they appear within the CREATE TABLE statement 5918 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5919 ** the corresponding bit is set within the colUsed mask if the column may be 5920 ** required by SQLite. If the table has at least 64 columns and any column 5921 ** to the right of the first 63 is required, then bit 63 of colUsed is also 5922 ** set. In other words, column iCol may be required if the expression 5923 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5924 ** non-zero. 5925 ** 5926 ** The [xBestIndex] method must fill aConstraintUsage[] with information 5927 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5928 ** the right-hand side of the corresponding aConstraint[] is evaluated 5929 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5930 ** is true, then the constraint is assumed to be fully handled by the 5931 ** virtual table and is not checked again by SQLite.)^ 5932 ** 5933 ** ^The idxNum and idxPtr values are recorded and passed into the 5934 ** [xFilter] method. 5935 ** ^[sqlite3_free()] is used to free idxPtr if and only if 5936 ** needToFreeIdxPtr is true. 5937 ** 5938 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5939 ** the correct order to satisfy the ORDER BY clause so that no separate 5940 ** sorting step is required. 5941 ** 5942 ** ^The estimatedCost value is an estimate of the cost of a particular 5943 ** strategy. A cost of N indicates that the cost of the strategy is similar 5944 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 5945 ** indicates that the expense of the operation is similar to that of a 5946 ** binary search on a unique indexed field of an SQLite table with N rows. 5947 ** 5948 ** ^The estimatedRows value is an estimate of the number of rows that 5949 ** will be returned by the strategy. 5950 ** 5951 ** The xBestIndex method may optionally populate the idxFlags field with a 5952 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5953 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5954 ** assumes that the strategy may visit at most one row. 5955 ** 5956 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5957 ** SQLite also assumes that if a call to the xUpdate() method is made as 5958 ** part of the same statement to delete or update a virtual table row and the 5959 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5960 ** any database changes. In other words, if the xUpdate() returns 5961 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5962 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5963 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5964 ** the xUpdate method are automatically rolled back by SQLite. 5965 ** 5966 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5967 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 5968 ** If a virtual table extension is 5969 ** used with an SQLite version earlier than 3.8.2, the results of attempting 5970 ** to read or write the estimatedRows field are undefined (but are likely 5971 ** to included crashing the application). The estimatedRows field should 5972 ** therefore only be used if [sqlite3_libversion_number()] returns a 5973 ** value greater than or equal to 3008002. Similarly, the idxFlags field 5974 ** was added for [version 3.9.0] ([dateof:3.9.0]). 5975 ** It may therefore only be used if 5976 ** sqlite3_libversion_number() returns a value greater than or equal to 5977 ** 3009000. 5978 */ 5979 struct sqlite3_index_info { 5980 /* Inputs */ 5981 int nConstraint; /* Number of entries in aConstraint */ 5982 struct sqlite3_index_constraint { 5983 int iColumn; /* Column constrained. -1 for ROWID */ 5984 unsigned char op; /* Constraint operator */ 5985 unsigned char usable; /* True if this constraint is usable */ 5986 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5987 } *aConstraint; /* Table of WHERE clause constraints */ 5988 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5989 struct sqlite3_index_orderby { 5990 int iColumn; /* Column number */ 5991 unsigned char desc; /* True for DESC. False for ASC. */ 5992 } *aOrderBy; /* The ORDER BY clause */ 5993 /* Outputs */ 5994 struct sqlite3_index_constraint_usage { 5995 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5996 unsigned char omit; /* Do not code a test for this constraint */ 5997 } *aConstraintUsage; 5998 int idxNum; /* Number used to identify the index */ 5999 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6000 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6001 int orderByConsumed; /* True if output is already ordered */ 6002 double estimatedCost; /* Estimated cost of using this index */ 6003 /* Fields below are only available in SQLite 3.8.2 and later */ 6004 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6005 /* Fields below are only available in SQLite 3.9.0 and later */ 6006 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6007 /* Fields below are only available in SQLite 3.10.0 and later */ 6008 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6009 }; 6010 6011 /* 6012 ** CAPI3REF: Virtual Table Scan Flags 6013 */ 6014 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6015 6016 /* 6017 ** CAPI3REF: Virtual Table Constraint Operator Codes 6018 ** 6019 ** These macros defined the allowed values for the 6020 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6021 ** an operator that is part of a constraint term in the wHERE clause of 6022 ** a query that uses a [virtual table]. 6023 */ 6024 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6025 #define SQLITE_INDEX_CONSTRAINT_GT 4 6026 #define SQLITE_INDEX_CONSTRAINT_LE 8 6027 #define SQLITE_INDEX_CONSTRAINT_LT 16 6028 #define SQLITE_INDEX_CONSTRAINT_GE 32 6029 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6030 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6031 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6032 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6033 6034 /* 6035 ** CAPI3REF: Register A Virtual Table Implementation 6036 ** METHOD: sqlite3 6037 ** 6038 ** ^These routines are used to register a new [virtual table module] name. 6039 ** ^Module names must be registered before 6040 ** creating a new [virtual table] using the module and before using a 6041 ** preexisting [virtual table] for the module. 6042 ** 6043 ** ^The module name is registered on the [database connection] specified 6044 ** by the first parameter. ^The name of the module is given by the 6045 ** second parameter. ^The third parameter is a pointer to 6046 ** the implementation of the [virtual table module]. ^The fourth 6047 ** parameter is an arbitrary client data pointer that is passed through 6048 ** into the [xCreate] and [xConnect] methods of the virtual table module 6049 ** when a new virtual table is be being created or reinitialized. 6050 ** 6051 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6052 ** is a pointer to a destructor for the pClientData. ^SQLite will 6053 ** invoke the destructor function (if it is not NULL) when SQLite 6054 ** no longer needs the pClientData pointer. ^The destructor will also 6055 ** be invoked if the call to sqlite3_create_module_v2() fails. 6056 ** ^The sqlite3_create_module() 6057 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6058 ** destructor. 6059 */ 6060 SQLITE_API int sqlite3_create_module( 6061 sqlite3 *db, /* SQLite connection to register module with */ 6062 const char *zName, /* Name of the module */ 6063 const sqlite3_module *p, /* Methods for the module */ 6064 void *pClientData /* Client data for xCreate/xConnect */ 6065 ); 6066 SQLITE_API int sqlite3_create_module_v2( 6067 sqlite3 *db, /* SQLite connection to register module with */ 6068 const char *zName, /* Name of the module */ 6069 const sqlite3_module *p, /* Methods for the module */ 6070 void *pClientData, /* Client data for xCreate/xConnect */ 6071 void(*xDestroy)(void*) /* Module destructor function */ 6072 ); 6073 6074 /* 6075 ** CAPI3REF: Virtual Table Instance Object 6076 ** KEYWORDS: sqlite3_vtab 6077 ** 6078 ** Every [virtual table module] implementation uses a subclass 6079 ** of this object to describe a particular instance 6080 ** of the [virtual table]. Each subclass will 6081 ** be tailored to the specific needs of the module implementation. 6082 ** The purpose of this superclass is to define certain fields that are 6083 ** common to all module implementations. 6084 ** 6085 ** ^Virtual tables methods can set an error message by assigning a 6086 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6087 ** take care that any prior string is freed by a call to [sqlite3_free()] 6088 ** prior to assigning a new string to zErrMsg. ^After the error message 6089 ** is delivered up to the client application, the string will be automatically 6090 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6091 */ 6092 struct sqlite3_vtab { 6093 const sqlite3_module *pModule; /* The module for this virtual table */ 6094 int nRef; /* Number of open cursors */ 6095 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6096 /* Virtual table implementations will typically add additional fields */ 6097 }; 6098 6099 /* 6100 ** CAPI3REF: Virtual Table Cursor Object 6101 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6102 ** 6103 ** Every [virtual table module] implementation uses a subclass of the 6104 ** following structure to describe cursors that point into the 6105 ** [virtual table] and are used 6106 ** to loop through the virtual table. Cursors are created using the 6107 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6108 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6109 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6110 ** of the module. Each module implementation will define 6111 ** the content of a cursor structure to suit its own needs. 6112 ** 6113 ** This superclass exists in order to define fields of the cursor that 6114 ** are common to all implementations. 6115 */ 6116 struct sqlite3_vtab_cursor { 6117 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6118 /* Virtual table implementations will typically add additional fields */ 6119 }; 6120 6121 /* 6122 ** CAPI3REF: Declare The Schema Of A Virtual Table 6123 ** 6124 ** ^The [xCreate] and [xConnect] methods of a 6125 ** [virtual table module] call this interface 6126 ** to declare the format (the names and datatypes of the columns) of 6127 ** the virtual tables they implement. 6128 */ 6129 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6130 6131 /* 6132 ** CAPI3REF: Overload A Function For A Virtual Table 6133 ** METHOD: sqlite3 6134 ** 6135 ** ^(Virtual tables can provide alternative implementations of functions 6136 ** using the [xFindFunction] method of the [virtual table module]. 6137 ** But global versions of those functions 6138 ** must exist in order to be overloaded.)^ 6139 ** 6140 ** ^(This API makes sure a global version of a function with a particular 6141 ** name and number of parameters exists. If no such function exists 6142 ** before this API is called, a new function is created.)^ ^The implementation 6143 ** of the new function always causes an exception to be thrown. So 6144 ** the new function is not good for anything by itself. Its only 6145 ** purpose is to be a placeholder function that can be overloaded 6146 ** by a [virtual table]. 6147 */ 6148 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6149 6150 /* 6151 ** The interface to the virtual-table mechanism defined above (back up 6152 ** to a comment remarkably similar to this one) is currently considered 6153 ** to be experimental. The interface might change in incompatible ways. 6154 ** If this is a problem for you, do not use the interface at this time. 6155 ** 6156 ** When the virtual-table mechanism stabilizes, we will declare the 6157 ** interface fixed, support it indefinitely, and remove this comment. 6158 */ 6159 6160 /* 6161 ** CAPI3REF: A Handle To An Open BLOB 6162 ** KEYWORDS: {BLOB handle} {BLOB handles} 6163 ** 6164 ** An instance of this object represents an open BLOB on which 6165 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6166 ** ^Objects of this type are created by [sqlite3_blob_open()] 6167 ** and destroyed by [sqlite3_blob_close()]. 6168 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6169 ** can be used to read or write small subsections of the BLOB. 6170 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6171 */ 6172 typedef struct sqlite3_blob sqlite3_blob; 6173 6174 /* 6175 ** CAPI3REF: Open A BLOB For Incremental I/O 6176 ** METHOD: sqlite3 6177 ** CONSTRUCTOR: sqlite3_blob 6178 ** 6179 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6180 ** in row iRow, column zColumn, table zTable in database zDb; 6181 ** in other words, the same BLOB that would be selected by: 6182 ** 6183 ** <pre> 6184 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6185 ** </pre>)^ 6186 ** 6187 ** ^(Parameter zDb is not the filename that contains the database, but 6188 ** rather the symbolic name of the database. For attached databases, this is 6189 ** the name that appears after the AS keyword in the [ATTACH] statement. 6190 ** For the main database file, the database name is "main". For TEMP 6191 ** tables, the database name is "temp".)^ 6192 ** 6193 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6194 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6195 ** read-only access. 6196 ** 6197 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6198 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6199 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6200 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6201 ** on *ppBlob after this function it returns. 6202 ** 6203 ** This function fails with SQLITE_ERROR if any of the following are true: 6204 ** <ul> 6205 ** <li> ^(Database zDb does not exist)^, 6206 ** <li> ^(Table zTable does not exist within database zDb)^, 6207 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6208 ** <li> ^(Column zColumn does not exist)^, 6209 ** <li> ^(Row iRow is not present in the table)^, 6210 ** <li> ^(The specified column of row iRow contains a value that is not 6211 ** a TEXT or BLOB value)^, 6212 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6213 ** constraint and the blob is being opened for read/write access)^, 6214 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6215 ** column zColumn is part of a [child key] definition and the blob is 6216 ** being opened for read/write access)^. 6217 ** </ul> 6218 ** 6219 ** ^Unless it returns SQLITE_MISUSE, this function sets the 6220 ** [database connection] error code and message accessible via 6221 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6222 ** 6223 ** A BLOB referenced by sqlite3_blob_open() may be read using the 6224 ** [sqlite3_blob_read()] interface and modified by using 6225 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6226 ** different row of the same table using the [sqlite3_blob_reopen()] 6227 ** interface. However, the column, table, or database of a [BLOB handle] 6228 ** cannot be changed after the [BLOB handle] is opened. 6229 ** 6230 ** ^(If the row that a BLOB handle points to is modified by an 6231 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6232 ** then the BLOB handle is marked as "expired". 6233 ** This is true if any column of the row is changed, even a column 6234 ** other than the one the BLOB handle is open on.)^ 6235 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6236 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6237 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6238 ** rolled back by the expiration of the BLOB. Such changes will eventually 6239 ** commit if the transaction continues to completion.)^ 6240 ** 6241 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6242 ** the opened blob. ^The size of a blob may not be changed by this 6243 ** interface. Use the [UPDATE] SQL command to change the size of a 6244 ** blob. 6245 ** 6246 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6247 ** and the built-in [zeroblob] SQL function may be used to create a 6248 ** zero-filled blob to read or write using the incremental-blob interface. 6249 ** 6250 ** To avoid a resource leak, every open [BLOB handle] should eventually 6251 ** be released by a call to [sqlite3_blob_close()]. 6252 ** 6253 ** See also: [sqlite3_blob_close()], 6254 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6255 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6256 */ 6257 SQLITE_API int sqlite3_blob_open( 6258 sqlite3*, 6259 const char *zDb, 6260 const char *zTable, 6261 const char *zColumn, 6262 sqlite3_int64 iRow, 6263 int flags, 6264 sqlite3_blob **ppBlob 6265 ); 6266 6267 /* 6268 ** CAPI3REF: Move a BLOB Handle to a New Row 6269 ** METHOD: sqlite3_blob 6270 ** 6271 ** ^This function is used to move an existing [BLOB handle] so that it points 6272 ** to a different row of the same database table. ^The new row is identified 6273 ** by the rowid value passed as the second argument. Only the row can be 6274 ** changed. ^The database, table and column on which the blob handle is open 6275 ** remain the same. Moving an existing [BLOB handle] to a new row is 6276 ** faster than closing the existing handle and opening a new one. 6277 ** 6278 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6279 ** it must exist and there must be either a blob or text value stored in 6280 ** the nominated column.)^ ^If the new row is not present in the table, or if 6281 ** it does not contain a blob or text value, or if another error occurs, an 6282 ** SQLite error code is returned and the blob handle is considered aborted. 6283 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6284 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6285 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6286 ** always returns zero. 6287 ** 6288 ** ^This function sets the database handle error code and message. 6289 */ 6290 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6291 6292 /* 6293 ** CAPI3REF: Close A BLOB Handle 6294 ** DESTRUCTOR: sqlite3_blob 6295 ** 6296 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6297 ** unconditionally. Even if this routine returns an error code, the 6298 ** handle is still closed.)^ 6299 ** 6300 ** ^If the blob handle being closed was opened for read-write access, and if 6301 ** the database is in auto-commit mode and there are no other open read-write 6302 ** blob handles or active write statements, the current transaction is 6303 ** committed. ^If an error occurs while committing the transaction, an error 6304 ** code is returned and the transaction rolled back. 6305 ** 6306 ** Calling this function with an argument that is not a NULL pointer or an 6307 ** open blob handle results in undefined behaviour. ^Calling this routine 6308 ** with a null pointer (such as would be returned by a failed call to 6309 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6310 ** is passed a valid open blob handle, the values returned by the 6311 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6312 */ 6313 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6314 6315 /* 6316 ** CAPI3REF: Return The Size Of An Open BLOB 6317 ** METHOD: sqlite3_blob 6318 ** 6319 ** ^Returns the size in bytes of the BLOB accessible via the 6320 ** successfully opened [BLOB handle] in its only argument. ^The 6321 ** incremental blob I/O routines can only read or overwriting existing 6322 ** blob content; they cannot change the size of a blob. 6323 ** 6324 ** This routine only works on a [BLOB handle] which has been created 6325 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6326 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6327 ** to this routine results in undefined and probably undesirable behavior. 6328 */ 6329 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6330 6331 /* 6332 ** CAPI3REF: Read Data From A BLOB Incrementally 6333 ** METHOD: sqlite3_blob 6334 ** 6335 ** ^(This function is used to read data from an open [BLOB handle] into a 6336 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6337 ** from the open BLOB, starting at offset iOffset.)^ 6338 ** 6339 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6340 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6341 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6342 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6343 ** can be determined using the [sqlite3_blob_bytes()] interface. 6344 ** 6345 ** ^An attempt to read from an expired [BLOB handle] fails with an 6346 ** error code of [SQLITE_ABORT]. 6347 ** 6348 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6349 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6350 ** 6351 ** This routine only works on a [BLOB handle] which has been created 6352 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6353 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6354 ** to this routine results in undefined and probably undesirable behavior. 6355 ** 6356 ** See also: [sqlite3_blob_write()]. 6357 */ 6358 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6359 6360 /* 6361 ** CAPI3REF: Write Data Into A BLOB Incrementally 6362 ** METHOD: sqlite3_blob 6363 ** 6364 ** ^(This function is used to write data into an open [BLOB handle] from a 6365 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6366 ** into the open BLOB, starting at offset iOffset.)^ 6367 ** 6368 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6369 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6370 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6371 ** [database connection] error code and message accessible via 6372 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6373 ** 6374 ** ^If the [BLOB handle] passed as the first argument was not opened for 6375 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6376 ** this function returns [SQLITE_READONLY]. 6377 ** 6378 ** This function may only modify the contents of the BLOB; it is 6379 ** not possible to increase the size of a BLOB using this API. 6380 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6381 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6382 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6383 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6384 ** than zero [SQLITE_ERROR] is returned and no data is written. 6385 ** 6386 ** ^An attempt to write to an expired [BLOB handle] fails with an 6387 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6388 ** before the [BLOB handle] expired are not rolled back by the 6389 ** expiration of the handle, though of course those changes might 6390 ** have been overwritten by the statement that expired the BLOB handle 6391 ** or by other independent statements. 6392 ** 6393 ** This routine only works on a [BLOB handle] which has been created 6394 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6395 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6396 ** to this routine results in undefined and probably undesirable behavior. 6397 ** 6398 ** See also: [sqlite3_blob_read()]. 6399 */ 6400 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6401 6402 /* 6403 ** CAPI3REF: Virtual File System Objects 6404 ** 6405 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6406 ** that SQLite uses to interact 6407 ** with the underlying operating system. Most SQLite builds come with a 6408 ** single default VFS that is appropriate for the host computer. 6409 ** New VFSes can be registered and existing VFSes can be unregistered. 6410 ** The following interfaces are provided. 6411 ** 6412 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6413 ** ^Names are case sensitive. 6414 ** ^Names are zero-terminated UTF-8 strings. 6415 ** ^If there is no match, a NULL pointer is returned. 6416 ** ^If zVfsName is NULL then the default VFS is returned. 6417 ** 6418 ** ^New VFSes are registered with sqlite3_vfs_register(). 6419 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6420 ** ^The same VFS can be registered multiple times without injury. 6421 ** ^To make an existing VFS into the default VFS, register it again 6422 ** with the makeDflt flag set. If two different VFSes with the 6423 ** same name are registered, the behavior is undefined. If a 6424 ** VFS is registered with a name that is NULL or an empty string, 6425 ** then the behavior is undefined. 6426 ** 6427 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6428 ** ^(If the default VFS is unregistered, another VFS is chosen as 6429 ** the default. The choice for the new VFS is arbitrary.)^ 6430 */ 6431 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6432 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6433 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6434 6435 /* 6436 ** CAPI3REF: Mutexes 6437 ** 6438 ** The SQLite core uses these routines for thread 6439 ** synchronization. Though they are intended for internal 6440 ** use by SQLite, code that links against SQLite is 6441 ** permitted to use any of these routines. 6442 ** 6443 ** The SQLite source code contains multiple implementations 6444 ** of these mutex routines. An appropriate implementation 6445 ** is selected automatically at compile-time. The following 6446 ** implementations are available in the SQLite core: 6447 ** 6448 ** <ul> 6449 ** <li> SQLITE_MUTEX_PTHREADS 6450 ** <li> SQLITE_MUTEX_W32 6451 ** <li> SQLITE_MUTEX_NOOP 6452 ** </ul> 6453 ** 6454 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6455 ** that does no real locking and is appropriate for use in 6456 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6457 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6458 ** and Windows. 6459 ** 6460 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6461 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6462 ** implementation is included with the library. In this case the 6463 ** application must supply a custom mutex implementation using the 6464 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6465 ** before calling sqlite3_initialize() or any other public sqlite3_ 6466 ** function that calls sqlite3_initialize(). 