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 suppose to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef _SQLITE3_H_ 34 #define _SQLITE3_H_ 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_STDCALL 58 # define SQLITE_STDCALL 59 #endif 60 61 /* 62 ** These no-op macros are used in front of interfaces to mark those 63 ** interfaces as either deprecated or experimental. New applications 64 ** should not use deprecated interfaces - they are supported for backwards 65 ** compatibility only. Application writers should be aware that 66 ** experimental interfaces are subject to change in point releases. 67 ** 68 ** These macros used to resolve to various kinds of compiler magic that 69 ** would generate warning messages when they were used. But that 70 ** compiler magic ended up generating such a flurry of bug reports 71 ** that we have taken it all out and gone back to using simple 72 ** noop macros. 73 */ 74 #define SQLITE_DEPRECATED 75 #define SQLITE_EXPERIMENTAL 76 77 /* 78 ** Ensure these symbols were not defined by some previous header file. 79 */ 80 #ifdef SQLITE_VERSION 81 # undef SQLITE_VERSION 82 #endif 83 #ifdef SQLITE_VERSION_NUMBER 84 # undef SQLITE_VERSION_NUMBER 85 #endif 86 87 /* 88 ** CAPI3REF: Compile-Time Library Version Numbers 89 ** 90 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 91 ** evaluates to a string literal that is the SQLite version in the 92 ** format "X.Y.Z" where X is the major version number (always 3 for 93 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 94 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 95 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 96 ** numbers used in [SQLITE_VERSION].)^ 97 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 98 ** be larger than the release from which it is derived. Either Y will 99 ** be held constant and Z will be incremented or else Y will be incremented 100 ** and Z will be reset to zero. 101 ** 102 ** Since version 3.6.18, SQLite source code has been stored in the 103 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 104 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 105 ** a string which identifies a particular check-in of SQLite 106 ** within its configuration management system. ^The SQLITE_SOURCE_ID 107 ** string contains the date and time of the check-in (UTC) and an SHA1 108 ** hash of the entire source tree. 109 ** 110 ** See also: [sqlite3_libversion()], 111 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 112 ** [sqlite_version()] and [sqlite_source_id()]. 113 */ 114 #define SQLITE_VERSION "3.8.10.2" 115 #define SQLITE_VERSION_NUMBER 3008010 116 #define SQLITE_SOURCE_ID "2015-05-20 18:17:19 2ef4f3a5b1d1d0c4338f8243d40a2452cc1f7fe4" 117 118 /* 119 ** CAPI3REF: Run-Time Library Version Numbers 120 ** KEYWORDS: sqlite3_version, sqlite3_sourceid 121 ** 122 ** These interfaces provide the same information as the [SQLITE_VERSION], 123 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 124 ** but are associated with the library instead of the header file. ^(Cautious 125 ** programmers might include assert() statements in their application to 126 ** verify that values returned by these interfaces match the macros in 127 ** the header, and thus insure that the application is 128 ** compiled with matching library and header files. 129 ** 130 ** <blockquote><pre> 131 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 132 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 133 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 134 ** </pre></blockquote>)^ 135 ** 136 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 137 ** macro. ^The sqlite3_libversion() function returns a pointer to the 138 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 139 ** function is provided for use in DLLs since DLL users usually do not have 140 ** direct access to string constants within the DLL. ^The 141 ** sqlite3_libversion_number() function returns an integer equal to 142 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 143 ** a pointer to a string constant whose value is the same as the 144 ** [SQLITE_SOURCE_ID] C preprocessor macro. 145 ** 146 ** See also: [sqlite_version()] and [sqlite_source_id()]. 147 */ 148 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 149 SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void); 150 SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void); 151 SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void); 152 153 /* 154 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 155 ** 156 ** ^The sqlite3_compileoption_used() function returns 0 or 1 157 ** indicating whether the specified option was defined at 158 ** compile time. ^The SQLITE_ prefix may be omitted from the 159 ** option name passed to sqlite3_compileoption_used(). 160 ** 161 ** ^The sqlite3_compileoption_get() function allows iterating 162 ** over the list of options that were defined at compile time by 163 ** returning the N-th compile time option string. ^If N is out of range, 164 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 165 ** prefix is omitted from any strings returned by 166 ** sqlite3_compileoption_get(). 167 ** 168 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 169 ** and sqlite3_compileoption_get() may be omitted by specifying the 170 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 171 ** 172 ** See also: SQL functions [sqlite_compileoption_used()] and 173 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 174 */ 175 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 176 SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName); 177 SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N); 178 #endif 179 180 /* 181 ** CAPI3REF: Test To See If The Library Is Threadsafe 182 ** 183 ** ^The sqlite3_threadsafe() function returns zero if and only if 184 ** SQLite was compiled with mutexing code omitted due to the 185 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 186 ** 187 ** SQLite can be compiled with or without mutexes. When 188 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 189 ** are enabled and SQLite is threadsafe. When the 190 ** [SQLITE_THREADSAFE] macro is 0, 191 ** the mutexes are omitted. Without the mutexes, it is not safe 192 ** to use SQLite concurrently from more than one thread. 193 ** 194 ** Enabling mutexes incurs a measurable performance penalty. 195 ** So if speed is of utmost importance, it makes sense to disable 196 ** the mutexes. But for maximum safety, mutexes should be enabled. 197 ** ^The default behavior is for mutexes to be enabled. 198 ** 199 ** This interface can be used by an application to make sure that the 200 ** version of SQLite that it is linking against was compiled with 201 ** the desired setting of the [SQLITE_THREADSAFE] macro. 202 ** 203 ** This interface only reports on the compile-time mutex setting 204 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 205 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 206 ** can be fully or partially disabled using a call to [sqlite3_config()] 207 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 208 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 209 ** sqlite3_threadsafe() function shows only the compile-time setting of 210 ** thread safety, not any run-time changes to that setting made by 211 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 212 ** is unchanged by calls to sqlite3_config().)^ 213 ** 214 ** See the [threading mode] documentation for additional information. 215 */ 216 SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void); 217 218 /* 219 ** CAPI3REF: Database Connection Handle 220 ** KEYWORDS: {database connection} {database connections} 221 ** 222 ** Each open SQLite database is represented by a pointer to an instance of 223 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 224 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 225 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 226 ** and [sqlite3_close_v2()] are its destructors. There are many other 227 ** interfaces (such as 228 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 229 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 230 ** sqlite3 object. 231 */ 232 typedef struct sqlite3 sqlite3; 233 234 /* 235 ** CAPI3REF: 64-Bit Integer Types 236 ** KEYWORDS: sqlite_int64 sqlite_uint64 237 ** 238 ** Because there is no cross-platform way to specify 64-bit integer types 239 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 240 ** 241 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 242 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 243 ** compatibility only. 244 ** 245 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 246 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 247 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 248 ** between 0 and +18446744073709551615 inclusive. 249 */ 250 #ifdef SQLITE_INT64_TYPE 251 typedef SQLITE_INT64_TYPE sqlite_int64; 252 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 253 #elif defined(_MSC_VER) || defined(__BORLANDC__) 254 typedef __int64 sqlite_int64; 255 typedef unsigned __int64 sqlite_uint64; 256 #else 257 typedef long long int sqlite_int64; 258 typedef unsigned long long int sqlite_uint64; 259 #endif 260 typedef sqlite_int64 sqlite3_int64; 261 typedef sqlite_uint64 sqlite3_uint64; 262 263 /* 264 ** If compiling for a processor that lacks floating point support, 265 ** substitute integer for floating-point. 266 */ 267 #ifdef SQLITE_OMIT_FLOATING_POINT 268 # define double sqlite3_int64 269 #endif 270 271 /* 272 ** CAPI3REF: Closing A Database Connection 273 ** DESTRUCTOR: sqlite3 274 ** 275 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 276 ** for the [sqlite3] object. 277 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 278 ** the [sqlite3] object is successfully destroyed and all associated 279 ** resources are deallocated. 280 ** 281 ** ^If the database connection is associated with unfinalized prepared 282 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 283 ** will leave the database connection open and return [SQLITE_BUSY]. 284 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 285 ** and/or unfinished sqlite3_backups, then the database connection becomes 286 ** an unusable "zombie" which will automatically be deallocated when the 287 ** last prepared statement is finalized or the last sqlite3_backup is 288 ** finished. The sqlite3_close_v2() interface is intended for use with 289 ** host languages that are garbage collected, and where the order in which 290 ** destructors are called is arbitrary. 291 ** 292 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 293 ** [sqlite3_blob_close | close] all [BLOB handles], and 294 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 295 ** with the [sqlite3] object prior to attempting to close the object. ^If 296 ** sqlite3_close_v2() is called on a [database connection] that still has 297 ** outstanding [prepared statements], [BLOB handles], and/or 298 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 299 ** of resources is deferred until all [prepared statements], [BLOB handles], 300 ** and [sqlite3_backup] objects are also destroyed. 301 ** 302 ** ^If an [sqlite3] object is destroyed while a transaction is open, 303 ** the transaction is automatically rolled back. 304 ** 305 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 306 ** must be either a NULL 307 ** pointer or an [sqlite3] object pointer obtained 308 ** from [sqlite3_open()], [sqlite3_open16()], or 309 ** [sqlite3_open_v2()], and not previously closed. 310 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 311 ** argument is a harmless no-op. 312 */ 313 SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*); 314 SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*); 315 316 /* 317 ** The type for a callback function. 318 ** This is legacy and deprecated. It is included for historical 319 ** compatibility and is not documented. 320 */ 321 typedef int (*sqlite3_callback)(void*,int,char**, char**); 322 323 /* 324 ** CAPI3REF: One-Step Query Execution Interface 325 ** METHOD: sqlite3 326 ** 327 ** The sqlite3_exec() interface is a convenience wrapper around 328 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 329 ** that allows an application to run multiple statements of SQL 330 ** without having to use a lot of C code. 331 ** 332 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 333 ** semicolon-separate SQL statements passed into its 2nd argument, 334 ** in the context of the [database connection] passed in as its 1st 335 ** argument. ^If the callback function of the 3rd argument to 336 ** sqlite3_exec() is not NULL, then it is invoked for each result row 337 ** coming out of the evaluated SQL statements. ^The 4th argument to 338 ** sqlite3_exec() is relayed through to the 1st argument of each 339 ** callback invocation. ^If the callback pointer to sqlite3_exec() 340 ** is NULL, then no callback is ever invoked and result rows are 341 ** ignored. 342 ** 343 ** ^If an error occurs while evaluating the SQL statements passed into 344 ** sqlite3_exec(), then execution of the current statement stops and 345 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 346 ** is not NULL then any error message is written into memory obtained 347 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 348 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 349 ** on error message strings returned through the 5th parameter of 350 ** of sqlite3_exec() after the error message string is no longer needed. 351 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 352 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 353 ** NULL before returning. 354 ** 355 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 356 ** routine returns SQLITE_ABORT without invoking the callback again and 357 ** without running any subsequent SQL statements. 358 ** 359 ** ^The 2nd argument to the sqlite3_exec() callback function is the 360 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 361 ** callback is an array of pointers to strings obtained as if from 362 ** [sqlite3_column_text()], one for each column. ^If an element of a 363 ** result row is NULL then the corresponding string pointer for the 364 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 365 ** sqlite3_exec() callback is an array of pointers to strings where each 366 ** entry represents the name of corresponding result column as obtained 367 ** from [sqlite3_column_name()]. 368 ** 369 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 370 ** to an empty string, or a pointer that contains only whitespace and/or 371 ** SQL comments, then no SQL statements are evaluated and the database 372 ** is not changed. 373 ** 374 ** Restrictions: 375 ** 376 ** <ul> 377 ** <li> The application must insure that the 1st parameter to sqlite3_exec() 378 ** is a valid and open [database connection]. 379 ** <li> The application must not close the [database connection] specified by 380 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 381 ** <li> The application must not modify the SQL statement text passed into 382 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 383 ** </ul> 384 */ 385 SQLITE_API int SQLITE_STDCALL sqlite3_exec( 386 sqlite3*, /* An open database */ 387 const char *sql, /* SQL to be evaluated */ 388 int (*callback)(void*,int,char**,char**), /* Callback function */ 389 void *, /* 1st argument to callback */ 390 char **errmsg /* Error msg written here */ 391 ); 392 393 /* 394 ** CAPI3REF: Result Codes 395 ** KEYWORDS: {result code definitions} 396 ** 397 ** Many SQLite functions return an integer result code from the set shown 398 ** here in order to indicate success or failure. 399 ** 400 ** New error codes may be added in future versions of SQLite. 401 ** 402 ** See also: [extended result code definitions] 403 */ 404 #define SQLITE_OK 0 /* Successful result */ 405 /* beginning-of-error-codes */ 406 #define SQLITE_ERROR 1 /* SQL error or missing database */ 407 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 408 #define SQLITE_PERM 3 /* Access permission denied */ 409 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 410 #define SQLITE_BUSY 5 /* The database file is locked */ 411 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 412 #define SQLITE_NOMEM 7 /* A malloc() failed */ 413 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 414 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 415 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 416 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 417 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 418 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 419 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 420 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 421 #define SQLITE_EMPTY 16 /* Database is empty */ 422 #define SQLITE_SCHEMA 17 /* The database schema changed */ 423 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 424 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 425 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 426 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 427 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 428 #define SQLITE_AUTH 23 /* Authorization denied */ 429 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 430 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 431 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 432 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 433 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 434 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 435 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 436 /* end-of-error-codes */ 437 438 /* 439 ** CAPI3REF: Extended Result Codes 440 ** KEYWORDS: {extended result code definitions} 441 ** 442 ** In its default configuration, SQLite API routines return one of 30 integer 443 ** [result codes]. However, experience has shown that many of 444 ** these result codes are too coarse-grained. They do not provide as 445 ** much information about problems as programmers might like. In an effort to 446 ** address this, newer versions of SQLite (version 3.3.8 and later) include 447 ** support for additional result codes that provide more detailed information 448 ** about errors. These [extended result codes] are enabled or disabled 449 ** on a per database connection basis using the 450 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 451 ** the most recent error can be obtained using 452 ** [sqlite3_extended_errcode()]. 453 */ 454 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 455 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 456 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 457 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 458 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 459 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 460 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 461 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 462 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 463 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 464 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 465 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 466 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 467 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 468 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 469 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 470 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 471 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 472 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 473 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 474 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 475 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 476 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 477 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 478 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 479 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 480 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 481 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 482 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 483 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 484 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 485 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 486 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 487 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 488 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 489 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 490 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 491 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 492 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 493 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 494 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 495 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 496 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 497 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 498 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 499 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 500 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 501 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 502 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 503 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 504 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 505 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 506 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 507 508 /* 509 ** CAPI3REF: Flags For File Open Operations 510 ** 511 ** These bit values are intended for use in the 512 ** 3rd parameter to the [sqlite3_open_v2()] interface and 513 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 514 */ 515 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 516 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 517 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 518 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 519 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 520 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 521 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 522 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 523 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 524 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 525 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 526 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 527 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 528 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 529 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 530 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 531 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 532 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 533 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 534 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 535 536 /* Reserved: 0x00F00000 */ 537 538 /* 539 ** CAPI3REF: Device Characteristics 540 ** 541 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 542 ** object returns an integer which is a vector of these 543 ** bit values expressing I/O characteristics of the mass storage 544 ** device that holds the file that the [sqlite3_io_methods] 545 ** refers to. 546 ** 547 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 548 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 549 ** mean that writes of blocks that are nnn bytes in size and 550 ** are aligned to an address which is an integer multiple of 551 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 552 ** that when data is appended to a file, the data is appended 553 ** first then the size of the file is extended, never the other 554 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 555 ** information is written to disk in the same order as calls 556 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 557 ** after reboot following a crash or power loss, the only bytes in a 558 ** file that were written at the application level might have changed 559 ** and that adjacent bytes, even bytes within the same sector are 560 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 561 ** flag indicate that a file cannot be deleted when open. The 562 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 563 ** read-only media and cannot be changed even by processes with 564 ** elevated privileges. 565 */ 566 #define SQLITE_IOCAP_ATOMIC 0x00000001 567 #define SQLITE_IOCAP_ATOMIC512 0x00000002 568 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 569 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 570 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 571 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 572 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 573 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 574 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 575 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 576 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 577 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 578 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 579 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 580 581 /* 582 ** CAPI3REF: File Locking Levels 583 ** 584 ** SQLite uses one of these integer values as the second 585 ** argument to calls it makes to the xLock() and xUnlock() methods 586 ** of an [sqlite3_io_methods] object. 587 */ 588 #define SQLITE_LOCK_NONE 0 589 #define SQLITE_LOCK_SHARED 1 590 #define SQLITE_LOCK_RESERVED 2 591 #define SQLITE_LOCK_PENDING 3 592 #define SQLITE_LOCK_EXCLUSIVE 4 593 594 /* 595 ** CAPI3REF: Synchronization Type Flags 596 ** 597 ** When SQLite invokes the xSync() method of an 598 ** [sqlite3_io_methods] object it uses a combination of 599 ** these integer values as the second argument. 600 ** 601 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 602 ** sync operation only needs to flush data to mass storage. Inode 603 ** information need not be flushed. If the lower four bits of the flag 604 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 605 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 606 ** to use Mac OS X style fullsync instead of fsync(). 607 ** 608 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 609 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 610 ** settings. The [synchronous pragma] determines when calls to the 611 ** xSync VFS method occur and applies uniformly across all platforms. 612 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 613 ** energetic or rigorous or forceful the sync operations are and 614 ** only make a difference on Mac OSX for the default SQLite code. 615 ** (Third-party VFS implementations might also make the distinction 616 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 617 ** operating systems natively supported by SQLite, only Mac OSX 618 ** cares about the difference.) 619 */ 620 #define SQLITE_SYNC_NORMAL 0x00002 621 #define SQLITE_SYNC_FULL 0x00003 622 #define SQLITE_SYNC_DATAONLY 0x00010 623 624 /* 625 ** CAPI3REF: OS Interface Open File Handle 626 ** 627 ** An [sqlite3_file] object represents an open file in the 628 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 629 ** implementations will 630 ** want to subclass this object by appending additional fields 631 ** for their own use. The pMethods entry is a pointer to an 632 ** [sqlite3_io_methods] object that defines methods for performing 633 ** I/O operations on the open file. 634 */ 635 typedef struct sqlite3_file sqlite3_file; 636 struct sqlite3_file { 637 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 638 }; 639 640 /* 641 ** CAPI3REF: OS Interface File Virtual Methods Object 642 ** 643 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 644 ** [sqlite3_file] object (or, more commonly, a subclass of the 645 ** [sqlite3_file] object) with a pointer to an instance of this object. 646 ** This object defines the methods used to perform various operations 647 ** against the open file represented by the [sqlite3_file] object. 648 ** 649 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 650 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 651 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 652 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 653 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 654 ** to NULL. 655 ** 656 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 657 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 658 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 659 ** flag may be ORed in to indicate that only the data of the file 660 ** and not its inode needs to be synced. 661 ** 662 ** The integer values to xLock() and xUnlock() are one of 663 ** <ul> 664 ** <li> [SQLITE_LOCK_NONE], 665 ** <li> [SQLITE_LOCK_SHARED], 666 ** <li> [SQLITE_LOCK_RESERVED], 667 ** <li> [SQLITE_LOCK_PENDING], or 668 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 669 ** </ul> 670 ** xLock() increases the lock. xUnlock() decreases the lock. 671 ** The xCheckReservedLock() method checks whether any database connection, 672 ** either in this process or in some other process, is holding a RESERVED, 673 ** PENDING, or EXCLUSIVE lock on the file. It returns true 674 ** if such a lock exists and false otherwise. 675 ** 676 ** The xFileControl() method is a generic interface that allows custom 677 ** VFS implementations to directly control an open file using the 678 ** [sqlite3_file_control()] interface. The second "op" argument is an 679 ** integer opcode. The third argument is a generic pointer intended to 680 ** point to a structure that may contain arguments or space in which to 681 ** write return values. Potential uses for xFileControl() might be 682 ** functions to enable blocking locks with timeouts, to change the 683 ** locking strategy (for example to use dot-file locks), to inquire 684 ** about the status of a lock, or to break stale locks. The SQLite 685 ** core reserves all opcodes less than 100 for its own use. 686 ** A [file control opcodes | list of opcodes] less than 100 is available. 687 ** Applications that define a custom xFileControl method should use opcodes 688 ** greater than 100 to avoid conflicts. VFS implementations should 689 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 690 ** recognize. 691 ** 692 ** The xSectorSize() method returns the sector size of the 693 ** device that underlies the file. The sector size is the 694 ** minimum write that can be performed without disturbing 695 ** other bytes in the file. The xDeviceCharacteristics() 696 ** method returns a bit vector describing behaviors of the 697 ** underlying device: 698 ** 699 ** <ul> 700 ** <li> [SQLITE_IOCAP_ATOMIC] 701 ** <li> [SQLITE_IOCAP_ATOMIC512] 702 ** <li> [SQLITE_IOCAP_ATOMIC1K] 703 ** <li> [SQLITE_IOCAP_ATOMIC2K] 704 ** <li> [SQLITE_IOCAP_ATOMIC4K] 705 ** <li> [SQLITE_IOCAP_ATOMIC8K] 706 ** <li> [SQLITE_IOCAP_ATOMIC16K] 707 ** <li> [SQLITE_IOCAP_ATOMIC32K] 708 ** <li> [SQLITE_IOCAP_ATOMIC64K] 709 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 710 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 711 ** </ul> 712 ** 713 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 714 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 715 ** mean that writes of blocks that are nnn bytes in size and 716 ** are aligned to an address which is an integer multiple of 717 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 718 ** that when data is appended to a file, the data is appended 719 ** first then the size of the file is extended, never the other 720 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 721 ** information is written to disk in the same order as calls 722 ** to xWrite(). 723 ** 724 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 725 ** in the unread portions of the buffer with zeros. A VFS that 726 ** fails to zero-fill short reads might seem to work. However, 727 ** failure to zero-fill short reads will eventually lead to 728 ** database corruption. 729 */ 730 typedef struct sqlite3_io_methods sqlite3_io_methods; 731 struct sqlite3_io_methods { 732 int iVersion; 733 int (*xClose)(sqlite3_file*); 734 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 735 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 736 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 737 int (*xSync)(sqlite3_file*, int flags); 738 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 739 int (*xLock)(sqlite3_file*, int); 740 int (*xUnlock)(sqlite3_file*, int); 741 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 742 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 743 int (*xSectorSize)(sqlite3_file*); 744 int (*xDeviceCharacteristics)(sqlite3_file*); 745 /* Methods above are valid for version 1 */ 746 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 747 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 748 void (*xShmBarrier)(sqlite3_file*); 749 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 750 /* Methods above are valid for version 2 */ 751 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 752 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 753 /* Methods above are valid for version 3 */ 754 /* Additional methods may be added in future releases */ 755 }; 756 757 /* 758 ** CAPI3REF: Standard File Control Opcodes 759 ** KEYWORDS: {file control opcodes} {file control opcode} 760 ** 761 ** These integer constants are opcodes for the xFileControl method 762 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 763 ** interface. 764 ** 765 ** <ul> 766 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 767 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 768 ** opcode causes the xFileControl method to write the current state of 769 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 770 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 771 ** into an integer that the pArg argument points to. This capability 772 ** is used during testing and is only available when the SQLITE_TEST 773 ** compile-time option is used. 774 ** 775 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 776 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 777 ** layer a hint of how large the database file will grow to be during the 778 ** current transaction. This hint is not guaranteed to be accurate but it 779 ** is often close. The underlying VFS might choose to preallocate database 780 ** file space based on this hint in order to help writes to the database 781 ** file run faster. 782 ** 783 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 784 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 785 ** extends and truncates the database file in chunks of a size specified 786 ** by the user. The fourth argument to [sqlite3_file_control()] should 787 ** point to an integer (type int) containing the new chunk-size to use 788 ** for the nominated database. Allocating database file space in large 789 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 790 ** improve performance on some systems. 791 ** 792 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 793 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 794 ** to the [sqlite3_file] object associated with a particular database 795 ** connection. See the [sqlite3_file_control()] documentation for 796 ** additional information. 797 ** 798 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 799 ** No longer in use. 800 ** 801 ** <li>[[SQLITE_FCNTL_SYNC]] 802 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 803 ** sent to the VFS immediately before the xSync method is invoked on a 804 ** database file descriptor. Or, if the xSync method is not invoked 805 ** because the user has configured SQLite with 806 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 807 ** of the xSync method. In most cases, the pointer argument passed with 808 ** this file-control is NULL. However, if the database file is being synced 809 ** as part of a multi-database commit, the argument points to a nul-terminated 810 ** string containing the transactions master-journal file name. VFSes that 811 ** do not need this signal should silently ignore this opcode. Applications 812 ** should not call [sqlite3_file_control()] with this opcode as doing so may 813 ** disrupt the operation of the specialized VFSes that do require it. 814 ** 815 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 816 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 817 ** and sent to the VFS after a transaction has been committed immediately 818 ** but before the database is unlocked. VFSes that do not need this signal 819 ** should silently ignore this opcode. Applications should not call 820 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 821 ** operation of the specialized VFSes that do require it. 822 ** 823 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 824 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 825 ** retry counts and intervals for certain disk I/O operations for the 826 ** windows [VFS] in order to provide robustness in the presence of 827 ** anti-virus programs. By default, the windows VFS will retry file read, 828 ** file write, and file delete operations up to 10 times, with a delay 829 ** of 25 milliseconds before the first retry and with the delay increasing 830 ** by an additional 25 milliseconds with each subsequent retry. This 831 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 832 ** to be adjusted. The values are changed for all database connections 833 ** within the same process. The argument is a pointer to an array of two 834 ** integers where the first integer i the new retry count and the second 835 ** integer is the delay. If either integer is negative, then the setting 836 ** is not changed but instead the prior value of that setting is written 837 ** into the array entry, allowing the current retry settings to be 838 ** interrogated. The zDbName parameter is ignored. 839 ** 840 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 841 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 842 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 843 ** write ahead log and shared memory files used for transaction control 844 ** are automatically deleted when the latest connection to the database 845 ** closes. Setting persistent WAL mode causes those files to persist after 846 ** close. Persisting the files is useful when other processes that do not 847 ** have write permission on the directory containing the database file want 848 ** to read the database file, as the WAL and shared memory files must exist 849 ** in order for the database to be readable. The fourth parameter to 850 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 851 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 852 ** WAL mode. If the integer is -1, then it is overwritten with the current 853 ** WAL persistence setting. 854 ** 855 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 856 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 857 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 858 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 859 ** xDeviceCharacteristics methods. The fourth parameter to 860 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 861 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 862 ** mode. If the integer is -1, then it is overwritten with the current 863 ** zero-damage mode setting. 864 ** 865 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 866 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 867 ** a write transaction to indicate that, unless it is rolled back for some 868 ** reason, the entire database file will be overwritten by the current 869 ** transaction. This is used by VACUUM operations. 870 ** 871 ** <li>[[SQLITE_FCNTL_VFSNAME]] 872 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 873 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 874 ** final bottom-level VFS are written into memory obtained from 875 ** [sqlite3_malloc()] and the result is stored in the char* variable 876 ** that the fourth parameter of [sqlite3_file_control()] points to. 877 ** The caller is responsible for freeing the memory when done. As with 878 ** all file-control actions, there is no guarantee that this will actually 879 ** do anything. Callers should initialize the char* variable to a NULL 880 ** pointer in case this file-control is not implemented. This file-control 881 ** is intended for diagnostic use only. 882 ** 883 ** <li>[[SQLITE_FCNTL_PRAGMA]] 884 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 885 ** file control is sent to the open [sqlite3_file] object corresponding 886 ** to the database file to which the pragma statement refers. ^The argument 887 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 888 ** pointers to strings (char**) in which the second element of the array 889 ** is the name of the pragma and the third element is the argument to the 890 ** pragma or NULL if the pragma has no argument. ^The handler for an 891 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 892 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 893 ** or the equivalent and that string will become the result of the pragma or 894 ** the error message if the pragma fails. ^If the 895 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 896 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 897 ** file control returns [SQLITE_OK], then the parser assumes that the 898 ** VFS has handled the PRAGMA itself and the parser generates a no-op 899 ** prepared statement if result string is NULL, or that returns a copy 900 ** of the result string if the string is non-NULL. 901 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 902 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 903 ** that the VFS encountered an error while handling the [PRAGMA] and the 904 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 905 ** file control occurs at the beginning of pragma statement analysis and so 906 ** it is able to override built-in [PRAGMA] statements. 907 ** 908 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 909 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 910 ** file-control may be invoked by SQLite on the database file handle 911 ** shortly after it is opened in order to provide a custom VFS with access 912 ** to the connections busy-handler callback. The argument is of type (void **) 913 ** - an array of two (void *) values. The first (void *) actually points 914 ** to a function of type (int (*)(void *)). In order to invoke the connections 915 ** busy-handler, this function should be invoked with the second (void *) in 916 ** the array as the only argument. If it returns non-zero, then the operation 917 ** should be retried. If it returns zero, the custom VFS should abandon the 918 ** current operation. 919 ** 920 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 921 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 922 ** to have SQLite generate a 923 ** temporary filename using the same algorithm that is followed to generate 924 ** temporary filenames for TEMP tables and other internal uses. The 925 ** argument should be a char** which will be filled with the filename 926 ** written into memory obtained from [sqlite3_malloc()]. The caller should 927 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 928 ** 929 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 930 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 931 ** maximum number of bytes that will be used for memory-mapped I/O. 932 ** The argument is a pointer to a value of type sqlite3_int64 that 933 ** is an advisory maximum number of bytes in the file to memory map. The 934 ** pointer is overwritten with the old value. The limit is not changed if 935 ** the value originally pointed to is negative, and so the current limit 936 ** can be queried by passing in a pointer to a negative number. This 937 ** file-control is used internally to implement [PRAGMA mmap_size]. 938 ** 939 ** <li>[[SQLITE_FCNTL_TRACE]] 940 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 941 ** to the VFS about what the higher layers of the SQLite stack are doing. 942 ** This file control is used by some VFS activity tracing [shims]. 943 ** The argument is a zero-terminated string. Higher layers in the 944 ** SQLite stack may generate instances of this file control if 945 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 946 ** 947 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 948 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 949 ** pointer to an integer and it writes a boolean into that integer depending 950 ** on whether or not the file has been renamed, moved, or deleted since it 951 ** was first opened. 952 ** 953 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 954 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 955 ** opcode causes the xFileControl method to swap the file handle with the one 956 ** pointed to by the pArg argument. This capability is used during testing 957 ** and only needs to be supported when SQLITE_TEST is defined. 958 ** 959 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 960 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 961 ** be advantageous to block on the next WAL lock if the lock is not immediately 962 ** available. The WAL subsystem issues this signal during rare 963 ** circumstances in order to fix a problem with priority inversion. 964 ** Applications should <em>not</em> use this file-control. 965 ** 966 ** </ul> 967 */ 968 #define SQLITE_FCNTL_LOCKSTATE 1 969 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 970 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 971 #define SQLITE_FCNTL_LAST_ERRNO 4 972 #define SQLITE_FCNTL_SIZE_HINT 5 973 #define SQLITE_FCNTL_CHUNK_SIZE 6 974 #define SQLITE_FCNTL_FILE_POINTER 7 975 #define SQLITE_FCNTL_SYNC_OMITTED 8 976 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 977 #define SQLITE_FCNTL_PERSIST_WAL 10 978 #define SQLITE_FCNTL_OVERWRITE 11 979 #define SQLITE_FCNTL_VFSNAME 12 980 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 981 #define SQLITE_FCNTL_PRAGMA 14 982 #define SQLITE_FCNTL_BUSYHANDLER 15 983 #define SQLITE_FCNTL_TEMPFILENAME 16 984 #define SQLITE_FCNTL_MMAP_SIZE 18 985 #define SQLITE_FCNTL_TRACE 19 986 #define SQLITE_FCNTL_HAS_MOVED 20 987 #define SQLITE_FCNTL_SYNC 21 988 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 989 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 990 #define SQLITE_FCNTL_WAL_BLOCK 24 991 992 /* deprecated names */ 993 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 994 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 995 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 996 997 998 /* 999 ** CAPI3REF: Mutex Handle 1000 ** 1001 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1002 ** abstract type for a mutex object. The SQLite core never looks 1003 ** at the internal representation of an [sqlite3_mutex]. It only 1004 ** deals with pointers to the [sqlite3_mutex] object. 1005 ** 1006 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1007 */ 1008 typedef struct sqlite3_mutex sqlite3_mutex; 1009 1010 /* 1011 ** CAPI3REF: OS Interface Object 1012 ** 1013 ** An instance of the sqlite3_vfs object defines the interface between 1014 ** the SQLite core and the underlying operating system. The "vfs" 1015 ** in the name of the object stands for "virtual file system". See 1016 ** the [VFS | VFS documentation] for further information. 