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| 1 /* |
| 2 ** 2001 September 15 |
| 3 ** |
| 4 ** The author disclaims copyright to this source code. In place of |
| 5 ** a legal notice, here is a blessing: |
| 6 ** |
| 7 ** May you do good and not evil. |
| 8 ** May you find forgiveness for yourself and forgive others. |
| 9 ** May you share freely, never taking more than you give. |
| 10 ** |
| 11 ************************************************************************* |
| 12 ** This header file defines the interface that the SQLite library |
| 13 ** presents to client programs. If a C-function, structure, datatype, |
| 14 ** or constant definition does not appear in this file, then it is |
| 15 ** not a published API of SQLite, is subject to change without |
| 16 ** notice, and should not be referenced by programs that use SQLite. |
| 17 ** |
| 18 ** Some of the definitions that are in this file are marked as |
| 19 ** "experimental". Experimental interfaces are normally new |
| 20 ** features recently added to SQLite. We do not anticipate changes |
| 21 ** to experimental interfaces but reserve the right to make minor changes |
| 22 ** if experience from use "in the wild" suggest such changes are prudent. |
| 23 ** |
| 24 ** The official C-language API documentation for SQLite is derived |
| 25 ** from comments in this file. This file is the authoritative source |
| 26 ** on how SQLite interfaces are supposed to operate. |
| 27 ** |
| 28 ** The name of this file under configuration management is "sqlite.h.in". |
| 29 ** The makefile makes some minor changes to this file (such as inserting |
| 30 ** the version number) and changes its name to "sqlite3.h" as |
| 31 ** part of the build process. |
| 32 */ |
| 33 #ifndef SQLITE3_H |
| 34 #define SQLITE3_H |
| 35 #include <stdarg.h> /* Needed for the definition of va_list */ |
| 36 |
| 37 /* |
| 38 ** Make sure we can call this stuff from C++. |
| 39 */ |
| 40 #ifdef __cplusplus |
| 41 extern "C" { |
| 42 #endif |
| 43 |
| 44 |
| 45 /* |
| 46 ** Provide the ability to override linkage features of the interface. |
| 47 */ |
| 48 #ifndef SQLITE_EXTERN |
| 49 # define SQLITE_EXTERN extern |
| 50 #endif |
| 51 #ifndef SQLITE_API |
| 52 # define SQLITE_API |
| 53 #endif |
| 54 #ifndef SQLITE_CDECL |
| 55 # define SQLITE_CDECL |
| 56 #endif |
| 57 #ifndef SQLITE_APICALL |
| 58 # define SQLITE_APICALL |
| 59 #endif |
| 60 #ifndef SQLITE_STDCALL |
| 61 # define SQLITE_STDCALL SQLITE_APICALL |
| 62 #endif |
| 63 #ifndef SQLITE_CALLBACK |
| 64 # define SQLITE_CALLBACK |
| 65 #endif |
| 66 #ifndef SQLITE_SYSAPI |
| 67 # define SQLITE_SYSAPI |
| 68 #endif |
| 69 |
| 70 /* |
| 71 ** These no-op macros are used in front of interfaces to mark those |
| 72 ** interfaces as either deprecated or experimental. New applications |
| 73 ** should not use deprecated interfaces - they are supported for backwards |
| 74 ** compatibility only. Application writers should be aware that |
| 75 ** experimental interfaces are subject to change in point releases. |
| 76 ** |
| 77 ** These macros used to resolve to various kinds of compiler magic that |
| 78 ** would generate warning messages when they were used. But that |
| 79 ** compiler magic ended up generating such a flurry of bug reports |
| 80 ** that we have taken it all out and gone back to using simple |
| 81 ** noop macros. |
| 82 */ |
| 83 #define SQLITE_DEPRECATED |
| 84 #define SQLITE_EXPERIMENTAL |
| 85 |
| 86 /* |
| 87 ** Ensure these symbols were not defined by some previous header file. |
| 88 */ |
| 89 #ifdef SQLITE_VERSION |
| 90 # undef SQLITE_VERSION |
| 91 #endif |
| 92 #ifdef SQLITE_VERSION_NUMBER |
| 93 # undef SQLITE_VERSION_NUMBER |
| 94 #endif |
| 95 |
| 96 /* |
| 97 ** CAPI3REF: Compile-Time Library Version Numbers |
| 98 ** |
| 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header |
| 100 ** evaluates to a string literal that is the SQLite version in the |
| 101 ** format "X.Y.Z" where X is the major version number (always 3 for |
| 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ |
| 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer |
| 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same |
| 105 ** numbers used in [SQLITE_VERSION].)^ |
| 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also |
| 107 ** be larger than the release from which it is derived. Either Y will |
| 108 ** be held constant and Z will be incremented or else Y will be incremented |
| 109 ** and Z will be reset to zero. |
| 110 ** |
| 111 ** Since [version 3.6.18] ([dateof:3.6.18]), |
| 112 ** SQLite source code has been stored in the |
| 113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management |
| 114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to |
| 115 ** a string which identifies a particular check-in of SQLite |
| 116 ** within its configuration management system. ^The SQLITE_SOURCE_ID |
| 117 ** string contains the date and time of the check-in (UTC) and an SHA1 |
| 118 ** hash of the entire source tree. |
| 119 ** |
| 120 ** See also: [sqlite3_libversion()], |
| 121 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], |
| 122 ** [sqlite_version()] and [sqlite_source_id()]. |
| 123 */ |
| 124 #define SQLITE_VERSION "--VERS--" |
| 125 #define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- |
| 126 #define SQLITE_SOURCE_ID "--SOURCE-ID--" |
| 127 |
| 128 /* |
| 129 ** CAPI3REF: Run-Time Library Version Numbers |
| 130 ** KEYWORDS: sqlite3_version sqlite3_sourceid |
| 131 ** |
| 132 ** These interfaces provide the same information as the [SQLITE_VERSION], |
| 133 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros |
| 134 ** but are associated with the library instead of the header file. ^(Cautious |
| 135 ** programmers might include assert() statements in their application to |
| 136 ** verify that values returned by these interfaces match the macros in |
| 137 ** the header, and thus ensure that the application is |
| 138 ** compiled with matching library and header files. |
| 139 ** |
| 140 ** <blockquote><pre> |
| 141 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); |
| 142 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); |
| 143 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); |
| 144 ** </pre></blockquote>)^ |
| 145 ** |
| 146 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] |
| 147 ** macro. ^The sqlite3_libversion() function returns a pointer to the |
| 148 ** to the sqlite3_version[] string constant. The sqlite3_libversion() |
| 149 ** function is provided for use in DLLs since DLL users usually do not have |
| 150 ** direct access to string constants within the DLL. ^The |
| 151 ** sqlite3_libversion_number() function returns an integer equal to |
| 152 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns |
| 153 ** a pointer to a string constant whose value is the same as the |
| 154 ** [SQLITE_SOURCE_ID] C preprocessor macro. |
| 155 ** |
| 156 ** See also: [sqlite_version()] and [sqlite_source_id()]. |
| 157 */ |
| 158 SQLITE_EXTERN const char sqlite3_version[]; |
| 159 const char *sqlite3_libversion(void); |
| 160 const char *sqlite3_sourceid(void); |
| 161 int sqlite3_libversion_number(void); |
| 162 |
| 163 /* |
| 164 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics |
| 165 ** |
| 166 ** ^The sqlite3_compileoption_used() function returns 0 or 1 |
| 167 ** indicating whether the specified option was defined at |
| 168 ** compile time. ^The SQLITE_ prefix may be omitted from the |
| 169 ** option name passed to sqlite3_compileoption_used(). |
| 170 ** |
| 171 ** ^The sqlite3_compileoption_get() function allows iterating |
| 172 ** over the list of options that were defined at compile time by |
| 173 ** returning the N-th compile time option string. ^If N is out of range, |
| 174 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ |
| 175 ** prefix is omitted from any strings returned by |
| 176 ** sqlite3_compileoption_get(). |
| 177 ** |
| 178 ** ^Support for the diagnostic functions sqlite3_compileoption_used() |
| 179 ** and sqlite3_compileoption_get() may be omitted by specifying the |
| 180 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. |
| 181 ** |
| 182 ** See also: SQL functions [sqlite_compileoption_used()] and |
| 183 ** [sqlite_compileoption_get()] and the [compile_options pragma]. |
| 184 */ |
| 185 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS |
| 186 int sqlite3_compileoption_used(const char *zOptName); |
| 187 const char *sqlite3_compileoption_get(int N); |
| 188 #endif |
| 189 |
| 190 /* |
| 191 ** CAPI3REF: Test To See If The Library Is Threadsafe |
| 192 ** |
| 193 ** ^The sqlite3_threadsafe() function returns zero if and only if |
| 194 ** SQLite was compiled with mutexing code omitted due to the |
| 195 ** [SQLITE_THREADSAFE] compile-time option being set to 0. |
| 196 ** |
| 197 ** SQLite can be compiled with or without mutexes. When |
| 198 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes |
| 199 ** are enabled and SQLite is threadsafe. When the |
| 200 ** [SQLITE_THREADSAFE] macro is 0, |
| 201 ** the mutexes are omitted. Without the mutexes, it is not safe |
| 202 ** to use SQLite concurrently from more than one thread. |
| 203 ** |
| 204 ** Enabling mutexes incurs a measurable performance penalty. |
| 205 ** So if speed is of utmost importance, it makes sense to disable |
| 206 ** the mutexes. But for maximum safety, mutexes should be enabled. |
| 207 ** ^The default behavior is for mutexes to be enabled. |
| 208 ** |
| 209 ** This interface can be used by an application to make sure that the |
| 210 ** version of SQLite that it is linking against was compiled with |
| 211 ** the desired setting of the [SQLITE_THREADSAFE] macro. |
| 212 ** |
| 213 ** This interface only reports on the compile-time mutex setting |
| 214 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with |
| 215 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but |
| 216 ** can be fully or partially disabled using a call to [sqlite3_config()] |
| 217 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], |
| 218 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the |
| 219 ** sqlite3_threadsafe() function shows only the compile-time setting of |
| 220 ** thread safety, not any run-time changes to that setting made by |
| 221 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() |
| 222 ** is unchanged by calls to sqlite3_config().)^ |
| 223 ** |
| 224 ** See the [threading mode] documentation for additional information. |
| 225 */ |
| 226 int sqlite3_threadsafe(void); |
| 227 |
| 228 /* |
| 229 ** CAPI3REF: Database Connection Handle |
| 230 ** KEYWORDS: {database connection} {database connections} |
| 231 ** |
| 232 ** Each open SQLite database is represented by a pointer to an instance of |
| 233 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 |
| 234 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and |
| 235 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] |
| 236 ** and [sqlite3_close_v2()] are its destructors. There are many other |
| 237 ** interfaces (such as |
| 238 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and |
| 239 ** [sqlite3_busy_timeout()] to name but three) that are methods on an |
| 240 ** sqlite3 object. |
| 241 */ |
| 242 typedef struct sqlite3 sqlite3; |
| 243 |
| 244 /* |
| 245 ** CAPI3REF: 64-Bit Integer Types |
| 246 ** KEYWORDS: sqlite_int64 sqlite_uint64 |
| 247 ** |
| 248 ** Because there is no cross-platform way to specify 64-bit integer types |
| 249 ** SQLite includes typedefs for 64-bit signed and unsigned integers. |
| 250 ** |
| 251 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. |
| 252 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards |
| 253 ** compatibility only. |
| 254 ** |
| 255 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values |
| 256 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The |
| 257 ** sqlite3_uint64 and sqlite_uint64 types can store integer values |
| 258 ** between 0 and +18446744073709551615 inclusive. |
| 259 */ |
| 260 #ifdef SQLITE_INT64_TYPE |
| 261 typedef SQLITE_INT64_TYPE sqlite_int64; |
| 262 # ifdef SQLITE_UINT64_TYPE |
| 263 typedef SQLITE_UINT64_TYPE sqlite_uint64; |
| 264 # else |
| 265 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; |
| 266 # endif |
| 267 #elif defined(_MSC_VER) || defined(__BORLANDC__) |
| 268 typedef __int64 sqlite_int64; |
| 269 typedef unsigned __int64 sqlite_uint64; |
| 270 #else |
| 271 typedef long long int sqlite_int64; |
| 272 typedef unsigned long long int sqlite_uint64; |
| 273 #endif |
| 274 typedef sqlite_int64 sqlite3_int64; |
| 275 typedef sqlite_uint64 sqlite3_uint64; |
| 276 |
| 277 /* |
| 278 ** If compiling for a processor that lacks floating point support, |
| 279 ** substitute integer for floating-point. |
| 280 */ |
| 281 #ifdef SQLITE_OMIT_FLOATING_POINT |
| 282 # define double sqlite3_int64 |
| 283 #endif |
| 284 |
| 285 /* |
| 286 ** CAPI3REF: Closing A Database Connection |
| 287 ** DESTRUCTOR: sqlite3 |
| 288 ** |
| 289 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors |
| 290 ** for the [sqlite3] object. |
| 291 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if |
| 292 ** the [sqlite3] object is successfully destroyed and all associated |
| 293 ** resources are deallocated. |
| 294 ** |
| 295 ** ^If the database connection is associated with unfinalized prepared |
| 296 ** statements or unfinished sqlite3_backup objects then sqlite3_close() |
| 297 ** will leave the database connection open and return [SQLITE_BUSY]. |
| 298 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements |
| 299 ** and/or unfinished sqlite3_backups, then the database connection becomes |
| 300 ** an unusable "zombie" which will automatically be deallocated when the |
| 301 ** last prepared statement is finalized or the last sqlite3_backup is |
| 302 ** finished. The sqlite3_close_v2() interface is intended for use with |
| 303 ** host languages that are garbage collected, and where the order in which |
| 304 ** destructors are called is arbitrary. |
| 305 ** |
| 306 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], |
| 307 ** [sqlite3_blob_close | close] all [BLOB handles], and |
| 308 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated |
| 309 ** with the [sqlite3] object prior to attempting to close the object. ^If |
| 310 ** sqlite3_close_v2() is called on a [database connection] that still has |
| 311 ** outstanding [prepared statements], [BLOB handles], and/or |
| 312 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation |
| 313 ** of resources is deferred until all [prepared statements], [BLOB handles], |
| 314 ** and [sqlite3_backup] objects are also destroyed. |
| 315 ** |
| 316 ** ^If an [sqlite3] object is destroyed while a transaction is open, |
| 317 ** the transaction is automatically rolled back. |
| 318 ** |
| 319 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] |
| 320 ** must be either a NULL |
| 321 ** pointer or an [sqlite3] object pointer obtained |
| 322 ** from [sqlite3_open()], [sqlite3_open16()], or |
| 323 ** [sqlite3_open_v2()], and not previously closed. |
| 324 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer |
| 325 ** argument is a harmless no-op. |
| 326 */ |
| 327 int sqlite3_close(sqlite3*); |
| 328 int sqlite3_close_v2(sqlite3*); |
| 329 |
| 330 /* |
| 331 ** The type for a callback function. |
| 332 ** This is legacy and deprecated. It is included for historical |
| 333 ** compatibility and is not documented. |
| 334 */ |
| 335 typedef int (*sqlite3_callback)(void*,int,char**, char**); |
| 336 |
| 337 /* |
| 338 ** CAPI3REF: One-Step Query Execution Interface |
| 339 ** METHOD: sqlite3 |
| 340 ** |
| 341 ** The sqlite3_exec() interface is a convenience wrapper around |
| 342 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], |
| 343 ** that allows an application to run multiple statements of SQL |
| 344 ** without having to use a lot of C code. |
| 345 ** |
| 346 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, |
| 347 ** semicolon-separate SQL statements passed into its 2nd argument, |
| 348 ** in the context of the [database connection] passed in as its 1st |
| 349 ** argument. ^If the callback function of the 3rd argument to |
| 350 ** sqlite3_exec() is not NULL, then it is invoked for each result row |
| 351 ** coming out of the evaluated SQL statements. ^The 4th argument to |
| 352 ** sqlite3_exec() is relayed through to the 1st argument of each |
| 353 ** callback invocation. ^If the callback pointer to sqlite3_exec() |
| 354 ** is NULL, then no callback is ever invoked and result rows are |
| 355 ** ignored. |
| 356 ** |
| 357 ** ^If an error occurs while evaluating the SQL statements passed into |
| 358 ** sqlite3_exec(), then execution of the current statement stops and |
| 359 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() |
| 360 ** is not NULL then any error message is written into memory obtained |
| 361 ** from [sqlite3_malloc()] and passed back through the 5th parameter. |
| 362 ** To avoid memory leaks, the application should invoke [sqlite3_free()] |
| 363 ** on error message strings returned through the 5th parameter of |
| 364 ** sqlite3_exec() after the error message string is no longer needed. |
| 365 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors |
| 366 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to |
| 367 ** NULL before returning. |
| 368 ** |
| 369 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() |
| 370 ** routine returns SQLITE_ABORT without invoking the callback again and |
| 371 ** without running any subsequent SQL statements. |
| 372 ** |
| 373 ** ^The 2nd argument to the sqlite3_exec() callback function is the |
| 374 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() |
| 375 ** callback is an array of pointers to strings obtained as if from |
| 376 ** [sqlite3_column_text()], one for each column. ^If an element of a |
| 377 ** result row is NULL then the corresponding string pointer for the |
| 378 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the |
| 379 ** sqlite3_exec() callback is an array of pointers to strings where each |
| 380 ** entry represents the name of corresponding result column as obtained |
| 381 ** from [sqlite3_column_name()]. |
| 382 ** |
| 383 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer |
| 384 ** to an empty string, or a pointer that contains only whitespace and/or |
| 385 ** SQL comments, then no SQL statements are evaluated and the database |
| 386 ** is not changed. |
| 387 ** |
| 388 ** Restrictions: |
| 389 ** |
| 390 ** <ul> |
| 391 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() |
| 392 ** is a valid and open [database connection]. |
| 393 ** <li> The application must not close the [database connection] specified by |
| 394 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. |
| 395 ** <li> The application must not modify the SQL statement text passed into |
| 396 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. |
| 397 ** </ul> |
| 398 */ |
| 399 int sqlite3_exec( |
| 400 sqlite3*, /* An open database */ |
| 401 const char *sql, /* SQL to be evaluated */ |
| 402 int (*callback)(void*,int,char**,char**), /* Callback function */ |
| 403 void *, /* 1st argument to callback */ |
| 404 char **errmsg /* Error msg written here */ |
| 405 ); |
| 406 |
| 407 /* |
| 408 ** CAPI3REF: Result Codes |
| 409 ** KEYWORDS: {result code definitions} |
| 410 ** |
| 411 ** Many SQLite functions return an integer result code from the set shown |
| 412 ** here in order to indicate success or failure. |
| 413 ** |
| 414 ** New error codes may be added in future versions of SQLite. |
| 415 ** |
| 416 ** See also: [extended result code definitions] |
| 417 */ |
| 418 #define SQLITE_OK 0 /* Successful result */ |
| 419 /* beginning-of-error-codes */ |
| 420 #define SQLITE_ERROR 1 /* SQL error or missing database */ |
| 421 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ |
| 422 #define SQLITE_PERM 3 /* Access permission denied */ |
| 423 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ |
| 424 #define SQLITE_BUSY 5 /* The database file is locked */ |
| 425 #define SQLITE_LOCKED 6 /* A table in the database is locked */ |
| 426 #define SQLITE_NOMEM 7 /* A malloc() failed */ |
| 427 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ |
| 428 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ |
| 429 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ |
| 430 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ |
| 431 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ |
| 432 #define SQLITE_FULL 13 /* Insertion failed because database is full */ |
| 433 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ |
| 434 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ |
| 435 #define SQLITE_EMPTY 16 /* Database is empty */ |
| 436 #define SQLITE_SCHEMA 17 /* The database schema changed */ |
| 437 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ |
| 438 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ |
| 439 #define SQLITE_MISMATCH 20 /* Data type mismatch */ |
| 440 #define SQLITE_MISUSE 21 /* Library used incorrectly */ |
| 441 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ |
| 442 #define SQLITE_AUTH 23 /* Authorization denied */ |
| 443 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ |
| 444 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ |
| 445 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ |
| 446 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ |
| 447 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ |
| 448 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ |
| 449 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ |
| 450 /* end-of-error-codes */ |
| 451 |
| 452 /* |
| 453 ** CAPI3REF: Extended Result Codes |
| 454 ** KEYWORDS: {extended result code definitions} |
| 455 ** |
| 456 ** In its default configuration, SQLite API routines return one of 30 integer |
| 457 ** [result codes]. However, experience has shown that many of |
| 458 ** these result codes are too coarse-grained. They do not provide as |
| 459 ** much information about problems as programmers might like. In an effort to |
| 460 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] |
| 461 ** and later) include |
| 462 ** support for additional result codes that provide more detailed information |
| 463 ** about errors. These [extended result codes] are enabled or disabled |
| 464 ** on a per database connection basis using the |
| 465 ** [sqlite3_extended_result_codes()] API. Or, the extended code for |
| 466 ** the most recent error can be obtained using |
| 467 ** [sqlite3_extended_errcode()]. |
| 468 */ |
| 469 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) |
| 470 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) |
| 471 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) |
| 472 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) |
| 473 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) |
| 474 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) |
| 475 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) |
| 476 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) |
| 477 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) |
| 478 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) |
| 479 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) |
| 480 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) |
| 481 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) |
| 482 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) |
| 483 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) |
| 484 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) |
| 485 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) |
| 486 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) |
| 487 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) |
| 488 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) |
| 489 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) |
| 490 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) |
| 491 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) |
| 492 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) |
| 493 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) |
| 494 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) |
| 495 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) |
| 496 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) |
| 497 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) |
| 498 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) |
| 499 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) |
| 500 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) |
| 501 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) |
| 502 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) |
| 503 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) |
| 504 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) |
| 505 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) |
| 506 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) |
| 507 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) |
| 508 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) |
| 509 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) |
| 510 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) |
| 511 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) |
| 512 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) |
| 513 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) |
| 514 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) |
| 515 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) |
| 516 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) |
| 517 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) |
| 518 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) |
| 519 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) |
| 520 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) |
| 521 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) |
| 522 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) |
| 523 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) |
| 524 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) |
| 525 |
| 526 /* |
| 527 ** CAPI3REF: Flags For File Open Operations |
| 528 ** |
| 529 ** These bit values are intended for use in the |
| 530 ** 3rd parameter to the [sqlite3_open_v2()] interface and |
| 531 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. |
| 532 */ |
| 533 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ |
| 534 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ |
| 535 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ |
| 536 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ |
| 537 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ |
| 538 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ |
| 539 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ |
| 540 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ |
| 541 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ |
| 542 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ |
| 543 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ |
| 544 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ |
| 545 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ |
| 546 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ |
| 547 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ |
| 548 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ |
| 549 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ |
| 550 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ |
| 551 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ |
| 552 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ |
| 553 |
| 554 /* Reserved: 0x00F00000 */ |
| 555 |
| 556 /* |
| 557 ** CAPI3REF: Device Characteristics |
| 558 ** |
| 559 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] |
| 560 ** object returns an integer which is a vector of these |
| 561 ** bit values expressing I/O characteristics of the mass storage |
| 562 ** device that holds the file that the [sqlite3_io_methods] |
| 563 ** refers to. |
| 564 ** |
| 565 ** The SQLITE_IOCAP_ATOMIC property means that all writes of |
| 566 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values |
| 567 ** mean that writes of blocks that are nnn bytes in size and |
| 568 ** are aligned to an address which is an integer multiple of |
| 569 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means |
| 570 ** that when data is appended to a file, the data is appended |
| 571 ** first then the size of the file is extended, never the other |
| 572 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that |
| 573 ** information is written to disk in the same order as calls |
| 574 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that |
| 575 ** after reboot following a crash or power loss, the only bytes in a |
| 576 ** file that were written at the application level might have changed |
| 577 ** and that adjacent bytes, even bytes within the same sector are |
| 578 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN |
| 579 ** flag indicates that a file cannot be deleted when open. The |
| 580 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on |
| 581 ** read-only media and cannot be changed even by processes with |
| 582 ** elevated privileges. |
| 583 */ |
| 584 #define SQLITE_IOCAP_ATOMIC 0x00000001 |
| 585 #define SQLITE_IOCAP_ATOMIC512 0x00000002 |
| 586 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 |
| 587 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 |
| 588 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 |
| 589 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 |
| 590 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 |
| 591 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 |
| 592 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 |
| 593 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 |
| 594 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 |
| 595 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 |
| 596 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 |
| 597 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 |
| 598 |
| 599 /* |
| 600 ** CAPI3REF: File Locking Levels |
| 601 ** |
| 602 ** SQLite uses one of these integer values as the second |
| 603 ** argument to calls it makes to the xLock() and xUnlock() methods |
| 604 ** of an [sqlite3_io_methods] object. |
| 605 */ |
| 606 #define SQLITE_LOCK_NONE 0 |
| 607 #define SQLITE_LOCK_SHARED 1 |
| 608 #define SQLITE_LOCK_RESERVED 2 |
| 609 #define SQLITE_LOCK_PENDING 3 |
| 610 #define SQLITE_LOCK_EXCLUSIVE 4 |
| 611 |
| 612 /* |
| 613 ** CAPI3REF: Synchronization Type Flags |
| 614 ** |
| 615 ** When SQLite invokes the xSync() method of an |
| 616 ** [sqlite3_io_methods] object it uses a combination of |
| 617 ** these integer values as the second argument. |
| 618 ** |
| 619 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the |
| 620 ** sync operation only needs to flush data to mass storage. Inode |
| 621 ** information need not be flushed. If the lower four bits of the flag |
| 622 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. |
| 623 ** If the lower four bits equal SQLITE_SYNC_FULL, that means |
| 624 ** to use Mac OS X style fullsync instead of fsync(). |
| 625 ** |
| 626 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags |
| 627 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL |
| 628 ** settings. The [synchronous pragma] determines when calls to the |
| 629 ** xSync VFS method occur and applies uniformly across all platforms. |
| 630 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how |
| 631 ** energetic or rigorous or forceful the sync operations are and |
| 632 ** only make a difference on Mac OSX for the default SQLite code. |
| 633 ** (Third-party VFS implementations might also make the distinction |
| 634 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the |
| 635 ** operating systems natively supported by SQLite, only Mac OSX |
| 636 ** cares about the difference.) |
| 637 */ |
| 638 #define SQLITE_SYNC_NORMAL 0x00002 |
| 639 #define SQLITE_SYNC_FULL 0x00003 |
| 640 #define SQLITE_SYNC_DATAONLY 0x00010 |
| 641 |
| 642 /* |
| 643 ** CAPI3REF: OS Interface Open File Handle |
| 644 ** |
| 645 ** An [sqlite3_file] object represents an open file in the |
| 646 ** [sqlite3_vfs | OS interface layer]. Individual OS interface |
| 647 ** implementations will |
| 648 ** want to subclass this object by appending additional fields |
| 649 ** for their own use. The pMethods entry is a pointer to an |
| 650 ** [sqlite3_io_methods] object that defines methods for performing |
| 651 ** I/O operations on the open file. |
| 652 */ |
| 653 typedef struct sqlite3_file sqlite3_file; |
| 654 struct sqlite3_file { |
| 655 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ |
| 656 }; |
| 657 |
| 658 /* |
| 659 ** CAPI3REF: OS Interface File Virtual Methods Object |
| 660 ** |
| 661 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an |
| 662 ** [sqlite3_file] object (or, more commonly, a subclass of the |
| 663 ** [sqlite3_file] object) with a pointer to an instance of this object. |
| 664 ** This object defines the methods used to perform various operations |
| 665 ** against the open file represented by the [sqlite3_file] object. |
| 666 ** |
| 667 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element |
| 668 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method |
| 669 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The |
| 670 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] |
| 671 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element |
| 672 ** to NULL. |
| 673 ** |
| 674 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or |
| 675 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). |
| 676 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] |
| 677 ** flag may be ORed in to indicate that only the data of the file |
| 678 ** and not its inode needs to be synced. |
| 679 ** |
| 680 ** The integer values to xLock() and xUnlock() are one of |
| 681 ** <ul> |
| 682 ** <li> [SQLITE_LOCK_NONE], |
| 683 ** <li> [SQLITE_LOCK_SHARED], |
| 684 ** <li> [SQLITE_LOCK_RESERVED], |
| 685 ** <li> [SQLITE_LOCK_PENDING], or |
| 686 ** <li> [SQLITE_LOCK_EXCLUSIVE]. |
| 687 ** </ul> |
| 688 ** xLock() increases the lock. xUnlock() decreases the lock. |
| 689 ** The xCheckReservedLock() method checks whether any database connection, |
| 690 ** either in this process or in some other process, is holding a RESERVED, |
| 691 ** PENDING, or EXCLUSIVE lock on the file. It returns true |
| 692 ** if such a lock exists and false otherwise. |
| 693 ** |
| 694 ** The xFileControl() method is a generic interface that allows custom |
| 695 ** VFS implementations to directly control an open file using the |
| 696 ** [sqlite3_file_control()] interface. The second "op" argument is an |
| 697 ** integer opcode. The third argument is a generic pointer intended to |
| 698 ** point to a structure that may contain arguments or space in which to |
| 699 ** write return values. Potential uses for xFileControl() might be |
| 700 ** functions to enable blocking locks with timeouts, to change the |
| 701 ** locking strategy (for example to use dot-file locks), to inquire |
| 702 ** about the status of a lock, or to break stale locks. The SQLite |
| 703 ** core reserves all opcodes less than 100 for its own use. |
| 704 ** A [file control opcodes | list of opcodes] less than 100 is available. |
| 705 ** Applications that define a custom xFileControl method should use opcodes |
| 706 ** greater than 100 to avoid conflicts. VFS implementations should |
| 707 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not |
| 708 ** recognize. |
| 709 ** |
| 710 ** The xSectorSize() method returns the sector size of the |
| 711 ** device that underlies the file. The sector size is the |
| 712 ** minimum write that can be performed without disturbing |
| 713 ** other bytes in the file. The xDeviceCharacteristics() |
| 714 ** method returns a bit vector describing behaviors of the |
| 715 ** underlying device: |
| 716 ** |
| 717 ** <ul> |
| 718 ** <li> [SQLITE_IOCAP_ATOMIC] |
| 719 ** <li> [SQLITE_IOCAP_ATOMIC512] |
| 720 ** <li> [SQLITE_IOCAP_ATOMIC1K] |
| 721 ** <li> [SQLITE_IOCAP_ATOMIC2K] |
| 722 ** <li> [SQLITE_IOCAP_ATOMIC4K] |
| 723 ** <li> [SQLITE_IOCAP_ATOMIC8K] |
| 724 ** <li> [SQLITE_IOCAP_ATOMIC16K] |
| 725 ** <li> [SQLITE_IOCAP_ATOMIC32K] |
| 726 ** <li> [SQLITE_IOCAP_ATOMIC64K] |
| 727 ** <li> [SQLITE_IOCAP_SAFE_APPEND] |
| 728 ** <li> [SQLITE_IOCAP_SEQUENTIAL] |
| 729 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] |
| 730 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] |
| 731 ** <li> [SQLITE_IOCAP_IMMUTABLE] |
| 732 ** </ul> |
| 733 ** |
| 734 ** The SQLITE_IOCAP_ATOMIC property means that all writes of |
| 735 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values |
| 736 ** mean that writes of blocks that are nnn bytes in size and |
| 737 ** are aligned to an address which is an integer multiple of |
| 738 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means |
| 739 ** that when data is appended to a file, the data is appended |
| 740 ** first then the size of the file is extended, never the other |
| 741 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that |
| 742 ** information is written to disk in the same order as calls |
| 743 ** to xWrite(). |
| 744 ** |
| 745 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill |
| 746 ** in the unread portions of the buffer with zeros. A VFS that |
| 747 ** fails to zero-fill short reads might seem to work. However, |
| 748 ** failure to zero-fill short reads will eventually lead to |
| 749 ** database corruption. |
| 750 */ |
| 751 typedef struct sqlite3_io_methods sqlite3_io_methods; |
| 752 struct sqlite3_io_methods { |
| 753 int iVersion; |
| 754 int (*xClose)(sqlite3_file*); |
| 755 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); |
| 756 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); |
| 757 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); |
| 758 int (*xSync)(sqlite3_file*, int flags); |
| 759 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); |
| 760 int (*xLock)(sqlite3_file*, int); |
| 761 int (*xUnlock)(sqlite3_file*, int); |
| 762 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); |
| 763 int (*xFileControl)(sqlite3_file*, int op, void *pArg); |
| 764 int (*xSectorSize)(sqlite3_file*); |
| 765 int (*xDeviceCharacteristics)(sqlite3_file*); |
| 766 /* Methods above are valid for version 1 */ |
| 767 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); |
| 768 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); |
| 769 void (*xShmBarrier)(sqlite3_file*); |
| 770 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); |
| 771 /* Methods above are valid for version 2 */ |
| 772 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); |
| 773 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); |
| 774 /* Methods above are valid for version 3 */ |
| 775 /* Additional methods may be added in future releases */ |
| 776 }; |
| 777 |
| 778 /* |
| 779 ** CAPI3REF: Standard File Control Opcodes |
| 780 ** KEYWORDS: {file control opcodes} {file control opcode} |
| 781 ** |
| 782 ** These integer constants are opcodes for the xFileControl method |
| 783 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] |
| 784 ** interface. |
| 785 ** |
| 786 ** <ul> |
| 787 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] |
| 788 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This |
| 789 ** opcode causes the xFileControl method to write the current state of |
| 790 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], |
| 791 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) |
| 792 ** into an integer that the pArg argument points to. This capability |
| 793 ** is used during testing and is only available when the SQLITE_TEST |
| 794 ** compile-time option is used. |
| 795 ** |
| 796 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] |
| 797 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS |
| 798 ** layer a hint of how large the database file will grow to be during the |
| 799 ** current transaction. This hint is not guaranteed to be accurate but it |
| 800 ** is often close. The underlying VFS might choose to preallocate database |
| 801 ** file space based on this hint in order to help writes to the database |
| 802 ** file run faster. |
| 803 ** |
| 804 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] |
| 805 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS |
| 806 ** extends and truncates the database file in chunks of a size specified |
| 807 ** by the user. The fourth argument to [sqlite3_file_control()] should |
| 808 ** point to an integer (type int) containing the new chunk-size to use |
| 809 ** for the nominated database. Allocating database file space in large |
| 810 ** chunks (say 1MB at a time), may reduce file-system fragmentation and |
| 811 ** improve performance on some systems. |
| 812 ** |
| 813 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] |
| 814 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer |
| 815 ** to the [sqlite3_file] object associated with a particular database |
| 816 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. |
| 817 ** |
| 818 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] |
| 819 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer |
| 820 ** to the [sqlite3_file] object associated with the journal file (either |
| 821 ** the [rollback journal] or the [write-ahead log]) for a particular database |
| 822 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. |
| 823 ** |
| 824 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] |
| 825 ** No longer in use. |
| 826 ** |
| 827 ** <li>[[SQLITE_FCNTL_SYNC]] |
| 828 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and |
| 829 ** sent to the VFS immediately before the xSync method is invoked on a |
| 830 ** database file descriptor. Or, if the xSync method is not invoked |
| 831 ** because the user has configured SQLite with |
| 832 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place |
| 833 ** of the xSync method. In most cases, the pointer argument passed with |
| 834 ** this file-control is NULL. However, if the database file is being synced |
| 835 ** as part of a multi-database commit, the argument points to a nul-terminated |
| 836 ** string containing the transactions master-journal file name. VFSes that |
| 837 ** do not need this signal should silently ignore this opcode. Applications |
| 838 ** should not call [sqlite3_file_control()] with this opcode as doing so may |
| 839 ** disrupt the operation of the specialized VFSes that do require it. |
| 840 ** |
| 841 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] |
| 842 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite |
| 843 ** and sent to the VFS after a transaction has been committed immediately |
| 844 ** but before the database is unlocked. VFSes that do not need this signal |
| 845 ** should silently ignore this opcode. Applications should not call |
| 846 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the |
| 847 ** operation of the specialized VFSes that do require it. |
| 848 ** |
| 849 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] |
| 850 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic |
| 851 ** retry counts and intervals for certain disk I/O operations for the |
| 852 ** windows [VFS] in order to provide robustness in the presence of |
| 853 ** anti-virus programs. By default, the windows VFS will retry file read, |
| 854 ** file write, and file delete operations up to 10 times, with a delay |
| 855 ** of 25 milliseconds before the first retry and with the delay increasing |
| 856 ** by an additional 25 milliseconds with each subsequent retry. This |
| 857 ** opcode allows these two values (10 retries and 25 milliseconds of delay) |
| 858 ** to be adjusted. The values are changed for all database connections |
| 859 ** within the same process. The argument is a pointer to an array of two |
| 860 ** integers where the first integer i the new retry count and the second |
| 861 ** integer is the delay. If either integer is negative, then the setting |
| 862 ** is not changed but instead the prior value of that setting is written |
| 863 ** into the array entry, allowing the current retry settings to be |
| 864 ** interrogated. The zDbName parameter is ignored. |
| 865 ** |
| 866 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] |
| 867 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the |
| 868 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary |
| 869 ** write ahead log and shared memory files used for transaction control |
| 870 ** are automatically deleted when the latest connection to the database |
| 871 ** closes. Setting persistent WAL mode causes those files to persist after |
| 872 ** close. Persisting the files is useful when other processes that do not |
| 873 ** have write permission on the directory containing the database file want |
| 874 ** to read the database file, as the WAL and shared memory files must exist |
| 875 ** in order for the database to be readable. The fourth parameter to |
| 876 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. |
| 877 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent |
| 878 ** WAL mode. If the integer is -1, then it is overwritten with the current |
| 879 ** WAL persistence setting. |
| 880 ** |
| 881 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] |
| 882 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the |
| 883 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting |
| 884 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the |
| 885 ** xDeviceCharacteristics methods. The fourth parameter to |
| 886 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. |
| 887 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage |
| 888 ** mode. If the integer is -1, then it is overwritten with the current |
| 889 ** zero-damage mode setting. |
| 890 ** |
| 891 ** <li>[[SQLITE_FCNTL_OVERWRITE]] |
| 892 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening |
| 893 ** a write transaction to indicate that, unless it is rolled back for some |
| 894 ** reason, the entire database file will be overwritten by the current |
| 895 ** transaction. This is used by VACUUM operations. |
| 896 ** |
| 897 ** <li>[[SQLITE_FCNTL_VFSNAME]] |
| 898 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of |
| 899 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the |
| 900 ** final bottom-level VFS are written into memory obtained from |
| 901 ** [sqlite3_malloc()] and the result is stored in the char* variable |
| 902 ** that the fourth parameter of [sqlite3_file_control()] points to. |
| 903 ** The caller is responsible for freeing the memory when done. As with |
| 904 ** all file-control actions, there is no guarantee that this will actually |
| 905 ** do anything. Callers should initialize the char* variable to a NULL |
| 906 ** pointer in case this file-control is not implemented. This file-control |
| 907 ** is intended for diagnostic use only. |
| 908 ** |
| 909 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] |
| 910 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level |
| 911 ** [VFSes] currently in use. ^(The argument X in |
| 912 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be |
| 913 ** of type "[sqlite3_vfs] **". This opcodes will set *X |
| 914 ** to a pointer to the top-level VFS.)^ |
| 915 ** ^When there are multiple VFS shims in the stack, this opcode finds the |
| 916 ** upper-most shim only. |
| 917 ** |
| 918 ** <li>[[SQLITE_FCNTL_PRAGMA]] |
| 919 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] |
| 920 ** file control is sent to the open [sqlite3_file] object corresponding |
| 921 ** to the database file to which the pragma statement refers. ^The argument |
| 922 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of |
| 923 ** pointers to strings (char**) in which the second element of the array |
| 924 ** is the name of the pragma and the third element is the argument to the |
| 925 ** pragma or NULL if the pragma has no argument. ^The handler for an |
| 926 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element |
| 927 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] |
| 928 ** or the equivalent and that string will become the result of the pragma or |
| 929 ** the error message if the pragma fails. ^If the |
| 930 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal |
| 931 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] |
| 932 ** file control returns [SQLITE_OK], then the parser assumes that the |
| 933 ** VFS has handled the PRAGMA itself and the parser generates a no-op |
| 934 ** prepared statement if result string is NULL, or that returns a copy |
| 935 ** of the result string if the string is non-NULL. |
| 936 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns |
| 937 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means |
| 938 ** that the VFS encountered an error while handling the [PRAGMA] and the |
| 939 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] |
| 940 ** file control occurs at the beginning of pragma statement analysis and so |
| 941 ** it is able to override built-in [PRAGMA] statements. |
| 942 ** |
| 943 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] |
| 944 ** ^The [SQLITE_FCNTL_BUSYHANDLER] |
| 945 ** file-control may be invoked by SQLite on the database file handle |
| 946 ** shortly after it is opened in order to provide a custom VFS with access |
| 947 ** to the connections busy-handler callback. The argument is of type (void **) |
| 948 ** - an array of two (void *) values. The first (void *) actually points |
| 949 ** to a function of type (int (*)(void *)). In order to invoke the connections |
| 950 ** busy-handler, this function should be invoked with the second (void *) in |
| 951 ** the array as the only argument. If it returns non-zero, then the operation |
| 952 ** should be retried. If it returns zero, the custom VFS should abandon the |
| 953 ** current operation. |
| 954 ** |
| 955 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] |
| 956 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control |
| 957 ** to have SQLite generate a |
| 958 ** temporary filename using the same algorithm that is followed to generate |
| 959 ** temporary filenames for TEMP tables and other internal uses. The |
| 960 ** argument should be a char** which will be filled with the filename |
| 961 ** written into memory obtained from [sqlite3_malloc()]. The caller should |
| 962 ** invoke [sqlite3_free()] on the result to avoid a memory leak. |
| 963 ** |
| 964 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] |
| 965 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the |
| 966 ** maximum number of bytes that will be used for memory-mapped I/O. |
| 967 ** The argument is a pointer to a value of type sqlite3_int64 that |
| 968 ** is an advisory maximum number of bytes in the file to memory map. The |
| 969 ** pointer is overwritten with the old value. The limit is not changed if |
| 970 ** the value originally pointed to is negative, and so the current limit |
| 971 ** can be queried by passing in a pointer to a negative number. This |
| 972 ** file-control is used internally to implement [PRAGMA mmap_size]. |
| 973 ** |
| 974 ** <li>[[SQLITE_FCNTL_TRACE]] |
| 975 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information |
| 976 ** to the VFS about what the higher layers of the SQLite stack are doing. |
| 977 ** This file control is used by some VFS activity tracing [shims]. |
| 978 ** The argument is a zero-terminated string. Higher layers in the |
| 979 ** SQLite stack may generate instances of this file control if |
| 980 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. |
| 981 ** |
| 982 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] |
| 983 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a |
| 984 ** pointer to an integer and it writes a boolean into that integer depending |
| 985 ** on whether or not the file has been renamed, moved, or deleted since it |
| 986 ** was first opened. |
| 987 ** |
| 988 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] |
| 989 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the |
| 990 ** underlying native file handle associated with a file handle. This file |
| 991 ** control interprets its argument as a pointer to a native file handle and |
| 992 ** writes the resulting value there. |
| 993 ** |
| 994 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] |
| 995 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This |
| 996 ** opcode causes the xFileControl method to swap the file handle with the one |
| 997 ** pointed to by the pArg argument. This capability is used during testing |
| 998 ** and only needs to be supported when SQLITE_TEST is defined. |
| 999 ** |
| 1000 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] |
| 1001 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might |
| 1002 ** be advantageous to block on the next WAL lock if the lock is not immediately |
| 1003 ** available. The WAL subsystem issues this signal during rare |
| 1004 ** circumstances in order to fix a problem with priority inversion. |
| 1005 ** Applications should <em>not</em> use this file-control. |
| 1006 ** |
| 1007 ** <li>[[SQLITE_FCNTL_ZIPVFS]] |
| 1008 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other |
| 1009 ** VFS should return SQLITE_NOTFOUND for this opcode. |
| 1010 ** |
| 1011 ** <li>[[SQLITE_FCNTL_RBU]] |
| 1012 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by |
| 1013 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for |
| 1014 ** this opcode. |
| 1015 ** </ul> |
| 1016 */ |
| 1017 #define SQLITE_FCNTL_LOCKSTATE 1 |
| 1018 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 |
| 1019 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 |
| 1020 #define SQLITE_FCNTL_LAST_ERRNO 4 |
| 1021 #define SQLITE_FCNTL_SIZE_HINT 5 |
| 1022 #define SQLITE_FCNTL_CHUNK_SIZE 6 |
| 1023 #define SQLITE_FCNTL_FILE_POINTER 7 |
| 1024 #define SQLITE_FCNTL_SYNC_OMITTED 8 |
| 1025 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 |
| 1026 #define SQLITE_FCNTL_PERSIST_WAL 10 |
| 1027 #define SQLITE_FCNTL_OVERWRITE 11 |
| 1028 #define SQLITE_FCNTL_VFSNAME 12 |
| 1029 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 |
| 1030 #define SQLITE_FCNTL_PRAGMA 14 |
| 1031 #define SQLITE_FCNTL_BUSYHANDLER 15 |
| 1032 #define SQLITE_FCNTL_TEMPFILENAME 16 |
| 1033 #define SQLITE_FCNTL_MMAP_SIZE 18 |
| 1034 #define SQLITE_FCNTL_TRACE 19 |
| 1035 #define SQLITE_FCNTL_HAS_MOVED 20 |
| 1036 #define SQLITE_FCNTL_SYNC 21 |
| 1037 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 |
| 1038 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 |
| 1039 #define SQLITE_FCNTL_WAL_BLOCK 24 |
| 1040 #define SQLITE_FCNTL_ZIPVFS 25 |
| 1041 #define SQLITE_FCNTL_RBU 26 |
| 1042 #define SQLITE_FCNTL_VFS_POINTER 27 |
| 1043 #define SQLITE_FCNTL_JOURNAL_POINTER 28 |
| 1044 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 |
| 1045 #define SQLITE_FCNTL_PDB 30 |
| 1046 |
| 1047 /* deprecated names */ |
| 1048 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE |
| 1049 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE |
| 1050 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO |
| 1051 |
| 1052 |
| 1053 /* |
| 1054 ** CAPI3REF: Mutex Handle |
| 1055 ** |
| 1056 ** The mutex module within SQLite defines [sqlite3_mutex] to be an |
| 1057 ** abstract type for a mutex object. The SQLite core never looks |
| 1058 ** at the internal representation of an [sqlite3_mutex]. It only |
| 1059 ** deals with pointers to the [sqlite3_mutex] object. |
| 1060 ** |
| 1061 ** Mutexes are created using [sqlite3_mutex_alloc()]. |
| 1062 */ |
| 1063 typedef struct sqlite3_mutex sqlite3_mutex; |
| 1064 |
| 1065 /* |
| 1066 ** CAPI3REF: Loadable Extension Thunk |
| 1067 ** |
| 1068 ** A pointer to the opaque sqlite3_api_routines structure is passed as |
| 1069 ** the third parameter to entry points of [loadable extensions]. This |
| 1070 ** structure must be typedefed in order to work around compiler warnings |
| 1071 ** on some platforms. |
| 1072 */ |
| 1073 typedef struct sqlite3_api_routines sqlite3_api_routines; |
| 1074 |
| 1075 /* |
| 1076 ** CAPI3REF: OS Interface Object |
| 1077 ** |
| 1078 ** An instance of the sqlite3_vfs object defines the interface between |
| 1079 ** the SQLite core and the underlying operating system. The "vfs" |
| 1080 ** in the name of the object stands for "virtual file system". See |
| 1081 ** the [VFS | VFS documentation] for further information. |
| 1082 ** |
| 1083 ** The value of the iVersion field is initially 1 but may be larger in |
| 1084 ** future versions of SQLite. Additional fields may be appended to this |
| 1085 ** object when the iVersion value is increased. Note that the structure |
| 1086 ** of the sqlite3_vfs object changes in the transaction between |
| 1087 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not |
| 1088 ** modified. |
| 1089 ** |
| 1090 ** The szOsFile field is the size of the subclassed [sqlite3_file] |
| 1091 ** structure used by this VFS. mxPathname is the maximum length of |
| 1092 ** a pathname in this VFS. |
| 1093 ** |
| 1094 ** Registered sqlite3_vfs objects are kept on a linked list formed by |
| 1095 ** the pNext pointer. The [sqlite3_vfs_register()] |
| 1096 ** and [sqlite3_vfs_unregister()] interfaces manage this list |
| 1097 ** in a thread-safe way. The [sqlite3_vfs_find()] interface |
| 1098 ** searches the list. Neither the application code nor the VFS |
| 1099 ** implementation should use the pNext pointer. |
| 1100 ** |
| 1101 ** The pNext field is the only field in the sqlite3_vfs |
| 1102 ** structure that SQLite will ever modify. SQLite will only access |
| 1103 ** or modify this field while holding a particular static mutex. |
| 1104 ** The application should never modify anything within the sqlite3_vfs |
| 1105 ** object once the object has been registered. |
| 1106 ** |
| 1107 ** The zName field holds the name of the VFS module. The name must |
| 1108 ** be unique across all VFS modules. |
| 1109 ** |
| 1110 ** [[sqlite3_vfs.xOpen]] |
| 1111 ** ^SQLite guarantees that the zFilename parameter to xOpen |
| 1112 ** is either a NULL pointer or string obtained |
| 1113 ** from xFullPathname() with an optional suffix added. |
| 1114 ** ^If a suffix is added to the zFilename parameter, it will |
| 1115 ** consist of a single "-" character followed by no more than |
| 1116 ** 11 alphanumeric and/or "-" characters. |
| 1117 ** ^SQLite further guarantees that |
| 1118 ** the string will be valid and unchanged until xClose() is |
| 1119 ** called. Because of the previous sentence, |
| 1120 ** the [sqlite3_file] can safely store a pointer to the |
| 1121 ** filename if it needs to remember the filename for some reason. |
| 1122 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen |
| 1123 ** must invent its own temporary name for the file. ^Whenever the |
| 1124 ** xFilename parameter is NULL it will also be the case that the |
| 1125 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. |
| 1126 ** |
| 1127 ** The flags argument to xOpen() includes all bits set in |
| 1128 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] |
| 1129 ** or [sqlite3_open16()] is used, then flags includes at least |
| 1130 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. |
| 1131 ** If xOpen() opens a file read-only then it sets *pOutFlags to |
| 1132 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. |
| 1133 ** |
| 1134 ** ^(SQLite will also add one of the following flags to the xOpen() |
| 1135 ** call, depending on the object being opened: |
| 1136 ** |
| 1137 ** <ul> |
| 1138 ** <li> [SQLITE_OPEN_MAIN_DB] |
| 1139 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] |
| 1140 ** <li> [SQLITE_OPEN_TEMP_DB] |
| 1141 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] |
| 1142 ** <li> [SQLITE_OPEN_TRANSIENT_DB] |
| 1143 ** <li> [SQLITE_OPEN_SUBJOURNAL] |
| 1144 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] |
| 1145 ** <li> [SQLITE_OPEN_WAL] |
| 1146 ** </ul>)^ |
| 1147 ** |
| 1148 ** The file I/O implementation can use the object type flags to |
| 1149 ** change the way it deals with files. For example, an application |
| 1150 ** that does not care about crash recovery or rollback might make |
| 1151 ** the open of a journal file a no-op. Writes to this journal would |
| 1152 ** also be no-ops, and any attempt to read the journal would return |
| 1153 ** SQLITE_IOERR. Or the implementation might recognize that a database |
| 1154 ** file will be doing page-aligned sector reads and writes in a random |
| 1155 ** order and set up its I/O subsystem accordingly. |
| 1156 ** |
| 1157 ** SQLite might also add one of the following flags to the xOpen method: |
| 1158 ** |
| 1159 ** <ul> |
| 1160 ** <li> [SQLITE_OPEN_DELETEONCLOSE] |
| 1161 ** <li> [SQLITE_OPEN_EXCLUSIVE] |
| 1162 ** </ul> |
| 1163 ** |
| 1164 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be |
| 1165 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] |
| 1166 ** will be set for TEMP databases and their journals, transient |
| 1167 ** databases, and subjournals. |
| 1168 ** |
| 1169 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction |
| 1170 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly |
| 1171 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() |
| 1172 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the |
| 1173 ** SQLITE_OPEN_CREATE, is used to indicate that file should always |
| 1174 ** be created, and that it is an error if it already exists. |
| 1175 ** It is <i>not</i> used to indicate the file should be opened |
| 1176 ** for exclusive access. |
| 1177 ** |
| 1178 ** ^At least szOsFile bytes of memory are allocated by SQLite |
| 1179 ** to hold the [sqlite3_file] structure passed as the third |
| 1180 ** argument to xOpen. The xOpen method does not have to |
| 1181 ** allocate the structure; it should just fill it in. Note that |
| 1182 ** the xOpen method must set the sqlite3_file.pMethods to either |
| 1183 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do |
| 1184 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods |
| 1185 ** element will be valid after xOpen returns regardless of the success |
| 1186 ** or failure of the xOpen call. |
| 1187 ** |
| 1188 ** [[sqlite3_vfs.xAccess]] |
| 1189 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] |
| 1190 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to |
| 1191 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] |
| 1192 ** to test whether a file is at least readable. The file can be a |
| 1193 ** directory. |
| 1194 ** |
| 1195 ** ^SQLite will always allocate at least mxPathname+1 bytes for the |
| 1196 ** output buffer xFullPathname. The exact size of the output buffer |
| 1197 ** is also passed as a parameter to both methods. If the output buffer |
| 1198 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is |
| 1199 ** handled as a fatal error by SQLite, vfs implementations should endeavor |
| 1200 ** to prevent this by setting mxPathname to a sufficiently large value. |
| 1201 ** |
| 1202 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() |
| 1203 ** interfaces are not strictly a part of the filesystem, but they are |
| 1204 ** included in the VFS structure for completeness. |
| 1205 ** The xRandomness() function attempts to return nBytes bytes |
| 1206 ** of good-quality randomness into zOut. The return value is |
| 1207 ** the actual number of bytes of randomness obtained. |
| 1208 ** The xSleep() method causes the calling thread to sleep for at |
| 1209 ** least the number of microseconds given. ^The xCurrentTime() |
| 1210 ** method returns a Julian Day Number for the current date and time as |
| 1211 ** a floating point value. |
| 1212 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian |
| 1213 ** Day Number multiplied by 86400000 (the number of milliseconds in |
| 1214 ** a 24-hour day). |
| 1215 ** ^SQLite will use the xCurrentTimeInt64() method to get the current |
| 1216 ** date and time if that method is available (if iVersion is 2 or |
| 1217 ** greater and the function pointer is not NULL) and will fall back |
| 1218 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. |
| 1219 ** |
| 1220 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces |
| 1221 ** are not used by the SQLite core. These optional interfaces are provided |
| 1222 ** by some VFSes to facilitate testing of the VFS code. By overriding |
| 1223 ** system calls with functions under its control, a test program can |
| 1224 ** simulate faults and error conditions that would otherwise be difficult |
| 1225 ** or impossible to induce. The set of system calls that can be overridden |
| 1226 ** varies from one VFS to another, and from one version of the same VFS to the |
| 1227 ** next. Applications that use these interfaces must be prepared for any |
| 1228 ** or all of these interfaces to be NULL or for their behavior to change |
| 1229 ** from one release to the next. Applications must not attempt to access |
| 1230 ** any of these methods if the iVersion of the VFS is less than 3. |
| 1231 */ |
| 1232 typedef struct sqlite3_vfs sqlite3_vfs; |
| 1233 typedef void (*sqlite3_syscall_ptr)(void); |
| 1234 struct sqlite3_vfs { |
| 1235 int iVersion; /* Structure version number (currently 3) */ |
| 1236 int szOsFile; /* Size of subclassed sqlite3_file */ |
| 1237 int mxPathname; /* Maximum file pathname length */ |
| 1238 sqlite3_vfs *pNext; /* Next registered VFS */ |
| 1239 const char *zName; /* Name of this virtual file system */ |
| 1240 void *pAppData; /* Pointer to application-specific data */ |
| 1241 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, |
| 1242 int flags, int *pOutFlags); |
| 1243 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); |
| 1244 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); |
| 1245 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); |
| 1246 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); |
| 1247 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); |
| 1248 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); |
| 1249 void (*xDlClose)(sqlite3_vfs*, void*); |
| 1250 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); |
| 1251 int (*xSleep)(sqlite3_vfs*, int microseconds); |
| 1252 int (*xCurrentTime)(sqlite3_vfs*, double*); |
| 1253 int (*xGetLastError)(sqlite3_vfs*, int, char *); |
| 1254 /* |
| 1255 ** The methods above are in version 1 of the sqlite_vfs object |
| 1256 ** definition. Those that follow are added in version 2 or later |
| 1257 */ |
| 1258 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); |
| 1259 /* |
| 1260 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. |
| 1261 ** Those below are for version 3 and greater. |
| 1262 */ |
| 1263 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); |
| 1264 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); |
| 1265 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); |
| 1266 /* |
| 1267 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. |
| 1268 ** New fields may be appended in future versions. The iVersion |
| 1269 ** value will increment whenever this happens. |
| 1270 */ |
| 1271 }; |
| 1272 |
| 1273 /* |
| 1274 ** CAPI3REF: Flags for the xAccess VFS method |
| 1275 ** |
| 1276 ** These integer constants can be used as the third parameter to |
| 1277 ** the xAccess method of an [sqlite3_vfs] object. They determine |
| 1278 ** what kind of permissions the xAccess method is looking for. |
| 1279 ** With SQLITE_ACCESS_EXISTS, the xAccess method |
| 1280 ** simply checks whether the file exists. |
| 1281 ** With SQLITE_ACCESS_READWRITE, the xAccess method |
| 1282 ** checks whether the named directory is both readable and writable |
| 1283 ** (in other words, if files can be added, removed, and renamed within |
| 1284 ** the directory). |
| 1285 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the |
| 1286 ** [temp_store_directory pragma], though this could change in a future |
| 1287 ** release of SQLite. |
| 1288 ** With SQLITE_ACCESS_READ, the xAccess method |
| 1289 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is |
| 1290 ** currently unused, though it might be used in a future release of |
| 1291 ** SQLite. |
| 1292 */ |
| 1293 #define SQLITE_ACCESS_EXISTS 0 |
| 1294 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ |
| 1295 #define SQLITE_ACCESS_READ 2 /* Unused */ |
| 1296 |
| 1297 /* |
| 1298 ** CAPI3REF: Flags for the xShmLock VFS method |
| 1299 ** |
| 1300 ** These integer constants define the various locking operations |
| 1301 ** allowed by the xShmLock method of [sqlite3_io_methods]. The |
| 1302 ** following are the only legal combinations of flags to the |
| 1303 ** xShmLock method: |
| 1304 ** |
| 1305 ** <ul> |
| 1306 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED |
| 1307 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE |
| 1308 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED |
| 1309 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE |
| 1310 ** </ul> |
| 1311 ** |
| 1312 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as |
| 1313 ** was given on the corresponding lock. |
| 1314 ** |
| 1315 ** The xShmLock method can transition between unlocked and SHARED or |
| 1316 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED |
| 1317 ** and EXCLUSIVE. |
| 1318 */ |
| 1319 #define SQLITE_SHM_UNLOCK 1 |
| 1320 #define SQLITE_SHM_LOCK 2 |
| 1321 #define SQLITE_SHM_SHARED 4 |
| 1322 #define SQLITE_SHM_EXCLUSIVE 8 |
| 1323 |
| 1324 /* |
| 1325 ** CAPI3REF: Maximum xShmLock index |
| 1326 ** |
| 1327 ** The xShmLock method on [sqlite3_io_methods] may use values |
| 1328 ** between 0 and this upper bound as its "offset" argument. |
| 1329 ** The SQLite core will never attempt to acquire or release a |
| 1330 ** lock outside of this range |
| 1331 */ |
| 1332 #define SQLITE_SHM_NLOCK 8 |
| 1333 |
| 1334 |
| 1335 /* |
| 1336 ** CAPI3REF: Initialize The SQLite Library |
| 1337 ** |
| 1338 ** ^The sqlite3_initialize() routine initializes the |
| 1339 ** SQLite library. ^The sqlite3_shutdown() routine |
| 1340 ** deallocates any resources that were allocated by sqlite3_initialize(). |
| 1341 ** These routines are designed to aid in process initialization and |
| 1342 ** shutdown on embedded systems. Workstation applications using |
| 1343 ** SQLite normally do not need to invoke either of these routines. |
| 1344 ** |
| 1345 ** A call to sqlite3_initialize() is an "effective" call if it is |
| 1346 ** the first time sqlite3_initialize() is invoked during the lifetime of |
| 1347 ** the process, or if it is the first time sqlite3_initialize() is invoked |
| 1348 ** following a call to sqlite3_shutdown(). ^(Only an effective call |
| 1349 ** of sqlite3_initialize() does any initialization. All other calls |
| 1350 ** are harmless no-ops.)^ |
| 1351 ** |
| 1352 ** A call to sqlite3_shutdown() is an "effective" call if it is the first |
| 1353 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only |
| 1354 ** an effective call to sqlite3_shutdown() does any deinitialization. |
| 1355 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ |
| 1356 ** |
| 1357 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() |
| 1358 ** is not. The sqlite3_shutdown() interface must only be called from a |
| 1359 ** single thread. All open [database connections] must be closed and all |
| 1360 ** other SQLite resources must be deallocated prior to invoking |
| 1361 ** sqlite3_shutdown(). |
| 1362 ** |
| 1363 ** Among other things, ^sqlite3_initialize() will invoke |
| 1364 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() |
| 1365 ** will invoke sqlite3_os_end(). |
| 1366 ** |
| 1367 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. |
| 1368 ** ^If for some reason, sqlite3_initialize() is unable to initialize |
| 1369 ** the library (perhaps it is unable to allocate a needed resource such |
| 1370 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. |
| 1371 ** |
| 1372 ** ^The sqlite3_initialize() routine is called internally by many other |
| 1373 ** SQLite interfaces so that an application usually does not need to |
| 1374 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] |
| 1375 ** calls sqlite3_initialize() so the SQLite library will be automatically |
| 1376 ** initialized when [sqlite3_open()] is called if it has not be initialized |
| 1377 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] |
| 1378 ** compile-time option, then the automatic calls to sqlite3_initialize() |
| 1379 ** are omitted and the application must call sqlite3_initialize() directly |
| 1380 ** prior to using any other SQLite interface. For maximum portability, |
| 1381 ** it is recommended that applications always invoke sqlite3_initialize() |
| 1382 ** directly prior to using any other SQLite interface. Future releases |
| 1383 ** of SQLite may require this. In other words, the behavior exhibited |
| 1384 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the |
| 1385 ** default behavior in some future release of SQLite. |
| 1386 ** |
| 1387 ** The sqlite3_os_init() routine does operating-system specific |
| 1388 ** initialization of the SQLite library. The sqlite3_os_end() |
| 1389 ** routine undoes the effect of sqlite3_os_init(). Typical tasks |
| 1390 ** performed by these routines include allocation or deallocation |
| 1391 ** of static resources, initialization of global variables, |
| 1392 ** setting up a default [sqlite3_vfs] module, or setting up |
| 1393 ** a default configuration using [sqlite3_config()]. |
| 1394 ** |
| 1395 ** The application should never invoke either sqlite3_os_init() |
| 1396 ** or sqlite3_os_end() directly. The application should only invoke |
| 1397 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() |
| 1398 ** interface is called automatically by sqlite3_initialize() and |
| 1399 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate |
| 1400 ** implementations for sqlite3_os_init() and sqlite3_os_end() |
| 1401 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. |
| 1402 ** When [custom builds | built for other platforms] |
| 1403 ** (using the [SQLITE_OS_OTHER=1] compile-time |
| 1404 ** option) the application must supply a suitable implementation for |
| 1405 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied |
| 1406 ** implementation of sqlite3_os_init() or sqlite3_os_end() |
| 1407 ** must return [SQLITE_OK] on success and some other [error code] upon |
| 1408 ** failure. |
| 1409 */ |
| 1410 int sqlite3_initialize(void); |
| 1411 int sqlite3_shutdown(void); |
| 1412 int sqlite3_os_init(void); |
| 1413 int sqlite3_os_end(void); |
| 1414 |
| 1415 /* |
| 1416 ** CAPI3REF: Configuring The SQLite Library |
| 1417 ** |
| 1418 ** The sqlite3_config() interface is used to make global configuration |
| 1419 ** changes to SQLite in order to tune SQLite to the specific needs of |
| 1420 ** the application. The default configuration is recommended for most |
| 1421 ** applications and so this routine is usually not necessary. It is |
| 1422 ** provided to support rare applications with unusual needs. |
| 1423 ** |
| 1424 ** <b>The sqlite3_config() interface is not threadsafe. The application |
| 1425 ** must ensure that no other SQLite interfaces are invoked by other |
| 1426 ** threads while sqlite3_config() is running.</b> |
| 1427 ** |
| 1428 ** The sqlite3_config() interface |
| 1429 ** may only be invoked prior to library initialization using |
| 1430 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. |
| 1431 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before |
| 1432 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. |
| 1433 ** Note, however, that ^sqlite3_config() can be called as part of the |
| 1434 ** implementation of an application-defined [sqlite3_os_init()]. |
| 1435 ** |
| 1436 ** The first argument to sqlite3_config() is an integer |
| 1437 ** [configuration option] that determines |
| 1438 ** what property of SQLite is to be configured. Subsequent arguments |
| 1439 ** vary depending on the [configuration option] |
| 1440 ** in the first argument. |
| 1441 ** |
| 1442 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. |
| 1443 ** ^If the option is unknown or SQLite is unable to set the option |
| 1444 ** then this routine returns a non-zero [error code]. |
| 1445 */ |
| 1446 int sqlite3_config(int, ...); |
| 1447 |
| 1448 /* |
| 1449 ** CAPI3REF: Configure database connections |
| 1450 ** METHOD: sqlite3 |
| 1451 ** |
| 1452 ** The sqlite3_db_config() interface is used to make configuration |
| 1453 ** changes to a [database connection]. The interface is similar to |
| 1454 ** [sqlite3_config()] except that the changes apply to a single |
| 1455 ** [database connection] (specified in the first argument). |
| 1456 ** |
| 1457 ** The second argument to sqlite3_db_config(D,V,...) is the |
| 1458 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code |
| 1459 ** that indicates what aspect of the [database connection] is being configured. |
| 1460 ** Subsequent arguments vary depending on the configuration verb. |
| 1461 ** |
| 1462 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if |
| 1463 ** the call is considered successful. |
| 1464 */ |
| 1465 int sqlite3_db_config(sqlite3*, int op, ...); |
| 1466 |
| 1467 /* |
| 1468 ** CAPI3REF: Memory Allocation Routines |
| 1469 ** |
| 1470 ** An instance of this object defines the interface between SQLite |
| 1471 ** and low-level memory allocation routines. |
| 1472 ** |
| 1473 ** This object is used in only one place in the SQLite interface. |
| 1474 ** A pointer to an instance of this object is the argument to |
| 1475 ** [sqlite3_config()] when the configuration option is |
| 1476 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. |
| 1477 ** By creating an instance of this object |
| 1478 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) |
| 1479 ** during configuration, an application can specify an alternative |
| 1480 ** memory allocation subsystem for SQLite to use for all of its |
| 1481 ** dynamic memory needs. |
| 1482 ** |
| 1483 ** Note that SQLite comes with several [built-in memory allocators] |
| 1484 ** that are perfectly adequate for the overwhelming majority of applications |
| 1485 ** and that this object is only useful to a tiny minority of applications |
| 1486 ** with specialized memory allocation requirements. This object is |
| 1487 ** also used during testing of SQLite in order to specify an alternative |
| 1488 ** memory allocator that simulates memory out-of-memory conditions in |
| 1489 ** order to verify that SQLite recovers gracefully from such |
| 1490 ** conditions. |
| 1491 ** |
| 1492 ** The xMalloc, xRealloc, and xFree methods must work like the |
| 1493 ** malloc(), realloc() and free() functions from the standard C library. |
| 1494 ** ^SQLite guarantees that the second argument to |
| 1495 ** xRealloc is always a value returned by a prior call to xRoundup. |
| 1496 ** |
| 1497 ** xSize should return the allocated size of a memory allocation |
| 1498 ** previously obtained from xMalloc or xRealloc. The allocated size |
| 1499 ** is always at least as big as the requested size but may be larger. |
| 1500 ** |
| 1501 ** The xRoundup method returns what would be the allocated size of |
| 1502 ** a memory allocation given a particular requested size. Most memory |
| 1503 ** allocators round up memory allocations at least to the next multiple |
| 1504 ** of 8. Some allocators round up to a larger multiple or to a power of 2. |
| 1505 ** Every memory allocation request coming in through [sqlite3_malloc()] |
| 1506 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, |
| 1507 ** that causes the corresponding memory allocation to fail. |
| 1508 ** |
| 1509 ** The xInit method initializes the memory allocator. For example, |
| 1510 ** it might allocate any require mutexes or initialize internal data |
| 1511 ** structures. The xShutdown method is invoked (indirectly) by |
| 1512 ** [sqlite3_shutdown()] and should deallocate any resources acquired |
| 1513 ** by xInit. The pAppData pointer is used as the only parameter to |
| 1514 ** xInit and xShutdown. |
| 1515 ** |
| 1516 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes |
| 1517 ** the xInit method, so the xInit method need not be threadsafe. The |
| 1518 ** xShutdown method is only called from [sqlite3_shutdown()] so it does |
| 1519 ** not need to be threadsafe either. For all other methods, SQLite |
| 1520 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the |
| 1521 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which |
| 1522 ** it is by default) and so the methods are automatically serialized. |
| 1523 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other |
| 1524 ** methods must be threadsafe or else make their own arrangements for |
| 1525 ** serialization. |
| 1526 ** |
| 1527 ** SQLite will never invoke xInit() more than once without an intervening |
| 1528 ** call to xShutdown(). |
| 1529 */ |
| 1530 typedef struct sqlite3_mem_methods sqlite3_mem_methods; |
| 1531 struct sqlite3_mem_methods { |
| 1532 void *(*xMalloc)(int); /* Memory allocation function */ |
| 1533 void (*xFree)(void*); /* Free a prior allocation */ |
| 1534 void *(*xRealloc)(void*,int); /* Resize an allocation */ |
| 1535 int (*xSize)(void*); /* Return the size of an allocation */ |
| 1536 int (*xRoundup)(int); /* Round up request size to allocation size */ |
| 1537 int (*xInit)(void*); /* Initialize the memory allocator */ |
| 1538 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ |
| 1539 void *pAppData; /* Argument to xInit() and xShutdown() */ |
| 1540 }; |
| 1541 |
| 1542 /* |
| 1543 ** CAPI3REF: Configuration Options |
| 1544 ** KEYWORDS: {configuration option} |
| 1545 ** |
| 1546 ** These constants are the available integer configuration options that |
| 1547 ** can be passed as the first argument to the [sqlite3_config()] interface. |
| 1548 ** |
| 1549 ** New configuration options may be added in future releases of SQLite. |
| 1550 ** Existing configuration options might be discontinued. Applications |
| 1551 ** should check the return code from [sqlite3_config()] to make sure that |
| 1552 ** the call worked. The [sqlite3_config()] interface will return a |
| 1553 ** non-zero [error code] if a discontinued or unsupported configuration option |
| 1554 ** is invoked. |
| 1555 ** |
| 1556 ** <dl> |
| 1557 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> |
| 1558 ** <dd>There are no arguments to this option. ^This option sets the |
| 1559 ** [threading mode] to Single-thread. In other words, it disables |
| 1560 ** all mutexing and puts SQLite into a mode where it can only be used |
| 1561 ** by a single thread. ^If SQLite is compiled with |
| 1562 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
| 1563 ** it is not possible to change the [threading mode] from its default |
| 1564 ** value of Single-thread and so [sqlite3_config()] will return |
| 1565 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD |
| 1566 ** configuration option.</dd> |
| 1567 ** |
| 1568 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> |
| 1569 ** <dd>There are no arguments to this option. ^This option sets the |
| 1570 ** [threading mode] to Multi-thread. In other words, it disables |
| 1571 ** mutexing on [database connection] and [prepared statement] objects. |
| 1572 ** The application is responsible for serializing access to |
| 1573 ** [database connections] and [prepared statements]. But other mutexes |
| 1574 ** are enabled so that SQLite will be safe to use in a multi-threaded |
| 1575 ** environment as long as no two threads attempt to use the same |
| 1576 ** [database connection] at the same time. ^If SQLite is compiled with |
| 1577 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
| 1578 ** it is not possible to set the Multi-thread [threading mode] and |
| 1579 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the |
| 1580 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> |
| 1581 ** |
| 1582 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> |
| 1583 ** <dd>There are no arguments to this option. ^This option sets the |
| 1584 ** [threading mode] to Serialized. In other words, this option enables |
| 1585 ** all mutexes including the recursive |
| 1586 ** mutexes on [database connection] and [prepared statement] objects. |
| 1587 ** In this mode (which is the default when SQLite is compiled with |
| 1588 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access |
| 1589 ** to [database connections] and [prepared statements] so that the |
| 1590 ** application is free to use the same [database connection] or the |
| 1591 ** same [prepared statement] in different threads at the same time. |
| 1592 ** ^If SQLite is compiled with |
| 1593 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
| 1594 ** it is not possible to set the Serialized [threading mode] and |
| 1595 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the |
| 1596 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> |
| 1597 ** |
| 1598 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> |
| 1599 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is |
| 1600 ** a pointer to an instance of the [sqlite3_mem_methods] structure. |
| 1601 ** The argument specifies |
| 1602 ** alternative low-level memory allocation routines to be used in place of |
| 1603 ** the memory allocation routines built into SQLite.)^ ^SQLite makes |
| 1604 ** its own private copy of the content of the [sqlite3_mem_methods] structure |
| 1605 ** before the [sqlite3_config()] call returns.</dd> |
| 1606 ** |
| 1607 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> |
| 1608 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which |
| 1609 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. |
| 1610 ** The [sqlite3_mem_methods] |
| 1611 ** structure is filled with the currently defined memory allocation routines.)^ |
| 1612 ** This option can be used to overload the default memory allocation |
| 1613 ** routines with a wrapper that simulations memory allocation failure or |
| 1614 ** tracks memory usage, for example. </dd> |
| 1615 ** |
| 1616 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> |
| 1617 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, |
| 1618 ** interpreted as a boolean, which enables or disables the collection of |
| 1619 ** memory allocation statistics. ^(When memory allocation statistics are |
| 1620 ** disabled, the following SQLite interfaces become non-operational: |
| 1621 ** <ul> |
| 1622 ** <li> [sqlite3_memory_used()] |
| 1623 ** <li> [sqlite3_memory_highwater()] |
| 1624 ** <li> [sqlite3_soft_heap_limit64()] |
| 1625 ** <li> [sqlite3_status64()] |
| 1626 ** </ul>)^ |
| 1627 ** ^Memory allocation statistics are enabled by default unless SQLite is |
| 1628 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory |
| 1629 ** allocation statistics are disabled by default. |
| 1630 ** </dd> |
| 1631 ** |
| 1632 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> |
| 1633 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer |
| 1634 ** that SQLite can use for scratch memory. ^(There are three arguments |
| 1635 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte |
| 1636 ** aligned memory buffer from which the scratch allocations will be |
| 1637 ** drawn, the size of each scratch allocation (sz), |
| 1638 ** and the maximum number of scratch allocations (N).)^ |
| 1639 ** The first argument must be a pointer to an 8-byte aligned buffer |
| 1640 ** of at least sz*N bytes of memory. |
| 1641 ** ^SQLite will not use more than one scratch buffers per thread. |
| 1642 ** ^SQLite will never request a scratch buffer that is more than 6 |
| 1643 ** times the database page size. |
| 1644 ** ^If SQLite needs needs additional |
| 1645 ** scratch memory beyond what is provided by this configuration option, then |
| 1646 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p> |
| 1647 ** ^When the application provides any amount of scratch memory using |
| 1648 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large |
| 1649 ** [sqlite3_malloc|heap allocations]. |
| 1650 ** This can help [Robson proof|prevent memory allocation failures] due to heap |
| 1651 ** fragmentation in low-memory embedded systems. |
| 1652 ** </dd> |
| 1653 ** |
| 1654 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> |
| 1655 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool |
| 1656 ** that SQLite can use for the database page cache with the default page |
| 1657 ** cache implementation. |
| 1658 ** This configuration option is a no-op if an application-define page |
| 1659 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. |
| 1660 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to |
| 1661 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), |
| 1662 ** and the number of cache lines (N). |
| 1663 ** The sz argument should be the size of the largest database page |
| 1664 ** (a power of two between 512 and 65536) plus some extra bytes for each |
| 1665 ** page header. ^The number of extra bytes needed by the page header |
| 1666 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. |
| 1667 ** ^It is harmless, apart from the wasted memory, |
| 1668 ** for the sz parameter to be larger than necessary. The pMem |
| 1669 ** argument must be either a NULL pointer or a pointer to an 8-byte |
| 1670 ** aligned block of memory of at least sz*N bytes, otherwise |
| 1671 ** subsequent behavior is undefined. |
| 1672 ** ^When pMem is not NULL, SQLite will strive to use the memory provided |
| 1673 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if |
| 1674 ** a page cache line is larger than sz bytes or if all of the pMem buffer |
| 1675 ** is exhausted. |
| 1676 ** ^If pMem is NULL and N is non-zero, then each database connection |
| 1677 ** does an initial bulk allocation for page cache memory |
| 1678 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or |
| 1679 ** of -1024*N bytes if N is negative, . ^If additional |
| 1680 ** page cache memory is needed beyond what is provided by the initial |
| 1681 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each |
| 1682 ** additional cache line. </dd> |
| 1683 ** |
| 1684 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> |
| 1685 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer |
| 1686 ** that SQLite will use for all of its dynamic memory allocation needs |
| 1687 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and |
| 1688 ** [SQLITE_CONFIG_PAGECACHE]. |
| 1689 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled |
| 1690 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns |
| 1691 ** [SQLITE_ERROR] if invoked otherwise. |
| 1692 ** ^There are three arguments to SQLITE_CONFIG_HEAP: |
| 1693 ** An 8-byte aligned pointer to the memory, |
| 1694 ** the number of bytes in the memory buffer, and the minimum allocation size. |
| 1695 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts |
| 1696 ** to using its default memory allocator (the system malloc() implementation), |
| 1697 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the |
| 1698 ** memory pointer is not NULL then the alternative memory |
| 1699 ** allocator is engaged to handle all of SQLites memory allocation needs. |
| 1700 ** The first pointer (the memory pointer) must be aligned to an 8-byte |
| 1701 ** boundary or subsequent behavior of SQLite will be undefined. |
| 1702 ** The minimum allocation size is capped at 2**12. Reasonable values |
| 1703 ** for the minimum allocation size are 2**5 through 2**8.</dd> |
| 1704 ** |
| 1705 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> |
| 1706 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a |