6467 ** 6468 ** ^The sqlite3_mutex_alloc() routine allocates a new 6469 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6470 ** routine returns NULL if it is unable to allocate the requested 6471 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6472 ** integer constants: 6473 ** 6474 ** <ul> 6475 ** <li> SQLITE_MUTEX_FAST 6476 ** <li> SQLITE_MUTEX_RECURSIVE 6477 ** <li> SQLITE_MUTEX_STATIC_MASTER 6478 ** <li> SQLITE_MUTEX_STATIC_MEM 6479 ** <li> SQLITE_MUTEX_STATIC_OPEN 6480 ** <li> SQLITE_MUTEX_STATIC_PRNG 6481 ** <li> SQLITE_MUTEX_STATIC_LRU 6482 ** <li> SQLITE_MUTEX_STATIC_PMEM 6483 ** <li> SQLITE_MUTEX_STATIC_APP1 6484 ** <li> SQLITE_MUTEX_STATIC_APP2 6485 ** <li> SQLITE_MUTEX_STATIC_APP3 6486 ** <li> SQLITE_MUTEX_STATIC_VFS1 6487 ** <li> SQLITE_MUTEX_STATIC_VFS2 6488 ** <li> SQLITE_MUTEX_STATIC_VFS3 6489 ** </ul> 6490 ** 6491 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6492 ** cause sqlite3_mutex_alloc() to create 6493 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6494 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6495 ** The mutex implementation does not need to make a distinction 6496 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6497 ** not want to. SQLite will only request a recursive mutex in 6498 ** cases where it really needs one. If a faster non-recursive mutex 6499 ** implementation is available on the host platform, the mutex subsystem 6500 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6501 ** 6502 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6503 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6504 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6505 ** used by the current version of SQLite. Future versions of SQLite 6506 ** may add additional static mutexes. Static mutexes are for internal 6507 ** use by SQLite only. Applications that use SQLite mutexes should 6508 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6509 ** SQLITE_MUTEX_RECURSIVE. 6510 ** 6511 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6512 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6513 ** returns a different mutex on every call. ^For the static 6514 ** mutex types, the same mutex is returned on every call that has 6515 ** the same type number. 6516 ** 6517 ** ^The sqlite3_mutex_free() routine deallocates a previously 6518 ** allocated dynamic mutex. Attempting to deallocate a static 6519 ** mutex results in undefined behavior. 6520 ** 6521 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6522 ** to enter a mutex. ^If another thread is already within the mutex, 6523 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6524 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6525 ** upon successful entry. ^(Mutexes created using 6526 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6527 ** In such cases, the 6528 ** mutex must be exited an equal number of times before another thread 6529 ** can enter.)^ If the same thread tries to enter any mutex other 6530 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6531 ** 6532 ** ^(Some systems (for example, Windows 95) do not support the operation 6533 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6534 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6535 ** sqlite3_mutex_try() as an optimization so this is acceptable 6536 ** behavior.)^ 6537 ** 6538 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6539 ** previously entered by the same thread. The behavior 6540 ** is undefined if the mutex is not currently entered by the 6541 ** calling thread or is not currently allocated. 6542 ** 6543 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6544 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6545 ** behave as no-ops. 6546 ** 6547 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6548 */ 6549 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 6550 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 6551 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 6552 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 6553 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 6554 6555 /* 6556 ** CAPI3REF: Mutex Methods Object 6557 ** 6558 ** An instance of this structure defines the low-level routines 6559 ** used to allocate and use mutexes. 6560 ** 6561 ** Usually, the default mutex implementations provided by SQLite are 6562 ** sufficient, however the application has the option of substituting a custom 6563 ** implementation for specialized deployments or systems for which SQLite 6564 ** does not provide a suitable implementation. In this case, the application 6565 ** creates and populates an instance of this structure to pass 6566 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6567 ** Additionally, an instance of this structure can be used as an 6568 ** output variable when querying the system for the current mutex 6569 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6570 ** 6571 ** ^The xMutexInit method defined by this structure is invoked as 6572 ** part of system initialization by the sqlite3_initialize() function. 6573 ** ^The xMutexInit routine is called by SQLite exactly once for each 6574 ** effective call to [sqlite3_initialize()]. 6575 ** 6576 ** ^The xMutexEnd method defined by this structure is invoked as 6577 ** part of system shutdown by the sqlite3_shutdown() function. The 6578 ** implementation of this method is expected to release all outstanding 6579 ** resources obtained by the mutex methods implementation, especially 6580 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6581 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6582 ** 6583 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6584 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6585 ** xMutexNotheld) implement the following interfaces (respectively): 6586 ** 6587 ** <ul> 6588 ** <li> [sqlite3_mutex_alloc()] </li> 6589 ** <li> [sqlite3_mutex_free()] </li> 6590 ** <li> [sqlite3_mutex_enter()] </li> 6591 ** <li> [sqlite3_mutex_try()] </li> 6592 ** <li> [sqlite3_mutex_leave()] </li> 6593 ** <li> [sqlite3_mutex_held()] </li> 6594 ** <li> [sqlite3_mutex_notheld()] </li> 6595 ** </ul>)^ 6596 ** 6597 ** The only difference is that the public sqlite3_XXX functions enumerated 6598 ** above silently ignore any invocations that pass a NULL pointer instead 6599 ** of a valid mutex handle. The implementations of the methods defined 6600 ** by this structure are not required to handle this case, the results 6601 ** of passing a NULL pointer instead of a valid mutex handle are undefined 6602 ** (i.e. it is acceptable to provide an implementation that segfaults if 6603 ** it is passed a NULL pointer). 6604 ** 6605 ** The xMutexInit() method must be threadsafe. It must be harmless to 6606 ** invoke xMutexInit() multiple times within the same process and without 6607 ** intervening calls to xMutexEnd(). Second and subsequent calls to 6608 ** xMutexInit() must be no-ops. 6609 ** 6610 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6611 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6612 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6613 ** memory allocation for a fast or recursive mutex. 6614 ** 6615 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6616 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6617 ** If xMutexInit fails in any way, it is expected to clean up after itself 6618 ** prior to returning. 6619 */ 6620 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6621 struct sqlite3_mutex_methods { 6622 int (*xMutexInit)(void); 6623 int (*xMutexEnd)(void); 6624 sqlite3_mutex *(*xMutexAlloc)(int); 6625 void (*xMutexFree)(sqlite3_mutex *); 6626 void (*xMutexEnter)(sqlite3_mutex *); 6627 int (*xMutexTry)(sqlite3_mutex *); 6628 void (*xMutexLeave)(sqlite3_mutex *); 6629 int (*xMutexHeld)(sqlite3_mutex *); 6630 int (*xMutexNotheld)(sqlite3_mutex *); 6631 }; 6632 6633 /* 6634 ** CAPI3REF: Mutex Verification Routines 6635 ** 6636 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6637 ** are intended for use inside assert() statements. The SQLite core 6638 ** never uses these routines except inside an assert() and applications 6639 ** are advised to follow the lead of the core. The SQLite core only 6640 ** provides implementations for these routines when it is compiled 6641 ** with the SQLITE_DEBUG flag. External mutex implementations 6642 ** are only required to provide these routines if SQLITE_DEBUG is 6643 ** defined and if NDEBUG is not defined. 6644 ** 6645 ** These routines should return true if the mutex in their argument 6646 ** is held or not held, respectively, by the calling thread. 6647 ** 6648 ** The implementation is not required to provide versions of these 6649 ** routines that actually work. If the implementation does not provide working 6650 ** versions of these routines, it should at least provide stubs that always 6651 ** return true so that one does not get spurious assertion failures. 6652 ** 6653 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6654 ** the routine should return 1. This seems counter-intuitive since 6655 ** clearly the mutex cannot be held if it does not exist. But 6656 ** the reason the mutex does not exist is because the build is not 6657 ** using mutexes. And we do not want the assert() containing the 6658 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6659 ** the appropriate thing to do. The sqlite3_mutex_notheld() 6660 ** interface should also return 1 when given a NULL pointer. 6661 */ 6662 #ifndef NDEBUG 6663 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 6664 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 6665 #endif 6666 6667 /* 6668 ** CAPI3REF: Mutex Types 6669 ** 6670 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6671 ** which is one of these integer constants. 6672 ** 6673 ** The set of static mutexes may change from one SQLite release to the 6674 ** next. Applications that override the built-in mutex logic must be 6675 ** prepared to accommodate additional static mutexes. 6676 */ 6677 #define SQLITE_MUTEX_FAST 0 6678 #define SQLITE_MUTEX_RECURSIVE 1 6679 #define SQLITE_MUTEX_STATIC_MASTER 2 6680 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6681 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6682 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6683 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 6684 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6685 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6686 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6687 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6688 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6689 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6690 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6691 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6692 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6693 6694 /* 6695 ** CAPI3REF: Retrieve the mutex for a database connection 6696 ** METHOD: sqlite3 6697 ** 6698 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6699 ** serializes access to the [database connection] given in the argument 6700 ** when the [threading mode] is Serialized. 6701 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6702 ** routine returns a NULL pointer. 6703 */ 6704 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6705 6706 /* 6707 ** CAPI3REF: Low-Level Control Of Database Files 6708 ** METHOD: sqlite3 6709 ** 6710 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6711 ** xFileControl method for the [sqlite3_io_methods] object associated 6712 ** with a particular database identified by the second argument. ^The 6713 ** name of the database is "main" for the main database or "temp" for the 6714 ** TEMP database, or the name that appears after the AS keyword for 6715 ** databases that are added using the [ATTACH] SQL command. 6716 ** ^A NULL pointer can be used in place of "main" to refer to the 6717 ** main database file. 6718 ** ^The third and fourth parameters to this routine 6719 ** are passed directly through to the second and third parameters of 6720 ** the xFileControl method. ^The return value of the xFileControl 6721 ** method becomes the return value of this routine. 6722 ** 6723 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6724 ** a pointer to the underlying [sqlite3_file] object to be written into 6725 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6726 ** case is a short-circuit path which does not actually invoke the 6727 ** underlying sqlite3_io_methods.xFileControl method. 6728 ** 6729 ** ^If the second parameter (zDbName) does not match the name of any 6730 ** open database file, then SQLITE_ERROR is returned. ^This error 6731 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6732 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6733 ** also return SQLITE_ERROR. There is no way to distinguish between 6734 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6735 ** xFileControl method. 6736 ** 6737 ** See also: [SQLITE_FCNTL_LOCKSTATE] 6738 */ 6739 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6740 6741 /* 6742 ** CAPI3REF: Testing Interface 6743 ** 6744 ** ^The sqlite3_test_control() interface is used to read out internal 6745 ** state of SQLite and to inject faults into SQLite for testing 6746 ** purposes. ^The first parameter is an operation code that determines 6747 ** the number, meaning, and operation of all subsequent parameters. 6748 ** 6749 ** This interface is not for use by applications. It exists solely 6750 ** for verifying the correct operation of the SQLite library. Depending 6751 ** on how the SQLite library is compiled, this interface might not exist. 6752 ** 6753 ** The details of the operation codes, their meanings, the parameters 6754 ** they take, and what they do are all subject to change without notice. 6755 ** Unlike most of the SQLite API, this function is not guaranteed to 6756 ** operate consistently from one release to the next. 6757 */ 6758 SQLITE_API int sqlite3_test_control(int op, ...); 6759 6760 /* 6761 ** CAPI3REF: Testing Interface Operation Codes 6762 ** 6763 ** These constants are the valid operation code parameters used 6764 ** as the first argument to [sqlite3_test_control()]. 6765 ** 6766 ** These parameters and their meanings are subject to change 6767 ** without notice. These values are for testing purposes only. 6768 ** Applications should not use any of these parameters or the 6769 ** [sqlite3_test_control()] interface. 6770 */ 6771 #define SQLITE_TESTCTRL_FIRST 5 6772 #define SQLITE_TESTCTRL_PRNG_SAVE 5 6773 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6774 #define SQLITE_TESTCTRL_PRNG_RESET 7 6775 #define SQLITE_TESTCTRL_BITVEC_TEST 8 6776 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6777 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6778 #define SQLITE_TESTCTRL_PENDING_BYTE 11 6779 #define SQLITE_TESTCTRL_ASSERT 12 6780 #define SQLITE_TESTCTRL_ALWAYS 13 6781 #define SQLITE_TESTCTRL_RESERVE 14 6782 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6783 #define SQLITE_TESTCTRL_ISKEYWORD 16 6784 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6785 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6786 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6787 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 6788 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6789 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6790 #define SQLITE_TESTCTRL_BYTEORDER 22 6791 #define SQLITE_TESTCTRL_ISINIT 23 6792 #define SQLITE_TESTCTRL_SORTER_MMAP 24 6793 #define SQLITE_TESTCTRL_IMPOSTER 25 6794 #define SQLITE_TESTCTRL_LAST 25 6795 6796 /* 6797 ** CAPI3REF: SQLite Runtime Status 6798 ** 6799 ** ^These interfaces are used to retrieve runtime status information 6800 ** about the performance of SQLite, and optionally to reset various 6801 ** highwater marks. ^The first argument is an integer code for 6802 ** the specific parameter to measure. ^(Recognized integer codes 6803 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 6804 ** ^The current value of the parameter is returned into *pCurrent. 6805 ** ^The highest recorded value is returned in *pHighwater. ^If the 6806 ** resetFlag is true, then the highest record value is reset after 6807 ** *pHighwater is written. ^(Some parameters do not record the highest 6808 ** value. For those parameters 6809 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6810 ** ^(Other parameters record only the highwater mark and not the current 6811 ** value. For these latter parameters nothing is written into *pCurrent.)^ 6812 ** 6813 ** ^The sqlite3_status() and sqlite3_status64() routines return 6814 ** SQLITE_OK on success and a non-zero [error code] on failure. 6815 ** 6816 ** If either the current value or the highwater mark is too large to 6817 ** be represented by a 32-bit integer, then the values returned by 6818 ** sqlite3_status() are undefined. 6819 ** 6820 ** See also: [sqlite3_db_status()] 6821 */ 6822 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6823 SQLITE_API int sqlite3_status64( 6824 int op, 6825 sqlite3_int64 *pCurrent, 6826 sqlite3_int64 *pHighwater, 6827 int resetFlag 6828 ); 6829 6830 6831 /* 6832 ** CAPI3REF: Status Parameters 6833 ** KEYWORDS: {status parameters} 6834 ** 6835 ** These integer constants designate various run-time status parameters 6836 ** that can be returned by [sqlite3_status()]. 6837 ** 6838 ** <dl> 6839 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6840 ** <dd>This parameter is the current amount of memory checked out 6841 ** using [sqlite3_malloc()], either directly or indirectly. The 6842 ** figure includes calls made to [sqlite3_malloc()] by the application 6843 ** and internal memory usage by the SQLite library. Scratch memory 6844 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6845 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6846 ** this parameter. The amount returned is the sum of the allocation 6847 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6848 ** 6849 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6850 ** <dd>This parameter records the largest memory allocation request 6851 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6852 ** internal equivalents). Only the value returned in the 6853 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6854 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6855 ** 6856 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6857 ** <dd>This parameter records the number of separate memory allocations 6858 ** currently checked out.</dd>)^ 6859 ** 6860 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6861 ** <dd>This parameter returns the number of pages used out of the 6862 ** [pagecache memory allocator] that was configured using 6863 ** [SQLITE_CONFIG_PAGECACHE]. The 6864 ** value returned is in pages, not in bytes.</dd>)^ 6865 ** 6866 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6867 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6868 ** <dd>This parameter returns the number of bytes of page cache 6869 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6870 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6871 ** returned value includes allocations that overflowed because they 6872 ** where too large (they were larger than the "sz" parameter to 6873 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6874 ** no space was left in the page cache.</dd>)^ 6875 ** 6876 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6877 ** <dd>This parameter records the largest memory allocation request 6878 ** handed to [pagecache memory allocator]. Only the value returned in the 6879 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6880 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6881 ** 6882 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6883 ** <dd>This parameter returns the number of allocations used out of the 6884 ** [scratch memory allocator] configured using 6885 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6886 ** in bytes. Since a single thread may only have one scratch allocation 6887 ** outstanding at time, this parameter also reports the number of threads 6888 ** using scratch memory at the same time.</dd>)^ 6889 ** 6890 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6891 ** <dd>This parameter returns the number of bytes of scratch memory 6892 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6893 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6894 ** returned include overflows because the requested allocation was too 6895 ** larger (that is, because the requested allocation was larger than the 6896 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6897 ** slots were available. 6898 ** </dd>)^ 6899 ** 6900 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6901 ** <dd>This parameter records the largest memory allocation request 6902 ** handed to [scratch memory allocator]. Only the value returned in the 6903 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6904 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6905 ** 6906 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6907 ** <dd>The *pHighwater parameter records the deepest parser stack. 6908 ** The *pCurrent value is undefined. The *pHighwater value is only 6909 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6910 ** </dl> 6911 ** 6912 ** New status parameters may be added from time to time. 6913 */ 6914 #define SQLITE_STATUS_MEMORY_USED 0 6915 #define SQLITE_STATUS_PAGECACHE_USED 1 6916 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6917 #define SQLITE_STATUS_SCRATCH_USED 3 6918 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6919 #define SQLITE_STATUS_MALLOC_SIZE 5 6920 #define SQLITE_STATUS_PARSER_STACK 6 6921 #define SQLITE_STATUS_PAGECACHE_SIZE 7 6922 #define SQLITE_STATUS_SCRATCH_SIZE 8 6923 #define SQLITE_STATUS_MALLOC_COUNT 9 6924 6925 /* 6926 ** CAPI3REF: Database Connection Status 6927 ** METHOD: sqlite3 6928 ** 6929 ** ^This interface is used to retrieve runtime status information 6930 ** about a single [database connection]. ^The first argument is the 6931 ** database connection object to be interrogated. ^The second argument 6932 ** is an integer constant, taken from the set of 6933 ** [SQLITE_DBSTATUS options], that 6934 ** determines the parameter to interrogate. The set of 6935 ** [SQLITE_DBSTATUS options] is likely 6936 ** to grow in future releases of SQLite. 6937 ** 6938 ** ^The current value of the requested parameter is written into *pCur 6939 ** and the highest instantaneous value is written into *pHiwtr. ^If 6940 ** the resetFlg is true, then the highest instantaneous value is 6941 ** reset back down to the current value. 6942 ** 6943 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6944 ** non-zero [error code] on failure. 6945 ** 6946 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6947 */ 6948 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6949 6950 /* 6951 ** CAPI3REF: Status Parameters for database connections 6952 ** KEYWORDS: {SQLITE_DBSTATUS options} 6953 ** 6954 ** These constants are the available integer "verbs" that can be passed as 6955 ** the second argument to the [sqlite3_db_status()] interface. 6956 ** 6957 ** New verbs may be added in future releases of SQLite. Existing verbs 6958 ** might be discontinued. Applications should check the return code from 6959 ** [sqlite3_db_status()] to make sure that the call worked. 6960 ** The [sqlite3_db_status()] interface will return a non-zero error code 6961 ** if a discontinued or unsupported verb is invoked. 6962 ** 6963 ** <dl> 6964 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6965 ** <dd>This parameter returns the number of lookaside memory slots currently 6966 ** checked out.</dd>)^ 6967 ** 6968 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6969 ** <dd>This parameter returns the number malloc attempts that were 6970 ** satisfied using lookaside memory. Only the high-water value is meaningful; 6971 ** the current value is always zero.)^ 6972 ** 6973 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6974 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6975 ** <dd>This parameter returns the number malloc attempts that might have 6976 ** been satisfied using lookaside memory but failed due to the amount of 6977 ** memory requested being larger than the lookaside slot size. 6978 ** Only the high-water value is meaningful; 6979 ** the current value is always zero.)^ 6980 ** 6981 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6982 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6983 ** <dd>This parameter returns the number malloc attempts that might have 6984 ** been satisfied using lookaside memory but failed due to all lookaside 6985 ** memory already being in use. 6986 ** Only the high-water value is meaningful; 6987 ** the current value is always zero.)^ 6988 ** 6989 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6990 ** <dd>This parameter returns the approximate number of bytes of heap 6991 ** memory used by all pager caches associated with the database connection.)^ 6992 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6993 ** 6994 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 6995 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 6996 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 6997 ** pager cache is shared between two or more connections the bytes of heap 6998 ** memory used by that pager cache is divided evenly between the attached 6999 ** connections.)^ In other words, if none of the pager caches associated 7000 ** with the database connection are shared, this request returns the same 7001 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7002 ** shared, the value returned by this call will be smaller than that returned 7003 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7004 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7005 ** 7006 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7007 ** <dd>This parameter returns the approximate number of bytes of heap 7008 ** memory used to store the schema for all databases associated 7009 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7010 ** ^The full amount of memory used by the schemas is reported, even if the 7011 ** schema memory is shared with other database connections due to 7012 ** [shared cache mode] being enabled. 7013 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7014 ** 7015 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7016 ** <dd>This parameter returns the approximate number of bytes of heap 7017 ** and lookaside memory used by all prepared statements associated with 7018 ** the database connection.)^ 7019 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7020 ** </dd> 7021 ** 7022 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7023 ** <dd>This parameter returns the number of pager cache hits that have 7024 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7025 ** is always 0. 7026 ** </dd> 7027 ** 7028 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7029 ** <dd>This parameter returns the number of pager cache misses that have 7030 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7031 ** is always 0. 7032 ** </dd> 7033 ** 7034 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7035 ** <dd>This parameter returns the number of dirty cache entries that have 7036 ** been written to disk. Specifically, the number of pages written to the 7037 ** wal file in wal mode databases, or the number of pages written to the 7038 ** database file in rollback mode databases. Any pages written as part of 7039 ** transaction rollback or database recovery operations are not included. 