1017 ** 1018 ** The value of the iVersion field is initially 1 but may be larger in 1019 ** future versions of SQLite. Additional fields may be appended to this 1020 ** object when the iVersion value is increased. Note that the structure 1021 ** of the sqlite3_vfs object changes in the transaction between 1022 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1023 ** modified. 1024 ** 1025 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1026 ** structure used by this VFS. mxPathname is the maximum length of 1027 ** a pathname in this VFS. 1028 ** 1029 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1030 ** the pNext pointer. The [sqlite3_vfs_register()] 1031 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1032 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1033 ** searches the list. Neither the application code nor the VFS 1034 ** implementation should use the pNext pointer. 1035 ** 1036 ** The pNext field is the only field in the sqlite3_vfs 1037 ** structure that SQLite will ever modify. SQLite will only access 1038 ** or modify this field while holding a particular static mutex. 1039 ** The application should never modify anything within the sqlite3_vfs 1040 ** object once the object has been registered. 1041 ** 1042 ** The zName field holds the name of the VFS module. The name must 1043 ** be unique across all VFS modules. 1044 ** 1045 ** [[sqlite3_vfs.xOpen]] 1046 ** ^SQLite guarantees that the zFilename parameter to xOpen 1047 ** is either a NULL pointer or string obtained 1048 ** from xFullPathname() with an optional suffix added. 1049 ** ^If a suffix is added to the zFilename parameter, it will 1050 ** consist of a single "-" character followed by no more than 1051 ** 11 alphanumeric and/or "-" characters. 1052 ** ^SQLite further guarantees that 1053 ** the string will be valid and unchanged until xClose() is 1054 ** called. Because of the previous sentence, 1055 ** the [sqlite3_file] can safely store a pointer to the 1056 ** filename if it needs to remember the filename for some reason. 1057 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1058 ** must invent its own temporary name for the file. ^Whenever the 1059 ** xFilename parameter is NULL it will also be the case that the 1060 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1061 ** 1062 ** The flags argument to xOpen() includes all bits set in 1063 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1064 ** or [sqlite3_open16()] is used, then flags includes at least 1065 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1066 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1067 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1068 ** 1069 ** ^(SQLite will also add one of the following flags to the xOpen() 1070 ** call, depending on the object being opened: 1071 ** 1072 ** <ul> 1073 ** <li> [SQLITE_OPEN_MAIN_DB] 1074 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1075 ** <li> [SQLITE_OPEN_TEMP_DB] 1076 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1077 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1078 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1079 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1080 ** <li> [SQLITE_OPEN_WAL] 1081 ** </ul>)^ 1082 ** 1083 ** The file I/O implementation can use the object type flags to 1084 ** change the way it deals with files. For example, an application 1085 ** that does not care about crash recovery or rollback might make 1086 ** the open of a journal file a no-op. Writes to this journal would 1087 ** also be no-ops, and any attempt to read the journal would return 1088 ** SQLITE_IOERR. Or the implementation might recognize that a database 1089 ** file will be doing page-aligned sector reads and writes in a random 1090 ** order and set up its I/O subsystem accordingly. 1091 ** 1092 ** SQLite might also add one of the following flags to the xOpen method: 1093 ** 1094 ** <ul> 1095 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1096 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1097 ** </ul> 1098 ** 1099 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1100 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1101 ** will be set for TEMP databases and their journals, transient 1102 ** databases, and subjournals. 1103 ** 1104 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1105 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1106 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1107 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1108 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1109 ** be created, and that it is an error if it already exists. 1110 ** It is <i>not</i> used to indicate the file should be opened 1111 ** for exclusive access. 1112 ** 1113 ** ^At least szOsFile bytes of memory are allocated by SQLite 1114 ** to hold the [sqlite3_file] structure passed as the third 1115 ** argument to xOpen. The xOpen method does not have to 1116 ** allocate the structure; it should just fill it in. Note that 1117 ** the xOpen method must set the sqlite3_file.pMethods to either 1118 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1119 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1120 ** element will be valid after xOpen returns regardless of the success 1121 ** or failure of the xOpen call. 1122 ** 1123 ** [[sqlite3_vfs.xAccess]] 1124 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1125 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1126 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1127 ** to test whether a file is at least readable. The file can be a 1128 ** directory. 1129 ** 1130 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1131 ** output buffer xFullPathname. The exact size of the output buffer 1132 ** is also passed as a parameter to both methods. If the output buffer 1133 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1134 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1135 ** to prevent this by setting mxPathname to a sufficiently large value. 1136 ** 1137 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1138 ** interfaces are not strictly a part of the filesystem, but they are 1139 ** included in the VFS structure for completeness. 1140 ** The xRandomness() function attempts to return nBytes bytes 1141 ** of good-quality randomness into zOut. The return value is 1142 ** the actual number of bytes of randomness obtained. 1143 ** The xSleep() method causes the calling thread to sleep for at 1144 ** least the number of microseconds given. ^The xCurrentTime() 1145 ** method returns a Julian Day Number for the current date and time as 1146 ** a floating point value. 1147 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1148 ** Day Number multiplied by 86400000 (the number of milliseconds in 1149 ** a 24-hour day). 1150 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1151 ** date and time if that method is available (if iVersion is 2 or 1152 ** greater and the function pointer is not NULL) and will fall back 1153 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1154 ** 1155 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1156 ** are not used by the SQLite core. These optional interfaces are provided 1157 ** by some VFSes to facilitate testing of the VFS code. By overriding 1158 ** system calls with functions under its control, a test program can 1159 ** simulate faults and error conditions that would otherwise be difficult 1160 ** or impossible to induce. The set of system calls that can be overridden 1161 ** varies from one VFS to another, and from one version of the same VFS to the 1162 ** next. Applications that use these interfaces must be prepared for any 1163 ** or all of these interfaces to be NULL or for their behavior to change 1164 ** from one release to the next. Applications must not attempt to access 1165 ** any of these methods if the iVersion of the VFS is less than 3. 1166 */ 1167 typedef struct sqlite3_vfs sqlite3_vfs; 1168 typedef void (*sqlite3_syscall_ptr)(void); 1169 struct sqlite3_vfs { 1170 int iVersion; /* Structure version number (currently 3) */ 1171 int szOsFile; /* Size of subclassed sqlite3_file */ 1172 int mxPathname; /* Maximum file pathname length */ 1173 sqlite3_vfs *pNext; /* Next registered VFS */ 1174 const char *zName; /* Name of this virtual file system */ 1175 void *pAppData; /* Pointer to application-specific data */ 1176 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1177 int flags, int *pOutFlags); 1178 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1179 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1180 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1181 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1182 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1183 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1184 void (*xDlClose)(sqlite3_vfs*, void*); 1185 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1186 int (*xSleep)(sqlite3_vfs*, int microseconds); 1187 int (*xCurrentTime)(sqlite3_vfs*, double*); 1188 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1189 /* 1190 ** The methods above are in version 1 of the sqlite_vfs object 1191 ** definition. Those that follow are added in version 2 or later 1192 */ 1193 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1194 /* 1195 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1196 ** Those below are for version 3 and greater. 1197 */ 1198 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1199 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1200 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1201 /* 1202 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1203 ** New fields may be appended in figure versions. The iVersion 1204 ** value will increment whenever this happens. 1205 */ 1206 }; 1207 1208 /* 1209 ** CAPI3REF: Flags for the xAccess VFS method 1210 ** 1211 ** These integer constants can be used as the third parameter to 1212 ** the xAccess method of an [sqlite3_vfs] object. They determine 1213 ** what kind of permissions the xAccess method is looking for. 1214 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1215 ** simply checks whether the file exists. 1216 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1217 ** checks whether the named directory is both readable and writable 1218 ** (in other words, if files can be added, removed, and renamed within 1219 ** the directory). 1220 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1221 ** [temp_store_directory pragma], though this could change in a future 1222 ** release of SQLite. 1223 ** With SQLITE_ACCESS_READ, the xAccess method 1224 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1225 ** currently unused, though it might be used in a future release of 1226 ** SQLite. 1227 */ 1228 #define SQLITE_ACCESS_EXISTS 0 1229 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1230 #define SQLITE_ACCESS_READ 2 /* Unused */ 1231 1232 /* 1233 ** CAPI3REF: Flags for the xShmLock VFS method 1234 ** 1235 ** These integer constants define the various locking operations 1236 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1237 ** following are the only legal combinations of flags to the 1238 ** xShmLock method: 1239 ** 1240 ** <ul> 1241 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1242 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1243 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1244 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1245 ** </ul> 1246 ** 1247 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1248 ** was given on the corresponding lock. 1249 ** 1250 ** The xShmLock method can transition between unlocked and SHARED or 1251 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1252 ** and EXCLUSIVE. 1253 */ 1254 #define SQLITE_SHM_UNLOCK 1 1255 #define SQLITE_SHM_LOCK 2 1256 #define SQLITE_SHM_SHARED 4 1257 #define SQLITE_SHM_EXCLUSIVE 8 1258 1259 /* 1260 ** CAPI3REF: Maximum xShmLock index 1261 ** 1262 ** The xShmLock method on [sqlite3_io_methods] may use values 1263 ** between 0 and this upper bound as its "offset" argument. 1264 ** The SQLite core will never attempt to acquire or release a 1265 ** lock outside of this range 1266 */ 1267 #define SQLITE_SHM_NLOCK 8 1268 1269 1270 /* 1271 ** CAPI3REF: Initialize The SQLite Library 1272 ** 1273 ** ^The sqlite3_initialize() routine initializes the 1274 ** SQLite library. ^The sqlite3_shutdown() routine 1275 ** deallocates any resources that were allocated by sqlite3_initialize(). 1276 ** These routines are designed to aid in process initialization and 1277 ** shutdown on embedded systems. Workstation applications using 1278 ** SQLite normally do not need to invoke either of these routines. 1279 ** 1280 ** A call to sqlite3_initialize() is an "effective" call if it is 1281 ** the first time sqlite3_initialize() is invoked during the lifetime of 1282 ** the process, or if it is the first time sqlite3_initialize() is invoked 1283 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1284 ** of sqlite3_initialize() does any initialization. All other calls 1285 ** are harmless no-ops.)^ 1286 ** 1287 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1288 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1289 ** an effective call to sqlite3_shutdown() does any deinitialization. 1290 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1291 ** 1292 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1293 ** is not. The sqlite3_shutdown() interface must only be called from a 1294 ** single thread. All open [database connections] must be closed and all 1295 ** other SQLite resources must be deallocated prior to invoking 1296 ** sqlite3_shutdown(). 1297 ** 1298 ** Among other things, ^sqlite3_initialize() will invoke 1299 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1300 ** will invoke sqlite3_os_end(). 1301 ** 1302 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1303 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1304 ** the library (perhaps it is unable to allocate a needed resource such 1305 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1306 ** 1307 ** ^The sqlite3_initialize() routine is called internally by many other 1308 ** SQLite interfaces so that an application usually does not need to 1309 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1310 ** calls sqlite3_initialize() so the SQLite library will be automatically 1311 ** initialized when [sqlite3_open()] is called if it has not be initialized 1312 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1313 ** compile-time option, then the automatic calls to sqlite3_initialize() 1314 ** are omitted and the application must call sqlite3_initialize() directly 1315 ** prior to using any other SQLite interface. For maximum portability, 1316 ** it is recommended that applications always invoke sqlite3_initialize() 1317 ** directly prior to using any other SQLite interface. Future releases 1318 ** of SQLite may require this. In other words, the behavior exhibited 1319 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1320 ** default behavior in some future release of SQLite. 1321 ** 1322 ** The sqlite3_os_init() routine does operating-system specific 1323 ** initialization of the SQLite library. The sqlite3_os_end() 1324 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1325 ** performed by these routines include allocation or deallocation 1326 ** of static resources, initialization of global variables, 1327 ** setting up a default [sqlite3_vfs] module, or setting up 1328 ** a default configuration using [sqlite3_config()]. 1329 ** 1330 ** The application should never invoke either sqlite3_os_init() 1331 ** or sqlite3_os_end() directly. The application should only invoke 1332 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1333 ** interface is called automatically by sqlite3_initialize() and 1334 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1335 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1336 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1337 ** When [custom builds | built for other platforms] 1338 ** (using the [SQLITE_OS_OTHER=1] compile-time 1339 ** option) the application must supply a suitable implementation for 1340 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1341 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1342 ** must return [SQLITE_OK] on success and some other [error code] upon 1343 ** failure. 1344 */ 1345 SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void); 1346 SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void); 1347 SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void); 1348 SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void); 1349 1350 /* 1351 ** CAPI3REF: Configuring The SQLite Library 1352 ** 1353 ** The sqlite3_config() interface is used to make global configuration 1354 ** changes to SQLite in order to tune SQLite to the specific needs of 1355 ** the application. The default configuration is recommended for most 1356 ** applications and so this routine is usually not necessary. It is 1357 ** provided to support rare applications with unusual needs. 1358 ** 1359 ** The sqlite3_config() interface is not threadsafe. The application 1360 ** must insure that no other SQLite interfaces are invoked by other 1361 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1362 ** may only be invoked prior to library initialization using 1363 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1364 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1365 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1366 ** Note, however, that ^sqlite3_config() can be called as part of the 1367 ** implementation of an application-defined [sqlite3_os_init()]. 1368 ** 1369 ** The first argument to sqlite3_config() is an integer 1370 ** [configuration option] that determines 1371 ** what property of SQLite is to be configured. Subsequent arguments 1372 ** vary depending on the [configuration option] 1373 ** in the first argument. 1374 ** 1375 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1376 ** ^If the option is unknown or SQLite is unable to set the option 1377 ** then this routine returns a non-zero [error code]. 1378 */ 1379 SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...); 1380 1381 /* 1382 ** CAPI3REF: Configure database connections 1383 ** METHOD: sqlite3 1384 ** 1385 ** The sqlite3_db_config() interface is used to make configuration 1386 ** changes to a [database connection]. The interface is similar to 1387 ** [sqlite3_config()] except that the changes apply to a single 1388 ** [database connection] (specified in the first argument). 1389 ** 1390 ** The second argument to sqlite3_db_config(D,V,...) is the 1391 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1392 ** that indicates what aspect of the [database connection] is being configured. 1393 ** Subsequent arguments vary depending on the configuration verb. 1394 ** 1395 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1396 ** the call is considered successful. 1397 */ 1398 SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...); 1399 1400 /* 1401 ** CAPI3REF: Memory Allocation Routines 1402 ** 1403 ** An instance of this object defines the interface between SQLite 1404 ** and low-level memory allocation routines. 1405 ** 1406 ** This object is used in only one place in the SQLite interface. 1407 ** A pointer to an instance of this object is the argument to 1408 ** [sqlite3_config()] when the configuration option is 1409 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1410 ** By creating an instance of this object 1411 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1412 ** during configuration, an application can specify an alternative 1413 ** memory allocation subsystem for SQLite to use for all of its 1414 ** dynamic memory needs. 1415 ** 1416 ** Note that SQLite comes with several [built-in memory allocators] 1417 ** that are perfectly adequate for the overwhelming majority of applications 1418 ** and that this object is only useful to a tiny minority of applications 1419 ** with specialized memory allocation requirements. This object is 1420 ** also used during testing of SQLite in order to specify an alternative 1421 ** memory allocator that simulates memory out-of-memory conditions in 1422 ** order to verify that SQLite recovers gracefully from such 1423 ** conditions. 1424 ** 1425 ** The xMalloc, xRealloc, and xFree methods must work like the 1426 ** malloc(), realloc() and free() functions from the standard C library. 1427 ** ^SQLite guarantees that the second argument to 1428 ** xRealloc is always a value returned by a prior call to xRoundup. 1429 ** 1430 ** xSize should return the allocated size of a memory allocation 1431 ** previously obtained from xMalloc or xRealloc. The allocated size 1432 ** is always at least as big as the requested size but may be larger. 1433 ** 1434 ** The xRoundup method returns what would be the allocated size of 1435 ** a memory allocation given a particular requested size. Most memory 1436 ** allocators round up memory allocations at least to the next multiple 1437 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1438 ** Every memory allocation request coming in through [sqlite3_malloc()] 1439 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1440 ** that causes the corresponding memory allocation to fail. 1441 ** 1442 ** The xInit method initializes the memory allocator. For example, 1443 ** it might allocate any require mutexes or initialize internal data 1444 ** structures. The xShutdown method is invoked (indirectly) by 1445 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1446 ** by xInit. The pAppData pointer is used as the only parameter to 1447 ** xInit and xShutdown. 1448 ** 1449 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1450 ** the xInit method, so the xInit method need not be threadsafe. The 1451 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1452 ** not need to be threadsafe either. For all other methods, SQLite 1453 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1454 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1455 ** it is by default) and so the methods are automatically serialized. 1456 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1457 ** methods must be threadsafe or else make their own arrangements for 1458 ** serialization. 1459 ** 1460 ** SQLite will never invoke xInit() more than once without an intervening 1461 ** call to xShutdown(). 1462 */ 1463 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1464 struct sqlite3_mem_methods { 1465 void *(*xMalloc)(int); /* Memory allocation function */ 1466 void (*xFree)(void*); /* Free a prior allocation */ 1467 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1468 int (*xSize)(void*); /* Return the size of an allocation */ 1469 int (*xRoundup)(int); /* Round up request size to allocation size */ 1470 int (*xInit)(void*); /* Initialize the memory allocator */ 1471 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1472 void *pAppData; /* Argument to xInit() and xShutdown() */ 1473 }; 1474 1475 /* 1476 ** CAPI3REF: Configuration Options 1477 ** KEYWORDS: {configuration option} 1478 ** 1479 ** These constants are the available integer configuration options that 1480 ** can be passed as the first argument to the [sqlite3_config()] interface. 1481 ** 1482 ** New configuration options may be added in future releases of SQLite. 1483 ** Existing configuration options might be discontinued. Applications 1484 ** should check the return code from [sqlite3_config()] to make sure that 1485 ** the call worked. The [sqlite3_config()] interface will return a 1486 ** non-zero [error code] if a discontinued or unsupported configuration option 1487 ** is invoked. 1488 ** 1489 ** <dl> 1490 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1491 ** <dd>There are no arguments to this option. ^This option sets the 1492 ** [threading mode] to Single-thread. In other words, it disables 1493 ** all mutexing and puts SQLite into a mode where it can only be used 1494 ** by a single thread. ^If SQLite is compiled with 1495 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1496 ** it is not possible to change the [threading mode] from its default 1497 ** value of Single-thread and so [sqlite3_config()] will return 1498 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1499 ** configuration option.</dd> 1500 ** 1501 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1502 ** <dd>There are no arguments to this option. ^This option sets the 1503 ** [threading mode] to Multi-thread. In other words, it disables 1504 ** mutexing on [database connection] and [prepared statement] objects. 1505 ** The application is responsible for serializing access to 1506 ** [database connections] and [prepared statements]. But other mutexes 1507 ** are enabled so that SQLite will be safe to use in a multi-threaded 1508 ** environment as long as no two threads attempt to use the same 1509 ** [database connection] at the same time. ^If SQLite is compiled with 1510 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1511 ** it is not possible to set the Multi-thread [threading mode] and 1512 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1513 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1514 ** 1515 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1516 ** <dd>There are no arguments to this option. ^This option sets the 1517 ** [threading mode] to Serialized. In other words, this option enables 1518 ** all mutexes including the recursive 1519 ** mutexes on [database connection] and [prepared statement] objects. 1520 ** In this mode (which is the default when SQLite is compiled with 1521 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1522 ** to [database connections] and [prepared statements] so that the 1523 ** application is free to use the same [database connection] or the 1524 ** same [prepared statement] in different threads at the same time. 1525 ** ^If SQLite is compiled with 1526 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1527 ** it is not possible to set the Serialized [threading mode] and 1528 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1529 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1530 ** 1531 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1532 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1533 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1534 ** The argument specifies 1535 ** alternative low-level memory allocation routines to be used in place of 1536 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1537 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1538 ** before the [sqlite3_config()] call returns.</dd> 1539 ** 1540 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1541 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1542 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1543 ** The [sqlite3_mem_methods] 1544 ** structure is filled with the currently defined memory allocation routines.)^ 1545 ** This option can be used to overload the default memory allocation 1546 ** routines with a wrapper that simulations memory allocation failure or 1547 ** tracks memory usage, for example. </dd> 1548 ** 1549 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1550 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1551 ** interpreted as a boolean, which enables or disables the collection of 1552 ** memory allocation statistics. ^(When memory allocation statistics are 1553 ** disabled, the following SQLite interfaces become non-operational: 1554 ** <ul> 1555 ** <li> [sqlite3_memory_used()] 1556 ** <li> [sqlite3_memory_highwater()] 1557 ** <li> [sqlite3_soft_heap_limit64()] 1558 ** <li> [sqlite3_status64()] 1559 ** </ul>)^ 1560 ** ^Memory allocation statistics are enabled by default unless SQLite is 1561 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1562 ** allocation statistics are disabled by default. 1563 ** </dd> 1564 ** 1565 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1566 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1567 ** that SQLite can use for scratch memory. ^(There are three arguments 1568 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1569 ** aligned memory buffer from which the scratch allocations will be 1570 ** drawn, the size of each scratch allocation (sz), 1571 ** and the maximum number of scratch allocations (N).)^ 1572 ** The first argument must be a pointer to an 8-byte aligned buffer 1573 ** of at least sz*N bytes of memory. 1574 ** ^SQLite will not use more than one scratch buffers per thread. 1575 ** ^SQLite will never request a scratch buffer that is more than 6 1576 ** times the database page size. 1577 ** ^If SQLite needs needs additional 1578 ** scratch memory beyond what is provided by this configuration option, then 1579 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1580 ** ^When the application provides any amount of scratch memory using 1581 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1582 ** [sqlite3_malloc|heap allocations]. 1583 ** This can help [Robson proof|prevent memory allocation failures] due to heap 1584 ** fragmentation in low-memory embedded systems. 1585 ** </dd> 1586 ** 1587 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1588 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer 1589 ** that SQLite can use for the database page cache with the default page 1590 ** cache implementation. 1591 ** This configuration should not be used if an application-define page 1592 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2] 1593 ** configuration option. 1594 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1595 ** 8-byte aligned 1596 ** memory, the size of each page buffer (sz), and the number of pages (N). 1597 ** The sz argument should be the size of the largest database page 1598 ** (a power of two between 512 and 65536) plus some extra bytes for each 1599 ** page header. ^The number of extra bytes needed by the page header 1600 ** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option 1601 ** to [sqlite3_config()]. 1602 ** ^It is harmless, apart from the wasted memory, 1603 ** for the sz parameter to be larger than necessary. The first 1604 ** argument should pointer to an 8-byte aligned block of memory that 1605 ** is at least sz*N bytes of memory, otherwise subsequent behavior is 1606 ** undefined. 1607 ** ^SQLite will use the memory provided by the first argument to satisfy its 1608 ** memory needs for the first N pages that it adds to cache. ^If additional 1609 ** page cache memory is needed beyond what is provided by this option, then 1610 ** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd> 1611 ** 1612 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1613 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1614 ** that SQLite will use for all of its dynamic memory allocation needs 1615 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1616 ** [SQLITE_CONFIG_PAGECACHE]. 1617 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1618 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1619 ** [SQLITE_ERROR] if invoked otherwise. 1620 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1621 ** An 8-byte aligned pointer to the memory, 1622 ** the number of bytes in the memory buffer, and the minimum allocation size. 1623 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1624 ** to using its default memory allocator (the system malloc() implementation), 1625 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1626 ** memory pointer is not NULL then the alternative memory 1627 ** allocator is engaged to handle all of SQLites memory allocation needs. 1628 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1629 ** boundary or subsequent behavior of SQLite will be undefined. 1630 ** The minimum allocation size is capped at 2**12. Reasonable values 1631 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1632 ** 1633 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1634 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1635 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1636 ** The argument specifies alternative low-level mutex routines to be used 1637 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1638 ** the content of the [sqlite3_mutex_methods] structure before the call to 1639 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1640 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1641 ** the entire mutexing subsystem is omitted from the build and hence calls to 1642 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1643 ** return [SQLITE_ERROR].</dd> 1644 ** 1645 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1646 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1647 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1648 ** [sqlite3_mutex_methods] 1649 ** structure is filled with the currently defined mutex routines.)^ 1650 ** This option can be used to overload the default mutex allocation 1651 ** routines with a wrapper used to track mutex usage for performance 1652 ** profiling or testing, for example. ^If SQLite is compiled with 1653 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1654 ** the entire mutexing subsystem is omitted from the build and hence calls to 1655 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1656 ** return [SQLITE_ERROR].</dd> 1657 ** 1658 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1659 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1660 ** the default size of lookaside memory on each [database connection]. 1661 ** The first argument is the 1662 ** size of each lookaside buffer slot and the second is the number of 1663 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1664 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1665 ** option to [sqlite3_db_config()] can be used to change the lookaside 1666 ** configuration on individual connections.)^ </dd> 1667 ** 1668 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1669 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1670 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1671 ** the interface to a custom page cache implementation.)^ 1672 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1673 ** 1674 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1675 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1676 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1677 ** the current page cache implementation into that object.)^ </dd> 1678 ** 1679 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1680 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1681 ** global [error log]. 1682 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1683 ** function with a call signature of void(*)(void*,int,const char*), 1684 ** and a pointer to void. ^If the function pointer is not NULL, it is 1685 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1686 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1687 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1688 ** passed through as the first parameter to the application-defined logger 1689 ** function whenever that function is invoked. ^The second parameter to 1690 ** the logger function is a copy of the first parameter to the corresponding 1691 ** [sqlite3_log()] call and is intended to be a [result code] or an 1692 ** [extended result code]. ^The third parameter passed to the logger is 1693 ** log message after formatting via [sqlite3_snprintf()]. 1694 ** The SQLite logging interface is not reentrant; the logger function 1695 ** supplied by the application must not invoke any SQLite interface. 1696 ** In a multi-threaded application, the application-defined logger 1697 ** function must be threadsafe. </dd> 1698 ** 1699 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1700 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1701 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1702 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1703 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1704 ** [sqlite3_open16()] or 1705 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1706 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1707 ** connection is opened. ^If it is globally disabled, filenames are 1708 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1709 ** database connection is opened. ^(By default, URI handling is globally 1710 ** disabled. The default value may be changed by compiling with the 1711 ** [SQLITE_USE_URI] symbol defined.)^ 1712 ** 1713 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1714 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1715 ** argument which is interpreted as a boolean in order to enable or disable 1716 ** the use of covering indices for full table scans in the query optimizer. 1717 ** ^The default setting is determined 1718 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1719 ** if that compile-time option is omitted. 1720 ** The ability to disable the use of covering indices for full table scans 1721 ** is because some incorrectly coded legacy applications might malfunction 1722 ** when the optimization is enabled. Providing the ability to 1723 ** disable the optimization allows the older, buggy application code to work 1724 ** without change even with newer versions of SQLite. 1725 ** 1726 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1727 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1728 ** <dd> These options are obsolete and should not be used by new code. 1729 ** They are retained for backwards compatibility but are now no-ops. 1730 ** </dd> 1731 ** 1732 ** [[SQLITE_CONFIG_SQLLOG]] 1733 ** <dt>SQLITE_CONFIG_SQLLOG 1734 ** <dd>This option is only available if sqlite is compiled with the 1735 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1736 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1737 ** The second should be of type (void*). The callback is invoked by the library 1738 ** in three separate circumstances, identified by the value passed as the 1739 ** fourth parameter. If the fourth parameter is 0, then the database connection 1740 ** passed as the second argument has just been opened. The third argument 1741 ** points to a buffer containing the name of the main database file. If the 1742 ** fourth parameter is 1, then the SQL statement that the third parameter 1743 ** points to has just been executed. Or, if the fourth parameter is 2, then 1744 ** the connection being passed as the second parameter is being closed. The 1745 ** third parameter is passed NULL In this case. An example of using this 1746 ** configuration option can be seen in the "test_sqllog.c" source file in 1747 ** the canonical SQLite source tree.</dd> 1748 ** 1749 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1750 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1751 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1752 ** that are the default mmap size limit (the default setting for 1753 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1754 ** ^The default setting can be overridden by each database connection using 1755 ** either the [PRAGMA mmap_size] command, or by using the 1756 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1757 ** will be silently truncated if necessary so that it does not exceed the 1758 ** compile-time maximum mmap size set by the 1759 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1760 ** ^If either argument to this option is negative, then that argument is 1761 ** changed to its compile-time default. 1762 ** 1763 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1764 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1765 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1766 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1767 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1768 ** that specifies the maximum size of the created heap. 1769 ** 1770 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1771 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1772 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1773 ** is a pointer to an integer and writes into that integer the number of extra 1774 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1775 ** The amount of extra space required can change depending on the compiler, 1776 ** target platform, and SQLite version. 1777 ** 1778 ** [[SQLITE_CONFIG_PMASZ]] 1779 ** <dt>SQLITE_CONFIG_PMASZ 1780 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1781 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1782 ** sorter to that integer. The default minimum PMA Size is set by the 1783 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1784 ** to help with sort operations when multithreaded sorting 1785 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1786 ** to be sorted exceeds the page size times the minimum of the 1787 ** [PRAGMA cache_size] setting and this value. 1788 ** </dl> 1789 */ 1790 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1791 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1792 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1793 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1794 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1795 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1796 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1797 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1798 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1799 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1800 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1801 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1802 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1803 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1804 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1805 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1806 #define SQLITE_CONFIG_URI 17 /* int */ 1807 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1808 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1809 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1810 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1811 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1812 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1813 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1814 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1815 1816 /* 1817 ** CAPI3REF: Database Connection Configuration Options 1818 ** 1819 ** These constants are the available integer configuration options that 1820 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1821 ** 1822 ** New configuration options may be added in future releases of SQLite. 1823 ** Existing configuration options might be discontinued. Applications 1824 ** should check the return code from [sqlite3_db_config()] to make sure that 1825 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1826 ** non-zero [error code] if a discontinued or unsupported configuration option 1827 ** is invoked. 1828 ** 1829 ** <dl> 1830 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1831 ** <dd> ^This option takes three additional arguments that determine the 1832 ** [lookaside memory allocator] configuration for the [database connection]. 1833 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1834 ** pointer to a memory buffer to use for lookaside memory. 1835 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1836 ** may be NULL in which case SQLite will allocate the 1837 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1838 ** size of each lookaside buffer slot. ^The third argument is the number of 1839 ** slots. The size of the buffer in the first argument must be greater than 1840 ** or equal to the product of the second and third arguments. The buffer 1841 ** must be aligned to an 8-byte boundary. ^If the second argument to 1842 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1843 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1844 ** configuration for a database connection can only be changed when that 1845 ** connection is not currently using lookaside memory, or in other words 1846 ** when the "current value" returned by 1847 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1848 ** Any attempt to change the lookaside memory configuration when lookaside 1849 ** memory is in use leaves the configuration unchanged and returns 1850 ** [SQLITE_BUSY].)^</dd> 1851 ** 1852 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1853 ** <dd> ^This option is used to enable or disable the enforcement of 1854 ** [foreign key constraints]. There should be two additional arguments. 1855 ** The first argument is an integer which is 0 to disable FK enforcement, 1856 ** positive to enable FK enforcement or negative to leave FK enforcement 1857 ** unchanged. The second parameter is a pointer to an integer into which 1858 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1859 ** following this call. The second parameter may be a NULL pointer, in 1860 ** which case the FK enforcement setting is not reported back. </dd> 1861 ** 1862 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1863 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1864 ** There should be two additional arguments. 1865 ** The first argument is an integer which is 0 to disable triggers, 1866 ** positive to enable triggers or negative to leave the setting unchanged. 1867 ** The second parameter is a pointer to an integer into which 1868 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1869 ** following this call. The second parameter may be a NULL pointer, in 1870 ** which case the trigger setting is not reported back. </dd> 1871 ** 1872 ** </dl> 1873 */ 1874 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1875 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1876 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1877 1878 1879 /* 1880 ** CAPI3REF: Enable Or Disable Extended Result Codes 1881 ** METHOD: sqlite3 1882 ** 1883 ** ^The sqlite3_extended_result_codes() routine enables or disables the 1884 ** [extended result codes] feature of SQLite. ^The extended result 1885 ** codes are disabled by default for historical compatibility. 1886 */ 1887 SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff); 1888 1889 /* 1890 ** CAPI3REF: Last Insert Rowid 1891 ** METHOD: sqlite3 1892 ** 1893 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1894 ** has a unique 64-bit signed 1895 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1896 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1897 ** names are not also used by explicitly declared columns. ^If 1898 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 1899 ** is another alias for the rowid. 1900 ** 1901 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1902 ** most recent successful [INSERT] into a rowid table or [virtual table] 1903 ** on database connection D. 1904 ** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1905 ** ^If no successful [INSERT]s into rowid tables 1906 ** have ever occurred on the database connection D, 1907 ** then sqlite3_last_insert_rowid(D) returns zero. 1908 ** 1909 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1910 ** method, then this routine will return the [rowid] of the inserted 1911 ** row as long as the trigger or virtual table method is running. 1912 ** But once the trigger or virtual table method ends, the value returned 1913 ** by this routine reverts to what it was before the trigger or virtual 1914 ** table method began.)