| 1707 ** pointer to an instance of the [sqlite3_mutex_methods] structure. |
| 1708 ** The argument specifies alternative low-level mutex routines to be used |
| 1709 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of |
| 1710 ** the content of the [sqlite3_mutex_methods] structure before the call to |
| 1711 ** [sqlite3_config()] returns. ^If SQLite is compiled with |
| 1712 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
| 1713 ** the entire mutexing subsystem is omitted from the build and hence calls to |
| 1714 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will |
| 1715 ** return [SQLITE_ERROR].</dd> |
| 1716 ** |
| 1717 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> |
| 1718 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which |
| 1719 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The |
| 1720 ** [sqlite3_mutex_methods] |
| 1721 ** structure is filled with the currently defined mutex routines.)^ |
| 1722 ** This option can be used to overload the default mutex allocation |
| 1723 ** routines with a wrapper used to track mutex usage for performance |
| 1724 ** profiling or testing, for example. ^If SQLite is compiled with |
| 1725 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
| 1726 ** the entire mutexing subsystem is omitted from the build and hence calls to |
| 1727 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will |
| 1728 ** return [SQLITE_ERROR].</dd> |
| 1729 ** |
| 1730 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> |
| 1731 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine |
| 1732 ** the default size of lookaside memory on each [database connection]. |
| 1733 ** The first argument is the |
| 1734 ** size of each lookaside buffer slot and the second is the number of |
| 1735 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE |
| 1736 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] |
| 1737 ** option to [sqlite3_db_config()] can be used to change the lookaside |
| 1738 ** configuration on individual connections.)^ </dd> |
| 1739 ** |
| 1740 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> |
| 1741 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is |
| 1742 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies |
| 1743 ** the interface to a custom page cache implementation.)^ |
| 1744 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> |
| 1745 ** |
| 1746 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> |
| 1747 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which |
| 1748 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of |
| 1749 ** the current page cache implementation into that object.)^ </dd> |
| 1750 ** |
| 1751 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> |
| 1752 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite |
| 1753 ** global [error log]. |
| 1754 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a |
| 1755 ** function with a call signature of void(*)(void*,int,const char*), |
| 1756 ** and a pointer to void. ^If the function pointer is not NULL, it is |
| 1757 ** invoked by [sqlite3_log()] to process each logging event. ^If the |
| 1758 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. |
| 1759 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is |
| 1760 ** passed through as the first parameter to the application-defined logger |
| 1761 ** function whenever that function is invoked. ^The second parameter to |
| 1762 ** the logger function is a copy of the first parameter to the corresponding |
| 1763 ** [sqlite3_log()] call and is intended to be a [result code] or an |
| 1764 ** [extended result code]. ^The third parameter passed to the logger is |
| 1765 ** log message after formatting via [sqlite3_snprintf()]. |
| 1766 ** The SQLite logging interface is not reentrant; the logger function |
| 1767 ** supplied by the application must not invoke any SQLite interface. |
| 1768 ** In a multi-threaded application, the application-defined logger |
| 1769 ** function must be threadsafe. </dd> |
| 1770 ** |
| 1771 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI |
| 1772 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. |
| 1773 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, |
| 1774 ** then URI handling is globally disabled.)^ ^If URI handling is globally |
| 1775 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], |
| 1776 ** [sqlite3_open16()] or |
| 1777 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless |
| 1778 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database |
| 1779 ** connection is opened. ^If it is globally disabled, filenames are |
| 1780 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the |
| 1781 ** database connection is opened. ^(By default, URI handling is globally |
| 1782 ** disabled. The default value may be changed by compiling with the |
| 1783 ** [SQLITE_USE_URI] symbol defined.)^ |
| 1784 ** |
| 1785 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN |
| 1786 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer |
| 1787 ** argument which is interpreted as a boolean in order to enable or disable |
| 1788 ** the use of covering indices for full table scans in the query optimizer. |
| 1789 ** ^The default setting is determined |
| 1790 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" |
| 1791 ** if that compile-time option is omitted. |
| 1792 ** The ability to disable the use of covering indices for full table scans |
| 1793 ** is because some incorrectly coded legacy applications might malfunction |
| 1794 ** when the optimization is enabled. Providing the ability to |
| 1795 ** disable the optimization allows the older, buggy application code to work |
| 1796 ** without change even with newer versions of SQLite. |
| 1797 ** |
| 1798 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] |
| 1799 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE |
| 1800 ** <dd> These options are obsolete and should not be used by new code. |
| 1801 ** They are retained for backwards compatibility but are now no-ops. |
| 1802 ** </dd> |
| 1803 ** |
| 1804 ** [[SQLITE_CONFIG_SQLLOG]] |
| 1805 ** <dt>SQLITE_CONFIG_SQLLOG |
| 1806 ** <dd>This option is only available if sqlite is compiled with the |
| 1807 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should |
| 1808 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). |
| 1809 ** The second should be of type (void*). The callback is invoked by the library |
| 1810 ** in three separate circumstances, identified by the value passed as the |
| 1811 ** fourth parameter. If the fourth parameter is 0, then the database connection |
| 1812 ** passed as the second argument has just been opened. The third argument |
| 1813 ** points to a buffer containing the name of the main database file. If the |
| 1814 ** fourth parameter is 1, then the SQL statement that the third parameter |
| 1815 ** points to has just been executed. Or, if the fourth parameter is 2, then |
| 1816 ** the connection being passed as the second parameter is being closed. The |
| 1817 ** third parameter is passed NULL In this case. An example of using this |
| 1818 ** configuration option can be seen in the "test_sqllog.c" source file in |
| 1819 ** the canonical SQLite source tree.</dd> |
| 1820 ** |
| 1821 ** [[SQLITE_CONFIG_MMAP_SIZE]] |
| 1822 ** <dt>SQLITE_CONFIG_MMAP_SIZE |
| 1823 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values |
| 1824 ** that are the default mmap size limit (the default setting for |
| 1825 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. |
| 1826 ** ^The default setting can be overridden by each database connection using |
| 1827 ** either the [PRAGMA mmap_size] command, or by using the |
| 1828 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size |
| 1829 ** will be silently truncated if necessary so that it does not exceed the |
| 1830 ** compile-time maximum mmap size set by the |
| 1831 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ |
| 1832 ** ^If either argument to this option is negative, then that argument is |
| 1833 ** changed to its compile-time default. |
| 1834 ** |
| 1835 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] |
| 1836 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE |
| 1837 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is |
| 1838 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro |
| 1839 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value |
| 1840 ** that specifies the maximum size of the created heap. |
| 1841 ** |
| 1842 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] |
| 1843 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ |
| 1844 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which |
| 1845 ** is a pointer to an integer and writes into that integer the number of extra |
| 1846 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. |
| 1847 ** The amount of extra space required can change depending on the compiler, |
| 1848 ** target platform, and SQLite version. |
| 1849 ** |
| 1850 ** [[SQLITE_CONFIG_PMASZ]] |
| 1851 ** <dt>SQLITE_CONFIG_PMASZ |
| 1852 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which |
| 1853 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded |
| 1854 ** sorter to that integer. The default minimum PMA Size is set by the |
| 1855 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched |
| 1856 ** to help with sort operations when multithreaded sorting |
| 1857 ** is enabled (using the [PRAGMA threads] command) and the amount of content |
| 1858 ** to be sorted exceeds the page size times the minimum of the |
| 1859 ** [PRAGMA cache_size] setting and this value. |
| 1860 ** |
| 1861 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] |
| 1862 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL |
| 1863 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which |
| 1864 ** becomes the [statement journal] spill-to-disk threshold. |
| 1865 ** [Statement journals] are held in memory until their size (in bytes) |
| 1866 ** exceeds this threshold, at which point they are written to disk. |
| 1867 ** Or if the threshold is -1, statement journals are always held |
| 1868 ** exclusively in memory. |
| 1869 ** Since many statement journals never become large, setting the spill |
| 1870 ** threshold to a value such as 64KiB can greatly reduce the amount of |
| 1871 ** I/O required to support statement rollback. |
| 1872 ** The default value for this setting is controlled by the |
| 1873 ** [SQLITE_STMTJRNL_SPILL] compile-time option. |
| 1874 ** </dl> |
| 1875 */ |
| 1876 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ |
| 1877 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ |
| 1878 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ |
| 1879 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ |
| 1880 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ |
| 1881 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ |
| 1882 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ |
| 1883 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ |
| 1884 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ |
| 1885 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ |
| 1886 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ |
| 1887 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ |
| 1888 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ |
| 1889 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ |
| 1890 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ |
| 1891 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ |
| 1892 #define SQLITE_CONFIG_URI 17 /* int */ |
| 1893 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ |
| 1894 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ |
| 1895 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ |
| 1896 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ |
| 1897 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ |
| 1898 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ |
| 1899 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ |
| 1900 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ |
| 1901 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ |
| 1902 |
| 1903 /* |
| 1904 ** CAPI3REF: Database Connection Configuration Options |
| 1905 ** |
| 1906 ** These constants are the available integer configuration options that |
| 1907 ** can be passed as the second argument to the [sqlite3_db_config()] interface. |
| 1908 ** |
| 1909 ** New configuration options may be added in future releases of SQLite. |
| 1910 ** Existing configuration options might be discontinued. Applications |
| 1911 ** should check the return code from [sqlite3_db_config()] to make sure that |
| 1912 ** the call worked. ^The [sqlite3_db_config()] interface will return a |
| 1913 ** non-zero [error code] if a discontinued or unsupported configuration option |
| 1914 ** is invoked. |
| 1915 ** |
| 1916 ** <dl> |
| 1917 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> |
| 1918 ** <dd> ^This option takes three additional arguments that determine the |
| 1919 ** [lookaside memory allocator] configuration for the [database connection]. |
| 1920 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a |
| 1921 ** pointer to a memory buffer to use for lookaside memory. |
| 1922 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb |
| 1923 ** may be NULL in which case SQLite will allocate the |
| 1924 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the |
| 1925 ** size of each lookaside buffer slot. ^The third argument is the number of |
| 1926 ** slots. The size of the buffer in the first argument must be greater than |
| 1927 ** or equal to the product of the second and third arguments. The buffer |
| 1928 ** must be aligned to an 8-byte boundary. ^If the second argument to |
| 1929 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally |
| 1930 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory |
| 1931 ** configuration for a database connection can only be changed when that |
| 1932 ** connection is not currently using lookaside memory, or in other words |
| 1933 ** when the "current value" returned by |
| 1934 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. |
| 1935 ** Any attempt to change the lookaside memory configuration when lookaside |
| 1936 ** memory is in use leaves the configuration unchanged and returns |
| 1937 ** [SQLITE_BUSY].)^</dd> |
| 1938 ** |
| 1939 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> |
| 1940 ** <dd> ^This option is used to enable or disable the enforcement of |
| 1941 ** [foreign key constraints]. There should be two additional arguments. |
| 1942 ** The first argument is an integer which is 0 to disable FK enforcement, |
| 1943 ** positive to enable FK enforcement or negative to leave FK enforcement |
| 1944 ** unchanged. The second parameter is a pointer to an integer into which |
| 1945 ** is written 0 or 1 to indicate whether FK enforcement is off or on |
| 1946 ** following this call. The second parameter may be a NULL pointer, in |
| 1947 ** which case the FK enforcement setting is not reported back. </dd> |
| 1948 ** |
| 1949 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> |
| 1950 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. |
| 1951 ** There should be two additional arguments. |
| 1952 ** The first argument is an integer which is 0 to disable triggers, |
| 1953 ** positive to enable triggers or negative to leave the setting unchanged. |
| 1954 ** The second parameter is a pointer to an integer into which |
| 1955 ** is written 0 or 1 to indicate whether triggers are disabled or enabled |
| 1956 ** following this call. The second parameter may be a NULL pointer, in |
| 1957 ** which case the trigger setting is not reported back. </dd> |
| 1958 ** |
| 1959 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> |
| 1960 ** <dd> ^This option is used to enable or disable the two-argument |
| 1961 ** version of the [fts3_tokenizer()] function which is part of the |
| 1962 ** [FTS3] full-text search engine extension. |
| 1963 ** There should be two additional arguments. |
| 1964 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or |
| 1965 ** positive to enable fts3_tokenizer() or negative to leave the setting |
| 1966 ** unchanged. |
| 1967 ** The second parameter is a pointer to an integer into which |
| 1968 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled |
| 1969 ** following this call. The second parameter may be a NULL pointer, in |
| 1970 ** which case the new setting is not reported back. </dd> |
| 1971 ** |
| 1972 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> |
| 1973 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] |
| 1974 ** interface independently of the [load_extension()] SQL function. |
| 1975 ** The [sqlite3_enable_load_extension()] API enables or disables both the |
| 1976 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. |
| 1977 ** There should be two additional arguments. |
| 1978 ** When the first argument to this interface is 1, then only the C-API is |
| 1979 ** enabled and the SQL function remains disabled. If the first argument to |
| 1980 ** this interface is 0, then both the C-API and the SQL function are disabled. |
| 1981 ** If the first argument is -1, then no changes are made to state of either the |
| 1982 ** C-API or the SQL function. |
| 1983 ** The second parameter is a pointer to an integer into which |
| 1984 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface |
| 1985 ** is disabled or enabled following this call. The second parameter may |
| 1986 ** be a NULL pointer, in which case the new setting is not reported back. |
| 1987 ** </dd> |
| 1988 ** |
| 1989 ** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> |
| 1990 ** <dd> ^This option is used to change the name of the "main" database |
| 1991 ** schema. ^The sole argument is a pointer to a constant UTF8 string |
| 1992 ** which will become the new schema name in place of "main". ^SQLite |
| 1993 ** does not make a copy of the new main schema name string, so the application |
| 1994 ** must ensure that the argument passed into this DBCONFIG option is unchanged |
| 1995 ** until after the database connection closes. |
| 1996 ** </dd> |
| 1997 ** |
| 1998 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> |
| 1999 ** <dd> Usually, when a database in wal mode is closed or detached from a |
| 2000 ** database handle, SQLite checks if this will mean that there are now no |
| 2001 ** connections at all to the database. If so, it performs a checkpoint |
| 2002 ** operation before closing the connection. This option may be used to |
| 2003 ** override this behaviour. The first parameter passed to this operation |
| 2004 ** is an integer - non-zero to disable checkpoints-on-close, or zero (the |
| 2005 ** default) to enable them. The second parameter is a pointer to an integer |
| 2006 ** into which is written 0 or 1 to indicate whether checkpoints-on-close |
| 2007 ** have been disabled - 0 if they are not disabled, 1 if they are. |
| 2008 ** </dd> |
| 2009 ** |
| 2010 ** </dl> |
| 2011 */ |
| 2012 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ |
| 2013 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ |
| 2014 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ |
| 2015 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ |
| 2016 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ |
| 2017 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ |
| 2018 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ |
| 2019 |
| 2020 |
| 2021 /* |
| 2022 ** CAPI3REF: Enable Or Disable Extended Result Codes |
| 2023 ** METHOD: sqlite3 |
| 2024 ** |
| 2025 ** ^The sqlite3_extended_result_codes() routine enables or disables the |
| 2026 ** [extended result codes] feature of SQLite. ^The extended result |
| 2027 ** codes are disabled by default for historical compatibility. |
| 2028 */ |
| 2029 int sqlite3_extended_result_codes(sqlite3*, int onoff); |
| 2030 |
| 2031 /* |
| 2032 ** CAPI3REF: Last Insert Rowid |
| 2033 ** METHOD: sqlite3 |
| 2034 ** |
| 2035 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) |
| 2036 ** has a unique 64-bit signed |
| 2037 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available |
| 2038 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those |
| 2039 ** names are not also used by explicitly declared columns. ^If |
| 2040 ** the table has a column of type [INTEGER PRIMARY KEY] then that column |
| 2041 ** is another alias for the rowid. |
| 2042 ** |
| 2043 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the |
| 2044 ** most recent successful [INSERT] into a rowid table or [virtual table] |
| 2045 ** on database connection D. |
| 2046 ** ^Inserts into [WITHOUT ROWID] tables are not recorded. |
| 2047 ** ^If no successful [INSERT]s into rowid tables |
| 2048 ** have ever occurred on the database connection D, |
| 2049 ** then sqlite3_last_insert_rowid(D) returns zero. |
| 2050 ** |
| 2051 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] |
| 2052 ** method, then this routine will return the [rowid] of the inserted |
| 2053 ** row as long as the trigger or virtual table method is running. |
| 2054 ** But once the trigger or virtual table method ends, the value returned |
| 2055 ** by this routine reverts to what it was before the trigger or virtual |
| 2056 ** table method began.)^ |
| 2057 ** |
| 2058 ** ^An [INSERT] that fails due to a constraint violation is not a |
| 2059 ** successful [INSERT] and does not change the value returned by this |
| 2060 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, |
| 2061 ** and INSERT OR ABORT make no changes to the return value of this |
| 2062 ** routine when their insertion fails. ^(When INSERT OR REPLACE |
| 2063 ** encounters a constraint violation, it does not fail. The |
| 2064 ** INSERT continues to completion after deleting rows that caused |
| 2065 ** the constraint problem so INSERT OR REPLACE will always change |
| 2066 ** the return value of this interface.)^ |
| 2067 ** |
| 2068 ** ^For the purposes of this routine, an [INSERT] is considered to |
| 2069 ** be successful even if it is subsequently rolled back. |
| 2070 ** |
| 2071 ** This function is accessible to SQL statements via the |
| 2072 ** [last_insert_rowid() SQL function]. |
| 2073 ** |
| 2074 ** If a separate thread performs a new [INSERT] on the same |
| 2075 ** database connection while the [sqlite3_last_insert_rowid()] |
| 2076 ** function is running and thus changes the last insert [rowid], |
| 2077 ** then the value returned by [sqlite3_last_insert_rowid()] is |
| 2078 ** unpredictable and might not equal either the old or the new |
| 2079 ** last insert [rowid]. |
| 2080 */ |
| 2081 sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); |
| 2082 |
| 2083 /* |
| 2084 ** CAPI3REF: Count The Number Of Rows Modified |
| 2085 ** METHOD: sqlite3 |
| 2086 ** |
| 2087 ** ^This function returns the number of rows modified, inserted or |
| 2088 ** deleted by the most recently completed INSERT, UPDATE or DELETE |
| 2089 ** statement on the database connection specified by the only parameter. |
| 2090 ** ^Executing any other type of SQL statement does not modify the value |
| 2091 ** returned by this function. |
| 2092 ** |
| 2093 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are |
| 2094 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], |
| 2095 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. |
| 2096 ** |
| 2097 ** Changes to a view that are intercepted by |
| 2098 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value |
| 2099 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or |
| 2100 ** DELETE statement run on a view is always zero. Only changes made to real |
| 2101 ** tables are counted. |
| 2102 ** |
| 2103 ** Things are more complicated if the sqlite3_changes() function is |
| 2104 ** executed while a trigger program is running. This may happen if the |
| 2105 ** program uses the [changes() SQL function], or if some other callback |
| 2106 ** function invokes sqlite3_changes() directly. Essentially: |
| 2107 ** |
| 2108 ** <ul> |
| 2109 ** <li> ^(Before entering a trigger program the value returned by |
| 2110 ** sqlite3_changes() function is saved. After the trigger program |
| 2111 ** has finished, the original value is restored.)^ |
| 2112 ** |
| 2113 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE |
| 2114 ** statement sets the value returned by sqlite3_changes() |
| 2115 ** upon completion as normal. Of course, this value will not include |
| 2116 ** any changes performed by sub-triggers, as the sqlite3_changes() |
| 2117 ** value will be saved and restored after each sub-trigger has run.)^ |
| 2118 ** </ul> |
| 2119 ** |
| 2120 ** ^This means that if the changes() SQL function (or similar) is used |
| 2121 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it |
| 2122 ** returns the value as set when the calling statement began executing. |
| 2123 ** ^If it is used by the second or subsequent such statement within a trigger |
| 2124 ** program, the value returned reflects the number of rows modified by the |
| 2125 ** previous INSERT, UPDATE or DELETE statement within the same trigger. |
| 2126 ** |
| 2127 ** See also the [sqlite3_total_changes()] interface, the |
| 2128 ** [count_changes pragma], and the [changes() SQL function]. |
| 2129 ** |
| 2130 ** If a separate thread makes changes on the same database connection |
| 2131 ** while [sqlite3_changes()] is running then the value returned |
| 2132 ** is unpredictable and not meaningful. |
| 2133 */ |
| 2134 int sqlite3_changes(sqlite3*); |
| 2135 |
| 2136 /* |
| 2137 ** CAPI3REF: Total Number Of Rows Modified |
| 2138 ** METHOD: sqlite3 |
| 2139 ** |
| 2140 ** ^This function returns the total number of rows inserted, modified or |
| 2141 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed |
| 2142 ** since the database connection was opened, including those executed as |
| 2143 ** part of trigger programs. ^Executing any other type of SQL statement |
| 2144 ** does not affect the value returned by sqlite3_total_changes(). |
| 2145 ** |
| 2146 ** ^Changes made as part of [foreign key actions] are included in the |
| 2147 ** count, but those made as part of REPLACE constraint resolution are |
| 2148 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers |
| 2149 ** are not counted. |
| 2150 ** |
| 2151 ** See also the [sqlite3_changes()] interface, the |
| 2152 ** [count_changes pragma], and the [total_changes() SQL function]. |
| 2153 ** |
| 2154 ** If a separate thread makes changes on the same database connection |
| 2155 ** while [sqlite3_total_changes()] is running then the value |
| 2156 ** returned is unpredictable and not meaningful. |
| 2157 */ |
| 2158 int sqlite3_total_changes(sqlite3*); |
| 2159 |
| 2160 /* |
| 2161 ** CAPI3REF: Interrupt A Long-Running Query |
| 2162 ** METHOD: sqlite3 |
| 2163 ** |
| 2164 ** ^This function causes any pending database operation to abort and |
| 2165 ** return at its earliest opportunity. This routine is typically |
| 2166 ** called in response to a user action such as pressing "Cancel" |
| 2167 ** or Ctrl-C where the user wants a long query operation to halt |
| 2168 ** immediately. |
| 2169 ** |
| 2170 ** ^It is safe to call this routine from a thread different from the |
| 2171 ** thread that is currently running the database operation. But it |
| 2172 ** is not safe to call this routine with a [database connection] that |
| 2173 ** is closed or might close before sqlite3_interrupt() returns. |
| 2174 ** |
| 2175 ** ^If an SQL operation is very nearly finished at the time when |
| 2176 ** sqlite3_interrupt() is called, then it might not have an opportunity |
| 2177 ** to be interrupted and might continue to completion. |
| 2178 ** |
| 2179 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. |
| 2180 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE |
| 2181 ** that is inside an explicit transaction, then the entire transaction |
| 2182 ** will be rolled back automatically. |
| 2183 ** |
| 2184 ** ^The sqlite3_interrupt(D) call is in effect until all currently running |
| 2185 ** SQL statements on [database connection] D complete. ^Any new SQL statements |
| 2186 ** that are started after the sqlite3_interrupt() call and before the |
| 2187 ** running statements reaches zero are interrupted as if they had been |
| 2188 ** running prior to the sqlite3_interrupt() call. ^New SQL statements |
| 2189 ** that are started after the running statement count reaches zero are |
| 2190 ** not effected by the sqlite3_interrupt(). |
| 2191 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running |
| 2192 ** SQL statements is a no-op and has no effect on SQL statements |
| 2193 ** that are started after the sqlite3_interrupt() call returns. |
| 2194 ** |
| 2195 ** If the database connection closes while [sqlite3_interrupt()] |
| 2196 ** is running then bad things will likely happen. |
| 2197 */ |
| 2198 void sqlite3_interrupt(sqlite3*); |
| 2199 |
| 2200 /* |
| 2201 ** CAPI3REF: Determine If An SQL Statement Is Complete |
| 2202 ** |
| 2203 ** These routines are useful during command-line input to determine if the |
| 2204 ** currently entered text seems to form a complete SQL statement or |
| 2205 ** if additional input is needed before sending the text into |
| 2206 ** SQLite for parsing. ^These routines return 1 if the input string |
| 2207 ** appears to be a complete SQL statement. ^A statement is judged to be |
| 2208 ** complete if it ends with a semicolon token and is not a prefix of a |
| 2209 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within |
| 2210 ** string literals or quoted identifier names or comments are not |
| 2211 ** independent tokens (they are part of the token in which they are |
| 2212 ** embedded) and thus do not count as a statement terminator. ^Whitespace |
| 2213 ** and comments that follow the final semicolon are ignored. |
| 2214 ** |
| 2215 ** ^These routines return 0 if the statement is incomplete. ^If a |
| 2216 ** memory allocation fails, then SQLITE_NOMEM is returned. |
| 2217 ** |
| 2218 ** ^These routines do not parse the SQL statements thus |
| 2219 ** will not detect syntactically incorrect SQL. |
| 2220 ** |
| 2221 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior |
| 2222 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked |
| 2223 ** automatically by sqlite3_complete16(). If that initialization fails, |
| 2224 ** then the return value from sqlite3_complete16() will be non-zero |
| 2225 ** regardless of whether or not the input SQL is complete.)^ |
| 2226 ** |
| 2227 ** The input to [sqlite3_complete()] must be a zero-terminated |
| 2228 ** UTF-8 string. |
| 2229 ** |
| 2230 ** The input to [sqlite3_complete16()] must be a zero-terminated |
| 2231 ** UTF-16 string in native byte order. |
| 2232 */ |
| 2233 int sqlite3_complete(const char *sql); |
| 2234 int sqlite3_complete16(const void *sql); |
| 2235 |
| 2236 /* |
| 2237 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors |
| 2238 ** KEYWORDS: {busy-handler callback} {busy handler} |
| 2239 ** METHOD: sqlite3 |
| 2240 ** |
| 2241 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X |
| 2242 ** that might be invoked with argument P whenever |
| 2243 ** an attempt is made to access a database table associated with |
| 2244 ** [database connection] D when another thread |
| 2245 ** or process has the table locked. |
| 2246 ** The sqlite3_busy_handler() interface is used to implement |
| 2247 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. |
| 2248 ** |
| 2249 ** ^If the busy callback is NULL, then [SQLITE_BUSY] |
| 2250 ** is returned immediately upon encountering the lock. ^If the busy callback |
| 2251 ** is not NULL, then the callback might be invoked with two arguments. |
| 2252 ** |
| 2253 ** ^The first argument to the busy handler is a copy of the void* pointer which |
| 2254 ** is the third argument to sqlite3_busy_handler(). ^The second argument to |
| 2255 ** the busy handler callback is the number of times that the busy handler has |
| 2256 ** been invoked previously for the same locking event. ^If the |
| 2257 ** busy callback returns 0, then no additional attempts are made to |
| 2258 ** access the database and [SQLITE_BUSY] is returned |
| 2259 ** to the application. |
| 2260 ** ^If the callback returns non-zero, then another attempt |
| 2261 ** is made to access the database and the cycle repeats. |
| 2262 ** |
| 2263 ** The presence of a busy handler does not guarantee that it will be invoked |
| 2264 ** when there is lock contention. ^If SQLite determines that invoking the busy |
| 2265 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] |
| 2266 ** to the application instead of invoking the |
| 2267 ** busy handler. |
| 2268 ** Consider a scenario where one process is holding a read lock that |
| 2269 ** it is trying to promote to a reserved lock and |
| 2270 ** a second process is holding a reserved lock that it is trying |
| 2271 ** to promote to an exclusive lock. The first process cannot proceed |
| 2272 ** because it is blocked by the second and the second process cannot |
| 2273 ** proceed because it is blocked by the first. If both processes |
| 2274 ** invoke the busy handlers, neither will make any progress. Therefore, |
| 2275 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this |
| 2276 ** will induce the first process to release its read lock and allow |
| 2277 ** the second process to proceed. |
| 2278 ** |
| 2279 ** ^The default busy callback is NULL. |
| 2280 ** |
| 2281 ** ^(There can only be a single busy handler defined for each |
| 2282 ** [database connection]. Setting a new busy handler clears any |
| 2283 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] |
| 2284 ** or evaluating [PRAGMA busy_timeout=N] will change the |
| 2285 ** busy handler and thus clear any previously set busy handler. |
| 2286 ** |
| 2287 ** The busy callback should not take any actions which modify the |
| 2288 ** database connection that invoked the busy handler. In other words, |
| 2289 ** the busy handler is not reentrant. Any such actions |
| 2290 ** result in undefined behavior. |
| 2291 ** |
| 2292 ** A busy handler must not close the database connection |
| 2293 ** or [prepared statement] that invoked the busy handler. |
| 2294 */ |
| 2295 int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); |
| 2296 |
| 2297 /* |
| 2298 ** CAPI3REF: Set A Busy Timeout |
| 2299 ** METHOD: sqlite3 |
| 2300 ** |
| 2301 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps |
| 2302 ** for a specified amount of time when a table is locked. ^The handler |
| 2303 ** will sleep multiple times until at least "ms" milliseconds of sleeping |
| 2304 ** have accumulated. ^After at least "ms" milliseconds of sleeping, |
| 2305 ** the handler returns 0 which causes [sqlite3_step()] to return |
| 2306 ** [SQLITE_BUSY]. |
| 2307 ** |
| 2308 ** ^Calling this routine with an argument less than or equal to zero |
| 2309 ** turns off all busy handlers. |
| 2310 ** |
| 2311 ** ^(There can only be a single busy handler for a particular |
| 2312 ** [database connection] at any given moment. If another busy handler |
| 2313 ** was defined (using [sqlite3_busy_handler()]) prior to calling |
| 2314 ** this routine, that other busy handler is cleared.)^ |
| 2315 ** |
| 2316 ** See also: [PRAGMA busy_timeout] |
| 2317 */ |
| 2318 int sqlite3_busy_timeout(sqlite3*, int ms); |
| 2319 |
| 2320 /* |
| 2321 ** CAPI3REF: Convenience Routines For Running Queries |
| 2322 ** METHOD: sqlite3 |
| 2323 ** |
| 2324 ** This is a legacy interface that is preserved for backwards compatibility. |
| 2325 ** Use of this interface is not recommended. |
| 2326 ** |
| 2327 ** Definition: A <b>result table</b> is memory data structure created by the |
| 2328 ** [sqlite3_get_table()] interface. A result table records the |
| 2329 ** complete query results from one or more queries. |
| 2330 ** |
| 2331 ** The table conceptually has a number of rows and columns. But |
| 2332 ** these numbers are not part of the result table itself. These |
| 2333 ** numbers are obtained separately. Let N be the number of rows |
| 2334 ** and M be the number of columns. |
| 2335 ** |
| 2336 ** A result table is an array of pointers to zero-terminated UTF-8 strings. |
| 2337 ** There are (N+1)*M elements in the array. The first M pointers point |
| 2338 ** to zero-terminated strings that contain the names of the columns. |
| 2339 ** The remaining entries all point to query results. NULL values result |
| 2340 ** in NULL pointers. All other values are in their UTF-8 zero-terminated |
| 2341 ** string representation as returned by [sqlite3_column_text()]. |
| 2342 ** |
| 2343 ** A result table might consist of one or more memory allocations. |
| 2344 ** It is not safe to pass a result table directly to [sqlite3_free()]. |
| 2345 ** A result table should be deallocated using [sqlite3_free_table()]. |
| 2346 ** |
| 2347 ** ^(As an example of the result table format, suppose a query result |
| 2348 ** is as follows: |
| 2349 ** |
| 2350 ** <blockquote><pre> |
| 2351 ** Name | Age |
| 2352 ** ----------------------- |
| 2353 ** Alice | 43 |
| 2354 ** Bob | 28 |
| 2355 ** Cindy | 21 |
| 2356 ** </pre></blockquote> |
| 2357 ** |
| 2358 ** There are two column (M==2) and three rows (N==3). Thus the |
| 2359 ** result table has 8 entries. Suppose the result table is stored |
| 2360 ** in an array names azResult. Then azResult holds this content: |
| 2361 ** |
| 2362 ** <blockquote><pre> |
| 2363 ** azResult[0] = "Name"; |
| 2364 ** azResult[1] = "Age"; |
| 2365 ** azResult[2] = "Alice"; |
| 2366 ** azResult[3] = "43"; |
| 2367 ** azResult[4] = "Bob"; |
| 2368 ** azResult[5] = "28"; |
| 2369 ** azResult[6] = "Cindy"; |
| 2370 ** azResult[7] = "21"; |
| 2371 ** </pre></blockquote>)^ |
| 2372 ** |
| 2373 ** ^The sqlite3_get_table() function evaluates one or more |
| 2374 ** semicolon-separated SQL statements in the zero-terminated UTF-8 |
| 2375 ** string of its 2nd parameter and returns a result table to the |
| 2376 ** pointer given in its 3rd parameter. |
| 2377 ** |
| 2378 ** After the application has finished with the result from sqlite3_get_table(), |
| 2379 ** it must pass the result table pointer to sqlite3_free_table() in order to |
| 2380 ** release the memory that was malloced. Because of the way the |
| 2381 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling |
| 2382 ** function must not try to call [sqlite3_free()] directly. Only |
| 2383 ** [sqlite3_free_table()] is able to release the memory properly and safely. |
| 2384 ** |
| 2385 ** The sqlite3_get_table() interface is implemented as a wrapper around |
| 2386 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access |
| 2387 ** to any internal data structures of SQLite. It uses only the public |
| 2388 ** interface defined here. As a consequence, errors that occur in the |
| 2389 ** wrapper layer outside of the internal [sqlite3_exec()] call are not |
| 2390 ** reflected in subsequent calls to [sqlite3_errcode()] or |
| 2391 ** [sqlite3_errmsg()]. |
| 2392 */ |
| 2393 int sqlite3_get_table( |
| 2394 sqlite3 *db, /* An open database */ |
| 2395 const char *zSql, /* SQL to be evaluated */ |
| 2396 char ***pazResult, /* Results of the query */ |
| 2397 int *pnRow, /* Number of result rows written here */ |
| 2398 int *pnColumn, /* Number of result columns written here */ |
| 2399 char **pzErrmsg /* Error msg written here */ |
| 2400 ); |
| 2401 void sqlite3_free_table(char **result); |
| 2402 |
| 2403 /* |
| 2404 ** CAPI3REF: Formatted String Printing Functions |
| 2405 ** |
| 2406 ** These routines are work-alikes of the "printf()" family of functions |
| 2407 ** from the standard C library. |
| 2408 ** These routines understand most of the common K&R formatting options, |
| 2409 ** plus some additional non-standard formats, detailed below. |
| 2410 ** Note that some of the more obscure formatting options from recent |
| 2411 ** C-library standards are omitted from this implementation. |
| 2412 ** |
| 2413 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their |
| 2414 ** results into memory obtained from [sqlite3_malloc()]. |
| 2415 ** The strings returned by these two routines should be |
| 2416 ** released by [sqlite3_free()]. ^Both routines return a |
| 2417 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough |
| 2418 ** memory to hold the resulting string. |
| 2419 ** |
| 2420 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from |
| 2421 ** the standard C library. The result is written into the |
| 2422 ** buffer supplied as the second parameter whose size is given by |
| 2423 ** the first parameter. Note that the order of the |
| 2424 ** first two parameters is reversed from snprintf().)^ This is an |
| 2425 ** historical accident that cannot be fixed without breaking |
| 2426 ** backwards compatibility. ^(Note also that sqlite3_snprintf() |
| 2427 ** returns a pointer to its buffer instead of the number of |
| 2428 ** characters actually written into the buffer.)^ We admit that |
| 2429 ** the number of characters written would be a more useful return |
| 2430 ** value but we cannot change the implementation of sqlite3_snprintf() |
| 2431 ** now without breaking compatibility. |
| 2432 ** |
| 2433 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() |
| 2434 ** guarantees that the buffer is always zero-terminated. ^The first |
| 2435 ** parameter "n" is the total size of the buffer, including space for |
| 2436 ** the zero terminator. So the longest string that can be completely |
| 2437 ** written will be n-1 characters. |
| 2438 ** |
| 2439 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). |
| 2440 ** |
| 2441 ** These routines all implement some additional formatting |
| 2442 ** options that are useful for constructing SQL statements. |
| 2443 ** All of the usual printf() formatting options apply. In addition, there |
| 2444 ** is are "%q", "%Q", "%w" and "%z" options. |
| 2445 ** |
| 2446 ** ^(The %q option works like %s in that it substitutes a nul-terminated |
| 2447 ** string from the argument list. But %q also doubles every '\'' character. |
| 2448 ** %q is designed for use inside a string literal.)^ By doubling each '\'' |
| 2449 ** character it escapes that character and allows it to be inserted into |
| 2450 ** the string. |
| 2451 ** |
| 2452 ** For example, assume the string variable zText contains text as follows: |
| 2453 ** |
| 2454 ** <blockquote><pre> |
| 2455 ** char *zText = "It's a happy day!"; |
| 2456 ** </pre></blockquote> |
| 2457 ** |
| 2458 ** One can use this text in an SQL statement as follows: |
| 2459 ** |
| 2460 ** <blockquote><pre> |
| 2461 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); |
| 2462 ** sqlite3_exec(db, zSQL, 0, 0, 0); |
| 2463 ** sqlite3_free(zSQL); |
| 2464 ** </pre></blockquote> |
| 2465 ** |
| 2466 ** Because the %q format string is used, the '\'' character in zText |
| 2467 ** is escaped and the SQL generated is as follows: |
| 2468 ** |
| 2469 ** <blockquote><pre> |
| 2470 ** INSERT INTO table1 VALUES('It''s a happy day!') |
| 2471 ** </pre></blockquote> |
| 2472 ** |
| 2473 ** This is correct. Had we used %s instead of %q, the generated SQL |
| 2474 ** would have looked like this: |
| 2475 ** |
| 2476 ** <blockquote><pre> |
| 2477 ** INSERT INTO table1 VALUES('It's a happy day!'); |
| 2478 ** </pre></blockquote> |
| 2479 ** |
| 2480 ** This second example is an SQL syntax error. As a general rule you should |
| 2481 ** always use %q instead of %s when inserting text into a string literal. |
| 2482 ** |
| 2483 ** ^(The %Q option works like %q except it also adds single quotes around |
| 2484 ** the outside of the total string. Additionally, if the parameter in the |
| 2485 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without |
| 2486 ** single quotes).)^ So, for example, one could say: |
| 2487 ** |
| 2488 ** <blockquote><pre> |
| 2489 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); |
| 2490 ** sqlite3_exec(db, zSQL, 0, 0, 0); |
| 2491 ** sqlite3_free(zSQL); |
| 2492 ** </pre></blockquote> |
| 2493 ** |
| 2494 ** The code above will render a correct SQL statement in the zSQL |
| 2495 ** variable even if the zText variable is a NULL pointer. |
| 2496 ** |
| 2497 ** ^(The "%w" formatting option is like "%q" except that it expects to |
| 2498 ** be contained within double-quotes instead of single quotes, and it |
| 2499 ** escapes the double-quote character instead of the single-quote |
| 2500 ** character.)^ The "%w" formatting option is intended for safely inserting |
| 2501 ** table and column names into a constructed SQL statement. |
| 2502 ** |
| 2503 ** ^(The "%z" formatting option works like "%s" but with the |
| 2504 ** addition that after the string has been read and copied into |
| 2505 ** the result, [sqlite3_free()] is called on the input string.)^ |
| 2506 */ |
| 2507 char *sqlite3_mprintf(const char*,...); |
| 2508 char *sqlite3_vmprintf(const char*, va_list); |
| 2509 char *sqlite3_snprintf(int,char*,const char*, ...); |
| 2510 char *sqlite3_vsnprintf(int,char*,const char*, va_list); |
| 2511 |
| 2512 /* |
| 2513 ** CAPI3REF: Memory Allocation Subsystem |
| 2514 ** |
| 2515 ** The SQLite core uses these three routines for all of its own |
| 2516 ** internal memory allocation needs. "Core" in the previous sentence |
| 2517 ** does not include operating-system specific VFS implementation. The |
| 2518 ** Windows VFS uses native malloc() and free() for some operations. |
| 2519 ** |
| 2520 ** ^The sqlite3_malloc() routine returns a pointer to a block |
| 2521 ** of memory at least N bytes in length, where N is the parameter. |
| 2522 ** ^If sqlite3_malloc() is unable to obtain sufficient free |
| 2523 ** memory, it returns a NULL pointer. ^If the parameter N to |
| 2524 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns |
| 2525 ** a NULL pointer. |
| 2526 ** |
| 2527 ** ^The sqlite3_malloc64(N) routine works just like |