7040 ** If an IO or other error occurs while writing a page to disk, the effect 7041 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7042 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7043 ** </dd> 7044 ** 7045 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7046 ** <dd>This parameter returns zero for the current value if and only if 7047 ** all foreign key constraints (deferred or immediate) have been 7048 ** resolved.)^ ^The highwater mark is always 0. 7049 ** </dd> 7050 ** </dl> 7051 */ 7052 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7053 #define SQLITE_DBSTATUS_CACHE_USED 1 7054 #define SQLITE_DBSTATUS_SCHEMA_USED 2 7055 #define SQLITE_DBSTATUS_STMT_USED 3 7056 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7057 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7058 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7059 #define SQLITE_DBSTATUS_CACHE_HIT 7 7060 #define SQLITE_DBSTATUS_CACHE_MISS 8 7061 #define SQLITE_DBSTATUS_CACHE_WRITE 9 7062 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 7063 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7064 #define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 7065 7066 7067 /* 7068 ** CAPI3REF: Prepared Statement Status 7069 ** METHOD: sqlite3_stmt 7070 ** 7071 ** ^(Each prepared statement maintains various 7072 ** [SQLITE_STMTSTATUS counters] that measure the number 7073 ** of times it has performed specific operations.)^ These counters can 7074 ** be used to monitor the performance characteristics of the prepared 7075 ** statements. For example, if the number of table steps greatly exceeds 7076 ** the number of table searches or result rows, that would tend to indicate 7077 ** that the prepared statement is using a full table scan rather than 7078 ** an index. 7079 ** 7080 ** ^(This interface is used to retrieve and reset counter values from 7081 ** a [prepared statement]. The first argument is the prepared statement 7082 ** object to be interrogated. The second argument 7083 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7084 ** to be interrogated.)^ 7085 ** ^The current value of the requested counter is returned. 7086 ** ^If the resetFlg is true, then the counter is reset to zero after this 7087 ** interface call returns. 7088 ** 7089 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7090 */ 7091 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7092 7093 /* 7094 ** CAPI3REF: Status Parameters for prepared statements 7095 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7096 ** 7097 ** These preprocessor macros define integer codes that name counter 7098 ** values associated with the [sqlite3_stmt_status()] interface. 7099 ** The meanings of the various counters are as follows: 7100 ** 7101 ** <dl> 7102 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7103 ** <dd>^This is the number of times that SQLite has stepped forward in 7104 ** a table as part of a full table scan. Large numbers for this counter 7105 ** may indicate opportunities for performance improvement through 7106 ** careful use of indices.</dd> 7107 ** 7108 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7109 ** <dd>^This is the number of sort operations that have occurred. 7110 ** A non-zero value in this counter may indicate an opportunity to 7111 ** improvement performance through careful use of indices.</dd> 7112 ** 7113 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7114 ** <dd>^This is the number of rows inserted into transient indices that 7115 ** were created automatically in order to help joins run faster. 7116 ** A non-zero value in this counter may indicate an opportunity to 7117 ** improvement performance by adding permanent indices that do not 7118 ** need to be reinitialized each time the statement is run.</dd> 7119 ** 7120 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7121 ** <dd>^This is the number of virtual machine operations executed 7122 ** by the prepared statement if that number is less than or equal 7123 ** to 2147483647. The number of virtual machine operations can be 7124 ** used as a proxy for the total work done by the prepared statement. 7125 ** If the number of virtual machine operations exceeds 2147483647 7126 ** then the value returned by this statement status code is undefined. 7127 ** </dd> 7128 ** </dl> 7129 */ 7130 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7131 #define SQLITE_STMTSTATUS_SORT 2 7132 #define SQLITE_STMTSTATUS_AUTOINDEX 3 7133 #define SQLITE_STMTSTATUS_VM_STEP 4 7134 7135 /* 7136 ** CAPI3REF: Custom Page Cache Object 7137 ** 7138 ** The sqlite3_pcache type is opaque. It is implemented by 7139 ** the pluggable module. The SQLite core has no knowledge of 7140 ** its size or internal structure and never deals with the 7141 ** sqlite3_pcache object except by holding and passing pointers 7142 ** to the object. 7143 ** 7144 ** See [sqlite3_pcache_methods2] for additional information. 7145 */ 7146 typedef struct sqlite3_pcache sqlite3_pcache; 7147 7148 /* 7149 ** CAPI3REF: Custom Page Cache Object 7150 ** 7151 ** The sqlite3_pcache_page object represents a single page in the 7152 ** page cache. The page cache will allocate instances of this 7153 ** object. Various methods of the page cache use pointers to instances 7154 ** of this object as parameters or as their return value. 7155 ** 7156 ** See [sqlite3_pcache_methods2] for additional information. 7157 */ 7158 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7159 struct sqlite3_pcache_page { 7160 void *pBuf; /* The content of the page */ 7161 void *pExtra; /* Extra information associated with the page */ 7162 }; 7163 7164 /* 7165 ** CAPI3REF: Application Defined Page Cache. 7166 ** KEYWORDS: {page cache} 7167 ** 7168 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7169 ** register an alternative page cache implementation by passing in an 7170 ** instance of the sqlite3_pcache_methods2 structure.)^ 7171 ** In many applications, most of the heap memory allocated by 7172 ** SQLite is used for the page cache. 7173 ** By implementing a 7174 ** custom page cache using this API, an application can better control 7175 ** the amount of memory consumed by SQLite, the way in which 7176 ** that memory is allocated and released, and the policies used to 7177 ** determine exactly which parts of a database file are cached and for 7178 ** how long. 7179 ** 7180 ** The alternative page cache mechanism is an 7181 ** extreme measure that is only needed by the most demanding applications. 7182 ** The built-in page cache is recommended for most uses. 7183 ** 7184 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7185 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7186 ** the application may discard the parameter after the call to 7187 ** [sqlite3_config()] returns.)^ 7188 ** 7189 ** [[the xInit() page cache method]] 7190 ** ^(The xInit() method is called once for each effective 7191 ** call to [sqlite3_initialize()])^ 7192 ** (usually only once during the lifetime of the process). ^(The xInit() 7193 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7194 ** The intent of the xInit() method is to set up global data structures 7195 ** required by the custom page cache implementation. 7196 ** ^(If the xInit() method is NULL, then the 7197 ** built-in default page cache is used instead of the application defined 7198 ** page cache.)^ 7199 ** 7200 ** [[the xShutdown() page cache method]] 7201 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7202 ** It can be used to clean up 7203 ** any outstanding resources before process shutdown, if required. 7204 ** ^The xShutdown() method may be NULL. 7205 ** 7206 ** ^SQLite automatically serializes calls to the xInit method, 7207 ** so the xInit method need not be threadsafe. ^The 7208 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 7209 ** not need to be threadsafe either. All other methods must be threadsafe 7210 ** in multithreaded applications. 7211 ** 7212 ** ^SQLite will never invoke xInit() more than once without an intervening 7213 ** call to xShutdown(). 7214 ** 7215 ** [[the xCreate() page cache methods]] 7216 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 7217 ** SQLite will typically create one cache instance for each open database file, 7218 ** though this is not guaranteed. ^The 7219 ** first parameter, szPage, is the size in bytes of the pages that must 7220 ** be allocated by the cache. ^szPage will always a power of two. ^The 7221 ** second parameter szExtra is a number of bytes of extra storage 7222 ** associated with each page cache entry. ^The szExtra parameter will 7223 ** a number less than 250. SQLite will use the 7224 ** extra szExtra bytes on each page to store metadata about the underlying 7225 ** database page on disk. The value passed into szExtra depends 7226 ** on the SQLite version, the target platform, and how SQLite was compiled. 7227 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7228 ** created will be used to cache database pages of a file stored on disk, or 7229 ** false if it is used for an in-memory database. The cache implementation 7230 ** does not have to do anything special based with the value of bPurgeable; 7231 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7232 ** never invoke xUnpin() except to deliberately delete a page. 7233 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7234 ** false will always have the "discard" flag set to true. 7235 ** ^Hence, a cache created with bPurgeable false will 7236 ** never contain any unpinned pages. 7237 ** 7238 ** [[the xCachesize() page cache method]] 7239 ** ^(The xCachesize() method may be called at any time by SQLite to set the 7240 ** suggested maximum cache-size (number of pages stored by) the cache 7241 ** instance passed as the first argument. This is the value configured using 7242 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7243 ** parameter, the implementation is not required to do anything with this 7244 ** value; it is advisory only. 7245 ** 7246 ** [[the xPagecount() page cache methods]] 7247 ** The xPagecount() method must return the number of pages currently 7248 ** stored in the cache, both pinned and unpinned. 7249 ** 7250 ** [[the xFetch() page cache methods]] 7251 ** The xFetch() method locates a page in the cache and returns a pointer to 7252 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7253 ** The pBuf element of the returned sqlite3_pcache_page object will be a 7254 ** pointer to a buffer of szPage bytes used to store the content of a 7255 ** single database page. The pExtra element of sqlite3_pcache_page will be 7256 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 7257 ** for each entry in the page cache. 7258 ** 7259 ** The page to be fetched is determined by the key. ^The minimum key value 7260 ** is 1. After it has been retrieved using xFetch, the page is considered 7261 ** to be "pinned". 7262 ** 7263 ** If the requested page is already in the page cache, then the page cache 7264 ** implementation must return a pointer to the page buffer with its content 7265 ** intact. If the requested page is not already in the cache, then the 7266 ** cache implementation should use the value of the createFlag 7267 ** parameter to help it determined what action to take: 7268 ** 7269 ** <table border=1 width=85% align=center> 7270 ** <tr><th> createFlag <th> Behavior when page is not already in cache 7271 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7272 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7273 ** Otherwise return NULL. 7274 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7275 ** NULL if allocating a new page is effectively impossible. 7276 ** </table> 7277 ** 7278 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7279 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 7280 ** failed.)^ In between the to xFetch() calls, SQLite may 7281 ** attempt to unpin one or more cache pages by spilling the content of 7282 ** pinned pages to disk and synching the operating system disk cache. 7283 ** 7284 ** [[the xUnpin() page cache method]] 7285 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7286 ** as its second argument. If the third parameter, discard, is non-zero, 7287 ** then the page must be evicted from the cache. 7288 ** ^If the discard parameter is 7289 ** zero, then the page may be discarded or retained at the discretion of 7290 ** page cache implementation. ^The page cache implementation 7291 ** may choose to evict unpinned pages at any time. 7292 ** 7293 ** The cache must not perform any reference counting. A single 7294 ** call to xUnpin() unpins the page regardless of the number of prior calls 7295 ** to xFetch(). 7296 ** 7297 ** [[the xRekey() page cache methods]] 7298 ** The xRekey() method is used to change the key value associated with the 7299 ** page passed as the second argument. If the cache 7300 ** previously contains an entry associated with newKey, it must be 7301 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7302 ** to be pinned. 7303 ** 7304 ** When SQLite calls the xTruncate() method, the cache must discard all 7305 ** existing cache entries with page numbers (keys) greater than or equal 7306 ** to the value of the iLimit parameter passed to xTruncate(). If any 7307 ** of these pages are pinned, they are implicitly unpinned, meaning that 7308 ** they can be safely discarded. 7309 ** 7310 ** [[the xDestroy() page cache method]] 7311 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7312 ** All resources associated with the specified cache should be freed. ^After 7313 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7314 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7315 ** functions. 7316 ** 7317 ** [[the xShrink() page cache method]] 7318 ** ^SQLite invokes the xShrink() method when it wants the page cache to 7319 ** free up as much of heap memory as possible. The page cache implementation 7320 ** is not obligated to free any memory, but well-behaved implementations should 7321 ** do their best. 7322 */ 7323 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7324 struct sqlite3_pcache_methods2 { 7325 int iVersion; 7326 void *pArg; 7327 int (*xInit)(void*); 7328 void (*xShutdown)(void*); 7329 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7330 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7331 int (*xPagecount)(sqlite3_pcache*); 7332 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7333 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7334 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7335 unsigned oldKey, unsigned newKey); 7336 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7337 void (*xDestroy)(sqlite3_pcache*); 7338 void (*xShrink)(sqlite3_pcache*); 7339 }; 7340 7341 /* 7342 ** This is the obsolete pcache_methods object that has now been replaced 7343 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7344 ** retained in the header file for backwards compatibility only. 7345 */ 7346 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7347 struct sqlite3_pcache_methods { 7348 void *pArg; 7349 int (*xInit)(void*); 7350 void (*xShutdown)(void*); 7351 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7352 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7353 int (*xPagecount)(sqlite3_pcache*); 7354 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7355 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7356 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7357 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7358 void (*xDestroy)(sqlite3_pcache*); 7359 }; 7360 7361 7362 /* 7363 ** CAPI3REF: Online Backup Object 7364 ** 7365 ** The sqlite3_backup object records state information about an ongoing 7366 ** online backup operation. ^The sqlite3_backup object is created by 7367 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 7368 ** [sqlite3_backup_finish()]. 7369 ** 7370 ** See Also: [Using the SQLite Online Backup API] 7371 */ 7372 typedef struct sqlite3_backup sqlite3_backup; 7373 7374 /* 7375 ** CAPI3REF: Online Backup API. 7376 ** 7377 ** The backup API copies the content of one database into another. 7378 ** It is useful either for creating backups of databases or 7379 ** for copying in-memory databases to or from persistent files. 7380 ** 7381 ** See Also: [Using the SQLite Online Backup API] 7382 ** 7383 ** ^SQLite holds a write transaction open on the destination database file 7384 ** for the duration of the backup operation. 7385 ** ^The source database is read-locked only while it is being read; 7386 ** it is not locked continuously for the entire backup operation. 7387 ** ^Thus, the backup may be performed on a live source database without 7388 ** preventing other database connections from 7389 ** reading or writing to the source database while the backup is underway. 7390 ** 7391 ** ^(To perform a backup operation: 7392 ** <ol> 7393 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7394 ** backup, 7395 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7396 ** the data between the two databases, and finally 7397 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7398 ** associated with the backup operation. 7399 ** </ol>)^ 7400 ** There should be exactly one call to sqlite3_backup_finish() for each 7401 ** successful call to sqlite3_backup_init(). 7402 ** 7403 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7404 ** 7405 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7406 ** [database connection] associated with the destination database 7407 ** and the database name, respectively. 7408 ** ^The database name is "main" for the main database, "temp" for the 7409 ** temporary database, or the name specified after the AS keyword in 7410 ** an [ATTACH] statement for an attached database. 7411 ** ^The S and M arguments passed to 7412 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7413 ** and database name of the source database, respectively. 7414 ** ^The source and destination [database connections] (parameters S and D) 7415 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7416 ** an error. 7417 ** 7418 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7419 ** there is already a read or read-write transaction open on the 7420 ** destination database. 7421 ** 7422 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7423 ** returned and an error code and error message are stored in the 7424 ** destination [database connection] D. 7425 ** ^The error code and message for the failed call to sqlite3_backup_init() 7426 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7427 ** [sqlite3_errmsg16()] functions. 7428 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 7429 ** [sqlite3_backup] object. 7430 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7431 ** sqlite3_backup_finish() functions to perform the specified backup 7432 ** operation. 7433 ** 7434 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7435 ** 7436 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7437 ** the source and destination databases specified by [sqlite3_backup] object B. 7438 ** ^If N is negative, all remaining source pages are copied. 7439 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7440 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 7441 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7442 ** from source to destination, then it returns [SQLITE_DONE]. 7443 ** ^If an error occurs while running sqlite3_backup_step(B,N), 7444 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 7445 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7446 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7447 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7448 ** 7449 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7450 ** <ol> 7451 ** <li> the destination database was opened read-only, or 7452 ** <li> the destination database is using write-ahead-log journaling 7453 ** and the destination and source page sizes differ, or 7454 ** <li> the destination database is an in-memory database and the 7455 ** destination and source page sizes differ. 7456 ** </ol>)^ 7457 ** 7458 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7459 ** the [sqlite3_busy_handler | busy-handler function] 7460 ** is invoked (if one is specified). ^If the 7461 ** busy-handler returns non-zero before the lock is available, then 7462 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7463 ** sqlite3_backup_step() can be retried later. ^If the source 7464 ** [database connection] 7465 ** is being used to write to the source database when sqlite3_backup_step() 7466 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7467 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 7468 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7469 ** [SQLITE_READONLY] is returned, then 7470 ** there is no point in retrying the call to sqlite3_backup_step(). These 7471 ** errors are considered fatal.)^ The application must accept 7472 ** that the backup operation has failed and pass the backup operation handle 7473 ** to the sqlite3_backup_finish() to release associated resources. 7474 ** 7475 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7476 ** on the destination file. ^The exclusive lock is not released until either 7477 ** sqlite3_backup_finish() is called or the backup operation is complete 7478 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7479 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 7480 ** lasts for the duration of the sqlite3_backup_step() call. 7481 ** ^Because the source database is not locked between calls to 7482 ** sqlite3_backup_step(), the source database may be modified mid-way 7483 ** through the backup process. ^If the source database is modified by an 7484 ** external process or via a database connection other than the one being 7485 ** used by the backup operation, then the backup will be automatically 7486 ** restarted by the next call to sqlite3_backup_step(). ^If the source 7487 ** database is modified by the using the same database connection as is used 7488 ** by the backup operation, then the backup database is automatically 7489 ** updated at the same time. 7490 ** 7491 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7492 ** 7493 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7494 ** application wishes to abandon the backup operation, the application 7495 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7496 ** ^The sqlite3_backup_finish() interfaces releases all 7497 ** resources associated with the [sqlite3_backup] object. 7498 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7499 ** active write-transaction on the destination database is rolled back. 7500 ** The [sqlite3_backup] object is invalid 7501 ** and may not be used following a call to sqlite3_backup_finish(). 7502 ** 7503 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7504 ** sqlite3_backup_step() errors occurred, regardless or whether or not 7505 ** sqlite3_backup_step() completed. 7506 ** ^If an out-of-memory condition or IO error occurred during any prior 7507 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7508 ** sqlite3_backup_finish() returns the corresponding [error code]. 7509 ** 7510 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7511 ** is not a permanent error and does not affect the return value of 7512 ** sqlite3_backup_finish(). 7513 ** 7514 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7515 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7516 ** 7517 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7518 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7519 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7520 ** in the source database at the conclusion of the most recent 7521 ** sqlite3_backup_step(). 7522 ** ^(The values returned by these functions are only updated by 7523 ** sqlite3_backup_step(). If the source database is modified in a way that 7524 ** changes the size of the source database or the number of pages remaining, 7525 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7526 ** and sqlite3_backup_remaining() until after the next 7527 ** sqlite3_backup_step().)^ 7528 ** 7529 ** <b>Concurrent Usage of Database Handles</b> 7530 ** 7531 ** ^The source [database connection] may be used by the application for other 7532 ** purposes while a backup operation is underway or being initialized. 7533 ** ^If SQLite is compiled and configured to support threadsafe database 7534 ** connections, then the source database connection may be used concurrently 7535 ** from within other threads. 7536 ** 7537 ** However, the application must guarantee that the destination 7538 ** [database connection] is not passed to any other API (by any thread) after 7539 ** sqlite3_backup_init() is called and before the corresponding call to 7540 ** sqlite3_backup_finish(). SQLite does not currently check to see 7541 ** if the application incorrectly accesses the destination [database connection] 7542 ** and so no error code is reported, but the operations may malfunction 7543 ** nevertheless. Use of the destination database connection while a 7544 ** backup is in progress might also also cause a mutex deadlock. 7545 ** 7546 ** If running in [shared cache mode], the application must 7547 ** guarantee that the shared cache used by the destination database 7548 ** is not accessed while the backup is running. In practice this means 7549 ** that the application must guarantee that the disk file being 7550 ** backed up to is not accessed by any connection within the process, 7551 ** not just the specific connection that was passed to sqlite3_backup_init(). 7552 ** 7553 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7554 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7555 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7556 ** APIs are not strictly speaking threadsafe. If they are invoked at the 7557 ** same time as another thread is invoking sqlite3_backup_step() it is 7558 ** possible that they return invalid values. 7559 */ 7560 SQLITE_API sqlite3_backup *sqlite3_backup_init( 7561 sqlite3 *pDest, /* Destination database handle */ 7562 const char *zDestName, /* Destination database name */ 7563 sqlite3 *pSource, /* Source database handle */ 7564 const char *zSourceName /* Source database name */ 7565 ); 7566 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7567 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 7568 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 7569 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 7570 7571 /* 7572 ** CAPI3REF: Unlock Notification 7573 ** METHOD: sqlite3 7574 ** 7575 ** ^When running in shared-cache mode, a database operation may fail with 7576 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7577 ** individual tables within the shared-cache cannot be obtained. See 7578 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7579 ** ^This API may be used to register a callback that SQLite will invoke 7580 ** when the connection currently holding the required lock relinquishes it. 7581 ** ^This API is only available if the library was compiled with the 7582 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7583 ** 7584 ** See Also: [Using the SQLite Unlock Notification Feature]. 