^ 1915 ** 1916 ** ^An [INSERT] that fails due to a constraint violation is not a 1917 ** successful [INSERT] and does not change the value returned by this 1918 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1919 ** and INSERT OR ABORT make no changes to the return value of this 1920 ** routine when their insertion fails. ^(When INSERT OR REPLACE 1921 ** encounters a constraint violation, it does not fail. The 1922 ** INSERT continues to completion after deleting rows that caused 1923 ** the constraint problem so INSERT OR REPLACE will always change 1924 ** the return value of this interface.)^ 1925 ** 1926 ** ^For the purposes of this routine, an [INSERT] is considered to 1927 ** be successful even if it is subsequently rolled back. 1928 ** 1929 ** This function is accessible to SQL statements via the 1930 ** [last_insert_rowid() SQL function]. 1931 ** 1932 ** If a separate thread performs a new [INSERT] on the same 1933 ** database connection while the [sqlite3_last_insert_rowid()] 1934 ** function is running and thus changes the last insert [rowid], 1935 ** then the value returned by [sqlite3_last_insert_rowid()] is 1936 ** unpredictable and might not equal either the old or the new 1937 ** last insert [rowid]. 1938 */ 1939 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*); 1940 1941 /* 1942 ** CAPI3REF: Count The Number Of Rows Modified 1943 ** METHOD: sqlite3 1944 ** 1945 ** ^This function returns the number of rows modified, inserted or 1946 ** deleted by the most recently completed INSERT, UPDATE or DELETE 1947 ** statement on the database connection specified by the only parameter. 1948 ** ^Executing any other type of SQL statement does not modify the value 1949 ** returned by this function. 1950 ** 1951 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 1952 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 1953 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 1954 ** 1955 ** Changes to a view that are intercepted by 1956 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 1957 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 1958 ** DELETE statement run on a view is always zero. Only changes made to real 1959 ** tables are counted. 1960 ** 1961 ** Things are more complicated if the sqlite3_changes() function is 1962 ** executed while a trigger program is running. This may happen if the 1963 ** program uses the [changes() SQL function], or if some other callback 1964 ** function invokes sqlite3_changes() directly. Essentially: 1965 ** 1966 ** <ul> 1967 ** <li> ^(Before entering a trigger program the value returned by 1968 ** sqlite3_changes() function is saved. After the trigger program 1969 ** has finished, the original value is restored.)^ 1970 ** 1971 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 1972 ** statement sets the value returned by sqlite3_changes() 1973 ** upon completion as normal. Of course, this value will not include 1974 ** any changes performed by sub-triggers, as the sqlite3_changes() 1975 ** value will be saved and restored after each sub-trigger has run.)^ 1976 ** </ul> 1977 ** 1978 ** ^This means that if the changes() SQL function (or similar) is used 1979 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 1980 ** returns the value as set when the calling statement began executing. 1981 ** ^If it is used by the second or subsequent such statement within a trigger 1982 ** program, the value returned reflects the number of rows modified by the 1983 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 1984 ** 1985 ** See also the [sqlite3_total_changes()] interface, the 1986 ** [count_changes pragma], and the [changes() SQL function]. 1987 ** 1988 ** If a separate thread makes changes on the same database connection 1989 ** while [sqlite3_changes()] is running then the value returned 1990 ** is unpredictable and not meaningful. 1991 */ 1992 SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*); 1993 1994 /* 1995 ** CAPI3REF: Total Number Of Rows Modified 1996 ** METHOD: sqlite3 1997 ** 1998 ** ^This function returns the total number of rows inserted, modified or 1999 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2000 ** since the database connection was opened, including those executed as 2001 ** part of trigger programs. ^Executing any other type of SQL statement 2002 ** does not affect the value returned by sqlite3_total_changes(). 2003 ** 2004 ** ^Changes made as part of [foreign key actions] are included in the 2005 ** count, but those made as part of REPLACE constraint resolution are 2006 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2007 ** are not counted. 2008 ** 2009 ** See also the [sqlite3_changes()] interface, the 2010 ** [count_changes pragma], and the [total_changes() SQL function]. 2011 ** 2012 ** If a separate thread makes changes on the same database connection 2013 ** while [sqlite3_total_changes()] is running then the value 2014 ** returned is unpredictable and not meaningful. 2015 */ 2016 SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*); 2017 2018 /* 2019 ** CAPI3REF: Interrupt A Long-Running Query 2020 ** METHOD: sqlite3 2021 ** 2022 ** ^This function causes any pending database operation to abort and 2023 ** return at its earliest opportunity. This routine is typically 2024 ** called in response to a user action such as pressing "Cancel" 2025 ** or Ctrl-C where the user wants a long query operation to halt 2026 ** immediately. 2027 ** 2028 ** ^It is safe to call this routine from a thread different from the 2029 ** thread that is currently running the database operation. But it 2030 ** is not safe to call this routine with a [database connection] that 2031 ** is closed or might close before sqlite3_interrupt() returns. 2032 ** 2033 ** ^If an SQL operation is very nearly finished at the time when 2034 ** sqlite3_interrupt() is called, then it might not have an opportunity 2035 ** to be interrupted and might continue to completion. 2036 ** 2037 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2038 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2039 ** that is inside an explicit transaction, then the entire transaction 2040 ** will be rolled back automatically. 2041 ** 2042 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2043 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2044 ** that are started after the sqlite3_interrupt() call and before the 2045 ** running statements reaches zero are interrupted as if they had been 2046 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2047 ** that are started after the running statement count reaches zero are 2048 ** not effected by the sqlite3_interrupt(). 2049 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2050 ** SQL statements is a no-op and has no effect on SQL statements 2051 ** that are started after the sqlite3_interrupt() call returns. 2052 ** 2053 ** If the database connection closes while [sqlite3_interrupt()] 2054 ** is running then bad things will likely happen. 2055 */ 2056 SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*); 2057 2058 /* 2059 ** CAPI3REF: Determine If An SQL Statement Is Complete 2060 ** 2061 ** These routines are useful during command-line input to determine if the 2062 ** currently entered text seems to form a complete SQL statement or 2063 ** if additional input is needed before sending the text into 2064 ** SQLite for parsing. ^These routines return 1 if the input string 2065 ** appears to be a complete SQL statement. ^A statement is judged to be 2066 ** complete if it ends with a semicolon token and is not a prefix of a 2067 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2068 ** string literals or quoted identifier names or comments are not 2069 ** independent tokens (they are part of the token in which they are 2070 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2071 ** and comments that follow the final semicolon are ignored. 2072 ** 2073 ** ^These routines return 0 if the statement is incomplete. ^If a 2074 ** memory allocation fails, then SQLITE_NOMEM is returned. 2075 ** 2076 ** ^These routines do not parse the SQL statements thus 2077 ** will not detect syntactically incorrect SQL. 2078 ** 2079 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2080 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2081 ** automatically by sqlite3_complete16(). If that initialization fails, 2082 ** then the return value from sqlite3_complete16() will be non-zero 2083 ** regardless of whether or not the input SQL is complete.)^ 2084 ** 2085 ** The input to [sqlite3_complete()] must be a zero-terminated 2086 ** UTF-8 string. 2087 ** 2088 ** The input to [sqlite3_complete16()] must be a zero-terminated 2089 ** UTF-16 string in native byte order. 2090 */ 2091 SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql); 2092 SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql); 2093 2094 /* 2095 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2096 ** KEYWORDS: {busy-handler callback} {busy handler} 2097 ** METHOD: sqlite3 2098 ** 2099 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2100 ** that might be invoked with argument P whenever 2101 ** an attempt is made to access a database table associated with 2102 ** [database connection] D when another thread 2103 ** or process has the table locked. 2104 ** The sqlite3_busy_handler() interface is used to implement 2105 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2106 ** 2107 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2108 ** is returned immediately upon encountering the lock. ^If the busy callback 2109 ** is not NULL, then the callback might be invoked with two arguments. 2110 ** 2111 ** ^The first argument to the busy handler is a copy of the void* pointer which 2112 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2113 ** the busy handler callback is the number of times that the busy handler has 2114 ** been invoked previously for the same locking event. ^If the 2115 ** busy callback returns 0, then no additional attempts are made to 2116 ** access the database and [SQLITE_BUSY] is returned 2117 ** to the application. 2118 ** ^If the callback returns non-zero, then another attempt 2119 ** is made to access the database and the cycle repeats. 2120 ** 2121 ** The presence of a busy handler does not guarantee that it will be invoked 2122 ** when there is lock contention. ^If SQLite determines that invoking the busy 2123 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2124 ** to the application instead of invoking the 2125 ** busy handler. 2126 ** Consider a scenario where one process is holding a read lock that 2127 ** it is trying to promote to a reserved lock and 2128 ** a second process is holding a reserved lock that it is trying 2129 ** to promote to an exclusive lock. The first process cannot proceed 2130 ** because it is blocked by the second and the second process cannot 2131 ** proceed because it is blocked by the first. If both processes 2132 ** invoke the busy handlers, neither will make any progress. Therefore, 2133 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2134 ** will induce the first process to release its read lock and allow 2135 ** the second process to proceed. 2136 ** 2137 ** ^The default busy callback is NULL. 2138 ** 2139 ** ^(There can only be a single busy handler defined for each 2140 ** [database connection]. Setting a new busy handler clears any 2141 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2142 ** or evaluating [PRAGMA busy_timeout=N] will change the 2143 ** busy handler and thus clear any previously set busy handler. 2144 ** 2145 ** The busy callback should not take any actions which modify the 2146 ** database connection that invoked the busy handler. In other words, 2147 ** the busy handler is not reentrant. Any such actions 2148 ** result in undefined behavior. 2149 ** 2150 ** A busy handler must not close the database connection 2151 ** or [prepared statement] that invoked the busy handler. 2152 */ 2153 SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2154 2155 /* 2156 ** CAPI3REF: Set A Busy Timeout 2157 ** METHOD: sqlite3 2158 ** 2159 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2160 ** for a specified amount of time when a table is locked. ^The handler 2161 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2162 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2163 ** the handler returns 0 which causes [sqlite3_step()] to return 2164 ** [SQLITE_BUSY]. 2165 ** 2166 ** ^Calling this routine with an argument less than or equal to zero 2167 ** turns off all busy handlers. 2168 ** 2169 ** ^(There can only be a single busy handler for a particular 2170 ** [database connection] at any given moment. If another busy handler 2171 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2172 ** this routine, that other busy handler is cleared.)^ 2173 ** 2174 ** See also: [PRAGMA busy_timeout] 2175 */ 2176 SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms); 2177 2178 /* 2179 ** CAPI3REF: Convenience Routines For Running Queries 2180 ** METHOD: sqlite3 2181 ** 2182 ** This is a legacy interface that is preserved for backwards compatibility. 2183 ** Use of this interface is not recommended. 2184 ** 2185 ** Definition: A <b>result table</b> is memory data structure created by the 2186 ** [sqlite3_get_table()] interface. A result table records the 2187 ** complete query results from one or more queries. 2188 ** 2189 ** The table conceptually has a number of rows and columns. But 2190 ** these numbers are not part of the result table itself. These 2191 ** numbers are obtained separately. Let N be the number of rows 2192 ** and M be the number of columns. 2193 ** 2194 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2195 ** There are (N+1)*M elements in the array. The first M pointers point 2196 ** to zero-terminated strings that contain the names of the columns. 2197 ** The remaining entries all point to query results. NULL values result 2198 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2199 ** string representation as returned by [sqlite3_column_text()]. 2200 ** 2201 ** A result table might consist of one or more memory allocations. 2202 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2203 ** A result table should be deallocated using [sqlite3_free_table()]. 2204 ** 2205 ** ^(As an example of the result table format, suppose a query result 2206 ** is as follows: 2207 ** 2208 ** <blockquote><pre> 2209 ** Name | Age 2210 ** ----------------------- 2211 ** Alice | 43 2212 ** Bob | 28 2213 ** Cindy | 21 2214 ** </pre></blockquote> 2215 ** 2216 ** There are two column (M==2) and three rows (N==3). Thus the 2217 ** result table has 8 entries. Suppose the result table is stored 2218 ** in an array names azResult. Then azResult holds this content: 2219 ** 2220 ** <blockquote><pre> 2221 ** azResult[0] = "Name"; 2222 ** azResult[1] = "Age"; 2223 ** azResult[2] = "Alice"; 2224 ** azResult[3] = "43"; 2225 ** azResult[4] = "Bob"; 2226 ** azResult[5] = "28"; 2227 ** azResult[6] = "Cindy"; 2228 ** azResult[7] = "21"; 2229 ** </pre></blockquote>)^ 2230 ** 2231 ** ^The sqlite3_get_table() function evaluates one or more 2232 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2233 ** string of its 2nd parameter and returns a result table to the 2234 ** pointer given in its 3rd parameter. 2235 ** 2236 ** After the application has finished with the result from sqlite3_get_table(), 2237 ** it must pass the result table pointer to sqlite3_free_table() in order to 2238 ** release the memory that was malloced. Because of the way the 2239 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2240 ** function must not try to call [sqlite3_free()] directly. Only 2241 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2242 ** 2243 ** The sqlite3_get_table() interface is implemented as a wrapper around 2244 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2245 ** to any internal data structures of SQLite. It uses only the public 2246 ** interface defined here. As a consequence, errors that occur in the 2247 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2248 ** reflected in subsequent calls to [sqlite3_errcode()] or 2249 ** [sqlite3_errmsg()]. 2250 */ 2251 SQLITE_API int SQLITE_STDCALL sqlite3_get_table( 2252 sqlite3 *db, /* An open database */ 2253 const char *zSql, /* SQL to be evaluated */ 2254 char ***pazResult, /* Results of the query */ 2255 int *pnRow, /* Number of result rows written here */ 2256 int *pnColumn, /* Number of result columns written here */ 2257 char **pzErrmsg /* Error msg written here */ 2258 ); 2259 SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result); 2260 2261 /* 2262 ** CAPI3REF: Formatted String Printing Functions 2263 ** 2264 ** These routines are work-alikes of the "printf()" family of functions 2265 ** from the standard C library. 2266 ** These routines understand most of the common K&R formatting options, 2267 ** plus some additional non-standard formats, detailed below. 2268 ** Note that some of the more obscure formatting options from recent 2269 ** C-library standards are omitted from this implementation. 2270 ** 2271 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2272 ** results into memory obtained from [sqlite3_malloc()]. 2273 ** The strings returned by these two routines should be 2274 ** released by [sqlite3_free()]. ^Both routines return a 2275 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2276 ** memory to hold the resulting string. 2277 ** 2278 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2279 ** the standard C library. The result is written into the 2280 ** buffer supplied as the second parameter whose size is given by 2281 ** the first parameter. Note that the order of the 2282 ** first two parameters is reversed from snprintf().)^ This is an 2283 ** historical accident that cannot be fixed without breaking 2284 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2285 ** returns a pointer to its buffer instead of the number of 2286 ** characters actually written into the buffer.)^ We admit that 2287 ** the number of characters written would be a more useful return 2288 ** value but we cannot change the implementation of sqlite3_snprintf() 2289 ** now without breaking compatibility. 2290 ** 2291 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2292 ** guarantees that the buffer is always zero-terminated. ^The first 2293 ** parameter "n" is the total size of the buffer, including space for 2294 ** the zero terminator. So the longest string that can be completely 2295 ** written will be n-1 characters. 2296 ** 2297 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2298 ** 2299 ** These routines all implement some additional formatting 2300 ** options that are useful for constructing SQL statements. 2301 ** All of the usual printf() formatting options apply. In addition, there 2302 ** is are "%q", "%Q", "%w" and "%z" options. 2303 ** 2304 ** ^(The %q option works like %s in that it substitutes a nul-terminated 2305 ** string from the argument list. But %q also doubles every '\'' character. 2306 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2307 ** character it escapes that character and allows it to be inserted into 2308 ** the string. 2309 ** 2310 ** For example, assume the string variable zText contains text as follows: 2311 ** 2312 ** <blockquote><pre> 2313 ** char *zText = "It's a happy day!"; 2314 ** </pre></blockquote> 2315 ** 2316 ** One can use this text in an SQL statement as follows: 2317 ** 2318 ** <blockquote><pre> 2319 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2320 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2321 ** sqlite3_free(zSQL); 2322 ** </pre></blockquote> 2323 ** 2324 ** Because the %q format string is used, the '\'' character in zText 2325 ** is escaped and the SQL generated is as follows: 2326 ** 2327 ** <blockquote><pre> 2328 ** INSERT INTO table1 VALUES('It''s a happy day!') 2329 ** </pre></blockquote> 2330 ** 2331 ** This is correct. Had we used %s instead of %q, the generated SQL 2332 ** would have looked like this: 2333 ** 2334 ** <blockquote><pre> 2335 ** INSERT INTO table1 VALUES('It's a happy day!'); 2336 ** </pre></blockquote> 2337 ** 2338 ** This second example is an SQL syntax error. As a general rule you should 2339 ** always use %q instead of %s when inserting text into a string literal. 2340 ** 2341 ** ^(The %Q option works like %q except it also adds single quotes around 2342 ** the outside of the total string. Additionally, if the parameter in the 2343 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2344 ** single quotes).)^ So, for example, one could say: 2345 ** 2346 ** <blockquote><pre> 2347 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2348 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2349 ** sqlite3_free(zSQL); 2350 ** </pre></blockquote> 2351 ** 2352 ** The code above will render a correct SQL statement in the zSQL 2353 ** variable even if the zText variable is a NULL pointer. 2354 ** 2355 ** ^(The "%w" formatting option is like "%q" except that it expects to 2356 ** be contained within double-quotes instead of single quotes, and it 2357 ** escapes the double-quote character instead of the single-quote 2358 ** character.)^ The "%w" formatting option is intended for safely inserting 2359 ** table and column names into a constructed SQL statement. 2360 ** 2361 ** ^(The "%z" formatting option works like "%s" but with the 2362 ** addition that after the string has been read and copied into 2363 ** the result, [sqlite3_free()] is called on the input string.)^ 2364 */ 2365 SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...); 2366 SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list); 2367 SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...); 2368 SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list); 2369 2370 /* 2371 ** CAPI3REF: Memory Allocation Subsystem 2372 ** 2373 ** The SQLite core uses these three routines for all of its own 2374 ** internal memory allocation needs. "Core" in the previous sentence 2375 ** does not include operating-system specific VFS implementation. The 2376 ** Windows VFS uses native malloc() and free() for some operations. 2377 ** 2378 ** ^The sqlite3_malloc() routine returns a pointer to a block 2379 ** of memory at least N bytes in length, where N is the parameter. 2380 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2381 ** memory, it returns a NULL pointer. ^If the parameter N to 2382 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2383 ** a NULL pointer. 2384 ** 2385 ** ^The sqlite3_malloc64(N) routine works just like 2386 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2387 ** of a signed 32-bit integer. 2388 ** 2389 ** ^Calling sqlite3_free() with a pointer previously returned 2390 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2391 ** that it might be reused. ^The sqlite3_free() routine is 2392 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2393 ** to sqlite3_free() is harmless. After being freed, memory 2394 ** should neither be read nor written. Even reading previously freed 2395 ** memory might result in a segmentation fault or other severe error. 2396 ** Memory corruption, a segmentation fault, or other severe error 2397 ** might result if sqlite3_free() is called with a non-NULL pointer that 2398 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2399 ** 2400 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2401 ** prior memory allocation X to be at least N bytes. 2402 ** ^If the X parameter to sqlite3_realloc(X,N) 2403 ** is a NULL pointer then its behavior is identical to calling 2404 ** sqlite3_malloc(N). 2405 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2406 ** negative then the behavior is exactly the same as calling 2407 ** sqlite3_free(X). 2408 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2409 ** of at least N bytes in size or NULL if insufficient memory is available. 2410 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2411 ** of the prior allocation are copied into the beginning of buffer returned 2412 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2413 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2414 ** prior allocation is not freed. 2415 ** 2416 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2417 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2418 ** of a 32-bit signed integer. 2419 ** 2420 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2421 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2422 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2423 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2424 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2425 ** sqlite3_msize(X) returns zero. If X points to something that is not 2426 ** the beginning of memory allocation, or if it points to a formerly 2427 ** valid memory allocation that has now been freed, then the behavior 2428 ** of sqlite3_msize(X) is undefined and possibly harmful. 2429 ** 2430 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2431 ** sqlite3_malloc64(), and sqlite3_realloc64() 2432 ** is always aligned to at least an 8 byte boundary, or to a 2433 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2434 ** option is used. 2435 ** 2436 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2437 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2438 ** implementation of these routines to be omitted. That capability 2439 ** is no longer provided. Only built-in memory allocators can be used. 2440 ** 2441 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2442 ** the system malloc() and free() directly when converting 2443 ** filenames between the UTF-8 encoding used by SQLite 2444 ** and whatever filename encoding is used by the particular Windows 2445 ** installation. Memory allocation errors were detected, but 2446 ** they were reported back as [SQLITE_CANTOPEN] or 2447 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2448 ** 2449 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2450 ** must be either NULL or else pointers obtained from a prior 2451 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2452 ** not yet been released. 2453 ** 2454 ** The application must not read or write any part of 2455 ** a block of memory after it has been released using 2456 ** [sqlite3_free()] or [sqlite3_realloc()]. 2457 */ 2458 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int); 2459 SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64); 2460 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int); 2461 SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64); 2462 SQLITE_API void SQLITE_STDCALL sqlite3_free(void*); 2463 SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*); 2464 2465 /* 2466 ** CAPI3REF: Memory Allocator Statistics 2467 ** 2468 ** SQLite provides these two interfaces for reporting on the status 2469 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2470 ** routines, which form the built-in memory allocation subsystem. 2471 ** 2472 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2473 ** of memory currently outstanding (malloced but not freed). 2474 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2475 ** value of [sqlite3_memory_used()] since the high-water mark 2476 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2477 ** [sqlite3_memory_highwater()] include any overhead 2478 ** added by SQLite in its implementation of [sqlite3_malloc()], 2479 ** but not overhead added by the any underlying system library 2480 ** routines that [sqlite3_malloc()] may call. 2481 ** 2482 ** ^The memory high-water mark is reset to the current value of 2483 ** [sqlite3_memory_used()] if and only if the parameter to 2484 ** [sqlite3_memory_highwater()] is true. ^The value returned 2485 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2486 ** prior to the reset. 2487 */ 2488 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void); 2489 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag); 2490 2491 /* 2492 ** CAPI3REF: Pseudo-Random Number Generator 2493 ** 2494 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2495 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2496 ** already uses the largest possible [ROWID]. The PRNG is also used for 2497 ** the build-in random() and randomblob() SQL functions. This interface allows 2498 ** applications to access the same PRNG for other purposes. 2499 ** 2500 ** ^A call to this routine stores N bytes of randomness into buffer P. 2501 ** ^The P parameter can be a NULL pointer. 2502 ** 2503 ** ^If this routine has not been previously called or if the previous 2504 ** call had N less than one or a NULL pointer for P, then the PRNG is 2505 ** seeded using randomness obtained from the xRandomness method of 2506 ** the default [sqlite3_vfs] object. 2507 ** ^If the previous call to this routine had an N of 1 or more and a 2508 ** non-NULL P then the pseudo-randomness is generated 2509 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2510 ** method. 2511 */ 2512 SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P); 2513 2514 /* 2515 ** CAPI3REF: Compile-Time Authorization Callbacks 2516 ** METHOD: sqlite3 2517 ** 2518 ** ^This routine registers an authorizer callback with a particular 2519 ** [database connection], supplied in the first argument. 2520 ** ^The authorizer callback is invoked as SQL statements are being compiled 2521 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2522 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2523 ** points during the compilation process, as logic is being created 2524 ** to perform various actions, the authorizer callback is invoked to 2525 ** see if those actions are allowed. ^The authorizer callback should 2526 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2527 ** specific action but allow the SQL statement to continue to be 2528 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2529 ** rejected with an error. ^If the authorizer callback returns 2530 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2531 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2532 ** the authorizer will fail with an error message. 2533 ** 2534 ** When the callback returns [SQLITE_OK], that means the operation 2535 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2536 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2537 ** authorizer will fail with an error message explaining that 2538 ** access is denied. 2539 ** 2540 ** ^The first parameter to the authorizer callback is a copy of the third 2541 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2542 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2543 ** the particular action to be authorized. ^The third through sixth parameters 2544 ** to the callback are zero-terminated strings that contain additional 2545 ** details about the action to be authorized. 2546 ** 2547 ** ^If the action code is [SQLITE_READ] 2548 ** and the callback returns [SQLITE_IGNORE] then the 2549 ** [prepared statement] statement is constructed to substitute 2550 ** a NULL value in place of the table column that would have 2551 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2552 ** return can be used to deny an untrusted user access to individual 2553 ** columns of a table. 2554 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2555 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2556 ** [truncate optimization] is disabled and all rows are deleted individually. 2557 ** 2558 ** An authorizer is used when [sqlite3_prepare | preparing] 2559 ** SQL statements from an untrusted source, to ensure that the SQL statements 2560 ** do not try to access data they are not allowed to see, or that they do not 2561 ** try to execute malicious statements that damage the database. For 2562 ** example, an application may allow a user to enter arbitrary 2563 ** SQL queries for evaluation by a database. But the application does 2564 ** not want the user to be able to make arbitrary changes to the 2565 ** database. An authorizer could then be put in place while the 2566 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2567 ** disallows everything except [SELECT] statements. 2568 ** 2569 ** Applications that need to process SQL from untrusted sources 2570 ** might also consider lowering resource limits using [sqlite3_limit()] 2571 ** and limiting database size using the [max_page_count] [PRAGMA] 2572 ** in addition to using an authorizer. 2573 ** 2574 ** ^(Only a single authorizer can be in place on a database connection 2575 ** at a time. Each call to sqlite3_set_authorizer overrides the 2576 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2577 ** The authorizer is disabled by default. 2578 ** 2579 ** The authorizer callback must not do anything that will modify 2580 ** the database connection that invoked the authorizer callback. 2581 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2582 ** database connections for the meaning of "modify" in this paragraph. 2583 ** 2584 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2585 ** statement might be re-prepared during [sqlite3_step()] due to a 2586 ** schema change. Hence, the application should ensure that the 2587 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2588 ** 2589 ** ^Note that the authorizer callback is invoked only during 2590 ** [sqlite3_prepare()] or its variants. Authorization is not 2591 ** performed during statement evaluation in [sqlite3_step()], unless 2592 ** as stated in the previous paragraph, sqlite3_step() invokes 2593 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2594 */ 2595 SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer( 2596 sqlite3*, 2597 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2598 void *pUserData 2599 ); 2600 2601 /* 2602 ** CAPI3REF: Authorizer Return Codes 2603 ** 2604 ** The [sqlite3_set_authorizer | authorizer callback function] must 2605 ** return either [SQLITE_OK] or one of these two constants in order 2606 ** to signal SQLite whether or not the action is permitted. See the 2607 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2608 ** information. 2609 ** 2610 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2611 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2612 */ 2613 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2614 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2615 2616 /* 2617 ** CAPI3REF: Authorizer Action Codes 2618 ** 2619 ** The [sqlite3_set_authorizer()] interface registers a callback function 2620 ** that is invoked to authorize certain SQL statement actions. The 2621 ** second parameter to the callback is an integer code that specifies 2622 ** what action is being authorized. These are the integer action codes that 2623 ** the authorizer callback may be passed. 2624 ** 2625 ** These action code values signify what kind of operation is to be 2626 ** authorized. The 3rd and 4th parameters to the authorization 2627 ** callback function will be parameters or NULL depending on which of these 2628 ** codes is used as the second parameter. ^(The 5th parameter to the 2629 ** authorizer callback is the name of the database ("main", "temp", 2630 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2631 ** is the name of the inner-most trigger or view that is responsible for 2632 ** the access attempt or NULL if this access attempt is directly from 2633 ** top-level SQL code. 2634 */ 2635 /******************************************* 3rd ************ 4th ***********/ 2636 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2637 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2638 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2639 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2640 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2641 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2642 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2643 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2644 #define SQLITE_DELETE 9 /* Table Name NULL */ 2645 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2646 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2647 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2648 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2649 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2650 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2651 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2652 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2653 #define SQLITE_INSERT 18 /* Table Name NULL */ 2654 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2655 #define SQLITE_READ 20 /* Table Name Column Name */ 2656 #define SQLITE_SELECT 21 /* NULL NULL */ 2657 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2658 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2659 #define SQLITE_ATTACH 24 /* Filename NULL */ 2660 #define SQLITE_DETACH 25 /* Database Name NULL */ 2661 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2662 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2663 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2664 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2665 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2666 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2667 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2668 #define SQLITE_COPY 0 /* No longer used */ 2669 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2670 2671 /* 2672 ** CAPI3REF: Tracing And Profiling Functions 2673 ** METHOD: sqlite3 2674 ** 2675 ** These routines register callback functions that can be used for 2676 ** tracing and profiling the execution of SQL statements. 2677 ** 2678 ** ^The callback function registered by sqlite3_trace() is invoked at 2679 ** various times when an SQL statement is being run by [sqlite3_step()]. 2680 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2681 ** SQL statement text as the statement first begins executing. 2682 ** ^(Additional sqlite3_trace() callbacks might occur 2683 ** as each triggered subprogram is entered. The callbacks for triggers 2684 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2685 ** 2686 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2687 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2688 ** 2689 ** ^The callback function registered by sqlite3_profile() is invoked 2690 ** as each SQL statement finishes. ^The profile callback contains 2691 ** the original statement text and an estimate of wall-clock time 2692 ** of how long that statement took to run. ^The profile callback 2693 ** time is in units of nanoseconds, however the current implementation 2694 ** is only capable of millisecond resolution so the six least significant 2695 ** digits in the time are meaningless. Future versions of SQLite 2696 ** might provide greater resolution on the profiler callback. The 2697 ** sqlite3_profile() function is considered experimental and is 2698 ** subject to change in future versions of SQLite. 2699 */ 2700 SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2701 SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*, 2702 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2703 2704 /* 2705 ** CAPI3REF: Query Progress Callbacks 2706 ** METHOD: sqlite3 2707 ** 2708 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2709 ** function X to be invoked periodically during long running calls to 2710 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2711 ** database connection D. An example use for this 2712 ** interface is to keep a GUI updated during a large query. 2713 ** 2714 ** ^The parameter P is passed through as the only parameter to the 2715 ** callback function X. ^The parameter N is the approximate number of 2716 ** [virtual machine instructions] that are evaluated between successive 2717 ** invocations of the callback X. ^If N is less than one then the progress 2718 ** handler is disabled. 2719 ** 2720 ** ^Only a single progress handler may be defined at one time per 2721 ** [database connection]; setting a new progress handler cancels the 2722 ** old one. ^Setting parameter X to NULL disables the progress handler. 2723 ** ^The progress handler is also disabled by setting N to a value less 2724 ** than 1. 2725 ** 2726 ** ^If the progress callback returns non-zero, the operation is 2727 ** interrupted. This feature can be used to implement a 2728 ** "Cancel" button on a GUI progress dialog box. 2729 ** 2730 ** The progress handler callback must not do anything that will modify 2731 ** the database connection that invoked the progress handler. 2732 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2733 ** database connections for the meaning of "modify" in this paragraph. 2734 ** 2735 */ 2736 SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2737 2738 /* 2739 ** CAPI3REF: Opening A New Database Connection 2740 ** CONSTRUCTOR: sqlite3 2741 ** 2742 ** ^These routines open an SQLite database file as specified by the 2743 ** filename argument. ^The filename argument is interpreted as UTF-8 for 2744 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2745 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2746 ** returned in *ppDb, even if an error occurs. The only exception is that 2747 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2748 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2749 ** object.)^ ^(If the database is opened (and/or created) successfully, then 2750 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2751 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2752 ** an English language description of the error following a failure of any 2753 ** of the sqlite3_open() routines. 2754 ** 2755 ** ^The default encoding will be UTF-8 for databases created using 2756 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2757 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 2758 ** 2759 ** Whether or not an error occurs when it is opened, resources 2760 ** associated with the [database connection] handle should be released by 2761 ** passing it to [sqlite3_close()] when it is no longer required. 2762 ** 2763 ** The sqlite3_open_v2() interface works like sqlite3_open() 2764 ** except that it accepts two additional parameters for additional control 2765 ** over the new database connection. ^(The flags parameter to 2766 ** sqlite3_open_v2() can take one of 2767 ** the following three values, optionally combined with the 2768 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2769 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2770 ** 2771 ** <dl> 2772 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2773 ** <dd>The database is opened in read-only mode. If the database does not 2774 ** already exist, an error is returned.</dd>)^ 2775 ** 2776 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2777 ** <dd>The database is opened for reading and writing if possible, or reading 2778 ** only if the file is write protected by the operating system. In either 2779 ** case the database must already exist, otherwise an error is returned.</dd>)^ 2780 ** 2781 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2782 ** <dd>The database is opened for reading and writing, and is created if 2783 ** it does not already exist. This is the behavior that is always used for 2784 ** sqlite3_open() and sqlite3_open16().</dd>)^ 2785 ** </dl> 2786 ** 2787 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 2788 ** combinations shown above optionally combined with other 2789 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2790 ** then the behavior is undefined. 2791 ** 2792 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2793 ** opens in the multi-thread [threading mode] as long as the single-thread 2794 ** mode has not been set at compile-time or start-time. ^If the 2795 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2796 ** in the serialized [threading mode] unless single-thread was 2797 ** previously selected at compile-time or start-time. 2798 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2799 ** eligible to use [shared cache mode], regardless of whether or not shared 2800 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2801 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2802 ** participate in [shared cache mode] even if it is enabled. 2803 ** 2804 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 2805 ** [sqlite3_vfs] object that defines the operating system interface that 2806 ** the new database connection should use. ^If the fourth parameter is 2807 ** a NULL pointer then the default [sqlite3_vfs] object is used. 2808 ** 2809 ** ^If the filename is ":memory:", then a private, temporary in-memory database 2810 ** is created for the connection. ^This in-memory database will vanish when 2811 ** the database connection is closed. Future versions of SQLite might 2812 ** make use of additional special filenames that begin with the ":" character. 2813 ** It is recommended that when a database filename actually does begin with 2814 ** a ":" character you should prefix the filename with a pathname such as 2815 ** "./" to avoid ambiguity. 2816 ** 2817 ** ^If the filename is an empty string, then a private, temporary 2818 ** on-disk database will be created. ^This private database will be 2819 ** automatically deleted as soon as the database connection is closed. 2820 ** 2821 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2822 ** 2823 ** ^If [URI filename] interpretation is enabled, and the filename argument 2824 ** begins with "file:", then the filename is interpreted as a URI. ^URI 2825 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2826 ** set in the fourth argument to sqlite3_open_v2(), or if it has 2827 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2828 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2829 ** As of SQLite version 3.7.7, URI filename interpretation is turned off 2830 ** by default, but future releases of SQLite might enable URI filename 2831 ** interpretation by default. See "[URI filenames]" for additional 2832 ** information. 2833 ** 2834 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2835 ** authority, then it must be either an empty string or the string 2836 ** "localhost". ^If the authority is not an empty string or "localhost", an 2837 ** error is returned to the caller. ^The fragment component of a URI, if 2838 ** present, is ignored. 2839 ** 2840 ** ^SQLite uses the path component of the URI as the name of the disk file 2841 ** which contains the database. ^If the path begins with a '/' character, 2842 ** then it is interpreted as an absolute path. ^If the path does not begin 2843 ** with a '/' (meaning that the authority section is omitted from the URI) 2844 ** then the path is interpreted as a relative path. 2845 ** ^(On windows, the first component of an absolute path 2846 ** is a drive specification (e.g. "C:").)^ 2847 ** 2848 ** [[core URI query parameters]] 2849 ** The query component of a URI may contain parameters that are interpreted 2850 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2851 ** SQLite and its built-in [VFSes] interpret the 2852 ** following query parameters: 2853 ** 2854 ** <ul> 2855 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2856 ** a VFS object that provides the operating system interface that should 2857 ** be used to access the database file on disk. ^If this option is set to 2858 ** an empty string the default VFS object is used. ^Specifying an unknown 2859 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2860 ** present, then the VFS specified by the option takes precedence over 2861 ** the value passed as the fourth parameter to sqlite3_open_v2(). 