| 2528 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead |
| 2529 ** of a signed 32-bit integer. |
| 2530 ** |
| 2531 ** ^Calling sqlite3_free() with a pointer previously returned |
| 2532 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so |
| 2533 ** that it might be reused. ^The sqlite3_free() routine is |
| 2534 ** a no-op if is called with a NULL pointer. Passing a NULL pointer |
| 2535 ** to sqlite3_free() is harmless. After being freed, memory |
| 2536 ** should neither be read nor written. Even reading previously freed |
| 2537 ** memory might result in a segmentation fault or other severe error. |
| 2538 ** Memory corruption, a segmentation fault, or other severe error |
| 2539 ** might result if sqlite3_free() is called with a non-NULL pointer that |
| 2540 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). |
| 2541 ** |
| 2542 ** ^The sqlite3_realloc(X,N) interface attempts to resize a |
| 2543 ** prior memory allocation X to be at least N bytes. |
| 2544 ** ^If the X parameter to sqlite3_realloc(X,N) |
| 2545 ** is a NULL pointer then its behavior is identical to calling |
| 2546 ** sqlite3_malloc(N). |
| 2547 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or |
| 2548 ** negative then the behavior is exactly the same as calling |
| 2549 ** sqlite3_free(X). |
| 2550 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation |
| 2551 ** of at least N bytes in size or NULL if insufficient memory is available. |
| 2552 ** ^If M is the size of the prior allocation, then min(N,M) bytes |
| 2553 ** of the prior allocation are copied into the beginning of buffer returned |
| 2554 ** by sqlite3_realloc(X,N) and the prior allocation is freed. |
| 2555 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the |
| 2556 ** prior allocation is not freed. |
| 2557 ** |
| 2558 ** ^The sqlite3_realloc64(X,N) interfaces works the same as |
| 2559 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead |
| 2560 ** of a 32-bit signed integer. |
| 2561 ** |
| 2562 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), |
| 2563 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then |
| 2564 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. |
| 2565 ** ^The value returned by sqlite3_msize(X) might be larger than the number |
| 2566 ** of bytes requested when X was allocated. ^If X is a NULL pointer then |
| 2567 ** sqlite3_msize(X) returns zero. If X points to something that is not |
| 2568 ** the beginning of memory allocation, or if it points to a formerly |
| 2569 ** valid memory allocation that has now been freed, then the behavior |
| 2570 ** of sqlite3_msize(X) is undefined and possibly harmful. |
| 2571 ** |
| 2572 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), |
| 2573 ** sqlite3_malloc64(), and sqlite3_realloc64() |
| 2574 ** is always aligned to at least an 8 byte boundary, or to a |
| 2575 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time |
| 2576 ** option is used. |
| 2577 ** |
| 2578 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define |
| 2579 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in |
| 2580 ** implementation of these routines to be omitted. That capability |
| 2581 ** is no longer provided. Only built-in memory allocators can be used. |
| 2582 ** |
| 2583 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called |
| 2584 ** the system malloc() and free() directly when converting |
| 2585 ** filenames between the UTF-8 encoding used by SQLite |
| 2586 ** and whatever filename encoding is used by the particular Windows |
| 2587 ** installation. Memory allocation errors were detected, but |
| 2588 ** they were reported back as [SQLITE_CANTOPEN] or |
| 2589 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. |
| 2590 ** |
| 2591 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] |
| 2592 ** must be either NULL or else pointers obtained from a prior |
| 2593 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have |
| 2594 ** not yet been released. |
| 2595 ** |
| 2596 ** The application must not read or write any part of |
| 2597 ** a block of memory after it has been released using |
| 2598 ** [sqlite3_free()] or [sqlite3_realloc()]. |
| 2599 */ |
| 2600 void *sqlite3_malloc(int); |
| 2601 void *sqlite3_malloc64(sqlite3_uint64); |
| 2602 void *sqlite3_realloc(void*, int); |
| 2603 void *sqlite3_realloc64(void*, sqlite3_uint64); |
| 2604 void sqlite3_free(void*); |
| 2605 sqlite3_uint64 sqlite3_msize(void*); |
| 2606 |
| 2607 /* |
| 2608 ** CAPI3REF: Memory Allocator Statistics |
| 2609 ** |
| 2610 ** SQLite provides these two interfaces for reporting on the status |
| 2611 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] |
| 2612 ** routines, which form the built-in memory allocation subsystem. |
| 2613 ** |
| 2614 ** ^The [sqlite3_memory_used()] routine returns the number of bytes |
| 2615 ** of memory currently outstanding (malloced but not freed). |
| 2616 ** ^The [sqlite3_memory_highwater()] routine returns the maximum |
| 2617 ** value of [sqlite3_memory_used()] since the high-water mark |
| 2618 ** was last reset. ^The values returned by [sqlite3_memory_used()] and |
| 2619 ** [sqlite3_memory_highwater()] include any overhead |
| 2620 ** added by SQLite in its implementation of [sqlite3_malloc()], |
| 2621 ** but not overhead added by the any underlying system library |
| 2622 ** routines that [sqlite3_malloc()] may call. |
| 2623 ** |
| 2624 ** ^The memory high-water mark is reset to the current value of |
| 2625 ** [sqlite3_memory_used()] if and only if the parameter to |
| 2626 ** [sqlite3_memory_highwater()] is true. ^The value returned |
| 2627 ** by [sqlite3_memory_highwater(1)] is the high-water mark |
| 2628 ** prior to the reset. |
| 2629 */ |
| 2630 sqlite3_int64 sqlite3_memory_used(void); |
| 2631 sqlite3_int64 sqlite3_memory_highwater(int resetFlag); |
| 2632 |
| 2633 /* |
| 2634 ** CAPI3REF: Pseudo-Random Number Generator |
| 2635 ** |
| 2636 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to |
| 2637 ** select random [ROWID | ROWIDs] when inserting new records into a table that |
| 2638 ** already uses the largest possible [ROWID]. The PRNG is also used for |
| 2639 ** the build-in random() and randomblob() SQL functions. This interface allows |
| 2640 ** applications to access the same PRNG for other purposes. |
| 2641 ** |
| 2642 ** ^A call to this routine stores N bytes of randomness into buffer P. |
| 2643 ** ^The P parameter can be a NULL pointer. |
| 2644 ** |
| 2645 ** ^If this routine has not been previously called or if the previous |
| 2646 ** call had N less than one or a NULL pointer for P, then the PRNG is |
| 2647 ** seeded using randomness obtained from the xRandomness method of |
| 2648 ** the default [sqlite3_vfs] object. |
| 2649 ** ^If the previous call to this routine had an N of 1 or more and a |
| 2650 ** non-NULL P then the pseudo-randomness is generated |
| 2651 ** internally and without recourse to the [sqlite3_vfs] xRandomness |
| 2652 ** method. |
| 2653 */ |
| 2654 void sqlite3_randomness(int N, void *P); |
| 2655 |
| 2656 /* |
| 2657 ** CAPI3REF: Compile-Time Authorization Callbacks |
| 2658 ** METHOD: sqlite3 |
| 2659 ** |
| 2660 ** ^This routine registers an authorizer callback with a particular |
| 2661 ** [database connection], supplied in the first argument. |
| 2662 ** ^The authorizer callback is invoked as SQL statements are being compiled |
| 2663 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], |
| 2664 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various |
| 2665 ** points during the compilation process, as logic is being created |
| 2666 ** to perform various actions, the authorizer callback is invoked to |
| 2667 ** see if those actions are allowed. ^The authorizer callback should |
| 2668 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the |
| 2669 ** specific action but allow the SQL statement to continue to be |
| 2670 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be |
| 2671 ** rejected with an error. ^If the authorizer callback returns |
| 2672 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] |
| 2673 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered |
| 2674 ** the authorizer will fail with an error message. |
| 2675 ** |
| 2676 ** When the callback returns [SQLITE_OK], that means the operation |
| 2677 ** requested is ok. ^When the callback returns [SQLITE_DENY], the |
| 2678 ** [sqlite3_prepare_v2()] or equivalent call that triggered the |
| 2679 ** authorizer will fail with an error message explaining that |
| 2680 ** access is denied. |
| 2681 ** |
| 2682 ** ^The first parameter to the authorizer callback is a copy of the third |
| 2683 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter |
| 2684 ** to the callback is an integer [SQLITE_COPY | action code] that specifies |
| 2685 ** the particular action to be authorized. ^The third through sixth parameters |
| 2686 ** to the callback are zero-terminated strings that contain additional |
| 2687 ** details about the action to be authorized. |
| 2688 ** |
| 2689 ** ^If the action code is [SQLITE_READ] |
| 2690 ** and the callback returns [SQLITE_IGNORE] then the |
| 2691 ** [prepared statement] statement is constructed to substitute |
| 2692 ** a NULL value in place of the table column that would have |
| 2693 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] |
| 2694 ** return can be used to deny an untrusted user access to individual |
| 2695 ** columns of a table. |
| 2696 ** ^If the action code is [SQLITE_DELETE] and the callback returns |
| 2697 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the |
| 2698 ** [truncate optimization] is disabled and all rows are deleted individually. |
| 2699 ** |
| 2700 ** An authorizer is used when [sqlite3_prepare | preparing] |
| 2701 ** SQL statements from an untrusted source, to ensure that the SQL statements |
| 2702 ** do not try to access data they are not allowed to see, or that they do not |
| 2703 ** try to execute malicious statements that damage the database. For |
| 2704 ** example, an application may allow a user to enter arbitrary |
| 2705 ** SQL queries for evaluation by a database. But the application does |
| 2706 ** not want the user to be able to make arbitrary changes to the |
| 2707 ** database. An authorizer could then be put in place while the |
| 2708 ** user-entered SQL is being [sqlite3_prepare | prepared] that |
| 2709 ** disallows everything except [SELECT] statements. |
| 2710 ** |
| 2711 ** Applications that need to process SQL from untrusted sources |
| 2712 ** might also consider lowering resource limits using [sqlite3_limit()] |
| 2713 ** and limiting database size using the [max_page_count] [PRAGMA] |
| 2714 ** in addition to using an authorizer. |
| 2715 ** |
| 2716 ** ^(Only a single authorizer can be in place on a database connection |
| 2717 ** at a time. Each call to sqlite3_set_authorizer overrides the |
| 2718 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. |
| 2719 ** The authorizer is disabled by default. |
| 2720 ** |
| 2721 ** The authorizer callback must not do anything that will modify |
| 2722 ** the database connection that invoked the authorizer callback. |
| 2723 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
| 2724 ** database connections for the meaning of "modify" in this paragraph. |
| 2725 ** |
| 2726 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the |
| 2727 ** statement might be re-prepared during [sqlite3_step()] due to a |
| 2728 ** schema change. Hence, the application should ensure that the |
| 2729 ** correct authorizer callback remains in place during the [sqlite3_step()]. |
| 2730 ** |
| 2731 ** ^Note that the authorizer callback is invoked only during |
| 2732 ** [sqlite3_prepare()] or its variants. Authorization is not |
| 2733 ** performed during statement evaluation in [sqlite3_step()], unless |
| 2734 ** as stated in the previous paragraph, sqlite3_step() invokes |
| 2735 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. |
| 2736 */ |
| 2737 int sqlite3_set_authorizer( |
| 2738 sqlite3*, |
| 2739 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), |
| 2740 void *pUserData |
| 2741 ); |
| 2742 |
| 2743 /* |
| 2744 ** CAPI3REF: Authorizer Return Codes |
| 2745 ** |
| 2746 ** The [sqlite3_set_authorizer | authorizer callback function] must |
| 2747 ** return either [SQLITE_OK] or one of these two constants in order |
| 2748 ** to signal SQLite whether or not the action is permitted. See the |
| 2749 ** [sqlite3_set_authorizer | authorizer documentation] for additional |
| 2750 ** information. |
| 2751 ** |
| 2752 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] |
| 2753 ** returned from the [sqlite3_vtab_on_conflict()] interface. |
| 2754 */ |
| 2755 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ |
| 2756 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ |
| 2757 |
| 2758 /* |
| 2759 ** CAPI3REF: Authorizer Action Codes |
| 2760 ** |
| 2761 ** The [sqlite3_set_authorizer()] interface registers a callback function |
| 2762 ** that is invoked to authorize certain SQL statement actions. The |
| 2763 ** second parameter to the callback is an integer code that specifies |
| 2764 ** what action is being authorized. These are the integer action codes that |
| 2765 ** the authorizer callback may be passed. |
| 2766 ** |
| 2767 ** These action code values signify what kind of operation is to be |
| 2768 ** authorized. The 3rd and 4th parameters to the authorization |
| 2769 ** callback function will be parameters or NULL depending on which of these |
| 2770 ** codes is used as the second parameter. ^(The 5th parameter to the |
| 2771 ** authorizer callback is the name of the database ("main", "temp", |
| 2772 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback |
| 2773 ** is the name of the inner-most trigger or view that is responsible for |
| 2774 ** the access attempt or NULL if this access attempt is directly from |
| 2775 ** top-level SQL code. |
| 2776 */ |
| 2777 /******************************************* 3rd ************ 4th ***********/ |
| 2778 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ |
| 2779 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ |
| 2780 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ |
| 2781 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ |
| 2782 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ |
| 2783 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ |
| 2784 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ |
| 2785 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ |
| 2786 #define SQLITE_DELETE 9 /* Table Name NULL */ |
| 2787 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ |
| 2788 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ |
| 2789 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ |
| 2790 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ |
| 2791 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ |
| 2792 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ |
| 2793 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ |
| 2794 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ |
| 2795 #define SQLITE_INSERT 18 /* Table Name NULL */ |
| 2796 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ |
| 2797 #define SQLITE_READ 20 /* Table Name Column Name */ |
| 2798 #define SQLITE_SELECT 21 /* NULL NULL */ |
| 2799 #define SQLITE_TRANSACTION 22 /* Operation NULL */ |
| 2800 #define SQLITE_UPDATE 23 /* Table Name Column Name */ |
| 2801 #define SQLITE_ATTACH 24 /* Filename NULL */ |
| 2802 #define SQLITE_DETACH 25 /* Database Name NULL */ |
| 2803 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ |
| 2804 #define SQLITE_REINDEX 27 /* Index Name NULL */ |
| 2805 #define SQLITE_ANALYZE 28 /* Table Name NULL */ |
| 2806 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ |
| 2807 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ |
| 2808 #define SQLITE_FUNCTION 31 /* NULL Function Name */ |
| 2809 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ |
| 2810 #define SQLITE_COPY 0 /* No longer used */ |
| 2811 #define SQLITE_RECURSIVE 33 /* NULL NULL */ |
| 2812 |
| 2813 /* |
| 2814 ** CAPI3REF: Tracing And Profiling Functions |
| 2815 ** METHOD: sqlite3 |
| 2816 ** |
| 2817 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface |
| 2818 ** instead of the routines described here. |
| 2819 ** |
| 2820 ** These routines register callback functions that can be used for |
| 2821 ** tracing and profiling the execution of SQL statements. |
| 2822 ** |
| 2823 ** ^The callback function registered by sqlite3_trace() is invoked at |
| 2824 ** various times when an SQL statement is being run by [sqlite3_step()]. |
| 2825 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the |
| 2826 ** SQL statement text as the statement first begins executing. |
| 2827 ** ^(Additional sqlite3_trace() callbacks might occur |
| 2828 ** as each triggered subprogram is entered. The callbacks for triggers |
| 2829 ** contain a UTF-8 SQL comment that identifies the trigger.)^ |
| 2830 ** |
| 2831 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit |
| 2832 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). |
| 2833 ** |
| 2834 ** ^The callback function registered by sqlite3_profile() is invoked |
| 2835 ** as each SQL statement finishes. ^The profile callback contains |
| 2836 ** the original statement text and an estimate of wall-clock time |
| 2837 ** of how long that statement took to run. ^The profile callback |
| 2838 ** time is in units of nanoseconds, however the current implementation |
| 2839 ** is only capable of millisecond resolution so the six least significant |
| 2840 ** digits in the time are meaningless. Future versions of SQLite |
| 2841 ** might provide greater resolution on the profiler callback. The |
| 2842 ** sqlite3_profile() function is considered experimental and is |
| 2843 ** subject to change in future versions of SQLite. |
| 2844 */ |
| 2845 SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, |
| 2846 void(*xTrace)(void*,const char*), void*); |
| 2847 SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, |
| 2848 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); |
| 2849 |
| 2850 /* |
| 2851 ** CAPI3REF: SQL Trace Event Codes |
| 2852 ** KEYWORDS: SQLITE_TRACE |
| 2853 ** |
| 2854 ** These constants identify classes of events that can be monitored |
| 2855 ** using the [sqlite3_trace_v2()] tracing logic. The third argument |
| 2856 ** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of |
| 2857 ** the following constants. ^The first argument to the trace callback |
| 2858 ** is one of the following constants. |
| 2859 ** |
| 2860 ** New tracing constants may be added in future releases. |
| 2861 ** |
| 2862 ** ^A trace callback has four arguments: xCallback(T,C,P,X). |
| 2863 ** ^The T argument is one of the integer type codes above. |
| 2864 ** ^The C argument is a copy of the context pointer passed in as the |
| 2865 ** fourth argument to [sqlite3_trace_v2()]. |
| 2866 ** The P and X arguments are pointers whose meanings depend on T. |
| 2867 ** |
| 2868 ** <dl> |
| 2869 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> |
| 2870 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement |
| 2871 ** first begins running and possibly at other times during the |
| 2872 ** execution of the prepared statement, such as at the start of each |
| 2873 ** trigger subprogram. ^The P argument is a pointer to the |
| 2874 ** [prepared statement]. ^The X argument is a pointer to a string which |
| 2875 ** is the unexpanded SQL text of the prepared statement or an SQL comment |
| 2876 ** that indicates the invocation of a trigger. ^The callback can compute |
| 2877 ** the same text that would have been returned by the legacy [sqlite3_trace()] |
| 2878 ** interface by using the X argument when X begins with "--" and invoking |
| 2879 ** [sqlite3_expanded_sql(P)] otherwise. |
| 2880 ** |
| 2881 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> |
| 2882 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same |
| 2883 ** information as is provided by the [sqlite3_profile()] callback. |
| 2884 ** ^The P argument is a pointer to the [prepared statement] and the |
| 2885 ** X argument points to a 64-bit integer which is the estimated of |
| 2886 ** the number of nanosecond that the prepared statement took to run. |
| 2887 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. |
| 2888 ** |
| 2889 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> |
| 2890 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared |
| 2891 ** statement generates a single row of result. |
| 2892 ** ^The P argument is a pointer to the [prepared statement] and the |
| 2893 ** X argument is unused. |
| 2894 ** |
| 2895 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> |
| 2896 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database |
| 2897 ** connection closes. |
| 2898 ** ^The P argument is a pointer to the [database connection] object |
| 2899 ** and the X argument is unused. |
| 2900 ** </dl> |
| 2901 */ |
| 2902 #define SQLITE_TRACE_STMT 0x01 |
| 2903 #define SQLITE_TRACE_PROFILE 0x02 |
| 2904 #define SQLITE_TRACE_ROW 0x04 |
| 2905 #define SQLITE_TRACE_CLOSE 0x08 |
| 2906 |
| 2907 /* |
| 2908 ** CAPI3REF: SQL Trace Hook |
| 2909 ** METHOD: sqlite3 |
| 2910 ** |
| 2911 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback |
| 2912 ** function X against [database connection] D, using property mask M |
| 2913 ** and context pointer P. ^If the X callback is |
| 2914 ** NULL or if the M mask is zero, then tracing is disabled. The |
| 2915 ** M argument should be the bitwise OR-ed combination of |
| 2916 ** zero or more [SQLITE_TRACE] constants. |
| 2917 ** |
| 2918 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides |
| 2919 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). |
| 2920 ** |
| 2921 ** ^The X callback is invoked whenever any of the events identified by |
| 2922 ** mask M occur. ^The integer return value from the callback is currently |
| 2923 ** ignored, though this may change in future releases. Callback |
| 2924 ** implementations should return zero to ensure future compatibility. |
| 2925 ** |
| 2926 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). |
| 2927 ** ^The T argument is one of the [SQLITE_TRACE] |
| 2928 ** constants to indicate why the callback was invoked. |
| 2929 ** ^The C argument is a copy of the context pointer. |
| 2930 ** The P and X arguments are pointers whose meanings depend on T. |
| 2931 ** |
| 2932 ** The sqlite3_trace_v2() interface is intended to replace the legacy |
| 2933 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which |
| 2934 ** are deprecated. |
| 2935 */ |
| 2936 int sqlite3_trace_v2( |
| 2937 sqlite3*, |
| 2938 unsigned uMask, |
| 2939 int(*xCallback)(unsigned,void*,void*,void*), |
| 2940 void *pCtx |
| 2941 ); |
| 2942 |
| 2943 /* |
| 2944 ** CAPI3REF: Query Progress Callbacks |
| 2945 ** METHOD: sqlite3 |
| 2946 ** |
| 2947 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback |
| 2948 ** function X to be invoked periodically during long running calls to |
| 2949 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for |
| 2950 ** database connection D. An example use for this |
| 2951 ** interface is to keep a GUI updated during a large query. |
| 2952 ** |
| 2953 ** ^The parameter P is passed through as the only parameter to the |
| 2954 ** callback function X. ^The parameter N is the approximate number of |
| 2955 ** [virtual machine instructions] that are evaluated between successive |
| 2956 ** invocations of the callback X. ^If N is less than one then the progress |
| 2957 ** handler is disabled. |
| 2958 ** |
| 2959 ** ^Only a single progress handler may be defined at one time per |
| 2960 ** [database connection]; setting a new progress handler cancels the |
| 2961 ** old one. ^Setting parameter X to NULL disables the progress handler. |
| 2962 ** ^The progress handler is also disabled by setting N to a value less |
| 2963 ** than 1. |
| 2964 ** |
| 2965 ** ^If the progress callback returns non-zero, the operation is |
| 2966 ** interrupted. This feature can be used to implement a |
| 2967 ** "Cancel" button on a GUI progress dialog box. |
| 2968 ** |
| 2969 ** The progress handler callback must not do anything that will modify |
| 2970 ** the database connection that invoked the progress handler. |
| 2971 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
| 2972 ** database connections for the meaning of "modify" in this paragraph. |
| 2973 ** |
| 2974 */ |
| 2975 void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); |
| 2976 |
| 2977 /* |
| 2978 ** CAPI3REF: Opening A New Database Connection |
| 2979 ** CONSTRUCTOR: sqlite3 |
| 2980 ** |
| 2981 ** ^These routines open an SQLite database file as specified by the |
| 2982 ** filename argument. ^The filename argument is interpreted as UTF-8 for |
| 2983 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte |
| 2984 ** order for sqlite3_open16(). ^(A [database connection] handle is usually |
| 2985 ** returned in *ppDb, even if an error occurs. The only exception is that |
| 2986 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, |
| 2987 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] |
| 2988 ** object.)^ ^(If the database is opened (and/or created) successfully, then |
| 2989 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The |
| 2990 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain |
| 2991 ** an English language description of the error following a failure of any |
| 2992 ** of the sqlite3_open() routines. |
| 2993 ** |
| 2994 ** ^The default encoding will be UTF-8 for databases created using |
| 2995 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases |
| 2996 ** created using sqlite3_open16() will be UTF-16 in the native byte order. |
| 2997 ** |
| 2998 ** Whether or not an error occurs when it is opened, resources |
| 2999 ** associated with the [database connection] handle should be released by |
| 3000 ** passing it to [sqlite3_close()] when it is no longer required. |
| 3001 ** |
| 3002 ** The sqlite3_open_v2() interface works like sqlite3_open() |
| 3003 ** except that it accepts two additional parameters for additional control |
| 3004 ** over the new database connection. ^(The flags parameter to |
| 3005 ** sqlite3_open_v2() can take one of |
| 3006 ** the following three values, optionally combined with the |
| 3007 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], |
| 3008 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ |
| 3009 ** |
| 3010 ** <dl> |
| 3011 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> |
| 3012 ** <dd>The database is opened in read-only mode. If the database does not |
| 3013 ** already exist, an error is returned.</dd>)^ |
| 3014 ** |
| 3015 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> |
| 3016 ** <dd>The database is opened for reading and writing if possible, or reading |
| 3017 ** only if the file is write protected by the operating system. In either |
| 3018 ** case the database must already exist, otherwise an error is returned.</dd>)^ |
| 3019 ** |
| 3020 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> |
| 3021 ** <dd>The database is opened for reading and writing, and is created if |
| 3022 ** it does not already exist. This is the behavior that is always used for |
| 3023 ** sqlite3_open() and sqlite3_open16().</dd>)^ |
| 3024 ** </dl> |
| 3025 ** |
| 3026 ** If the 3rd parameter to sqlite3_open_v2() is not one of the |
| 3027 ** combinations shown above optionally combined with other |
| 3028 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] |
| 3029 ** then the behavior is undefined. |
| 3030 ** |
| 3031 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection |
| 3032 ** opens in the multi-thread [threading mode] as long as the single-thread |
| 3033 ** mode has not been set at compile-time or start-time. ^If the |
| 3034 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens |
| 3035 ** in the serialized [threading mode] unless single-thread was |
| 3036 ** previously selected at compile-time or start-time. |
| 3037 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be |
| 3038 ** eligible to use [shared cache mode], regardless of whether or not shared |
| 3039 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The |
| 3040 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not |
| 3041 ** participate in [shared cache mode] even if it is enabled. |
| 3042 ** |
| 3043 ** ^The fourth parameter to sqlite3_open_v2() is the name of the |
| 3044 ** [sqlite3_vfs] object that defines the operating system interface that |
| 3045 ** the new database connection should use. ^If the fourth parameter is |
| 3046 ** a NULL pointer then the default [sqlite3_vfs] object is used. |
| 3047 ** |
| 3048 ** ^If the filename is ":memory:", then a private, temporary in-memory database |
| 3049 ** is created for the connection. ^This in-memory database will vanish when |
| 3050 ** the database connection is closed. Future versions of SQLite might |
| 3051 ** make use of additional special filenames that begin with the ":" character. |
| 3052 ** It is recommended that when a database filename actually does begin with |
| 3053 ** a ":" character you should prefix the filename with a pathname such as |
| 3054 ** "./" to avoid ambiguity. |
| 3055 ** |
| 3056 ** ^If the filename is an empty string, then a private, temporary |
| 3057 ** on-disk database will be created. ^This private database will be |
| 3058 ** automatically deleted as soon as the database connection is closed. |
| 3059 ** |
| 3060 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> |
| 3061 ** |
| 3062 ** ^If [URI filename] interpretation is enabled, and the filename argument |
| 3063 ** begins with "file:", then the filename is interpreted as a URI. ^URI |
| 3064 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is |
| 3065 ** set in the fourth argument to sqlite3_open_v2(), or if it has |
| 3066 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the |
| 3067 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. |
| 3068 ** As of SQLite version 3.7.7, URI filename interpretation is turned off |
| 3069 ** by default, but future releases of SQLite might enable URI filename |
| 3070 ** interpretation by default. See "[URI filenames]" for additional |
| 3071 ** information. |
| 3072 ** |
| 3073 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an |
| 3074 ** authority, then it must be either an empty string or the string |
| 3075 ** "localhost". ^If the authority is not an empty string or "localhost", an |
| 3076 ** error is returned to the caller. ^The fragment component of a URI, if |
| 3077 ** present, is ignored. |
| 3078 ** |
| 3079 ** ^SQLite uses the path component of the URI as the name of the disk file |
| 3080 ** which contains the database. ^If the path begins with a '/' character, |
| 3081 ** then it is interpreted as an absolute path. ^If the path does not begin |
| 3082 ** with a '/' (meaning that the authority section is omitted from the URI) |
| 3083 ** then the path is interpreted as a relative path. |
| 3084 ** ^(On windows, the first component of an absolute path |
| 3085 ** is a drive specification (e.g. "C:").)^ |
| 3086 ** |
| 3087 ** [[core URI query parameters]] |
| 3088 ** The query component of a URI may contain parameters that are interpreted |
| 3089 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. |
| 3090 ** SQLite and its built-in [VFSes] interpret the |
| 3091 ** following query parameters: |
| 3092 ** |
| 3093 ** <ul> |
| 3094 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of |
| 3095 ** a VFS object that provides the operating system interface that should |
| 3096 ** be used to access the database file on disk. ^If this option is set to |
| 3097 ** an empty string the default VFS object is used. ^Specifying an unknown |
| 3098 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is |
| 3099 ** present, then the VFS specified by the option takes precedence over |
| 3100 ** the value passed as the fourth parameter to sqlite3_open_v2(). |
| 3101 ** |
| 3102 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", |
| 3103 ** "rwc", or "memory". Attempting to set it to any other value is |
| 3104 ** an error)^. |
| 3105 ** ^If "ro" is specified, then the database is opened for read-only |
| 3106 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the |
| 3107 ** third argument to sqlite3_open_v2(). ^If the mode option is set to |
| 3108 ** "rw", then the database is opened for read-write (but not create) |
| 3109 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had |
| 3110 ** been set. ^Value "rwc" is equivalent to setting both |
| 3111 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is |
| 3112 ** set to "memory" then a pure [in-memory database] that never reads |
| 3113 ** or writes from disk is used. ^It is an error to specify a value for |
| 3114 ** the mode parameter that is less restrictive than that specified by |
| 3115 ** the flags passed in the third parameter to sqlite3_open_v2(). |
| 3116 ** |
| 3117 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or |
| 3118 ** "private". ^Setting it to "shared" is equivalent to setting the |
| 3119 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to |
| 3120 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is |
| 3121 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. |
| 3122 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in |
| 3123 ** a URI filename, its value overrides any behavior requested by setting |
| 3124 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. |
| 3125 ** |
| 3126 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the |
| 3127 ** [powersafe overwrite] property does or does not apply to the |
| 3128 ** storage media on which the database file resides. |
| 3129 ** |
| 3130 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter |
| 3131 ** which if set disables file locking in rollback journal modes. This |
| 3132 ** is useful for accessing a database on a filesystem that does not |
| 3133 ** support locking. Caution: Database corruption might result if two |
| 3134 ** or more processes write to the same database and any one of those |
| 3135 ** processes uses nolock=1. |
| 3136 ** |
| 3137 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query |
| 3138 ** parameter that indicates that the database file is stored on |
| 3139 ** read-only media. ^When immutable is set, SQLite assumes that the |
| 3140 ** database file cannot be changed, even by a process with higher |
| 3141 ** privilege, and so the database is opened read-only and all locking |
| 3142 ** and change detection is disabled. Caution: Setting the immutable |
| 3143 ** property on a database file that does in fact change can result |
| 3144 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. |
| 3145 ** See also: [SQLITE_IOCAP_IMMUTABLE]. |
| 3146 ** |
| 3147 ** </ul> |
| 3148 ** |
| 3149 ** ^Specifying an unknown parameter in the query component of a URI is not an |
| 3150 ** error. Future versions of SQLite might understand additional query |
| 3151 ** parameters. See "[query parameters with special meaning to SQLite]" for |
| 3152 ** additional information. |
| 3153 ** |
| 3154 ** [[URI filename examples]] <h3>URI filename examples</h3> |
| 3155 ** |
| 3156 ** <table border="1" align=center cellpadding=5> |
| 3157 ** <tr><th> URI filenames <th> Results |
| 3158 ** <tr><td> file:data.db <td> |
| 3159 ** Open the file "data.db" in the current directory. |
| 3160 ** <tr><td> file:/home/fred/data.db<br> |
| 3161 ** file:///home/fred/data.db <br> |
| 3162 ** file://localhost/home/fred/data.db <br> <td> |
| 3163 ** Open the database file "/home/fred/data.db". |
| 3164 ** <tr><td> file://darkstar/home/fred/data.db <td> |
| 3165 ** An error. "darkstar" is not a recognized authority. |
| 3166 ** <tr><td style="white-space:nowrap"> |
| 3167 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db |
| 3168 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive |
| 3169 ** C:. Note that the %20 escaping in this example is not strictly |
| 3170 ** necessary - space characters can be used literally |
| 3171 ** in URI filenames. |
| 3172 ** <tr><td> file:data.db?mode=ro&cache=private <td> |
| 3173 ** Open file "data.db" in the current directory for read-only access. |
| 3174 ** Regardless of whether or not shared-cache mode is enabled by |
| 3175 ** default, use a private cache. |
| 3176 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> |
| 3177 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" |
| 3178 ** that uses dot-files in place of posix advisory locking. |
| 3179 ** <tr><td> file:data.db?mode=readonly <td> |
| 3180 ** An error. "readonly" is not a valid option for the "mode" parameter. |
| 3181 ** </table> |
| 3182 ** |
| 3183 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and |
| 3184 ** query components of a URI. A hexadecimal escape sequence consists of a |
| 3185 ** percent sign - "%" - followed by exactly two hexadecimal digits |
| 3186 ** specifying an octet value. ^Before the path or query components of a |
| 3187 ** URI filename are interpreted, they are encoded using UTF-8 and all |
| 3188 ** hexadecimal escape sequences replaced by a single byte containing the |
| 3189 ** corresponding octet. If this process generates an invalid UTF-8 encoding, |
| 3190 ** the results are undefined. |
| 3191 ** |
| 3192 ** <b>Note to Windows users:</b> The encoding used for the filename argument |
| 3193 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever |
| 3194 ** codepage is currently defined. Filenames containing international |
| 3195 ** characters must be converted to UTF-8 prior to passing them into |
| 3196 ** sqlite3_open() or sqlite3_open_v2(). |
| 3197 ** |
| 3198 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set |
| 3199 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various |
| 3200 ** features that require the use of temporary files may fail. |
| 3201 ** |
| 3202 ** See also: [sqlite3_temp_directory] |
| 3203 */ |
| 3204 int sqlite3_open( |
| 3205 const char *filename, /* Database filename (UTF-8) */ |
| 3206 sqlite3 **ppDb /* OUT: SQLite db handle */ |
| 3207 ); |
| 3208 int sqlite3_open16( |
| 3209 const void *filename, /* Database filename (UTF-16) */ |
| 3210 sqlite3 **ppDb /* OUT: SQLite db handle */ |
| 3211 ); |
| 3212 int sqlite3_open_v2( |
| 3213 const char *filename, /* Database filename (UTF-8) */ |
| 3214 sqlite3 **ppDb, /* OUT: SQLite db handle */ |
| 3215 int flags, /* Flags */ |
| 3216 const char *zVfs /* Name of VFS module to use */ |
| 3217 ); |
| 3218 |
| 3219 /* |
| 3220 ** CAPI3REF: Obtain Values For URI Parameters |
| 3221 ** |
| 3222 ** These are utility routines, useful to VFS implementations, that check |
| 3223 ** to see if a database file was a URI that contained a specific query |
| 3224 ** parameter, and if so obtains the value of that query parameter. |
| 3225 ** |
| 3226 ** If F is the database filename pointer passed into the xOpen() method of |
| 3227 ** a VFS implementation when the flags parameter to xOpen() has one or |
| 3228 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and |
| 3229 ** P is the name of the query parameter, then |
| 3230 ** sqlite3_uri_parameter(F,P) returns the value of the P |
| 3231 ** parameter if it exists or a NULL pointer if P does not appear as a |
| 3232 ** query parameter on F. If P is a query parameter of F |
| 3233 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns |
| 3234 ** a pointer to an empty string. |
| 3235 ** |
| 3236 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean |
| 3237 ** parameter and returns true (1) or false (0) according to the value |
| 3238 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the |
| 3239 ** value of query parameter P is one of "yes", "true", or "on" in any |
| 3240 ** case or if the value begins with a non-zero number. The |
| 3241 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of |
| 3242 ** query parameter P is one of "no", "false", or "off" in any case or |
| 3243 ** if the value begins with a numeric zero. If P is not a query |
| 3244 ** parameter on F or if the value of P is does not match any of the |
| 3245 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). |
| 3246 ** |
| 3247 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a |
| 3248 ** 64-bit signed integer and returns that integer, or D if P does not |
| 3249 ** exist. If the value of P is something other than an integer, then |
| 3250 ** zero is returned. |
| 3251 ** |
| 3252 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and |
| 3253 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and |
| 3254 ** is not a database file pathname pointer that SQLite passed into the xOpen |
| 3255 ** VFS method, then the behavior of this routine is undefined and probably |
| 3256 ** undesirable. |
| 3257 */ |
| 3258 const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); |
| 3259 int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); |
| 3260 sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); |
| 3261 |
| 3262 |
| 3263 /* |
| 3264 ** CAPI3REF: Error Codes And Messages |
| 3265 ** METHOD: sqlite3 |
| 3266 ** |
| 3267 ** ^If the most recent sqlite3_* API call associated with |
| 3268 ** [database connection] D failed, then the sqlite3_errcode(D) interface |
| 3269 ** returns the numeric [result code] or [extended result code] for that |
| 3270 ** API call. |
| 3271 ** If the most recent API call was successful, |
| 3272 ** then the return value from sqlite3_errcode() is undefined. |
| 3273 ** ^The sqlite3_extended_errcode() |
| 3274 ** interface is the same except that it always returns the |
| 3275 ** [extended result code] even when extended result codes are |
| 3276 ** disabled. |
| 3277 ** |
| 3278 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language |
| 3279 ** text that describes the error, as either UTF-8 or UTF-16 respectively. |
| 3280 ** ^(Memory to hold the error message string is managed internally. |
| 3281 ** The application does not need to worry about freeing the result. |
| 3282 ** However, the error string might be overwritten or deallocated by |
| 3283 ** subsequent calls to other SQLite interface functions.)^ |
| 3284 ** |
| 3285 ** ^The sqlite3_errstr() interface returns the English-language text |
| 3286 ** that describes the [result code], as UTF-8. |
| 3287 ** ^(Memory to hold the error message string is managed internally |
| 3288 ** and must not be freed by the application)^. |
| 3289 ** |
| 3290 ** When the serialized [threading mode] is in use, it might be the |
| 3291 ** case that a second error occurs on a separate thread in between |
| 3292 ** the time of the first error and the call to these interfaces. |
| 3293 ** When that happens, the second error will be reported since these |
| 3294 ** interfaces always report the most recent result. To avoid |
| 3295 ** this, each thread can obtain exclusive use of the [database connection] D |
| 3296 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning |
| 3297 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after |
| 3298 ** all calls to the interfaces listed here are completed. |
| 3299 ** |
| 3300 ** If an interface fails with SQLITE_MISUSE, that means the interface |
| 3301 ** was invoked incorrectly by the application. In that case, the |
| 3302 ** error code and message may or may not be set. |
| 3303 */ |
| 3304 int sqlite3_errcode(sqlite3 *db); |
| 3305 int sqlite3_extended_errcode(sqlite3 *db); |
| 3306 const char *sqlite3_errmsg(sqlite3*); |
| 3307 const void *sqlite3_errmsg16(sqlite3*); |
| 3308 const char *sqlite3_errstr(int); |
| 3309 |
| 3310 /* |
| 3311 ** CAPI3REF: Prepared Statement Object |
| 3312 ** KEYWORDS: {prepared statement} {prepared statements} |
| 3313 ** |
| 3314 ** An instance of this object represents a single SQL statement that |
| 3315 ** has been compiled into binary form and is ready to be evaluated. |
| 3316 ** |
| 3317 ** Think of each SQL statement as a separate computer program. The |
| 3318 ** original SQL text is source code. A prepared statement object |
| 3319 ** is the compiled object code. All SQL must be converted into a |
| 3320 ** prepared statement before it can be run. |
| 3321 ** |
| 3322 ** The life-cycle of a prepared statement object usually goes like this: |
| 3323 ** |
| 3324 ** <ol> |
| 3325 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. |
| 3326 ** <li> Bind values to [parameters] using the sqlite3_bind_*() |
| 3327 ** interfaces. |
| 3328 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. |
| 3329 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back |
| 3330 ** to step 2. Do this zero or more times. |
| 3331 ** <li> Destroy the object using [sqlite3_finalize()]. |
| 3332 ** </ol> |
| 3333 */ |
| 3334 typedef struct sqlite3_stmt sqlite3_stmt; |
| 3335 |
| 3336 /* |
| 3337 ** CAPI3REF: Run-time Limits |
| 3338 ** METHOD: sqlite3 |
| 3339 ** |
| 3340 ** ^(This interface allows the size of various constructs to be limited |
| 3341 ** on a connection by connection basis. The first parameter is the |
| 3342 ** [database connection] whose limit is to be set or queried. The |
| 3343 ** second parameter is one of the [limit categories] that define a |
| 3344 ** class of constructs to be size limited. The third parameter is the |
| 3345 ** new limit for that construct.)^ |
| 3346 ** |
| 3347 ** ^If the new limit is a negative number, the limit is unchanged. |
| 3348 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a |
| 3349 ** [limits | hard upper bound] |
| 3350 ** set at compile-time by a C preprocessor macro called |
| 3351 ** [limits | SQLITE_MAX_<i>NAME</i>]. |
| 3352 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ |
| 3353 ** ^Attempts to increase a limit above its hard upper bound are |
| 3354 ** silently truncated to the hard upper bound. |
| 3355 ** |