7585 ** 7586 ** ^Shared-cache locks are released when a database connection concludes 7587 ** its current transaction, either by committing it or rolling it back. 7588 ** 7589 ** ^When a connection (known as the blocked connection) fails to obtain a 7590 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7591 ** identity of the database connection (the blocking connection) that 7592 ** has locked the required resource is stored internally. ^After an 7593 ** application receives an SQLITE_LOCKED error, it may call the 7594 ** sqlite3_unlock_notify() method with the blocked connection handle as 7595 ** the first argument to register for a callback that will be invoked 7596 ** when the blocking connections current transaction is concluded. ^The 7597 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7598 ** call that concludes the blocking connections transaction. 7599 ** 7600 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7601 ** there is a chance that the blocking connection will have already 7602 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7603 ** If this happens, then the specified callback is invoked immediately, 7604 ** from within the call to sqlite3_unlock_notify().)^ 7605 ** 7606 ** ^If the blocked connection is attempting to obtain a write-lock on a 7607 ** shared-cache table, and more than one other connection currently holds 7608 ** a read-lock on the same table, then SQLite arbitrarily selects one of 7609 ** the other connections to use as the blocking connection. 7610 ** 7611 ** ^(There may be at most one unlock-notify callback registered by a 7612 ** blocked connection. If sqlite3_unlock_notify() is called when the 7613 ** blocked connection already has a registered unlock-notify callback, 7614 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7615 ** called with a NULL pointer as its second argument, then any existing 7616 ** unlock-notify callback is canceled. ^The blocked connections 7617 ** unlock-notify callback may also be canceled by closing the blocked 7618 ** connection using [sqlite3_close()]. 7619 ** 7620 ** The unlock-notify callback is not reentrant. If an application invokes 7621 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7622 ** crash or deadlock may be the result. 7623 ** 7624 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7625 ** returns SQLITE_OK. 7626 ** 7627 ** <b>Callback Invocation Details</b> 7628 ** 7629 ** When an unlock-notify callback is registered, the application provides a 7630 ** single void* pointer that is passed to the callback when it is invoked. 7631 ** However, the signature of the callback function allows SQLite to pass 7632 ** it an array of void* context pointers. The first argument passed to 7633 ** an unlock-notify callback is a pointer to an array of void* pointers, 7634 ** and the second is the number of entries in the array. 7635 ** 7636 ** When a blocking connections transaction is concluded, there may be 7637 ** more than one blocked connection that has registered for an unlock-notify 7638 ** callback. ^If two or more such blocked connections have specified the 7639 ** same callback function, then instead of invoking the callback function 7640 ** multiple times, it is invoked once with the set of void* context pointers 7641 ** specified by the blocked connections bundled together into an array. 7642 ** This gives the application an opportunity to prioritize any actions 7643 ** related to the set of unblocked database connections. 7644 ** 7645 ** <b>Deadlock Detection</b> 7646 ** 7647 ** Assuming that after registering for an unlock-notify callback a 7648 ** database waits for the callback to be issued before taking any further 7649 ** action (a reasonable assumption), then using this API may cause the 7650 ** application to deadlock. For example, if connection X is waiting for 7651 ** connection Y's transaction to be concluded, and similarly connection 7652 ** Y is waiting on connection X's transaction, then neither connection 7653 ** will proceed and the system may remain deadlocked indefinitely. 7654 ** 7655 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7656 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7657 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7658 ** unlock-notify callback is registered. The system is said to be in 7659 ** a deadlocked state if connection A has registered for an unlock-notify 7660 ** callback on the conclusion of connection B's transaction, and connection 7661 ** B has itself registered for an unlock-notify callback when connection 7662 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7663 ** the system is also considered to be deadlocked if connection B has 7664 ** registered for an unlock-notify callback on the conclusion of connection 7665 ** C's transaction, where connection C is waiting on connection A. ^Any 7666 ** number of levels of indirection are allowed. 7667 ** 7668 ** <b>The "DROP TABLE" Exception</b> 7669 ** 7670 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7671 ** always appropriate to call sqlite3_unlock_notify(). There is however, 7672 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7673 ** SQLite checks if there are any currently executing SELECT statements 7674 ** that belong to the same connection. If there are, SQLITE_LOCKED is 7675 ** returned. In this case there is no "blocking connection", so invoking 7676 ** sqlite3_unlock_notify() results in the unlock-notify callback being 7677 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7678 ** or "DROP INDEX" query, an infinite loop might be the result. 7679 ** 7680 ** One way around this problem is to check the extended error code returned 7681 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7682 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7683 ** the special "DROP TABLE/INDEX" case, the extended error code is just 7684 ** SQLITE_LOCKED.)^ 7685 */ 7686 SQLITE_API int sqlite3_unlock_notify( 7687 sqlite3 *pBlocked, /* Waiting connection */ 7688 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7689 void *pNotifyArg /* Argument to pass to xNotify */ 7690 ); 7691 7692 7693 /* 7694 ** CAPI3REF: String Comparison 7695 ** 7696 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7697 ** and extensions to compare the contents of two buffers containing UTF-8 7698 ** strings in a case-independent fashion, using the same definition of "case 7699 ** independence" that SQLite uses internally when comparing identifiers. 7700 */ 7701 SQLITE_API int sqlite3_stricmp(const char *, const char *); 7702 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 7703 7704 /* 7705 ** CAPI3REF: String Globbing 7706 * 7707 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7708 ** string X matches the [GLOB] pattern P. 7709 ** ^The definition of [GLOB] pattern matching used in 7710 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7711 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7712 ** is case sensitive. 7713 ** 7714 ** Note that this routine returns zero on a match and non-zero if the strings 7715 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7716 ** 7717 ** See also: [sqlite3_strlike()]. 7718 */ 7719 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 7720 7721 /* 7722 ** CAPI3REF: String LIKE Matching 7723 * 7724 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7725 ** string X matches the [LIKE] pattern P with escape character E. 7726 ** ^The definition of [LIKE] pattern matching used in 7727 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7728 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7729 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7730 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7731 ** insensitive - equivalent upper and lower case ASCII characters match 7732 ** one another. 7733 ** 7734 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7735 ** only ASCII characters are case folded. 7736 ** 7737 ** Note that this routine returns zero on a match and non-zero if the strings 7738 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7739 ** 7740 ** See also: [sqlite3_strglob()]. 7741 */ 7742 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7743 7744 /* 7745 ** CAPI3REF: Error Logging Interface 7746 ** 7747 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7748 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7749 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7750 ** used with [sqlite3_snprintf()] to generate the final output string. 7751 ** 7752 ** The sqlite3_log() interface is intended for use by extensions such as 7753 ** virtual tables, collating functions, and SQL functions. While there is 7754 ** nothing to prevent an application from calling sqlite3_log(), doing so 7755 ** is considered bad form. 7756 ** 7757 ** The zFormat string must not be NULL. 7758 ** 7759 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7760 ** will not use dynamically allocated memory. The log message is stored in 7761 ** a fixed-length buffer on the stack. If the log message is longer than 7762 ** a few hundred characters, it will be truncated to the length of the 7763 ** buffer. 7764 */ 7765 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 7766 7767 /* 7768 ** CAPI3REF: Write-Ahead Log Commit Hook 7769 ** METHOD: sqlite3 7770 ** 7771 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 7772 ** is invoked each time data is committed to a database in wal mode. 7773 ** 7774 ** ^(The callback is invoked by SQLite after the commit has taken place and 7775 ** the associated write-lock on the database released)^, so the implementation 7776 ** may read, write or [checkpoint] the database as required. 7777 ** 7778 ** ^The first parameter passed to the callback function when it is invoked 7779 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 7780 ** registering the callback. ^The second is a copy of the database handle. 7781 ** ^The third parameter is the name of the database that was written to - 7782 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7783 ** is the number of pages currently in the write-ahead log file, 7784 ** including those that were just committed. 7785 ** 7786 ** The callback function should normally return [SQLITE_OK]. ^If an error 7787 ** code is returned, that error will propagate back up through the 7788 ** SQLite code base to cause the statement that provoked the callback 7789 ** to report an error, though the commit will have still occurred. If the 7790 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7791 ** that does not correspond to any valid SQLite error code, the results 7792 ** are undefined. 7793 ** 7794 ** A single database handle may have at most a single write-ahead log callback 7795 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7796 ** previously registered write-ahead log callback. ^Note that the 7797 ** [sqlite3_wal_autocheckpoint()] interface and the 7798 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7799 ** overwrite any prior [sqlite3_wal_hook()] settings. 7800 */ 7801 SQLITE_API void *sqlite3_wal_hook( 7802 sqlite3*, 7803 int(*)(void *,sqlite3*,const char*,int), 7804 void* 7805 ); 7806 7807 /* 7808 ** CAPI3REF: Configure an auto-checkpoint 7809 ** METHOD: sqlite3 7810 ** 7811 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7812 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 7813 ** to automatically [checkpoint] 7814 ** after committing a transaction if there are N or 7815 ** more frames in the [write-ahead log] file. ^Passing zero or 7816 ** a negative value as the nFrame parameter disables automatic 7817 ** checkpoints entirely. 7818 ** 7819 ** ^The callback registered by this function replaces any existing callback 7820 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7821 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7822 ** configured by this function. 7823 ** 7824 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7825 ** from SQL. 7826 ** 7827 ** ^Checkpoints initiated by this mechanism are 7828 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7829 ** 7830 ** ^Every new [database connection] defaults to having the auto-checkpoint 7831 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7832 ** pages. The use of this interface 7833 ** is only necessary if the default setting is found to be suboptimal 7834 ** for a particular application. 7835 */ 7836 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7837 7838 /* 7839 ** CAPI3REF: Checkpoint a database 7840 ** METHOD: sqlite3 7841 ** 7842 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7843 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7844 ** 7845 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7846 ** [write-ahead log] for database X on [database connection] D to be 7847 ** transferred into the database file and for the write-ahead log to 7848 ** be reset. See the [checkpointing] documentation for addition 7849 ** information. 7850 ** 7851 ** This interface used to be the only way to cause a checkpoint to 7852 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7853 ** interface was added. This interface is retained for backwards 7854 ** compatibility and as a convenience for applications that need to manually 7855 ** start a callback but which do not need the full power (and corresponding 7856 ** complication) of [sqlite3_wal_checkpoint_v2()]. 7857 */ 7858 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7859 7860 /* 7861 ** CAPI3REF: Checkpoint a database 7862 ** METHOD: sqlite3 7863 ** 7864 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7865 ** operation on database X of [database connection] D in mode M. Status 7866 ** information is written back into integers pointed to by L and C.)^ 7867 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 7868 ** 7869 ** <dl> 7870 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7871 ** ^Checkpoint as many frames as possible without waiting for any database 7872 ** readers or writers to finish, then sync the database file if all frames 7873 ** in the log were checkpointed. ^The [busy-handler callback] 7874 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7875 ** ^On the other hand, passive mode might leave the checkpoint unfinished 7876 ** if there are concurrent readers or writers. 7877 ** 7878 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 7879 ** ^This mode blocks (it invokes the 7880 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 7881 ** database writer and all readers are reading from the most recent database 7882 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 7883 ** database file. ^This mode blocks new database writers while it is pending, 7884 ** but new database readers are allowed to continue unimpeded. 7885 ** 7886 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7887 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7888 ** that after checkpointing the log file it blocks (calls the 7889 ** [busy-handler callback]) 7890 ** until all readers are reading from the database file only. ^This ensures 7891 ** that the next writer will restart the log file from the beginning. 7892 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7893 ** database writer attempts while it is pending, but does not impede readers. 7894 ** 7895 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7896 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7897 ** addition that it also truncates the log file to zero bytes just prior 7898 ** to a successful return. 7899 ** </dl> 7900 ** 7901 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7902 ** the log file or to -1 if the checkpoint could not run because 7903 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7904 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7905 ** log file (including any that were already checkpointed before the function 7906 ** was called) or to -1 if the checkpoint could not run due to an error or 7907 ** because the database is not in WAL mode. ^Note that upon successful 7908 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7909 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7910 ** 7911 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7912 ** any other process is running a checkpoint operation at the same time, the 7913 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7914 ** busy-handler configured, it will not be invoked in this case. 7915 ** 7916 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7917 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7918 ** obtained immediately, and a busy-handler is configured, it is invoked and 7919 ** the writer lock retried until either the busy-handler returns 0 or the lock 7920 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 7921 ** database readers as described above. ^If the busy-handler returns 0 before 7922 ** the writer lock is obtained or while waiting for database readers, the 7923 ** checkpoint operation proceeds from that point in the same way as 7924 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7925 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 7926 ** 7927 ** ^If parameter zDb is NULL or points to a zero length string, then the 7928 ** specified operation is attempted on all WAL databases [attached] to 7929 ** [database connection] db. In this case the 7930 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7931 ** an SQLITE_BUSY error is encountered when processing one or more of the 7932 ** attached WAL databases, the operation is still attempted on any remaining 7933 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7934 ** error occurs while processing an attached database, processing is abandoned 7935 ** and the error code is returned to the caller immediately. ^If no error 7936 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7937 ** databases, SQLITE_OK is returned. 7938 ** 7939 ** ^If database zDb is the name of an attached database that is not in WAL 7940 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7941 ** zDb is not NULL (or a zero length string) and is not the name of any 7942 ** attached database, SQLITE_ERROR is returned to the caller. 7943 ** 7944 ** ^Unless it returns SQLITE_MISUSE, 7945 ** the sqlite3_wal_checkpoint_v2() interface 7946 ** sets the error information that is queried by 7947 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7948 ** 7949 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7950 ** from SQL. 7951 */ 7952 SQLITE_API int sqlite3_wal_checkpoint_v2( 7953 sqlite3 *db, /* Database handle */ 7954 const char *zDb, /* Name of attached database (or NULL) */ 7955 int eMode, /* SQLITE_CHECKPOINT_* value */ 7956 int *pnLog, /* OUT: Size of WAL log in frames */ 7957 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7958 ); 7959 7960 /* 7961 ** CAPI3REF: Checkpoint Mode Values 7962 ** KEYWORDS: {checkpoint mode} 7963 ** 7964 ** These constants define all valid values for the "checkpoint mode" passed 7965 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7966 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7967 ** meaning of each of these checkpoint modes. 7968 */ 7969 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7970 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7971 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7972 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7973 7974 /* 7975 ** CAPI3REF: Virtual Table Interface Configuration 7976 ** 7977 ** This function may be called by either the [xConnect] or [xCreate] method 7978 ** of a [virtual table] implementation to configure 7979 ** various facets of the virtual table interface. 7980 ** 7981 ** If this interface is invoked outside the context of an xConnect or 7982 ** xCreate virtual table method then the behavior is undefined. 7983 ** 7984 ** At present, there is only one option that may be configured using 7985 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7986 ** may be added in the future. 7987 */ 7988 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 7989 7990 /* 7991 ** CAPI3REF: Virtual Table Configuration Options 7992 ** 7993 ** These macros define the various options to the 7994 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7995 ** can use to customize and optimize their behavior. 7996 ** 7997 ** <dl> 7998 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7999 ** <dd>Calls of the form 8000 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8001 ** where X is an integer. If X is zero, then the [virtual table] whose 8002 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8003 ** support constraints. In this configuration (which is the default) if 8004 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8005 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8006 ** specified as part of the users SQL statement, regardless of the actual 8007 ** ON CONFLICT mode specified. 8008 ** 8009 ** If X is non-zero, then the virtual table implementation guarantees 8010 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8011 ** any modifications to internal or persistent data structures have been made. 8012 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8013 ** is able to roll back a statement or database transaction, and abandon 8014 ** or continue processing the current SQL statement as appropriate. 8015 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8016 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8017 ** had been ABORT. 8018 ** 8019 ** Virtual table implementations that are required to handle OR REPLACE 8020 ** must do so within the [xUpdate] method. If a call to the 8021 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8022 ** CONFLICT policy is REPLACE, the virtual table implementation should 8023 ** silently replace the appropriate rows within the xUpdate callback and 8024 ** return SQLITE_OK. Or, if this is not possible, it may return 8025 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8026 ** constraint handling. 8027 ** </dl> 8028 */ 8029 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8030 8031 /* 8032 ** CAPI3REF: Determine The Virtual Table Conflict Policy 8033 ** 8034 ** This function may only be called from within a call to the [xUpdate] method 8035 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8036 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8037 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8038 ** of the SQL statement that triggered the call to the [xUpdate] method of the 8039 ** [virtual table]. 8040 */ 8041 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8042 8043 /* 8044 ** CAPI3REF: Conflict resolution modes 8045 ** KEYWORDS: {conflict resolution mode} 8046 ** 8047 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 8048 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 8049 ** is for the SQL statement being evaluated. 8050 ** 8051 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 8052 ** return value from the [sqlite3_set_authorizer()] callback and that 8053 ** [SQLITE_ABORT] is also a [result code]. 8054 */ 8055 #define SQLITE_ROLLBACK 1 8056 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8057 #define SQLITE_FAIL 3 8058 /* #define SQLITE_ABORT 4 // Also an error code */ 8059 #define SQLITE_REPLACE 5 8060 8061 /* 8062 ** CAPI3REF: Prepared Statement Scan Status Opcodes 8063 ** KEYWORDS: {scanstatus options} 8064 ** 8065 ** The following constants can be used for the T parameter to the 8066 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8067 ** different metric for sqlite3_stmt_scanstatus() to return. 8068 ** 8069 ** When the value returned to V is a string, space to hold that string is 8070 ** managed by the prepared statement S and will be automatically freed when 8071 ** S is finalized. 8072 ** 8073 ** <dl> 8074 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8075 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8076 ** set to the total number of times that the X-th loop has run.</dd> 8077 ** 8078 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8079 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8080 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 8081 ** 8082 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8083 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 8084 ** query planner's estimate for the average number of rows output from each 8085 ** iteration of the X-th loop. If the query planner's estimates was accurate, 8086 ** then this value will approximate the quotient NVISIT/NLOOP and the 8087 ** product of this value for all prior loops with the same SELECTID will 8088 ** be the NLOOP value for the current loop. 8089 ** 8090 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8091 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8092 ** to a zero-terminated UTF-8 string containing the name of the index or table 8093 ** used for the X-th loop. 8094 ** 8095 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8096 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8097 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8098 ** description for the X-th loop. 8099 ** 8100 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8101 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8102 ** "select-id" for the X-th loop. The select-id identifies which query or 8103 ** subquery the loop is part of. The main query has a select-id of zero. 8104 ** The select-id is the same value as is output in the first column 8105 ** of an [EXPLAIN QUERY PLAN] query. 8106 ** </dl> 8107 */ 8108 #define SQLITE_SCANSTAT_NLOOP 0 8109 #define SQLITE_SCANSTAT_NVISIT 1 8110 #define SQLITE_SCANSTAT_EST 2 8111 #define SQLITE_SCANSTAT_NAME 3 8112 #define SQLITE_SCANSTAT_EXPLAIN 4 8113 #define SQLITE_SCANSTAT_SELECTID 5 8114 8115 /* 8116 ** CAPI3REF: Prepared Statement Scan Status 8117 ** METHOD: sqlite3_stmt 8118 ** 8119 ** This interface returns information about the predicted and measured 8120 ** performance for pStmt. Advanced applications can use this 8121 ** interface to compare the predicted and the measured performance and 8122 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8123 ** 8124 ** Since this interface is expected to be rarely used, it is only 8125 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8126 ** compile-time option. 8127 ** 8128 ** The "iScanStatusOp" parameter determines which status information to return. 8129 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8130 ** of this interface is undefined. 8131 ** ^The requested measurement is written into a variable pointed to by 8132 ** the "pOut" parameter. 8133 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8134 ** Loops are numbered starting from zero. ^If idx is out of range - less than 8135 ** zero or greater than or equal to the total number of loops used to implement 8136 ** the statement - a non-zero value is returned and the variable that pOut 8137 ** points to is unchanged. 