2862 ** 2863 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2864 ** "rwc", or "memory". Attempting to set it to any other value is 2865 ** an error)^. 2866 ** ^If "ro" is specified, then the database is opened for read-only 2867 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2868 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 2869 ** "rw", then the database is opened for read-write (but not create) 2870 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2871 ** been set. ^Value "rwc" is equivalent to setting both 2872 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2873 ** set to "memory" then a pure [in-memory database] that never reads 2874 ** or writes from disk is used. ^It is an error to specify a value for 2875 ** the mode parameter that is less restrictive than that specified by 2876 ** the flags passed in the third parameter to sqlite3_open_v2(). 2877 ** 2878 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2879 ** "private". ^Setting it to "shared" is equivalent to setting the 2880 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2881 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2882 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2883 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2884 ** a URI filename, its value overrides any behavior requested by setting 2885 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2886 ** 2887 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 2888 ** [powersafe overwrite] property does or does not apply to the 2889 ** storage media on which the database file resides. 2890 ** 2891 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2892 ** which if set disables file locking in rollback journal modes. This 2893 ** is useful for accessing a database on a filesystem that does not 2894 ** support locking. Caution: Database corruption might result if two 2895 ** or more processes write to the same database and any one of those 2896 ** processes uses nolock=1. 2897 ** 2898 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2899 ** parameter that indicates that the database file is stored on 2900 ** read-only media. ^When immutable is set, SQLite assumes that the 2901 ** database file cannot be changed, even by a process with higher 2902 ** privilege, and so the database is opened read-only and all locking 2903 ** and change detection is disabled. Caution: Setting the immutable 2904 ** property on a database file that does in fact change can result 2905 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2906 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 2907 ** 2908 ** </ul> 2909 ** 2910 ** ^Specifying an unknown parameter in the query component of a URI is not an 2911 ** error. Future versions of SQLite might understand additional query 2912 ** parameters. See "[query parameters with special meaning to SQLite]" for 2913 ** additional information. 2914 ** 2915 ** [[URI filename examples]] <h3>URI filename examples</h3> 2916 ** 2917 ** <table border="1" align=center cellpadding=5> 2918 ** <tr><th> URI filenames <th> Results 2919 ** <tr><td> file:data.db <td> 2920 ** Open the file "data.db" in the current directory. 2921 ** <tr><td> file:/home/fred/data.db<br> 2922 ** file:///home/fred/data.db <br> 2923 ** file://localhost/home/fred/data.db <br> <td> 2924 ** Open the database file "/home/fred/data.db". 2925 ** <tr><td> file://darkstar/home/fred/data.db <td> 2926 ** An error. "darkstar" is not a recognized authority. 2927 ** <tr><td style="white-space:nowrap"> 2928 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2929 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2930 ** C:. Note that the %20 escaping in this example is not strictly 2931 ** necessary - space characters can be used literally 2932 ** in URI filenames. 2933 ** <tr><td> file:data.db?mode=ro&cache=private <td> 2934 ** Open file "data.db" in the current directory for read-only access. 2935 ** Regardless of whether or not shared-cache mode is enabled by 2936 ** default, use a private cache. 2937 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 2938 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 2939 ** that uses dot-files in place of posix advisory locking. 2940 ** <tr><td> file:data.db?mode=readonly <td> 2941 ** An error. "readonly" is not a valid option for the "mode" parameter. 2942 ** </table> 2943 ** 2944 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2945 ** query components of a URI. A hexadecimal escape sequence consists of a 2946 ** percent sign - "%" - followed by exactly two hexadecimal digits 2947 ** specifying an octet value. ^Before the path or query components of a 2948 ** URI filename are interpreted, they are encoded using UTF-8 and all 2949 ** hexadecimal escape sequences replaced by a single byte containing the 2950 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 2951 ** the results are undefined. 2952 ** 2953 ** <b>Note to Windows users:</b> The encoding used for the filename argument 2954 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2955 ** codepage is currently defined. Filenames containing international 2956 ** characters must be converted to UTF-8 prior to passing them into 2957 ** sqlite3_open() or sqlite3_open_v2(). 2958 ** 2959 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2960 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2961 ** features that require the use of temporary files may fail. 2962 ** 2963 ** See also: [sqlite3_temp_directory] 2964 */ 2965 SQLITE_API int SQLITE_STDCALL sqlite3_open( 2966 const char *filename, /* Database filename (UTF-8) */ 2967 sqlite3 **ppDb /* OUT: SQLite db handle */ 2968 ); 2969 SQLITE_API int SQLITE_STDCALL sqlite3_open16( 2970 const void *filename, /* Database filename (UTF-16) */ 2971 sqlite3 **ppDb /* OUT: SQLite db handle */ 2972 ); 2973 SQLITE_API int SQLITE_STDCALL sqlite3_open_v2( 2974 const char *filename, /* Database filename (UTF-8) */ 2975 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2976 int flags, /* Flags */ 2977 const char *zVfs /* Name of VFS module to use */ 2978 ); 2979 2980 /* 2981 ** CAPI3REF: Obtain Values For URI Parameters 2982 ** 2983 ** These are utility routines, useful to VFS implementations, that check 2984 ** to see if a database file was a URI that contained a specific query 2985 ** parameter, and if so obtains the value of that query parameter. 2986 ** 2987 ** If F is the database filename pointer passed into the xOpen() method of 2988 ** a VFS implementation when the flags parameter to xOpen() has one or 2989 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2990 ** P is the name of the query parameter, then 2991 ** sqlite3_uri_parameter(F,P) returns the value of the P 2992 ** parameter if it exists or a NULL pointer if P does not appear as a 2993 ** query parameter on F. If P is a query parameter of F 2994 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2995 ** a pointer to an empty string. 2996 ** 2997 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2998 ** parameter and returns true (1) or false (0) according to the value 2999 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3000 ** value of query parameter P is one of "yes", "true", or "on" in any 3001 ** case or if the value begins with a non-zero number. The 3002 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3003 ** query parameter P is one of "no", "false", or "off" in any case or 3004 ** if the value begins with a numeric zero. If P is not a query 3005 ** parameter on F or if the value of P is does not match any of the 3006 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3007 ** 3008 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3009 ** 64-bit signed integer and returns that integer, or D if P does not 3010 ** exist. If the value of P is something other than an integer, then 3011 ** zero is returned. 3012 ** 3013 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3014 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3015 ** is not a database file pathname pointer that SQLite passed into the xOpen 3016 ** VFS method, then the behavior of this routine is undefined and probably 3017 ** undesirable. 3018 */ 3019 SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3020 SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3021 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3022 3023 3024 /* 3025 ** CAPI3REF: Error Codes And Messages 3026 ** METHOD: sqlite3 3027 ** 3028 ** ^If the most recent sqlite3_* API call associated with 3029 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3030 ** returns the numeric [result code] or [extended result code] for that 3031 ** API call. 3032 ** If the most recent API call was successful, 3033 ** then the return value from sqlite3_errcode() is undefined. 3034 ** ^The sqlite3_extended_errcode() 3035 ** interface is the same except that it always returns the 3036 ** [extended result code] even when extended result codes are 3037 ** disabled. 3038 ** 3039 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3040 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3041 ** ^(Memory to hold the error message string is managed internally. 3042 ** The application does not need to worry about freeing the result. 3043 ** However, the error string might be overwritten or deallocated by 3044 ** subsequent calls to other SQLite interface functions.)^ 3045 ** 3046 ** ^The sqlite3_errstr() interface returns the English-language text 3047 ** that describes the [result code], as UTF-8. 3048 ** ^(Memory to hold the error message string is managed internally 3049 ** and must not be freed by the application)^. 3050 ** 3051 ** When the serialized [threading mode] is in use, it might be the 3052 ** case that a second error occurs on a separate thread in between 3053 ** the time of the first error and the call to these interfaces. 3054 ** When that happens, the second error will be reported since these 3055 ** interfaces always report the most recent result. To avoid 3056 ** this, each thread can obtain exclusive use of the [database connection] D 3057 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3058 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3059 ** all calls to the interfaces listed here are completed. 3060 ** 3061 ** If an interface fails with SQLITE_MISUSE, that means the interface 3062 ** was invoked incorrectly by the application. In that case, the 3063 ** error code and message may or may not be set. 3064 */ 3065 SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db); 3066 SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db); 3067 SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*); 3068 SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*); 3069 SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int); 3070 3071 /* 3072 ** CAPI3REF: Prepared Statement Object 3073 ** KEYWORDS: {prepared statement} {prepared statements} 3074 ** 3075 ** An instance of this object represents a single SQL statement that 3076 ** has been compiled into binary form and is ready to be evaluated. 3077 ** 3078 ** Think of each SQL statement as a separate computer program. The 3079 ** original SQL text is source code. A prepared statement object 3080 ** is the compiled object code. All SQL must be converted into a 3081 ** prepared statement before it can be run. 3082 ** 3083 ** The life-cycle of a prepared statement object usually goes like this: 3084 ** 3085 ** <ol> 3086 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3087 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3088 ** interfaces. 3089 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3090 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3091 ** to step 2. Do this zero or more times. 3092 ** <li> Destroy the object using [sqlite3_finalize()]. 3093 ** </ol> 3094 */ 3095 typedef struct sqlite3_stmt sqlite3_stmt; 3096 3097 /* 3098 ** CAPI3REF: Run-time Limits 3099 ** METHOD: sqlite3 3100 ** 3101 ** ^(This interface allows the size of various constructs to be limited 3102 ** on a connection by connection basis. The first parameter is the 3103 ** [database connection] whose limit is to be set or queried. The 3104 ** second parameter is one of the [limit categories] that define a 3105 ** class of constructs to be size limited. The third parameter is the 3106 ** new limit for that construct.)^ 3107 ** 3108 ** ^If the new limit is a negative number, the limit is unchanged. 3109 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3110 ** [limits | hard upper bound] 3111 ** set at compile-time by a C preprocessor macro called 3112 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3113 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3114 ** ^Attempts to increase a limit above its hard upper bound are 3115 ** silently truncated to the hard upper bound. 3116 ** 3117 ** ^Regardless of whether or not the limit was changed, the 3118 ** [sqlite3_limit()] interface returns the prior value of the limit. 3119 ** ^Hence, to find the current value of a limit without changing it, 3120 ** simply invoke this interface with the third parameter set to -1. 3121 ** 3122 ** Run-time limits are intended for use in applications that manage 3123 ** both their own internal database and also databases that are controlled 3124 ** by untrusted external sources. An example application might be a 3125 ** web browser that has its own databases for storing history and 3126 ** separate databases controlled by JavaScript applications downloaded 3127 ** off the Internet. The internal databases can be given the 3128 ** large, default limits. Databases managed by external sources can 3129 ** be given much smaller limits designed to prevent a denial of service 3130 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3131 ** interface to further control untrusted SQL. The size of the database 3132 ** created by an untrusted script can be contained using the 3133 ** [max_page_count] [PRAGMA]. 3134 ** 3135 ** New run-time limit categories may be added in future releases. 3136 */ 3137 SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal); 3138 3139 /* 3140 ** CAPI3REF: Run-Time Limit Categories 3141 ** KEYWORDS: {limit category} {*limit categories} 3142 ** 3143 ** These constants define various performance limits 3144 ** that can be lowered at run-time using [sqlite3_limit()]. 3145 ** The synopsis of the meanings of the various limits is shown below. 3146 ** Additional information is available at [limits | Limits in SQLite]. 3147 ** 3148 ** <dl> 3149 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3150 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3151 ** 3152 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3153 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3154 ** 3155 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3156 ** <dd>The maximum number of columns in a table definition or in the 3157 ** result set of a [SELECT] or the maximum number of columns in an index 3158 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3159 ** 3160 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3161 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3162 ** 3163 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3164 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3165 ** 3166 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3167 ** <dd>The maximum number of instructions in a virtual machine program 3168 ** used to implement an SQL statement. This limit is not currently 3169 ** enforced, though that might be added in some future release of 3170 ** SQLite.</dd>)^ 3171 ** 3172 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3173 ** <dd>The maximum number of arguments on a function.</dd>)^ 3174 ** 3175 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3176 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3177 ** 3178 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3179 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3180 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3181 ** [GLOB] operators.</dd>)^ 3182 ** 3183 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3184 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3185 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3186 ** 3187 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3188 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3189 ** 3190 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3191 ** <dd>The maximum number of auxiliary worker threads that a single 3192 ** [prepared statement] may start.</dd>)^ 3193 ** </dl> 3194 */ 3195 #define SQLITE_LIMIT_LENGTH 0 3196 #define SQLITE_LIMIT_SQL_LENGTH 1 3197 #define SQLITE_LIMIT_COLUMN 2 3198 #define SQLITE_LIMIT_EXPR_DEPTH 3 3199 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3200 #define SQLITE_LIMIT_VDBE_OP 5 3201 #define SQLITE_LIMIT_FUNCTION_ARG 6 3202 #define SQLITE_LIMIT_ATTACHED 7 3203 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3204 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3205 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3206 #define SQLITE_LIMIT_WORKER_THREADS 11 3207 3208 /* 3209 ** CAPI3REF: Compiling An SQL Statement 3210 ** KEYWORDS: {SQL statement compiler} 3211 ** METHOD: sqlite3 3212 ** CONSTRUCTOR: sqlite3_stmt 3213 ** 3214 ** To execute an SQL query, it must first be compiled into a byte-code 3215 ** program using one of these routines. 3216 ** 3217 ** The first argument, "db", is a [database connection] obtained from a 3218 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3219 ** [sqlite3_open16()]. The database connection must not have been closed. 3220 ** 3221 ** The second argument, "zSql", is the statement to be compiled, encoded 3222 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3223 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3224 ** use UTF-16. 3225 ** 3226 ** ^If the nByte argument is negative, then zSql is read up to the 3227 ** first zero terminator. ^If nByte is positive, then it is the 3228 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3229 ** statement is generated. 3230 ** If the caller knows that the supplied string is nul-terminated, then 3231 ** there is a small performance advantage to passing an nByte parameter that 3232 ** is the number of bytes in the input string <i>including</i> 3233 ** the nul-terminator. 3234 ** 3235 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3236 ** past the end of the first SQL statement in zSql. These routines only 3237 ** compile the first statement in zSql, so *pzTail is left pointing to 3238 ** what remains uncompiled. 3239 ** 3240 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3241 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3242 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3243 ** string or a comment) then *ppStmt is set to NULL. 3244 ** The calling procedure is responsible for deleting the compiled 3245 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3246 ** ppStmt may not be NULL. 3247 ** 3248 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3249 ** otherwise an [error code] is returned. 3250 ** 3251 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3252 ** recommended for all new programs. The two older interfaces are retained 3253 ** for backwards compatibility, but their use is discouraged. 3254 ** ^In the "v2" interfaces, the prepared statement 3255 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3256 ** original SQL text. This causes the [sqlite3_step()] interface to 3257 ** behave differently in three ways: 3258 ** 3259 ** <ol> 3260 ** <li> 3261 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3262 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3263 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3264 ** retries will occur before sqlite3_step() gives up and returns an error. 3265 ** </li> 3266 ** 3267 ** <li> 3268 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3269 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3270 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3271 ** and the application would have to make a second call to [sqlite3_reset()] 3272 ** in order to find the underlying cause of the problem. With the "v2" prepare 3273 ** interfaces, the underlying reason for the error is returned immediately. 3274 ** </li> 3275 ** 3276 ** <li> 3277 ** ^If the specific value bound to [parameter | host parameter] in the 3278 ** WHERE clause might influence the choice of query plan for a statement, 3279 ** then the statement will be automatically recompiled, as if there had been 3280 ** a schema change, on the first [sqlite3_step()] call following any change 3281 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3282 ** ^The specific value of WHERE-clause [parameter] might influence the 3283 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3284 ** or [GLOB] operator or if the parameter is compared to an indexed column 3285 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3286 ** </li> 3287 ** </ol> 3288 */ 3289 SQLITE_API int SQLITE_STDCALL sqlite3_prepare( 3290 sqlite3 *db, /* Database handle */ 3291 const char *zSql, /* SQL statement, UTF-8 encoded */ 3292 int nByte, /* Maximum length of zSql in bytes. */ 3293 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3294 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3295 ); 3296 SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2( 3297 sqlite3 *db, /* Database handle */ 3298 const char *zSql, /* SQL statement, UTF-8 encoded */ 3299 int nByte, /* Maximum length of zSql in bytes. */ 3300 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3301 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3302 ); 3303 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16( 3304 sqlite3 *db, /* Database handle */ 3305 const void *zSql, /* SQL statement, UTF-16 encoded */ 3306 int nByte, /* Maximum length of zSql in bytes. */ 3307 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3308 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3309 ); 3310 SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2( 3311 sqlite3 *db, /* Database handle */ 3312 const void *zSql, /* SQL statement, UTF-16 encoded */ 3313 int nByte, /* Maximum length of zSql in bytes. */ 3314 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3315 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3316 ); 3317 3318 /* 3319 ** CAPI3REF: Retrieving Statement SQL 3320 ** METHOD: sqlite3_stmt 3321 ** 3322 ** ^This interface can be used to retrieve a saved copy of the original 3323 ** SQL text used to create a [prepared statement] if that statement was 3324 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3325 */ 3326 SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt); 3327 3328 /* 3329 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3330 ** METHOD: sqlite3_stmt 3331 ** 3332 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3333 ** and only if the [prepared statement] X makes no direct changes to 3334 ** the content of the database file. 3335 ** 3336 ** Note that [application-defined SQL functions] or 3337 ** [virtual tables] might change the database indirectly as a side effect. 3338 ** ^(For example, if an application defines a function "eval()" that 3339 ** calls [sqlite3_exec()], then the following SQL statement would 3340 ** change the database file through side-effects: 3341 ** 3342 ** <blockquote><pre> 3343 ** SELECT eval('DELETE FROM t1') FROM t2; 3344 ** </pre></blockquote> 3345 ** 3346 ** But because the [SELECT] statement does not change the database file 3347 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3348 ** 3349 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3350 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3351 ** since the statements themselves do not actually modify the database but 3352 ** rather they control the timing of when other statements modify the 3353 ** database. ^The [ATTACH] and [DETACH] statements also cause 3354 ** sqlite3_stmt_readonly() to return true since, while those statements 3355 ** change the configuration of a database connection, they do not make 3356 ** changes to the content of the database files on disk. 3357 */ 3358 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3359 3360 /* 3361 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3362 ** METHOD: sqlite3_stmt 3363 ** 3364 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3365 ** [prepared statement] S has been stepped at least once using 3366 ** [sqlite3_step(S)] but has not run to completion and/or has not 3367 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3368 ** interface returns false if S is a NULL pointer. If S is not a 3369 ** NULL pointer and is not a pointer to a valid [prepared statement] 3370 ** object, then the behavior is undefined and probably undesirable. 3371 ** 3372 ** This interface can be used in combination [sqlite3_next_stmt()] 3373 ** to locate all prepared statements associated with a database 3374 ** connection that are in need of being reset. This can be used, 3375 ** for example, in diagnostic routines to search for prepared 3376 ** statements that are holding a transaction open. 3377 */ 3378 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*); 3379 3380 /* 3381 ** CAPI3REF: Dynamically Typed Value Object 3382 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3383 ** 3384 ** SQLite uses the sqlite3_value object to represent all values 3385 ** that can be stored in a database table. SQLite uses dynamic typing 3386 ** for the values it stores. ^Values stored in sqlite3_value objects 3387 ** can be integers, floating point values, strings, BLOBs, or NULL. 3388 ** 3389 ** An sqlite3_value object may be either "protected" or "unprotected". 3390 ** Some interfaces require a protected sqlite3_value. Other interfaces 3391 ** will accept either a protected or an unprotected sqlite3_value. 3392 ** Every interface that accepts sqlite3_value arguments specifies 3393 ** whether or not it requires a protected sqlite3_value. 3394 ** 3395 ** The terms "protected" and "unprotected" refer to whether or not 3396 ** a mutex is held. An internal mutex is held for a protected 3397 ** sqlite3_value object but no mutex is held for an unprotected 3398 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3399 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3400 ** or if SQLite is run in one of reduced mutex modes 3401 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3402 ** then there is no distinction between protected and unprotected 3403 ** sqlite3_value objects and they can be used interchangeably. However, 3404 ** for maximum code portability it is recommended that applications 3405 ** still make the distinction between protected and unprotected 3406 ** sqlite3_value objects even when not strictly required. 3407 ** 3408 ** ^The sqlite3_value objects that are passed as parameters into the 3409 ** implementation of [application-defined SQL functions] are protected. 3410 ** ^The sqlite3_value object returned by 3411 ** [sqlite3_column_value()] is unprotected. 3412 ** Unprotected sqlite3_value objects may only be used with 3413 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3414 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3415 ** interfaces require protected sqlite3_value objects. 3416 */ 3417 typedef struct Mem sqlite3_value; 3418 3419 /* 3420 ** CAPI3REF: SQL Function Context Object 3421 ** 3422 ** The context in which an SQL function executes is stored in an 3423 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3424 ** is always first parameter to [application-defined SQL functions]. 3425 ** The application-defined SQL function implementation will pass this 3426 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3427 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3428 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3429 ** and/or [sqlite3_set_auxdata()]. 3430 */ 3431 typedef struct sqlite3_context sqlite3_context; 3432 3433 /* 3434 ** CAPI3REF: Binding Values To Prepared Statements 3435 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3436 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3437 ** METHOD: sqlite3_stmt 3438 ** 3439 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3440 ** literals may be replaced by a [parameter] that matches one of following 3441 ** templates: 3442 ** 3443 ** <ul> 3444 ** <li> ? 3445 ** <li> ?NNN 3446 ** <li> :VVV 3447 ** <li> @VVV 3448 ** <li> $VVV 3449 ** </ul> 3450 ** 3451 ** In the templates above, NNN represents an integer literal, 3452 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3453 ** parameters (also called "host parameter names" or "SQL parameters") 3454 ** can be set using the sqlite3_bind_*() routines defined here. 3455 ** 3456 ** ^The first argument to the sqlite3_bind_*() routines is always 3457 ** a pointer to the [sqlite3_stmt] object returned from 3458 ** [sqlite3_prepare_v2()] or its variants. 3459 ** 3460 ** ^The second argument is the index of the SQL parameter to be set. 3461 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3462 ** SQL parameter is used more than once, second and subsequent 3463 ** occurrences have the same index as the first occurrence. 3464 ** ^The index for named parameters can be looked up using the 3465 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3466 ** for "?NNN" parameters is the value of NNN. 3467 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3468 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3469 ** 3470 ** ^The third argument is the value to bind to the parameter. 3471 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3472 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3473 ** is ignored and the end result is the same as sqlite3_bind_null(). 3474 ** 3475 ** ^(In those routines that have a fourth argument, its value is the 3476 ** number of bytes in the parameter. To be clear: the value is the 3477 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3478 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3479 ** is negative, then the length of the string is 3480 ** the number of bytes up to the first zero terminator. 3481 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3482 ** the behavior is undefined. 3483 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3484 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3485 ** that parameter must be the byte offset 3486 ** where the NUL terminator would occur assuming the string were NUL 3487 ** terminated. If any NUL characters occur at byte offsets less than 3488 ** the value of the fourth parameter then the resulting string value will 3489 ** contain embedded NULs. The result of expressions involving strings 3490 ** with embedded NULs is undefined. 3491 ** 3492 ** ^The fifth argument to the BLOB and string binding interfaces 3493 ** is a destructor used to dispose of the BLOB or 3494 ** string after SQLite has finished with it. ^The destructor is called 3495 ** to dispose of the BLOB or string even if the call to bind API fails. 3496 ** ^If the fifth argument is 3497 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3498 ** information is in static, unmanaged space and does not need to be freed. 3499 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3500 ** SQLite makes its own private copy of the data immediately, before 3501 ** the sqlite3_bind_*() routine returns. 3502 ** 3503 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3504 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3505 ** to specify the encoding of the text in the third parameter. If 3506 ** the sixth argument to sqlite3_bind_text64() is not one of the 3507 ** allowed values shown above, or if the text encoding is different 3508 ** from the encoding specified by the sixth parameter, then the behavior 3509 ** is undefined. 3510 ** 3511 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3512 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3513 ** (just an integer to hold its size) while it is being processed. 3514 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3515 ** content is later written using 3516 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3517 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3518 ** 3519 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3520 ** for the [prepared statement] or with a prepared statement for which 3521 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3522 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3523 ** routine is passed a [prepared statement] that has been finalized, the 3524 ** result is undefined and probably harmful. 3525 ** 3526 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3527 ** ^Unbound parameters are interpreted as NULL. 3528 ** 3529 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3530 ** [error code] if anything goes wrong. 3531 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3532 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3533 ** [SQLITE_MAX_LENGTH]. 3534 ** ^[SQLITE_RANGE] is returned if the parameter 3535 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3536 ** 3537 ** See also: [sqlite3_bind_parameter_count()], 3538 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3539 */ 3540 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3541 SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3542 void(*)(void*)); 3543 SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double); 3544 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int); 3545 SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3546 SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int); 3547 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3548 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3549 SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3550 void(*)(void*), unsigned char encoding); 3551 SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3552 SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3553 3554 /* 3555 ** CAPI3REF: Number Of SQL Parameters 3556 ** METHOD: sqlite3_stmt 3557 ** 3558 ** ^This routine can be used to find the number of [SQL parameters] 3559 ** in a [prepared statement]. SQL parameters are tokens of the 3560 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3561 ** placeholders for values that are [sqlite3_bind_blob | bound] 3562 ** to the parameters at a later time. 3563 ** 3564 ** ^(This routine actually returns the index of the largest (rightmost) 3565 ** parameter. For all forms except ?NNN, this will correspond to the 3566 ** number of unique parameters. If parameters of the ?NNN form are used, 3567 ** there may be gaps in the list.)^ 3568 ** 3569 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3570 ** [sqlite3_bind_parameter_name()], and 3571 ** [sqlite3_bind_parameter_index()]. 3572 */ 3573 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*); 3574 3575 /* 3576 ** CAPI3REF: Name Of A Host Parameter 3577 ** METHOD: sqlite3_stmt 3578 ** 3579 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3580 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3581 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3582 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3583 ** respectively. 3584 ** In other words, the initial ":" or "$" or "@" or "?" 3585 ** is included as part of the name.)^ 3586 ** ^Parameters of the form "?" without a following integer have no name 3587 ** and are referred to as "nameless" or "anonymous parameters". 3588 ** 3589 ** ^The first host parameter has an index of 1, not 0. 3590 ** 3591 ** ^If the value N is out of range or if the N-th parameter is 3592 ** nameless, then NULL is returned. ^The returned string is 3593 ** always in UTF-8 encoding even if the named parameter was 3594 ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3595 ** [sqlite3_prepare16_v2()]. 3596 ** 3597 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3598 ** [sqlite3_bind_parameter_count()], and 3599 ** [sqlite3_bind_parameter_index()]. 3600 */ 3601 SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3602 3603 /* 3604 ** CAPI3REF: Index Of A Parameter With A Given Name 3605 ** METHOD: sqlite3_stmt 3606 ** 3607 ** ^Return the index of an SQL parameter given its name. ^The 3608 ** index value returned is suitable for use as the second 3609 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3610 ** is returned if no matching parameter is found. ^The parameter 3611 ** name must be given in UTF-8 even if the original statement 3612 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3613 ** 3614 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3615 ** [sqlite3_bind_parameter_count()], and 3616 ** [sqlite3_bind_parameter_index()]. 3617 */ 3618 SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3619 3620 /* 3621 ** CAPI3REF: Reset All Bindings On A Prepared Statement 3622 ** METHOD: sqlite3_stmt 3623 ** 3624 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3625 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3626 ** ^Use this routine to reset all host parameters to NULL. 3627 */ 3628 SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*); 3629 3630 /* 3631 ** CAPI3REF: Number Of Columns In A Result Set 3632 ** METHOD: sqlite3_stmt 3633 ** 3634 ** ^Return the number of columns in the result set returned by the 3635 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3636 ** statement that does not return data (for example an [UPDATE]). 3637 ** 3638 ** See also: [sqlite3_data_count()] 3639 */ 3640 SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt); 3641 3642 /* 3643 ** CAPI3REF: Column Names In A Result Set 3644 ** METHOD: sqlite3_stmt 3645 ** 3646 ** ^These routines return the name assigned to a particular column 3647 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3648 ** interface returns a pointer to a zero-terminated UTF-8 string 3649 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3650 ** UTF-16 string. ^The first parameter is the [prepared statement] 3651 ** that implements the [SELECT] statement. ^The second parameter is the 3652 ** column number. ^The leftmost column is number 0. 3653 ** 3654 ** ^The returned string pointer is valid until either the [prepared statement] 3655 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3656 ** reprepared by the first call to [sqlite3_step()] for a particular run 3657 ** or until the next call to 3658 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3659 ** 3660 ** ^If sqlite3_malloc() fails during the processing of either routine 3661 ** (for example during a conversion from UTF-8 to UTF-16) then a 3662 ** NULL pointer is returned. 3663 ** 3664 ** ^The name of a result column is the value of the "AS" clause for 3665 ** that column, if there is an AS clause. If there is no AS clause 3666 ** then the name of the column is unspecified and may change from 3667 ** one release of SQLite to the next. 3668 */ 3669 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N); 3670 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N); 3671 3672 /* 3673 ** CAPI3REF: Source Of Data In A Query Result 3674 ** METHOD: sqlite3_stmt 3675 ** 3676 ** ^These routines provide a means to determine the database, table, and 3677 ** table column that is the origin of a particular result column in 3678 ** [SELECT] statement. 3679 ** ^The name of the database or table or column can be returned as 3680 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3681 ** the database name, the _table_ routines return the table name, and 3682 ** the origin_ routines return the column name. 3683 ** ^The returned string is valid until the [prepared statement] is destroyed 3684 ** using [sqlite3_finalize()] or until the statement is automatically 3685 ** reprepared by the first call to [sqlite3_step()] for a particular run 3686 ** or until the same information is requested 3687 ** again in a different encoding. 3688 ** 3689 ** ^The names returned are the original un-aliased names of the 3690 ** database, table, and column. 3691 ** 3692 ** ^The first argument to these interfaces is a [prepared statement]. 3693 ** ^These functions return information about the Nth result column returned by 3694 ** the statement, where N is the second function argument. 3695 ** ^The left-most column is column 0 for these routines. 3696 ** 3697 ** ^If the Nth column returned by the statement is an expression or 3698 ** subquery and is not a column value, then all of these functions return 3699 ** NULL. ^These routine might also return NULL if a memory allocation error 3700 ** occurs. ^Otherwise, they return the name of the attached database, table, 3701 ** or column that query result column was extracted from. 3702 ** 3703 ** ^As with all other SQLite APIs, those whose names end with "16" return 3704 ** UTF-16 encoded strings and the other functions return UTF-8. 3705 ** 3706 ** ^These APIs are only available if the library was compiled with the 3707 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3708 ** 3709 ** If two or more threads call one or more of these routines against the same 3710 ** prepared statement and column at the same time then the results are 3711 ** undefined. 3712 ** 3713 ** If two or more threads call one or more 3714 ** [sqlite3_column_database_name | column metadata interfaces] 3715 ** for the same [prepared statement] and result column 3716 ** at the same time then the results are undefined. 3717 */ 3718 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int); 3719 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int); 3720 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int); 3721 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int); 3722 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int); 3723 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int); 3724 3725 /* 3726 ** CAPI3REF: Declared Datatype Of A Query Result 3727 ** METHOD: sqlite3_stmt 3728 ** 3729 ** ^(The first parameter is a [prepared statement]. 3730 ** If this statement is a [SELECT] statement and the Nth column of the 3731 ** returned result set of that [SELECT] is a table column (not an 3732 ** expression or subquery) then the declared type of the table 3733 ** column is returned.)^ ^If the Nth column of the result set is an 3734 ** expression or subquery, then a NULL pointer is returned. 3735 ** ^The returned string is always UTF-8 encoded. 3736 ** 3737 ** ^(For example, given the database schema: 3738 ** 3739 ** CREATE TABLE t1(c1 VARIANT); 3740 ** 3741 ** and the following statement to be compiled: 3742 ** 3743 ** SELECT c1 + 1, c1 FROM t1; 3744 ** 3745 ** this routine would return the string "VARIANT" for the second result 3746 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3747 ** 3748 ** ^SQLite uses dynamic run-time typing. ^So just because a column 3749 ** is declared to contain a particular type does not mean that the 3750 ** data stored in that column is of the declared type. SQLite is 3751 ** strongly typed, but the typing is dynamic not static. ^Type 3752 ** is associated with individual values, not with the containers 3753 ** used to hold those values. 3754 */ 3755 SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int); 3756 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int); 3757 3758 /* 3759 ** CAPI3REF: Evaluate An SQL Statement 3760 ** METHOD: sqlite3_stmt 3761 ** 3762 ** After a [prepared statement] has been prepared using either 3763 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3764 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3765 ** must be called one or more times to evaluate the statement. 3766 ** 3767 ** The details of the behavior of the sqlite3_step() interface depend 3768 ** on whether the statement was prepared using the newer "v2" interface 3769 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3770 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3771 ** new "v2" interface is recommended for new applications but the legacy 3772 ** interface will continue to be supported. 3773 ** 3774 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3775 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3776 ** ^With the "v2" interface, any of the other [result codes] or 3777 ** [extended result codes] might be returned as well. 3778 ** 3779 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3780 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 3781 ** or occurs outside of an explicit transaction, then you can retry the 3782 ** statement. If the statement is not a [COMMIT] and occurs within an 3783 ** explicit transaction then you should rollback the transaction before 3784 ** continuing. 3785 ** 3786 ** ^[SQLITE_DONE] means that the statement has finished executing 3787 ** successfully. sqlite3_step() should not be called again on this virtual 3788 ** machine without first calling [sqlite3_reset()] to reset the virtual 3789 ** machine back to its initial state. 3790 ** 3791 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3792 ** is returned each time a new row of data is ready for processing by the 3793 ** caller. The values may be accessed using the [column access functions]. 3794 ** sqlite3_step() is called again to retrieve the next row of data. 3795 ** 3796 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3797 ** violation) has occurred. sqlite3_step() should not be called again on 3798 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 3799 ** ^With the legacy interface, a more specific error code (for example, 3800 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3801 ** can be obtained by calling [sqlite3_reset()] on the 3802 ** [prepared statement]. ^In the "v2" interface, 3803 ** the more specific error code is returned directly by sqlite3_step(). 3804 ** 3805 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3806 ** Perhaps it was called on a [prepared statement] that has 3807 ** already been [sqlite3_finalize | finalized] or on one that had 3808 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3809 ** be the case that the same database connection is being used by two or 3810 ** more threads at the same moment in time. 3811 ** 3812 ** For all versions of SQLite up to and including 3.6.23.1, a call to 3813 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 3814 ** other than [SQLITE_ROW] before any subsequent invocation of 3815 ** sqlite3_step(). Failure to reset the prepared statement using 3816 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3817 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3818 ** calling [sqlite3_reset()] automatically in this circumstance rather 3819 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3820 ** break because any application that ever receives an SQLITE_MISUSE error 3821 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3822 ** can be used to restore the legacy behavior. 3823 ** 3824 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3825 ** API always returns a generic error code, [SQLITE_ERROR], following any 3826 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3827 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3828 ** specific [error codes] that better describes the error. 