| 3356 ** ^Regardless of whether or not the limit was changed, the |
| 3357 ** [sqlite3_limit()] interface returns the prior value of the limit. |
| 3358 ** ^Hence, to find the current value of a limit without changing it, |
| 3359 ** simply invoke this interface with the third parameter set to -1. |
| 3360 ** |
| 3361 ** Run-time limits are intended for use in applications that manage |
| 3362 ** both their own internal database and also databases that are controlled |
| 3363 ** by untrusted external sources. An example application might be a |
| 3364 ** web browser that has its own databases for storing history and |
| 3365 ** separate databases controlled by JavaScript applications downloaded |
| 3366 ** off the Internet. The internal databases can be given the |
| 3367 ** large, default limits. Databases managed by external sources can |
| 3368 ** be given much smaller limits designed to prevent a denial of service |
| 3369 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] |
| 3370 ** interface to further control untrusted SQL. The size of the database |
| 3371 ** created by an untrusted script can be contained using the |
| 3372 ** [max_page_count] [PRAGMA]. |
| 3373 ** |
| 3374 ** New run-time limit categories may be added in future releases. |
| 3375 */ |
| 3376 int sqlite3_limit(sqlite3*, int id, int newVal); |
| 3377 |
| 3378 /* |
| 3379 ** CAPI3REF: Run-Time Limit Categories |
| 3380 ** KEYWORDS: {limit category} {*limit categories} |
| 3381 ** |
| 3382 ** These constants define various performance limits |
| 3383 ** that can be lowered at run-time using [sqlite3_limit()]. |
| 3384 ** The synopsis of the meanings of the various limits is shown below. |
| 3385 ** Additional information is available at [limits | Limits in SQLite]. |
| 3386 ** |
| 3387 ** <dl> |
| 3388 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> |
| 3389 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ |
| 3390 ** |
| 3391 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> |
| 3392 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ |
| 3393 ** |
| 3394 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> |
| 3395 ** <dd>The maximum number of columns in a table definition or in the |
| 3396 ** result set of a [SELECT] or the maximum number of columns in an index |
| 3397 ** or in an ORDER BY or GROUP BY clause.</dd>)^ |
| 3398 ** |
| 3399 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> |
| 3400 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ |
| 3401 ** |
| 3402 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> |
| 3403 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ |
| 3404 ** |
| 3405 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> |
| 3406 ** <dd>The maximum number of instructions in a virtual machine program |
| 3407 ** used to implement an SQL statement. This limit is not currently |
| 3408 ** enforced, though that might be added in some future release of |
| 3409 ** SQLite.</dd>)^ |
| 3410 ** |
| 3411 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> |
| 3412 ** <dd>The maximum number of arguments on a function.</dd>)^ |
| 3413 ** |
| 3414 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> |
| 3415 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> |
| 3416 ** |
| 3417 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] |
| 3418 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> |
| 3419 ** <dd>The maximum length of the pattern argument to the [LIKE] or |
| 3420 ** [GLOB] operators.</dd>)^ |
| 3421 ** |
| 3422 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] |
| 3423 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> |
| 3424 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ |
| 3425 ** |
| 3426 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> |
| 3427 ** <dd>The maximum depth of recursion for triggers.</dd>)^ |
| 3428 ** |
| 3429 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> |
| 3430 ** <dd>The maximum number of auxiliary worker threads that a single |
| 3431 ** [prepared statement] may start.</dd>)^ |
| 3432 ** </dl> |
| 3433 */ |
| 3434 #define SQLITE_LIMIT_LENGTH 0 |
| 3435 #define SQLITE_LIMIT_SQL_LENGTH 1 |
| 3436 #define SQLITE_LIMIT_COLUMN 2 |
| 3437 #define SQLITE_LIMIT_EXPR_DEPTH 3 |
| 3438 #define SQLITE_LIMIT_COMPOUND_SELECT 4 |
| 3439 #define SQLITE_LIMIT_VDBE_OP 5 |
| 3440 #define SQLITE_LIMIT_FUNCTION_ARG 6 |
| 3441 #define SQLITE_LIMIT_ATTACHED 7 |
| 3442 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 |
| 3443 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 |
| 3444 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 |
| 3445 #define SQLITE_LIMIT_WORKER_THREADS 11 |
| 3446 |
| 3447 /* |
| 3448 ** CAPI3REF: Compiling An SQL Statement |
| 3449 ** KEYWORDS: {SQL statement compiler} |
| 3450 ** METHOD: sqlite3 |
| 3451 ** CONSTRUCTOR: sqlite3_stmt |
| 3452 ** |
| 3453 ** To execute an SQL query, it must first be compiled into a byte-code |
| 3454 ** program using one of these routines. |
| 3455 ** |
| 3456 ** The first argument, "db", is a [database connection] obtained from a |
| 3457 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or |
| 3458 ** [sqlite3_open16()]. The database connection must not have been closed. |
| 3459 ** |
| 3460 ** The second argument, "zSql", is the statement to be compiled, encoded |
| 3461 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() |
| 3462 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() |
| 3463 ** use UTF-16. |
| 3464 ** |
| 3465 ** ^If the nByte argument is negative, then zSql is read up to the |
| 3466 ** first zero terminator. ^If nByte is positive, then it is the |
| 3467 ** number of bytes read from zSql. ^If nByte is zero, then no prepared |
| 3468 ** statement is generated. |
| 3469 ** If the caller knows that the supplied string is nul-terminated, then |
| 3470 ** there is a small performance advantage to passing an nByte parameter that |
| 3471 ** is the number of bytes in the input string <i>including</i> |
| 3472 ** the nul-terminator. |
| 3473 ** |
| 3474 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte |
| 3475 ** past the end of the first SQL statement in zSql. These routines only |
| 3476 ** compile the first statement in zSql, so *pzTail is left pointing to |
| 3477 ** what remains uncompiled. |
| 3478 ** |
| 3479 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be |
| 3480 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set |
| 3481 ** to NULL. ^If the input text contains no SQL (if the input is an empty |
| 3482 ** string or a comment) then *ppStmt is set to NULL. |
| 3483 ** The calling procedure is responsible for deleting the compiled |
| 3484 ** SQL statement using [sqlite3_finalize()] after it has finished with it. |
| 3485 ** ppStmt may not be NULL. |
| 3486 ** |
| 3487 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; |
| 3488 ** otherwise an [error code] is returned. |
| 3489 ** |
| 3490 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are |
| 3491 ** recommended for all new programs. The two older interfaces are retained |
| 3492 ** for backwards compatibility, but their use is discouraged. |
| 3493 ** ^In the "v2" interfaces, the prepared statement |
| 3494 ** that is returned (the [sqlite3_stmt] object) contains a copy of the |
| 3495 ** original SQL text. This causes the [sqlite3_step()] interface to |
| 3496 ** behave differently in three ways: |
| 3497 ** |
| 3498 ** <ol> |
| 3499 ** <li> |
| 3500 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it |
| 3501 ** always used to do, [sqlite3_step()] will automatically recompile the SQL |
| 3502 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] |
| 3503 ** retries will occur before sqlite3_step() gives up and returns an error. |
| 3504 ** </li> |
| 3505 ** |
| 3506 ** <li> |
| 3507 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed |
| 3508 ** [error codes] or [extended error codes]. ^The legacy behavior was that |
| 3509 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code |
| 3510 ** and the application would have to make a second call to [sqlite3_reset()] |
| 3511 ** in order to find the underlying cause of the problem. With the "v2" prepare |
| 3512 ** interfaces, the underlying reason for the error is returned immediately. |
| 3513 ** </li> |
| 3514 ** |
| 3515 ** <li> |
| 3516 ** ^If the specific value bound to [parameter | host parameter] in the |
| 3517 ** WHERE clause might influence the choice of query plan for a statement, |
| 3518 ** then the statement will be automatically recompiled, as if there had been |
| 3519 ** a schema change, on the first [sqlite3_step()] call following any change |
| 3520 ** to the [sqlite3_bind_text | bindings] of that [parameter]. |
| 3521 ** ^The specific value of WHERE-clause [parameter] might influence the |
| 3522 ** choice of query plan if the parameter is the left-hand side of a [LIKE] |
| 3523 ** or [GLOB] operator or if the parameter is compared to an indexed column |
| 3524 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. |
| 3525 ** </li> |
| 3526 ** </ol> |
| 3527 */ |
| 3528 int sqlite3_prepare( |
| 3529 sqlite3 *db, /* Database handle */ |
| 3530 const char *zSql, /* SQL statement, UTF-8 encoded */ |
| 3531 int nByte, /* Maximum length of zSql in bytes. */ |
| 3532 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
| 3533 const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
| 3534 ); |
| 3535 int sqlite3_prepare_v2( |
| 3536 sqlite3 *db, /* Database handle */ |
| 3537 const char *zSql, /* SQL statement, UTF-8 encoded */ |
| 3538 int nByte, /* Maximum length of zSql in bytes. */ |
| 3539 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
| 3540 const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
| 3541 ); |
| 3542 int sqlite3_prepare16( |
| 3543 sqlite3 *db, /* Database handle */ |
| 3544 const void *zSql, /* SQL statement, UTF-16 encoded */ |
| 3545 int nByte, /* Maximum length of zSql in bytes. */ |
| 3546 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
| 3547 const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
| 3548 ); |
| 3549 int sqlite3_prepare16_v2( |
| 3550 sqlite3 *db, /* Database handle */ |
| 3551 const void *zSql, /* SQL statement, UTF-16 encoded */ |
| 3552 int nByte, /* Maximum length of zSql in bytes. */ |
| 3553 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
| 3554 const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
| 3555 ); |
| 3556 |
| 3557 /* |
| 3558 ** CAPI3REF: Retrieving Statement SQL |
| 3559 ** METHOD: sqlite3_stmt |
| 3560 ** |
| 3561 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 |
| 3562 ** SQL text used to create [prepared statement] P if P was |
| 3563 ** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. |
| 3564 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 |
| 3565 ** string containing the SQL text of prepared statement P with |
| 3566 ** [bound parameters] expanded. |
| 3567 ** |
| 3568 ** ^(For example, if a prepared statement is created using the SQL |
| 3569 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 |
| 3570 ** and parameter :xyz is unbound, then sqlite3_sql() will return |
| 3571 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() |
| 3572 ** will return "SELECT 2345,NULL".)^ |
| 3573 ** |
| 3574 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory |
| 3575 ** is available to hold the result, or if the result would exceed the |
| 3576 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. |
| 3577 ** |
| 3578 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of |
| 3579 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time |
| 3580 ** option causes sqlite3_expanded_sql() to always return NULL. |
| 3581 ** |
| 3582 ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is |
| 3583 ** automatically freed when the prepared statement is finalized. |
| 3584 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, |
| 3585 ** is obtained from [sqlite3_malloc()] and must be free by the application |
| 3586 ** by passing it to [sqlite3_free()]. |
| 3587 */ |
| 3588 const char *sqlite3_sql(sqlite3_stmt *pStmt); |
| 3589 char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); |
| 3590 |
| 3591 /* |
| 3592 ** CAPI3REF: Determine If An SQL Statement Writes The Database |
| 3593 ** METHOD: sqlite3_stmt |
| 3594 ** |
| 3595 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if |
| 3596 ** and only if the [prepared statement] X makes no direct changes to |
| 3597 ** the content of the database file. |
| 3598 ** |
| 3599 ** Note that [application-defined SQL functions] or |
| 3600 ** [virtual tables] might change the database indirectly as a side effect. |
| 3601 ** ^(For example, if an application defines a function "eval()" that |
| 3602 ** calls [sqlite3_exec()], then the following SQL statement would |
| 3603 ** change the database file through side-effects: |
| 3604 ** |
| 3605 ** <blockquote><pre> |
| 3606 ** SELECT eval('DELETE FROM t1') FROM t2; |
| 3607 ** </pre></blockquote> |
| 3608 ** |
| 3609 ** But because the [SELECT] statement does not change the database file |
| 3610 ** directly, sqlite3_stmt_readonly() would still return true.)^ |
| 3611 ** |
| 3612 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], |
| 3613 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, |
| 3614 ** since the statements themselves do not actually modify the database but |
| 3615 ** rather they control the timing of when other statements modify the |
| 3616 ** database. ^The [ATTACH] and [DETACH] statements also cause |
| 3617 ** sqlite3_stmt_readonly() to return true since, while those statements |
| 3618 ** change the configuration of a database connection, they do not make |
| 3619 ** changes to the content of the database files on disk. |
| 3620 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since |
| 3621 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and |
| 3622 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so |
| 3623 ** sqlite3_stmt_readonly() returns false for those commands. |
| 3624 */ |
| 3625 int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); |
| 3626 |
| 3627 /* |
| 3628 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset |
| 3629 ** METHOD: sqlite3_stmt |
| 3630 ** |
| 3631 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the |
| 3632 ** [prepared statement] S has been stepped at least once using |
| 3633 ** [sqlite3_step(S)] but has neither run to completion (returned |
| 3634 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor |
| 3635 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) |
| 3636 ** interface returns false if S is a NULL pointer. If S is not a |
| 3637 ** NULL pointer and is not a pointer to a valid [prepared statement] |
| 3638 ** object, then the behavior is undefined and probably undesirable. |
| 3639 ** |
| 3640 ** This interface can be used in combination [sqlite3_next_stmt()] |
| 3641 ** to locate all prepared statements associated with a database |
| 3642 ** connection that are in need of being reset. This can be used, |
| 3643 ** for example, in diagnostic routines to search for prepared |
| 3644 ** statements that are holding a transaction open. |
| 3645 */ |
| 3646 int sqlite3_stmt_busy(sqlite3_stmt*); |
| 3647 |
| 3648 /* |
| 3649 ** CAPI3REF: Dynamically Typed Value Object |
| 3650 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} |
| 3651 ** |
| 3652 ** SQLite uses the sqlite3_value object to represent all values |
| 3653 ** that can be stored in a database table. SQLite uses dynamic typing |
| 3654 ** for the values it stores. ^Values stored in sqlite3_value objects |
| 3655 ** can be integers, floating point values, strings, BLOBs, or NULL. |
| 3656 ** |
| 3657 ** An sqlite3_value object may be either "protected" or "unprotected". |
| 3658 ** Some interfaces require a protected sqlite3_value. Other interfaces |
| 3659 ** will accept either a protected or an unprotected sqlite3_value. |
| 3660 ** Every interface that accepts sqlite3_value arguments specifies |
| 3661 ** whether or not it requires a protected sqlite3_value. The |
| 3662 ** [sqlite3_value_dup()] interface can be used to construct a new |
| 3663 ** protected sqlite3_value from an unprotected sqlite3_value. |
| 3664 ** |
| 3665 ** The terms "protected" and "unprotected" refer to whether or not |
| 3666 ** a mutex is held. An internal mutex is held for a protected |
| 3667 ** sqlite3_value object but no mutex is held for an unprotected |
| 3668 ** sqlite3_value object. If SQLite is compiled to be single-threaded |
| 3669 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) |
| 3670 ** or if SQLite is run in one of reduced mutex modes |
| 3671 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] |
| 3672 ** then there is no distinction between protected and unprotected |
| 3673 ** sqlite3_value objects and they can be used interchangeably. However, |
| 3674 ** for maximum code portability it is recommended that applications |
| 3675 ** still make the distinction between protected and unprotected |
| 3676 ** sqlite3_value objects even when not strictly required. |
| 3677 ** |
| 3678 ** ^The sqlite3_value objects that are passed as parameters into the |
| 3679 ** implementation of [application-defined SQL functions] are protected. |
| 3680 ** ^The sqlite3_value object returned by |
| 3681 ** [sqlite3_column_value()] is unprotected. |
| 3682 ** Unprotected sqlite3_value objects may only be used with |
| 3683 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. |
| 3684 ** The [sqlite3_value_blob | sqlite3_value_type()] family of |
| 3685 ** interfaces require protected sqlite3_value objects. |
| 3686 */ |
| 3687 typedef struct Mem sqlite3_value; |
| 3688 |
| 3689 /* |
| 3690 ** CAPI3REF: SQL Function Context Object |
| 3691 ** |
| 3692 ** The context in which an SQL function executes is stored in an |
| 3693 ** sqlite3_context object. ^A pointer to an sqlite3_context object |
| 3694 ** is always first parameter to [application-defined SQL functions]. |
| 3695 ** The application-defined SQL function implementation will pass this |
| 3696 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], |
| 3697 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], |
| 3698 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], |
| 3699 ** and/or [sqlite3_set_auxdata()]. |
| 3700 */ |
| 3701 typedef struct sqlite3_context sqlite3_context; |
| 3702 |
| 3703 /* |
| 3704 ** CAPI3REF: Binding Values To Prepared Statements |
| 3705 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} |
| 3706 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} |
| 3707 ** METHOD: sqlite3_stmt |
| 3708 ** |
| 3709 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, |
| 3710 ** literals may be replaced by a [parameter] that matches one of following |
| 3711 ** templates: |
| 3712 ** |
| 3713 ** <ul> |
| 3714 ** <li> ? |
| 3715 ** <li> ?NNN |
| 3716 ** <li> :VVV |
| 3717 ** <li> @VVV |
| 3718 ** <li> $VVV |
| 3719 ** </ul> |
| 3720 ** |
| 3721 ** In the templates above, NNN represents an integer literal, |
| 3722 ** and VVV represents an alphanumeric identifier.)^ ^The values of these |
| 3723 ** parameters (also called "host parameter names" or "SQL parameters") |
| 3724 ** can be set using the sqlite3_bind_*() routines defined here. |
| 3725 ** |
| 3726 ** ^The first argument to the sqlite3_bind_*() routines is always |
| 3727 ** a pointer to the [sqlite3_stmt] object returned from |
| 3728 ** [sqlite3_prepare_v2()] or its variants. |
| 3729 ** |
| 3730 ** ^The second argument is the index of the SQL parameter to be set. |
| 3731 ** ^The leftmost SQL parameter has an index of 1. ^When the same named |
| 3732 ** SQL parameter is used more than once, second and subsequent |
| 3733 ** occurrences have the same index as the first occurrence. |
| 3734 ** ^The index for named parameters can be looked up using the |
| 3735 ** [sqlite3_bind_parameter_index()] API if desired. ^The index |
| 3736 ** for "?NNN" parameters is the value of NNN. |
| 3737 ** ^The NNN value must be between 1 and the [sqlite3_limit()] |
| 3738 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). |
| 3739 ** |
| 3740 ** ^The third argument is the value to bind to the parameter. |
| 3741 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() |
| 3742 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter |
| 3743 ** is ignored and the end result is the same as sqlite3_bind_null(). |
| 3744 ** |
| 3745 ** ^(In those routines that have a fourth argument, its value is the |
| 3746 ** number of bytes in the parameter. To be clear: the value is the |
| 3747 ** number of <u>bytes</u> in the value, not the number of characters.)^ |
| 3748 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() |
| 3749 ** is negative, then the length of the string is |
| 3750 ** the number of bytes up to the first zero terminator. |
| 3751 ** If the fourth parameter to sqlite3_bind_blob() is negative, then |
| 3752 ** the behavior is undefined. |
| 3753 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() |
| 3754 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then |
| 3755 ** that parameter must be the byte offset |
| 3756 ** where the NUL terminator would occur assuming the string were NUL |
| 3757 ** terminated. If any NUL characters occur at byte offsets less than |
| 3758 ** the value of the fourth parameter then the resulting string value will |
| 3759 ** contain embedded NULs. The result of expressions involving strings |
| 3760 ** with embedded NULs is undefined. |
| 3761 ** |
| 3762 ** ^The fifth argument to the BLOB and string binding interfaces |
| 3763 ** is a destructor used to dispose of the BLOB or |
| 3764 ** string after SQLite has finished with it. ^The destructor is called |
| 3765 ** to dispose of the BLOB or string even if the call to bind API fails. |
| 3766 ** ^If the fifth argument is |
| 3767 ** the special value [SQLITE_STATIC], then SQLite assumes that the |
| 3768 ** information is in static, unmanaged space and does not need to be freed. |
| 3769 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then |
| 3770 ** SQLite makes its own private copy of the data immediately, before |
| 3771 ** the sqlite3_bind_*() routine returns. |
| 3772 ** |
| 3773 ** ^The sixth argument to sqlite3_bind_text64() must be one of |
| 3774 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] |
| 3775 ** to specify the encoding of the text in the third parameter. If |
| 3776 ** the sixth argument to sqlite3_bind_text64() is not one of the |
| 3777 ** allowed values shown above, or if the text encoding is different |
| 3778 ** from the encoding specified by the sixth parameter, then the behavior |
| 3779 ** is undefined. |
| 3780 ** |
| 3781 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that |
| 3782 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory |
| 3783 ** (just an integer to hold its size) while it is being processed. |
| 3784 ** Zeroblobs are intended to serve as placeholders for BLOBs whose |
| 3785 ** content is later written using |
| 3786 ** [sqlite3_blob_open | incremental BLOB I/O] routines. |
| 3787 ** ^A negative value for the zeroblob results in a zero-length BLOB. |
| 3788 ** |
| 3789 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer |
| 3790 ** for the [prepared statement] or with a prepared statement for which |
| 3791 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], |
| 3792 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() |
| 3793 ** routine is passed a [prepared statement] that has been finalized, the |
| 3794 ** result is undefined and probably harmful. |
| 3795 ** |
| 3796 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. |
| 3797 ** ^Unbound parameters are interpreted as NULL. |
| 3798 ** |
| 3799 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an |
| 3800 ** [error code] if anything goes wrong. |
| 3801 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB |
| 3802 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or |
| 3803 ** [SQLITE_MAX_LENGTH]. |
| 3804 ** ^[SQLITE_RANGE] is returned if the parameter |
| 3805 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. |
| 3806 ** |
| 3807 ** See also: [sqlite3_bind_parameter_count()], |
| 3808 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. |
| 3809 */ |
| 3810 int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); |
| 3811 int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, |
| 3812 void(*)(void*)); |
| 3813 int sqlite3_bind_double(sqlite3_stmt*, int, double); |
| 3814 int sqlite3_bind_int(sqlite3_stmt*, int, int); |
| 3815 int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); |
| 3816 int sqlite3_bind_null(sqlite3_stmt*, int); |
| 3817 int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); |
| 3818 int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); |
| 3819 int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, |
| 3820 void(*)(void*), unsigned char encoding); |
| 3821 int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); |
| 3822 int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); |
| 3823 int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); |
| 3824 |
| 3825 /* |
| 3826 ** CAPI3REF: Number Of SQL Parameters |
| 3827 ** METHOD: sqlite3_stmt |
| 3828 ** |
| 3829 ** ^This routine can be used to find the number of [SQL parameters] |
| 3830 ** in a [prepared statement]. SQL parameters are tokens of the |
| 3831 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as |
| 3832 ** placeholders for values that are [sqlite3_bind_blob | bound] |
| 3833 ** to the parameters at a later time. |
| 3834 ** |
| 3835 ** ^(This routine actually returns the index of the largest (rightmost) |
| 3836 ** parameter. For all forms except ?NNN, this will correspond to the |
| 3837 ** number of unique parameters. If parameters of the ?NNN form are used, |
| 3838 ** there may be gaps in the list.)^ |
| 3839 ** |
| 3840 ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
| 3841 ** [sqlite3_bind_parameter_name()], and |
| 3842 ** [sqlite3_bind_parameter_index()]. |
| 3843 */ |
| 3844 int sqlite3_bind_parameter_count(sqlite3_stmt*); |
| 3845 |
| 3846 /* |
| 3847 ** CAPI3REF: Name Of A Host Parameter |
| 3848 ** METHOD: sqlite3_stmt |
| 3849 ** |
| 3850 ** ^The sqlite3_bind_parameter_name(P,N) interface returns |
| 3851 ** the name of the N-th [SQL parameter] in the [prepared statement] P. |
| 3852 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" |
| 3853 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" |
| 3854 ** respectively. |
| 3855 ** In other words, the initial ":" or "$" or "@" or "?" |
| 3856 ** is included as part of the name.)^ |
| 3857 ** ^Parameters of the form "?" without a following integer have no name |
| 3858 ** and are referred to as "nameless" or "anonymous parameters". |
| 3859 ** |
| 3860 ** ^The first host parameter has an index of 1, not 0. |
| 3861 ** |
| 3862 ** ^If the value N is out of range or if the N-th parameter is |
| 3863 ** nameless, then NULL is returned. ^The returned string is |
| 3864 ** always in UTF-8 encoding even if the named parameter was |
| 3865 ** originally specified as UTF-16 in [sqlite3_prepare16()] or |
| 3866 ** [sqlite3_prepare16_v2()]. |
| 3867 ** |
| 3868 ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
| 3869 ** [sqlite3_bind_parameter_count()], and |
| 3870 ** [sqlite3_bind_parameter_index()]. |
| 3871 */ |
| 3872 const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); |
| 3873 |
| 3874 /* |
| 3875 ** CAPI3REF: Index Of A Parameter With A Given Name |
| 3876 ** METHOD: sqlite3_stmt |
| 3877 ** |
| 3878 ** ^Return the index of an SQL parameter given its name. ^The |
| 3879 ** index value returned is suitable for use as the second |
| 3880 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero |
| 3881 ** is returned if no matching parameter is found. ^The parameter |
| 3882 ** name must be given in UTF-8 even if the original statement |
| 3883 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. |
| 3884 ** |
| 3885 ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
| 3886 ** [sqlite3_bind_parameter_count()], and |
| 3887 ** [sqlite3_bind_parameter_name()]. |
| 3888 */ |
| 3889 int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); |
| 3890 |
| 3891 /* |
| 3892 ** CAPI3REF: Reset All Bindings On A Prepared Statement |
| 3893 ** METHOD: sqlite3_stmt |
| 3894 ** |
| 3895 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset |
| 3896 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. |
| 3897 ** ^Use this routine to reset all host parameters to NULL. |
| 3898 */ |
| 3899 int sqlite3_clear_bindings(sqlite3_stmt*); |
| 3900 |
| 3901 /* |
| 3902 ** CAPI3REF: Number Of Columns In A Result Set |
| 3903 ** METHOD: sqlite3_stmt |
| 3904 ** |
| 3905 ** ^Return the number of columns in the result set returned by the |
| 3906 ** [prepared statement]. ^If this routine returns 0, that means the |
| 3907 ** [prepared statement] returns no data (for example an [UPDATE]). |
| 3908 ** ^However, just because this routine returns a positive number does not |
| 3909 ** mean that one or more rows of data will be returned. ^A SELECT statement |
| 3910 ** will always have a positive sqlite3_column_count() but depending on the |
| 3911 ** WHERE clause constraints and the table content, it might return no rows. |
| 3912 ** |
| 3913 ** See also: [sqlite3_data_count()] |
| 3914 */ |
| 3915 int sqlite3_column_count(sqlite3_stmt *pStmt); |
| 3916 |
| 3917 /* |
| 3918 ** CAPI3REF: Column Names In A Result Set |
| 3919 ** METHOD: sqlite3_stmt |
| 3920 ** |
| 3921 ** ^These routines return the name assigned to a particular column |
| 3922 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() |
| 3923 ** interface returns a pointer to a zero-terminated UTF-8 string |
| 3924 ** and sqlite3_column_name16() returns a pointer to a zero-terminated |
| 3925 ** UTF-16 string. ^The first parameter is the [prepared statement] |
| 3926 ** that implements the [SELECT] statement. ^The second parameter is the |
| 3927 ** column number. ^The leftmost column is number 0. |
| 3928 ** |
| 3929 ** ^The returned string pointer is valid until either the [prepared statement] |
| 3930 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically |
| 3931 ** reprepared by the first call to [sqlite3_step()] for a particular run |
| 3932 ** or until the next call to |
| 3933 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. |
| 3934 ** |
| 3935 ** ^If sqlite3_malloc() fails during the processing of either routine |
| 3936 ** (for example during a conversion from UTF-8 to UTF-16) then a |
| 3937 ** NULL pointer is returned. |
| 3938 ** |
| 3939 ** ^The name of a result column is the value of the "AS" clause for |
| 3940 ** that column, if there is an AS clause. If there is no AS clause |
| 3941 ** then the name of the column is unspecified and may change from |
| 3942 ** one release of SQLite to the next. |
| 3943 */ |
| 3944 const char *sqlite3_column_name(sqlite3_stmt*, int N); |
| 3945 const void *sqlite3_column_name16(sqlite3_stmt*, int N); |
| 3946 |
| 3947 /* |
| 3948 ** CAPI3REF: Source Of Data In A Query Result |
| 3949 ** METHOD: sqlite3_stmt |
| 3950 ** |
| 3951 ** ^These routines provide a means to determine the database, table, and |
| 3952 ** table column that is the origin of a particular result column in |
| 3953 ** [SELECT] statement. |
| 3954 ** ^The name of the database or table or column can be returned as |
| 3955 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return |
| 3956 ** the database name, the _table_ routines return the table name, and |
| 3957 ** the origin_ routines return the column name. |
| 3958 ** ^The returned string is valid until the [prepared statement] is destroyed |
| 3959 ** using [sqlite3_finalize()] or until the statement is automatically |
| 3960 ** reprepared by the first call to [sqlite3_step()] for a particular run |
| 3961 ** or until the same information is requested |
| 3962 ** again in a different encoding. |
| 3963 ** |
| 3964 ** ^The names returned are the original un-aliased names of the |
| 3965 ** database, table, and column. |
| 3966 ** |
| 3967 ** ^The first argument to these interfaces is a [prepared statement]. |
| 3968 ** ^These functions return information about the Nth result column returned by |
| 3969 ** the statement, where N is the second function argument. |
| 3970 ** ^The left-most column is column 0 for these routines. |
| 3971 ** |
| 3972 ** ^If the Nth column returned by the statement is an expression or |
| 3973 ** subquery and is not a column value, then all of these functions return |
| 3974 ** NULL. ^These routine might also return NULL if a memory allocation error |
| 3975 ** occurs. ^Otherwise, they return the name of the attached database, table, |
| 3976 ** or column that query result column was extracted from. |
| 3977 ** |
| 3978 ** ^As with all other SQLite APIs, those whose names end with "16" return |
| 3979 ** UTF-16 encoded strings and the other functions return UTF-8. |
| 3980 ** |
| 3981 ** ^These APIs are only available if the library was compiled with the |
| 3982 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. |
| 3983 ** |
| 3984 ** If two or more threads call one or more of these routines against the same |
| 3985 ** prepared statement and column at the same time then the results are |
| 3986 ** undefined. |
| 3987 ** |
| 3988 ** If two or more threads call one or more |
| 3989 ** [sqlite3_column_database_name | column metadata interfaces] |
| 3990 ** for the same [prepared statement] and result column |
| 3991 ** at the same time then the results are undefined. |
| 3992 */ |
| 3993 const char *sqlite3_column_database_name(sqlite3_stmt*,int); |
| 3994 const void *sqlite3_column_database_name16(sqlite3_stmt*,int); |
| 3995 const char *sqlite3_column_table_name(sqlite3_stmt*,int); |
| 3996 const void *sqlite3_column_table_name16(sqlite3_stmt*,int); |
| 3997 const char *sqlite3_column_origin_name(sqlite3_stmt*,int); |
| 3998 const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); |
| 3999 |
| 4000 /* |
| 4001 ** CAPI3REF: Declared Datatype Of A Query Result |
| 4002 ** METHOD: sqlite3_stmt |
| 4003 ** |
| 4004 ** ^(The first parameter is a [prepared statement]. |
| 4005 ** If this statement is a [SELECT] statement and the Nth column of the |
| 4006 ** returned result set of that [SELECT] is a table column (not an |
| 4007 ** expression or subquery) then the declared type of the table |
| 4008 ** column is returned.)^ ^If the Nth column of the result set is an |
| 4009 ** expression or subquery, then a NULL pointer is returned. |
| 4010 ** ^The returned string is always UTF-8 encoded. |
| 4011 ** |
| 4012 ** ^(For example, given the database schema: |
| 4013 ** |
| 4014 ** CREATE TABLE t1(c1 VARIANT); |
| 4015 ** |
| 4016 ** and the following statement to be compiled: |
| 4017 ** |
| 4018 ** SELECT c1 + 1, c1 FROM t1; |
| 4019 ** |
| 4020 ** this routine would return the string "VARIANT" for the second result |
| 4021 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ |
| 4022 ** |
| 4023 ** ^SQLite uses dynamic run-time typing. ^So just because a column |
| 4024 ** is declared to contain a particular type does not mean that the |
| 4025 ** data stored in that column is of the declared type. SQLite is |
| 4026 ** strongly typed, but the typing is dynamic not static. ^Type |
| 4027 ** is associated with individual values, not with the containers |
| 4028 ** used to hold those values. |
| 4029 */ |
| 4030 const char *sqlite3_column_decltype(sqlite3_stmt*,int); |
| 4031 const void *sqlite3_column_decltype16(sqlite3_stmt*,int); |
| 4032 |
| 4033 /* |
| 4034 ** CAPI3REF: Evaluate An SQL Statement |
| 4035 ** METHOD: sqlite3_stmt |
| 4036 ** |
| 4037 ** After a [prepared statement] has been prepared using either |
| 4038 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy |
| 4039 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function |
| 4040 ** must be called one or more times to evaluate the statement. |
| 4041 ** |
| 4042 ** The details of the behavior of the sqlite3_step() interface depend |
| 4043 ** on whether the statement was prepared using the newer "v2" interface |
| 4044 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy |
| 4045 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the |
| 4046 ** new "v2" interface is recommended for new applications but the legacy |
| 4047 ** interface will continue to be supported. |
| 4048 ** |
| 4049 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], |
| 4050 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. |
| 4051 ** ^With the "v2" interface, any of the other [result codes] or |
| 4052 ** [extended result codes] might be returned as well. |
| 4053 ** |
| 4054 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the |
| 4055 ** database locks it needs to do its job. ^If the statement is a [COMMIT] |
| 4056 ** or occurs outside of an explicit transaction, then you can retry the |
| 4057 ** statement. If the statement is not a [COMMIT] and occurs within an |
| 4058 ** explicit transaction then you should rollback the transaction before |
| 4059 ** continuing. |
| 4060 ** |
| 4061 ** ^[SQLITE_DONE] means that the statement has finished executing |
| 4062 ** successfully. sqlite3_step() should not be called again on this virtual |
| 4063 ** machine without first calling [sqlite3_reset()] to reset the virtual |
| 4064 ** machine back to its initial state. |
| 4065 ** |
| 4066 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] |
| 4067 ** is returned each time a new row of data is ready for processing by the |
| 4068 ** caller. The values may be accessed using the [column access functions]. |
| 4069 ** sqlite3_step() is called again to retrieve the next row of data. |
| 4070 ** |
| 4071 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint |
| 4072 ** violation) has occurred. sqlite3_step() should not be called again on |
| 4073 ** the VM. More information may be found by calling [sqlite3_errmsg()]. |
| 4074 ** ^With the legacy interface, a more specific error code (for example, |
| 4075 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) |
| 4076 ** can be obtained by calling [sqlite3_reset()] on the |
| 4077 ** [prepared statement]. ^In the "v2" interface, |
| 4078 ** the more specific error code is returned directly by sqlite3_step(). |
| 4079 ** |
| 4080 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. |
| 4081 ** Perhaps it was called on a [prepared statement] that has |
| 4082 ** already been [sqlite3_finalize | finalized] or on one that had |
| 4083 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could |
| 4084 ** be the case that the same database connection is being used by two or |
| 4085 ** more threads at the same moment in time. |
| 4086 ** |
| 4087 ** For all versions of SQLite up to and including 3.6.23.1, a call to |
| 4088 ** [sqlite3_reset()] was required after sqlite3_step() returned anything |
| 4089 ** other than [SQLITE_ROW] before any subsequent invocation of |
| 4090 ** sqlite3_step(). Failure to reset the prepared statement using |
| 4091 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from |
| 4092 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], |
| 4093 ** sqlite3_step() began |
| 4094 ** calling [sqlite3_reset()] automatically in this circumstance rather |
| 4095 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility |
| 4096 ** break because any application that ever receives an SQLITE_MISUSE error |
| 4097 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option |
| 4098 ** can be used to restore the legacy behavior. |
| 4099 ** |
| 4100 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() |
| 4101 ** API always returns a generic error code, [SQLITE_ERROR], following any |
| 4102 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call |
| 4103 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the |
| 4104 ** specific [error codes] that better describes the error. |
| 4105 ** We admit that this is a goofy design. The problem has been fixed |
| 4106 ** with the "v2" interface. If you prepare all of your SQL statements |
| 4107 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead |
| 4108 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, |
| 4109 ** then the more specific [error codes] are returned directly |
| 4110 ** by sqlite3_step(). The use of the "v2" interface is recommended. |
| 4111 */ |
| 4112 int sqlite3_step(sqlite3_stmt*); |
| 4113 |
| 4114 /* |
| 4115 ** CAPI3REF: Number of columns in a result set |
| 4116 ** METHOD: sqlite3_stmt |
| 4117 ** |
| 4118 ** ^The sqlite3_data_count(P) interface returns the number of columns in the |
| 4119 ** current row of the result set of [prepared statement] P. |
| 4120 ** ^If prepared statement P does not have results ready to return |
| 4121 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of |
| 4122 ** interfaces) then sqlite3_data_count(P) returns 0. |
| 4123 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. |
| 4124 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to |
| 4125 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) |
| 4126 ** will return non-zero if previous call to [sqlite3_step](P) returned |
| 4127 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] |
| 4128 ** where it always returns zero since each step of that multi-step |
| 4129 ** pragma returns 0 columns of data. |
| 4130 ** |
| 4131 ** See also: [sqlite3_column_count()] |
| 4132 */ |
| 4133 int sqlite3_data_count(sqlite3_stmt *pStmt); |
| 4134 |
| 4135 /* |
| 4136 ** CAPI3REF: Fundamental Datatypes |
| 4137 ** KEYWORDS: SQLITE_TEXT |
| 4138 ** |
| 4139 ** ^(Every value in SQLite has one of five fundamental datatypes: |
| 4140 ** |
| 4141 ** <ul> |
| 4142 ** <li> 64-bit signed integer |
| 4143 ** <li> 64-bit IEEE floating point number |
| 4144 ** <li> string |
| 4145 ** <li> BLOB |
| 4146 ** <li> NULL |
| 4147 ** </ul>)^ |
| 4148 ** |
| 4149 ** These constants are codes for each of those types. |
| 4150 ** |
| 4151 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 |
| 4152 ** for a completely different meaning. Software that links against both |
| 4153 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not |
| 4154 ** SQLITE_TEXT. |
| 4155 */ |
| 4156 #define SQLITE_INTEGER 1 |
| 4157 #define SQLITE_FLOAT 2 |
| 4158 #define SQLITE_BLOB 4 |
| 4159 #define SQLITE_NULL 5 |
| 4160 #ifdef SQLITE_TEXT |
| 4161 # undef SQLITE_TEXT |
| 4162 #else |
| 4163 # define SQLITE_TEXT 3 |
| 4164 #endif |
| 4165 #define SQLITE3_TEXT 3 |
| 4166 |
| 4167 /* |
| 4168 ** CAPI3REF: Result Values From A Query |
| 4169 ** KEYWORDS: {column access functions} |
| 4170 ** METHOD: sqlite3_stmt |
| 4171 ** |
| 4172 ** ^These routines return information about a single column of the current |
| 4173 ** result row of a query. ^In every case the first argument is a pointer |
| 4174 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] |
| 4175 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) |
| 4176 ** and the second argument is the index of the column for which information |
| 4177 ** should be returned. ^The leftmost column of the result set has the index 0. |
| 4178 ** ^The number of columns in the result can be determined using |
| 4179 ** [sqlite3_column_count()]. |
| 4180 ** |
| 4181 ** If the SQL statement does not currently point to a valid row, or if the |
| 4182 ** column index is out of range, the result is undefined. |
| 4183 ** These routines may only be called when the most recent call to |
| 4184 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither |
| 4185 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. |
| 4186 ** If any of these routines are called after [sqlite3_reset()] or |
| 4187 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned |
| 4188 ** something other than [SQLITE_ROW], the results are undefined. |
| 4189 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] |
| 4190 ** are called from a different thread while any of these routines |
| 4191 ** are pending, then the results are undefined. |
| 4192 ** |
| 4193 ** ^The sqlite3_column_type() routine returns the |
| 4194 ** [SQLITE_INTEGER | datatype code] for the initial data type |
| 4195 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], |
| 4196 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value |
| 4197 ** returned by sqlite3_column_type() is only meaningful if no type |
| 4198 ** conversions have occurred as described below. After a type conversion, |
| 4199 ** the value returned by sqlite3_column_type() is undefined. Future |
| 4200 ** versions of SQLite may change the behavior of sqlite3_column_type() |
| 4201 ** following a type conversion. |
| 4202 ** |
| 4203 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() |
| 4204 ** routine returns the number of bytes in that BLOB or string. |
| 4205 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts |
| 4206 ** the string to UTF-8 and then returns the number of bytes. |
| 4207 ** ^If the result is a numeric value then sqlite3_column_bytes() uses |
| 4208 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns |
| 4209 ** the number of bytes in that string. |
| 4210 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. |
| 4211 ** |
| 4212 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() |
| 4213 ** routine returns the number of bytes in that BLOB or string. |
| 4214 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts |
| 4215 ** the string to UTF-16 and then returns the number of bytes. |
| 4216 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses |
| 4217 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns |
| 4218 ** the number of bytes in that string. |
| 4219 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. |
| 4220 ** |
| 4221 ** ^The values returned by [sqlite3_column_bytes()] and |
| 4222 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end |
| 4223 ** of the string. ^For clarity: the values returned by |
| 4224 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of |
| 4225 ** bytes in the string, not the number of characters. |
| 4226 ** |
| 4227 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), |