8138 ** 8139 ** ^Statistics might not be available for all loops in all statements. ^In cases 8140 ** where there exist loops with no available statistics, this function behaves 8141 ** as if the loop did not exist - it returns non-zero and leave the variable 8142 ** that pOut points to unchanged. 8143 ** 8144 ** See also: [sqlite3_stmt_scanstatus_reset()] 8145 */ 8146 SQLITE_API int sqlite3_stmt_scanstatus( 8147 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8148 int idx, /* Index of loop to report on */ 8149 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8150 void *pOut /* Result written here */ 8151 ); 8152 8153 /* 8154 ** CAPI3REF: Zero Scan-Status Counters 8155 ** METHOD: sqlite3_stmt 8156 ** 8157 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8158 ** 8159 ** This API is only available if the library is built with pre-processor 8160 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8161 */ 8162 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8163 8164 /* 8165 ** CAPI3REF: Flush caches to disk mid-transaction 8166 ** 8167 ** ^If a write-transaction is open on [database connection] D when the 8168 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8169 ** pages in the pager-cache that are not currently in use are written out 8170 ** to disk. A dirty page may be in use if a database cursor created by an 8171 ** active SQL statement is reading from it, or if it is page 1 of a database 8172 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8173 ** interface flushes caches for all schemas - "main", "temp", and 8174 ** any [attached] databases. 8175 ** 8176 ** ^If this function needs to obtain extra database locks before dirty pages 8177 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 8178 ** immediately and there is a busy-handler callback configured, it is invoked 8179 ** in the usual manner. ^If the required lock still cannot be obtained, then 8180 ** the database is skipped and an attempt made to flush any dirty pages 8181 ** belonging to the next (if any) database. ^If any databases are skipped 8182 ** because locks cannot be obtained, but no other error occurs, this 8183 ** function returns SQLITE_BUSY. 8184 ** 8185 ** ^If any other error occurs while flushing dirty pages to disk (for 8186 ** example an IO error or out-of-memory condition), then processing is 8187 ** abandoned and an SQLite [error code] is returned to the caller immediately. 8188 ** 8189 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8190 ** 8191 ** ^This function does not set the database handle error code or message 8192 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8193 */ 8194 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8195 8196 /* 8197 ** CAPI3REF: The pre-update hook. 8198 ** 8199 ** ^These interfaces are only available if SQLite is compiled using the 8200 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8201 ** 8202 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8203 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8204 ** on a database table. 8205 ** ^At most one preupdate hook may be registered at a time on a single 8206 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8207 ** the previous setting. 8208 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8209 ** with a NULL pointer as the second parameter. 8210 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8211 ** the first parameter to callbacks. 8212 ** 8213 ** ^The preupdate hook only fires for changes to real database tables; the 8214 ** preupdate hook is not invoked for changes to [virtual tables] or to 8215 ** system tables like sqlite_master or sqlite_stat1. 8216 ** 8217 ** ^The second parameter to the preupdate callback is a pointer to 8218 ** the [database connection] that registered the preupdate hook. 8219 ** ^The third parameter to the preupdate callback is one of the constants 8220 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8221 ** kind of update operation that is about to occur. 8222 ** ^(The fourth parameter to the preupdate callback is the name of the 8223 ** database within the database connection that is being modified. This 8224 ** will be "main" for the main database or "temp" for TEMP tables or 8225 ** the name given after the AS keyword in the [ATTACH] statement for attached 8226 ** databases.)^ 8227 ** ^The fifth parameter to the preupdate callback is the name of the 8228 ** table that is being modified. 8229 ** 8230 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 8231 ** parameter passed to the preupdate callback is the initial [rowid] of the 8232 ** row being modified or deleted. For an INSERT operation on a rowid table, 8233 ** or any operation on a WITHOUT ROWID table, the value of the sixth 8234 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8235 ** seventh parameter is the final rowid value of the row being inserted 8236 ** or updated. The value of the seventh parameter passed to the callback 8237 ** function is not defined for operations on WITHOUT ROWID tables, or for 8238 ** INSERT operations on rowid tables. 8239 ** 8240 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8241 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8242 ** provide additional information about a preupdate event. These routines 8243 ** may only be called from within a preupdate callback. Invoking any of 8244 ** these routines from outside of a preupdate callback or with a 8245 ** [database connection] pointer that is different from the one supplied 8246 ** to the preupdate callback results in undefined and probably undesirable 8247 ** behavior. 8248 ** 8249 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8250 ** in the row that is being inserted, updated, or deleted. 8251 ** 8252 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8253 ** a [protected sqlite3_value] that contains the value of the Nth column of 8254 ** the table row before it is updated. The N parameter must be between 0 8255 ** and one less than the number of columns or the behavior will be 8256 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8257 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8258 ** behavior is undefined. The [sqlite3_value] that P points to 8259 ** will be destroyed when the preupdate callback returns. 8260 ** 8261 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8262 ** a [protected sqlite3_value] that contains the value of the Nth column of 8263 ** the table row after it is updated. The N parameter must be between 0 8264 ** and one less than the number of columns or the behavior will be 8265 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8266 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8267 ** behavior is undefined. The [sqlite3_value] that P points to 8268 ** will be destroyed when the preupdate callback returns. 8269 ** 8270 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8271 ** callback was invoked as a result of a direct insert, update, or delete 8272 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 8273 ** triggers; or 2 for changes resulting from triggers called by top-level 8274 ** triggers; and so forth. 8275 ** 8276 ** See also: [sqlite3_update_hook()] 8277 */ 8278 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8279 SQLITE_API void *sqlite3_preupdate_hook( 8280 sqlite3 *db, 8281 void(*xPreUpdate)( 8282 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8283 sqlite3 *db, /* Database handle */ 8284 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8285 char const *zDb, /* Database name */ 8286 char const *zName, /* Table name */ 8287 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8288 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8289 ), 8290 void* 8291 ); 8292 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8293 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 8294 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 8295 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8296 #endif 8297 8298 /* 8299 ** CAPI3REF: Low-level system error code 8300 ** 8301 ** ^Attempt to return the underlying operating system error code or error 8302 ** number that caused the most recent I/O error or failure to open a file. 8303 ** The return value is OS-dependent. For example, on unix systems, after 8304 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8305 ** called to get back the underlying "errno" that caused the problem, such 8306 ** as ENOSPC, EAUTH, EISDIR, and so forth. 8307 */ 8308 SQLITE_API int sqlite3_system_errno(sqlite3*); 8309 8310 /* 8311 ** CAPI3REF: Database Snapshot 8312 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 8313 ** EXPERIMENTAL 8314 ** 8315 ** An instance of the snapshot object records the state of a [WAL mode] 8316 ** database for some specific point in history. 8317 ** 8318 ** In [WAL mode], multiple [database connections] that are open on the 8319 ** same database file can each be reading a different historical version 8320 ** of the database file. When a [database connection] begins a read 8321 ** transaction, that connection sees an unchanging copy of the database 8322 ** as it existed for the point in time when the transaction first started. 8323 ** Subsequent changes to the database from other connections are not seen 8324 ** by the reader until a new read transaction is started. 8325 ** 8326 ** The sqlite3_snapshot object records state information about an historical 8327 ** version of the database file so that it is possible to later open a new read 8328 ** transaction that sees that historical version of the database rather than 8329 ** the most recent version. 8330 ** 8331 ** The constructor for this object is [sqlite3_snapshot_get()]. The 8332 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8333 ** to an historical snapshot (if possible). The destructor for 8334 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8335 */ 8336 typedef struct sqlite3_snapshot { 8337 unsigned char hidden[48]; 8338 } sqlite3_snapshot; 8339 8340 /* 8341 ** CAPI3REF: Record A Database Snapshot 8342 ** EXPERIMENTAL 8343 ** 8344 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8345 ** new [sqlite3_snapshot] object that records the current state of 8346 ** schema S in database connection D. ^On success, the 8347 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8348 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8349 ** If there is not already a read-transaction open on schema S when 8350 ** this function is called, one is opened automatically. 8351 ** 8352 ** The following must be true for this function to succeed. If any of 8353 ** the following statements are false when sqlite3_snapshot_get() is 8354 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 8355 ** in this case. 8356 ** 8357 ** <ul> 8358 ** <li> The database handle must be in [autocommit mode]. 8359 ** 8360 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 8361 ** 8362 ** <li> There must not be a write transaction open on schema S of database 8363 ** connection D. 8364 ** 8365 ** <li> One or more transactions must have been written to the current wal 8366 ** file since it was created on disk (by any connection). This means 8367 ** that a snapshot cannot be taken on a wal mode database with no wal 8368 ** file immediately after it is first opened. At least one transaction 8369 ** must be written to it first. 8370 ** </ul> 8371 ** 8372 ** This function may also return SQLITE_NOMEM. If it is called with the 8373 ** database handle in autocommit mode but fails for some other reason, 8374 ** whether or not a read transaction is opened on schema S is undefined. 8375 ** 8376 ** The [sqlite3_snapshot] object returned from a successful call to 8377 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8378 ** to avoid a memory leak. 8379 ** 8380 ** The [sqlite3_snapshot_get()] interface is only available when the 8381 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8382 */ 8383 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8384 sqlite3 *db, 8385 const char *zSchema, 8386 sqlite3_snapshot **ppSnapshot 8387 ); 8388 8389 /* 8390 ** CAPI3REF: Start a read transaction on an historical snapshot 8391 ** EXPERIMENTAL 8392 ** 8393 ** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8394 ** read transaction for schema S of 8395 ** [database connection] D such that the read transaction 8396 ** refers to historical [snapshot] P, rather than the most 8397 ** recent change to the database. 8398 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8399 ** or an appropriate [error code] if it fails. 8400 ** 8401 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8402 ** the first operation following the [BEGIN] that takes the schema S 8403 ** out of [autocommit mode]. 8404 ** ^In other words, schema S must not currently be in 8405 ** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8406 ** database connection D must be out of [autocommit mode]. 8407 ** ^A [snapshot] will fail to open if it has been overwritten by a 8408 ** [checkpoint]. 8409 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8410 ** database connection D does not know that the database file for 8411 ** schema S is in [WAL mode]. A database connection might not know 8412 ** that the database file is in [WAL mode] if there has been no prior 8413 ** I/O on that database connection, or if the database entered [WAL mode] 8414 ** after the most recent I/O on the database connection.)^ 8415 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 8416 ** database connection in order to make it ready to use snapshots.) 8417 ** 8418 ** The [sqlite3_snapshot_open()] interface is only available when the 8419 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8420 */ 8421 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8422 sqlite3 *db, 8423 const char *zSchema, 8424 sqlite3_snapshot *pSnapshot 8425 ); 8426 8427 /* 8428 ** CAPI3REF: Destroy a snapshot 8429 ** EXPERIMENTAL 8430 ** 8431 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8432 ** The application must eventually free every [sqlite3_snapshot] object 8433 ** using this routine to avoid a memory leak. 8434 ** 8435 ** The [sqlite3_snapshot_free()] interface is only available when the 8436 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8437 */ 8438 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8439 8440 /* 8441 ** CAPI3REF: Compare the ages of two snapshot handles. 8442 ** EXPERIMENTAL 8443 ** 8444 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8445 ** of two valid snapshot handles. 8446 ** 8447 ** If the two snapshot handles are not associated with the same database 8448 ** file, the result of the comparison is undefined. 8449 ** 8450 ** Additionally, the result of the comparison is only valid if both of the 8451 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8452 ** last time the wal file was deleted. The wal file is deleted when the 8453 ** database is changed back to rollback mode or when the number of database 8454 ** clients drops to zero. If either snapshot handle was obtained before the 8455 ** wal file was last deleted, the value returned by this function 8456 ** is undefined. 8457 ** 8458 ** Otherwise, this API returns a negative value if P1 refers to an older 8459 ** snapshot than P2, zero if the two handles refer to the same database 8460 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 8461 */ 8462 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8463 sqlite3_snapshot *p1, 8464 sqlite3_snapshot *p2 8465 ); 8466 8467 /* 8468 ** CAPI3REF: Recover snapshots from a wal file 8469 ** EXPERIMENTAL 8470 ** 8471 ** If all connections disconnect from a database file but do not perform 8472 ** a checkpoint, the existing wal file is opened along with the database 8473 ** file the next time the database is opened. At this point it is only 8474 ** possible to successfully call sqlite3_snapshot_open() to open the most 8475 ** recent snapshot of the database (the one at the head of the wal file), 8476 ** even though the wal file may contain other valid snapshots for which 8477 ** clients have sqlite3_snapshot handles. 8478 ** 8479 ** This function attempts to scan the wal file associated with database zDb 8480 ** of database handle db and make all valid snapshots available to 8481 ** sqlite3_snapshot_open(). It is an error if there is already a read 8482 ** transaction open on the database, or if the database is not a wal mode 8483 ** database. 8484 ** 8485 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 8486 */ 8487 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 8488 8489 /* 8490 ** Undo the hack that converts floating point types to integer for 8491 ** builds on processors without floating point support. 8492 */ 8493 #ifdef SQLITE_OMIT_FLOATING_POINT 8494 # undef double 8495 #endif 8496 8497 #ifdef __cplusplus 8498 } /* End of the 'extern "C"' block */ 8499 #endif 8500 #endif /* SQLITE3_H */ 8501 8502 /******** Begin file sqlite3rtree.h *********/ 8503 /* 8504 ** 2010 August 30 8505 ** 8506 ** The author disclaims copyright to this source code. In place of 8507 ** a legal notice, here is a blessing: 8508 ** 8509 ** May you do good and not evil. 8510 ** May you find forgiveness for yourself and forgive others. 8511 ** May you share freely, never taking more than you give. 8512 ** 8513 ************************************************************************* 8514 */ 8515 8516 #ifndef _SQLITE3RTREE_H_ 8517 #define _SQLITE3RTREE_H_ 8518 8519 8520 #ifdef __cplusplus 8521 extern "C" { 8522 #endif 8523 8524 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8525 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8526 8527 /* The double-precision datatype used by RTree depends on the 8528 ** SQLITE_RTREE_INT_ONLY compile-time option. 8529 */ 8530 #ifdef SQLITE_RTREE_INT_ONLY 8531 typedef sqlite3_int64 sqlite3_rtree_dbl; 8532 #else 8533 typedef double sqlite3_rtree_dbl; 8534 #endif 8535 8536 /* 8537 ** Register a geometry callback named zGeom that can be used as part of an 8538 ** R-Tree geometry query as follows: 8539 ** 8540 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8541 */ 8542 SQLITE_API int sqlite3_rtree_geometry_callback( 8543 sqlite3 *db, 8544 const char *zGeom, 8545 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8546 void *pContext 8547 ); 8548 8549 8550 /* 8551 ** A pointer to a structure of the following type is passed as the first 8552 ** argument to callbacks registered using rtree_geometry_callback(). 8553 */ 8554 struct sqlite3_rtree_geometry { 8555 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8556 int nParam; /* Size of array aParam[] */ 8557 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8558 void *pUser; /* Callback implementation user data */ 8559 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8560 }; 8561 8562 /* 8563 ** Register a 2nd-generation geometry callback named zScore that can be 8564 ** used as part of an R-Tree geometry query as follows: 8565 ** 8566 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8567 */ 8568 SQLITE_API int sqlite3_rtree_query_callback( 8569 sqlite3 *db, 8570 const char *zQueryFunc, 8571 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8572 void *pContext, 8573 void (*xDestructor)(void*) 8574 ); 8575 8576 8577 /* 8578 ** A pointer to a structure of the following type is passed as the 8579 ** argument to scored geometry callback registered using 8580 ** sqlite3_rtree_query_callback(). 8581 ** 8582 ** Note that the first 5 fields of this structure are identical to 8583 ** sqlite3_rtree_geometry. This structure is a subclass of 8584 ** sqlite3_rtree_geometry. 8585 */ 8586 struct sqlite3_rtree_query_info { 8587 void *pContext; /* pContext from when function registered */ 8588 int nParam; /* Number of function parameters */ 8589 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8590 void *pUser; /* callback can use this, if desired */ 8591 void (*xDelUser)(void*); /* function to free pUser */ 8592 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8593 unsigned int *anQueue; /* Number of pending entries in the queue */ 8594 int nCoord; /* Number of coordinates */ 8595 int iLevel; /* Level of current node or entry */ 8596 int mxLevel; /* The largest iLevel value in the tree */ 8597 sqlite3_int64 iRowid; /* Rowid for current entry */ 8598 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8599 int eParentWithin; /* Visibility of parent node */ 8600 int eWithin; /* OUT: Visiblity */ 8601 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8602 /* The following fields are only available in 3.8.11 and later */ 8603 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8604 }; 8605 8606 /* 8607 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8608 */ 8609 #define NOT_WITHIN 0 /* Object completely outside of query region */ 8610 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8611 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 8612 8613 8614 #ifdef __cplusplus 8615 } /* end of the 'extern "C"' block */ 8616 #endif 8617 8618 #endif /* ifndef _SQLITE3RTREE_H_ */ 8619 8620 /******** End of sqlite3rtree.h *********/ 8621 /******** Begin file sqlite3session.h *********/ 8622 8623 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 8624 #define __SQLITESESSION_H_ 1 8625 8626 /* 8627 ** Make sure we can call this stuff from C++. 8628 */ 8629 #ifdef __cplusplus 8630 extern "C" { 8631 #endif 8632 8633 8634 /* 8635 ** CAPI3REF: Session Object Handle 8636 */ 8637 typedef struct sqlite3_session sqlite3_session; 8638 8639 /* 8640 ** CAPI3REF: Changeset Iterator Handle 8641 */ 8642 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 8643 8644 /* 8645 ** CAPI3REF: Create A New Session Object 8646 ** 8647 ** Create a new session object attached to database handle db. If successful, 8648 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 8649 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 8650 ** error code (e.g. SQLITE_NOMEM) is returned. 8651 ** 8652 ** It is possible to create multiple session objects attached to a single 8653 ** database handle. 8654 ** 8655 ** Session objects created using this function should be deleted using the 8656 ** [sqlite3session_delete()] function before the database handle that they 8657 ** are attached to is itself closed. If the database handle is closed before 8658 ** the session object is deleted, then the results of calling any session 8659 ** module function, including [sqlite3session_delete()] on the session object 8660 ** are undefined. 8661 ** 8662 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 8663 ** is not possible for an application to register a pre-update hook on a 8664 ** database handle that has one or more session objects attached. Nor is 8665 ** it possible to create a session object attached to a database handle for 8666 ** which a pre-update hook is already defined. The results of attempting 8667 ** either of these things are undefined. 8668 ** 8669 ** The session object will be used to create changesets for tables in 8670 ** database zDb, where zDb is either "main", or "temp", or the name of an 8671 ** attached database. It is not an error if database zDb is not attached 8672 ** to the database when the session object is created. 8673 */ 8674 SQLITE_API int sqlite3session_create( 8675 sqlite3 *db, /* Database handle */ 8676 const char *zDb, /* Name of db (e.g. "main") */ 8677 sqlite3_session **ppSession /* OUT: New session object */ 8678 ); 8679 8680 /* 8681 ** CAPI3REF: Delete A Session Object 8682 ** 8683 ** Delete a session object previously allocated using 8684 ** [sqlite3session_create()]. Once a session object has been deleted, the 8685 ** results of attempting to use pSession with any other session module 8686 ** function are undefined. 8687 ** 8688 ** Session objects must be deleted before the database handle to which they 8689 ** are attached is closed. Refer to the documentation for 8690 ** [sqlite3session_create()] for details. 8691 */ 8692 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 8693 8694 8695 /* 8696 ** CAPI3REF: Enable Or Disable A Session Object 8697 ** 8698 ** Enable or disable the recording of changes by a session object. When 8699 ** enabled, a session object records changes made to the database. When 8700 ** disabled - it does not. A newly created session object is enabled. 8701 ** Refer to the documentation for [sqlite3session_changeset()] for further 8702 ** details regarding how enabling and disabling a session object affects 8703 ** the eventual changesets. 8704 ** 8705 ** Passing zero to this function disables the session. Passing a value 8706 ** greater than zero enables it. Passing a value less than zero is a 8707 ** no-op, and may be used to query the current state of the session. 8708 ** 8709 ** The return value indicates the final state of the session object: 0 if 8710 ** the session is disabled, or 1 if it is enabled. 8711 */ 8712 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 8713 8714 /* 8715 ** CAPI3REF: Set Or Clear the Indirect Change Flag 8716 ** 8717 ** Each change recorded by a session object is marked as either direct or 8718 ** indirect. A change is marked as indirect if either: 8719 ** 8720 ** <ul> 8721 ** <li> The session object "indirect" flag is set when the change is 8722 ** made, or 8723 ** <li> The change is made by an SQL trigger or foreign key action 8724 ** instead of directly as a result of a users SQL statement. 8725 ** </ul> 8726 ** 8727 ** If a single row is affected by more than one operation within a session, 8728 ** then the change is considered indirect if all operations meet the criteria 8729 ** for an indirect change above, or direct otherwise. 8730 ** 8731 ** This function is used to set, clear or query the session object indirect 8732 ** flag. If the second argument passed to this function is zero, then the 8733 ** indirect flag is cleared. If it is greater than zero, the indirect flag 8734 ** is set. Passing a value less than zero does not modify the current value 8735 ** of the indirect flag, and may be used to query the current state of the 8736 ** indirect flag for the specified session object. 8737 ** 8738 ** The return value indicates the final state of the indirect flag: 0 if 8739 ** it is clear, or 1 if it is set. 8740 */ 8741 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 8742 8743 /* 8744 ** CAPI3REF: Attach A Table To A Session Object 8745 ** 8746 ** If argument zTab is not NULL, then it is the name of a table to attach 8747 ** to the session object passed as the first argument. All subsequent changes 8748 ** made to the table while the session object is enabled will be recorded. See 8749 ** documentation for [sqlite3session_changeset()] for further details. 8750 ** 8751 ** Or, if argument zTab is NULL, then changes are recorded for all tables 8752 ** in the database. If additional tables are added to the database (by 8753 ** executing "CREATE TABLE" statements) after this call is made, changes for 8754 ** the new tables are also recorded. 