3829 ** We admit that this is a goofy design. The problem has been fixed 3830 ** with the "v2" interface. If you prepare all of your SQL statements 3831 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3832 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3833 ** then the more specific [error codes] are returned directly 3834 ** by sqlite3_step(). The use of the "v2" interface is recommended. 3835 */ 3836 SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*); 3837 3838 /* 3839 ** CAPI3REF: Number of columns in a result set 3840 ** METHOD: sqlite3_stmt 3841 ** 3842 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 3843 ** current row of the result set of [prepared statement] P. 3844 ** ^If prepared statement P does not have results ready to return 3845 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3846 ** interfaces) then sqlite3_data_count(P) returns 0. 3847 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3848 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3849 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3850 ** will return non-zero if previous call to [sqlite3_step](P) returned 3851 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3852 ** where it always returns zero since each step of that multi-step 3853 ** pragma returns 0 columns of data. 3854 ** 3855 ** See also: [sqlite3_column_count()] 3856 */ 3857 SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt); 3858 3859 /* 3860 ** CAPI3REF: Fundamental Datatypes 3861 ** KEYWORDS: SQLITE_TEXT 3862 ** 3863 ** ^(Every value in SQLite has one of five fundamental datatypes: 3864 ** 3865 ** <ul> 3866 ** <li> 64-bit signed integer 3867 ** <li> 64-bit IEEE floating point number 3868 ** <li> string 3869 ** <li> BLOB 3870 ** <li> NULL 3871 ** </ul>)^ 3872 ** 3873 ** These constants are codes for each of those types. 3874 ** 3875 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3876 ** for a completely different meaning. Software that links against both 3877 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3878 ** SQLITE_TEXT. 3879 */ 3880 #define SQLITE_INTEGER 1 3881 #define SQLITE_FLOAT 2 3882 #define SQLITE_BLOB 4 3883 #define SQLITE_NULL 5 3884 #ifdef SQLITE_TEXT 3885 # undef SQLITE_TEXT 3886 #else 3887 # define SQLITE_TEXT 3 3888 #endif 3889 #define SQLITE3_TEXT 3 3890 3891 /* 3892 ** CAPI3REF: Result Values From A Query 3893 ** KEYWORDS: {column access functions} 3894 ** METHOD: sqlite3_stmt 3895 ** 3896 ** These routines form the "result set" interface. 3897 ** 3898 ** ^These routines return information about a single column of the current 3899 ** result row of a query. ^In every case the first argument is a pointer 3900 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3901 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3902 ** and the second argument is the index of the column for which information 3903 ** should be returned. ^The leftmost column of the result set has the index 0. 3904 ** ^The number of columns in the result can be determined using 3905 ** [sqlite3_column_count()]. 3906 ** 3907 ** If the SQL statement does not currently point to a valid row, or if the 3908 ** column index is out of range, the result is undefined. 3909 ** These routines may only be called when the most recent call to 3910 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3911 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3912 ** If any of these routines are called after [sqlite3_reset()] or 3913 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3914 ** something other than [SQLITE_ROW], the results are undefined. 3915 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3916 ** are called from a different thread while any of these routines 3917 ** are pending, then the results are undefined. 3918 ** 3919 ** ^The sqlite3_column_type() routine returns the 3920 ** [SQLITE_INTEGER | datatype code] for the initial data type 3921 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3922 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3923 ** returned by sqlite3_column_type() is only meaningful if no type 3924 ** conversions have occurred as described below. After a type conversion, 3925 ** the value returned by sqlite3_column_type() is undefined. Future 3926 ** versions of SQLite may change the behavior of sqlite3_column_type() 3927 ** following a type conversion. 3928 ** 3929 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3930 ** routine returns the number of bytes in that BLOB or string. 3931 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3932 ** the string to UTF-8 and then returns the number of bytes. 3933 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 3934 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3935 ** the number of bytes in that string. 3936 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3937 ** 3938 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3939 ** routine returns the number of bytes in that BLOB or string. 3940 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3941 ** the string to UTF-16 and then returns the number of bytes. 3942 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3943 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3944 ** the number of bytes in that string. 3945 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3946 ** 3947 ** ^The values returned by [sqlite3_column_bytes()] and 3948 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3949 ** of the string. ^For clarity: the values returned by 3950 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3951 ** bytes in the string, not the number of characters. 3952 ** 3953 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3954 ** even empty strings, are always zero-terminated. ^The return 3955 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3956 ** 3957 ** ^The object returned by [sqlite3_column_value()] is an 3958 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3959 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3960 ** If the [unprotected sqlite3_value] object returned by 3961 ** [sqlite3_column_value()] is used in any other way, including calls 3962 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3963 ** or [sqlite3_value_bytes()], then the behavior is undefined. 3964 ** 3965 ** These routines attempt to convert the value where appropriate. ^For 3966 ** example, if the internal representation is FLOAT and a text result 3967 ** is requested, [sqlite3_snprintf()] is used internally to perform the 3968 ** conversion automatically. ^(The following table details the conversions 3969 ** that are applied: 3970 ** 3971 ** <blockquote> 3972 ** <table border="1"> 3973 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3974 ** 3975 ** <tr><td> NULL <td> INTEGER <td> Result is 0 3976 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3977 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3978 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3979 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3980 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3981 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3982 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3983 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3984 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3985 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 3986 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 3987 ** <tr><td> TEXT <td> BLOB <td> No change 3988 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 3989 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 3990 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3991 ** </table> 3992 ** </blockquote>)^ 3993 ** 3994 ** The table above makes reference to standard C library functions atoi() 3995 ** and atof(). SQLite does not really use these functions. It has its 3996 ** own equivalent internal routines. The atoi() and atof() names are 3997 ** used in the table for brevity and because they are familiar to most 3998 ** C programmers. 3999 ** 4000 ** Note that when type conversions occur, pointers returned by prior 4001 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4002 ** sqlite3_column_text16() may be invalidated. 4003 ** Type conversions and pointer invalidations might occur 4004 ** in the following cases: 4005 ** 4006 ** <ul> 4007 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4008 ** sqlite3_column_text16() is called. A zero-terminator might 4009 ** need to be added to the string.</li> 4010 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4011 ** sqlite3_column_text16() is called. The content must be converted 4012 ** to UTF-16.</li> 4013 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4014 ** sqlite3_column_text() is called. The content must be converted 4015 ** to UTF-8.</li> 4016 ** </ul> 4017 ** 4018 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4019 ** not invalidate a prior pointer, though of course the content of the buffer 4020 ** that the prior pointer references will have been modified. Other kinds 4021 ** of conversion are done in place when it is possible, but sometimes they 4022 ** are not possible and in those cases prior pointers are invalidated. 4023 ** 4024 ** The safest and easiest to remember policy is to invoke these routines 4025 ** in one of the following ways: 4026 ** 4027 ** <ul> 4028 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4029 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4030 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4031 ** </ul> 4032 ** 4033 ** In other words, you should call sqlite3_column_text(), 4034 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4035 ** into the desired format, then invoke sqlite3_column_bytes() or 4036 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4037 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4038 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4039 ** with calls to sqlite3_column_bytes(). 4040 ** 4041 ** ^The pointers returned are valid until a type conversion occurs as 4042 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4043 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4044 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 4045 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4046 ** [sqlite3_free()]. 4047 ** 4048 ** ^(If a memory allocation error occurs during the evaluation of any 4049 ** of these routines, a default value is returned. The default value 4050 ** is either the integer 0, the floating point number 0.0, or a NULL 4051 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4052 ** [SQLITE_NOMEM].)^ 4053 */ 4054 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol); 4055 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4056 SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4057 SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol); 4058 SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol); 4059 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol); 4060 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol); 4061 SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol); 4062 SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol); 4063 SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol); 4064 4065 /* 4066 ** CAPI3REF: Destroy A Prepared Statement Object 4067 ** DESTRUCTOR: sqlite3_stmt 4068 ** 4069 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4070 ** ^If the most recent evaluation of the statement encountered no errors 4071 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4072 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4073 ** sqlite3_finalize(S) returns the appropriate [error code] or 4074 ** [extended error code]. 4075 ** 4076 ** ^The sqlite3_finalize(S) routine can be called at any point during 4077 ** the life cycle of [prepared statement] S: 4078 ** before statement S is ever evaluated, after 4079 ** one or more calls to [sqlite3_reset()], or after any call 4080 ** to [sqlite3_step()] regardless of whether or not the statement has 4081 ** completed execution. 4082 ** 4083 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4084 ** 4085 ** The application must finalize every [prepared statement] in order to avoid 4086 ** resource leaks. It is a grievous error for the application to try to use 4087 ** a prepared statement after it has been finalized. Any use of a prepared 4088 ** statement after it has been finalized can result in undefined and 4089 ** undesirable behavior such as segfaults and heap corruption. 4090 */ 4091 SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt); 4092 4093 /* 4094 ** CAPI3REF: Reset A Prepared Statement Object 4095 ** METHOD: sqlite3_stmt 4096 ** 4097 ** The sqlite3_reset() function is called to reset a [prepared statement] 4098 ** object back to its initial state, ready to be re-executed. 4099 ** ^Any SQL statement variables that had values bound to them using 4100 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4101 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4102 ** 4103 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4104 ** back to the beginning of its program. 4105 ** 4106 ** ^If the most recent call to [sqlite3_step(S)] for the 4107 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4108 ** or if [sqlite3_step(S)] has never before been called on S, 4109 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4110 ** 4111 ** ^If the most recent call to [sqlite3_step(S)] for the 4112 ** [prepared statement] S indicated an error, then 4113 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4114 ** 4115 ** ^The [sqlite3_reset(S)] interface does not change the values 4116 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4117 */ 4118 SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt); 4119 4120 /* 4121 ** CAPI3REF: Create Or Redefine SQL Functions 4122 ** KEYWORDS: {function creation routines} 4123 ** KEYWORDS: {application-defined SQL function} 4124 ** KEYWORDS: {application-defined SQL functions} 4125 ** METHOD: sqlite3 4126 ** 4127 ** ^These functions (collectively known as "function creation routines") 4128 ** are used to add SQL functions or aggregates or to redefine the behavior 4129 ** of existing SQL functions or aggregates. The only differences between 4130 ** these routines are the text encoding expected for 4131 ** the second parameter (the name of the function being created) 4132 ** and the presence or absence of a destructor callback for 4133 ** the application data pointer. 4134 ** 4135 ** ^The first parameter is the [database connection] to which the SQL 4136 ** function is to be added. ^If an application uses more than one database 4137 ** connection then application-defined SQL functions must be added 4138 ** to each database connection separately. 4139 ** 4140 ** ^The second parameter is the name of the SQL function to be created or 4141 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4142 ** representation, exclusive of the zero-terminator. ^Note that the name 4143 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4144 ** ^Any attempt to create a function with a longer name 4145 ** will result in [SQLITE_MISUSE] being returned. 4146 ** 4147 ** ^The third parameter (nArg) 4148 ** is the number of arguments that the SQL function or 4149 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4150 ** aggregate may take any number of arguments between 0 and the limit 4151 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4152 ** parameter is less than -1 or greater than 127 then the behavior is 4153 ** undefined. 4154 ** 4155 ** ^The fourth parameter, eTextRep, specifies what 4156 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4157 ** its parameters. The application should set this parameter to 4158 ** [SQLITE_UTF16LE] if the function implementation invokes 4159 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4160 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4161 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4162 ** otherwise. ^The same SQL function may be registered multiple times using 4163 ** different preferred text encodings, with different implementations for 4164 ** each encoding. 4165 ** ^When multiple implementations of the same function are available, SQLite 4166 ** will pick the one that involves the least amount of data conversion. 4167 ** 4168 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4169 ** to signal that the function will always return the same result given 4170 ** the same inputs within a single SQL statement. Most SQL functions are 4171 ** deterministic. The built-in [random()] SQL function is an example of a 4172 ** function that is not deterministic. The SQLite query planner is able to 4173 ** perform additional optimizations on deterministic functions, so use 4174 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4175 ** 4176 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4177 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4178 ** 4179 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4180 ** pointers to C-language functions that implement the SQL function or 4181 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4182 ** callback only; NULL pointers must be passed as the xStep and xFinal 4183 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4184 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4185 ** SQL function or aggregate, pass NULL pointers for all three function 4186 ** callbacks. 4187 ** 4188 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4189 ** then it is destructor for the application data pointer. 4190 ** The destructor is invoked when the function is deleted, either by being 4191 ** overloaded or when the database connection closes.)^ 4192 ** ^The destructor is also invoked if the call to 4193 ** sqlite3_create_function_v2() fails. 4194 ** ^When the destructor callback of the tenth parameter is invoked, it 4195 ** is passed a single argument which is a copy of the application data 4196 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4197 ** 4198 ** ^It is permitted to register multiple implementations of the same 4199 ** functions with the same name but with either differing numbers of 4200 ** arguments or differing preferred text encodings. ^SQLite will use 4201 ** the implementation that most closely matches the way in which the 4202 ** SQL function is used. ^A function implementation with a non-negative 4203 ** nArg parameter is a better match than a function implementation with 4204 ** a negative nArg. ^A function where the preferred text encoding 4205 ** matches the database encoding is a better 4206 ** match than a function where the encoding is different. 4207 ** ^A function where the encoding difference is between UTF16le and UTF16be 4208 ** is a closer match than a function where the encoding difference is 4209 ** between UTF8 and UTF16. 4210 ** 4211 ** ^Built-in functions may be overloaded by new application-defined functions. 4212 ** 4213 ** ^An application-defined function is permitted to call other 4214 ** SQLite interfaces. However, such calls must not 4215 ** close the database connection nor finalize or reset the prepared 4216 ** statement in which the function is running. 4217 */ 4218 SQLITE_API int SQLITE_STDCALL sqlite3_create_function( 4219 sqlite3 *db, 4220 const char *zFunctionName, 4221 int nArg, 4222 int eTextRep, 4223 void *pApp, 4224 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4225 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4226 void (*xFinal)(sqlite3_context*) 4227 ); 4228 SQLITE_API int SQLITE_STDCALL sqlite3_create_function16( 4229 sqlite3 *db, 4230 const void *zFunctionName, 4231 int nArg, 4232 int eTextRep, 4233 void *pApp, 4234 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4235 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4236 void (*xFinal)(sqlite3_context*) 4237 ); 4238 SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2( 4239 sqlite3 *db, 4240 const char *zFunctionName, 4241 int nArg, 4242 int eTextRep, 4243 void *pApp, 4244 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4245 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4246 void (*xFinal)(sqlite3_context*), 4247 void(*xDestroy)(void*) 4248 ); 4249 4250 /* 4251 ** CAPI3REF: Text Encodings 4252 ** 4253 ** These constant define integer codes that represent the various 4254 ** text encodings supported by SQLite. 4255 */ 4256 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4257 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4258 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4259 #define SQLITE_UTF16 4 /* Use native byte order */ 4260 #define SQLITE_ANY 5 /* Deprecated */ 4261 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4262 4263 /* 4264 ** CAPI3REF: Function Flags 4265 ** 4266 ** These constants may be ORed together with the 4267 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4268 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4269 ** [sqlite3_create_function_v2()]. 4270 */ 4271 #define SQLITE_DETERMINISTIC 0x800 4272 4273 /* 4274 ** CAPI3REF: Deprecated Functions 4275 ** DEPRECATED 4276 ** 4277 ** These functions are [deprecated]. In order to maintain 4278 ** backwards compatibility with older code, these functions continue 4279 ** to be supported. However, new applications should avoid 4280 ** the use of these functions. To encourage programmers to avoid 4281 ** these functions, we will not explain what they do. 4282 */ 4283 #ifndef SQLITE_OMIT_DEPRECATED 4284 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*); 4285 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*); 4286 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4287 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void); 4288 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void); 4289 SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4290 void*,sqlite3_int64); 4291 #endif 4292 4293 /* 4294 ** CAPI3REF: Obtaining SQL Function Parameter Values 4295 ** METHOD: sqlite3_value 4296 ** 4297 ** The C-language implementation of SQL functions and aggregates uses 4298 ** this set of interface routines to access the parameter values on 4299 ** the function or aggregate. 4300 ** 4301 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4302 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4303 ** define callbacks that implement the SQL functions and aggregates. 4304 ** The 3rd parameter to these callbacks is an array of pointers to 4305 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4306 ** each parameter to the SQL function. These routines are used to 4307 ** extract values from the [sqlite3_value] objects. 4308 ** 4309 ** These routines work only with [protected sqlite3_value] objects. 4310 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4311 ** object results in undefined behavior. 4312 ** 4313 ** ^These routines work just like the corresponding [column access functions] 4314 ** except that these routines take a single [protected sqlite3_value] object 4315 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4316 ** 4317 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4318 ** in the native byte-order of the host machine. ^The 4319 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4320 ** extract UTF-16 strings as big-endian and little-endian respectively. 4321 ** 4322 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4323 ** numeric affinity to the value. This means that an attempt is 4324 ** made to convert the value to an integer or floating point. If 4325 ** such a conversion is possible without loss of information (in other 4326 ** words, if the value is a string that looks like a number) 4327 ** then the conversion is performed. Otherwise no conversion occurs. 4328 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4329 ** 4330 ** Please pay particular attention to the fact that the pointer returned 4331 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4332 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4333 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4334 ** or [sqlite3_value_text16()]. 4335 ** 4336 ** These routines must be called from the same thread as 4337 ** the SQL function that supplied the [sqlite3_value*] parameters. 4338 */ 4339 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*); 4340 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*); 4341 SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*); 4342 SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*); 4343 SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*); 4344 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*); 4345 SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*); 4346 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*); 4347 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*); 4348 SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*); 4349 SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*); 4350 SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*); 4351 4352 /* 4353 ** CAPI3REF: Obtain Aggregate Function Context 4354 ** METHOD: sqlite3_context 4355 ** 4356 ** Implementations of aggregate SQL functions use this 4357 ** routine to allocate memory for storing their state. 4358 ** 4359 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4360 ** for a particular aggregate function, SQLite 4361 ** allocates N of memory, zeroes out that memory, and returns a pointer 4362 ** to the new memory. ^On second and subsequent calls to 4363 ** sqlite3_aggregate_context() for the same aggregate function instance, 4364 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4365 ** called once for each invocation of the xStep callback and then one 4366 ** last time when the xFinal callback is invoked. ^(When no rows match 4367 ** an aggregate query, the xStep() callback of the aggregate function 4368 ** implementation is never called and xFinal() is called exactly once. 4369 ** In those cases, sqlite3_aggregate_context() might be called for the 4370 ** first time from within xFinal().)^ 4371 ** 4372 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4373 ** when first called if N is less than or equal to zero or if a memory 4374 ** allocate error occurs. 4375 ** 4376 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4377 ** determined by the N parameter on first successful call. Changing the 4378 ** value of N in subsequent call to sqlite3_aggregate_context() within 4379 ** the same aggregate function instance will not resize the memory 4380 ** allocation.)^ Within the xFinal callback, it is customary to set 4381 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4382 ** pointless memory allocations occur. 4383 ** 4384 ** ^SQLite automatically frees the memory allocated by 4385 ** sqlite3_aggregate_context() when the aggregate query concludes. 4386 ** 4387 ** The first parameter must be a copy of the 4388 ** [sqlite3_context | SQL function context] that is the first parameter 4389 ** to the xStep or xFinal callback routine that implements the aggregate 4390 ** function. 4391 ** 4392 ** This routine must be called from the same thread in which 4393 ** the aggregate SQL function is running. 4394 */ 4395 SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4396 4397 /* 4398 ** CAPI3REF: User Data For Functions 4399 ** METHOD: sqlite3_context 4400 ** 4401 ** ^The sqlite3_user_data() interface returns a copy of 4402 ** the pointer that was the pUserData parameter (the 5th parameter) 4403 ** of the [sqlite3_create_function()] 4404 ** and [sqlite3_create_function16()] routines that originally 4405 ** registered the application defined function. 4406 ** 4407 ** This routine must be called from the same thread in which 4408 ** the application-defined function is running. 4409 */ 4410 SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*); 4411 4412 /* 4413 ** CAPI3REF: Database Connection For Functions 4414 ** METHOD: sqlite3_context 4415 ** 4416 ** ^The sqlite3_context_db_handle() interface returns a copy of 4417 ** the pointer to the [database connection] (the 1st parameter) 4418 ** of the [sqlite3_create_function()] 4419 ** and [sqlite3_create_function16()] routines that originally 4420 ** registered the application defined function. 4421 */ 4422 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*); 4423 4424 /* 4425 ** CAPI3REF: Function Auxiliary Data 4426 ** METHOD: sqlite3_context 4427 ** 4428 ** These functions may be used by (non-aggregate) SQL functions to 4429 ** associate metadata with argument values. If the same value is passed to 4430 ** multiple invocations of the same SQL function during query execution, under 4431 ** some circumstances the associated metadata may be preserved. An example 4432 ** of where this might be useful is in a regular-expression matching 4433 ** function. The compiled version of the regular expression can be stored as 4434 ** metadata associated with the pattern string. 4435 ** Then as long as the pattern string remains the same, 4436 ** the compiled regular expression can be reused on multiple 4437 ** invocations of the same function. 4438 ** 4439 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4440 ** associated by the sqlite3_set_auxdata() function with the Nth argument 4441 ** value to the application-defined function. ^If there is no metadata 4442 ** associated with the function argument, this sqlite3_get_auxdata() interface 4443 ** returns a NULL pointer. 4444 ** 4445 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4446 ** argument of the application-defined function. ^Subsequent 4447 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4448 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4449 ** NULL if the metadata has been discarded. 4450 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4451 ** SQLite will invoke the destructor function X with parameter P exactly 4452 ** once, when the metadata is discarded. 4453 ** SQLite is free to discard the metadata at any time, including: <ul> 4454 ** <li> when the corresponding function parameter changes, or 4455 ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4456 ** SQL statement, or 4457 ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4458 ** <li> during the original sqlite3_set_auxdata() call when a memory 4459 ** allocation error occurs. </ul>)^ 4460 ** 4461 ** Note the last bullet in particular. The destructor X in 4462 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4463 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4464 ** should be called near the end of the function implementation and the 4465 ** function implementation should not make any use of P after 4466 ** sqlite3_set_auxdata() has been called. 4467 ** 4468 ** ^(In practice, metadata is preserved between function calls for 4469 ** function parameters that are compile-time constants, including literal 4470 ** values and [parameters] and expressions composed from the same.)^ 4471 ** 4472 ** These routines must be called from the same thread in which 4473 ** the SQL function is running. 4474 */ 4475 SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N); 4476 SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4477 4478 4479 /* 4480 ** CAPI3REF: Constants Defining Special Destructor Behavior 4481 ** 4482 ** These are special values for the destructor that is passed in as the 4483 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4484 ** argument is SQLITE_STATIC, it means that the content pointer is constant 4485 ** and will never change. It does not need to be destroyed. ^The 4486 ** SQLITE_TRANSIENT value means that the content will likely change in 4487 ** the near future and that SQLite should make its own private copy of 4488 ** the content before returning. 4489 ** 4490 ** The typedef is necessary to work around problems in certain 4491 ** C++ compilers. 4492 */ 4493 typedef void (*sqlite3_destructor_type)(void*); 4494 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4495 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4496 4497 /* 4498 ** CAPI3REF: Setting The Result Of An SQL Function 4499 ** METHOD: sqlite3_context 4500 ** 4501 ** These routines are used by the xFunc or xFinal callbacks that 4502 ** implement SQL functions and aggregates. See 4503 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4504 ** for additional information. 4505 ** 4506 ** These functions work very much like the [parameter binding] family of 4507 ** functions used to bind values to host parameters in prepared statements. 4508 ** Refer to the [SQL parameter] documentation for additional information. 4509 ** 4510 ** ^The sqlite3_result_blob() interface sets the result from 4511 ** an application-defined function to be the BLOB whose content is pointed 4512 ** to by the second parameter and which is N bytes long where N is the 4513 ** third parameter. 4514 ** 4515 ** ^The sqlite3_result_zeroblob() interfaces set the result of 4516 ** the application-defined function to be a BLOB containing all zero 4517 ** bytes and N bytes in size, where N is the value of the 2nd parameter. 4518 ** 4519 ** ^The sqlite3_result_double() interface sets the result from 4520 ** an application-defined function to be a floating point value specified 4521 ** by its 2nd argument. 4522 ** 4523 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4524 ** cause the implemented SQL function to throw an exception. 4525 ** ^SQLite uses the string pointed to by the 4526 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4527 ** as the text of an error message. ^SQLite interprets the error 4528 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4529 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4530 ** byte order. ^If the third parameter to sqlite3_result_error() 4531 ** or sqlite3_result_error16() is negative then SQLite takes as the error 4532 ** message all text up through the first zero character. 4533 ** ^If the third parameter to sqlite3_result_error() or 4534 ** sqlite3_result_error16() is non-negative then SQLite takes that many 4535 ** bytes (not characters) from the 2nd parameter as the error message. 4536 ** ^The sqlite3_result_error() and sqlite3_result_error16() 4537 ** routines make a private copy of the error message text before 4538 ** they return. Hence, the calling function can deallocate or 4539 ** modify the text after they return without harm. 4540 ** ^The sqlite3_result_error_code() function changes the error code 4541 ** returned by SQLite as a result of an error in a function. ^By default, 4542 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4543 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4544 ** 4545 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4546 ** error indicating that a string or BLOB is too long to represent. 4547 ** 4548 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4549 ** error indicating that a memory allocation failed. 4550 ** 4551 ** ^The sqlite3_result_int() interface sets the return value 4552 ** of the application-defined function to be the 32-bit signed integer 4553 ** value given in the 2nd argument. 4554 ** ^The sqlite3_result_int64() interface sets the return value 4555 ** of the application-defined function to be the 64-bit signed integer 4556 ** value given in the 2nd argument. 4557 ** 4558 ** ^The sqlite3_result_null() interface sets the return value 4559 ** of the application-defined function to be NULL. 4560 ** 4561 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4562 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4563 ** set the return value of the application-defined function to be 4564 ** a text string which is represented as UTF-8, UTF-16 native byte order, 4565 ** UTF-16 little endian, or UTF-16 big endian, respectively. 4566 ** ^The sqlite3_result_text64() interface sets the return value of an 4567 ** application-defined function to be a text string in an encoding 4568 ** specified by the fifth (and last) parameter, which must be one 4569 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4570 ** ^SQLite takes the text result from the application from 4571 ** the 2nd parameter of the sqlite3_result_text* interfaces. 4572 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4573 ** is negative, then SQLite takes result text from the 2nd parameter 4574 ** through the first zero character. 4575 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4576 ** is non-negative, then as many bytes (not characters) of the text 4577 ** pointed to by the 2nd parameter are taken as the application-defined 4578 ** function result. If the 3rd parameter is non-negative, then it 4579 ** must be the byte offset into the string where the NUL terminator would 4580 ** appear if the string where NUL terminated. If any NUL characters occur 4581 ** in the string at a byte offset that is less than the value of the 3rd 4582 ** parameter, then the resulting string will contain embedded NULs and the 4583 ** result of expressions operating on strings with embedded NULs is undefined. 4584 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4585 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4586 ** function as the destructor on the text or BLOB result when it has 4587 ** finished using that result. 4588 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4589 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4590 ** assumes that the text or BLOB result is in constant space and does not 4591 ** copy the content of the parameter nor call a destructor on the content 4592 ** when it has finished using that result. 4593 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4594 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4595 ** then SQLite makes a copy of the result into space obtained from 4596 ** from [sqlite3_malloc()] before it returns. 4597 ** 4598 ** ^The sqlite3_result_value() interface sets the result of 4599 ** the application-defined function to be a copy the 4600 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4601 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4602 ** so that the [sqlite3_value] specified in the parameter may change or 4603 ** be deallocated after sqlite3_result_value() returns without harm. 4604 ** ^A [protected sqlite3_value] object may always be used where an 4605 ** [unprotected sqlite3_value] object is required, so either 4606 ** kind of [sqlite3_value] object can be used with this interface. 4607 ** 4608 ** If these routines are called from within the different thread 4609 ** than the one containing the application-defined function that received 4610 ** the [sqlite3_context] pointer, the results are undefined. 4611 */ 4612 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4613 SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*, 4614 sqlite3_uint64,void(*)(void*)); 4615 SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double); 4616 SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int); 4617 SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int); 4618 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*); 4619 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*); 4620 SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int); 4621 SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int); 4622 SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4623 SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*); 4624 SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4625 SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4626 void(*)(void*), unsigned char encoding); 4627 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4628 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4629 SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4630 SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4631 SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n); 4632 4633 /* 4634 ** CAPI3REF: Define New Collating Sequences 4635 ** METHOD: sqlite3 4636 ** 4637 ** ^These functions add, remove, or modify a [collation] associated 4638 ** with the [database connection] specified as the first argument. 4639 ** 4640 ** ^The name of the collation is a UTF-8 string 4641 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4642 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4643 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4644 ** considered to be the same name. 4645 ** 4646 ** ^(The third argument (eTextRep) must be one of the constants: 4647 ** <ul> 4648 ** <li> [SQLITE_UTF8], 4649 ** <li> [SQLITE_UTF16LE], 4650 ** <li> [SQLITE_UTF16BE], 4651 ** <li> [SQLITE_UTF16], or 4652 ** <li> [SQLITE_UTF16_ALIGNED]. 4653 ** </ul>)^ 4654 ** ^The eTextRep argument determines the encoding of strings passed 4655 ** to the collating function callback, xCallback. 4656 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4657 ** force strings to be UTF16 with native byte order. 4658 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4659 ** on an even byte address. 4660 ** 4661 ** ^The fourth argument, pArg, is an application data pointer that is passed 4662 ** through as the first argument to the collating function callback. 4663 ** 4664 ** ^The fifth argument, xCallback, is a pointer to the collating function. 4665 ** ^Multiple collating functions can be registered using the same name but 4666 ** with different eTextRep parameters and SQLite will use whichever 4667 ** function requires the least amount of data transformation. 4668 ** ^If the xCallback argument is NULL then the collating function is 4669 ** deleted. ^When all collating functions having the same name are deleted, 4670 ** that collation is no longer usable. 4671 ** 4672 ** ^The collating function callback is invoked with a copy of the pArg 4673 ** application data pointer and with two strings in the encoding specified 4674 ** by the eTextRep argument. The collating function must return an 4675 ** integer that is negative, zero, or positive 4676 ** if the first string is less than, equal to, or greater than the second, 4677 ** respectively. A collating function must always return the same answer 4678 ** given the same inputs. If two or more collating functions are registered 4679 ** to the same collation name (using different eTextRep values) then all 4680 ** must give an equivalent answer when invoked with equivalent strings. 4681 ** The collating function must obey the following properties for all 4682 ** strings A, B, and C: 4683 ** 4684 ** <ol> 4685 ** <li> If A==B then B==A. 4686 ** <li> If A==B and B==C then A==C. 4687 ** <li> If A<B THEN B>A. 4688 ** <li> If A<B and B<C then A<C. 4689 ** </ol> 4690 ** 4691 ** If a collating function fails any of the above constraints and that 4692 ** collating function is registered and used, then the behavior of SQLite 4693 ** is undefined. 4694 ** 4695 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4696 ** with the addition that the xDestroy callback is invoked on pArg when 4697 ** the collating function is deleted. 4698 ** ^Collating functions are deleted when they are overridden by later 4699 ** calls to the collation creation functions or when the 4700 ** [database connection] is closed using [sqlite3_close()]. 4701 ** 4702 ** ^The xDestroy callback is <u>not</u> called if the 4703 ** sqlite3_create_collation_v2() function fails. Applications that invoke 4704 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4705 ** check the return code and dispose of the application data pointer 4706 ** themselves rather than expecting SQLite to deal with it for them. 4707 ** This is different from every other SQLite interface. The inconsistency 4708 ** is unfortunate but cannot be changed without breaking backwards 4709 ** compatibility. 4710 ** 4711 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4712 */ 4713 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation( 4714 sqlite3*, 4715 const char *zName, 4716 int eTextRep, 4717 void *pArg, 4718 int(*xCompare)(void*,int,const void*,int,const void*) 4719 ); 4720 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2( 4721 sqlite3*, 4722 const char *zName, 4723 int eTextRep, 4724 void *pArg, 4725 int(*xCompare)(void*,int,const void*,int,const void*), 4726 void(*xDestroy)(void*) 4727 ); 4728 SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16( 4729 sqlite3*, 4730 const void *zName, 4731 int eTextRep, 4732 void *pArg, 4733 int(*xCompare)(void*,int,const void*,int,const void*) 4734 ); 4735 4736 /* 4737 ** CAPI3REF: Collation Needed Callbacks 4738 ** METHOD: sqlite3 4739 ** 4740 ** ^To avoid having to register all collation sequences before a database 4741 ** can be used, a single callback function may be registered with the 4742 ** [database connection] to be invoked whenever an undefined collation 4743 ** sequence is required. 4744 ** 4745 ** ^If the function is registered using the sqlite3_collation_needed() API, 4746 ** then it is passed the names of undefined collation sequences as strings 4747 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4748 ** the names are passed as UTF-16 in machine native byte order. 4749 ** ^A call to either function replaces the existing collation-needed callback. 4750 ** 4751 ** ^(When the callback is invoked, the first argument passed is a copy 4752 ** of the second argument to sqlite3_collation_needed() or 4753 ** sqlite3_collation_needed16(). The second argument is the database 4754 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4755 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4756 ** sequence function required. The fourth parameter is the name of the 4757 ** required collation sequence.)^ 4758 ** 4759 ** The callback function should register the desired collation using 4760 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4761 ** [sqlite3_create_collation_v2()]. 4762 */ 4763 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed( 4764 sqlite3*, 4765 void*, 4766 void(*)(void*,sqlite3*,int eTextRep,const char*) 4767 ); 4768 SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16( 4769 sqlite3*, 4770 void*, 4771 void(*)(void*,sqlite3*,int eTextRep,const void*) 4772 ); 4773 4774 #ifdef SQLITE_HAS_CODEC 4775 /* 4776 ** Specify the key for an encrypted database. This routine should be 4777 ** called right after sqlite3_open(). 4778 ** 4779 ** The code to implement this API is not available in the public release 4780 ** of SQLite. 4781 */ 4782 SQLITE_API int SQLITE_STDCALL sqlite3_key( 4783 sqlite3 *db, /* Database to be rekeyed */ 4784 const void *pKey, int nKey /* The key */ 4785 ); 4786 SQLITE_API int SQLITE_STDCALL sqlite3_key_v2( 4787 sqlite3 *db, /* Database to be rekeyed */ 4788 const char *zDbName, /* Name of the database */ 4789 const void *pKey, int nKey /* The key */ 4790 ); 4791 4792 /* 4793 ** Change the key on an open database. If the current database is not 4794 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4795 ** database is decrypted. 4796 ** 4797 ** The code to implement this API is not available in the public release 4798 ** of SQLite. 4799 */ 4800 SQLITE_API int SQLITE_STDCALL sqlite3_rekey( 4801 sqlite3 *db, /* Database to be rekeyed */ 4802 const void *pKey, int nKey /* The new key */ 4803 ); 4804 SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2( 4805 sqlite3 *db, /* Database to be rekeyed */ 4806 const char *zDbName, /* Name of the database */ 4807 const void *pKey, int nKey /* The new key */ 4808 ); 4809 4810 /* 4811 ** Specify the activation key for a SEE database. Unless 4812 ** activated, none of the SEE routines will work. 4813 */ 4814 SQLITE_API void SQLITE_STDCALL sqlite3_activate_see( 4815 const char *zPassPhrase /* Activation phrase */ 4816 ); 4817 #endif 4818 4819 #ifdef SQLITE_ENABLE_CEROD 4820 /* 4821 ** Specify the activation key for a CEROD database. Unless 4822 ** activated, none of the CEROD routines will work. 4823 */ 4824 SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod( 4825 const char *zPassPhrase /* Activation phrase */ 4826 ); 4827 #endif 4828 4829 /* 4830 ** CAPI3REF: Suspend Execution For A Short Time 4831 ** 4832 ** The sqlite3_sleep() function causes the current thread to suspend execution 4833 ** for at least a number of milliseconds specified in its parameter. 