| 4228 ** even empty strings, are always zero-terminated. ^The return |
| 4229 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. |
| 4230 ** |
| 4231 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an |
| 4232 ** [unprotected sqlite3_value] object. In a multithreaded environment, |
| 4233 ** an unprotected sqlite3_value object may only be used safely with |
| 4234 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. |
| 4235 ** If the [unprotected sqlite3_value] object returned by |
| 4236 ** [sqlite3_column_value()] is used in any other way, including calls |
| 4237 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], |
| 4238 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. |
| 4239 ** |
| 4240 ** These routines attempt to convert the value where appropriate. ^For |
| 4241 ** example, if the internal representation is FLOAT and a text result |
| 4242 ** is requested, [sqlite3_snprintf()] is used internally to perform the |
| 4243 ** conversion automatically. ^(The following table details the conversions |
| 4244 ** that are applied: |
| 4245 ** |
| 4246 ** <blockquote> |
| 4247 ** <table border="1"> |
| 4248 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion |
| 4249 ** |
| 4250 ** <tr><td> NULL <td> INTEGER <td> Result is 0 |
| 4251 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 |
| 4252 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer |
| 4253 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer |
| 4254 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float |
| 4255 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer |
| 4256 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT |
| 4257 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER |
| 4258 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float |
| 4259 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB |
| 4260 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER |
| 4261 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL |
| 4262 ** <tr><td> TEXT <td> BLOB <td> No change |
| 4263 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER |
| 4264 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL |
| 4265 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed |
| 4266 ** </table> |
| 4267 ** </blockquote>)^ |
| 4268 ** |
| 4269 ** Note that when type conversions occur, pointers returned by prior |
| 4270 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or |
| 4271 ** sqlite3_column_text16() may be invalidated. |
| 4272 ** Type conversions and pointer invalidations might occur |
| 4273 ** in the following cases: |
| 4274 ** |
| 4275 ** <ul> |
| 4276 ** <li> The initial content is a BLOB and sqlite3_column_text() or |
| 4277 ** sqlite3_column_text16() is called. A zero-terminator might |
| 4278 ** need to be added to the string.</li> |
| 4279 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or |
| 4280 ** sqlite3_column_text16() is called. The content must be converted |
| 4281 ** to UTF-16.</li> |
| 4282 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or |
| 4283 ** sqlite3_column_text() is called. The content must be converted |
| 4284 ** to UTF-8.</li> |
| 4285 ** </ul> |
| 4286 ** |
| 4287 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do |
| 4288 ** not invalidate a prior pointer, though of course the content of the buffer |
| 4289 ** that the prior pointer references will have been modified. Other kinds |
| 4290 ** of conversion are done in place when it is possible, but sometimes they |
| 4291 ** are not possible and in those cases prior pointers are invalidated. |
| 4292 ** |
| 4293 ** The safest policy is to invoke these routines |
| 4294 ** in one of the following ways: |
| 4295 ** |
| 4296 ** <ul> |
| 4297 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> |
| 4298 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> |
| 4299 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> |
| 4300 ** </ul> |
| 4301 ** |
| 4302 ** In other words, you should call sqlite3_column_text(), |
| 4303 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result |
| 4304 ** into the desired format, then invoke sqlite3_column_bytes() or |
| 4305 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls |
| 4306 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to |
| 4307 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() |
| 4308 ** with calls to sqlite3_column_bytes(). |
| 4309 ** |
| 4310 ** ^The pointers returned are valid until a type conversion occurs as |
| 4311 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or |
| 4312 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings |
| 4313 ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned |
| 4314 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into |
| 4315 ** [sqlite3_free()]. |
| 4316 ** |
| 4317 ** ^(If a memory allocation error occurs during the evaluation of any |
| 4318 ** of these routines, a default value is returned. The default value |
| 4319 ** is either the integer 0, the floating point number 0.0, or a NULL |
| 4320 ** pointer. Subsequent calls to [sqlite3_errcode()] will return |
| 4321 ** [SQLITE_NOMEM].)^ |
| 4322 */ |
| 4323 const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); |
| 4324 int sqlite3_column_bytes(sqlite3_stmt*, int iCol); |
| 4325 int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); |
| 4326 double sqlite3_column_double(sqlite3_stmt*, int iCol); |
| 4327 int sqlite3_column_int(sqlite3_stmt*, int iCol); |
| 4328 sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); |
| 4329 const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); |
| 4330 const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); |
| 4331 int sqlite3_column_type(sqlite3_stmt*, int iCol); |
| 4332 sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); |
| 4333 |
| 4334 /* |
| 4335 ** CAPI3REF: Destroy A Prepared Statement Object |
| 4336 ** DESTRUCTOR: sqlite3_stmt |
| 4337 ** |
| 4338 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. |
| 4339 ** ^If the most recent evaluation of the statement encountered no errors |
| 4340 ** or if the statement is never been evaluated, then sqlite3_finalize() returns |
| 4341 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then |
| 4342 ** sqlite3_finalize(S) returns the appropriate [error code] or |
| 4343 ** [extended error code]. |
| 4344 ** |
| 4345 ** ^The sqlite3_finalize(S) routine can be called at any point during |
| 4346 ** the life cycle of [prepared statement] S: |
| 4347 ** before statement S is ever evaluated, after |
| 4348 ** one or more calls to [sqlite3_reset()], or after any call |
| 4349 ** to [sqlite3_step()] regardless of whether or not the statement has |
| 4350 ** completed execution. |
| 4351 ** |
| 4352 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. |
| 4353 ** |
| 4354 ** The application must finalize every [prepared statement] in order to avoid |
| 4355 ** resource leaks. It is a grievous error for the application to try to use |
| 4356 ** a prepared statement after it has been finalized. Any use of a prepared |
| 4357 ** statement after it has been finalized can result in undefined and |
| 4358 ** undesirable behavior such as segfaults and heap corruption. |
| 4359 */ |
| 4360 int sqlite3_finalize(sqlite3_stmt *pStmt); |
| 4361 |
| 4362 /* |
| 4363 ** CAPI3REF: Reset A Prepared Statement Object |
| 4364 ** METHOD: sqlite3_stmt |
| 4365 ** |
| 4366 ** The sqlite3_reset() function is called to reset a [prepared statement] |
| 4367 ** object back to its initial state, ready to be re-executed. |
| 4368 ** ^Any SQL statement variables that had values bound to them using |
| 4369 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. |
| 4370 ** Use [sqlite3_clear_bindings()] to reset the bindings. |
| 4371 ** |
| 4372 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S |
| 4373 ** back to the beginning of its program. |
| 4374 ** |
| 4375 ** ^If the most recent call to [sqlite3_step(S)] for the |
| 4376 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], |
| 4377 ** or if [sqlite3_step(S)] has never before been called on S, |
| 4378 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. |
| 4379 ** |
| 4380 ** ^If the most recent call to [sqlite3_step(S)] for the |
| 4381 ** [prepared statement] S indicated an error, then |
| 4382 ** [sqlite3_reset(S)] returns an appropriate [error code]. |
| 4383 ** |
| 4384 ** ^The [sqlite3_reset(S)] interface does not change the values |
| 4385 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. |
| 4386 */ |
| 4387 int sqlite3_reset(sqlite3_stmt *pStmt); |
| 4388 |
| 4389 /* |
| 4390 ** CAPI3REF: Create Or Redefine SQL Functions |
| 4391 ** KEYWORDS: {function creation routines} |
| 4392 ** KEYWORDS: {application-defined SQL function} |
| 4393 ** KEYWORDS: {application-defined SQL functions} |
| 4394 ** METHOD: sqlite3 |
| 4395 ** |
| 4396 ** ^These functions (collectively known as "function creation routines") |
| 4397 ** are used to add SQL functions or aggregates or to redefine the behavior |
| 4398 ** of existing SQL functions or aggregates. The only differences between |
| 4399 ** these routines are the text encoding expected for |
| 4400 ** the second parameter (the name of the function being created) |
| 4401 ** and the presence or absence of a destructor callback for |
| 4402 ** the application data pointer. |
| 4403 ** |
| 4404 ** ^The first parameter is the [database connection] to which the SQL |
| 4405 ** function is to be added. ^If an application uses more than one database |
| 4406 ** connection then application-defined SQL functions must be added |
| 4407 ** to each database connection separately. |
| 4408 ** |
| 4409 ** ^The second parameter is the name of the SQL function to be created or |
| 4410 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 |
| 4411 ** representation, exclusive of the zero-terminator. ^Note that the name |
| 4412 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. |
| 4413 ** ^Any attempt to create a function with a longer name |
| 4414 ** will result in [SQLITE_MISUSE] being returned. |
| 4415 ** |
| 4416 ** ^The third parameter (nArg) |
| 4417 ** is the number of arguments that the SQL function or |
| 4418 ** aggregate takes. ^If this parameter is -1, then the SQL function or |
| 4419 ** aggregate may take any number of arguments between 0 and the limit |
| 4420 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third |
| 4421 ** parameter is less than -1 or greater than 127 then the behavior is |
| 4422 ** undefined. |
| 4423 ** |
| 4424 ** ^The fourth parameter, eTextRep, specifies what |
| 4425 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for |
| 4426 ** its parameters. The application should set this parameter to |
| 4427 ** [SQLITE_UTF16LE] if the function implementation invokes |
| 4428 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the |
| 4429 ** implementation invokes [sqlite3_value_text16be()] on an input, or |
| 4430 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] |
| 4431 ** otherwise. ^The same SQL function may be registered multiple times using |
| 4432 ** different preferred text encodings, with different implementations for |
| 4433 ** each encoding. |
| 4434 ** ^When multiple implementations of the same function are available, SQLite |
| 4435 ** will pick the one that involves the least amount of data conversion. |
| 4436 ** |
| 4437 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] |
| 4438 ** to signal that the function will always return the same result given |
| 4439 ** the same inputs within a single SQL statement. Most SQL functions are |
| 4440 ** deterministic. The built-in [random()] SQL function is an example of a |
| 4441 ** function that is not deterministic. The SQLite query planner is able to |
| 4442 ** perform additional optimizations on deterministic functions, so use |
| 4443 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. |
| 4444 ** |
| 4445 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the |
| 4446 ** function can gain access to this pointer using [sqlite3_user_data()].)^ |
| 4447 ** |
| 4448 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are |
| 4449 ** pointers to C-language functions that implement the SQL function or |
| 4450 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc |
| 4451 ** callback only; NULL pointers must be passed as the xStep and xFinal |
| 4452 ** parameters. ^An aggregate SQL function requires an implementation of xStep |
| 4453 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing |
| 4454 ** SQL function or aggregate, pass NULL pointers for all three function |
| 4455 ** callbacks. |
| 4456 ** |
| 4457 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, |
| 4458 ** then it is destructor for the application data pointer. |
| 4459 ** The destructor is invoked when the function is deleted, either by being |
| 4460 ** overloaded or when the database connection closes.)^ |
| 4461 ** ^The destructor is also invoked if the call to |
| 4462 ** sqlite3_create_function_v2() fails. |
| 4463 ** ^When the destructor callback of the tenth parameter is invoked, it |
| 4464 ** is passed a single argument which is a copy of the application data |
| 4465 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). |
| 4466 ** |
| 4467 ** ^It is permitted to register multiple implementations of the same |
| 4468 ** functions with the same name but with either differing numbers of |
| 4469 ** arguments or differing preferred text encodings. ^SQLite will use |
| 4470 ** the implementation that most closely matches the way in which the |
| 4471 ** SQL function is used. ^A function implementation with a non-negative |
| 4472 ** nArg parameter is a better match than a function implementation with |
| 4473 ** a negative nArg. ^A function where the preferred text encoding |
| 4474 ** matches the database encoding is a better |
| 4475 ** match than a function where the encoding is different. |
| 4476 ** ^A function where the encoding difference is between UTF16le and UTF16be |
| 4477 ** is a closer match than a function where the encoding difference is |
| 4478 ** between UTF8 and UTF16. |
| 4479 ** |
| 4480 ** ^Built-in functions may be overloaded by new application-defined functions. |
| 4481 ** |
| 4482 ** ^An application-defined function is permitted to call other |
| 4483 ** SQLite interfaces. However, such calls must not |
| 4484 ** close the database connection nor finalize or reset the prepared |
| 4485 ** statement in which the function is running. |
| 4486 */ |
| 4487 int sqlite3_create_function( |
| 4488 sqlite3 *db, |
| 4489 const char *zFunctionName, |
| 4490 int nArg, |
| 4491 int eTextRep, |
| 4492 void *pApp, |
| 4493 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
| 4494 void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
| 4495 void (*xFinal)(sqlite3_context*) |
| 4496 ); |
| 4497 int sqlite3_create_function16( |
| 4498 sqlite3 *db, |
| 4499 const void *zFunctionName, |
| 4500 int nArg, |
| 4501 int eTextRep, |
| 4502 void *pApp, |
| 4503 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
| 4504 void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
| 4505 void (*xFinal)(sqlite3_context*) |
| 4506 ); |
| 4507 int sqlite3_create_function_v2( |
| 4508 sqlite3 *db, |
| 4509 const char *zFunctionName, |
| 4510 int nArg, |
| 4511 int eTextRep, |
| 4512 void *pApp, |
| 4513 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
| 4514 void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
| 4515 void (*xFinal)(sqlite3_context*), |
| 4516 void(*xDestroy)(void*) |
| 4517 ); |
| 4518 |
| 4519 /* |
| 4520 ** CAPI3REF: Text Encodings |
| 4521 ** |
| 4522 ** These constant define integer codes that represent the various |
| 4523 ** text encodings supported by SQLite. |
| 4524 */ |
| 4525 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ |
| 4526 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ |
| 4527 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ |
| 4528 #define SQLITE_UTF16 4 /* Use native byte order */ |
| 4529 #define SQLITE_ANY 5 /* Deprecated */ |
| 4530 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ |
| 4531 |
| 4532 /* |
| 4533 ** CAPI3REF: Function Flags |
| 4534 ** |
| 4535 ** These constants may be ORed together with the |
| 4536 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument |
| 4537 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or |
| 4538 ** [sqlite3_create_function_v2()]. |
| 4539 */ |
| 4540 #define SQLITE_DETERMINISTIC 0x800 |
| 4541 |
| 4542 /* |
| 4543 ** CAPI3REF: Deprecated Functions |
| 4544 ** DEPRECATED |
| 4545 ** |
| 4546 ** These functions are [deprecated]. In order to maintain |
| 4547 ** backwards compatibility with older code, these functions continue |
| 4548 ** to be supported. However, new applications should avoid |
| 4549 ** the use of these functions. To encourage programmers to avoid |
| 4550 ** these functions, we will not explain what they do. |
| 4551 */ |
| 4552 #ifndef SQLITE_OMIT_DEPRECATED |
| 4553 SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); |
| 4554 SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); |
| 4555 SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); |
| 4556 SQLITE_DEPRECATED int sqlite3_global_recover(void); |
| 4557 SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); |
| 4558 SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), |
| 4559 void*,sqlite3_int64); |
| 4560 #endif |
| 4561 |
| 4562 /* |
| 4563 ** CAPI3REF: Obtaining SQL Values |
| 4564 ** METHOD: sqlite3_value |
| 4565 ** |
| 4566 ** The C-language implementation of SQL functions and aggregates uses |
| 4567 ** this set of interface routines to access the parameter values on |
| 4568 ** the function or aggregate. |
| 4569 ** |
| 4570 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters |
| 4571 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] |
| 4572 ** define callbacks that implement the SQL functions and aggregates. |
| 4573 ** The 3rd parameter to these callbacks is an array of pointers to |
| 4574 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for |
| 4575 ** each parameter to the SQL function. These routines are used to |
| 4576 ** extract values from the [sqlite3_value] objects. |
| 4577 ** |
| 4578 ** These routines work only with [protected sqlite3_value] objects. |
| 4579 ** Any attempt to use these routines on an [unprotected sqlite3_value] |
| 4580 ** object results in undefined behavior. |
| 4581 ** |
| 4582 ** ^These routines work just like the corresponding [column access functions] |
| 4583 ** except that these routines take a single [protected sqlite3_value] object |
| 4584 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. |
| 4585 ** |
| 4586 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string |
| 4587 ** in the native byte-order of the host machine. ^The |
| 4588 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces |
| 4589 ** extract UTF-16 strings as big-endian and little-endian respectively. |
| 4590 ** |
| 4591 ** ^(The sqlite3_value_numeric_type() interface attempts to apply |
| 4592 ** numeric affinity to the value. This means that an attempt is |
| 4593 ** made to convert the value to an integer or floating point. If |
| 4594 ** such a conversion is possible without loss of information (in other |
| 4595 ** words, if the value is a string that looks like a number) |
| 4596 ** then the conversion is performed. Otherwise no conversion occurs. |
| 4597 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ |
| 4598 ** |
| 4599 ** Please pay particular attention to the fact that the pointer returned |
| 4600 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or |
| 4601 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to |
| 4602 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], |
| 4603 ** or [sqlite3_value_text16()]. |
| 4604 ** |
| 4605 ** These routines must be called from the same thread as |
| 4606 ** the SQL function that supplied the [sqlite3_value*] parameters. |
| 4607 */ |
| 4608 const void *sqlite3_value_blob(sqlite3_value*); |
| 4609 int sqlite3_value_bytes(sqlite3_value*); |
| 4610 int sqlite3_value_bytes16(sqlite3_value*); |
| 4611 double sqlite3_value_double(sqlite3_value*); |
| 4612 int sqlite3_value_int(sqlite3_value*); |
| 4613 sqlite3_int64 sqlite3_value_int64(sqlite3_value*); |
| 4614 const unsigned char *sqlite3_value_text(sqlite3_value*); |
| 4615 const void *sqlite3_value_text16(sqlite3_value*); |
| 4616 const void *sqlite3_value_text16le(sqlite3_value*); |
| 4617 const void *sqlite3_value_text16be(sqlite3_value*); |
| 4618 int sqlite3_value_type(sqlite3_value*); |
| 4619 int sqlite3_value_numeric_type(sqlite3_value*); |
| 4620 |
| 4621 /* |
| 4622 ** CAPI3REF: Finding The Subtype Of SQL Values |
| 4623 ** METHOD: sqlite3_value |
| 4624 ** |
| 4625 ** The sqlite3_value_subtype(V) function returns the subtype for |
| 4626 ** an [application-defined SQL function] argument V. The subtype |
| 4627 ** information can be used to pass a limited amount of context from |
| 4628 ** one SQL function to another. Use the [sqlite3_result_subtype()] |
| 4629 ** routine to set the subtype for the return value of an SQL function. |
| 4630 ** |
| 4631 ** SQLite makes no use of subtype itself. It merely passes the subtype |
| 4632 ** from the result of one [application-defined SQL function] into the |
| 4633 ** input of another. |
| 4634 */ |
| 4635 unsigned int sqlite3_value_subtype(sqlite3_value*); |
| 4636 |
| 4637 /* |
| 4638 ** CAPI3REF: Copy And Free SQL Values |
| 4639 ** METHOD: sqlite3_value |
| 4640 ** |
| 4641 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] |
| 4642 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned |
| 4643 ** is a [protected sqlite3_value] object even if the input is not. |
| 4644 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a |
| 4645 ** memory allocation fails. |
| 4646 ** |
| 4647 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object |
| 4648 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer |
| 4649 ** then sqlite3_value_free(V) is a harmless no-op. |
| 4650 */ |
| 4651 sqlite3_value *sqlite3_value_dup(const sqlite3_value*); |
| 4652 void sqlite3_value_free(sqlite3_value*); |
| 4653 |
| 4654 /* |
| 4655 ** CAPI3REF: Obtain Aggregate Function Context |
| 4656 ** METHOD: sqlite3_context |
| 4657 ** |
| 4658 ** Implementations of aggregate SQL functions use this |
| 4659 ** routine to allocate memory for storing their state. |
| 4660 ** |
| 4661 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called |
| 4662 ** for a particular aggregate function, SQLite |
| 4663 ** allocates N of memory, zeroes out that memory, and returns a pointer |
| 4664 ** to the new memory. ^On second and subsequent calls to |
| 4665 ** sqlite3_aggregate_context() for the same aggregate function instance, |
| 4666 ** the same buffer is returned. Sqlite3_aggregate_context() is normally |
| 4667 ** called once for each invocation of the xStep callback and then one |
| 4668 ** last time when the xFinal callback is invoked. ^(When no rows match |
| 4669 ** an aggregate query, the xStep() callback of the aggregate function |
| 4670 ** implementation is never called and xFinal() is called exactly once. |
| 4671 ** In those cases, sqlite3_aggregate_context() might be called for the |
| 4672 ** first time from within xFinal().)^ |
| 4673 ** |
| 4674 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer |
| 4675 ** when first called if N is less than or equal to zero or if a memory |
| 4676 ** allocate error occurs. |
| 4677 ** |
| 4678 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is |
| 4679 ** determined by the N parameter on first successful call. Changing the |
| 4680 ** value of N in subsequent call to sqlite3_aggregate_context() within |
| 4681 ** the same aggregate function instance will not resize the memory |
| 4682 ** allocation.)^ Within the xFinal callback, it is customary to set |
| 4683 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no |
| 4684 ** pointless memory allocations occur. |
| 4685 ** |
| 4686 ** ^SQLite automatically frees the memory allocated by |
| 4687 ** sqlite3_aggregate_context() when the aggregate query concludes. |
| 4688 ** |
| 4689 ** The first parameter must be a copy of the |
| 4690 ** [sqlite3_context | SQL function context] that is the first parameter |
| 4691 ** to the xStep or xFinal callback routine that implements the aggregate |
| 4692 ** function. |
| 4693 ** |
| 4694 ** This routine must be called from the same thread in which |
| 4695 ** the aggregate SQL function is running. |
| 4696 */ |
| 4697 void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); |
| 4698 |
| 4699 /* |
| 4700 ** CAPI3REF: User Data For Functions |
| 4701 ** METHOD: sqlite3_context |
| 4702 ** |
| 4703 ** ^The sqlite3_user_data() interface returns a copy of |
| 4704 ** the pointer that was the pUserData parameter (the 5th parameter) |
| 4705 ** of the [sqlite3_create_function()] |
| 4706 ** and [sqlite3_create_function16()] routines that originally |
| 4707 ** registered the application defined function. |
| 4708 ** |
| 4709 ** This routine must be called from the same thread in which |
| 4710 ** the application-defined function is running. |
| 4711 */ |
| 4712 void *sqlite3_user_data(sqlite3_context*); |
| 4713 |
| 4714 /* |
| 4715 ** CAPI3REF: Database Connection For Functions |
| 4716 ** METHOD: sqlite3_context |
| 4717 ** |
| 4718 ** ^The sqlite3_context_db_handle() interface returns a copy of |
| 4719 ** the pointer to the [database connection] (the 1st parameter) |
| 4720 ** of the [sqlite3_create_function()] |
| 4721 ** and [sqlite3_create_function16()] routines that originally |
| 4722 ** registered the application defined function. |
| 4723 */ |
| 4724 sqlite3 *sqlite3_context_db_handle(sqlite3_context*); |
| 4725 |
| 4726 /* |
| 4727 ** CAPI3REF: Function Auxiliary Data |
| 4728 ** METHOD: sqlite3_context |
| 4729 ** |
| 4730 ** These functions may be used by (non-aggregate) SQL functions to |
| 4731 ** associate metadata with argument values. If the same value is passed to |
| 4732 ** multiple invocations of the same SQL function during query execution, under |
| 4733 ** some circumstances the associated metadata may be preserved. An example |
| 4734 ** of where this might be useful is in a regular-expression matching |
| 4735 ** function. The compiled version of the regular expression can be stored as |
| 4736 ** metadata associated with the pattern string. |
| 4737 ** Then as long as the pattern string remains the same, |
| 4738 ** the compiled regular expression can be reused on multiple |
| 4739 ** invocations of the same function. |
| 4740 ** |
| 4741 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata |
| 4742 ** associated by the sqlite3_set_auxdata() function with the Nth argument |
| 4743 ** value to the application-defined function. ^If there is no metadata |
| 4744 ** associated with the function argument, this sqlite3_get_auxdata() interface |
| 4745 ** returns a NULL pointer. |
| 4746 ** |
| 4747 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th |
| 4748 ** argument of the application-defined function. ^Subsequent |
| 4749 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent |
| 4750 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or |
| 4751 ** NULL if the metadata has been discarded. |
| 4752 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, |
| 4753 ** SQLite will invoke the destructor function X with parameter P exactly |
| 4754 ** once, when the metadata is discarded. |
| 4755 ** SQLite is free to discard the metadata at any time, including: <ul> |
| 4756 ** <li> ^(when the corresponding function parameter changes)^, or |
| 4757 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the |
| 4758 ** SQL statement)^, or |
| 4759 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same |
| 4760 ** parameter)^, or |
| 4761 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory |
| 4762 ** allocation error occurs.)^ </ul> |
| 4763 ** |
| 4764 ** Note the last bullet in particular. The destructor X in |
| 4765 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the |
| 4766 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() |
| 4767 ** should be called near the end of the function implementation and the |
| 4768 ** function implementation should not make any use of P after |
| 4769 ** sqlite3_set_auxdata() has been called. |
| 4770 ** |
| 4771 ** ^(In practice, metadata is preserved between function calls for |
| 4772 ** function parameters that are compile-time constants, including literal |
| 4773 ** values and [parameters] and expressions composed from the same.)^ |
| 4774 ** |
| 4775 ** These routines must be called from the same thread in which |
| 4776 ** the SQL function is running. |
| 4777 */ |
| 4778 void *sqlite3_get_auxdata(sqlite3_context*, int N); |
| 4779 void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); |
| 4780 |
| 4781 |
| 4782 /* |
| 4783 ** CAPI3REF: Constants Defining Special Destructor Behavior |
| 4784 ** |
| 4785 ** These are special values for the destructor that is passed in as the |
| 4786 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor |
| 4787 ** argument is SQLITE_STATIC, it means that the content pointer is constant |
| 4788 ** and will never change. It does not need to be destroyed. ^The |
| 4789 ** SQLITE_TRANSIENT value means that the content will likely change in |
| 4790 ** the near future and that SQLite should make its own private copy of |
| 4791 ** the content before returning. |
| 4792 ** |
| 4793 ** The typedef is necessary to work around problems in certain |
| 4794 ** C++ compilers. |
| 4795 */ |
| 4796 typedef void (*sqlite3_destructor_type)(void*); |
| 4797 #define SQLITE_STATIC ((sqlite3_destructor_type)0) |
| 4798 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) |
| 4799 |
| 4800 /* |
| 4801 ** CAPI3REF: Setting The Result Of An SQL Function |
| 4802 ** METHOD: sqlite3_context |
| 4803 ** |
| 4804 ** These routines are used by the xFunc or xFinal callbacks that |
| 4805 ** implement SQL functions and aggregates. See |
| 4806 ** [sqlite3_create_function()] and [sqlite3_create_function16()] |
| 4807 ** for additional information. |
| 4808 ** |
| 4809 ** These functions work very much like the [parameter binding] family of |
| 4810 ** functions used to bind values to host parameters in prepared statements. |
| 4811 ** Refer to the [SQL parameter] documentation for additional information. |
| 4812 ** |
| 4813 ** ^The sqlite3_result_blob() interface sets the result from |
| 4814 ** an application-defined function to be the BLOB whose content is pointed |
| 4815 ** to by the second parameter and which is N bytes long where N is the |
| 4816 ** third parameter. |
| 4817 ** |
| 4818 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) |
| 4819 ** interfaces set the result of the application-defined function to be |
| 4820 ** a BLOB containing all zero bytes and N bytes in size. |
| 4821 ** |
| 4822 ** ^The sqlite3_result_double() interface sets the result from |
| 4823 ** an application-defined function to be a floating point value specified |
| 4824 ** by its 2nd argument. |
| 4825 ** |
| 4826 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions |
| 4827 ** cause the implemented SQL function to throw an exception. |
| 4828 ** ^SQLite uses the string pointed to by the |
| 4829 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() |
| 4830 ** as the text of an error message. ^SQLite interprets the error |
| 4831 ** message string from sqlite3_result_error() as UTF-8. ^SQLite |
| 4832 ** interprets the string from sqlite3_result_error16() as UTF-16 in native |
| 4833 ** byte order. ^If the third parameter to sqlite3_result_error() |
| 4834 ** or sqlite3_result_error16() is negative then SQLite takes as the error |
| 4835 ** message all text up through the first zero character. |
| 4836 ** ^If the third parameter to sqlite3_result_error() or |
| 4837 ** sqlite3_result_error16() is non-negative then SQLite takes that many |
| 4838 ** bytes (not characters) from the 2nd parameter as the error message. |
| 4839 ** ^The sqlite3_result_error() and sqlite3_result_error16() |
| 4840 ** routines make a private copy of the error message text before |
| 4841 ** they return. Hence, the calling function can deallocate or |
| 4842 ** modify the text after they return without harm. |
| 4843 ** ^The sqlite3_result_error_code() function changes the error code |
| 4844 ** returned by SQLite as a result of an error in a function. ^By default, |
| 4845 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() |
| 4846 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. |
| 4847 ** |
| 4848 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an |
| 4849 ** error indicating that a string or BLOB is too long to represent. |
| 4850 ** |
| 4851 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an |
| 4852 ** error indicating that a memory allocation failed. |
| 4853 ** |
| 4854 ** ^The sqlite3_result_int() interface sets the return value |
| 4855 ** of the application-defined function to be the 32-bit signed integer |
| 4856 ** value given in the 2nd argument. |
| 4857 ** ^The sqlite3_result_int64() interface sets the return value |
| 4858 ** of the application-defined function to be the 64-bit signed integer |
| 4859 ** value given in the 2nd argument. |
| 4860 ** |
| 4861 ** ^The sqlite3_result_null() interface sets the return value |
| 4862 ** of the application-defined function to be NULL. |
| 4863 ** |
| 4864 ** ^The sqlite3_result_text(), sqlite3_result_text16(), |
| 4865 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces |
| 4866 ** set the return value of the application-defined function to be |
| 4867 ** a text string which is represented as UTF-8, UTF-16 native byte order, |
| 4868 ** UTF-16 little endian, or UTF-16 big endian, respectively. |
| 4869 ** ^The sqlite3_result_text64() interface sets the return value of an |
| 4870 ** application-defined function to be a text string in an encoding |
| 4871 ** specified by the fifth (and last) parameter, which must be one |
| 4872 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. |
| 4873 ** ^SQLite takes the text result from the application from |
| 4874 ** the 2nd parameter of the sqlite3_result_text* interfaces. |
| 4875 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces |
| 4876 ** is negative, then SQLite takes result text from the 2nd parameter |
| 4877 ** through the first zero character. |
| 4878 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces |
| 4879 ** is non-negative, then as many bytes (not characters) of the text |
| 4880 ** pointed to by the 2nd parameter are taken as the application-defined |
| 4881 ** function result. If the 3rd parameter is non-negative, then it |
| 4882 ** must be the byte offset into the string where the NUL terminator would |
| 4883 ** appear if the string where NUL terminated. If any NUL characters occur |
| 4884 ** in the string at a byte offset that is less than the value of the 3rd |
| 4885 ** parameter, then the resulting string will contain embedded NULs and the |
| 4886 ** result of expressions operating on strings with embedded NULs is undefined. |
| 4887 ** ^If the 4th parameter to the sqlite3_result_text* interfaces |
| 4888 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that |
| 4889 ** function as the destructor on the text or BLOB result when it has |
| 4890 ** finished using that result. |
| 4891 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to |
| 4892 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite |
| 4893 ** assumes that the text or BLOB result is in constant space and does not |
| 4894 ** copy the content of the parameter nor call a destructor on the content |
| 4895 ** when it has finished using that result. |
| 4896 ** ^If the 4th parameter to the sqlite3_result_text* interfaces |
| 4897 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT |
| 4898 ** then SQLite makes a copy of the result into space obtained from |
| 4899 ** from [sqlite3_malloc()] before it returns. |
| 4900 ** |
| 4901 ** ^The sqlite3_result_value() interface sets the result of |
| 4902 ** the application-defined function to be a copy of the |
| 4903 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The |
| 4904 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] |
| 4905 ** so that the [sqlite3_value] specified in the parameter may change or |
| 4906 ** be deallocated after sqlite3_result_value() returns without harm. |
| 4907 ** ^A [protected sqlite3_value] object may always be used where an |
| 4908 ** [unprotected sqlite3_value] object is required, so either |
| 4909 ** kind of [sqlite3_value] object can be used with this interface. |
| 4910 ** |
| 4911 ** If these routines are called from within the different thread |
| 4912 ** than the one containing the application-defined function that received |
| 4913 ** the [sqlite3_context] pointer, the results are undefined. |
| 4914 */ |
| 4915 void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); |
| 4916 void sqlite3_result_blob64(sqlite3_context*,const void*, |
| 4917 sqlite3_uint64,void(*)(void*)); |
| 4918 void sqlite3_result_double(sqlite3_context*, double); |
| 4919 void sqlite3_result_error(sqlite3_context*, const char*, int); |
| 4920 void sqlite3_result_error16(sqlite3_context*, const void*, int); |
| 4921 void sqlite3_result_error_toobig(sqlite3_context*); |
| 4922 void sqlite3_result_error_nomem(sqlite3_context*); |
| 4923 void sqlite3_result_error_code(sqlite3_context*, int); |
| 4924 void sqlite3_result_int(sqlite3_context*, int); |
| 4925 void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); |
| 4926 void sqlite3_result_null(sqlite3_context*); |
| 4927 void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); |
| 4928 void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, |
| 4929 void(*)(void*), unsigned char encoding); |
| 4930 void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); |
| 4931 void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); |
| 4932 void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); |
| 4933 void sqlite3_result_value(sqlite3_context*, sqlite3_value*); |
| 4934 void sqlite3_result_zeroblob(sqlite3_context*, int n); |
| 4935 int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); |
| 4936 |
| 4937 |
| 4938 /* |
| 4939 ** CAPI3REF: Setting The Subtype Of An SQL Function |
| 4940 ** METHOD: sqlite3_context |
| 4941 ** |
| 4942 ** The sqlite3_result_subtype(C,T) function causes the subtype of |
| 4943 ** the result from the [application-defined SQL function] with |
| 4944 ** [sqlite3_context] C to be the value T. Only the lower 8 bits |
| 4945 ** of the subtype T are preserved in current versions of SQLite; |
| 4946 ** higher order bits are discarded. |
| 4947 ** The number of subtype bytes preserved by SQLite might increase |
| 4948 ** in future releases of SQLite. |
| 4949 */ |
| 4950 void sqlite3_result_subtype(sqlite3_context*,unsigned int); |
| 4951 |
| 4952 /* |
| 4953 ** CAPI3REF: Define New Collating Sequences |
| 4954 ** METHOD: sqlite3 |
| 4955 ** |
| 4956 ** ^These functions add, remove, or modify a [collation] associated |
| 4957 ** with the [database connection] specified as the first argument. |
| 4958 ** |
| 4959 ** ^The name of the collation is a UTF-8 string |
| 4960 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() |
| 4961 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). |
| 4962 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are |
| 4963 ** considered to be the same name. |
| 4964 ** |
| 4965 ** ^(The third argument (eTextRep) must be one of the constants: |
| 4966 ** <ul> |
| 4967 ** <li> [SQLITE_UTF8], |
| 4968 ** <li> [SQLITE_UTF16LE], |
| 4969 ** <li> [SQLITE_UTF16BE], |
| 4970 ** <li> [SQLITE_UTF16], or |
| 4971 ** <li> [SQLITE_UTF16_ALIGNED]. |
| 4972 ** </ul>)^ |
| 4973 ** ^The eTextRep argument determines the encoding of strings passed |
| 4974 ** to the collating function callback, xCallback. |
| 4975 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep |
| 4976 ** force strings to be UTF16 with native byte order. |
| 4977 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin |
| 4978 ** on an even byte address. |
| 4979 ** |
| 4980 ** ^The fourth argument, pArg, is an application data pointer that is passed |
| 4981 ** through as the first argument to the collating function callback. |
| 4982 ** |
| 4983 ** ^The fifth argument, xCallback, is a pointer to the collating function. |
| 4984 ** ^Multiple collating functions can be registered using the same name but |
| 4985 ** with different eTextRep parameters and SQLite will use whichever |
| 4986 ** function requires the least amount of data transformation. |
| 4987 ** ^If the xCallback argument is NULL then the collating function is |
| 4988 ** deleted. ^When all collating functions having the same name are deleted, |
| 4989 ** that collation is no longer usable. |
| 4990 ** |
| 4991 ** ^The collating function callback is invoked with a copy of the pArg |
| 4992 ** application data pointer and with two strings in the encoding specified |
| 4993 ** by the eTextRep argument. The collating function must return an |
| 4994 ** integer that is negative, zero, or positive |
| 4995 ** if the first string is less than, equal to, or greater than the second, |
| 4996 ** respectively. A collating function must always return the same answer |
| 4997 ** given the same inputs. If two or more collating functions are registered |
| 4998 ** to the same collation name (using different eTextRep values) then all |
| 4999 ** must give an equivalent answer when invoked with equivalent strings. |
| 5000 ** The collating function must obey the following properties for all |
| 5001 ** strings A, B, and C: |
| 5002 ** |
| 5003 ** <ol> |
| 5004 ** <li> If A==B then B==A. |
| 5005 ** <li> If A==B and B==C then A==C. |
| 5006 ** <li> If A<B THEN B>A. |
| 5007 ** <li> If A<B and B<C then A<C. |
| 5008 ** </ol> |
| 5009 ** |
| 5010 ** If a collating function fails any of the above constraints and that |
| 5011 ** collating function is registered and used, then the behavior of SQLite |
| 5012 ** is undefined. |
| 5013 ** |
| 5014 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() |
| 5015 ** with the addition that the xDestroy callback is invoked on pArg when |
| 5016 ** the collating function is deleted. |
| 5017 ** ^Collating functions are deleted when they are overridden by later |
| 5018 ** calls to the collation creation functions or when the |
| 5019 ** [database connection] is closed using [sqlite3_close()]. |
| 5020 ** |
| 5021 ** ^The xDestroy callback is <u>not</u> called if the |
| 5022 ** sqlite3_create_collation_v2() function fails. Applications that invoke |
| 5023 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should |
| 5024 ** check the return code and dispose of the application data pointer |
| 5025 ** themselves rather than expecting SQLite to deal with it for them. |
| 5026 ** This is different from every other SQLite interface. The inconsistency |
| 5027 ** is unfortunate but cannot be changed without breaking backwards |
| 5028 ** compatibility. |
| 5029 ** |
| 5030 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. |
| 5031 */ |
| 5032 int sqlite3_create_collation( |
| 5033 sqlite3*, |
| 5034 const char *zName, |
| 5035 int eTextRep, |
| 5036 void *pArg, |
| 5037 int(*xCompare)(void*,int,const void*,int,const void*) |
| 5038 ); |
| 5039 int sqlite3_create_collation_v2( |
| 5040 sqlite3*, |
| 5041 const char *zName, |
| 5042 int eTextRep, |
| 5043 void *pArg, |
| 5044 int(*xCompare)(void*,int,const void*,int,const void*), |
| 5045 void(*xDestroy)(void*) |
| 5046 ); |
| 5047 int sqlite3_create_collation16( |
| 5048 sqlite3*, |
| 5049 const void *zName, |
| 5050 int eTextRep, |
| 5051 void *pArg, |
| 5052 int(*xCompare)(void*,int,const void*,int,const void*) |
| 5053 ); |
| 5054 |
| 5055 /* |
| 5056 ** CAPI3REF: Collation Needed Callbacks |
| 5057 ** METHOD: sqlite3 |
| 5058 ** |
| 5059 ** ^To avoid having to register all collation sequences before a database |
| 5060 ** can be used, a single callback function may be registered with the |
| 5061 ** [database connection] to be invoked whenever an undefined collation |
| 5062 ** sequence is required. |
| 5063 ** |
| 5064 ** ^If the function is registered using the sqlite3_collation_needed() API, |
| 5065 ** then it is passed the names of undefined collation sequences as strings |
| 5066 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, |
| 5067 ** the names are passed as UTF-16 in machine native byte order. |
| 5068 ** ^A call to either function replaces the existing collation-needed callback. |
| 5069 ** |
| 5070 ** ^(When the callback is invoked, the first argument passed is a copy |
| 5071 ** of the second argument to sqlite3_collation_needed() or |
| 5072 ** sqlite3_collation_needed16(). The second argument is the database |
| 5073 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], |
| 5074 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation |
| 5075 ** sequence function required. The fourth parameter is the name of the |
| 5076 ** required collation sequence.)^ |
| 5077 ** |
| 5078 ** The callback function should register the desired collation using |
| 5079 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or |
| 5080 ** [sqlite3_create_collation_v2()]. |
| 5081 */ |
| 5082 int sqlite3_collation_needed( |
| 5083 sqlite3*, |
| 5084 void*, |
| 5085 void(*)(void*,sqlite3*,int eTextRep,const char*) |
| 5086 ); |
| 5087 int sqlite3_collation_needed16( |
| 5088 sqlite3*, |
| 5089 void*, |
| 5090 void(*)(void*,sqlite3*,int eTextRep,const void*) |
| 5091 ); |
| 5092 |
| 5093 #ifdef SQLITE_HAS_CODEC |
| 5094 /* |
| 5095 ** Specify the key for an encrypted database. This routine should be |
| 5096 ** called right after sqlite3_open(). |
| 5097 ** |
| 5098 ** The code to implement this API is not available in the public release |
| 5099 ** of SQLite. |
| 5100 */ |
| 5101 int sqlite3_key( |