8755 ** 8756 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 8757 ** defined as part of their CREATE TABLE statement. It does not matter if the 8758 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 8759 ** KEY may consist of a single column, or may be a composite key. 8760 ** 8761 ** It is not an error if the named table does not exist in the database. Nor 8762 ** is it an error if the named table does not have a PRIMARY KEY. However, 8763 ** no changes will be recorded in either of these scenarios. 8764 ** 8765 ** Changes are not recorded for individual rows that have NULL values stored 8766 ** in one or more of their PRIMARY KEY columns. 8767 ** 8768 ** SQLITE_OK is returned if the call completes without error. Or, if an error 8769 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 8770 */ 8771 SQLITE_API int sqlite3session_attach( 8772 sqlite3_session *pSession, /* Session object */ 8773 const char *zTab /* Table name */ 8774 ); 8775 8776 /* 8777 ** CAPI3REF: Set a table filter on a Session Object. 8778 ** 8779 ** The second argument (xFilter) is the "filter callback". For changes to rows 8780 ** in tables that are not attached to the Session object, the filter is called 8781 ** to determine whether changes to the table's rows should be tracked or not. 8782 ** If xFilter returns 0, changes is not tracked. Note that once a table is 8783 ** attached, xFilter will not be called again. 8784 */ 8785 SQLITE_API void sqlite3session_table_filter( 8786 sqlite3_session *pSession, /* Session object */ 8787 int(*xFilter)( 8788 void *pCtx, /* Copy of third arg to _filter_table() */ 8789 const char *zTab /* Table name */ 8790 ), 8791 void *pCtx /* First argument passed to xFilter */ 8792 ); 8793 8794 /* 8795 ** CAPI3REF: Generate A Changeset From A Session Object 8796 ** 8797 ** Obtain a changeset containing changes to the tables attached to the 8798 ** session object passed as the first argument. If successful, 8799 ** set *ppChangeset to point to a buffer containing the changeset 8800 ** and *pnChangeset to the size of the changeset in bytes before returning 8801 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 8802 ** zero and return an SQLite error code. 8803 ** 8804 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 8805 ** each representing a change to a single row of an attached table. An INSERT 8806 ** change contains the values of each field of a new database row. A DELETE 8807 ** contains the original values of each field of a deleted database row. An 8808 ** UPDATE change contains the original values of each field of an updated 8809 ** database row along with the updated values for each updated non-primary-key 8810 ** column. It is not possible for an UPDATE change to represent a change that 8811 ** modifies the values of primary key columns. If such a change is made, it 8812 ** is represented in a changeset as a DELETE followed by an INSERT. 8813 ** 8814 ** Changes are not recorded for rows that have NULL values stored in one or 8815 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 8816 ** no corresponding change is present in the changesets returned by this 8817 ** function. If an existing row with one or more NULL values stored in 8818 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 8819 ** only an INSERT is appears in the changeset. Similarly, if an existing row 8820 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 8821 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 8822 ** DELETE change only. 8823 ** 8824 ** The contents of a changeset may be traversed using an iterator created 8825 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 8826 ** a database with a compatible schema using the [sqlite3changeset_apply()] 8827 ** API. 8828 ** 8829 ** Within a changeset generated by this function, all changes related to a 8830 ** single table are grouped together. In other words, when iterating through 8831 ** a changeset or when applying a changeset to a database, all changes related 8832 ** to a single table are processed before moving on to the next table. Tables 8833 ** are sorted in the same order in which they were attached (or auto-attached) 8834 ** to the sqlite3_session object. The order in which the changes related to 8835 ** a single table are stored is undefined. 8836 ** 8837 ** Following a successful call to this function, it is the responsibility of 8838 ** the caller to eventually free the buffer that *ppChangeset points to using 8839 ** [sqlite3_free()]. 8840 ** 8841 ** <h3>Changeset Generation</h3> 8842 ** 8843 ** Once a table has been attached to a session object, the session object 8844 ** records the primary key values of all new rows inserted into the table. 8845 ** It also records the original primary key and other column values of any 8846 ** deleted or updated rows. For each unique primary key value, data is only 8847 ** recorded once - the first time a row with said primary key is inserted, 8848 ** updated or deleted in the lifetime of the session. 8849 ** 8850 ** There is one exception to the previous paragraph: when a row is inserted, 8851 ** updated or deleted, if one or more of its primary key columns contain a 8852 ** NULL value, no record of the change is made. 8853 ** 8854 ** The session object therefore accumulates two types of records - those 8855 ** that consist of primary key values only (created when the user inserts 8856 ** a new record) and those that consist of the primary key values and the 8857 ** original values of other table columns (created when the users deletes 8858 ** or updates a record). 8859 ** 8860 ** When this function is called, the requested changeset is created using 8861 ** both the accumulated records and the current contents of the database 8862 ** file. Specifically: 8863 ** 8864 ** <ul> 8865 ** <li> For each record generated by an insert, the database is queried 8866 ** for a row with a matching primary key. If one is found, an INSERT 8867 ** change is added to the changeset. If no such row is found, no change 8868 ** is added to the changeset. 8869 ** 8870 ** <li> For each record generated by an update or delete, the database is 8871 ** queried for a row with a matching primary key. If such a row is 8872 ** found and one or more of the non-primary key fields have been 8873 ** modified from their original values, an UPDATE change is added to 8874 ** the changeset. Or, if no such row is found in the table, a DELETE 8875 ** change is added to the changeset. If there is a row with a matching 8876 ** primary key in the database, but all fields contain their original 8877 ** values, no change is added to the changeset. 8878 ** </ul> 8879 ** 8880 ** This means, amongst other things, that if a row is inserted and then later 8881 ** deleted while a session object is active, neither the insert nor the delete 8882 ** will be present in the changeset. Or if a row is deleted and then later a 8883 ** row with the same primary key values inserted while a session object is 8884 ** active, the resulting changeset will contain an UPDATE change instead of 8885 ** a DELETE and an INSERT. 8886 ** 8887 ** When a session object is disabled (see the [sqlite3session_enable()] API), 8888 ** it does not accumulate records when rows are inserted, updated or deleted. 8889 ** This may appear to have some counter-intuitive effects if a single row 8890 ** is written to more than once during a session. For example, if a row 8891 ** is inserted while a session object is enabled, then later deleted while 8892 ** the same session object is disabled, no INSERT record will appear in the 8893 ** changeset, even though the delete took place while the session was disabled. 8894 ** Or, if one field of a row is updated while a session is disabled, and 8895 ** another field of the same row is updated while the session is enabled, the 8896 ** resulting changeset will contain an UPDATE change that updates both fields. 8897 */ 8898 SQLITE_API int sqlite3session_changeset( 8899 sqlite3_session *pSession, /* Session object */ 8900 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 8901 void **ppChangeset /* OUT: Buffer containing changeset */ 8902 ); 8903 8904 /* 8905 ** CAPI3REF: Load The Difference Between Tables Into A Session 8906 ** 8907 ** If it is not already attached to the session object passed as the first 8908 ** argument, this function attaches table zTbl in the same manner as the 8909 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 8910 ** does not have a primary key, this function is a no-op (but does not return 8911 ** an error). 8912 ** 8913 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 8914 ** attached to the same database handle as the session object that contains 8915 ** a table compatible with the table attached to the session by this function. 8916 ** A table is considered compatible if it: 8917 ** 8918 ** <ul> 8919 ** <li> Has the same name, 8920 ** <li> Has the same set of columns declared in the same order, and 8921 ** <li> Has the same PRIMARY KEY definition. 8922 ** </ul> 8923 ** 8924 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 8925 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 8926 ** but no changes are added to the session object. As with other session 8927 ** APIs, tables without PRIMARY KEYs are simply ignored. 8928 ** 8929 ** This function adds a set of changes to the session object that could be 8930 ** used to update the table in database zFrom (call this the "from-table") 8931 ** so that its content is the same as the table attached to the session 8932 ** object (call this the "to-table"). Specifically: 8933 ** 8934 ** <ul> 8935 ** <li> For each row (primary key) that exists in the to-table but not in 8936 ** the from-table, an INSERT record is added to the session object. 8937 ** 8938 ** <li> For each row (primary key) that exists in the to-table but not in 8939 ** the from-table, a DELETE record is added to the session object. 8940 ** 8941 ** <li> For each row (primary key) that exists in both tables, but features 8942 ** different non-PK values in each, an UPDATE record is added to the 8943 ** session. 8944 ** </ul> 8945 ** 8946 ** To clarify, if this function is called and then a changeset constructed 8947 ** using [sqlite3session_changeset()], then after applying that changeset to 8948 ** database zFrom the contents of the two compatible tables would be 8949 ** identical. 8950 ** 8951 ** It an error if database zFrom does not exist or does not contain the 8952 ** required compatible table. 8953 ** 8954 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 8955 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 8956 ** may be set to point to a buffer containing an English language error 8957 ** message. It is the responsibility of the caller to free this buffer using 8958 ** sqlite3_free(). 8959 */ 8960 SQLITE_API int sqlite3session_diff( 8961 sqlite3_session *pSession, 8962 const char *zFromDb, 8963 const char *zTbl, 8964 char **pzErrMsg 8965 ); 8966 8967 8968 /* 8969 ** CAPI3REF: Generate A Patchset From A Session Object 8970 ** 8971 ** The differences between a patchset and a changeset are that: 8972 ** 8973 ** <ul> 8974 ** <li> DELETE records consist of the primary key fields only. The 8975 ** original values of other fields are omitted. 8976 ** <li> The original values of any modified fields are omitted from 8977 ** UPDATE records. 8978 ** </ul> 8979 ** 8980 ** A patchset blob may be used with up to date versions of all 8981 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 8982 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 8983 ** attempting to use a patchset blob with old versions of the 8984 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 8985 ** 8986 ** Because the non-primary key "old.*" fields are omitted, no 8987 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 8988 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 8989 ** in the same way as for changesets. 8990 ** 8991 ** Changes within a patchset are ordered in the same way as for changesets 8992 ** generated by the sqlite3session_changeset() function (i.e. all changes for 8993 ** a single table are grouped together, tables appear in the order in which 8994 ** they were attached to the session object). 8995 */ 8996 SQLITE_API int sqlite3session_patchset( 8997 sqlite3_session *pSession, /* Session object */ 8998 int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */ 8999 void **ppPatchset /* OUT: Buffer containing changeset */ 9000 ); 9001 9002 /* 9003 ** CAPI3REF: Test if a changeset has recorded any changes. 9004 ** 9005 ** Return non-zero if no changes to attached tables have been recorded by 9006 ** the session object passed as the first argument. Otherwise, if one or 9007 ** more changes have been recorded, return zero. 9008 ** 9009 ** Even if this function returns zero, it is possible that calling 9010 ** [sqlite3session_changeset()] on the session handle may still return a 9011 ** changeset that contains no changes. This can happen when a row in 9012 ** an attached table is modified and then later on the original values 9013 ** are restored. However, if this function returns non-zero, then it is 9014 ** guaranteed that a call to sqlite3session_changeset() will return a 9015 ** changeset containing zero changes. 9016 */ 9017 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 9018 9019 /* 9020 ** CAPI3REF: Create An Iterator To Traverse A Changeset 9021 ** 9022 ** Create an iterator used to iterate through the contents of a changeset. 9023 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 9024 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 9025 ** SQLite error code is returned. 9026 ** 9027 ** The following functions can be used to advance and query a changeset 9028 ** iterator created by this function: 9029 ** 9030 ** <ul> 9031 ** <li> [sqlite3changeset_next()] 9032 ** <li> [sqlite3changeset_op()] 9033 ** <li> [sqlite3changeset_new()] 9034 ** <li> [sqlite3changeset_old()] 9035 ** </ul> 9036 ** 9037 ** It is the responsibility of the caller to eventually destroy the iterator 9038 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 9039 ** changeset (pChangeset) must remain valid until after the iterator is 9040 ** destroyed. 9041 ** 9042 ** Assuming the changeset blob was created by one of the 9043 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9044 ** [sqlite3changeset_invert()] functions, all changes within the changeset 9045 ** that apply to a single table are grouped together. This means that when 9046 ** an application iterates through a changeset using an iterator created by 9047 ** this function, all changes that relate to a single table are visited 9048 ** consecutively. There is no chance that the iterator will visit a change 9049 ** the applies to table X, then one for table Y, and then later on visit 9050 ** another change for table X. 9051 */ 9052 SQLITE_API int sqlite3changeset_start( 9053 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9054 int nChangeset, /* Size of changeset blob in bytes */ 9055 void *pChangeset /* Pointer to blob containing changeset */ 9056 ); 9057 9058 9059 /* 9060 ** CAPI3REF: Advance A Changeset Iterator 9061 ** 9062 ** This function may only be used with iterators created by function 9063 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 9064 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 9065 ** is returned and the call has no effect. 9066 ** 9067 ** Immediately after an iterator is created by sqlite3changeset_start(), it 9068 ** does not point to any change in the changeset. Assuming the changeset 9069 ** is not empty, the first call to this function advances the iterator to 9070 ** point to the first change in the changeset. Each subsequent call advances 9071 ** the iterator to point to the next change in the changeset (if any). If 9072 ** no error occurs and the iterator points to a valid change after a call 9073 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 9074 ** Otherwise, if all changes in the changeset have already been visited, 9075 ** SQLITE_DONE is returned. 9076 ** 9077 ** If an error occurs, an SQLite error code is returned. Possible error 9078 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 9079 ** SQLITE_NOMEM. 9080 */ 9081 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 9082 9083 /* 9084 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 9085 ** 9086 ** The pIter argument passed to this function may either be an iterator 9087 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9088 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9089 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 9090 ** is not the case, this function returns [SQLITE_MISUSE]. 9091 ** 9092 ** If argument pzTab is not NULL, then *pzTab is set to point to a 9093 ** nul-terminated utf-8 encoded string containing the name of the table 9094 ** affected by the current change. The buffer remains valid until either 9095 ** sqlite3changeset_next() is called on the iterator or until the 9096 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 9097 ** set to the number of columns in the table affected by the change. If 9098 ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 9099 ** is an indirect change, or false (0) otherwise. See the documentation for 9100 ** [sqlite3session_indirect()] for a description of direct and indirect 9101 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 9102 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 9103 ** type of change that the iterator currently points to. 9104 ** 9105 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 9106 ** SQLite error code is returned. The values of the output variables may not 9107 ** be trusted in this case. 9108 */ 9109 SQLITE_API int sqlite3changeset_op( 9110 sqlite3_changeset_iter *pIter, /* Iterator object */ 9111 const char **pzTab, /* OUT: Pointer to table name */ 9112 int *pnCol, /* OUT: Number of columns in table */ 9113 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 9114 int *pbIndirect /* OUT: True for an 'indirect' change */ 9115 ); 9116 9117 /* 9118 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 9119 ** 9120 ** For each modified table, a changeset includes the following: 9121 ** 9122 ** <ul> 9123 ** <li> The number of columns in the table, and 9124 ** <li> Which of those columns make up the tables PRIMARY KEY. 9125 ** </ul> 9126 ** 9127 ** This function is used to find which columns comprise the PRIMARY KEY of 9128 ** the table modified by the change that iterator pIter currently points to. 9129 ** If successful, *pabPK is set to point to an array of nCol entries, where 9130 ** nCol is the number of columns in the table. Elements of *pabPK are set to 9131 ** 0x01 if the corresponding column is part of the tables primary key, or 9132 ** 0x00 if it is not. 9133 ** 9134 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 9135 ** in the table. 9136 ** 9137 ** If this function is called when the iterator does not point to a valid 9138 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9139 ** SQLITE_OK is returned and the output variables populated as described 9140 ** above. 9141 */ 9142 SQLITE_API int sqlite3changeset_pk( 9143 sqlite3_changeset_iter *pIter, /* Iterator object */ 9144 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9145 int *pnCol /* OUT: Number of entries in output array */ 9146 ); 9147 9148 /* 9149 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9150 ** 9151 ** The pIter argument passed to this function may either be an iterator 9152 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9153 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9154 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9155 ** Furthermore, it may only be called if the type of change that the iterator 9156 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9157 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9158 ** 9159 ** Argument iVal must be greater than or equal to 0, and less than the number 9160 ** of columns in the table affected by the current change. Otherwise, 9161 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9162 ** 9163 ** If successful, this function sets *ppValue to point to a protected 9164 ** sqlite3_value object containing the iVal'th value from the vector of 9165 ** original row values stored as part of the UPDATE or DELETE change and 9166 ** returns SQLITE_OK. The name of the function comes from the fact that this 9167 ** is similar to the "old.*" columns available to update or delete triggers. 9168 ** 9169 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9170 ** is returned and *ppValue is set to NULL. 9171 */ 9172 SQLITE_API int sqlite3changeset_old( 9173 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9174 int iVal, /* Column number */ 9175 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 9176 ); 9177 9178 /* 9179 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 9180 ** 9181 ** The pIter argument passed to this function may either be an iterator 9182 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9183 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9184 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9185 ** Furthermore, it may only be called if the type of change that the iterator 9186 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 9187 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9188 ** 9189 ** Argument iVal must be greater than or equal to 0, and less than the number 9190 ** of columns in the table affected by the current change. Otherwise, 9191 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9192 ** 9193 ** If successful, this function sets *ppValue to point to a protected 9194 ** sqlite3_value object containing the iVal'th value from the vector of 9195 ** new row values stored as part of the UPDATE or INSERT change and 9196 ** returns SQLITE_OK. If the change is an UPDATE and does not include 9197 ** a new value for the requested column, *ppValue is set to NULL and 9198 ** SQLITE_OK returned. The name of the function comes from the fact that 9199 ** this is similar to the "new.*" columns available to update or delete 9200 ** triggers. 9201 ** 9202 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9203 ** is returned and *ppValue is set to NULL. 9204 */ 9205 SQLITE_API int sqlite3changeset_new( 9206 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9207 int iVal, /* Column number */ 9208 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 9209 ); 9210 9211 /* 9212 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 9213 ** 9214 ** This function should only be used with iterator objects passed to a 9215 ** conflict-handler callback by [sqlite3changeset_apply()] with either 9216 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 9217 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 9218 ** is set to NULL. 9219 ** 9220 ** Argument iVal must be greater than or equal to 0, and less than the number 9221 ** of columns in the table affected by the current change. Otherwise, 9222 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9223 ** 9224 ** If successful, this function sets *ppValue to point to a protected 9225 ** sqlite3_value object containing the iVal'th value from the 9226 ** "conflicting row" associated with the current conflict-handler callback 9227 ** and returns SQLITE_OK. 9228 ** 9229 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9230 ** is returned and *ppValue is set to NULL. 9231 */ 9232 SQLITE_API int sqlite3changeset_conflict( 9233 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9234 int iVal, /* Column number */ 9235 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 9236 ); 9237 9238 /* 9239 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 9240 ** 9241 ** This function may only be called with an iterator passed to an 9242 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 9243 ** it sets the output variable to the total number of known foreign key 9244 ** violations in the destination database and returns SQLITE_OK. 9245 ** 9246 ** In all other cases this function returns SQLITE_MISUSE. 9247 */ 9248 SQLITE_API int sqlite3changeset_fk_conflicts( 9249 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9250 int *pnOut /* OUT: Number of FK violations */ 9251 ); 9252 9253 9254 /* 9255 ** CAPI3REF: Finalize A Changeset Iterator 9256 ** 9257 ** This function is used to finalize an iterator allocated with 9258 ** [sqlite3changeset_start()]. 9259 ** 9260 ** This function should only be called on iterators created using the 9261 ** [sqlite3changeset_start()] function. If an application calls this 9262 ** function with an iterator passed to a conflict-handler by 9263 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 9264 ** call has no effect. 9265 ** 9266 ** If an error was encountered within a call to an sqlite3changeset_xxx() 9267 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 9268 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 9269 ** to that error is returned by this function. Otherwise, SQLITE_OK is 9270 ** returned. This is to allow the following pattern (pseudo-code): 9271 ** 9272 ** sqlite3changeset_start(); 9273 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 9274 ** // Do something with change. 9275 ** } 9276 ** rc = sqlite3changeset_finalize(); 9277 ** if( rc!=SQLITE_OK ){ 9278 ** // An error has occurred 9279 ** } 9280 */ 9281 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 9282 9283 /* 9284 ** CAPI3REF: Invert A Changeset 9285 ** 9286 ** This function is used to "invert" a changeset object. Applying an inverted 9287 ** changeset to a database reverses the effects of applying the uninverted 9288 ** changeset. Specifically: 9289 ** 9290 ** <ul> 9291 ** <li> Each DELETE change is changed to an INSERT, and 9292 ** <li> Each INSERT change is changed to a DELETE, and 9293 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 9294 ** </ul> 9295 ** 9296 ** This function does not change the order in which changes appear within 9297 ** the changeset. It merely reverses the sense of each individual change. 9298 ** 9299 ** If successful, a pointer to a buffer containing the inverted changeset 9300 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 9301 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 9302 ** zeroed and an SQLite error code returned. 9303 ** 9304 ** It is the responsibility of the caller to eventually call sqlite3_free() 9305 ** on the *ppOut pointer to free the buffer allocation following a successful 9306 ** call to this function. 9307 ** 9308 ** WARNING/TODO: This function currently assumes that the input is a valid 9309 ** changeset. If it is not, the results are undefined. 