4834 ** 4835 ** If the operating system does not support sleep requests with 4836 ** millisecond time resolution, then the time will be rounded up to 4837 ** the nearest second. The number of milliseconds of sleep actually 4838 ** requested from the operating system is returned. 4839 ** 4840 ** ^SQLite implements this interface by calling the xSleep() 4841 ** method of the default [sqlite3_vfs] object. If the xSleep() method 4842 ** of the default VFS is not implemented correctly, or not implemented at 4843 ** all, then the behavior of sqlite3_sleep() may deviate from the description 4844 ** in the previous paragraphs. 4845 */ 4846 SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int); 4847 4848 /* 4849 ** CAPI3REF: Name Of The Folder Holding Temporary Files 4850 ** 4851 ** ^(If this global variable is made to point to a string which is 4852 ** the name of a folder (a.k.a. directory), then all temporary files 4853 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4854 ** will be placed in that directory.)^ ^If this variable 4855 ** is a NULL pointer, then SQLite performs a search for an appropriate 4856 ** temporary file directory. 4857 ** 4858 ** Applications are strongly discouraged from using this global variable. 4859 ** It is required to set a temporary folder on Windows Runtime (WinRT). 4860 ** But for all other platforms, it is highly recommended that applications 4861 ** neither read nor write this variable. This global variable is a relic 4862 ** that exists for backwards compatibility of legacy applications and should 4863 ** be avoided in new projects. 4864 ** 4865 ** It is not safe to read or modify this variable in more than one 4866 ** thread at a time. It is not safe to read or modify this variable 4867 ** if a [database connection] is being used at the same time in a separate 4868 ** thread. 4869 ** It is intended that this variable be set once 4870 ** as part of process initialization and before any SQLite interface 4871 ** routines have been called and that this variable remain unchanged 4872 ** thereafter. 4873 ** 4874 ** ^The [temp_store_directory pragma] may modify this variable and cause 4875 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4876 ** the [temp_store_directory pragma] always assumes that any string 4877 ** that this variable points to is held in memory obtained from 4878 ** [sqlite3_malloc] and the pragma may attempt to free that memory 4879 ** using [sqlite3_free]. 4880 ** Hence, if this variable is modified directly, either it should be 4881 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4882 ** or else the use of the [temp_store_directory pragma] should be avoided. 4883 ** Except when requested by the [temp_store_directory pragma], SQLite 4884 ** does not free the memory that sqlite3_temp_directory points to. If 4885 ** the application wants that memory to be freed, it must do 4886 ** so itself, taking care to only do so after all [database connection] 4887 ** objects have been destroyed. 4888 ** 4889 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4890 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4891 ** features that require the use of temporary files may fail. Here is an 4892 ** example of how to do this using C++ with the Windows Runtime: 4893 ** 4894 ** <blockquote><pre> 4895 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4896 ** TemporaryFolder->Path->Data(); 4897 ** char zPathBuf[MAX_PATH + 1]; 4898 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 4899 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4900 ** NULL, NULL); 4901 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4902 ** </pre></blockquote> 4903 */ 4904 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4905 4906 /* 4907 ** CAPI3REF: Name Of The Folder Holding Database Files 4908 ** 4909 ** ^(If this global variable is made to point to a string which is 4910 ** the name of a folder (a.k.a. directory), then all database files 4911 ** specified with a relative pathname and created or accessed by 4912 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4913 ** to be relative to that directory.)^ ^If this variable is a NULL 4914 ** pointer, then SQLite assumes that all database files specified 4915 ** with a relative pathname are relative to the current directory 4916 ** for the process. Only the windows VFS makes use of this global 4917 ** variable; it is ignored by the unix VFS. 4918 ** 4919 ** Changing the value of this variable while a database connection is 4920 ** open can result in a corrupt database. 4921 ** 4922 ** It is not safe to read or modify this variable in more than one 4923 ** thread at a time. It is not safe to read or modify this variable 4924 ** if a [database connection] is being used at the same time in a separate 4925 ** thread. 4926 ** It is intended that this variable be set once 4927 ** as part of process initialization and before any SQLite interface 4928 ** routines have been called and that this variable remain unchanged 4929 ** thereafter. 4930 ** 4931 ** ^The [data_store_directory pragma] may modify this variable and cause 4932 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4933 ** the [data_store_directory pragma] always assumes that any string 4934 ** that this variable points to is held in memory obtained from 4935 ** [sqlite3_malloc] and the pragma may attempt to free that memory 4936 ** using [sqlite3_free]. 4937 ** Hence, if this variable is modified directly, either it should be 4938 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4939 ** or else the use of the [data_store_directory pragma] should be avoided. 4940 */ 4941 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 4942 4943 /* 4944 ** CAPI3REF: Test For Auto-Commit Mode 4945 ** KEYWORDS: {autocommit mode} 4946 ** METHOD: sqlite3 4947 ** 4948 ** ^The sqlite3_get_autocommit() interface returns non-zero or 4949 ** zero if the given database connection is or is not in autocommit mode, 4950 ** respectively. ^Autocommit mode is on by default. 4951 ** ^Autocommit mode is disabled by a [BEGIN] statement. 4952 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4953 ** 4954 ** If certain kinds of errors occur on a statement within a multi-statement 4955 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4956 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4957 ** transaction might be rolled back automatically. The only way to 4958 ** find out whether SQLite automatically rolled back the transaction after 4959 ** an error is to use this function. 4960 ** 4961 ** If another thread changes the autocommit status of the database 4962 ** connection while this routine is running, then the return value 4963 ** is undefined. 4964 */ 4965 SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*); 4966 4967 /* 4968 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 4969 ** METHOD: sqlite3_stmt 4970 ** 4971 ** ^The sqlite3_db_handle interface returns the [database connection] handle 4972 ** to which a [prepared statement] belongs. ^The [database connection] 4973 ** returned by sqlite3_db_handle is the same [database connection] 4974 ** that was the first argument 4975 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4976 ** create the statement in the first place. 4977 */ 4978 SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*); 4979 4980 /* 4981 ** CAPI3REF: Return The Filename For A Database Connection 4982 ** METHOD: sqlite3 4983 ** 4984 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4985 ** associated with database N of connection D. ^The main database file 4986 ** has the name "main". If there is no attached database N on the database 4987 ** connection D, or if database N is a temporary or in-memory database, then 4988 ** a NULL pointer is returned. 4989 ** 4990 ** ^The filename returned by this function is the output of the 4991 ** xFullPathname method of the [VFS]. ^In other words, the filename 4992 ** will be an absolute pathname, even if the filename used 4993 ** to open the database originally was a URI or relative pathname. 4994 */ 4995 SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4996 4997 /* 4998 ** CAPI3REF: Determine if a database is read-only 4999 ** METHOD: sqlite3 5000 ** 5001 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5002 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5003 ** the name of a database on connection D. 5004 */ 5005 SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5006 5007 /* 5008 ** CAPI3REF: Find the next prepared statement 5009 ** METHOD: sqlite3 5010 ** 5011 ** ^This interface returns a pointer to the next [prepared statement] after 5012 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5013 ** then this interface returns a pointer to the first prepared statement 5014 ** associated with the database connection pDb. ^If no prepared statement 5015 ** satisfies the conditions of this routine, it returns NULL. 5016 ** 5017 ** The [database connection] pointer D in a call to 5018 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5019 ** connection and in particular must not be a NULL pointer. 5020 */ 5021 SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5022 5023 /* 5024 ** CAPI3REF: Commit And Rollback Notification Callbacks 5025 ** METHOD: sqlite3 5026 ** 5027 ** ^The sqlite3_commit_hook() interface registers a callback 5028 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5029 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5030 ** for the same database connection is overridden. 5031 ** ^The sqlite3_rollback_hook() interface registers a callback 5032 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5033 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5034 ** for the same database connection is overridden. 5035 ** ^The pArg argument is passed through to the callback. 5036 ** ^If the callback on a commit hook function returns non-zero, 5037 ** then the commit is converted into a rollback. 5038 ** 5039 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5040 ** return the P argument from the previous call of the same function 5041 ** on the same [database connection] D, or NULL for 5042 ** the first call for each function on D. 5043 ** 5044 ** The commit and rollback hook callbacks are not reentrant. 5045 ** The callback implementation must not do anything that will modify 5046 ** the database connection that invoked the callback. Any actions 5047 ** to modify the database connection must be deferred until after the 5048 ** completion of the [sqlite3_step()] call that triggered the commit 5049 ** or rollback hook in the first place. 5050 ** Note that running any other SQL statements, including SELECT statements, 5051 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5052 ** the database connections for the meaning of "modify" in this paragraph. 5053 ** 5054 ** ^Registering a NULL function disables the callback. 5055 ** 5056 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5057 ** operation is allowed to continue normally. ^If the commit hook 5058 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5059 ** ^The rollback hook is invoked on a rollback that results from a commit 5060 ** hook returning non-zero, just as it would be with any other rollback. 5061 ** 5062 ** ^For the purposes of this API, a transaction is said to have been 5063 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5064 ** an error or constraint causes an implicit rollback to occur. 5065 ** ^The rollback callback is not invoked if a transaction is 5066 ** automatically rolled back because the database connection is closed. 5067 ** 5068 ** See also the [sqlite3_update_hook()] interface. 5069 */ 5070 SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5071 SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5072 5073 /* 5074 ** CAPI3REF: Data Change Notification Callbacks 5075 ** METHOD: sqlite3 5076 ** 5077 ** ^The sqlite3_update_hook() interface registers a callback function 5078 ** with the [database connection] identified by the first argument 5079 ** to be invoked whenever a row is updated, inserted or deleted in 5080 ** a rowid table. 5081 ** ^Any callback set by a previous call to this function 5082 ** for the same database connection is overridden. 5083 ** 5084 ** ^The second argument is a pointer to the function to invoke when a 5085 ** row is updated, inserted or deleted in a rowid table. 5086 ** ^The first argument to the callback is a copy of the third argument 5087 ** to sqlite3_update_hook(). 5088 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5089 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5090 ** to be invoked. 5091 ** ^The third and fourth arguments to the callback contain pointers to the 5092 ** database and table name containing the affected row. 5093 ** ^The final callback parameter is the [rowid] of the row. 5094 ** ^In the case of an update, this is the [rowid] after the update takes place. 5095 ** 5096 ** ^(The update hook is not invoked when internal system tables are 5097 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5098 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5099 ** 5100 ** ^In the current implementation, the update hook 5101 ** is not invoked when duplication rows are deleted because of an 5102 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5103 ** invoked when rows are deleted using the [truncate optimization]. 5104 ** The exceptions defined in this paragraph might change in a future 5105 ** release of SQLite. 5106 ** 5107 ** The update hook implementation must not do anything that will modify 5108 ** the database connection that invoked the update hook. Any actions 5109 ** to modify the database connection must be deferred until after the 5110 ** completion of the [sqlite3_step()] call that triggered the update hook. 5111 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5112 ** database connections for the meaning of "modify" in this paragraph. 5113 ** 5114 ** ^The sqlite3_update_hook(D,C,P) function 5115 ** returns the P argument from the previous call 5116 ** on the same [database connection] D, or NULL for 5117 ** the first call on D. 5118 ** 5119 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 5120 ** interfaces. 5121 */ 5122 SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( 5123 sqlite3*, 5124 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5125 void* 5126 ); 5127 5128 /* 5129 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5130 ** 5131 ** ^(This routine enables or disables the sharing of the database cache 5132 ** and schema data structures between [database connection | connections] 5133 ** to the same database. Sharing is enabled if the argument is true 5134 ** and disabled if the argument is false.)^ 5135 ** 5136 ** ^Cache sharing is enabled and disabled for an entire process. 5137 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5138 ** sharing was enabled or disabled for each thread separately. 5139 ** 5140 ** ^(The cache sharing mode set by this interface effects all subsequent 5141 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5142 ** Existing database connections continue use the sharing mode 5143 ** that was in effect at the time they were opened.)^ 5144 ** 5145 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5146 ** successfully. An [error code] is returned otherwise.)^ 5147 ** 5148 ** ^Shared cache is disabled by default. But this might change in 5149 ** future releases of SQLite. Applications that care about shared 5150 ** cache setting should set it explicitly. 5151 ** 5152 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5153 ** and will always return SQLITE_MISUSE. On those systems, 5154 ** shared cache mode should be enabled per-database connection via 5155 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5156 ** 5157 ** This interface is threadsafe on processors where writing a 5158 ** 32-bit integer is atomic. 5159 ** 5160 ** See Also: [SQLite Shared-Cache Mode] 5161 */ 5162 SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int); 5163 5164 /* 5165 ** CAPI3REF: Attempt To Free Heap Memory 5166 ** 5167 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5168 ** of heap memory by deallocating non-essential memory allocations 5169 ** held by the database library. Memory used to cache database 5170 ** pages to improve performance is an example of non-essential memory. 5171 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5172 ** which might be more or less than the amount requested. 5173 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5174 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5175 ** 5176 ** See also: [sqlite3_db_release_memory()] 5177 */ 5178 SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int); 5179 5180 /* 5181 ** CAPI3REF: Free Memory Used By A Database Connection 5182 ** METHOD: sqlite3 5183 ** 5184 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5185 ** memory as possible from database connection D. Unlike the 5186 ** [sqlite3_release_memory()] interface, this interface is in effect even 5187 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5188 ** omitted. 5189 ** 5190 ** See also: [sqlite3_release_memory()] 5191 */ 5192 SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*); 5193 5194 /* 5195 ** CAPI3REF: Impose A Limit On Heap Size 5196 ** 5197 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5198 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5199 ** ^SQLite strives to keep heap memory utilization below the soft heap 5200 ** limit by reducing the number of pages held in the page cache 5201 ** as heap memory usages approaches the limit. 5202 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5203 ** below the limit, it will exceed the limit rather than generate 5204 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5205 ** is advisory only. 5206 ** 5207 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5208 ** the soft heap limit prior to the call, or negative in the case of an 5209 ** error. ^If the argument N is negative 5210 ** then no change is made to the soft heap limit. Hence, the current 5211 ** size of the soft heap limit can be determined by invoking 5212 ** sqlite3_soft_heap_limit64() with a negative argument. 5213 ** 5214 ** ^If the argument N is zero then the soft heap limit is disabled. 5215 ** 5216 ** ^(The soft heap limit is not enforced in the current implementation 5217 ** if one or more of following conditions are true: 5218 ** 5219 ** <ul> 5220 ** <li> The soft heap limit is set to zero. 5221 ** <li> Memory accounting is disabled using a combination of the 5222 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5223 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5224 ** <li> An alternative page cache implementation is specified using 5225 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5226 ** <li> The page cache allocates from its own memory pool supplied 5227 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5228 ** from the heap. 5229 ** </ul>)^ 5230 ** 5231 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5232 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5233 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5234 ** the soft heap limit is enforced on every memory allocation. Without 5235 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5236 ** when memory is allocated by the page cache. Testing suggests that because 5237 ** the page cache is the predominate memory user in SQLite, most 5238 ** applications will achieve adequate soft heap limit enforcement without 5239 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5240 ** 5241 ** The circumstances under which SQLite will enforce the soft heap limit may 5242 ** changes in future releases of SQLite. 5243 */ 5244 SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N); 5245 5246 /* 5247 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5248 ** DEPRECATED 5249 ** 5250 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5251 ** interface. This routine is provided for historical compatibility 5252 ** only. All new applications should use the 5253 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5254 */ 5255 SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N); 5256 5257 5258 /* 5259 ** CAPI3REF: Extract Metadata About A Column Of A Table 5260 ** METHOD: sqlite3 5261 ** 5262 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5263 ** information about column C of table T in database D 5264 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5265 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5266 ** the final five arguments with appropriate values if the specified 5267 ** column exists. ^The sqlite3_table_column_metadata() interface returns 5268 ** SQLITE_ERROR and if the specified column does not exist. 5269 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5270 ** NULL pointer, then this routine simply checks for the existance of the 5271 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5272 ** does not. 5273 ** 5274 ** ^The column is identified by the second, third and fourth parameters to 5275 ** this function. ^(The second parameter is either the name of the database 5276 ** (i.e. "main", "temp", or an attached database) containing the specified 5277 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5278 ** for the table using the same algorithm used by the database engine to 5279 ** resolve unqualified table references. 5280 ** 5281 ** ^The third and fourth parameters to this function are the table and column 5282 ** name of the desired column, respectively. 5283 ** 5284 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5285 ** and subsequent parameters to this function. ^Any of these arguments may be 5286 ** NULL, in which case the corresponding element of metadata is omitted. 5287 ** 5288 ** ^(<blockquote> 5289 ** <table border="1"> 5290 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5291 ** 5292 ** <tr><td> 5th <td> const char* <td> Data type 5293 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5294 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5295 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5296 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5297 ** </table> 5298 ** </blockquote>)^ 5299 ** 5300 ** ^The memory pointed to by the character pointers returned for the 5301 ** declaration type and collation sequence is valid until the next 5302 ** call to any SQLite API function. 5303 ** 5304 ** ^If the specified table is actually a view, an [error code] is returned. 5305 ** 5306 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5307 ** is not a [WITHOUT ROWID] table and an 5308 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5309 ** parameters are set for the explicitly declared column. ^(If there is no 5310 ** [INTEGER PRIMARY KEY] column, then the outputs 5311 ** for the [rowid] are set as follows: 5312 ** 5313 ** <pre> 5314 ** data type: "INTEGER" 5315 ** collation sequence: "BINARY" 5316 ** not null: 0 5317 ** primary key: 1 5318 ** auto increment: 0 5319 ** </pre>)^ 5320 ** 5321 ** ^This function causes all database schemas to be read from disk and 5322 ** parsed, if that has not already been done, and returns an error if 5323 ** any errors are encountered while loading the schema. 5324 */ 5325 SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata( 5326 sqlite3 *db, /* Connection handle */ 5327 const char *zDbName, /* Database name or NULL */ 5328 const char *zTableName, /* Table name */ 5329 const char *zColumnName, /* Column name */ 5330 char const **pzDataType, /* OUTPUT: Declared data type */ 5331 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5332 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5333 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5334 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5335 ); 5336 5337 /* 5338 ** CAPI3REF: Load An Extension 5339 ** METHOD: sqlite3 5340 ** 5341 ** ^This interface loads an SQLite extension library from the named file. 5342 ** 5343 ** ^The sqlite3_load_extension() interface attempts to load an 5344 ** [SQLite extension] library contained in the file zFile. If 5345 ** the file cannot be loaded directly, attempts are made to load 5346 ** with various operating-system specific extensions added. 5347 ** So for example, if "samplelib" cannot be loaded, then names like 5348 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5349 ** be tried also. 5350 ** 5351 ** ^The entry point is zProc. 5352 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5353 ** entry point name on its own. It first tries "sqlite3_extension_init". 5354 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5355 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5356 ** characters in the filename from the last "/" to the first following 5357 ** "." and omitting any initial "lib".)^ 5358 ** ^The sqlite3_load_extension() interface returns 5359 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5360 ** ^If an error occurs and pzErrMsg is not 0, then the 5361 ** [sqlite3_load_extension()] interface shall attempt to 5362 ** fill *pzErrMsg with error message text stored in memory 5363 ** obtained from [sqlite3_malloc()]. The calling function 5364 ** should free this memory by calling [sqlite3_free()]. 5365 ** 5366 ** ^Extension loading must be enabled using 5367 ** [sqlite3_enable_load_extension()] prior to calling this API, 5368 ** otherwise an error will be returned. 5369 ** 5370 ** See also the [load_extension() SQL function]. 5371 */ 5372 SQLITE_API int SQLITE_STDCALL sqlite3_load_extension( 5373 sqlite3 *db, /* Load the extension into this database connection */ 5374 const char *zFile, /* Name of the shared library containing extension */ 5375 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5376 char **pzErrMsg /* Put error message here if not 0 */ 5377 ); 5378 5379 /* 5380 ** CAPI3REF: Enable Or Disable Extension Loading 5381 ** METHOD: sqlite3 5382 ** 5383 ** ^So as not to open security holes in older applications that are 5384 ** unprepared to deal with [extension loading], and as a means of disabling 5385 ** [extension loading] while evaluating user-entered SQL, the following API 5386 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5387 ** 5388 ** ^Extension loading is off by default. 5389 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5390 ** to turn extension loading on and call it with onoff==0 to turn 5391 ** it back off again. 5392 */ 5393 SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5394 5395 /* 5396 ** CAPI3REF: Automatically Load Statically Linked Extensions 5397 ** 5398 ** ^This interface causes the xEntryPoint() function to be invoked for 5399 ** each new [database connection] that is created. The idea here is that 5400 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5401 ** that is to be automatically loaded into all new database connections. 5402 ** 5403 ** ^(Even though the function prototype shows that xEntryPoint() takes 5404 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5405 ** arguments and expects and integer result as if the signature of the 5406 ** entry point where as follows: 5407 ** 5408 ** <blockquote><pre> 5409 ** int xEntryPoint( 5410 ** sqlite3 *db, 5411 ** const char **pzErrMsg, 5412 ** const struct sqlite3_api_routines *pThunk 5413 ** ); 5414 ** </pre></blockquote>)^ 5415 ** 5416 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5417 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5418 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5419 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5420 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5421 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5422 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5423 ** 5424 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5425 ** on the list of automatic extensions is a harmless no-op. ^No entry point 5426 ** will be called more than once for each database connection that is opened. 5427 ** 5428 ** See also: [sqlite3_reset_auto_extension()] 5429 ** and [sqlite3_cancel_auto_extension()] 5430 */ 5431 SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void)); 5432 5433 /* 5434 ** CAPI3REF: Cancel Automatic Extension Loading 5435 ** 5436 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5437 ** initialization routine X that was registered using a prior call to 5438 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5439 ** routine returns 1 if initialization routine X was successfully 5440 ** unregistered and it returns 0 if X was not on the list of initialization 5441 ** routines. 5442 */ 5443 SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5444 5445 /* 5446 ** CAPI3REF: Reset Automatic Extension Loading 5447 ** 5448 ** ^This interface disables all automatic extensions previously 5449 ** registered using [sqlite3_auto_extension()]. 5450 */ 5451 SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void); 5452 5453 /* 5454 ** The interface to the virtual-table mechanism is currently considered 5455 ** to be experimental. The interface might change in incompatible ways. 5456 ** If this is a problem for you, do not use the interface at this time. 5457 ** 5458 ** When the virtual-table mechanism stabilizes, we will declare the 5459 ** interface fixed, support it indefinitely, and remove this comment. 5460 */ 5461 5462 /* 5463 ** Structures used by the virtual table interface 5464 */ 5465 typedef struct sqlite3_vtab sqlite3_vtab; 5466 typedef struct sqlite3_index_info sqlite3_index_info; 5467 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5468 typedef struct sqlite3_module sqlite3_module; 5469 5470 /* 5471 ** CAPI3REF: Virtual Table Object 5472 ** KEYWORDS: sqlite3_module {virtual table module} 5473 ** 5474 ** This structure, sometimes called a "virtual table module", 5475 ** defines the implementation of a [virtual tables]. 5476 ** This structure consists mostly of methods for the module. 5477 ** 5478 ** ^A virtual table module is created by filling in a persistent 5479 ** instance of this structure and passing a pointer to that instance 5480 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5481 ** ^The registration remains valid until it is replaced by a different 5482 ** module or until the [database connection] closes. The content 5483 ** of this structure must not change while it is registered with 5484 ** any database connection. 5485 */ 5486 struct sqlite3_module { 5487 int iVersion; 5488 int (*xCreate)(sqlite3*, void *pAux, 5489 int argc, const char *const*argv, 5490 sqlite3_vtab **ppVTab, char**); 5491 int (*xConnect)(sqlite3*, void *pAux, 5492 int argc, const char *const*argv, 5493 sqlite3_vtab **ppVTab, char**); 5494 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5495 int (*xDisconnect)(sqlite3_vtab *pVTab); 5496 int (*xDestroy)(sqlite3_vtab *pVTab); 5497 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5498 int (*xClose)(sqlite3_vtab_cursor*); 5499 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5500 int argc, sqlite3_value **argv); 5501 int (*xNext)(sqlite3_vtab_cursor*); 5502 int (*xEof)(sqlite3_vtab_cursor*); 5503 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5504 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5505 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5506 int (*xBegin)(sqlite3_vtab *pVTab); 5507 int (*xSync)(sqlite3_vtab *pVTab); 5508 int (*xCommit)(sqlite3_vtab *pVTab); 5509 int (*xRollback)(sqlite3_vtab *pVTab); 5510 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5511 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5512 void **ppArg); 5513 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5514 /* The methods above are in version 1 of the sqlite_module object. Those 5515 ** below are for version 2 and greater. */ 5516 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5517 int (*xRelease)(sqlite3_vtab *pVTab, int); 5518 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5519 }; 5520 5521 /* 5522 ** CAPI3REF: Virtual Table Indexing Information 5523 ** KEYWORDS: sqlite3_index_info 5524 ** 5525 ** The sqlite3_index_info structure and its substructures is used as part 5526 ** of the [virtual table] interface to 5527 ** pass information into and receive the reply from the [xBestIndex] 5528 ** method of a [virtual table module]. The fields under **Inputs** are the 5529 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5530 ** results into the **Outputs** fields. 5531 ** 5532 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5533 ** 5534 ** <blockquote>column OP expr</blockquote> 5535 ** 5536 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5537 ** stored in aConstraint[].op using one of the 5538 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5539 ** ^(The index of the column is stored in 5540 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5541 ** expr on the right-hand side can be evaluated (and thus the constraint 5542 ** is usable) and false if it cannot.)^ 5543 ** 5544 ** ^The optimizer automatically inverts terms of the form "expr OP column" 5545 ** and makes other simplifications to the WHERE clause in an attempt to 5546 ** get as many WHERE clause terms into the form shown above as possible. 5547 ** ^The aConstraint[] array only reports WHERE clause terms that are 5548 ** relevant to the particular virtual table being queried. 5549 ** 5550 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5551 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5552 ** 5553 ** The [xBestIndex] method must fill aConstraintUsage[] with information 5554 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5555 ** the right-hand side of the corresponding aConstraint[] is evaluated 5556 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5557 ** is true, then the constraint is assumed to be fully handled by the 5558 ** virtual table and is not checked again by SQLite.)^ 5559 ** 5560 ** ^The idxNum and idxPtr values are recorded and passed into the 5561 ** [xFilter] method. 5562 ** ^[sqlite3_free()] is used to free idxPtr if and only if 5563 ** needToFreeIdxPtr is true. 5564 ** 5565 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5566 ** the correct order to satisfy the ORDER BY clause so that no separate 5567 ** sorting step is required. 5568 ** 5569 ** ^The estimatedCost value is an estimate of the cost of a particular 5570 ** strategy. A cost of N indicates that the cost of the strategy is similar 5571 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 5572 ** indicates that the expense of the operation is similar to that of a 5573 ** binary search on a unique indexed field of an SQLite table with N rows. 5574 ** 5575 ** ^The estimatedRows value is an estimate of the number of rows that 5576 ** will be returned by the strategy. 5577 ** 5578 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5579 ** structure for SQLite version 3.8.2. If a virtual table extension is 5580 ** used with an SQLite version earlier than 3.8.2, the results of attempting 5581 ** to read or write the estimatedRows field are undefined (but are likely 5582 ** to included crashing the application). The estimatedRows field should 5583 ** therefore only be used if [sqlite3_libversion_number()] returns a 5584 ** value greater than or equal to 3008002. 5585 */ 5586 struct sqlite3_index_info { 5587 /* Inputs */ 5588 int nConstraint; /* Number of entries in aConstraint */ 5589 struct sqlite3_index_constraint { 5590 int iColumn; /* Column on left-hand side of constraint */ 5591 unsigned char op; /* Constraint operator */ 5592 unsigned char usable; /* True if this constraint is usable */ 5593 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5594 } *aConstraint; /* Table of WHERE clause constraints */ 5595 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5596 struct sqlite3_index_orderby { 5597 int iColumn; /* Column number */ 5598 unsigned char desc; /* True for DESC. False for ASC. */ 5599 } *aOrderBy; /* The ORDER BY clause */ 5600 /* Outputs */ 5601 struct sqlite3_index_constraint_usage { 5602 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5603 unsigned char omit; /* Do not code a test for this constraint */ 5604 } *aConstraintUsage; 5605 int idxNum; /* Number used to identify the index */ 5606 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5607 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5608 int orderByConsumed; /* True if output is already ordered */ 5609 double estimatedCost; /* Estimated cost of using this index */ 5610 /* Fields below are only available in SQLite 3.8.2 and later */ 5611 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5612 }; 5613 5614 /* 5615 ** CAPI3REF: Virtual Table Constraint Operator Codes 5616 ** 5617 ** These macros defined the allowed values for the 5618 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 5619 ** an operator that is part of a constraint term in the wHERE clause of 5620 ** a query that uses a [virtual table]. 5621 */ 5622 #define SQLITE_INDEX_CONSTRAINT_EQ 2 5623 #define SQLITE_INDEX_CONSTRAINT_GT 4 5624 #define SQLITE_INDEX_CONSTRAINT_LE 8 5625 #define SQLITE_INDEX_CONSTRAINT_LT 16 5626 #define SQLITE_INDEX_CONSTRAINT_GE 32 5627 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 5628 5629 /* 5630 ** CAPI3REF: Register A Virtual Table Implementation 5631 ** METHOD: sqlite3 5632 ** 5633 ** ^These routines are used to register a new [virtual table module] name. 5634 ** ^Module names must be registered before 5635 ** creating a new [virtual table] using the module and before using a 5636 ** preexisting [virtual table] for the module. 5637 ** 5638 ** ^The module name is registered on the [database connection] specified 5639 ** by the first parameter. ^The name of the module is given by the 5640 ** second parameter. ^The third parameter is a pointer to 5641 ** the implementation of the [virtual table module]. ^The fourth 5642 ** parameter is an arbitrary client data pointer that is passed through 5643 ** into the [xCreate] and [xConnect] methods of the virtual table module 5644 ** when a new virtual table is be being created or reinitialized. 5645 ** 5646 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5647 ** is a pointer to a destructor for the pClientData. ^SQLite will 5648 ** invoke the destructor function (if it is not NULL) when SQLite 5649 ** no longer needs the pClientData pointer. ^The destructor will also 5650 ** be invoked if the call to sqlite3_create_module_v2() fails. 5651 ** ^The sqlite3_create_module() 5652 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 5653 ** destructor. 5654 */ 5655 SQLITE_API int SQLITE_STDCALL sqlite3_create_module( 5656 sqlite3 *db, /* SQLite connection to register module with */ 5657 const char *zName, /* Name of the module */ 5658 const sqlite3_module *p, /* Methods for the module */ 5659 void *pClientData /* Client data for xCreate/xConnect */ 5660 ); 5661 SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2( 5662 sqlite3 *db, /* SQLite connection to register module with */ 5663 const char *zName, /* Name of the module */ 5664 const sqlite3_module *p, /* Methods for the module */ 5665 void *pClientData, /* Client data for xCreate/xConnect */ 5666 void(*xDestroy)(void*) /* Module destructor function */ 5667 ); 5668 5669 /* 5670 ** CAPI3REF: Virtual Table Instance Object 5671 ** KEYWORDS: sqlite3_vtab 5672 ** 5673 ** Every [virtual table module] implementation uses a subclass 5674 ** of this object to describe a particular instance 5675 ** of the [virtual table]. Each subclass will 5676 ** be tailored to the specific needs of the module implementation. 5677 ** The purpose of this superclass is to define certain fields that are 5678 ** common to all module implementations. 5679 ** 5680 ** ^Virtual tables methods can set an error message by assigning a 5681 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5682 ** take care that any prior string is freed by a call to [sqlite3_free()] 5683 ** prior to assigning a new string to zErrMsg. ^After the error message 5684 ** is delivered up to the client application, the string will be automatically 5685 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5686 */ 5687 struct sqlite3_vtab { 5688 const sqlite3_module *pModule; /* The module for this virtual table */ 5689 int nRef; /* Number of open cursors */ 5690 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5691 /* Virtual table implementations will typically add additional fields */ 5692 }; 5693 5694 /* 5695 ** CAPI3REF: Virtual Table Cursor Object 5696 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5697 ** 5698 ** Every [virtual table module] implementation uses a subclass of the 5699 ** following structure to describe cursors that point into the 5700 ** [virtual table] and are used 5701 ** to loop through the virtual table. Cursors are created using the 5702 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5703 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5704 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5705 ** of the module. Each module implementation will define 5706 ** the content of a cursor structure to suit its own needs. 5707 ** 5708 ** This superclass exists in order to define fields of the cursor that 5709 ** are common to all implementations. 5710 */ 5711 struct sqlite3_vtab_cursor { 5712 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5713 /* Virtual table implementations will typically add additional fields */ 5714 }; 5715 5716 /* 5717 ** CAPI3REF: Declare The Schema Of A Virtual Table 5718 ** 5719 ** ^The [xCreate] and [xConnect] methods of a 5720 ** [virtual table module] call this interface 5721 ** to declare the format (the names and datatypes of the columns) of 5722 ** the virtual tables they implement. 5723 */ 5724 SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5725 5726 /* 5727 ** CAPI3REF: Overload A Function For A Virtual Table 5728 ** METHOD: sqlite3 5729 ** 5730 ** ^(Virtual tables can provide alternative implementations of functions 5731 ** using the [xFindFunction] method of the [virtual table module]. 5732 ** But global versions of those functions 5733 ** must exist in order to be overloaded.)^ 5734 ** 5735 ** ^(This API makes sure a global version of a function with a particular 5736 ** name and number of parameters exists. If no such function exists 5737 ** before this API is called, a new function is created.)^ ^The implementation 5738 ** of the new function always causes an exception to be thrown. So 5739 ** the new function is not good for anything by itself. Its only 5740 ** purpose is to be a placeholder function that can be overloaded 5741 ** by a [virtual table]. 5742 */ 5743 SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5744 5745 /* 5746 ** The interface to the virtual-table mechanism defined above (back up 5747 ** to a comment remarkably similar to this one) is currently considered 5748 ** to be experimental. The interface might change in incompatible ways. 5749 ** If this is a problem for you, do not use the interface at this time. 5750 ** 5751 ** When the virtual-table mechanism stabilizes, we will declare the 5752 ** interface fixed, support it indefinitely, and remove this comment. 5753 */ 5754 5755 /* 5756 ** CAPI3REF: A Handle To An Open BLOB 5757 ** KEYWORDS: {BLOB handle} {BLOB handles} 5758 ** 5759 ** An instance of this object represents an open BLOB on which 5760 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5761 ** ^Objects of this type are created by [sqlite3_blob_open()] 5762 ** and destroyed by [sqlite3_blob_close()]. 5763 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5764 ** can be used to read or write small subsections of the BLOB. 5765 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5766 */ 5767 typedef struct sqlite3_blob sqlite3_blob; 5768 5769 /* 5770 ** CAPI3REF: Open A BLOB For Incremental I/O 5771 ** METHOD: sqlite3 5772 ** CONSTRUCTOR: sqlite3_blob 5773 ** 5774 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5775 ** in row iRow, column zColumn, table zTable in database zDb; 5776 ** in other words, the same BLOB that would be selected by: 5777 ** 5778 ** <pre> 5779 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5780 ** </pre>)^ 5781 ** 5782 ** ^(Parameter zDb is not the filename that contains the database, but 5783 ** rather the symbolic name of the database. For attached databases, this is 5784 ** the name that appears after the AS keyword in the [ATTACH] statement. 5785 ** For the main database file, the database name is "main". For TEMP 5786 ** tables, the database name is "temp".)^ 5787 ** 5788 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 5789 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 5790 ** read-only access. 5791 ** 5792 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 5793 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 5794 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 5795 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 5796 ** on *ppBlob after this function it returns. 5797 ** 5798 ** This function fails with SQLITE_ERROR if any of the following are true: 5799 ** <ul> 5800 ** <li> ^(Database zDb does not exist)^, 5801 ** <li> ^(Table zTable does not exist within database zDb)^, 5802 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 5803 ** <li> ^(Column zColumn does not exist)^, 5804 ** <li> ^(Row iRow is not present in the table)^, 5805 ** <li> ^(The specified column of row iRow contains a value that is not 5806 ** a TEXT or BLOB value)^, 5807 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 5808 ** constraint and the blob is being opened for read/write access)^, 5809 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 5810 ** column zColumn is part of a [child key] definition and the blob is 5811 ** being opened for read/write access)^. 5812 ** </ul> 5813 ** 5814 ** ^Unless it returns SQLITE_MISUSE, this function sets the 5815 ** [database connection] error code and message accessible via 5816 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5817 ** 5818 ** 5819 ** ^(If the row that a BLOB handle points to is modified by an 5820 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5821 ** then the BLOB handle is marked as "expired". 5822 ** This is true if any column of the row is changed, even a column 5823 ** other than the one the BLOB handle is open on.)^ 5824 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5825 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5826 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 5827 ** rolled back by the expiration of the BLOB. Such changes will eventually 5828 ** commit if the transaction continues to completion.)^ 5829 ** 5830 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5831 ** the opened blob. ^The size of a blob may not be changed by this 5832 ** interface. Use the [UPDATE] SQL command to change the size of a 5833 ** blob. 5834 ** 5835 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5836 ** and the built-in [zeroblob] SQL function may be used to create a 5837 ** zero-filled blob to read or write using the incremental-blob interface. 