| 5102 sqlite3 *db, /* Database to be rekeyed */ |
| 5103 const void *pKey, int nKey /* The key */ |
| 5104 ); |
| 5105 int sqlite3_key_v2( |
| 5106 sqlite3 *db, /* Database to be rekeyed */ |
| 5107 const char *zDbName, /* Name of the database */ |
| 5108 const void *pKey, int nKey /* The key */ |
| 5109 ); |
| 5110 |
| 5111 /* |
| 5112 ** Change the key on an open database. If the current database is not |
| 5113 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the |
| 5114 ** database is decrypted. |
| 5115 ** |
| 5116 ** The code to implement this API is not available in the public release |
| 5117 ** of SQLite. |
| 5118 */ |
| 5119 int sqlite3_rekey( |
| 5120 sqlite3 *db, /* Database to be rekeyed */ |
| 5121 const void *pKey, int nKey /* The new key */ |
| 5122 ); |
| 5123 int sqlite3_rekey_v2( |
| 5124 sqlite3 *db, /* Database to be rekeyed */ |
| 5125 const char *zDbName, /* Name of the database */ |
| 5126 const void *pKey, int nKey /* The new key */ |
| 5127 ); |
| 5128 |
| 5129 /* |
| 5130 ** Specify the activation key for a SEE database. Unless |
| 5131 ** activated, none of the SEE routines will work. |
| 5132 */ |
| 5133 void sqlite3_activate_see( |
| 5134 const char *zPassPhrase /* Activation phrase */ |
| 5135 ); |
| 5136 #endif |
| 5137 |
| 5138 #ifdef SQLITE_ENABLE_CEROD |
| 5139 /* |
| 5140 ** Specify the activation key for a CEROD database. Unless |
| 5141 ** activated, none of the CEROD routines will work. |
| 5142 */ |
| 5143 void sqlite3_activate_cerod( |
| 5144 const char *zPassPhrase /* Activation phrase */ |
| 5145 ); |
| 5146 #endif |
| 5147 |
| 5148 /* |
| 5149 ** CAPI3REF: Suspend Execution For A Short Time |
| 5150 ** |
| 5151 ** The sqlite3_sleep() function causes the current thread to suspend execution |
| 5152 ** for at least a number of milliseconds specified in its parameter. |
| 5153 ** |
| 5154 ** If the operating system does not support sleep requests with |
| 5155 ** millisecond time resolution, then the time will be rounded up to |
| 5156 ** the nearest second. The number of milliseconds of sleep actually |
| 5157 ** requested from the operating system is returned. |
| 5158 ** |
| 5159 ** ^SQLite implements this interface by calling the xSleep() |
| 5160 ** method of the default [sqlite3_vfs] object. If the xSleep() method |
| 5161 ** of the default VFS is not implemented correctly, or not implemented at |
| 5162 ** all, then the behavior of sqlite3_sleep() may deviate from the description |
| 5163 ** in the previous paragraphs. |
| 5164 */ |
| 5165 int sqlite3_sleep(int); |
| 5166 |
| 5167 /* |
| 5168 ** CAPI3REF: Name Of The Folder Holding Temporary Files |
| 5169 ** |
| 5170 ** ^(If this global variable is made to point to a string which is |
| 5171 ** the name of a folder (a.k.a. directory), then all temporary files |
| 5172 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] |
| 5173 ** will be placed in that directory.)^ ^If this variable |
| 5174 ** is a NULL pointer, then SQLite performs a search for an appropriate |
| 5175 ** temporary file directory. |
| 5176 ** |
| 5177 ** Applications are strongly discouraged from using this global variable. |
| 5178 ** It is required to set a temporary folder on Windows Runtime (WinRT). |
| 5179 ** But for all other platforms, it is highly recommended that applications |
| 5180 ** neither read nor write this variable. This global variable is a relic |
| 5181 ** that exists for backwards compatibility of legacy applications and should |
| 5182 ** be avoided in new projects. |
| 5183 ** |
| 5184 ** It is not safe to read or modify this variable in more than one |
| 5185 ** thread at a time. It is not safe to read or modify this variable |
| 5186 ** if a [database connection] is being used at the same time in a separate |
| 5187 ** thread. |
| 5188 ** It is intended that this variable be set once |
| 5189 ** as part of process initialization and before any SQLite interface |
| 5190 ** routines have been called and that this variable remain unchanged |
| 5191 ** thereafter. |
| 5192 ** |
| 5193 ** ^The [temp_store_directory pragma] may modify this variable and cause |
| 5194 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, |
| 5195 ** the [temp_store_directory pragma] always assumes that any string |
| 5196 ** that this variable points to is held in memory obtained from |
| 5197 ** [sqlite3_malloc] and the pragma may attempt to free that memory |
| 5198 ** using [sqlite3_free]. |
| 5199 ** Hence, if this variable is modified directly, either it should be |
| 5200 ** made NULL or made to point to memory obtained from [sqlite3_malloc] |
| 5201 ** or else the use of the [temp_store_directory pragma] should be avoided. |
| 5202 ** Except when requested by the [temp_store_directory pragma], SQLite |
| 5203 ** does not free the memory that sqlite3_temp_directory points to. If |
| 5204 ** the application wants that memory to be freed, it must do |
| 5205 ** so itself, taking care to only do so after all [database connection] |
| 5206 ** objects have been destroyed. |
| 5207 ** |
| 5208 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set |
| 5209 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various |
| 5210 ** features that require the use of temporary files may fail. Here is an |
| 5211 ** example of how to do this using C++ with the Windows Runtime: |
| 5212 ** |
| 5213 ** <blockquote><pre> |
| 5214 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> |
| 5215 ** TemporaryFolder->Path->Data(); |
| 5216 ** char zPathBuf[MAX_PATH + 1]; |
| 5217 ** memset(zPathBuf, 0, sizeof(zPathBuf)); |
| 5218 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), |
| 5219 ** NULL, NULL); |
| 5220 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); |
| 5221 ** </pre></blockquote> |
| 5222 */ |
| 5223 SQLITE_EXTERN char *sqlite3_temp_directory; |
| 5224 |
| 5225 /* |
| 5226 ** CAPI3REF: Name Of The Folder Holding Database Files |
| 5227 ** |
| 5228 ** ^(If this global variable is made to point to a string which is |
| 5229 ** the name of a folder (a.k.a. directory), then all database files |
| 5230 ** specified with a relative pathname and created or accessed by |
| 5231 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed |
| 5232 ** to be relative to that directory.)^ ^If this variable is a NULL |
| 5233 ** pointer, then SQLite assumes that all database files specified |
| 5234 ** with a relative pathname are relative to the current directory |
| 5235 ** for the process. Only the windows VFS makes use of this global |
| 5236 ** variable; it is ignored by the unix VFS. |
| 5237 ** |
| 5238 ** Changing the value of this variable while a database connection is |
| 5239 ** open can result in a corrupt database. |
| 5240 ** |
| 5241 ** It is not safe to read or modify this variable in more than one |
| 5242 ** thread at a time. It is not safe to read or modify this variable |
| 5243 ** if a [database connection] is being used at the same time in a separate |
| 5244 ** thread. |
| 5245 ** It is intended that this variable be set once |
| 5246 ** as part of process initialization and before any SQLite interface |
| 5247 ** routines have been called and that this variable remain unchanged |
| 5248 ** thereafter. |
| 5249 ** |
| 5250 ** ^The [data_store_directory pragma] may modify this variable and cause |
| 5251 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, |
| 5252 ** the [data_store_directory pragma] always assumes that any string |
| 5253 ** that this variable points to is held in memory obtained from |
| 5254 ** [sqlite3_malloc] and the pragma may attempt to free that memory |
| 5255 ** using [sqlite3_free]. |
| 5256 ** Hence, if this variable is modified directly, either it should be |
| 5257 ** made NULL or made to point to memory obtained from [sqlite3_malloc] |
| 5258 ** or else the use of the [data_store_directory pragma] should be avoided. |
| 5259 */ |
| 5260 SQLITE_EXTERN char *sqlite3_data_directory; |
| 5261 |
| 5262 /* |
| 5263 ** CAPI3REF: Test For Auto-Commit Mode |
| 5264 ** KEYWORDS: {autocommit mode} |
| 5265 ** METHOD: sqlite3 |
| 5266 ** |
| 5267 ** ^The sqlite3_get_autocommit() interface returns non-zero or |
| 5268 ** zero if the given database connection is or is not in autocommit mode, |
| 5269 ** respectively. ^Autocommit mode is on by default. |
| 5270 ** ^Autocommit mode is disabled by a [BEGIN] statement. |
| 5271 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. |
| 5272 ** |
| 5273 ** If certain kinds of errors occur on a statement within a multi-statement |
| 5274 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], |
| 5275 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the |
| 5276 ** transaction might be rolled back automatically. The only way to |
| 5277 ** find out whether SQLite automatically rolled back the transaction after |
| 5278 ** an error is to use this function. |
| 5279 ** |
| 5280 ** If another thread changes the autocommit status of the database |
| 5281 ** connection while this routine is running, then the return value |
| 5282 ** is undefined. |
| 5283 */ |
| 5284 int sqlite3_get_autocommit(sqlite3*); |
| 5285 |
| 5286 /* |
| 5287 ** CAPI3REF: Find The Database Handle Of A Prepared Statement |
| 5288 ** METHOD: sqlite3_stmt |
| 5289 ** |
| 5290 ** ^The sqlite3_db_handle interface returns the [database connection] handle |
| 5291 ** to which a [prepared statement] belongs. ^The [database connection] |
| 5292 ** returned by sqlite3_db_handle is the same [database connection] |
| 5293 ** that was the first argument |
| 5294 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to |
| 5295 ** create the statement in the first place. |
| 5296 */ |
| 5297 sqlite3 *sqlite3_db_handle(sqlite3_stmt*); |
| 5298 |
| 5299 /* |
| 5300 ** CAPI3REF: Return The Filename For A Database Connection |
| 5301 ** METHOD: sqlite3 |
| 5302 ** |
| 5303 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename |
| 5304 ** associated with database N of connection D. ^The main database file |
| 5305 ** has the name "main". If there is no attached database N on the database |
| 5306 ** connection D, or if database N is a temporary or in-memory database, then |
| 5307 ** a NULL pointer is returned. |
| 5308 ** |
| 5309 ** ^The filename returned by this function is the output of the |
| 5310 ** xFullPathname method of the [VFS]. ^In other words, the filename |
| 5311 ** will be an absolute pathname, even if the filename used |
| 5312 ** to open the database originally was a URI or relative pathname. |
| 5313 */ |
| 5314 const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); |
| 5315 |
| 5316 /* |
| 5317 ** CAPI3REF: Determine if a database is read-only |
| 5318 ** METHOD: sqlite3 |
| 5319 ** |
| 5320 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N |
| 5321 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not |
| 5322 ** the name of a database on connection D. |
| 5323 */ |
| 5324 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); |
| 5325 |
| 5326 /* |
| 5327 ** CAPI3REF: Find the next prepared statement |
| 5328 ** METHOD: sqlite3 |
| 5329 ** |
| 5330 ** ^This interface returns a pointer to the next [prepared statement] after |
| 5331 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL |
| 5332 ** then this interface returns a pointer to the first prepared statement |
| 5333 ** associated with the database connection pDb. ^If no prepared statement |
| 5334 ** satisfies the conditions of this routine, it returns NULL. |
| 5335 ** |
| 5336 ** The [database connection] pointer D in a call to |
| 5337 ** [sqlite3_next_stmt(D,S)] must refer to an open database |
| 5338 ** connection and in particular must not be a NULL pointer. |
| 5339 */ |
| 5340 sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); |
| 5341 |
| 5342 /* |
| 5343 ** CAPI3REF: Commit And Rollback Notification Callbacks |
| 5344 ** METHOD: sqlite3 |
| 5345 ** |
| 5346 ** ^The sqlite3_commit_hook() interface registers a callback |
| 5347 ** function to be invoked whenever a transaction is [COMMIT | committed]. |
| 5348 ** ^Any callback set by a previous call to sqlite3_commit_hook() |
| 5349 ** for the same database connection is overridden. |
| 5350 ** ^The sqlite3_rollback_hook() interface registers a callback |
| 5351 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. |
| 5352 ** ^Any callback set by a previous call to sqlite3_rollback_hook() |
| 5353 ** for the same database connection is overridden. |
| 5354 ** ^The pArg argument is passed through to the callback. |
| 5355 ** ^If the callback on a commit hook function returns non-zero, |
| 5356 ** then the commit is converted into a rollback. |
| 5357 ** |
| 5358 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions |
| 5359 ** return the P argument from the previous call of the same function |
| 5360 ** on the same [database connection] D, or NULL for |
| 5361 ** the first call for each function on D. |
| 5362 ** |
| 5363 ** The commit and rollback hook callbacks are not reentrant. |
| 5364 ** The callback implementation must not do anything that will modify |
| 5365 ** the database connection that invoked the callback. Any actions |
| 5366 ** to modify the database connection must be deferred until after the |
| 5367 ** completion of the [sqlite3_step()] call that triggered the commit |
| 5368 ** or rollback hook in the first place. |
| 5369 ** Note that running any other SQL statements, including SELECT statements, |
| 5370 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify |
| 5371 ** the database connections for the meaning of "modify" in this paragraph. |
| 5372 ** |
| 5373 ** ^Registering a NULL function disables the callback. |
| 5374 ** |
| 5375 ** ^When the commit hook callback routine returns zero, the [COMMIT] |
| 5376 ** operation is allowed to continue normally. ^If the commit hook |
| 5377 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. |
| 5378 ** ^The rollback hook is invoked on a rollback that results from a commit |
| 5379 ** hook returning non-zero, just as it would be with any other rollback. |
| 5380 ** |
| 5381 ** ^For the purposes of this API, a transaction is said to have been |
| 5382 ** rolled back if an explicit "ROLLBACK" statement is executed, or |
| 5383 ** an error or constraint causes an implicit rollback to occur. |
| 5384 ** ^The rollback callback is not invoked if a transaction is |
| 5385 ** automatically rolled back because the database connection is closed. |
| 5386 ** |
| 5387 ** See also the [sqlite3_update_hook()] interface. |
| 5388 */ |
| 5389 void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); |
| 5390 void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); |
| 5391 |
| 5392 /* |
| 5393 ** CAPI3REF: Data Change Notification Callbacks |
| 5394 ** METHOD: sqlite3 |
| 5395 ** |
| 5396 ** ^The sqlite3_update_hook() interface registers a callback function |
| 5397 ** with the [database connection] identified by the first argument |
| 5398 ** to be invoked whenever a row is updated, inserted or deleted in |
| 5399 ** a [rowid table]. |
| 5400 ** ^Any callback set by a previous call to this function |
| 5401 ** for the same database connection is overridden. |
| 5402 ** |
| 5403 ** ^The second argument is a pointer to the function to invoke when a |
| 5404 ** row is updated, inserted or deleted in a rowid table. |
| 5405 ** ^The first argument to the callback is a copy of the third argument |
| 5406 ** to sqlite3_update_hook(). |
| 5407 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], |
| 5408 ** or [SQLITE_UPDATE], depending on the operation that caused the callback |
| 5409 ** to be invoked. |
| 5410 ** ^The third and fourth arguments to the callback contain pointers to the |
| 5411 ** database and table name containing the affected row. |
| 5412 ** ^The final callback parameter is the [rowid] of the row. |
| 5413 ** ^In the case of an update, this is the [rowid] after the update takes place. |
| 5414 ** |
| 5415 ** ^(The update hook is not invoked when internal system tables are |
| 5416 ** modified (i.e. sqlite_master and sqlite_sequence).)^ |
| 5417 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. |
| 5418 ** |
| 5419 ** ^In the current implementation, the update hook |
| 5420 ** is not invoked when conflicting rows are deleted because of an |
| 5421 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook |
| 5422 ** invoked when rows are deleted using the [truncate optimization]. |
| 5423 ** The exceptions defined in this paragraph might change in a future |
| 5424 ** release of SQLite. |
| 5425 ** |
| 5426 ** The update hook implementation must not do anything that will modify |
| 5427 ** the database connection that invoked the update hook. Any actions |
| 5428 ** to modify the database connection must be deferred until after the |
| 5429 ** completion of the [sqlite3_step()] call that triggered the update hook. |
| 5430 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
| 5431 ** database connections for the meaning of "modify" in this paragraph. |
| 5432 ** |
| 5433 ** ^The sqlite3_update_hook(D,C,P) function |
| 5434 ** returns the P argument from the previous call |
| 5435 ** on the same [database connection] D, or NULL for |
| 5436 ** the first call on D. |
| 5437 ** |
| 5438 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], |
| 5439 ** and [sqlite3_preupdate_hook()] interfaces. |
| 5440 */ |
| 5441 void *sqlite3_update_hook( |
| 5442 sqlite3*, |
| 5443 void(*)(void *,int ,char const *,char const *,sqlite3_int64), |
| 5444 void* |
| 5445 ); |
| 5446 |
| 5447 /* |
| 5448 ** CAPI3REF: Enable Or Disable Shared Pager Cache |
| 5449 ** |
| 5450 ** ^(This routine enables or disables the sharing of the database cache |
| 5451 ** and schema data structures between [database connection | connections] |
| 5452 ** to the same database. Sharing is enabled if the argument is true |
| 5453 ** and disabled if the argument is false.)^ |
| 5454 ** |
| 5455 ** ^Cache sharing is enabled and disabled for an entire process. |
| 5456 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). |
| 5457 ** In prior versions of SQLite, |
| 5458 ** sharing was enabled or disabled for each thread separately. |
| 5459 ** |
| 5460 ** ^(The cache sharing mode set by this interface effects all subsequent |
| 5461 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. |
| 5462 ** Existing database connections continue use the sharing mode |
| 5463 ** that was in effect at the time they were opened.)^ |
| 5464 ** |
| 5465 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled |
| 5466 ** successfully. An [error code] is returned otherwise.)^ |
| 5467 ** |
| 5468 ** ^Shared cache is disabled by default. But this might change in |
| 5469 ** future releases of SQLite. Applications that care about shared |
| 5470 ** cache setting should set it explicitly. |
| 5471 ** |
| 5472 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 |
| 5473 ** and will always return SQLITE_MISUSE. On those systems, |
| 5474 ** shared cache mode should be enabled per-database connection via |
| 5475 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. |
| 5476 ** |
| 5477 ** This interface is threadsafe on processors where writing a |
| 5478 ** 32-bit integer is atomic. |
| 5479 ** |
| 5480 ** See Also: [SQLite Shared-Cache Mode] |
| 5481 */ |
| 5482 int sqlite3_enable_shared_cache(int); |
| 5483 |
| 5484 /* |
| 5485 ** CAPI3REF: Attempt To Free Heap Memory |
| 5486 ** |
| 5487 ** ^The sqlite3_release_memory() interface attempts to free N bytes |
| 5488 ** of heap memory by deallocating non-essential memory allocations |
| 5489 ** held by the database library. Memory used to cache database |
| 5490 ** pages to improve performance is an example of non-essential memory. |
| 5491 ** ^sqlite3_release_memory() returns the number of bytes actually freed, |
| 5492 ** which might be more or less than the amount requested. |
| 5493 ** ^The sqlite3_release_memory() routine is a no-op returning zero |
| 5494 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. |
| 5495 ** |
| 5496 ** See also: [sqlite3_db_release_memory()] |
| 5497 */ |
| 5498 int sqlite3_release_memory(int); |
| 5499 |
| 5500 /* |
| 5501 ** CAPI3REF: Free Memory Used By A Database Connection |
| 5502 ** METHOD: sqlite3 |
| 5503 ** |
| 5504 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap |
| 5505 ** memory as possible from database connection D. Unlike the |
| 5506 ** [sqlite3_release_memory()] interface, this interface is in effect even |
| 5507 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is |
| 5508 ** omitted. |
| 5509 ** |
| 5510 ** See also: [sqlite3_release_memory()] |
| 5511 */ |
| 5512 int sqlite3_db_release_memory(sqlite3*); |
| 5513 |
| 5514 /* |
| 5515 ** CAPI3REF: Impose A Limit On Heap Size |
| 5516 ** |
| 5517 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the |
| 5518 ** soft limit on the amount of heap memory that may be allocated by SQLite. |
| 5519 ** ^SQLite strives to keep heap memory utilization below the soft heap |
| 5520 ** limit by reducing the number of pages held in the page cache |
| 5521 ** as heap memory usages approaches the limit. |
| 5522 ** ^The soft heap limit is "soft" because even though SQLite strives to stay |
| 5523 ** below the limit, it will exceed the limit rather than generate |
| 5524 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit |
| 5525 ** is advisory only. |
| 5526 ** |
| 5527 ** ^The return value from sqlite3_soft_heap_limit64() is the size of |
| 5528 ** the soft heap limit prior to the call, or negative in the case of an |
| 5529 ** error. ^If the argument N is negative |
| 5530 ** then no change is made to the soft heap limit. Hence, the current |
| 5531 ** size of the soft heap limit can be determined by invoking |
| 5532 ** sqlite3_soft_heap_limit64() with a negative argument. |
| 5533 ** |
| 5534 ** ^If the argument N is zero then the soft heap limit is disabled. |
| 5535 ** |
| 5536 ** ^(The soft heap limit is not enforced in the current implementation |
| 5537 ** if one or more of following conditions are true: |
| 5538 ** |
| 5539 ** <ul> |
| 5540 ** <li> The soft heap limit is set to zero. |
| 5541 ** <li> Memory accounting is disabled using a combination of the |
| 5542 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and |
| 5543 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. |
| 5544 ** <li> An alternative page cache implementation is specified using |
| 5545 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). |
| 5546 ** <li> The page cache allocates from its own memory pool supplied |
| 5547 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than |
| 5548 ** from the heap. |
| 5549 ** </ul>)^ |
| 5550 ** |
| 5551 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), |
| 5552 ** the soft heap limit is enforced |
| 5553 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] |
| 5554 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], |
| 5555 ** the soft heap limit is enforced on every memory allocation. Without |
| 5556 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced |
| 5557 ** when memory is allocated by the page cache. Testing suggests that because |
| 5558 ** the page cache is the predominate memory user in SQLite, most |
| 5559 ** applications will achieve adequate soft heap limit enforcement without |
| 5560 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. |
| 5561 ** |
| 5562 ** The circumstances under which SQLite will enforce the soft heap limit may |
| 5563 ** changes in future releases of SQLite. |
| 5564 */ |
| 5565 sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); |
| 5566 |
| 5567 /* |
| 5568 ** CAPI3REF: Deprecated Soft Heap Limit Interface |
| 5569 ** DEPRECATED |
| 5570 ** |
| 5571 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] |
| 5572 ** interface. This routine is provided for historical compatibility |
| 5573 ** only. All new applications should use the |
| 5574 ** [sqlite3_soft_heap_limit64()] interface rather than this one. |
| 5575 */ |
| 5576 SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); |
| 5577 |
| 5578 |
| 5579 /* |
| 5580 ** CAPI3REF: Extract Metadata About A Column Of A Table |
| 5581 ** METHOD: sqlite3 |
| 5582 ** |
| 5583 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns |
| 5584 ** information about column C of table T in database D |
| 5585 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() |
| 5586 ** interface returns SQLITE_OK and fills in the non-NULL pointers in |
| 5587 ** the final five arguments with appropriate values if the specified |
| 5588 ** column exists. ^The sqlite3_table_column_metadata() interface returns |
| 5589 ** SQLITE_ERROR and if the specified column does not exist. |
| 5590 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a |
| 5591 ** NULL pointer, then this routine simply checks for the existence of the |
| 5592 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it |
| 5593 ** does not. |
| 5594 ** |
| 5595 ** ^The column is identified by the second, third and fourth parameters to |
| 5596 ** this function. ^(The second parameter is either the name of the database |
| 5597 ** (i.e. "main", "temp", or an attached database) containing the specified |
| 5598 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched |
| 5599 ** for the table using the same algorithm used by the database engine to |
| 5600 ** resolve unqualified table references. |
| 5601 ** |
| 5602 ** ^The third and fourth parameters to this function are the table and column |
| 5603 ** name of the desired column, respectively. |
| 5604 ** |
| 5605 ** ^Metadata is returned by writing to the memory locations passed as the 5th |
| 5606 ** and subsequent parameters to this function. ^Any of these arguments may be |
| 5607 ** NULL, in which case the corresponding element of metadata is omitted. |
| 5608 ** |
| 5609 ** ^(<blockquote> |
| 5610 ** <table border="1"> |
| 5611 ** <tr><th> Parameter <th> Output<br>Type <th> Description |
| 5612 ** |
| 5613 ** <tr><td> 5th <td> const char* <td> Data type |
| 5614 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence |
| 5615 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint |
| 5616 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY |
| 5617 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] |
| 5618 ** </table> |
| 5619 ** </blockquote>)^ |
| 5620 ** |
| 5621 ** ^The memory pointed to by the character pointers returned for the |
| 5622 ** declaration type and collation sequence is valid until the next |
| 5623 ** call to any SQLite API function. |
| 5624 ** |
| 5625 ** ^If the specified table is actually a view, an [error code] is returned. |
| 5626 ** |
| 5627 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table |
| 5628 ** is not a [WITHOUT ROWID] table and an |
| 5629 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output |
| 5630 ** parameters are set for the explicitly declared column. ^(If there is no |
| 5631 ** [INTEGER PRIMARY KEY] column, then the outputs |
| 5632 ** for the [rowid] are set as follows: |
| 5633 ** |
| 5634 ** <pre> |
| 5635 ** data type: "INTEGER" |
| 5636 ** collation sequence: "BINARY" |
| 5637 ** not null: 0 |
| 5638 ** primary key: 1 |
| 5639 ** auto increment: 0 |
| 5640 ** </pre>)^ |
| 5641 ** |
| 5642 ** ^This function causes all database schemas to be read from disk and |
| 5643 ** parsed, if that has not already been done, and returns an error if |
| 5644 ** any errors are encountered while loading the schema. |
| 5645 */ |
| 5646 int sqlite3_table_column_metadata( |
| 5647 sqlite3 *db, /* Connection handle */ |
| 5648 const char *zDbName, /* Database name or NULL */ |
| 5649 const char *zTableName, /* Table name */ |
| 5650 const char *zColumnName, /* Column name */ |
| 5651 char const **pzDataType, /* OUTPUT: Declared data type */ |
| 5652 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ |
| 5653 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ |
| 5654 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ |
| 5655 int *pAutoinc /* OUTPUT: True if column is auto-increment */ |
| 5656 ); |
| 5657 |
| 5658 /* |
| 5659 ** CAPI3REF: Load An Extension |
| 5660 ** METHOD: sqlite3 |
| 5661 ** |
| 5662 ** ^This interface loads an SQLite extension library from the named file. |
| 5663 ** |
| 5664 ** ^The sqlite3_load_extension() interface attempts to load an |
| 5665 ** [SQLite extension] library contained in the file zFile. If |
| 5666 ** the file cannot be loaded directly, attempts are made to load |
| 5667 ** with various operating-system specific extensions added. |
| 5668 ** So for example, if "samplelib" cannot be loaded, then names like |
| 5669 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might |
| 5670 ** be tried also. |
| 5671 ** |
| 5672 ** ^The entry point is zProc. |
| 5673 ** ^(zProc may be 0, in which case SQLite will try to come up with an |
| 5674 ** entry point name on its own. It first tries "sqlite3_extension_init". |
| 5675 ** If that does not work, it constructs a name "sqlite3_X_init" where the |
| 5676 ** X is consists of the lower-case equivalent of all ASCII alphabetic |
| 5677 ** characters in the filename from the last "/" to the first following |
| 5678 ** "." and omitting any initial "lib".)^ |
| 5679 ** ^The sqlite3_load_extension() interface returns |
| 5680 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. |
| 5681 ** ^If an error occurs and pzErrMsg is not 0, then the |
| 5682 ** [sqlite3_load_extension()] interface shall attempt to |
| 5683 ** fill *pzErrMsg with error message text stored in memory |
| 5684 ** obtained from [sqlite3_malloc()]. The calling function |
| 5685 ** should free this memory by calling [sqlite3_free()]. |
| 5686 ** |
| 5687 ** ^Extension loading must be enabled using |
| 5688 ** [sqlite3_enable_load_extension()] or |
| 5689 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) |
| 5690 ** prior to calling this API, |
| 5691 ** otherwise an error will be returned. |
| 5692 ** |
| 5693 ** <b>Security warning:</b> It is recommended that the |
| 5694 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this |
| 5695 ** interface. The use of the [sqlite3_enable_load_extension()] interface |
| 5696 ** should be avoided. This will keep the SQL function [load_extension()] |
| 5697 ** disabled and prevent SQL injections from giving attackers |
| 5698 ** access to extension loading capabilities. |
| 5699 ** |
| 5700 ** See also the [load_extension() SQL function]. |
| 5701 */ |
| 5702 int sqlite3_load_extension( |
| 5703 sqlite3 *db, /* Load the extension into this database connection */ |
| 5704 const char *zFile, /* Name of the shared library containing extension */ |
| 5705 const char *zProc, /* Entry point. Derived from zFile if 0 */ |
| 5706 char **pzErrMsg /* Put error message here if not 0 */ |
| 5707 ); |
| 5708 |
| 5709 /* |
| 5710 ** CAPI3REF: Enable Or Disable Extension Loading |
| 5711 ** METHOD: sqlite3 |
| 5712 ** |
| 5713 ** ^So as not to open security holes in older applications that are |
| 5714 ** unprepared to deal with [extension loading], and as a means of disabling |
| 5715 ** [extension loading] while evaluating user-entered SQL, the following API |
| 5716 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. |
| 5717 ** |
| 5718 ** ^Extension loading is off by default. |
| 5719 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 |
| 5720 ** to turn extension loading on and call it with onoff==0 to turn |
| 5721 ** it back off again. |
| 5722 ** |
| 5723 ** ^This interface enables or disables both the C-API |
| 5724 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. |
| 5725 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) |
| 5726 ** to enable or disable only the C-API.)^ |
| 5727 ** |
| 5728 ** <b>Security warning:</b> It is recommended that extension loading |
| 5729 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method |
| 5730 ** rather than this interface, so the [load_extension()] SQL function |
| 5731 ** remains disabled. This will prevent SQL injections from giving attackers |
| 5732 ** access to extension loading capabilities. |
| 5733 */ |
| 5734 int sqlite3_enable_load_extension(sqlite3 *db, int onoff); |
| 5735 |
| 5736 /* |
| 5737 ** CAPI3REF: Automatically Load Statically Linked Extensions |
| 5738 ** |
| 5739 ** ^This interface causes the xEntryPoint() function to be invoked for |
| 5740 ** each new [database connection] that is created. The idea here is that |
| 5741 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] |
| 5742 ** that is to be automatically loaded into all new database connections. |
| 5743 ** |
| 5744 ** ^(Even though the function prototype shows that xEntryPoint() takes |
| 5745 ** no arguments and returns void, SQLite invokes xEntryPoint() with three |
| 5746 ** arguments and expects an integer result as if the signature of the |
| 5747 ** entry point where as follows: |
| 5748 ** |
| 5749 ** <blockquote><pre> |
| 5750 ** int xEntryPoint( |
| 5751 ** sqlite3 *db, |
| 5752 ** const char **pzErrMsg, |
| 5753 ** const struct sqlite3_api_routines *pThunk |
| 5754 ** ); |
| 5755 ** </pre></blockquote>)^ |
| 5756 ** |
| 5757 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg |
| 5758 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) |
| 5759 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg |
| 5760 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke |
| 5761 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any |
| 5762 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], |
| 5763 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. |
| 5764 ** |
| 5765 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already |
| 5766 ** on the list of automatic extensions is a harmless no-op. ^No entry point |
| 5767 ** will be called more than once for each database connection that is opened. |
| 5768 ** |
| 5769 ** See also: [sqlite3_reset_auto_extension()] |
| 5770 ** and [sqlite3_cancel_auto_extension()] |
| 5771 */ |
| 5772 int sqlite3_auto_extension(void(*xEntryPoint)(void)); |
| 5773 |
| 5774 /* |
| 5775 ** CAPI3REF: Cancel Automatic Extension Loading |
| 5776 ** |
| 5777 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the |
| 5778 ** initialization routine X that was registered using a prior call to |
| 5779 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] |
| 5780 ** routine returns 1 if initialization routine X was successfully |
| 5781 ** unregistered and it returns 0 if X was not on the list of initialization |
| 5782 ** routines. |
| 5783 */ |
| 5784 int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); |
| 5785 |
| 5786 /* |
| 5787 ** CAPI3REF: Reset Automatic Extension Loading |
| 5788 ** |
| 5789 ** ^This interface disables all automatic extensions previously |
| 5790 ** registered using [sqlite3_auto_extension()]. |
| 5791 */ |
| 5792 void sqlite3_reset_auto_extension(void); |
| 5793 |
| 5794 /* |
| 5795 ** The interface to the virtual-table mechanism is currently considered |
| 5796 ** to be experimental. The interface might change in incompatible ways. |
| 5797 ** If this is a problem for you, do not use the interface at this time. |
| 5798 ** |
| 5799 ** When the virtual-table mechanism stabilizes, we will declare the |
| 5800 ** interface fixed, support it indefinitely, and remove this comment. |
| 5801 */ |
| 5802 |
| 5803 /* |
| 5804 ** Structures used by the virtual table interface |
| 5805 */ |
| 5806 typedef struct sqlite3_vtab sqlite3_vtab; |
| 5807 typedef struct sqlite3_index_info sqlite3_index_info; |
| 5808 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; |
| 5809 typedef struct sqlite3_module sqlite3_module; |
| 5810 |
| 5811 /* |
| 5812 ** CAPI3REF: Virtual Table Object |
| 5813 ** KEYWORDS: sqlite3_module {virtual table module} |
| 5814 ** |
| 5815 ** This structure, sometimes called a "virtual table module", |
| 5816 ** defines the implementation of a [virtual tables]. |
| 5817 ** This structure consists mostly of methods for the module. |
| 5818 ** |
| 5819 ** ^A virtual table module is created by filling in a persistent |
| 5820 ** instance of this structure and passing a pointer to that instance |
| 5821 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. |
| 5822 ** ^The registration remains valid until it is replaced by a different |
| 5823 ** module or until the [database connection] closes. The content |
| 5824 ** of this structure must not change while it is registered with |
| 5825 ** any database connection. |
| 5826 */ |
| 5827 struct sqlite3_module { |
| 5828 int iVersion; |
| 5829 int (*xCreate)(sqlite3*, void *pAux, |
| 5830 int argc, const char *const*argv, |
| 5831 sqlite3_vtab **ppVTab, char**); |
| 5832 int (*xConnect)(sqlite3*, void *pAux, |
| 5833 int argc, const char *const*argv, |
| 5834 sqlite3_vtab **ppVTab, char**); |
| 5835 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); |
| 5836 int (*xDisconnect)(sqlite3_vtab *pVTab); |
| 5837 int (*xDestroy)(sqlite3_vtab *pVTab); |
| 5838 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); |
| 5839 int (*xClose)(sqlite3_vtab_cursor*); |
| 5840 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, |
| 5841 int argc, sqlite3_value **argv); |
| 5842 int (*xNext)(sqlite3_vtab_cursor*); |
| 5843 int (*xEof)(sqlite3_vtab_cursor*); |
| 5844 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); |
| 5845 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); |
| 5846 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); |
| 5847 int (*xBegin)(sqlite3_vtab *pVTab); |
| 5848 int (*xSync)(sqlite3_vtab *pVTab); |
| 5849 int (*xCommit)(sqlite3_vtab *pVTab); |
| 5850 int (*xRollback)(sqlite3_vtab *pVTab); |
| 5851 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, |
| 5852 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), |
| 5853 void **ppArg); |
| 5854 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); |
| 5855 /* The methods above are in version 1 of the sqlite_module object. Those |
| 5856 ** below are for version 2 and greater. */ |
| 5857 int (*xSavepoint)(sqlite3_vtab *pVTab, int); |
| 5858 int (*xRelease)(sqlite3_vtab *pVTab, int); |
| 5859 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); |
| 5860 }; |
| 5861 |
| 5862 /* |
| 5863 ** CAPI3REF: Virtual Table Indexing Information |
| 5864 ** KEYWORDS: sqlite3_index_info |
| 5865 ** |
| 5866 ** The sqlite3_index_info structure and its substructures is used as part |
| 5867 ** of the [virtual table] interface to |
| 5868 ** pass information into and receive the reply from the [xBestIndex] |
| 5869 ** method of a [virtual table module]. The fields under **Inputs** are the |
| 5870 ** inputs to xBestIndex and are read-only. xBestIndex inserts its |
| 5871 ** results into the **Outputs** fields. |
| 5872 ** |
| 5873 ** ^(The aConstraint[] array records WHERE clause constraints of the form: |
| 5874 ** |
| 5875 ** <blockquote>column OP expr</blockquote> |
| 5876 ** |
| 5877 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is |
| 5878 ** stored in aConstraint[].op using one of the |
| 5879 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ |
| 5880 ** ^(The index of the column is stored in |
| 5881 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the |
| 5882 ** expr on the right-hand side can be evaluated (and thus the constraint |
| 5883 ** is usable) and false if it cannot.)^ |
| 5884 ** |
| 5885 ** ^The optimizer automatically inverts terms of the form "expr OP column" |
| 5886 ** and makes other simplifications to the WHERE clause in an attempt to |
| 5887 ** get as many WHERE clause terms into the form shown above as possible. |
| 5888 ** ^The aConstraint[] array only reports WHERE clause terms that are |
| 5889 ** relevant to the particular virtual table being queried. |
| 5890 ** |
| 5891 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. |
| 5892 ** ^Each term of aOrderBy records a column of the ORDER BY clause. |
| 5893 ** |
| 5894 ** The colUsed field indicates which columns of the virtual table may be |
| 5895 ** required by the current scan. Virtual table columns are numbered from |
| 5896 ** zero in the order in which they appear within the CREATE TABLE statement |
| 5897 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), |
| 5898 ** the corresponding bit is set within the colUsed mask if the column may be |
| 5899 ** required by SQLite. If the table has at least 64 columns and any column |
| 5900 ** to the right of the first 63 is required, then bit 63 of colUsed is also |
| 5901 ** set. In other words, column iCol may be required if the expression |
| 5902 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to |
| 5903 ** non-zero. |
| 5904 ** |
| 5905 ** The [xBestIndex] method must fill aConstraintUsage[] with information |
| 5906 ** about what parameters to pass to xFilter. ^If argvIndex>0 then |
| 5907 ** the right-hand side of the corresponding aConstraint[] is evaluated |
| 5908 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit |
| 5909 ** is true, then the constraint is assumed to be fully handled by the |
| 5910 ** virtual table and is not checked again by SQLite.)^ |
| 5911 ** |
| 5912 ** ^The idxNum and idxPtr values are recorded and passed into the |
| 5913 ** [xFilter] method. |
| 5914 ** ^[sqlite3_free()] is used to free idxPtr if and only if |
| 5915 ** needToFreeIdxPtr is true. |
| 5916 ** |
| 5917 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in |
| 5918 ** the correct order to satisfy the ORDER BY clause so that no separate |
| 5919 ** sorting step is required. |
| 5920 ** |
| 5921 ** ^The estimatedCost value is an estimate of the cost of a particular |
| 5922 ** strategy. A cost of N indicates that the cost of the strategy is similar |
| 5923 ** to a linear scan of an SQLite table with N rows. A cost of log(N) |
| 5924 ** indicates that the expense of the operation is similar to that of a |
| 5925 ** binary search on a unique indexed field of an SQLite table with N rows. |
| 5926 ** |
| 5927 ** ^The estimatedRows value is an estimate of the number of rows that |
| 5928 ** will be returned by the strategy. |
| 5929 ** |
| 5930 ** The xBestIndex method may optionally populate the idxFlags field with a |
| 5931 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - |
| 5932 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite |
| 5933 ** assumes that the strategy may visit at most one row. |
| 5934 ** |
| 5935 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then |
| 5936 ** SQLite also assumes that if a call to the xUpdate() method is made as |
| 5937 ** part of the same statement to delete or update a virtual table row and the |
| 5938 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback |
| 5939 ** any database changes. In other words, if the xUpdate() returns |
| 5940 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were |
| 5941 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not |
| 5942 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by |
| 5943 ** the xUpdate method are automatically rolled back by SQLite. |
| 5944 ** |
| 5945 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info |
| 5946 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). |
| 5947 ** If a virtual table extension is |
| 5948 ** used with an SQLite version earlier than 3.8.2, the results of attempting |
| 5949 ** to read or write the estimatedRows field are undefined (but are likely |
| 5950 ** to included crashing the application). The estimatedRows field should |
| 5951 ** therefore only be used if [sqlite3_libversion_number()] returns a |
| 5952 ** value greater than or equal to 3008002. Similarly, the idxFlags field |
| 5953 ** was added for [version 3.9.0] ([dateof:3.9.0]). |
| 5954 ** It may therefore only be used if |
| 5955 ** sqlite3_libversion_number() returns a value greater than or equal to |
| 5956 ** 3009000. |
| 5957 */ |
| 5958 struct sqlite3_index_info { |
| 5959 /* Inputs */ |
| 5960 int nConstraint; /* Number of entries in aConstraint */ |
| 5961 struct sqlite3_index_constraint { |
| 5962 int iColumn; /* Column constrained. -1 for ROWID */ |
| 5963 unsigned char op; /* Constraint operator */ |
| 5964 unsigned char usable; /* True if this constraint is usable */ |
| 5965 int iTermOffset; /* Used internally - xBestIndex should ignore */ |
| 5966 } *aConstraint; /* Table of WHERE clause constraints */ |
| 5967 int nOrderBy; /* Number of terms in the ORDER BY clause */ |
| 5968 struct sqlite3_index_orderby { |
| 5969 int iColumn; /* Column number */ |
| 5970 unsigned char desc; /* True for DESC. False for ASC. */ |
| 5971 } *aOrderBy; /* The ORDER BY clause */ |
| 5972 /* Outputs */ |
| 5973 struct sqlite3_index_constraint_usage { |
| 5974 int argvIndex; /* if >0, constraint is part of argv to xFilter */ |
| 5975 unsigned char omit; /* Do not code a test for this constraint */ |
| 5976 } *aConstraintUsage; |
| 5977 int idxNum; /* Number used to identify the index */ |
| 5978 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ |
| 5979 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ |
| 5980 int orderByConsumed; /* True if output is already ordered */ |
| 5981 double estimatedCost; /* Estimated cost of using this index */ |
| 5982 /* Fields below are only available in SQLite 3.8.2 and later */ |
| 5983 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ |
| 5984 /* Fields below are only available in SQLite 3.9.0 and later */ |
| 5985 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ |
| 5986 /* Fields below are only available in SQLite 3.10.0 and later */ |
| 5987 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ |
| 5988 }; |
| 5989 |
| 5990 /* |
| 5991 ** CAPI3REF: Virtual Table Scan Flags |
| 5992 */ |
| 5993 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ |
| 5994 |
| 5995 /* |
| 5996 ** CAPI3REF: Virtual Table Constraint Operator Codes |
| 5997 ** |
| 5998 ** These macros defined the allowed values for the |
| 5999 ** [sqlite3_index_info].aConstraint[].op field. Each value represents |
| 6000 ** an operator that is part of a constraint term in the wHERE clause of |
| 6001 ** a query that uses a [virtual table]. |
| 6002 */ |
| 6003 #define SQLITE_INDEX_CONSTRAINT_EQ 2 |