9310 */ 9311 SQLITE_API int sqlite3changeset_invert( 9312 int nIn, const void *pIn, /* Input changeset */ 9313 int *pnOut, void **ppOut /* OUT: Inverse of input */ 9314 ); 9315 9316 /* 9317 ** CAPI3REF: Concatenate Two Changeset Objects 9318 ** 9319 ** This function is used to concatenate two changesets, A and B, into a 9320 ** single changeset. The result is a changeset equivalent to applying 9321 ** changeset A followed by changeset B. 9322 ** 9323 ** This function combines the two input changesets using an 9324 ** sqlite3_changegroup object. Calling it produces similar results as the 9325 ** following code fragment: 9326 ** 9327 ** sqlite3_changegroup *pGrp; 9328 ** rc = sqlite3_changegroup_new(&pGrp); 9329 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 9330 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 9331 ** if( rc==SQLITE_OK ){ 9332 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 9333 ** }else{ 9334 ** *ppOut = 0; 9335 ** *pnOut = 0; 9336 ** } 9337 ** 9338 ** Refer to the sqlite3_changegroup documentation below for details. 9339 */ 9340 SQLITE_API int sqlite3changeset_concat( 9341 int nA, /* Number of bytes in buffer pA */ 9342 void *pA, /* Pointer to buffer containing changeset A */ 9343 int nB, /* Number of bytes in buffer pB */ 9344 void *pB, /* Pointer to buffer containing changeset B */ 9345 int *pnOut, /* OUT: Number of bytes in output changeset */ 9346 void **ppOut /* OUT: Buffer containing output changeset */ 9347 ); 9348 9349 9350 /* 9351 ** CAPI3REF: Changegroup Handle 9352 */ 9353 typedef struct sqlite3_changegroup sqlite3_changegroup; 9354 9355 /* 9356 ** CAPI3REF: Create A New Changegroup Object 9357 ** 9358 ** An sqlite3_changegroup object is used to combine two or more changesets 9359 ** (or patchsets) into a single changeset (or patchset). A single changegroup 9360 ** object may combine changesets or patchsets, but not both. The output is 9361 ** always in the same format as the input. 9362 ** 9363 ** If successful, this function returns SQLITE_OK and populates (*pp) with 9364 ** a pointer to a new sqlite3_changegroup object before returning. The caller 9365 ** should eventually free the returned object using a call to 9366 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 9367 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 9368 ** 9369 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 9370 ** 9371 ** <ul> 9372 ** <li> It is created using a call to sqlite3changegroup_new(). 9373 ** 9374 ** <li> Zero or more changesets (or patchsets) are added to the object 9375 ** by calling sqlite3changegroup_add(). 9376 ** 9377 ** <li> The result of combining all input changesets together is obtained 9378 ** by the application via a call to sqlite3changegroup_output(). 9379 ** 9380 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 9381 ** </ul> 9382 ** 9383 ** Any number of calls to add() and output() may be made between the calls to 9384 ** new() and delete(), and in any order. 9385 ** 9386 ** As well as the regular sqlite3changegroup_add() and 9387 ** sqlite3changegroup_output() functions, also available are the streaming 9388 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 9389 */ 9390 int sqlite3changegroup_new(sqlite3_changegroup **pp); 9391 9392 /* 9393 ** CAPI3REF: Add A Changeset To A Changegroup 9394 ** 9395 ** Add all changes within the changeset (or patchset) in buffer pData (size 9396 ** nData bytes) to the changegroup. 9397 ** 9398 ** If the buffer contains a patchset, then all prior calls to this function 9399 ** on the same changegroup object must also have specified patchsets. Or, if 9400 ** the buffer contains a changeset, so must have the earlier calls to this 9401 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 9402 ** to the changegroup. 9403 ** 9404 ** Rows within the changeset and changegroup are identified by the values in 9405 ** their PRIMARY KEY columns. A change in the changeset is considered to 9406 ** apply to the same row as a change already present in the changegroup if 9407 ** the two rows have the same primary key. 9408 ** 9409 ** Changes to rows that do not already appear in the changegroup are 9410 ** simply copied into it. Or, if both the new changeset and the changegroup 9411 ** contain changes that apply to a single row, the final contents of the 9412 ** changegroup depends on the type of each change, as follows: 9413 ** 9414 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9415 ** <tr><th style="white-space:pre">Existing Change </th> 9416 ** <th style="white-space:pre">New Change </th> 9417 ** <th>Output Change 9418 ** <tr><td>INSERT <td>INSERT <td> 9419 ** The new change is ignored. This case does not occur if the new 9420 ** changeset was recorded immediately after the changesets already 9421 ** added to the changegroup. 9422 ** <tr><td>INSERT <td>UPDATE <td> 9423 ** The INSERT change remains in the changegroup. The values in the 9424 ** INSERT change are modified as if the row was inserted by the 9425 ** existing change and then updated according to the new change. 9426 ** <tr><td>INSERT <td>DELETE <td> 9427 ** The existing INSERT is removed from the changegroup. The DELETE is 9428 ** not added. 9429 ** <tr><td>UPDATE <td>INSERT <td> 9430 ** The new change is ignored. This case does not occur if the new 9431 ** changeset was recorded immediately after the changesets already 9432 ** added to the changegroup. 9433 ** <tr><td>UPDATE <td>UPDATE <td> 9434 ** The existing UPDATE remains within the changegroup. It is amended 9435 ** so that the accompanying values are as if the row was updated once 9436 ** by the existing change and then again by the new change. 9437 ** <tr><td>UPDATE <td>DELETE <td> 9438 ** The existing UPDATE is replaced by the new DELETE within the 9439 ** changegroup. 9440 ** <tr><td>DELETE <td>INSERT <td> 9441 ** If one or more of the column values in the row inserted by the 9442 ** new change differ from those in the row deleted by the existing 9443 ** change, the existing DELETE is replaced by an UPDATE within the 9444 ** changegroup. Otherwise, if the inserted row is exactly the same 9445 ** as the deleted row, the existing DELETE is simply discarded. 9446 ** <tr><td>DELETE <td>UPDATE <td> 9447 ** The new change is ignored. This case does not occur if the new 9448 ** changeset was recorded immediately after the changesets already 9449 ** added to the changegroup. 9450 ** <tr><td>DELETE <td>DELETE <td> 9451 ** The new change is ignored. This case does not occur if the new 9452 ** changeset was recorded immediately after the changesets already 9453 ** added to the changegroup. 9454 ** </table> 9455 ** 9456 ** If the new changeset contains changes to a table that is already present 9457 ** in the changegroup, then the number of columns and the position of the 9458 ** primary key columns for the table must be consistent. If this is not the 9459 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 9460 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 9461 ** returned. Or, if an out-of-memory condition occurs during processing, this 9462 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 9463 ** final contents of the changegroup is undefined. 9464 ** 9465 ** If no error occurs, SQLITE_OK is returned. 9466 */ 9467 int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 9468 9469 /* 9470 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 9471 ** 9472 ** Obtain a buffer containing a changeset (or patchset) representing the 9473 ** current contents of the changegroup. If the inputs to the changegroup 9474 ** were themselves changesets, the output is a changeset. Or, if the 9475 ** inputs were patchsets, the output is also a patchset. 9476 ** 9477 ** As with the output of the sqlite3session_changeset() and 9478 ** sqlite3session_patchset() functions, all changes related to a single 9479 ** table are grouped together in the output of this function. Tables appear 9480 ** in the same order as for the very first changeset added to the changegroup. 9481 ** If the second or subsequent changesets added to the changegroup contain 9482 ** changes for tables that do not appear in the first changeset, they are 9483 ** appended onto the end of the output changeset, again in the order in 9484 ** which they are first encountered. 9485 ** 9486 ** If an error occurs, an SQLite error code is returned and the output 9487 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 9488 ** is returned and the output variables are set to the size of and a 9489 ** pointer to the output buffer, respectively. In this case it is the 9490 ** responsibility of the caller to eventually free the buffer using a 9491 ** call to sqlite3_free(). 9492 */ 9493 int sqlite3changegroup_output( 9494 sqlite3_changegroup*, 9495 int *pnData, /* OUT: Size of output buffer in bytes */ 9496 void **ppData /* OUT: Pointer to output buffer */ 9497 ); 9498 9499 /* 9500 ** CAPI3REF: Delete A Changegroup Object 9501 */ 9502 void sqlite3changegroup_delete(sqlite3_changegroup*); 9503 9504 /* 9505 ** CAPI3REF: Apply A Changeset To A Database 9506 ** 9507 ** Apply a changeset to a database. This function attempts to update the 9508 ** "main" database attached to handle db with the changes found in the 9509 ** changeset passed via the second and third arguments. 9510 ** 9511 ** The fourth argument (xFilter) passed to this function is the "filter 9512 ** callback". If it is not NULL, then for each table affected by at least one 9513 ** change in the changeset, the filter callback is invoked with 9514 ** the table name as the second argument, and a copy of the context pointer 9515 ** passed as the sixth argument to this function as the first. If the "filter 9516 ** callback" returns zero, then no attempt is made to apply any changes to 9517 ** the table. Otherwise, if the return value is non-zero or the xFilter 9518 ** argument to this function is NULL, all changes related to the table are 9519 ** attempted. 9520 ** 9521 ** For each table that is not excluded by the filter callback, this function 9522 ** tests that the target database contains a compatible table. A table is 9523 ** considered compatible if all of the following are true: 9524 ** 9525 ** <ul> 9526 ** <li> The table has the same name as the name recorded in the 9527 ** changeset, and 9528 ** <li> The table has at least as many columns as recorded in the 9529 ** changeset, and 9530 ** <li> The table has primary key columns in the same position as 9531 ** recorded in the changeset. 9532 ** </ul> 9533 ** 9534 ** If there is no compatible table, it is not an error, but none of the 9535 ** changes associated with the table are applied. A warning message is issued 9536 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 9537 ** one such warning is issued for each table in the changeset. 9538 ** 9539 ** For each change for which there is a compatible table, an attempt is made 9540 ** to modify the table contents according to the UPDATE, INSERT or DELETE 9541 ** change. If a change cannot be applied cleanly, the conflict handler 9542 ** function passed as the fifth argument to sqlite3changeset_apply() may be 9543 ** invoked. A description of exactly when the conflict handler is invoked for 9544 ** each type of change is below. 9545 ** 9546 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 9547 ** of passing anything other than a valid function pointer as the xConflict 9548 ** argument are undefined. 9549 ** 9550 ** Each time the conflict handler function is invoked, it must return one 9551 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 9552 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 9553 ** if the second argument passed to the conflict handler is either 9554 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 9555 ** returns an illegal value, any changes already made are rolled back and 9556 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 9557 ** actions are taken by sqlite3changeset_apply() depending on the value 9558 ** returned by each invocation of the conflict-handler function. Refer to 9559 ** the documentation for the three 9560 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 9561 ** 9562 ** <dl> 9563 ** <dt>DELETE Changes<dd> 9564 ** For each DELETE change, this function checks if the target database 9565 ** contains a row with the same primary key value (or values) as the 9566 ** original row values stored in the changeset. If it does, and the values 9567 ** stored in all non-primary key columns also match the values stored in 9568 ** the changeset the row is deleted from the target database. 9569 ** 9570 ** If a row with matching primary key values is found, but one or more of 9571 ** the non-primary key fields contains a value different from the original 9572 ** row value stored in the changeset, the conflict-handler function is 9573 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 9574 ** database table has more columns than are recorded in the changeset, 9575 ** only the values of those non-primary key fields are compared against 9576 ** the current database contents - any trailing database table columns 9577 ** are ignored. 9578 ** 9579 ** If no row with matching primary key values is found in the database, 9580 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9581 ** passed as the second argument. 9582 ** 9583 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 9584 ** (which can only happen if a foreign key constraint is violated), the 9585 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 9586 ** passed as the second argument. This includes the case where the DELETE 9587 ** operation is attempted because an earlier call to the conflict handler 9588 ** function returned [SQLITE_CHANGESET_REPLACE]. 9589 ** 9590 ** <dt>INSERT Changes<dd> 9591 ** For each INSERT change, an attempt is made to insert the new row into 9592 ** the database. If the changeset row contains fewer fields than the 9593 ** database table, the trailing fields are populated with their default 9594 ** values. 9595 ** 9596 ** If the attempt to insert the row fails because the database already 9597 ** contains a row with the same primary key values, the conflict handler 9598 ** function is invoked with the second argument set to 9599 ** [SQLITE_CHANGESET_CONFLICT]. 9600 ** 9601 ** If the attempt to insert the row fails because of some other constraint 9602 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 9603 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 9604 ** This includes the case where the INSERT operation is re-attempted because 9605 ** an earlier call to the conflict handler function returned 9606 ** [SQLITE_CHANGESET_REPLACE]. 9607 ** 9608 ** <dt>UPDATE Changes<dd> 9609 ** For each UPDATE change, this function checks if the target database 9610 ** contains a row with the same primary key value (or values) as the 9611 ** original row values stored in the changeset. If it does, and the values 9612 ** stored in all modified non-primary key columns also match the values 9613 ** stored in the changeset the row is updated within the target database. 9614 ** 9615 ** If a row with matching primary key values is found, but one or more of 9616 ** the modified non-primary key fields contains a value different from an 9617 ** original row value stored in the changeset, the conflict-handler function 9618 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 9619 ** UPDATE changes only contain values for non-primary key fields that are 9620 ** to be modified, only those fields need to match the original values to 9621 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 9622 ** 9623 ** If no row with matching primary key values is found in the database, 9624 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9625 ** passed as the second argument. 9626 ** 9627 ** If the UPDATE operation is attempted, but SQLite returns 9628 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 9629 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 9630 ** This includes the case where the UPDATE operation is attempted after 9631 ** an earlier call to the conflict handler function returned 9632 ** [SQLITE_CHANGESET_REPLACE]. 9633 ** </dl> 9634 ** 9635 ** It is safe to execute SQL statements, including those that write to the 9636 ** table that the callback related to, from within the xConflict callback. 9637 ** This can be used to further customize the applications conflict 9638 ** resolution strategy. 9639 ** 9640 ** All changes made by this function are enclosed in a savepoint transaction. 9641 ** If any other error (aside from a constraint failure when attempting to 9642 ** write to the target database) occurs, then the savepoint transaction is 9643 ** rolled back, restoring the target database to its original state, and an 9644 ** SQLite error code returned. 9645 */ 9646 SQLITE_API int sqlite3changeset_apply( 9647 sqlite3 *db, /* Apply change to "main" db of this handle */ 9648 int nChangeset, /* Size of changeset in bytes */ 9649 void *pChangeset, /* Changeset blob */ 9650 int(*xFilter)( 9651 void *pCtx, /* Copy of sixth arg to _apply() */ 9652 const char *zTab /* Table name */ 9653 ), 9654 int(*xConflict)( 9655 void *pCtx, /* Copy of sixth arg to _apply() */ 9656 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9657 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9658 ), 9659 void *pCtx /* First argument passed to xConflict */ 9660 ); 9661 9662 /* 9663 ** CAPI3REF: Constants Passed To The Conflict Handler 9664 ** 9665 ** Values that may be passed as the second argument to a conflict-handler. 9666 ** 9667 ** <dl> 9668 ** <dt>SQLITE_CHANGESET_DATA<dd> 9669 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 9670 ** when processing a DELETE or UPDATE change if a row with the required 9671 ** PRIMARY KEY fields is present in the database, but one or more other 9672 ** (non primary-key) fields modified by the update do not contain the 9673 ** expected "before" values. 9674 ** 9675 ** The conflicting row, in this case, is the database row with the matching 9676 ** primary key. 9677 ** 9678 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 9679 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 9680 ** argument when processing a DELETE or UPDATE change if a row with the 9681 ** required PRIMARY KEY fields is not present in the database. 9682 ** 9683 ** There is no conflicting row in this case. The results of invoking the 9684 ** sqlite3changeset_conflict() API are undefined. 9685 ** 9686 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 9687 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 9688 ** handler while processing an INSERT change if the operation would result 9689 ** in duplicate primary key values. 9690 ** 9691 ** The conflicting row in this case is the database row with the matching 9692 ** primary key. 9693 ** 9694 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 9695 ** If foreign key handling is enabled, and applying a changeset leaves the 9696 ** database in a state containing foreign key violations, the conflict 9697 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 9698 ** exactly once before the changeset is committed. If the conflict handler 9699 ** returns CHANGESET_OMIT, the changes, including those that caused the 9700 ** foreign key constraint violation, are committed. Or, if it returns 9701 ** CHANGESET_ABORT, the changeset is rolled back. 9702 ** 9703 ** No current or conflicting row information is provided. The only function 9704 ** it is possible to call on the supplied sqlite3_changeset_iter handle 9705 ** is sqlite3changeset_fk_conflicts(). 9706 ** 9707 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 9708 ** If any other constraint violation occurs while applying a change (i.e. 9709 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 9710 ** invoked with CHANGESET_CONSTRAINT as the second argument. 9711 ** 9712 ** There is no conflicting row in this case. The results of invoking the 9713 ** sqlite3changeset_conflict() API are undefined. 9714 ** 9715 ** </dl> 9716 */ 9717 #define SQLITE_CHANGESET_DATA 1 9718 #define SQLITE_CHANGESET_NOTFOUND 2 9719 #define SQLITE_CHANGESET_CONFLICT 3 9720 #define SQLITE_CHANGESET_CONSTRAINT 4 9721 #define SQLITE_CHANGESET_FOREIGN_KEY 5 9722 9723 /* 9724 ** CAPI3REF: Constants Returned By The Conflict Handler 9725 ** 9726 ** A conflict handler callback must return one of the following three values. 9727 ** 9728 ** <dl> 9729 ** <dt>SQLITE_CHANGESET_OMIT<dd> 9730 ** If a conflict handler returns this value no special action is taken. The 9731 ** change that caused the conflict is not applied. The session module 9732 ** continues to the next change in the changeset. 9733 ** 9734 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 9735 ** This value may only be returned if the second argument to the conflict 9736 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 9737 ** is not the case, any changes applied so far are rolled back and the 9738 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 9739 ** 9740 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 9741 ** handler, then the conflicting row is either updated or deleted, depending 9742 ** on the type of change. 9743 ** 9744 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 9745 ** handler, then the conflicting row is removed from the database and a 9746 ** second attempt to apply the change is made. If this second attempt fails, 9747 ** the original row is restored to the database before continuing. 9748 ** 9749 ** <dt>SQLITE_CHANGESET_ABORT<dd> 9750 ** If this value is returned, any changes applied so far are rolled back 9751 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 9752 ** </dl> 9753 */ 9754 #define SQLITE_CHANGESET_OMIT 0 9755 #define SQLITE_CHANGESET_REPLACE 1 9756 #define SQLITE_CHANGESET_ABORT 2 9757 9758 /* 9759 ** CAPI3REF: Streaming Versions of API functions. 9760 ** 9761 ** The six streaming API xxx_strm() functions serve similar purposes to the 9762 ** corresponding non-streaming API functions: 9763 ** 9764 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9765 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 9766 ** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply] 9767 ** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat] 9768 ** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert] 9769 ** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start] 9770 ** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset] 9771 ** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset] 9772 ** </table> 9773 ** 9774 ** Non-streaming functions that accept changesets (or patchsets) as input 9775 ** require that the entire changeset be stored in a single buffer in memory. 9776 ** Similarly, those that return a changeset or patchset do so by returning 9777 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 9778 ** Normally this is convenient. However, if an application running in a 9779 ** low-memory environment is required to handle very large changesets, the 9780 ** large contiguous memory allocations required can become onerous. 9781 ** 9782 ** In order to avoid this problem, instead of a single large buffer, input 9783 ** is passed to a streaming API functions by way of a callback function that 9784 ** the sessions module invokes to incrementally request input data as it is 9785 ** required. In all cases, a pair of API function parameters such as 9786 ** 9787 ** <pre> 9788 ** int nChangeset, 9789 ** void *pChangeset, 9790 ** </pre> 9791 ** 9792 ** Is replaced by: 9793 ** 9794 ** <pre> 9795 ** int (*xInput)(void *pIn, void *pData, int *pnData), 9796 ** void *pIn, 9797 ** </pre> 9798 ** 9799 ** Each time the xInput callback is invoked by the sessions module, the first 9800 ** argument passed is a copy of the supplied pIn context pointer. The second 9801 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 9802 ** error occurs the xInput method should copy up to (*pnData) bytes of data 9803 ** into the buffer and set (*pnData) to the actual number of bytes copied 9804 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 9805 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 9806 ** error code should be returned. In all cases, if an xInput callback returns 9807 ** an error, all processing is abandoned and the streaming API function 9808 ** returns a copy of the error code to the caller. 9809 ** 9810 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 9811 ** invoked by the sessions module at any point during the lifetime of the 9812 ** iterator. If such an xInput callback returns an error, the iterator enters 9813 ** an error state, whereby all subsequent calls to iterator functions 9814 ** immediately fail with the same error code as returned by xInput. 9815 ** 9816 ** Similarly, streaming API functions that return changesets (or patchsets) 9817 ** return them in chunks by way of a callback function instead of via a 9818 ** pointer to a single large buffer. In this case, a pair of parameters such 9819 ** as: 9820 ** 9821 ** <pre> 9822 ** int *pnChangeset, 9823 ** void **ppChangeset, 9824 ** </pre> 9825 ** 9826 ** Is replaced by: 9827 ** 9828 ** <pre> 9829 ** int (*xOutput)(void *pOut, const void *pData, int nData), 9830 ** void *pOut 9831 ** </pre> 9832 ** 9833 ** The xOutput callback is invoked zero or more times to return data to 9834 ** the application. The first parameter passed to each call is a copy of the 9835 ** pOut pointer supplied by the application. The second parameter, pData, 9836 ** points to a buffer nData bytes in size containing the chunk of output 9837 ** data being returned. If the xOutput callback successfully processes the 9838 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 9839 ** it should return some other SQLite error code. In this case processing 9840 ** is immediately abandoned and the streaming API function returns a copy 9841 ** of the xOutput error code to the application. 9842 ** 9843 ** The sessions module never invokes an xOutput callback with the third 9844 ** parameter set to a value less than or equal to zero. Other than this, 9845 ** no guarantees are made as to the size of the chunks of data returned. 9846 */ 9847 SQLITE_API int sqlite3changeset_apply_strm( 9848 sqlite3 *db, /* Apply change to "main" db of this handle */ 9849 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 9850 void *pIn, /* First arg for xInput */ 9851 int(*xFilter)( 9852 void *pCtx, /* Copy of sixth arg to _apply() */ 9853 const char *zTab /* Table name */ 9854 ), 9855 int(*xConflict)( 9856 void *pCtx, /* Copy of sixth arg to _apply() */ 9857 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9858 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9859 ), 9860 void *pCtx /* First argument passed to xConflict */ 9861 ); 9862 SQLITE_API int sqlite3changeset_concat_strm( 9863 int (*xInputA)(void *pIn, void *pData, int *pnData), 9864 void *pInA, 9865 int (*xInputB)(void *pIn, void *pData, int *pnData), 9866 void *pInB, 9867 int (*xOutput)(void *pOut, const void *pData, int nData), 9868 void *pOut 9869 ); 9870 SQLITE_API int sqlite3changeset_invert_strm( 9871 int (*xInput)(void *pIn, void *pData, int *pnData), 9872 void *pIn, 9873 int (*xOutput)(void *pOut, const void *pData, int nData), 9874 void *pOut 9875 ); 9876 SQLITE_API int sqlite3changeset_start_strm( 9877 sqlite3_changeset_iter **pp, 9878 int (*xInput)(void *pIn, void *pData, int *pnData), 9879 void *pIn 9880 ); 9881 SQLITE_API int sqlite3session_changeset_strm( 9882 sqlite3_session *pSession, 9883 int (*xOutput)(void *pOut, const void *pData, int nData), 9884 void *pOut 9885 ); 9886 SQLITE_API int sqlite3session_patchset_strm( 9887 sqlite3_session *pSession, 9888 int (*xOutput)(void *pOut, const void *pData, int nData), 9889 void *pOut 9890 ); 9891 int sqlite3changegroup_add_strm(sqlite3_changegroup*, 9892 int (*xInput)(void *pIn, void *pData, int *pnData), 9893 void *pIn 9894 ); 9895 int sqlite3changegroup_output_strm(sqlite3_changegroup*, 9896 int (*xOutput)(void *pOut, const void *pData, int nData), 9897 void *pOut 9898 ); 9899 9900 9901 /* 9902 ** Make sure we can call this stuff from C++. 