5838 ** 5839 ** To avoid a resource leak, every open [BLOB handle] should eventually 5840 ** be released by a call to [sqlite3_blob_close()]. 5841 */ 5842 SQLITE_API int SQLITE_STDCALL sqlite3_blob_open( 5843 sqlite3*, 5844 const char *zDb, 5845 const char *zTable, 5846 const char *zColumn, 5847 sqlite3_int64 iRow, 5848 int flags, 5849 sqlite3_blob **ppBlob 5850 ); 5851 5852 /* 5853 ** CAPI3REF: Move a BLOB Handle to a New Row 5854 ** METHOD: sqlite3_blob 5855 ** 5856 ** ^This function is used to move an existing blob handle so that it points 5857 ** to a different row of the same database table. ^The new row is identified 5858 ** by the rowid value passed as the second argument. Only the row can be 5859 ** changed. ^The database, table and column on which the blob handle is open 5860 ** remain the same. Moving an existing blob handle to a new row can be 5861 ** faster than closing the existing handle and opening a new one. 5862 ** 5863 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5864 ** it must exist and there must be either a blob or text value stored in 5865 ** the nominated column.)^ ^If the new row is not present in the table, or if 5866 ** it does not contain a blob or text value, or if another error occurs, an 5867 ** SQLite error code is returned and the blob handle is considered aborted. 5868 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5869 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5870 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5871 ** always returns zero. 5872 ** 5873 ** ^This function sets the database handle error code and message. 5874 */ 5875 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5876 5877 /* 5878 ** CAPI3REF: Close A BLOB Handle 5879 ** DESTRUCTOR: sqlite3_blob 5880 ** 5881 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 5882 ** unconditionally. Even if this routine returns an error code, the 5883 ** handle is still closed.)^ 5884 ** 5885 ** ^If the blob handle being closed was opened for read-write access, and if 5886 ** the database is in auto-commit mode and there are no other open read-write 5887 ** blob handles or active write statements, the current transaction is 5888 ** committed. ^If an error occurs while committing the transaction, an error 5889 ** code is returned and the transaction rolled back. 5890 ** 5891 ** Calling this function with an argument that is not a NULL pointer or an 5892 ** open blob handle results in undefined behaviour. ^Calling this routine 5893 ** with a null pointer (such as would be returned by a failed call to 5894 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 5895 ** is passed a valid open blob handle, the values returned by the 5896 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 5897 */ 5898 SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *); 5899 5900 /* 5901 ** CAPI3REF: Return The Size Of An Open BLOB 5902 ** METHOD: sqlite3_blob 5903 ** 5904 ** ^Returns the size in bytes of the BLOB accessible via the 5905 ** successfully opened [BLOB handle] in its only argument. ^The 5906 ** incremental blob I/O routines can only read or overwriting existing 5907 ** blob content; they cannot change the size of a blob. 5908 ** 5909 ** This routine only works on a [BLOB handle] which has been created 5910 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5911 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5912 ** to this routine results in undefined and probably undesirable behavior. 5913 */ 5914 SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *); 5915 5916 /* 5917 ** CAPI3REF: Read Data From A BLOB Incrementally 5918 ** METHOD: sqlite3_blob 5919 ** 5920 ** ^(This function is used to read data from an open [BLOB handle] into a 5921 ** caller-supplied buffer. N bytes of data are copied into buffer Z 5922 ** from the open BLOB, starting at offset iOffset.)^ 5923 ** 5924 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 5925 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5926 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 5927 ** ^The size of the blob (and hence the maximum value of N+iOffset) 5928 ** can be determined using the [sqlite3_blob_bytes()] interface. 5929 ** 5930 ** ^An attempt to read from an expired [BLOB handle] fails with an 5931 ** error code of [SQLITE_ABORT]. 5932 ** 5933 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5934 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 5935 ** 5936 ** This routine only works on a [BLOB handle] which has been created 5937 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5938 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5939 ** to this routine results in undefined and probably undesirable behavior. 5940 ** 5941 ** See also: [sqlite3_blob_write()]. 5942 */ 5943 SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5944 5945 /* 5946 ** CAPI3REF: Write Data Into A BLOB Incrementally 5947 ** METHOD: sqlite3_blob 5948 ** 5949 ** ^(This function is used to write data into an open [BLOB handle] from a 5950 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 5951 ** into the open BLOB, starting at offset iOffset.)^ 5952 ** 5953 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5954 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 5955 ** ^Unless SQLITE_MISUSE is returned, this function sets the 5956 ** [database connection] error code and message accessible via 5957 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 5958 ** 5959 ** ^If the [BLOB handle] passed as the first argument was not opened for 5960 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5961 ** this function returns [SQLITE_READONLY]. 5962 ** 5963 ** This function may only modify the contents of the BLOB; it is 5964 ** not possible to increase the size of a BLOB using this API. 5965 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 5966 ** [SQLITE_ERROR] is returned and no data is written. The size of the 5967 ** BLOB (and hence the maximum value of N+iOffset) can be determined 5968 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 5969 ** than zero [SQLITE_ERROR] is returned and no data is written. 5970 ** 5971 ** ^An attempt to write to an expired [BLOB handle] fails with an 5972 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5973 ** before the [BLOB handle] expired are not rolled back by the 5974 ** expiration of the handle, though of course those changes might 5975 ** have been overwritten by the statement that expired the BLOB handle 5976 ** or by other independent statements. 5977 ** 5978 ** This routine only works on a [BLOB handle] which has been created 5979 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5980 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5981 ** to this routine results in undefined and probably undesirable behavior. 5982 ** 5983 ** See also: [sqlite3_blob_read()]. 5984 */ 5985 SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5986 5987 /* 5988 ** CAPI3REF: Virtual File System Objects 5989 ** 5990 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5991 ** that SQLite uses to interact 5992 ** with the underlying operating system. Most SQLite builds come with a 5993 ** single default VFS that is appropriate for the host computer. 5994 ** New VFSes can be registered and existing VFSes can be unregistered. 5995 ** The following interfaces are provided. 5996 ** 5997 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5998 ** ^Names are case sensitive. 5999 ** ^Names are zero-terminated UTF-8 strings. 6000 ** ^If there is no match, a NULL pointer is returned. 6001 ** ^If zVfsName is NULL then the default VFS is returned. 6002 ** 6003 ** ^New VFSes are registered with sqlite3_vfs_register(). 6004 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6005 ** ^The same VFS can be registered multiple times without injury. 6006 ** ^To make an existing VFS into the default VFS, register it again 6007 ** with the makeDflt flag set. If two different VFSes with the 6008 ** same name are registered, the behavior is undefined. If a 6009 ** VFS is registered with a name that is NULL or an empty string, 6010 ** then the behavior is undefined. 6011 ** 6012 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6013 ** ^(If the default VFS is unregistered, another VFS is chosen as 6014 ** the default. The choice for the new VFS is arbitrary.)^ 6015 */ 6016 SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName); 6017 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6018 SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*); 6019 6020 /* 6021 ** CAPI3REF: Mutexes 6022 ** 6023 ** The SQLite core uses these routines for thread 6024 ** synchronization. Though they are intended for internal 6025 ** use by SQLite, code that links against SQLite is 6026 ** permitted to use any of these routines. 6027 ** 6028 ** The SQLite source code contains multiple implementations 6029 ** of these mutex routines. An appropriate implementation 6030 ** is selected automatically at compile-time. The following 6031 ** implementations are available in the SQLite core: 6032 ** 6033 ** <ul> 6034 ** <li> SQLITE_MUTEX_PTHREADS 6035 ** <li> SQLITE_MUTEX_W32 6036 ** <li> SQLITE_MUTEX_NOOP 6037 ** </ul> 6038 ** 6039 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6040 ** that does no real locking and is appropriate for use in 6041 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6042 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6043 ** and Windows. 6044 ** 6045 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6046 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6047 ** implementation is included with the library. In this case the 6048 ** application must supply a custom mutex implementation using the 6049 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6050 ** before calling sqlite3_initialize() or any other public sqlite3_ 6051 ** function that calls sqlite3_initialize(). 6052 ** 6053 ** ^The sqlite3_mutex_alloc() routine allocates a new 6054 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6055 ** routine returns NULL if it is unable to allocate the requested 6056 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6057 ** integer constants: 6058 ** 6059 ** <ul> 6060 ** <li> SQLITE_MUTEX_FAST 6061 ** <li> SQLITE_MUTEX_RECURSIVE 6062 ** <li> SQLITE_MUTEX_STATIC_MASTER 6063 ** <li> SQLITE_MUTEX_STATIC_MEM 6064 ** <li> SQLITE_MUTEX_STATIC_OPEN 6065 ** <li> SQLITE_MUTEX_STATIC_PRNG 6066 ** <li> SQLITE_MUTEX_STATIC_LRU 6067 ** <li> SQLITE_MUTEX_STATIC_PMEM 6068 ** <li> SQLITE_MUTEX_STATIC_APP1 6069 ** <li> SQLITE_MUTEX_STATIC_APP2 6070 ** <li> SQLITE_MUTEX_STATIC_APP3 6071 ** </ul> 6072 ** 6073 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6074 ** cause sqlite3_mutex_alloc() to create 6075 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6076 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6077 ** The mutex implementation does not need to make a distinction 6078 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6079 ** not want to. SQLite will only request a recursive mutex in 6080 ** cases where it really needs one. If a faster non-recursive mutex 6081 ** implementation is available on the host platform, the mutex subsystem 6082 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6083 ** 6084 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6085 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6086 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6087 ** used by the current version of SQLite. Future versions of SQLite 6088 ** may add additional static mutexes. Static mutexes are for internal 6089 ** use by SQLite only. Applications that use SQLite mutexes should 6090 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6091 ** SQLITE_MUTEX_RECURSIVE. 6092 ** 6093 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6094 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6095 ** returns a different mutex on every call. ^For the static 6096 ** mutex types, the same mutex is returned on every call that has 6097 ** the same type number. 6098 ** 6099 ** ^The sqlite3_mutex_free() routine deallocates a previously 6100 ** allocated dynamic mutex. Attempting to deallocate a static 6101 ** mutex results in undefined behavior. 6102 ** 6103 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6104 ** to enter a mutex. ^If another thread is already within the mutex, 6105 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6106 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6107 ** upon successful entry. ^(Mutexes created using 6108 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6109 ** In such cases, the 6110 ** mutex must be exited an equal number of times before another thread 6111 ** can enter.)^ If the same thread tries to enter any mutex other 6112 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6113 ** 6114 ** ^(Some systems (for example, Windows 95) do not support the operation 6115 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6116 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6117 ** sqlite3_mutex_try() as an optimization so this is acceptable 6118 ** behavior.)^ 6119 ** 6120 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6121 ** previously entered by the same thread. The behavior 6122 ** is undefined if the mutex is not currently entered by the 6123 ** calling thread or is not currently allocated. 6124 ** 6125 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6126 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6127 ** behave as no-ops. 6128 ** 6129 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6130 */ 6131 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int); 6132 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*); 6133 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*); 6134 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*); 6135 SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*); 6136 6137 /* 6138 ** CAPI3REF: Mutex Methods Object 6139 ** 6140 ** An instance of this structure defines the low-level routines 6141 ** used to allocate and use mutexes. 6142 ** 6143 ** Usually, the default mutex implementations provided by SQLite are 6144 ** sufficient, however the application has the option of substituting a custom 6145 ** implementation for specialized deployments or systems for which SQLite 6146 ** does not provide a suitable implementation. In this case, the application 6147 ** creates and populates an instance of this structure to pass 6148 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6149 ** Additionally, an instance of this structure can be used as an 6150 ** output variable when querying the system for the current mutex 6151 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6152 ** 6153 ** ^The xMutexInit method defined by this structure is invoked as 6154 ** part of system initialization by the sqlite3_initialize() function. 6155 ** ^The xMutexInit routine is called by SQLite exactly once for each 6156 ** effective call to [sqlite3_initialize()]. 6157 ** 6158 ** ^The xMutexEnd method defined by this structure is invoked as 6159 ** part of system shutdown by the sqlite3_shutdown() function. The 6160 ** implementation of this method is expected to release all outstanding 6161 ** resources obtained by the mutex methods implementation, especially 6162 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6163 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6164 ** 6165 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6166 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6167 ** xMutexNotheld) implement the following interfaces (respectively): 6168 ** 6169 ** <ul> 6170 ** <li> [sqlite3_mutex_alloc()] </li> 6171 ** <li> [sqlite3_mutex_free()] </li> 6172 ** <li> [sqlite3_mutex_enter()] </li> 6173 ** <li> [sqlite3_mutex_try()] </li> 6174 ** <li> [sqlite3_mutex_leave()] </li> 6175 ** <li> [sqlite3_mutex_held()] </li> 6176 ** <li> [sqlite3_mutex_notheld()] </li> 6177 ** </ul>)^ 6178 ** 6179 ** The only difference is that the public sqlite3_XXX functions enumerated 6180 ** above silently ignore any invocations that pass a NULL pointer instead 6181 ** of a valid mutex handle. The implementations of the methods defined 6182 ** by this structure are not required to handle this case, the results 6183 ** of passing a NULL pointer instead of a valid mutex handle are undefined 6184 ** (i.e. it is acceptable to provide an implementation that segfaults if 6185 ** it is passed a NULL pointer). 6186 ** 6187 ** The xMutexInit() method must be threadsafe. It must be harmless to 6188 ** invoke xMutexInit() multiple times within the same process and without 6189 ** intervening calls to xMutexEnd(). Second and subsequent calls to 6190 ** xMutexInit() must be no-ops. 6191 ** 6192 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6193 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6194 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6195 ** memory allocation for a fast or recursive mutex. 6196 ** 6197 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6198 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6199 ** If xMutexInit fails in any way, it is expected to clean up after itself 6200 ** prior to returning. 6201 */ 6202 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6203 struct sqlite3_mutex_methods { 6204 int (*xMutexInit)(void); 6205 int (*xMutexEnd)(void); 6206 sqlite3_mutex *(*xMutexAlloc)(int); 6207 void (*xMutexFree)(sqlite3_mutex *); 6208 void (*xMutexEnter)(sqlite3_mutex *); 6209 int (*xMutexTry)(sqlite3_mutex *); 6210 void (*xMutexLeave)(sqlite3_mutex *); 6211 int (*xMutexHeld)(sqlite3_mutex *); 6212 int (*xMutexNotheld)(sqlite3_mutex *); 6213 }; 6214 6215 /* 6216 ** CAPI3REF: Mutex Verification Routines 6217 ** 6218 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6219 ** are intended for use inside assert() statements. The SQLite core 6220 ** never uses these routines except inside an assert() and applications 6221 ** are advised to follow the lead of the core. The SQLite core only 6222 ** provides implementations for these routines when it is compiled 6223 ** with the SQLITE_DEBUG flag. External mutex implementations 6224 ** are only required to provide these routines if SQLITE_DEBUG is 6225 ** defined and if NDEBUG is not defined. 6226 ** 6227 ** These routines should return true if the mutex in their argument 6228 ** is held or not held, respectively, by the calling thread. 6229 ** 6230 ** The implementation is not required to provide versions of these 6231 ** routines that actually work. If the implementation does not provide working 6232 ** versions of these routines, it should at least provide stubs that always 6233 ** return true so that one does not get spurious assertion failures. 6234 ** 6235 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6236 ** the routine should return 1. This seems counter-intuitive since 6237 ** clearly the mutex cannot be held if it does not exist. But 6238 ** the reason the mutex does not exist is because the build is not 6239 ** using mutexes. And we do not want the assert() containing the 6240 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6241 ** the appropriate thing to do. The sqlite3_mutex_notheld() 6242 ** interface should also return 1 when given a NULL pointer. 6243 */ 6244 #ifndef NDEBUG 6245 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*); 6246 SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*); 6247 #endif 6248 6249 /* 6250 ** CAPI3REF: Mutex Types 6251 ** 6252 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6253 ** which is one of these integer constants. 6254 ** 6255 ** The set of static mutexes may change from one SQLite release to the 6256 ** next. Applications that override the built-in mutex logic must be 6257 ** prepared to accommodate additional static mutexes. 6258 */ 6259 #define SQLITE_MUTEX_FAST 0 6260 #define SQLITE_MUTEX_RECURSIVE 1 6261 #define SQLITE_MUTEX_STATIC_MASTER 2 6262 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6263 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6264 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6265 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6266 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6267 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6268 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6269 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6270 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6271 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6272 6273 /* 6274 ** CAPI3REF: Retrieve the mutex for a database connection 6275 ** METHOD: sqlite3 6276 ** 6277 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6278 ** serializes access to the [database connection] given in the argument 6279 ** when the [threading mode] is Serialized. 6280 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6281 ** routine returns a NULL pointer. 6282 */ 6283 SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*); 6284 6285 /* 6286 ** CAPI3REF: Low-Level Control Of Database Files 6287 ** METHOD: sqlite3 6288 ** 6289 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6290 ** xFileControl method for the [sqlite3_io_methods] object associated 6291 ** with a particular database identified by the second argument. ^The 6292 ** name of the database is "main" for the main database or "temp" for the 6293 ** TEMP database, or the name that appears after the AS keyword for 6294 ** databases that are added using the [ATTACH] SQL command. 6295 ** ^A NULL pointer can be used in place of "main" to refer to the 6296 ** main database file. 6297 ** ^The third and fourth parameters to this routine 6298 ** are passed directly through to the second and third parameters of 6299 ** the xFileControl method. ^The return value of the xFileControl 6300 ** method becomes the return value of this routine. 6301 ** 6302 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6303 ** a pointer to the underlying [sqlite3_file] object to be written into 6304 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6305 ** case is a short-circuit path which does not actually invoke the 6306 ** underlying sqlite3_io_methods.xFileControl method. 6307 ** 6308 ** ^If the second parameter (zDbName) does not match the name of any 6309 ** open database file, then SQLITE_ERROR is returned. ^This error 6310 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6311 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6312 ** also return SQLITE_ERROR. There is no way to distinguish between 6313 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6314 ** xFileControl method. 6315 ** 6316 ** See also: [SQLITE_FCNTL_LOCKSTATE] 6317 */ 6318 SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6319 6320 /* 6321 ** CAPI3REF: Testing Interface 6322 ** 6323 ** ^The sqlite3_test_control() interface is used to read out internal 6324 ** state of SQLite and to inject faults into SQLite for testing 6325 ** purposes. ^The first parameter is an operation code that determines 6326 ** the number, meaning, and operation of all subsequent parameters. 6327 ** 6328 ** This interface is not for use by applications. It exists solely 6329 ** for verifying the correct operation of the SQLite library. Depending 6330 ** on how the SQLite library is compiled, this interface might not exist. 6331 ** 6332 ** The details of the operation codes, their meanings, the parameters 6333 ** they take, and what they do are all subject to change without notice. 6334 ** Unlike most of the SQLite API, this function is not guaranteed to 6335 ** operate consistently from one release to the next. 6336 */ 6337 SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...); 6338 6339 /* 6340 ** CAPI3REF: Testing Interface Operation Codes 6341 ** 6342 ** These constants are the valid operation code parameters used 6343 ** as the first argument to [sqlite3_test_control()]. 6344 ** 6345 ** These parameters and their meanings are subject to change 6346 ** without notice. These values are for testing purposes only. 6347 ** Applications should not use any of these parameters or the 6348 ** [sqlite3_test_control()] interface. 6349 */ 6350 #define SQLITE_TESTCTRL_FIRST 5 6351 #define SQLITE_TESTCTRL_PRNG_SAVE 5 6352 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6353 #define SQLITE_TESTCTRL_PRNG_RESET 7 6354 #define SQLITE_TESTCTRL_BITVEC_TEST 8 6355 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6356 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6357 #define SQLITE_TESTCTRL_PENDING_BYTE 11 6358 #define SQLITE_TESTCTRL_ASSERT 12 6359 #define SQLITE_TESTCTRL_ALWAYS 13 6360 #define SQLITE_TESTCTRL_RESERVE 14 6361 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6362 #define SQLITE_TESTCTRL_ISKEYWORD 16 6363 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6364 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6365 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6366 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6367 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6368 #define SQLITE_TESTCTRL_BYTEORDER 22 6369 #define SQLITE_TESTCTRL_ISINIT 23 6370 #define SQLITE_TESTCTRL_SORTER_MMAP 24 6371 #define SQLITE_TESTCTRL_IMPOSTER 25 6372 #define SQLITE_TESTCTRL_LAST 25 6373 6374 /* 6375 ** CAPI3REF: SQLite Runtime Status 6376 ** 6377 ** ^These interfaces are used to retrieve runtime status information 6378 ** about the performance of SQLite, and optionally to reset various 6379 ** highwater marks. ^The first argument is an integer code for 6380 ** the specific parameter to measure. ^(Recognized integer codes 6381 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 6382 ** ^The current value of the parameter is returned into *pCurrent. 6383 ** ^The highest recorded value is returned in *pHighwater. ^If the 6384 ** resetFlag is true, then the highest record value is reset after 6385 ** *pHighwater is written. ^(Some parameters do not record the highest 6386 ** value. For those parameters 6387 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6388 ** ^(Other parameters record only the highwater mark and not the current 6389 ** value. For these latter parameters nothing is written into *pCurrent.)^ 6390 ** 6391 ** ^The sqlite3_status() and sqlite3_status64() routines return 6392 ** SQLITE_OK on success and a non-zero [error code] on failure. 6393 ** 6394 ** If either the current value or the highwater mark is too large to 6395 ** be represented by a 32-bit integer, then the values returned by 6396 ** sqlite3_status() are undefined. 6397 ** 6398 ** See also: [sqlite3_db_status()] 6399 */ 6400 SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6401 SQLITE_API int SQLITE_STDCALL sqlite3_status64( 6402 int op, 6403 sqlite3_int64 *pCurrent, 6404 sqlite3_int64 *pHighwater, 6405 int resetFlag 6406 ); 6407 6408 6409 /* 6410 ** CAPI3REF: Status Parameters 6411 ** KEYWORDS: {status parameters} 6412 ** 6413 ** These integer constants designate various run-time status parameters 6414 ** that can be returned by [sqlite3_status()]. 6415 ** 6416 ** <dl> 6417 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6418 ** <dd>This parameter is the current amount of memory checked out 6419 ** using [sqlite3_malloc()], either directly or indirectly. The 6420 ** figure includes calls made to [sqlite3_malloc()] by the application 6421 ** and internal memory usage by the SQLite library. Scratch memory 6422 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6423 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6424 ** this parameter. The amount returned is the sum of the allocation 6425 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6426 ** 6427 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6428 ** <dd>This parameter records the largest memory allocation request 6429 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6430 ** internal equivalents). Only the value returned in the 6431 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6432 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6433 ** 6434 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6435 ** <dd>This parameter records the number of separate memory allocations 6436 ** currently checked out.</dd>)^ 6437 ** 6438 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6439 ** <dd>This parameter returns the number of pages used out of the 6440 ** [pagecache memory allocator] that was configured using 6441 ** [SQLITE_CONFIG_PAGECACHE]. The 6442 ** value returned is in pages, not in bytes.</dd>)^ 6443 ** 6444 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6445 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6446 ** <dd>This parameter returns the number of bytes of page cache 6447 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6448 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6449 ** returned value includes allocations that overflowed because they 6450 ** where too large (they were larger than the "sz" parameter to 6451 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6452 ** no space was left in the page cache.</dd>)^ 6453 ** 6454 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6455 ** <dd>This parameter records the largest memory allocation request 6456 ** handed to [pagecache memory allocator]. Only the value returned in the 6457 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6458 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6459 ** 6460 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6461 ** <dd>This parameter returns the number of allocations used out of the 6462 ** [scratch memory allocator] configured using 6463 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6464 ** in bytes. Since a single thread may only have one scratch allocation 6465 ** outstanding at time, this parameter also reports the number of threads 6466 ** using scratch memory at the same time.</dd>)^ 6467 ** 6468 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6469 ** <dd>This parameter returns the number of bytes of scratch memory 6470 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6471 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6472 ** returned include overflows because the requested allocation was too 6473 ** larger (that is, because the requested allocation was larger than the 6474 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6475 ** slots were available. 6476 ** </dd>)^ 6477 ** 6478 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6479 ** <dd>This parameter records the largest memory allocation request 6480 ** handed to [scratch memory allocator]. Only the value returned in the 6481 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6482 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6483 ** 6484 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6485 ** <dd>This parameter records the deepest parser stack. It is only 6486 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6487 ** </dl> 6488 ** 6489 ** New status parameters may be added from time to time. 6490 */ 6491 #define SQLITE_STATUS_MEMORY_USED 0 6492 #define SQLITE_STATUS_PAGECACHE_USED 1 6493 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6494 #define SQLITE_STATUS_SCRATCH_USED 3 6495 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6496 #define SQLITE_STATUS_MALLOC_SIZE 5 6497 #define SQLITE_STATUS_PARSER_STACK 6 6498 #define SQLITE_STATUS_PAGECACHE_SIZE 7 6499 #define SQLITE_STATUS_SCRATCH_SIZE 8 6500 #define SQLITE_STATUS_MALLOC_COUNT 9 6501 6502 /* 6503 ** CAPI3REF: Database Connection Status 6504 ** METHOD: sqlite3 6505 ** 6506 ** ^This interface is used to retrieve runtime status information 6507 ** about a single [database connection]. ^The first argument is the 6508 ** database connection object to be interrogated. ^The second argument 6509 ** is an integer constant, taken from the set of 6510 ** [SQLITE_DBSTATUS options], that 6511 ** determines the parameter to interrogate. The set of 6512 ** [SQLITE_DBSTATUS options] is likely 6513 ** to grow in future releases of SQLite. 6514 ** 6515 ** ^The current value of the requested parameter is written into *pCur 6516 ** and the highest instantaneous value is written into *pHiwtr. ^If 6517 ** the resetFlg is true, then the highest instantaneous value is 6518 ** reset back down to the current value. 6519 ** 6520 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6521 ** non-zero [error code] on failure. 6522 ** 6523 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6524 */ 6525 SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6526 6527 /* 6528 ** CAPI3REF: Status Parameters for database connections 6529 ** KEYWORDS: {SQLITE_DBSTATUS options} 6530 ** 6531 ** These constants are the available integer "verbs" that can be passed as 6532 ** the second argument to the [sqlite3_db_status()] interface. 6533 ** 6534 ** New verbs may be added in future releases of SQLite. Existing verbs 6535 ** might be discontinued. Applications should check the return code from 6536 ** [sqlite3_db_status()] to make sure that the call worked. 6537 ** The [sqlite3_db_status()] interface will return a non-zero error code 6538 ** if a discontinued or unsupported verb is invoked. 6539 ** 6540 ** <dl> 6541 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6542 ** <dd>This parameter returns the number of lookaside memory slots currently 6543 ** checked out.</dd>)^ 6544 ** 6545 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6546 ** <dd>This parameter returns the number malloc attempts that were 6547 ** satisfied using lookaside memory. Only the high-water value is meaningful; 6548 ** the current value is always zero.)^ 6549 ** 6550 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6551 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6552 ** <dd>This parameter returns the number malloc attempts that might have 6553 ** been satisfied using lookaside memory but failed due to the amount of 6554 ** memory requested being larger than the lookaside slot size. 6555 ** Only the high-water value is meaningful; 6556 ** the current value is always zero.)^ 6557 ** 6558 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6559 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6560 ** <dd>This parameter returns the number malloc attempts that might have 6561 ** been satisfied using lookaside memory but failed due to all lookaside 6562 ** memory already being in use. 6563 ** Only the high-water value is meaningful; 6564 ** the current value is always zero.)^ 6565 ** 6566 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6567 ** <dd>This parameter returns the approximate number of bytes of heap 6568 ** memory used by all pager caches associated with the database connection.)^ 6569 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6570 ** 6571 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6572 ** <dd>This parameter returns the approximate number of bytes of heap 6573 ** memory used to store the schema for all databases associated 6574 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6575 ** ^The full amount of memory used by the schemas is reported, even if the 6576 ** schema memory is shared with other database connections due to 6577 ** [shared cache mode] being enabled. 6578 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6579 ** 6580 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6581 ** <dd>This parameter returns the approximate number of bytes of heap 6582 ** and lookaside memory used by all prepared statements associated with 6583 ** the database connection.)^ 6584 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6585 ** </dd> 6586 ** 6587 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6588 ** <dd>This parameter returns the number of pager cache hits that have 6589 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6590 ** is always 0. 6591 ** </dd> 6592 ** 6593 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6594 ** <dd>This parameter returns the number of pager cache misses that have 6595 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6596 ** is always 0. 6597 ** </dd> 6598 ** 6599 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6600 ** <dd>This parameter returns the number of dirty cache entries that have 6601 ** been written to disk. Specifically, the number of pages written to the 6602 ** wal file in wal mode databases, or the number of pages written to the 6603 ** database file in rollback mode databases. Any pages written as part of 6604 ** transaction rollback or database recovery operations are not included. 6605 ** If an IO or other error occurs while writing a page to disk, the effect 6606 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6607 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6608 ** </dd> 6609 ** 6610 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6611 ** <dd>This parameter returns zero for the current value if and only if 6612 ** all foreign key constraints (deferred or immediate) have been 6613 ** resolved.)^ ^The highwater mark is always 0. 6614 ** </dd> 6615 ** </dl> 6616 */ 6617 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6618 #define SQLITE_DBSTATUS_CACHE_USED 1 6619 #define SQLITE_DBSTATUS_SCHEMA_USED 2 6620 #define SQLITE_DBSTATUS_STMT_USED 3 6621 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6622 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6623 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6624 #define SQLITE_DBSTATUS_CACHE_HIT 7 6625 #define SQLITE_DBSTATUS_CACHE_MISS 8 6626 #define SQLITE_DBSTATUS_CACHE_WRITE 9 6627 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 6628 #define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6629 6630 6631 /* 6632 ** CAPI3REF: Prepared Statement Status 6633 ** METHOD: sqlite3_stmt 6634 ** 6635 ** ^(Each prepared statement maintains various 6636 ** [SQLITE_STMTSTATUS counters] that measure the number 6637 ** of times it has performed specific operations.)^ These counters can 6638 ** be used to monitor the performance characteristics of the prepared 6639 ** statements. For example, if the number of table steps greatly exceeds 6640 ** the number of table searches or result rows, that would tend to indicate 6641 ** that the prepared statement is using a full table scan rather than 6642 ** an index. 6643 ** 6644 ** ^(This interface is used to retrieve and reset counter values from 6645 ** a [prepared statement]. The first argument is the prepared statement 6646 ** object to be interrogated. The second argument 6647 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6648 ** to be interrogated.)^ 6649 ** ^The current value of the requested counter is returned. 6650 ** ^If the resetFlg is true, then the counter is reset to zero after this 6651 ** interface call returns. 6652 ** 6653 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6654 */ 6655 SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6656 6657 /* 6658 ** CAPI3REF: Status Parameters for prepared statements 6659 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6660 ** 6661 ** These preprocessor macros define integer codes that name counter 6662 ** values associated with the [sqlite3_stmt_status()] interface. 6663 ** The meanings of the various counters are as follows: 6664 ** 6665 ** <dl> 6666 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6667 ** <dd>^This is the number of times that SQLite has stepped forward in 6668 ** a table as part of a full table scan. Large numbers for this counter 6669 ** may indicate opportunities for performance improvement through 6670 ** careful use of indices.</dd> 6671 ** 6672 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6673 ** <dd>^This is the number of sort operations that have occurred. 6674 ** A non-zero value in this counter may indicate an opportunity to 6675 ** improvement performance through careful use of indices.</dd> 6676 ** 6677 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6678 ** <dd>^This is the number of rows inserted into transient indices that 6679 ** were created automatically in order to help joins run faster. 6680 ** A non-zero value in this counter may indicate an opportunity to 6681 ** improvement performance by adding permanent indices that do not 6682 ** need to be reinitialized each time the statement is run.</dd> 6683 ** 6684 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6685 ** <dd>^This is the number of virtual machine operations executed 6686 ** by the prepared statement if that number is less than or equal 6687 ** to 2147483647. The number of virtual machine operations can be 6688 ** used as a proxy for the total work done by the prepared statement. 6689 ** If the number of virtual machine operations exceeds 2147483647 6690 ** then the value returned by this statement status code is undefined. 6691 ** </dd> 6692 ** </dl> 6693 */ 6694 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6695 #define SQLITE_STMTSTATUS_SORT 2 6696 #define SQLITE_STMTSTATUS_AUTOINDEX 3 6697 #define SQLITE_STMTSTATUS_VM_STEP 4 6698 6699 /* 6700 ** CAPI3REF: Custom Page Cache Object 6701 ** 6702 ** The sqlite3_pcache type is opaque. It is implemented by 6703 ** the pluggable module. The SQLite core has no knowledge of 6704 ** its size or internal structure and never deals with the 6705 ** sqlite3_pcache object except by holding and passing pointers 6706 ** to the object. 6707 ** 6708 ** See [sqlite3_pcache_methods2] for additional information. 6709 */ 6710 typedef struct sqlite3_pcache sqlite3_pcache; 6711 6712 /* 6713 ** CAPI3REF: Custom Page Cache Object 6714 ** 6715 ** The sqlite3_pcache_page object represents a single page in the 6716 ** page cache. The page cache will allocate instances of this 6717 ** object. Various methods of the page cache use pointers to instances 6718 ** of this object as parameters or as their return value. 6719 ** 6720 ** See [sqlite3_pcache_methods2] for additional information. 6721 */ 6722 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6723 struct sqlite3_pcache_page { 6724 void *pBuf; /* The content of the page */ 6725 void *pExtra; /* Extra information associated with the page */ 6726 }; 6727 6728 /* 6729 ** CAPI3REF: Application Defined Page Cache. 6730 ** KEYWORDS: {page cache} 6731 ** 6732 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6733 ** register an alternative page cache implementation by passing in an 6734 ** instance of the sqlite3_pcache_methods2 structure.)^ 6735 ** In many applications, most of the heap memory allocated by 6736 ** SQLite is used for the page cache. 6737 ** By implementing a 6738 ** custom page cache using this API, an application can better control 6739 ** the amount of memory consumed by SQLite, the way in which 6740 ** that memory is allocated and released, and the policies used to 6741 ** determine exactly which parts of a database file are cached and for 6742 ** how long. 6743 ** 6744 ** The alternative page cache mechanism is an 6745 ** extreme measure that is only needed by the most demanding applications. 6746 ** The built-in page cache is recommended for most uses. 6747 ** 6748 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6749 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6750 ** the application may discard the parameter after the call to 6751 ** [sqlite3_config()] returns.)^ 6752 ** 6753 ** [[the xInit() page cache method]] 6754 ** ^(The xInit() method is called once for each effective 6755 ** call to [sqlite3_initialize()])^ 6756 ** (usually only once during the lifetime of the process). ^(The xInit() 6757 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6758 ** The intent of the xInit() method is to set up global data structures 6759 ** required by the custom page cache implementation. 6760 ** ^(If the xInit() method is NULL, then the 6761 ** built-in default page cache is used instead of the application defined 6762 ** page cache.)^ 6763 ** 6764 ** [[the xShutdown() page cache method]] 6765 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6766 ** It can be used to clean up 6767 ** any outstanding resources before process shutdown, if required. 6768 ** ^The xShutdown() method may be NULL. 6769 ** 6770 ** ^SQLite automatically serializes calls to the xInit method, 6771 ** so the xInit method need not be threadsafe. ^The 6772 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 6773 ** not need to be threadsafe either. All other methods must be threadsafe 6774 ** in multithreaded applications. 6775 ** 6776 ** ^SQLite will never invoke xInit() more than once without an intervening 6777 ** call to xShutdown(). 6778 ** 6779 ** [[the xCreate() page cache methods]] 6780 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 6781 ** SQLite will typically create one cache instance for each open database file, 6782 ** though this is not guaranteed. ^The 6783 ** first parameter, szPage, is the size in bytes of the pages that must 6784 ** be allocated by the cache. ^szPage will always a power of two. ^The 6785 ** second parameter szExtra is a number of bytes of extra storage 6786 ** associated with each page cache entry. ^The szExtra parameter will 6787 ** a number less than 250. SQLite will use the 6788 ** extra szExtra bytes on each page to store metadata about the underlying 6789 ** database page on disk. The value passed into szExtra depends 6790 ** on the SQLite version, the target platform, and how SQLite was compiled. 6791 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6792 ** created will be used to cache database pages of a file stored on disk, or 6793 ** false if it is used for an in-memory database. The cache implementation 6794 ** does not have to do anything special based with the value of bPurgeable; 6795 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6796 ** never invoke xUnpin() except to deliberately delete a page. 6797 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6798 ** false will always have the "discard" flag set to true. 6799 ** ^Hence, a cache created with bPurgeable false will 6800 ** never contain any unpinned pages. 6801 ** 6802 ** [[the xCachesize() page cache method]] 6803 ** ^(The xCachesize() method may be called at any time by SQLite to set the 6804 ** suggested maximum cache-size (number of pages stored by) the cache 6805 ** instance passed as the first argument. This is the value configured using 6806 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6807 ** parameter, the implementation is not required to do anything with this 6808 ** value; it is advisory only. 6809 ** 6810 ** [[the xPagecount() page cache methods]] 6811 ** The xPagecount() method must return the number of pages currently 6812 ** stored in the cache, both pinned and unpinned. 6813 ** 6814 ** [[the xFetch() page cache methods]] 6815 ** The xFetch() method locates a page in the cache and returns a pointer to 6816 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6817 ** The pBuf element of the returned sqlite3_pcache_page object will be a 6818 ** pointer to a buffer of szPage bytes used to store the content of a 6819 ** single database page. The pExtra element of sqlite3_pcache_page will be 6820 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 6821 ** for each entry in the page cache. 6822 ** 6823 ** The page to be fetched is determined by the key. ^The minimum key value 6824 ** is 1. After it has been retrieved using xFetch, the page is considered 6825 ** to be "pinned". 