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