9903 */ 9904 #ifdef __cplusplus 9905 } 9906 #endif 9907 9908 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 9909 9910 /******** End of sqlite3session.h *********/ 9911 /******** Begin file fts5.h *********/ 9912 /* 9913 ** 2014 May 31 9914 ** 9915 ** The author disclaims copyright to this source code. In place of 9916 ** a legal notice, here is a blessing: 9917 ** 9918 ** May you do good and not evil. 9919 ** May you find forgiveness for yourself and forgive others. 9920 ** May you share freely, never taking more than you give. 9921 ** 9922 ****************************************************************************** 9923 ** 9924 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 9925 ** FTS5 may be extended with: 9926 ** 9927 ** * custom tokenizers, and 9928 ** * custom auxiliary functions. 9929 */ 9930 9931 9932 #ifndef _FTS5_H 9933 #define _FTS5_H 9934 9935 9936 #ifdef __cplusplus 9937 extern "C" { 9938 #endif 9939 9940 /************************************************************************* 9941 ** CUSTOM AUXILIARY FUNCTIONS 9942 ** 9943 ** Virtual table implementations may overload SQL functions by implementing 9944 ** the sqlite3_module.xFindFunction() method. 9945 */ 9946 9947 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 9948 typedef struct Fts5Context Fts5Context; 9949 typedef struct Fts5PhraseIter Fts5PhraseIter; 9950 9951 typedef void (*fts5_extension_function)( 9952 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 9953 Fts5Context *pFts, /* First arg to pass to pApi functions */ 9954 sqlite3_context *pCtx, /* Context for returning result/error */ 9955 int nVal, /* Number of values in apVal[] array */ 9956 sqlite3_value **apVal /* Array of trailing arguments */ 9957 ); 9958 9959 struct Fts5PhraseIter { 9960 const unsigned char *a; 9961 const unsigned char *b; 9962 }; 9963 9964 /* 9965 ** EXTENSION API FUNCTIONS 9966 ** 9967 ** xUserData(pFts): 9968 ** Return a copy of the context pointer the extension function was 9969 ** registered with. 9970 ** 9971 ** xColumnTotalSize(pFts, iCol, pnToken): 9972 ** If parameter iCol is less than zero, set output variable *pnToken 9973 ** to the total number of tokens in the FTS5 table. Or, if iCol is 9974 ** non-negative but less than the number of columns in the table, return 9975 ** the total number of tokens in column iCol, considering all rows in 9976 ** the FTS5 table. 9977 ** 9978 ** If parameter iCol is greater than or equal to the number of columns 9979 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9980 ** an OOM condition or IO error), an appropriate SQLite error code is 9981 ** returned. 9982 ** 9983 ** xColumnCount(pFts): 9984 ** Return the number of columns in the table. 9985 ** 9986 ** xColumnSize(pFts, iCol, pnToken): 9987 ** If parameter iCol is less than zero, set output variable *pnToken 9988 ** to the total number of tokens in the current row. Or, if iCol is 9989 ** non-negative but less than the number of columns in the table, set 9990 ** *pnToken to the number of tokens in column iCol of the current row. 9991 ** 9992 ** If parameter iCol is greater than or equal to the number of columns 9993 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 9994 ** an OOM condition or IO error), an appropriate SQLite error code is 9995 ** returned. 9996 ** 9997 ** This function may be quite inefficient if used with an FTS5 table 9998 ** created with the "columnsize=0" option. 9999 ** 10000 ** xColumnText: 10001 ** This function attempts to retrieve the text of column iCol of the 10002 ** current document. If successful, (*pz) is set to point to a buffer 10003 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 10004 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 10005 ** if an error occurs, an SQLite error code is returned and the final values 10006 ** of (*pz) and (*pn) are undefined. 10007 ** 10008 ** xPhraseCount: 10009 ** Returns the number of phrases in the current query expression. 10010 ** 10011 ** xPhraseSize: 10012 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 10013 ** are numbered starting from zero. 10014 ** 10015 ** xInstCount: 10016 ** Set *pnInst to the total number of occurrences of all phrases within 10017 ** the query within the current row. Return SQLITE_OK if successful, or 10018 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 10019 ** 10020 ** This API can be quite slow if used with an FTS5 table created with the 10021 ** "detail=none" or "detail=column" option. If the FTS5 table is created 10022 ** with either "detail=none" or "detail=column" and "content=" option 10023 ** (i.e. if it is a contentless table), then this API always returns 0. 10024 ** 10025 ** xInst: 10026 ** Query for the details of phrase match iIdx within the current row. 10027 ** Phrase matches are numbered starting from zero, so the iIdx argument 10028 ** should be greater than or equal to zero and smaller than the value 10029 ** output by xInstCount(). 10030 ** 10031 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 10032 ** to the column in which it occurs and *piOff the token offset of the 10033 ** first token of the phrase. The exception is if the table was created 10034 ** with the offsets=0 option specified. In this case *piOff is always 10035 ** set to -1. 10036 ** 10037 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 10038 ** if an error occurs. 10039 ** 10040 ** This API can be quite slow if used with an FTS5 table created with the 10041 ** "detail=none" or "detail=column" option. 10042 ** 10043 ** xRowid: 10044 ** Returns the rowid of the current row. 10045 ** 10046 ** xTokenize: 10047 ** Tokenize text using the tokenizer belonging to the FTS5 table. 10048 ** 10049 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 10050 ** This API function is used to query the FTS table for phrase iPhrase 10051 ** of the current query. Specifically, a query equivalent to: 10052 ** 10053 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 10054 ** 10055 ** with $p set to a phrase equivalent to the phrase iPhrase of the 10056 ** current query is executed. Any column filter that applies to 10057 ** phrase iPhrase of the current query is included in $p. For each 10058 ** row visited, the callback function passed as the fourth argument 10059 ** is invoked. The context and API objects passed to the callback 10060 ** function may be used to access the properties of each matched row. 10061 ** Invoking Api.xUserData() returns a copy of the pointer passed as 10062 ** the third argument to pUserData. 10063 ** 10064 ** If the callback function returns any value other than SQLITE_OK, the 10065 ** query is abandoned and the xQueryPhrase function returns immediately. 10066 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 10067 ** Otherwise, the error code is propagated upwards. 10068 ** 10069 ** If the query runs to completion without incident, SQLITE_OK is returned. 10070 ** Or, if some error occurs before the query completes or is aborted by 10071 ** the callback, an SQLite error code is returned. 10072 ** 10073 ** 10074 ** xSetAuxdata(pFts5, pAux, xDelete) 10075 ** 10076 ** Save the pointer passed as the second argument as the extension functions 10077 ** "auxiliary data". The pointer may then be retrieved by the current or any 10078 ** future invocation of the same fts5 extension function made as part of 10079 ** of the same MATCH query using the xGetAuxdata() API. 10080 ** 10081 ** Each extension function is allocated a single auxiliary data slot for 10082 ** each FTS query (MATCH expression). If the extension function is invoked 10083 ** more than once for a single FTS query, then all invocations share a 10084 ** single auxiliary data context. 10085 ** 10086 ** If there is already an auxiliary data pointer when this function is 10087 ** invoked, then it is replaced by the new pointer. If an xDelete callback 10088 ** was specified along with the original pointer, it is invoked at this 10089 ** point. 10090 ** 10091 ** The xDelete callback, if one is specified, is also invoked on the 10092 ** auxiliary data pointer after the FTS5 query has finished. 10093 ** 10094 ** If an error (e.g. an OOM condition) occurs within this function, an 10095 ** the auxiliary data is set to NULL and an error code returned. If the 10096 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 10097 ** pointer before returning. 10098 ** 10099 ** 10100 ** xGetAuxdata(pFts5, bClear) 10101 ** 10102 ** Returns the current auxiliary data pointer for the fts5 extension 10103 ** function. See the xSetAuxdata() method for details. 10104 ** 10105 ** If the bClear argument is non-zero, then the auxiliary data is cleared 10106 ** (set to NULL) before this function returns. In this case the xDelete, 10107 ** if any, is not invoked. 10108 ** 10109 ** 10110 ** xRowCount(pFts5, pnRow) 10111 ** 10112 ** This function is used to retrieve the total number of rows in the table. 10113 ** In other words, the same value that would be returned by: 10114 ** 10115 ** SELECT count(*) FROM ftstable; 10116 ** 10117 ** xPhraseFirst() 10118 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 10119 ** method, to iterate through all instances of a single query phrase within 10120 ** the current row. This is the same information as is accessible via the 10121 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 10122 ** to use, this API may be faster under some circumstances. To iterate 10123 ** through instances of phrase iPhrase, use the following code: 10124 ** 10125 ** Fts5PhraseIter iter; 10126 ** int iCol, iOff; 10127 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 10128 ** iCol>=0; 10129 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 10130 ** ){ 10131 ** // An instance of phrase iPhrase at offset iOff of column iCol 10132 ** } 10133 ** 10134 ** The Fts5PhraseIter structure is defined above. Applications should not 10135 ** modify this structure directly - it should only be used as shown above 10136 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 10137 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 10138 ** 10139 ** This API can be quite slow if used with an FTS5 table created with the 10140 ** "detail=none" or "detail=column" option. If the FTS5 table is created 10141 ** with either "detail=none" or "detail=column" and "content=" option 10142 ** (i.e. if it is a contentless table), then this API always iterates 10143 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 10144 ** 10145 ** xPhraseNext() 10146 ** See xPhraseFirst above. 10147 ** 10148 ** xPhraseFirstColumn() 10149 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 10150 ** and xPhraseNext() APIs described above. The difference is that instead 10151 ** of iterating through all instances of a phrase in the current row, these 10152 ** APIs are used to iterate through the set of columns in the current row 10153 ** that contain one or more instances of a specified phrase. For example: 10154 ** 10155 ** Fts5PhraseIter iter; 10156 ** int iCol; 10157 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 10158 ** iCol>=0; 10159 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 10160 ** ){ 10161 ** // Column iCol contains at least one instance of phrase iPhrase 10162 ** } 10163 ** 10164 ** This API can be quite slow if used with an FTS5 table created with the 10165 ** "detail=none" option. If the FTS5 table is created with either 10166 ** "detail=none" "content=" option (i.e. if it is a contentless table), 10167 ** then this API always iterates through an empty set (all calls to 10168 ** xPhraseFirstColumn() set iCol to -1). 10169 ** 10170 ** The information accessed using this API and its companion 10171 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 10172 ** (or xInst/xInstCount). The chief advantage of this API is that it is 10173 ** significantly more efficient than those alternatives when used with 10174 ** "detail=column" tables. 10175 ** 10176 ** xPhraseNextColumn() 10177 ** See xPhraseFirstColumn above. 10178 */ 10179 struct Fts5ExtensionApi { 10180 int iVersion; /* Currently always set to 3 */ 10181 10182 void *(*xUserData)(Fts5Context*); 10183 10184 int (*xColumnCount)(Fts5Context*); 10185 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 10186 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 10187 10188 int (*xTokenize)(Fts5Context*, 10189 const char *pText, int nText, /* Text to tokenize */ 10190 void *pCtx, /* Context passed to xToken() */ 10191 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 10192 ); 10193 10194 int (*xPhraseCount)(Fts5Context*); 10195 int (*xPhraseSize)(Fts5Context*, int iPhrase); 10196 10197 int (*xInstCount)(Fts5Context*, int *pnInst); 10198 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 10199 10200 sqlite3_int64 (*xRowid)(Fts5Context*); 10201 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 10202 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 10203 10204 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 10205 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 10206 ); 10207 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 10208 void *(*xGetAuxdata)(Fts5Context*, int bClear); 10209 10210 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 10211 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 10212 10213 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 10214 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 10215 }; 10216 10217 /* 10218 ** CUSTOM AUXILIARY FUNCTIONS 10219 *************************************************************************/ 10220 10221 /************************************************************************* 10222 ** CUSTOM TOKENIZERS 10223 ** 10224 ** Applications may also register custom tokenizer types. A tokenizer 10225 ** is registered by providing fts5 with a populated instance of the 10226 ** following structure. All structure methods must be defined, setting 10227 ** any member of the fts5_tokenizer struct to NULL leads to undefined 10228 ** behaviour. The structure methods are expected to function as follows: 10229 ** 10230 ** xCreate: 10231 ** This function is used to allocate and initialize a tokenizer instance. 10232 ** A tokenizer instance is required to actually tokenize text. 10233 ** 10234 ** The first argument passed to this function is a copy of the (void*) 10235 ** pointer provided by the application when the fts5_tokenizer object 10236 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 10237 ** The second and third arguments are an array of nul-terminated strings 10238 ** containing the tokenizer arguments, if any, specified following the 10239 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 10240 ** to create the FTS5 table. 10241 ** 10242 ** The final argument is an output variable. If successful, (*ppOut) 10243 ** should be set to point to the new tokenizer handle and SQLITE_OK 10244 ** returned. If an error occurs, some value other than SQLITE_OK should 10245 ** be returned. In this case, fts5 assumes that the final value of *ppOut 10246 ** is undefined. 10247 ** 10248 ** xDelete: 10249 ** This function is invoked to delete a tokenizer handle previously 10250 ** allocated using xCreate(). Fts5 guarantees that this function will 10251 ** be invoked exactly once for each successful call to xCreate(). 10252 ** 10253 ** xTokenize: 10254 ** This function is expected to tokenize the nText byte string indicated 10255 ** by argument pText. pText may or may not be nul-terminated. The first 10256 ** argument passed to this function is a pointer to an Fts5Tokenizer object 10257 ** returned by an earlier call to xCreate(). 10258 ** 10259 ** The second argument indicates the reason that FTS5 is requesting 10260 ** tokenization of the supplied text. This is always one of the following 10261 ** four values: 10262 ** 10263 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 10264 ** or removed from the FTS table. The tokenizer is being invoked to 10265 ** determine the set of tokens to add to (or delete from) the 10266 ** FTS index. 10267 ** 10268 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 10269 ** against the FTS index. The tokenizer is being called to tokenize 10270 ** a bareword or quoted string specified as part of the query. 10271 ** 10272 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 10273 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 10274 ** followed by a "*" character, indicating that the last token 10275 ** returned by the tokenizer will be treated as a token prefix. 10276 ** 10277 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 10278 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 10279 ** function. Or an fts5_api.xColumnSize() request made by the same 10280 ** on a columnsize=0 database. 10281 ** </ul> 10282 ** 10283 ** For each token in the input string, the supplied callback xToken() must 10284 ** be invoked. The first argument to it should be a copy of the pointer 10285 ** passed as the second argument to xTokenize(). The third and fourth 10286 ** arguments are a pointer to a buffer containing the token text, and the 10287 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 10288 ** of the first byte of and first byte immediately following the text from 10289 ** which the token is derived within the input. 10290 ** 10291 ** The second argument passed to the xToken() callback ("tflags") should 10292 ** normally be set to 0. The exception is if the tokenizer supports 10293 ** synonyms. In this case see the discussion below for details. 10294 ** 10295 ** FTS5 assumes the xToken() callback is invoked for each token in the 10296 ** order that they occur within the input text. 10297 ** 10298 ** If an xToken() callback returns any value other than SQLITE_OK, then 10299 ** the tokenization should be abandoned and the xTokenize() method should 10300 ** immediately return a copy of the xToken() return value. Or, if the 10301 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 10302 ** if an error occurs with the xTokenize() implementation itself, it 10303 ** may abandon the tokenization and return any error code other than 10304 ** SQLITE_OK or SQLITE_DONE. 10305 ** 10306 ** SYNONYM SUPPORT 10307 ** 10308 ** Custom tokenizers may also support synonyms. Consider a case in which a 10309 ** user wishes to query for a phrase such as "first place". Using the 10310 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 10311 ** of "first place" within the document set, but not alternative forms 10312 ** such as "1st place". In some applications, it would be better to match 10313 ** all instances of "first place" or "1st place" regardless of which form 10314 ** the user specified in the MATCH query text. 10315 ** 10316 ** There are several ways to approach this in FTS5: 10317 ** 10318 ** <ol><li> By mapping all synonyms to a single token. In this case, the 10319 ** In the above example, this means that the tokenizer returns the 10320 ** same token for inputs "first" and "1st". Say that token is in 10321 ** fact "first", so that when the user inserts the document "I won 10322 ** 1st place" entries are added to the index for tokens "i", "won", 10323 ** "first" and "place". If the user then queries for '1st + place', 10324 ** the tokenizer substitutes "first" for "1st" and the query works 10325 ** as expected. 10326 ** 10327 ** <li> By adding multiple synonyms for a single term to the FTS index. 10328 ** In this case, when tokenizing query text, the tokenizer may 10329 ** provide multiple synonyms for a single term within the document. 10330 ** FTS5 then queries the index for each synonym individually. For 10331 ** example, faced with the query: 10332 ** 10333 ** <codeblock> 10334 ** ... MATCH 'first place'</codeblock> 10335 ** 10336 ** the tokenizer offers both "1st" and "first" as synonyms for the 10337 ** first token in the MATCH query and FTS5 effectively runs a query 10338 ** similar to: 10339 ** 10340 ** <codeblock> 10341 ** ... MATCH '(first OR 1st) place'</codeblock> 10342 ** 10343 ** except that, for the purposes of auxiliary functions, the query 10344 ** still appears to contain just two phrases - "(first OR 1st)" 10345 ** being treated as a single phrase. 10346 ** 10347 ** <li> By adding multiple synonyms for a single term to the FTS index. 10348 ** Using this method, when tokenizing document text, the tokenizer 10349 ** provides multiple synonyms for each token. So that when a 10350 ** document such as "I won first place" is tokenized, entries are 10351 ** added to the FTS index for "i", "won", "first", "1st" and 10352 ** "place". 10353 ** 10354 ** This way, even if the tokenizer does not provide synonyms 10355 ** when tokenizing query text (it should not - to do would be 10356 ** inefficient), it doesn't matter if the user queries for 10357 ** 'first + place' or '1st + place', as there are entires in the 10358 ** FTS index corresponding to both forms of the first token. 10359 ** </ol> 10360 ** 10361 ** Whether it is parsing document or query text, any call to xToken that 10362 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 10363 ** is considered to supply a synonym for the previous token. For example, 10364 ** when parsing the document "I won first place", a tokenizer that supports 10365 ** synonyms would call xToken() 5 times, as follows: 10366 ** 10367 ** <codeblock> 10368 ** xToken(pCtx, 0, "i", 1, 0, 1); 10369 ** xToken(pCtx, 0, "won", 3, 2, 5); 10370 ** xToken(pCtx, 0, "first", 5, 6, 11); 10371 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 10372 ** xToken(pCtx, 0, "place", 5, 12, 17); 10373 **</codeblock> 10374 ** 10375 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 10376 ** xToken() is called. Multiple synonyms may be specified for a single token 10377 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 10378 ** There is no limit to the number of synonyms that may be provided for a 10379 ** single token. 10380 ** 10381 ** In many cases, method (1) above is the best approach. It does not add 10382 ** extra data to the FTS index or require FTS5 to query for multiple terms, 10383 ** so it is efficient in terms of disk space and query speed. However, it 10384 ** does not support prefix queries very well. If, as suggested above, the 10385 ** token "first" is subsituted for "1st" by the tokenizer, then the query: 10386 ** 10387 ** <codeblock> 10388 ** ... MATCH '1s*'</codeblock> 10389 ** 10390 ** will not match documents that contain the token "1st" (as the tokenizer 10391 ** will probably not map "1s" to any prefix of "first"). 10392 ** 10393 ** For full prefix support, method (3) may be preferred. In this case, 10394 ** because the index contains entries for both "first" and "1st", prefix 10395 ** queries such as 'fi*' or '1s*' will match correctly. However, because 10396 ** extra entries are added to the FTS index, this method uses more space 10397 ** within the database. 10398 ** 10399 ** Method (2) offers a midpoint between (1) and (3). Using this method, 10400 ** a query such as '1s*' will match documents that contain the literal 10401 ** token "1st", but not "first" (assuming the tokenizer is not able to 10402 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 10403 ** will match against "1st" and "first". This method does not require 10404 ** extra disk space, as no extra entries are added to the FTS index. 10405 ** On the other hand, it may require more CPU cycles to run MATCH queries, 10406 ** as separate queries of the FTS index are required for each synonym. 10407 ** 10408 ** When using methods (2) or (3), it is important that the tokenizer only 10409 ** provide synonyms when tokenizing document text (method (2)) or query 10410 ** text (method (3)), not both. Doing so will not cause any errors, but is 10411 ** inefficient. 10412 */ 10413 typedef struct Fts5Tokenizer Fts5Tokenizer; 10414 typedef struct fts5_tokenizer fts5_tokenizer; 10415 struct fts5_tokenizer { 10416 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 10417 void (*xDelete)(Fts5Tokenizer*); 10418 int (*xTokenize)(Fts5Tokenizer*, 10419 void *pCtx, 10420 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 10421 const char *pText, int nText, 10422 int (*xToken)( 10423 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 10424 int tflags, /* Mask of FTS5_TOKEN_* flags */ 10425 const char *pToken, /* Pointer to buffer containing token */ 10426 int nToken, /* Size of token in bytes */ 10427 int iStart, /* Byte offset of token within input text */ 10428 int iEnd /* Byte offset of end of token within input text */ 10429 ) 10430 ); 10431 }; 10432 10433 /* Flags that may be passed as the third argument to xTokenize() */ 10434 #define FTS5_TOKENIZE_QUERY 0x0001 10435 #define FTS5_TOKENIZE_PREFIX 0x0002 10436 #define FTS5_TOKENIZE_DOCUMENT 0x0004 10437 #define FTS5_TOKENIZE_AUX 0x0008 10438 10439 /* Flags that may be passed by the tokenizer implementation back to FTS5 10440 ** as the third argument to the supplied xToken callback. */ 10441 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 10442 10443 /* 10444 ** END OF CUSTOM TOKENIZERS 10445 *************************************************************************/ 10446 10447 /************************************************************************* 10448 ** FTS5 EXTENSION REGISTRATION API 10449 */ 10450 typedef struct fts5_api fts5_api; 10451 struct fts5_api { 10452 int iVersion; /* Currently always set to 2 */ 10453 10454 /* Create a new tokenizer */ 10455 int (*xCreateTokenizer)( 10456 fts5_api *pApi, 10457 const char *zName, 10458 void *pContext, 10459 fts5_tokenizer *pTokenizer, 10460 void (*xDestroy)(void*) 10461 ); 10462 10463 /* Find an existing tokenizer */ 10464 int (*xFindTokenizer)( 10465 fts5_api *pApi, 10466 const char *zName, 10467 void **ppContext, 10468 fts5_tokenizer *pTokenizer 10469 ); 10470 10471 /* Create a new auxiliary function */ 10472 int (*xCreateFunction)( 10473 fts5_api *pApi, 10474 const char *zName, 10475 void *pContext, 10476 fts5_extension_function xFunction, 10477 void (*xDestroy)(void*) 10478 ); 10479 }; 10480 10481 /* 10482 ** END OF REGISTRATION API 10483 *************************************************************************/ 10484 10485 #ifdef __cplusplus 10486 } /* end of the 'extern "C"' block */ 10487 #endif 10488 10489 #endif /* _FTS5_H */ 10490 10491 /******** End of fts5.h *********/ 10492