6826 ** 6827 ** If the requested page is already in the page cache, then the page cache 6828 ** implementation must return a pointer to the page buffer with its content 6829 ** intact. If the requested page is not already in the cache, then the 6830 ** cache implementation should use the value of the createFlag 6831 ** parameter to help it determined what action to take: 6832 ** 6833 ** <table border=1 width=85% align=center> 6834 ** <tr><th> createFlag <th> Behavior when page is not already in cache 6835 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6836 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6837 ** Otherwise return NULL. 6838 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6839 ** NULL if allocating a new page is effectively impossible. 6840 ** </table> 6841 ** 6842 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6843 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 6844 ** failed.)^ In between the to xFetch() calls, SQLite may 6845 ** attempt to unpin one or more cache pages by spilling the content of 6846 ** pinned pages to disk and synching the operating system disk cache. 6847 ** 6848 ** [[the xUnpin() page cache method]] 6849 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6850 ** as its second argument. If the third parameter, discard, is non-zero, 6851 ** then the page must be evicted from the cache. 6852 ** ^If the discard parameter is 6853 ** zero, then the page may be discarded or retained at the discretion of 6854 ** page cache implementation. ^The page cache implementation 6855 ** may choose to evict unpinned pages at any time. 6856 ** 6857 ** The cache must not perform any reference counting. A single 6858 ** call to xUnpin() unpins the page regardless of the number of prior calls 6859 ** to xFetch(). 6860 ** 6861 ** [[the xRekey() page cache methods]] 6862 ** The xRekey() method is used to change the key value associated with the 6863 ** page passed as the second argument. If the cache 6864 ** previously contains an entry associated with newKey, it must be 6865 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6866 ** to be pinned. 6867 ** 6868 ** When SQLite calls the xTruncate() method, the cache must discard all 6869 ** existing cache entries with page numbers (keys) greater than or equal 6870 ** to the value of the iLimit parameter passed to xTruncate(). If any 6871 ** of these pages are pinned, they are implicitly unpinned, meaning that 6872 ** they can be safely discarded. 6873 ** 6874 ** [[the xDestroy() page cache method]] 6875 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6876 ** All resources associated with the specified cache should be freed. ^After 6877 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6878 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6879 ** functions. 6880 ** 6881 ** [[the xShrink() page cache method]] 6882 ** ^SQLite invokes the xShrink() method when it wants the page cache to 6883 ** free up as much of heap memory as possible. The page cache implementation 6884 ** is not obligated to free any memory, but well-behaved implementations should 6885 ** do their best. 6886 */ 6887 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6888 struct sqlite3_pcache_methods2 { 6889 int iVersion; 6890 void *pArg; 6891 int (*xInit)(void*); 6892 void (*xShutdown)(void*); 6893 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6894 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6895 int (*xPagecount)(sqlite3_pcache*); 6896 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6897 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6898 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6899 unsigned oldKey, unsigned newKey); 6900 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6901 void (*xDestroy)(sqlite3_pcache*); 6902 void (*xShrink)(sqlite3_pcache*); 6903 }; 6904 6905 /* 6906 ** This is the obsolete pcache_methods object that has now been replaced 6907 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6908 ** retained in the header file for backwards compatibility only. 6909 */ 6910 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6911 struct sqlite3_pcache_methods { 6912 void *pArg; 6913 int (*xInit)(void*); 6914 void (*xShutdown)(void*); 6915 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6916 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6917 int (*xPagecount)(sqlite3_pcache*); 6918 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6919 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6920 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6921 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6922 void (*xDestroy)(sqlite3_pcache*); 6923 }; 6924 6925 6926 /* 6927 ** CAPI3REF: Online Backup Object 6928 ** 6929 ** The sqlite3_backup object records state information about an ongoing 6930 ** online backup operation. ^The sqlite3_backup object is created by 6931 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 6932 ** [sqlite3_backup_finish()]. 6933 ** 6934 ** See Also: [Using the SQLite Online Backup API] 6935 */ 6936 typedef struct sqlite3_backup sqlite3_backup; 6937 6938 /* 6939 ** CAPI3REF: Online Backup API. 6940 ** 6941 ** The backup API copies the content of one database into another. 6942 ** It is useful either for creating backups of databases or 6943 ** for copying in-memory databases to or from persistent files. 6944 ** 6945 ** See Also: [Using the SQLite Online Backup API] 6946 ** 6947 ** ^SQLite holds a write transaction open on the destination database file 6948 ** for the duration of the backup operation. 6949 ** ^The source database is read-locked only while it is being read; 6950 ** it is not locked continuously for the entire backup operation. 6951 ** ^Thus, the backup may be performed on a live source database without 6952 ** preventing other database connections from 6953 ** reading or writing to the source database while the backup is underway. 6954 ** 6955 ** ^(To perform a backup operation: 6956 ** <ol> 6957 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6958 ** backup, 6959 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6960 ** the data between the two databases, and finally 6961 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6962 ** associated with the backup operation. 6963 ** </ol>)^ 6964 ** There should be exactly one call to sqlite3_backup_finish() for each 6965 ** successful call to sqlite3_backup_init(). 6966 ** 6967 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6968 ** 6969 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6970 ** [database connection] associated with the destination database 6971 ** and the database name, respectively. 6972 ** ^The database name is "main" for the main database, "temp" for the 6973 ** temporary database, or the name specified after the AS keyword in 6974 ** an [ATTACH] statement for an attached database. 6975 ** ^The S and M arguments passed to 6976 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6977 ** and database name of the source database, respectively. 6978 ** ^The source and destination [database connections] (parameters S and D) 6979 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6980 ** an error. 6981 ** 6982 ** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if 6983 ** there is already a read or read-write transaction open on the 6984 ** destination database. 6985 ** 6986 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6987 ** returned and an error code and error message are stored in the 6988 ** destination [database connection] D. 6989 ** ^The error code and message for the failed call to sqlite3_backup_init() 6990 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6991 ** [sqlite3_errmsg16()] functions. 6992 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 6993 ** [sqlite3_backup] object. 6994 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6995 ** sqlite3_backup_finish() functions to perform the specified backup 6996 ** operation. 6997 ** 6998 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6999 ** 7000 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7001 ** the source and destination databases specified by [sqlite3_backup] object B. 7002 ** ^If N is negative, all remaining source pages are copied. 7003 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7004 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 7005 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7006 ** from source to destination, then it returns [SQLITE_DONE]. 7007 ** ^If an error occurs while running sqlite3_backup_step(B,N), 7008 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 7009 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7010 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7011 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7012 ** 7013 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7014 ** <ol> 7015 ** <li> the destination database was opened read-only, or 7016 ** <li> the destination database is using write-ahead-log journaling 7017 ** and the destination and source page sizes differ, or 7018 ** <li> the destination database is an in-memory database and the 7019 ** destination and source page sizes differ. 7020 ** </ol>)^ 7021 ** 7022 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7023 ** the [sqlite3_busy_handler | busy-handler function] 7024 ** is invoked (if one is specified). ^If the 7025 ** busy-handler returns non-zero before the lock is available, then 7026 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7027 ** sqlite3_backup_step() can be retried later. ^If the source 7028 ** [database connection] 7029 ** is being used to write to the source database when sqlite3_backup_step() 7030 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7031 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 7032 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7033 ** [SQLITE_READONLY] is returned, then 7034 ** there is no point in retrying the call to sqlite3_backup_step(). These 7035 ** errors are considered fatal.)^ The application must accept 7036 ** that the backup operation has failed and pass the backup operation handle 7037 ** to the sqlite3_backup_finish() to release associated resources. 7038 ** 7039 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7040 ** on the destination file. ^The exclusive lock is not released until either 7041 ** sqlite3_backup_finish() is called or the backup operation is complete 7042 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7043 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 7044 ** lasts for the duration of the sqlite3_backup_step() call. 7045 ** ^Because the source database is not locked between calls to 7046 ** sqlite3_backup_step(), the source database may be modified mid-way 7047 ** through the backup process. ^If the source database is modified by an 7048 ** external process or via a database connection other than the one being 7049 ** used by the backup operation, then the backup will be automatically 7050 ** restarted by the next call to sqlite3_backup_step(). ^If the source 7051 ** database is modified by the using the same database connection as is used 7052 ** by the backup operation, then the backup database is automatically 7053 ** updated at the same time. 7054 ** 7055 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7056 ** 7057 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7058 ** application wishes to abandon the backup operation, the application 7059 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7060 ** ^The sqlite3_backup_finish() interfaces releases all 7061 ** resources associated with the [sqlite3_backup] object. 7062 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7063 ** active write-transaction on the destination database is rolled back. 7064 ** The [sqlite3_backup] object is invalid 7065 ** and may not be used following a call to sqlite3_backup_finish(). 7066 ** 7067 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7068 ** sqlite3_backup_step() errors occurred, regardless or whether or not 7069 ** sqlite3_backup_step() completed. 7070 ** ^If an out-of-memory condition or IO error occurred during any prior 7071 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7072 ** sqlite3_backup_finish() returns the corresponding [error code]. 7073 ** 7074 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7075 ** is not a permanent error and does not affect the return value of 7076 ** sqlite3_backup_finish(). 7077 ** 7078 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7079 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7080 ** 7081 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7082 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7083 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7084 ** in the source database at the conclusion of the most recent 7085 ** sqlite3_backup_step(). 7086 ** ^(The values returned by these functions are only updated by 7087 ** sqlite3_backup_step(). If the source database is modified in a way that 7088 ** changes the size of the source database or the number of pages remaining, 7089 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7090 ** and sqlite3_backup_remaining() until after the next 7091 ** sqlite3_backup_step().)^ 7092 ** 7093 ** <b>Concurrent Usage of Database Handles</b> 7094 ** 7095 ** ^The source [database connection] may be used by the application for other 7096 ** purposes while a backup operation is underway or being initialized. 7097 ** ^If SQLite is compiled and configured to support threadsafe database 7098 ** connections, then the source database connection may be used concurrently 7099 ** from within other threads. 7100 ** 7101 ** However, the application must guarantee that the destination 7102 ** [database connection] is not passed to any other API (by any thread) after 7103 ** sqlite3_backup_init() is called and before the corresponding call to 7104 ** sqlite3_backup_finish(). SQLite does not currently check to see 7105 ** if the application incorrectly accesses the destination [database connection] 7106 ** and so no error code is reported, but the operations may malfunction 7107 ** nevertheless. Use of the destination database connection while a 7108 ** backup is in progress might also also cause a mutex deadlock. 7109 ** 7110 ** If running in [shared cache mode], the application must 7111 ** guarantee that the shared cache used by the destination database 7112 ** is not accessed while the backup is running. In practice this means 7113 ** that the application must guarantee that the disk file being 7114 ** backed up to is not accessed by any connection within the process, 7115 ** not just the specific connection that was passed to sqlite3_backup_init(). 7116 ** 7117 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7118 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7119 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7120 ** APIs are not strictly speaking threadsafe. If they are invoked at the 7121 ** same time as another thread is invoking sqlite3_backup_step() it is 7122 ** possible that they return invalid values. 7123 */ 7124 SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init( 7125 sqlite3 *pDest, /* Destination database handle */ 7126 const char *zDestName, /* Destination database name */ 7127 sqlite3 *pSource, /* Source database handle */ 7128 const char *zSourceName /* Source database name */ 7129 ); 7130 SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage); 7131 SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p); 7132 SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p); 7133 SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p); 7134 7135 /* 7136 ** CAPI3REF: Unlock Notification 7137 ** METHOD: sqlite3 7138 ** 7139 ** ^When running in shared-cache mode, a database operation may fail with 7140 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7141 ** individual tables within the shared-cache cannot be obtained. See 7142 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7143 ** ^This API may be used to register a callback that SQLite will invoke 7144 ** when the connection currently holding the required lock relinquishes it. 7145 ** ^This API is only available if the library was compiled with the 7146 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7147 ** 7148 ** See Also: [Using the SQLite Unlock Notification Feature]. 7149 ** 7150 ** ^Shared-cache locks are released when a database connection concludes 7151 ** its current transaction, either by committing it or rolling it back. 7152 ** 7153 ** ^When a connection (known as the blocked connection) fails to obtain a 7154 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7155 ** identity of the database connection (the blocking connection) that 7156 ** has locked the required resource is stored internally. ^After an 7157 ** application receives an SQLITE_LOCKED error, it may call the 7158 ** sqlite3_unlock_notify() method with the blocked connection handle as 7159 ** the first argument to register for a callback that will be invoked 7160 ** when the blocking connections current transaction is concluded. ^The 7161 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7162 ** call that concludes the blocking connections transaction. 7163 ** 7164 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7165 ** there is a chance that the blocking connection will have already 7166 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7167 ** If this happens, then the specified callback is invoked immediately, 7168 ** from within the call to sqlite3_unlock_notify().)^ 7169 ** 7170 ** ^If the blocked connection is attempting to obtain a write-lock on a 7171 ** shared-cache table, and more than one other connection currently holds 7172 ** a read-lock on the same table, then SQLite arbitrarily selects one of 7173 ** the other connections to use as the blocking connection. 7174 ** 7175 ** ^(There may be at most one unlock-notify callback registered by a 7176 ** blocked connection. If sqlite3_unlock_notify() is called when the 7177 ** blocked connection already has a registered unlock-notify callback, 7178 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7179 ** called with a NULL pointer as its second argument, then any existing 7180 ** unlock-notify callback is canceled. ^The blocked connections 7181 ** unlock-notify callback may also be canceled by closing the blocked 7182 ** connection using [sqlite3_close()]. 7183 ** 7184 ** The unlock-notify callback is not reentrant. If an application invokes 7185 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7186 ** crash or deadlock may be the result. 7187 ** 7188 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7189 ** returns SQLITE_OK. 7190 ** 7191 ** <b>Callback Invocation Details</b> 7192 ** 7193 ** When an unlock-notify callback is registered, the application provides a 7194 ** single void* pointer that is passed to the callback when it is invoked. 7195 ** However, the signature of the callback function allows SQLite to pass 7196 ** it an array of void* context pointers. The first argument passed to 7197 ** an unlock-notify callback is a pointer to an array of void* pointers, 7198 ** and the second is the number of entries in the array. 7199 ** 7200 ** When a blocking connections transaction is concluded, there may be 7201 ** more than one blocked connection that has registered for an unlock-notify 7202 ** callback. ^If two or more such blocked connections have specified the 7203 ** same callback function, then instead of invoking the callback function 7204 ** multiple times, it is invoked once with the set of void* context pointers 7205 ** specified by the blocked connections bundled together into an array. 7206 ** This gives the application an opportunity to prioritize any actions 7207 ** related to the set of unblocked database connections. 7208 ** 7209 ** <b>Deadlock Detection</b> 7210 ** 7211 ** Assuming that after registering for an unlock-notify callback a 7212 ** database waits for the callback to be issued before taking any further 7213 ** action (a reasonable assumption), then using this API may cause the 7214 ** application to deadlock. For example, if connection X is waiting for 7215 ** connection Y's transaction to be concluded, and similarly connection 7216 ** Y is waiting on connection X's transaction, then neither connection 7217 ** will proceed and the system may remain deadlocked indefinitely. 7218 ** 7219 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7220 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7221 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7222 ** unlock-notify callback is registered. The system is said to be in 7223 ** a deadlocked state if connection A has registered for an unlock-notify 7224 ** callback on the conclusion of connection B's transaction, and connection 7225 ** B has itself registered for an unlock-notify callback when connection 7226 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7227 ** the system is also considered to be deadlocked if connection B has 7228 ** registered for an unlock-notify callback on the conclusion of connection 7229 ** C's transaction, where connection C is waiting on connection A. ^Any 7230 ** number of levels of indirection are allowed. 7231 ** 7232 ** <b>The "DROP TABLE" Exception</b> 7233 ** 7234 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7235 ** always appropriate to call sqlite3_unlock_notify(). There is however, 7236 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7237 ** SQLite checks if there are any currently executing SELECT statements 7238 ** that belong to the same connection. If there are, SQLITE_LOCKED is 7239 ** returned. In this case there is no "blocking connection", so invoking 7240 ** sqlite3_unlock_notify() results in the unlock-notify callback being 7241 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7242 ** or "DROP INDEX" query, an infinite loop might be the result. 7243 ** 7244 ** One way around this problem is to check the extended error code returned 7245 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7246 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7247 ** the special "DROP TABLE/INDEX" case, the extended error code is just 7248 ** SQLITE_LOCKED.)^ 7249 */ 7250 SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify( 7251 sqlite3 *pBlocked, /* Waiting connection */ 7252 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7253 void *pNotifyArg /* Argument to pass to xNotify */ 7254 ); 7255 7256 7257 /* 7258 ** CAPI3REF: String Comparison 7259 ** 7260 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7261 ** and extensions to compare the contents of two buffers containing UTF-8 7262 ** strings in a case-independent fashion, using the same definition of "case 7263 ** independence" that SQLite uses internally when comparing identifiers. 7264 */ 7265 SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *); 7266 SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int); 7267 7268 /* 7269 ** CAPI3REF: String Globbing 7270 * 7271 ** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7272 ** the glob pattern P, and it returns non-zero if string X does not match 7273 ** the glob pattern P. ^The definition of glob pattern matching used in 7274 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7275 ** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7276 ** sensitive. 7277 ** 7278 ** Note that this routine returns zero on a match and non-zero if the strings 7279 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7280 */ 7281 SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr); 7282 7283 /* 7284 ** CAPI3REF: Error Logging Interface 7285 ** 7286 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7287 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7288 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7289 ** used with [sqlite3_snprintf()] to generate the final output string. 7290 ** 7291 ** The sqlite3_log() interface is intended for use by extensions such as 7292 ** virtual tables, collating functions, and SQL functions. While there is 7293 ** nothing to prevent an application from calling sqlite3_log(), doing so 7294 ** is considered bad form. 7295 ** 7296 ** The zFormat string must not be NULL. 7297 ** 7298 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7299 ** will not use dynamically allocated memory. The log message is stored in 7300 ** a fixed-length buffer on the stack. If the log message is longer than 7301 ** a few hundred characters, it will be truncated to the length of the 7302 ** buffer. 7303 */ 7304 SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...); 7305 7306 /* 7307 ** CAPI3REF: Write-Ahead Log Commit Hook 7308 ** METHOD: sqlite3 7309 ** 7310 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 7311 ** is invoked each time data is committed to a database in wal mode. 7312 ** 7313 ** ^(The callback is invoked by SQLite after the commit has taken place and 7314 ** the associated write-lock on the database released)^, so the implementation 7315 ** may read, write or [checkpoint] the database as required. 7316 ** 7317 ** ^The first parameter passed to the callback function when it is invoked 7318 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 7319 ** registering the callback. ^The second is a copy of the database handle. 7320 ** ^The third parameter is the name of the database that was written to - 7321 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7322 ** is the number of pages currently in the write-ahead log file, 7323 ** including those that were just committed. 7324 ** 7325 ** The callback function should normally return [SQLITE_OK]. ^If an error 7326 ** code is returned, that error will propagate back up through the 7327 ** SQLite code base to cause the statement that provoked the callback 7328 ** to report an error, though the commit will have still occurred. If the 7329 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7330 ** that does not correspond to any valid SQLite error code, the results 7331 ** are undefined. 7332 ** 7333 ** A single database handle may have at most a single write-ahead log callback 7334 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7335 ** previously registered write-ahead log callback. ^Note that the 7336 ** [sqlite3_wal_autocheckpoint()] interface and the 7337 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7338 ** those overwrite any prior [sqlite3_wal_hook()] settings. 7339 */ 7340 SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook( 7341 sqlite3*, 7342 int(*)(void *,sqlite3*,const char*,int), 7343 void* 7344 ); 7345 7346 /* 7347 ** CAPI3REF: Configure an auto-checkpoint 7348 ** METHOD: sqlite3 7349 ** 7350 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7351 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 7352 ** to automatically [checkpoint] 7353 ** after committing a transaction if there are N or 7354 ** more frames in the [write-ahead log] file. ^Passing zero or 7355 ** a negative value as the nFrame parameter disables automatic 7356 ** checkpoints entirely. 7357 ** 7358 ** ^The callback registered by this function replaces any existing callback 7359 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7360 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7361 ** configured by this function. 7362 ** 7363 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7364 ** from SQL. 7365 ** 7366 ** ^Checkpoints initiated by this mechanism are 7367 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7368 ** 7369 ** ^Every new [database connection] defaults to having the auto-checkpoint 7370 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7371 ** pages. The use of this interface 7372 ** is only necessary if the default setting is found to be suboptimal 7373 ** for a particular application. 7374 */ 7375 SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7376 7377 /* 7378 ** CAPI3REF: Checkpoint a database 7379 ** METHOD: sqlite3 7380 ** 7381 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7382 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7383 ** 7384 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7385 ** [write-ahead log] for database X on [database connection] D to be 7386 ** transferred into the database file and for the write-ahead log to 7387 ** be reset. See the [checkpointing] documentation for addition 7388 ** information. 7389 ** 7390 ** This interface used to be the only way to cause a checkpoint to 7391 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7392 ** interface was added. This interface is retained for backwards 7393 ** compatibility and as a convenience for applications that need to manually 7394 ** start a callback but which do not need the full power (and corresponding 7395 ** complication) of [sqlite3_wal_checkpoint_v2()]. 7396 */ 7397 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7398 7399 /* 7400 ** CAPI3REF: Checkpoint a database 7401 ** METHOD: sqlite3 7402 ** 7403 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7404 ** operation on database X of [database connection] D in mode M. Status 7405 ** information is written back into integers pointed to by L and C.)^ 7406 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 7407 ** 7408 ** <dl> 7409 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7410 ** ^Checkpoint as many frames as possible without waiting for any database 7411 ** readers or writers to finish, then sync the database file if all frames 7412 ** in the log were checkpointed. ^The [busy-handler callback] 7413 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7414 ** ^On the other hand, passive mode might leave the checkpoint unfinished 7415 ** if there are concurrent readers or writers. 7416 ** 7417 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 7418 ** ^This mode blocks (it invokes the 7419 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 7420 ** database writer and all readers are reading from the most recent database 7421 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 7422 ** database file. ^This mode blocks new database writers while it is pending, 7423 ** but new database readers are allowed to continue unimpeded. 7424 ** 7425 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7426 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7427 ** that after checkpointing the log file it blocks (calls the 7428 ** [busy-handler callback]) 7429 ** until all readers are reading from the database file only. ^This ensures 7430 ** that the next writer will restart the log file from the beginning. 7431 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7432 ** database writer attempts while it is pending, but does not impede readers. 7433 ** 7434 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7435 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7436 ** addition that it also truncates the log file to zero bytes just prior 7437 ** to a successful return. 7438 ** </dl> 7439 ** 7440 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7441 ** the log file or to -1 if the checkpoint could not run because 7442 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7443 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7444 ** log file (including any that were already checkpointed before the function 7445 ** was called) or to -1 if the checkpoint could not run due to an error or 7446 ** because the database is not in WAL mode. ^Note that upon successful 7447 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7448 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7449 ** 7450 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7451 ** any other process is running a checkpoint operation at the same time, the 7452 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7453 ** busy-handler configured, it will not be invoked in this case. 7454 ** 7455 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7456 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7457 ** obtained immediately, and a busy-handler is configured, it is invoked and 7458 ** the writer lock retried until either the busy-handler returns 0 or the lock 7459 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 7460 ** database readers as described above. ^If the busy-handler returns 0 before 7461 ** the writer lock is obtained or while waiting for database readers, the 7462 ** checkpoint operation proceeds from that point in the same way as 7463 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7464 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 7465 ** 7466 ** ^If parameter zDb is NULL or points to a zero length string, then the 7467 ** specified operation is attempted on all WAL databases [attached] to 7468 ** [database connection] db. In this case the 7469 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7470 ** an SQLITE_BUSY error is encountered when processing one or more of the 7471 ** attached WAL databases, the operation is still attempted on any remaining 7472 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7473 ** error occurs while processing an attached database, processing is abandoned 7474 ** and the error code is returned to the caller immediately. ^If no error 7475 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7476 ** databases, SQLITE_OK is returned. 7477 ** 7478 ** ^If database zDb is the name of an attached database that is not in WAL 7479 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7480 ** zDb is not NULL (or a zero length string) and is not the name of any 7481 ** attached database, SQLITE_ERROR is returned to the caller. 7482 ** 7483 ** ^Unless it returns SQLITE_MISUSE, 7484 ** the sqlite3_wal_checkpoint_v2() interface 7485 ** sets the error information that is queried by 7486 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7487 ** 7488 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7489 ** from SQL. 7490 */ 7491 SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2( 7492 sqlite3 *db, /* Database handle */ 7493 const char *zDb, /* Name of attached database (or NULL) */ 7494 int eMode, /* SQLITE_CHECKPOINT_* value */ 7495 int *pnLog, /* OUT: Size of WAL log in frames */ 7496 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7497 ); 7498 7499 /* 7500 ** CAPI3REF: Checkpoint Mode Values 7501 ** KEYWORDS: {checkpoint mode} 7502 ** 7503 ** These constants define all valid values for the "checkpoint mode" passed 7504 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7505 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7506 ** meaning of each of these checkpoint modes. 7507 */ 7508 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7509 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7510 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7511 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7512 7513 /* 7514 ** CAPI3REF: Virtual Table Interface Configuration 7515 ** 7516 ** This function may be called by either the [xConnect] or [xCreate] method 7517 ** of a [virtual table] implementation to configure 7518 ** various facets of the virtual table interface. 7519 ** 7520 ** If this interface is invoked outside the context of an xConnect or 7521 ** xCreate virtual table method then the behavior is undefined. 7522 ** 7523 ** At present, there is only one option that may be configured using 7524 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7525 ** may be added in the future. 7526 */ 7527 SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...); 7528 7529 /* 7530 ** CAPI3REF: Virtual Table Configuration Options 7531 ** 7532 ** These macros define the various options to the 7533 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7534 ** can use to customize and optimize their behavior. 7535 ** 7536 ** <dl> 7537 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7538 ** <dd>Calls of the form 7539 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7540 ** where X is an integer. If X is zero, then the [virtual table] whose 7541 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7542 ** support constraints. In this configuration (which is the default) if 7543 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7544 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7545 ** specified as part of the users SQL statement, regardless of the actual 7546 ** ON CONFLICT mode specified. 7547 ** 7548 ** If X is non-zero, then the virtual table implementation guarantees 7549 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7550 ** any modifications to internal or persistent data structures have been made. 7551 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7552 ** is able to roll back a statement or database transaction, and abandon 7553 ** or continue processing the current SQL statement as appropriate. 7554 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7555 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7556 ** had been ABORT. 7557 ** 7558 ** Virtual table implementations that are required to handle OR REPLACE 7559 ** must do so within the [xUpdate] method. If a call to the 7560 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7561 ** CONFLICT policy is REPLACE, the virtual table implementation should 7562 ** silently replace the appropriate rows within the xUpdate callback and 7563 ** return SQLITE_OK. Or, if this is not possible, it may return 7564 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7565 ** constraint handling. 7566 ** </dl> 7567 */ 7568 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7569 7570 /* 7571 ** CAPI3REF: Determine The Virtual Table Conflict Policy 7572 ** 7573 ** This function may only be called from within a call to the [xUpdate] method 7574 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7575 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7576 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7577 ** of the SQL statement that triggered the call to the [xUpdate] method of the 7578 ** [virtual table]. 7579 */ 7580 SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *); 7581 7582 /* 7583 ** CAPI3REF: Conflict resolution modes 7584 ** KEYWORDS: {conflict resolution mode} 7585 ** 7586 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 7587 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 7588 ** is for the SQL statement being evaluated. 7589 ** 7590 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 7591 ** return value from the [sqlite3_set_authorizer()] callback and that 7592 ** [SQLITE_ABORT] is also a [result code]. 7593 */ 7594 #define SQLITE_ROLLBACK 1 7595 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7596 #define SQLITE_FAIL 3 7597 /* #define SQLITE_ABORT 4 // Also an error code */ 7598 #define SQLITE_REPLACE 5 7599 7600 /* 7601 ** CAPI3REF: Prepared Statement Scan Status Opcodes 7602 ** KEYWORDS: {scanstatus options} 7603 ** 7604 ** The following constants can be used for the T parameter to the 7605 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 7606 ** different metric for sqlite3_stmt_scanstatus() to return. 7607 ** 7608 ** When the value returned to V is a string, space to hold that string is 7609 ** managed by the prepared statement S and will be automatically freed when 7610 ** S is finalized. 7611 ** 7612 ** <dl> 7613 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 7614 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 7615 ** set to the total number of times that the X-th loop has run.</dd> 7616 ** 7617 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 7618 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 7619 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 7620 ** 7621 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 7622 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 7623 ** query planner's estimate for the average number of rows output from each 7624 ** iteration of the X-th loop. If the query planner's estimates was accurate, 7625 ** then this value will approximate the quotient NVISIT/NLOOP and the 7626 ** product of this value for all prior loops with the same SELECTID will 7627 ** be the NLOOP value for the current loop. 7628 ** 7629 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 7630 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 7631 ** to a zero-terminated UTF-8 string containing the name of the index or table 7632 ** used for the X-th loop. 7633 ** 7634 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 7635 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 7636 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 7637 ** description for the X-th loop. 7638 ** 7639 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 7640 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 7641 ** "select-id" for the X-th loop. The select-id identifies which query or 7642 ** subquery the loop is part of. The main query has a select-id of zero. 7643 ** The select-id is the same value as is output in the first column 7644 ** of an [EXPLAIN QUERY PLAN] query. 7645 ** </dl> 7646 */ 7647 #define SQLITE_SCANSTAT_NLOOP 0 7648 #define SQLITE_SCANSTAT_NVISIT 1 7649 #define SQLITE_SCANSTAT_EST 2 7650 #define SQLITE_SCANSTAT_NAME 3 7651 #define SQLITE_SCANSTAT_EXPLAIN 4 7652 #define SQLITE_SCANSTAT_SELECTID 5 7653 7654 /* 7655 ** CAPI3REF: Prepared Statement Scan Status 7656 ** METHOD: sqlite3_stmt 7657 ** 7658 ** This interface returns information about the predicted and measured 7659 ** performance for pStmt. Advanced applications can use this 7660 ** interface to compare the predicted and the measured performance and 7661 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 7662 ** 7663 ** Since this interface is expected to be rarely used, it is only 7664 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 7665 ** compile-time option. 7666 ** 7667 ** The "iScanStatusOp" parameter determines which status information to return. 7668 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 7669 ** of this interface is undefined. 7670 ** ^The requested measurement is written into a variable pointed to by 7671 ** the "pOut" parameter. 7672 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 7673 ** Loops are numbered starting from zero. ^If idx is out of range - less than 7674 ** zero or greater than or equal to the total number of loops used to implement 7675 ** the statement - a non-zero value is returned and the variable that pOut 7676 ** points to is unchanged. 7677 ** 7678 ** ^Statistics might not be available for all loops in all statements. ^In cases 7679 ** where there exist loops with no available statistics, this function behaves 7680 ** as if the loop did not exist - it returns non-zero and leave the variable 7681 ** that pOut points to unchanged. 7682 ** 7683 ** See also: [sqlite3_stmt_scanstatus_reset()] 7684 */ 7685 SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_stmt_scanstatus( 7686 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 7687 int idx, /* Index of loop to report on */ 7688 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 7689 void *pOut /* Result written here */ 7690 ); 7691 7692 /* 7693 ** CAPI3REF: Zero Scan-Status Counters 7694 ** METHOD: sqlite3_stmt 7695 ** 7696 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 7697 ** 7698 ** This API is only available if the library is built with pre-processor 7699 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 7700 */ 7701 SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 7702 7703 7704 /* 7705 ** Undo the hack that converts floating point types to integer for 7706 ** builds on processors without floating point support. 7707 */ 7708 #ifdef SQLITE_OMIT_FLOATING_POINT 7709 # undef double 7710 #endif 7711 7712 #ifdef __cplusplus 7713 } /* End of the 'extern "C"' block */ 7714 #endif 7715 #endif /* _SQLITE3_H_ */ 7716 7717 /* 7718 ** 2010 August 30 7719 ** 7720 ** The author disclaims copyright to this source code. In place of 7721 ** a legal notice, here is a blessing: 7722 ** 7723 ** May you do good and not evil. 7724 ** May you find forgiveness for yourself and forgive others. 7725 ** May you share freely, never taking more than you give. 7726 ** 7727 ************************************************************************* 7728 */ 7729 7730 #ifndef _SQLITE3RTREE_H_ 7731 #define _SQLITE3RTREE_H_ 7732 7733 7734 #ifdef __cplusplus 7735 extern "C" { 7736 #endif 7737 7738 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 7739 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 7740 7741 /* The double-precision datatype used by RTree depends on the 7742 ** SQLITE_RTREE_INT_ONLY compile-time option. 7743 */ 7744 #ifdef SQLITE_RTREE_INT_ONLY 7745 typedef sqlite3_int64 sqlite3_rtree_dbl; 7746 #else 7747 typedef double sqlite3_rtree_dbl; 7748 #endif 7749 7750 /* 7751 ** Register a geometry callback named zGeom that can be used as part of an 7752 ** R-Tree geometry query as follows: 7753 ** 7754 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 7755 */ 7756 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback( 7757 sqlite3 *db, 7758 const char *zGeom, 7759 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 7760 void *pContext 7761 ); 7762 7763 7764 /* 7765 ** A pointer to a structure of the following type is passed as the first 7766 ** argument to callbacks registered using rtree_geometry_callback(). 7767 */ 7768 struct sqlite3_rtree_geometry { 7769 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 7770 int nParam; /* Size of array aParam[] */ 7771 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 7772 void *pUser; /* Callback implementation user data */ 7773 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 7774 }; 7775 7776 /* 7777 ** Register a 2nd-generation geometry callback named zScore that can be 7778 ** used as part of an R-Tree geometry query as follows: 7779 ** 7780 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 7781 */ 7782 SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback( 7783 sqlite3 *db, 7784 const char *zQueryFunc, 7785 int (*xQueryFunc)(sqlite3_rtree_query_info*), 7786 void *pContext, 7787 void (*xDestructor)(void*) 7788 ); 7789 7790 7791 /* 7792 ** A pointer to a structure of the following type is passed as the 7793 ** argument to scored geometry callback registered using 7794 ** sqlite3_rtree_query_callback(). 7795 ** 7796 ** Note that the first 5 fields of this structure are identical to 7797 ** sqlite3_rtree_geometry. This structure is a subclass of 7798 ** sqlite3_rtree_geometry. 7799 */ 7800 struct sqlite3_rtree_query_info { 7801 void *pContext; /* pContext from when function registered */ 7802 int nParam; /* Number of function parameters */ 7803 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 7804 void *pUser; /* callback can use this, if desired */ 7805 void (*xDelUser)(void*); /* function to free pUser */ 7806 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 7807 unsigned int *anQueue; /* Number of pending entries in the queue */ 7808 int nCoord; /* Number of coordinates */ 7809 int iLevel; /* Level of current node or entry */ 7810 int mxLevel; /* The largest iLevel value in the tree */ 7811 sqlite3_int64 iRowid; /* Rowid for current entry */ 7812 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 7813 int eParentWithin; /* Visibility of parent node */ 7814 int eWithin; /* OUT: Visiblity */ 7815 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 7816 }; 7817 7818 /* 7819 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 7820 */ 7821 #define NOT_WITHIN 0 /* Object completely outside of query region */ 7822 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 7823 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 7824 7825 7826 #ifdef __cplusplus 7827 } /* end of the 'extern "C"' block */ 7828 #endif 7829 7830 #endif /* ifndef _SQLITE3RTREE_H_ */ 7831 7832