| 6004 #define SQLITE_INDEX_CONSTRAINT_GT 4 |
| 6005 #define SQLITE_INDEX_CONSTRAINT_LE 8 |
| 6006 #define SQLITE_INDEX_CONSTRAINT_LT 16 |
| 6007 #define SQLITE_INDEX_CONSTRAINT_GE 32 |
| 6008 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 |
| 6009 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 |
| 6010 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 |
| 6011 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 |
| 6012 |
| 6013 /* |
| 6014 ** CAPI3REF: Register A Virtual Table Implementation |
| 6015 ** METHOD: sqlite3 |
| 6016 ** |
| 6017 ** ^These routines are used to register a new [virtual table module] name. |
| 6018 ** ^Module names must be registered before |
| 6019 ** creating a new [virtual table] using the module and before using a |
| 6020 ** preexisting [virtual table] for the module. |
| 6021 ** |
| 6022 ** ^The module name is registered on the [database connection] specified |
| 6023 ** by the first parameter. ^The name of the module is given by the |
| 6024 ** second parameter. ^The third parameter is a pointer to |
| 6025 ** the implementation of the [virtual table module]. ^The fourth |
| 6026 ** parameter is an arbitrary client data pointer that is passed through |
| 6027 ** into the [xCreate] and [xConnect] methods of the virtual table module |
| 6028 ** when a new virtual table is be being created or reinitialized. |
| 6029 ** |
| 6030 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which |
| 6031 ** is a pointer to a destructor for the pClientData. ^SQLite will |
| 6032 ** invoke the destructor function (if it is not NULL) when SQLite |
| 6033 ** no longer needs the pClientData pointer. ^The destructor will also |
| 6034 ** be invoked if the call to sqlite3_create_module_v2() fails. |
| 6035 ** ^The sqlite3_create_module() |
| 6036 ** interface is equivalent to sqlite3_create_module_v2() with a NULL |
| 6037 ** destructor. |
| 6038 */ |
| 6039 int sqlite3_create_module( |
| 6040 sqlite3 *db, /* SQLite connection to register module with */ |
| 6041 const char *zName, /* Name of the module */ |
| 6042 const sqlite3_module *p, /* Methods for the module */ |
| 6043 void *pClientData /* Client data for xCreate/xConnect */ |
| 6044 ); |
| 6045 int sqlite3_create_module_v2( |
| 6046 sqlite3 *db, /* SQLite connection to register module with */ |
| 6047 const char *zName, /* Name of the module */ |
| 6048 const sqlite3_module *p, /* Methods for the module */ |
| 6049 void *pClientData, /* Client data for xCreate/xConnect */ |
| 6050 void(*xDestroy)(void*) /* Module destructor function */ |
| 6051 ); |
| 6052 |
| 6053 /* |
| 6054 ** CAPI3REF: Virtual Table Instance Object |
| 6055 ** KEYWORDS: sqlite3_vtab |
| 6056 ** |
| 6057 ** Every [virtual table module] implementation uses a subclass |
| 6058 ** of this object to describe a particular instance |
| 6059 ** of the [virtual table]. Each subclass will |
| 6060 ** be tailored to the specific needs of the module implementation. |
| 6061 ** The purpose of this superclass is to define certain fields that are |
| 6062 ** common to all module implementations. |
| 6063 ** |
| 6064 ** ^Virtual tables methods can set an error message by assigning a |
| 6065 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should |
| 6066 ** take care that any prior string is freed by a call to [sqlite3_free()] |
| 6067 ** prior to assigning a new string to zErrMsg. ^After the error message |
| 6068 ** is delivered up to the client application, the string will be automatically |
| 6069 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. |
| 6070 */ |
| 6071 struct sqlite3_vtab { |
| 6072 const sqlite3_module *pModule; /* The module for this virtual table */ |
| 6073 int nRef; /* Number of open cursors */ |
| 6074 char *zErrMsg; /* Error message from sqlite3_mprintf() */ |
| 6075 /* Virtual table implementations will typically add additional fields */ |
| 6076 }; |
| 6077 |
| 6078 /* |
| 6079 ** CAPI3REF: Virtual Table Cursor Object |
| 6080 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} |
| 6081 ** |
| 6082 ** Every [virtual table module] implementation uses a subclass of the |
| 6083 ** following structure to describe cursors that point into the |
| 6084 ** [virtual table] and are used |
| 6085 ** to loop through the virtual table. Cursors are created using the |
| 6086 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed |
| 6087 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used |
| 6088 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods |
| 6089 ** of the module. Each module implementation will define |
| 6090 ** the content of a cursor structure to suit its own needs. |
| 6091 ** |
| 6092 ** This superclass exists in order to define fields of the cursor that |
| 6093 ** are common to all implementations. |
| 6094 */ |
| 6095 struct sqlite3_vtab_cursor { |
| 6096 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ |
| 6097 /* Virtual table implementations will typically add additional fields */ |
| 6098 }; |
| 6099 |
| 6100 /* |
| 6101 ** CAPI3REF: Declare The Schema Of A Virtual Table |
| 6102 ** |
| 6103 ** ^The [xCreate] and [xConnect] methods of a |
| 6104 ** [virtual table module] call this interface |
| 6105 ** to declare the format (the names and datatypes of the columns) of |
| 6106 ** the virtual tables they implement. |
| 6107 */ |
| 6108 int sqlite3_declare_vtab(sqlite3*, const char *zSQL); |
| 6109 |
| 6110 /* |
| 6111 ** CAPI3REF: Overload A Function For A Virtual Table |
| 6112 ** METHOD: sqlite3 |
| 6113 ** |
| 6114 ** ^(Virtual tables can provide alternative implementations of functions |
| 6115 ** using the [xFindFunction] method of the [virtual table module]. |
| 6116 ** But global versions of those functions |
| 6117 ** must exist in order to be overloaded.)^ |
| 6118 ** |
| 6119 ** ^(This API makes sure a global version of a function with a particular |
| 6120 ** name and number of parameters exists. If no such function exists |
| 6121 ** before this API is called, a new function is created.)^ ^The implementation |
| 6122 ** of the new function always causes an exception to be thrown. So |
| 6123 ** the new function is not good for anything by itself. Its only |
| 6124 ** purpose is to be a placeholder function that can be overloaded |
| 6125 ** by a [virtual table]. |
| 6126 */ |
| 6127 int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); |
| 6128 |
| 6129 /* |
| 6130 ** The interface to the virtual-table mechanism defined above (back up |
| 6131 ** to a comment remarkably similar to this one) is currently considered |
| 6132 ** to be experimental. The interface might change in incompatible ways. |
| 6133 ** If this is a problem for you, do not use the interface at this time. |
| 6134 ** |
| 6135 ** When the virtual-table mechanism stabilizes, we will declare the |
| 6136 ** interface fixed, support it indefinitely, and remove this comment. |
| 6137 */ |
| 6138 |
| 6139 /* |
| 6140 ** CAPI3REF: A Handle To An Open BLOB |
| 6141 ** KEYWORDS: {BLOB handle} {BLOB handles} |
| 6142 ** |
| 6143 ** An instance of this object represents an open BLOB on which |
| 6144 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. |
| 6145 ** ^Objects of this type are created by [sqlite3_blob_open()] |
| 6146 ** and destroyed by [sqlite3_blob_close()]. |
| 6147 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces |
| 6148 ** can be used to read or write small subsections of the BLOB. |
| 6149 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. |
| 6150 */ |
| 6151 typedef struct sqlite3_blob sqlite3_blob; |
| 6152 |
| 6153 /* |
| 6154 ** CAPI3REF: Open A BLOB For Incremental I/O |
| 6155 ** METHOD: sqlite3 |
| 6156 ** CONSTRUCTOR: sqlite3_blob |
| 6157 ** |
| 6158 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located |
| 6159 ** in row iRow, column zColumn, table zTable in database zDb; |
| 6160 ** in other words, the same BLOB that would be selected by: |
| 6161 ** |
| 6162 ** <pre> |
| 6163 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; |
| 6164 ** </pre>)^ |
| 6165 ** |
| 6166 ** ^(Parameter zDb is not the filename that contains the database, but |
| 6167 ** rather the symbolic name of the database. For attached databases, this is |
| 6168 ** the name that appears after the AS keyword in the [ATTACH] statement. |
| 6169 ** For the main database file, the database name is "main". For TEMP |
| 6170 ** tables, the database name is "temp".)^ |
| 6171 ** |
| 6172 ** ^If the flags parameter is non-zero, then the BLOB is opened for read |
| 6173 ** and write access. ^If the flags parameter is zero, the BLOB is opened for |
| 6174 ** read-only access. |
| 6175 ** |
| 6176 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored |
| 6177 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error |
| 6178 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided |
| 6179 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] |
| 6180 ** on *ppBlob after this function it returns. |
| 6181 ** |
| 6182 ** This function fails with SQLITE_ERROR if any of the following are true: |
| 6183 ** <ul> |
| 6184 ** <li> ^(Database zDb does not exist)^, |
| 6185 ** <li> ^(Table zTable does not exist within database zDb)^, |
| 6186 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, |
| 6187 ** <li> ^(Column zColumn does not exist)^, |
| 6188 ** <li> ^(Row iRow is not present in the table)^, |
| 6189 ** <li> ^(The specified column of row iRow contains a value that is not |
| 6190 ** a TEXT or BLOB value)^, |
| 6191 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE |
| 6192 ** constraint and the blob is being opened for read/write access)^, |
| 6193 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, |
| 6194 ** column zColumn is part of a [child key] definition and the blob is |
| 6195 ** being opened for read/write access)^. |
| 6196 ** </ul> |
| 6197 ** |
| 6198 ** ^Unless it returns SQLITE_MISUSE, this function sets the |
| 6199 ** [database connection] error code and message accessible via |
| 6200 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. |
| 6201 ** |
| 6202 ** A BLOB referenced by sqlite3_blob_open() may be read using the |
| 6203 ** [sqlite3_blob_read()] interface and modified by using |
| 6204 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a |
| 6205 ** different row of the same table using the [sqlite3_blob_reopen()] |
| 6206 ** interface. However, the column, table, or database of a [BLOB handle] |
| 6207 ** cannot be changed after the [BLOB handle] is opened. |
| 6208 ** |
| 6209 ** ^(If the row that a BLOB handle points to is modified by an |
| 6210 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects |
| 6211 ** then the BLOB handle is marked as "expired". |
| 6212 ** This is true if any column of the row is changed, even a column |
| 6213 ** other than the one the BLOB handle is open on.)^ |
| 6214 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for |
| 6215 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. |
| 6216 ** ^(Changes written into a BLOB prior to the BLOB expiring are not |
| 6217 ** rolled back by the expiration of the BLOB. Such changes will eventually |
| 6218 ** commit if the transaction continues to completion.)^ |
| 6219 ** |
| 6220 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of |
| 6221 ** the opened blob. ^The size of a blob may not be changed by this |
| 6222 ** interface. Use the [UPDATE] SQL command to change the size of a |
| 6223 ** blob. |
| 6224 ** |
| 6225 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces |
| 6226 ** and the built-in [zeroblob] SQL function may be used to create a |
| 6227 ** zero-filled blob to read or write using the incremental-blob interface. |
| 6228 ** |
| 6229 ** To avoid a resource leak, every open [BLOB handle] should eventually |
| 6230 ** be released by a call to [sqlite3_blob_close()]. |
| 6231 ** |
| 6232 ** See also: [sqlite3_blob_close()], |
| 6233 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], |
| 6234 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. |
| 6235 */ |
| 6236 int sqlite3_blob_open( |
| 6237 sqlite3*, |
| 6238 const char *zDb, |
| 6239 const char *zTable, |
| 6240 const char *zColumn, |
| 6241 sqlite3_int64 iRow, |
| 6242 int flags, |
| 6243 sqlite3_blob **ppBlob |
| 6244 ); |
| 6245 |
| 6246 /* |
| 6247 ** CAPI3REF: Move a BLOB Handle to a New Row |
| 6248 ** METHOD: sqlite3_blob |
| 6249 ** |
| 6250 ** ^This function is used to move an existing [BLOB handle] so that it points |
| 6251 ** to a different row of the same database table. ^The new row is identified |
| 6252 ** by the rowid value passed as the second argument. Only the row can be |
| 6253 ** changed. ^The database, table and column on which the blob handle is open |
| 6254 ** remain the same. Moving an existing [BLOB handle] to a new row is |
| 6255 ** faster than closing the existing handle and opening a new one. |
| 6256 ** |
| 6257 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - |
| 6258 ** it must exist and there must be either a blob or text value stored in |
| 6259 ** the nominated column.)^ ^If the new row is not present in the table, or if |
| 6260 ** it does not contain a blob or text value, or if another error occurs, an |
| 6261 ** SQLite error code is returned and the blob handle is considered aborted. |
| 6262 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or |
| 6263 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return |
| 6264 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle |
| 6265 ** always returns zero. |
| 6266 ** |
| 6267 ** ^This function sets the database handle error code and message. |
| 6268 */ |
| 6269 int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); |
| 6270 |
| 6271 /* |
| 6272 ** CAPI3REF: Close A BLOB Handle |
| 6273 ** DESTRUCTOR: sqlite3_blob |
| 6274 ** |
| 6275 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed |
| 6276 ** unconditionally. Even if this routine returns an error code, the |
| 6277 ** handle is still closed.)^ |
| 6278 ** |
| 6279 ** ^If the blob handle being closed was opened for read-write access, and if |
| 6280 ** the database is in auto-commit mode and there are no other open read-write |
| 6281 ** blob handles or active write statements, the current transaction is |
| 6282 ** committed. ^If an error occurs while committing the transaction, an error |
| 6283 ** code is returned and the transaction rolled back. |
| 6284 ** |
| 6285 ** Calling this function with an argument that is not a NULL pointer or an |
| 6286 ** open blob handle results in undefined behaviour. ^Calling this routine |
| 6287 ** with a null pointer (such as would be returned by a failed call to |
| 6288 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function |
| 6289 ** is passed a valid open blob handle, the values returned by the |
| 6290 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. |
| 6291 */ |
| 6292 int sqlite3_blob_close(sqlite3_blob *); |
| 6293 |
| 6294 /* |
| 6295 ** CAPI3REF: Return The Size Of An Open BLOB |
| 6296 ** METHOD: sqlite3_blob |
| 6297 ** |
| 6298 ** ^Returns the size in bytes of the BLOB accessible via the |
| 6299 ** successfully opened [BLOB handle] in its only argument. ^The |
| 6300 ** incremental blob I/O routines can only read or overwriting existing |
| 6301 ** blob content; they cannot change the size of a blob. |
| 6302 ** |
| 6303 ** This routine only works on a [BLOB handle] which has been created |
| 6304 ** by a prior successful call to [sqlite3_blob_open()] and which has not |
| 6305 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in |
| 6306 ** to this routine results in undefined and probably undesirable behavior. |
| 6307 */ |
| 6308 int sqlite3_blob_bytes(sqlite3_blob *); |
| 6309 |
| 6310 /* |
| 6311 ** CAPI3REF: Read Data From A BLOB Incrementally |
| 6312 ** METHOD: sqlite3_blob |
| 6313 ** |
| 6314 ** ^(This function is used to read data from an open [BLOB handle] into a |
| 6315 ** caller-supplied buffer. N bytes of data are copied into buffer Z |
| 6316 ** from the open BLOB, starting at offset iOffset.)^ |
| 6317 ** |
| 6318 ** ^If offset iOffset is less than N bytes from the end of the BLOB, |
| 6319 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is |
| 6320 ** less than zero, [SQLITE_ERROR] is returned and no data is read. |
| 6321 ** ^The size of the blob (and hence the maximum value of N+iOffset) |
| 6322 ** can be determined using the [sqlite3_blob_bytes()] interface. |
| 6323 ** |
| 6324 ** ^An attempt to read from an expired [BLOB handle] fails with an |
| 6325 ** error code of [SQLITE_ABORT]. |
| 6326 ** |
| 6327 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. |
| 6328 ** Otherwise, an [error code] or an [extended error code] is returned.)^ |
| 6329 ** |
| 6330 ** This routine only works on a [BLOB handle] which has been created |
| 6331 ** by a prior successful call to [sqlite3_blob_open()] and which has not |
| 6332 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in |
| 6333 ** to this routine results in undefined and probably undesirable behavior. |
| 6334 ** |
| 6335 ** See also: [sqlite3_blob_write()]. |
| 6336 */ |
| 6337 int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); |
| 6338 |
| 6339 /* |
| 6340 ** CAPI3REF: Write Data Into A BLOB Incrementally |
| 6341 ** METHOD: sqlite3_blob |
| 6342 ** |
| 6343 ** ^(This function is used to write data into an open [BLOB handle] from a |
| 6344 ** caller-supplied buffer. N bytes of data are copied from the buffer Z |
| 6345 ** into the open BLOB, starting at offset iOffset.)^ |
| 6346 ** |
| 6347 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. |
| 6348 ** Otherwise, an [error code] or an [extended error code] is returned.)^ |
| 6349 ** ^Unless SQLITE_MISUSE is returned, this function sets the |
| 6350 ** [database connection] error code and message accessible via |
| 6351 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. |
| 6352 ** |
| 6353 ** ^If the [BLOB handle] passed as the first argument was not opened for |
| 6354 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), |
| 6355 ** this function returns [SQLITE_READONLY]. |
| 6356 ** |
| 6357 ** This function may only modify the contents of the BLOB; it is |
| 6358 ** not possible to increase the size of a BLOB using this API. |
| 6359 ** ^If offset iOffset is less than N bytes from the end of the BLOB, |
| 6360 ** [SQLITE_ERROR] is returned and no data is written. The size of the |
| 6361 ** BLOB (and hence the maximum value of N+iOffset) can be determined |
| 6362 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less |
| 6363 ** than zero [SQLITE_ERROR] is returned and no data is written. |
| 6364 ** |
| 6365 ** ^An attempt to write to an expired [BLOB handle] fails with an |
| 6366 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred |
| 6367 ** before the [BLOB handle] expired are not rolled back by the |
| 6368 ** expiration of the handle, though of course those changes might |
| 6369 ** have been overwritten by the statement that expired the BLOB handle |
| 6370 ** or by other independent statements. |
| 6371 ** |
| 6372 ** This routine only works on a [BLOB handle] which has been created |
| 6373 ** by a prior successful call to [sqlite3_blob_open()] and which has not |
| 6374 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in |
| 6375 ** to this routine results in undefined and probably undesirable behavior. |
| 6376 ** |
| 6377 ** See also: [sqlite3_blob_read()]. |
| 6378 */ |
| 6379 int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); |
| 6380 |
| 6381 /* |
| 6382 ** CAPI3REF: Virtual File System Objects |
| 6383 ** |
| 6384 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object |
| 6385 ** that SQLite uses to interact |
| 6386 ** with the underlying operating system. Most SQLite builds come with a |
| 6387 ** single default VFS that is appropriate for the host computer. |
| 6388 ** New VFSes can be registered and existing VFSes can be unregistered. |
| 6389 ** The following interfaces are provided. |
| 6390 ** |
| 6391 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. |
| 6392 ** ^Names are case sensitive. |
| 6393 ** ^Names are zero-terminated UTF-8 strings. |
| 6394 ** ^If there is no match, a NULL pointer is returned. |
| 6395 ** ^If zVfsName is NULL then the default VFS is returned. |
| 6396 ** |
| 6397 ** ^New VFSes are registered with sqlite3_vfs_register(). |
| 6398 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. |
| 6399 ** ^The same VFS can be registered multiple times without injury. |
| 6400 ** ^To make an existing VFS into the default VFS, register it again |
| 6401 ** with the makeDflt flag set. If two different VFSes with the |
| 6402 ** same name are registered, the behavior is undefined. If a |
| 6403 ** VFS is registered with a name that is NULL or an empty string, |
| 6404 ** then the behavior is undefined. |
| 6405 ** |
| 6406 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. |
| 6407 ** ^(If the default VFS is unregistered, another VFS is chosen as |
| 6408 ** the default. The choice for the new VFS is arbitrary.)^ |
| 6409 */ |
| 6410 sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); |
| 6411 int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); |
| 6412 int sqlite3_vfs_unregister(sqlite3_vfs*); |
| 6413 |
| 6414 /* |
| 6415 ** CAPI3REF: Mutexes |
| 6416 ** |
| 6417 ** The SQLite core uses these routines for thread |
| 6418 ** synchronization. Though they are intended for internal |
| 6419 ** use by SQLite, code that links against SQLite is |
| 6420 ** permitted to use any of these routines. |
| 6421 ** |
| 6422 ** The SQLite source code contains multiple implementations |
| 6423 ** of these mutex routines. An appropriate implementation |
| 6424 ** is selected automatically at compile-time. The following |
| 6425 ** implementations are available in the SQLite core: |
| 6426 ** |
| 6427 ** <ul> |
| 6428 ** <li> SQLITE_MUTEX_PTHREADS |
| 6429 ** <li> SQLITE_MUTEX_W32 |
| 6430 ** <li> SQLITE_MUTEX_NOOP |
| 6431 ** </ul> |
| 6432 ** |
| 6433 ** The SQLITE_MUTEX_NOOP implementation is a set of routines |
| 6434 ** that does no real locking and is appropriate for use in |
| 6435 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and |
| 6436 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix |
| 6437 ** and Windows. |
| 6438 ** |
| 6439 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor |
| 6440 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex |
| 6441 ** implementation is included with the library. In this case the |
| 6442 ** application must supply a custom mutex implementation using the |
| 6443 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function |
| 6444 ** before calling sqlite3_initialize() or any other public sqlite3_ |
| 6445 ** function that calls sqlite3_initialize(). |
| 6446 ** |
| 6447 ** ^The sqlite3_mutex_alloc() routine allocates a new |
| 6448 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() |
| 6449 ** routine returns NULL if it is unable to allocate the requested |
| 6450 ** mutex. The argument to sqlite3_mutex_alloc() must one of these |
| 6451 ** integer constants: |
| 6452 ** |
| 6453 ** <ul> |
| 6454 ** <li> SQLITE_MUTEX_FAST |
| 6455 ** <li> SQLITE_MUTEX_RECURSIVE |
| 6456 ** <li> SQLITE_MUTEX_STATIC_MASTER |
| 6457 ** <li> SQLITE_MUTEX_STATIC_MEM |
| 6458 ** <li> SQLITE_MUTEX_STATIC_OPEN |
| 6459 ** <li> SQLITE_MUTEX_STATIC_PRNG |
| 6460 ** <li> SQLITE_MUTEX_STATIC_LRU |
| 6461 ** <li> SQLITE_MUTEX_STATIC_PMEM |
| 6462 ** <li> SQLITE_MUTEX_STATIC_APP1 |
| 6463 ** <li> SQLITE_MUTEX_STATIC_APP2 |
| 6464 ** <li> SQLITE_MUTEX_STATIC_APP3 |
| 6465 ** <li> SQLITE_MUTEX_STATIC_VFS1 |
| 6466 ** <li> SQLITE_MUTEX_STATIC_VFS2 |
| 6467 ** <li> SQLITE_MUTEX_STATIC_VFS3 |
| 6468 ** </ul> |
| 6469 ** |
| 6470 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) |
| 6471 ** cause sqlite3_mutex_alloc() to create |
| 6472 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE |
| 6473 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. |
| 6474 ** The mutex implementation does not need to make a distinction |
| 6475 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does |
| 6476 ** not want to. SQLite will only request a recursive mutex in |
| 6477 ** cases where it really needs one. If a faster non-recursive mutex |
| 6478 ** implementation is available on the host platform, the mutex subsystem |
| 6479 ** might return such a mutex in response to SQLITE_MUTEX_FAST. |
| 6480 ** |
| 6481 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other |
| 6482 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return |
| 6483 ** a pointer to a static preexisting mutex. ^Nine static mutexes are |
| 6484 ** used by the current version of SQLite. Future versions of SQLite |
| 6485 ** may add additional static mutexes. Static mutexes are for internal |
| 6486 ** use by SQLite only. Applications that use SQLite mutexes should |
| 6487 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or |
| 6488 ** SQLITE_MUTEX_RECURSIVE. |
| 6489 ** |
| 6490 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST |
| 6491 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() |
| 6492 ** returns a different mutex on every call. ^For the static |
| 6493 ** mutex types, the same mutex is returned on every call that has |
| 6494 ** the same type number. |
| 6495 ** |
| 6496 ** ^The sqlite3_mutex_free() routine deallocates a previously |
| 6497 ** allocated dynamic mutex. Attempting to deallocate a static |
| 6498 ** mutex results in undefined behavior. |
| 6499 ** |
| 6500 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt |
| 6501 ** to enter a mutex. ^If another thread is already within the mutex, |
| 6502 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return |
| 6503 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] |
| 6504 ** upon successful entry. ^(Mutexes created using |
| 6505 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. |
| 6506 ** In such cases, the |
| 6507 ** mutex must be exited an equal number of times before another thread |
| 6508 ** can enter.)^ If the same thread tries to enter any mutex other |
| 6509 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. |
| 6510 ** |
| 6511 ** ^(Some systems (for example, Windows 95) do not support the operation |
| 6512 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() |
| 6513 ** will always return SQLITE_BUSY. The SQLite core only ever uses |
| 6514 ** sqlite3_mutex_try() as an optimization so this is acceptable |
| 6515 ** behavior.)^ |
| 6516 ** |
| 6517 ** ^The sqlite3_mutex_leave() routine exits a mutex that was |
| 6518 ** previously entered by the same thread. The behavior |
| 6519 ** is undefined if the mutex is not currently entered by the |
| 6520 ** calling thread or is not currently allocated. |
| 6521 ** |
| 6522 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or |
| 6523 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines |
| 6524 ** behave as no-ops. |
| 6525 ** |
| 6526 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. |
| 6527 */ |
| 6528 sqlite3_mutex *sqlite3_mutex_alloc(int); |
| 6529 void sqlite3_mutex_free(sqlite3_mutex*); |
| 6530 void sqlite3_mutex_enter(sqlite3_mutex*); |
| 6531 int sqlite3_mutex_try(sqlite3_mutex*); |
| 6532 void sqlite3_mutex_leave(sqlite3_mutex*); |
| 6533 |
| 6534 /* |
| 6535 ** CAPI3REF: Mutex Methods Object |
| 6536 ** |
| 6537 ** An instance of this structure defines the low-level routines |
| 6538 ** used to allocate and use mutexes. |
| 6539 ** |
| 6540 ** Usually, the default mutex implementations provided by SQLite are |
| 6541 ** sufficient, however the application has the option of substituting a custom |
| 6542 ** implementation for specialized deployments or systems for which SQLite |
| 6543 ** does not provide a suitable implementation. In this case, the application |
| 6544 ** creates and populates an instance of this structure to pass |
| 6545 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. |
| 6546 ** Additionally, an instance of this structure can be used as an |
| 6547 ** output variable when querying the system for the current mutex |
| 6548 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. |
| 6549 ** |
| 6550 ** ^The xMutexInit method defined by this structure is invoked as |
| 6551 ** part of system initialization by the sqlite3_initialize() function. |
| 6552 ** ^The xMutexInit routine is called by SQLite exactly once for each |
| 6553 ** effective call to [sqlite3_initialize()]. |
| 6554 ** |
| 6555 ** ^The xMutexEnd method defined by this structure is invoked as |
| 6556 ** part of system shutdown by the sqlite3_shutdown() function. The |
| 6557 ** implementation of this method is expected to release all outstanding |
| 6558 ** resources obtained by the mutex methods implementation, especially |
| 6559 ** those obtained by the xMutexInit method. ^The xMutexEnd() |
| 6560 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. |
| 6561 ** |
| 6562 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, |
| 6563 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and |
| 6564 ** xMutexNotheld) implement the following interfaces (respectively): |
| 6565 ** |
| 6566 ** <ul> |
| 6567 ** <li> [sqlite3_mutex_alloc()] </li> |
| 6568 ** <li> [sqlite3_mutex_free()] </li> |
| 6569 ** <li> [sqlite3_mutex_enter()] </li> |
| 6570 ** <li> [sqlite3_mutex_try()] </li> |
| 6571 ** <li> [sqlite3_mutex_leave()] </li> |
| 6572 ** <li> [sqlite3_mutex_held()] </li> |
| 6573 ** <li> [sqlite3_mutex_notheld()] </li> |
| 6574 ** </ul>)^ |
| 6575 ** |
| 6576 ** The only difference is that the public sqlite3_XXX functions enumerated |
| 6577 ** above silently ignore any invocations that pass a NULL pointer instead |
| 6578 ** of a valid mutex handle. The implementations of the methods defined |
| 6579 ** by this structure are not required to handle this case, the results |
| 6580 ** of passing a NULL pointer instead of a valid mutex handle are undefined |
| 6581 ** (i.e. it is acceptable to provide an implementation that segfaults if |
| 6582 ** it is passed a NULL pointer). |
| 6583 ** |
| 6584 ** The xMutexInit() method must be threadsafe. It must be harmless to |
| 6585 ** invoke xMutexInit() multiple times within the same process and without |
| 6586 ** intervening calls to xMutexEnd(). Second and subsequent calls to |
| 6587 ** xMutexInit() must be no-ops. |
| 6588 ** |
| 6589 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] |
| 6590 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory |
| 6591 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite |
| 6592 ** memory allocation for a fast or recursive mutex. |
| 6593 ** |
| 6594 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is |
| 6595 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. |
| 6596 ** If xMutexInit fails in any way, it is expected to clean up after itself |
| 6597 ** prior to returning. |
| 6598 */ |
| 6599 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; |
| 6600 struct sqlite3_mutex_methods { |
| 6601 int (*xMutexInit)(void); |
| 6602 int (*xMutexEnd)(void); |
| 6603 sqlite3_mutex *(*xMutexAlloc)(int); |
| 6604 void (*xMutexFree)(sqlite3_mutex *); |
| 6605 void (*xMutexEnter)(sqlite3_mutex *); |
| 6606 int (*xMutexTry)(sqlite3_mutex *); |
| 6607 void (*xMutexLeave)(sqlite3_mutex *); |
| 6608 int (*xMutexHeld)(sqlite3_mutex *); |
| 6609 int (*xMutexNotheld)(sqlite3_mutex *); |
| 6610 }; |
| 6611 |
| 6612 /* |
| 6613 ** CAPI3REF: Mutex Verification Routines |
| 6614 ** |
| 6615 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines |
| 6616 ** are intended for use inside assert() statements. The SQLite core |
| 6617 ** never uses these routines except inside an assert() and applications |
| 6618 ** are advised to follow the lead of the core. The SQLite core only |
| 6619 ** provides implementations for these routines when it is compiled |
| 6620 ** with the SQLITE_DEBUG flag. External mutex implementations |
| 6621 ** are only required to provide these routines if SQLITE_DEBUG is |
| 6622 ** defined and if NDEBUG is not defined. |
| 6623 ** |
| 6624 ** These routines should return true if the mutex in their argument |
| 6625 ** is held or not held, respectively, by the calling thread. |
| 6626 ** |
| 6627 ** The implementation is not required to provide versions of these |
| 6628 ** routines that actually work. If the implementation does not provide working |
| 6629 ** versions of these routines, it should at least provide stubs that always |
| 6630 ** return true so that one does not get spurious assertion failures. |
| 6631 ** |
| 6632 ** If the argument to sqlite3_mutex_held() is a NULL pointer then |
| 6633 ** the routine should return 1. This seems counter-intuitive since |
| 6634 ** clearly the mutex cannot be held if it does not exist. But |
| 6635 ** the reason the mutex does not exist is because the build is not |
| 6636 ** using mutexes. And we do not want the assert() containing the |
| 6637 ** call to sqlite3_mutex_held() to fail, so a non-zero return is |
| 6638 ** the appropriate thing to do. The sqlite3_mutex_notheld() |
| 6639 ** interface should also return 1 when given a NULL pointer. |
| 6640 */ |
| 6641 #ifndef NDEBUG |
| 6642 int sqlite3_mutex_held(sqlite3_mutex*); |
| 6643 int sqlite3_mutex_notheld(sqlite3_mutex*); |
| 6644 #endif |
| 6645 |
| 6646 /* |
| 6647 ** CAPI3REF: Mutex Types |
| 6648 ** |
| 6649 ** The [sqlite3_mutex_alloc()] interface takes a single argument |
| 6650 ** which is one of these integer constants. |
| 6651 ** |
| 6652 ** The set of static mutexes may change from one SQLite release to the |
| 6653 ** next. Applications that override the built-in mutex logic must be |
| 6654 ** prepared to accommodate additional static mutexes. |
| 6655 */ |
| 6656 #define SQLITE_MUTEX_FAST 0 |
| 6657 #define SQLITE_MUTEX_RECURSIVE 1 |
| 6658 #define SQLITE_MUTEX_STATIC_MASTER 2 |
| 6659 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ |
| 6660 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ |
| 6661 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ |
| 6662 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ |
| 6663 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ |
| 6664 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ |
| 6665 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ |
| 6666 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ |
| 6667 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ |
| 6668 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ |
| 6669 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ |
| 6670 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ |
| 6671 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ |
| 6672 |
| 6673 /* |
| 6674 ** CAPI3REF: Retrieve the mutex for a database connection |
| 6675 ** METHOD: sqlite3 |
| 6676 ** |
| 6677 ** ^This interface returns a pointer the [sqlite3_mutex] object that |
| 6678 ** serializes access to the [database connection] given in the argument |
| 6679 ** when the [threading mode] is Serialized. |
| 6680 ** ^If the [threading mode] is Single-thread or Multi-thread then this |
| 6681 ** routine returns a NULL pointer. |
| 6682 */ |
| 6683 sqlite3_mutex *sqlite3_db_mutex(sqlite3*); |
| 6684 |
| 6685 /* |
| 6686 ** CAPI3REF: Low-Level Control Of Database Files |
| 6687 ** METHOD: sqlite3 |
| 6688 ** |
| 6689 ** ^The [sqlite3_file_control()] interface makes a direct call to the |
| 6690 ** xFileControl method for the [sqlite3_io_methods] object associated |
| 6691 ** with a particular database identified by the second argument. ^The |
| 6692 ** name of the database is "main" for the main database or "temp" for the |
| 6693 ** TEMP database, or the name that appears after the AS keyword for |
| 6694 ** databases that are added using the [ATTACH] SQL command. |
| 6695 ** ^A NULL pointer can be used in place of "main" to refer to the |
| 6696 ** main database file. |
| 6697 ** ^The third and fourth parameters to this routine |
| 6698 ** are passed directly through to the second and third parameters of |
| 6699 ** the xFileControl method. ^The return value of the xFileControl |
| 6700 ** method becomes the return value of this routine. |
| 6701 ** |
| 6702 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes |
| 6703 ** a pointer to the underlying [sqlite3_file] object to be written into |
| 6704 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER |
| 6705 ** case is a short-circuit path which does not actually invoke the |
| 6706 ** underlying sqlite3_io_methods.xFileControl method. |
| 6707 ** |
| 6708 ** ^If the second parameter (zDbName) does not match the name of any |
| 6709 ** open database file, then SQLITE_ERROR is returned. ^This error |
| 6710 ** code is not remembered and will not be recalled by [sqlite3_errcode()] |
| 6711 ** or [sqlite3_errmsg()]. The underlying xFileControl method might |
| 6712 ** also return SQLITE_ERROR. There is no way to distinguish between |
| 6713 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying |
| 6714 ** xFileControl method. |
| 6715 ** |
| 6716 ** See also: [SQLITE_FCNTL_LOCKSTATE] |
| 6717 */ |
| 6718 int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); |
| 6719 |
| 6720 /* |
| 6721 ** CAPI3REF: Testing Interface |
| 6722 ** |
| 6723 ** ^The sqlite3_test_control() interface is used to read out internal |
| 6724 ** state of SQLite and to inject faults into SQLite for testing |
| 6725 ** purposes. ^The first parameter is an operation code that determines |
| 6726 ** the number, meaning, and operation of all subsequent parameters. |
| 6727 ** |
| 6728 ** This interface is not for use by applications. It exists solely |
| 6729 ** for verifying the correct operation of the SQLite library. Depending |
| 6730 ** on how the SQLite library is compiled, this interface might not exist. |
| 6731 ** |
| 6732 ** The details of the operation codes, their meanings, the parameters |
| 6733 ** they take, and what they do are all subject to change without notice. |
| 6734 ** Unlike most of the SQLite API, this function is not guaranteed to |
| 6735 ** operate consistently from one release to the next. |
| 6736 */ |
| 6737 int sqlite3_test_control(int op, ...); |
| 6738 |
| 6739 /* |
| 6740 ** CAPI3REF: Testing Interface Operation Codes |
| 6741 ** |
| 6742 ** These constants are the valid operation code parameters used |
| 6743 ** as the first argument to [sqlite3_test_control()]. |
| 6744 ** |
| 6745 ** These parameters and their meanings are subject to change |
| 6746 ** without notice. These values are for testing purposes only. |
| 6747 ** Applications should not use any of these parameters or the |
| 6748 ** [sqlite3_test_control()] interface. |
| 6749 */ |
| 6750 #define SQLITE_TESTCTRL_FIRST 5 |
| 6751 #define SQLITE_TESTCTRL_PRNG_SAVE 5 |
| 6752 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 |
| 6753 #define SQLITE_TESTCTRL_PRNG_RESET 7 |
| 6754 #define SQLITE_TESTCTRL_BITVEC_TEST 8 |
| 6755 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 |
| 6756 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 |
| 6757 #define SQLITE_TESTCTRL_PENDING_BYTE 11 |
| 6758 #define SQLITE_TESTCTRL_ASSERT 12 |
| 6759 #define SQLITE_TESTCTRL_ALWAYS 13 |
| 6760 #define SQLITE_TESTCTRL_RESERVE 14 |
| 6761 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 |
| 6762 #define SQLITE_TESTCTRL_ISKEYWORD 16 |
| 6763 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 |
| 6764 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 |
| 6765 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ |
| 6766 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 |
| 6767 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 |
| 6768 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 |
| 6769 #define SQLITE_TESTCTRL_BYTEORDER 22 |
| 6770 #define SQLITE_TESTCTRL_ISINIT 23 |
| 6771 #define SQLITE_TESTCTRL_SORTER_MMAP 24 |
| 6772 #define SQLITE_TESTCTRL_IMPOSTER 25 |
| 6773 #define SQLITE_TESTCTRL_LAST 25 |
| 6774 |
| 6775 /* |
| 6776 ** CAPI3REF: SQLite Runtime Status |
| 6777 ** |
| 6778 ** ^These interfaces are used to retrieve runtime status information |
| 6779 ** about the performance of SQLite, and optionally to reset various |
| 6780 ** highwater marks. ^The first argument is an integer code for |
| 6781 ** the specific parameter to measure. ^(Recognized integer codes |
| 6782 ** are of the form [status parameters | SQLITE_STATUS_...].)^ |
| 6783 ** ^The current value of the parameter is returned into *pCurrent. |
| 6784 ** ^The highest recorded value is returned in *pHighwater. ^If the |
| 6785 ** resetFlag is true, then the highest record value is reset after |
| 6786 ** *pHighwater is written. ^(Some parameters do not record the highest |
| 6787 ** value. For those parameters |
| 6788 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ |
| 6789 ** ^(Other parameters record only the highwater mark and not the current |
| 6790 ** value. For these latter parameters nothing is written into *pCurrent.)^ |
| 6791 ** |
| 6792 ** ^The sqlite3_status() and sqlite3_status64() routines return |
| 6793 ** SQLITE_OK on success and a non-zero [error code] on failure. |
| 6794 ** |
| 6795 ** If either the current value or the highwater mark is too large to |
| 6796 ** be represented by a 32-bit integer, then the values returned by |
| 6797 ** sqlite3_status() are undefined. |
| 6798 ** |
| 6799 ** See also: [sqlite3_db_status()] |
| 6800 */ |
| 6801 int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); |
| 6802 int sqlite3_status64( |
| 6803 int op, |
| 6804 sqlite3_int64 *pCurrent, |
| 6805 sqlite3_int64 *pHighwater, |
| 6806 int resetFlag |
| 6807 ); |
| 6808 |
| 6809 |
| 6810 /* |
| 6811 ** CAPI3REF: Status Parameters |
| 6812 ** KEYWORDS: {status parameters} |
| 6813 ** |
| 6814 ** These integer constants designate various run-time status parameters |
| 6815 ** that can be returned by [sqlite3_status()]. |
| 6816 ** |
| 6817 ** <dl> |
| 6818 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> |
| 6819 ** <dd>This parameter is the current amount of memory checked out |
| 6820 ** using [sqlite3_malloc()], either directly or indirectly. The |
| 6821 ** figure includes calls made to [sqlite3_malloc()] by the application |
| 6822 ** and internal memory usage by the SQLite library. Scratch memory |
| 6823 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache |
| 6824 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in |
| 6825 ** this parameter. The amount returned is the sum of the allocation |
| 6826 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ |
| 6827 ** |
| 6828 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> |
| 6829 ** <dd>This parameter records the largest memory allocation request |
| 6830 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their |
| 6831 ** internal equivalents). Only the value returned in the |
| 6832 ** *pHighwater parameter to [sqlite3_status()] is of interest. |
| 6833 ** The value written into the *pCurrent parameter is undefined.</dd>)^ |
| 6834 ** |
| 6835 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> |
| 6836 ** <dd>This parameter records the number of separate memory allocations |
| 6837 ** currently checked out.</dd>)^ |
| 6838 ** |
| 6839 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> |
| 6840 ** <dd>This parameter returns the number of pages used out of the |
| 6841 ** [pagecache memory allocator] that was configured using |
| 6842 ** [SQLITE_CONFIG_PAGECACHE]. The |
| 6843 ** value returned is in pages, not in bytes.</dd>)^ |
| 6844 ** |
| 6845 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] |
| 6846 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> |
| 6847 ** <dd>This parameter returns the number of bytes of page cache |
| 6848 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] |
| 6849 ** buffer and where forced to overflow to [sqlite3_malloc()]. The |
| 6850 ** returned value includes allocations that overflowed because they |
| 6851 ** where too large (they were larger than the "sz" parameter to |
| 6852 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because |
| 6853 ** no space was left in the page cache.</dd>)^ |
| 6854 ** |
| 6855 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> |
| 6856 ** <dd>This parameter records the largest memory allocation request |
| 6857 ** handed to [pagecache memory allocator]. Only the value returned in the |
| 6858 ** *pHighwater parameter to [sqlite3_status()] is of interest. |
| 6859 ** The value written into the *pCurrent parameter is undefined.</dd>)^ |
| 6860 ** |
| 6861 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> |
| 6862 ** <dd>This parameter returns the number of allocations used out of the |
| 6863 ** [scratch memory allocator] configured using |
| 6864 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not |
| 6865 ** in bytes. Since a single thread may only have one scratch allocation |
| 6866 ** outstanding at time, this parameter also reports the number of threads |
| 6867 ** using scratch memory at the same time.</dd>)^ |
| 6868 ** |
| 6869 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> |
| 6870 ** <dd>This parameter returns the number of bytes of scratch memory |
| 6871 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] |
| 6872 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values |
| 6873 ** returned include overflows because the requested allocation was too |
| 6874 ** larger (that is, because the requested allocation was larger than the |
| 6875 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer |
| 6876 ** slots were available. |
| 6877 ** </dd>)^ |
| 6878 ** |
| 6879 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> |
| 6880 ** <dd>This parameter records the largest memory allocation request |
| 6881 ** handed to [scratch memory allocator]. Only the value returned in the |
| 6882 ** *pHighwater parameter to [sqlite3_status()] is of interest. |
| 6883 ** The value written into the *pCurrent parameter is undefined.</dd>)^ |
| 6884 ** |
| 6885 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> |
| 6886 ** <dd>The *pHighwater parameter records the deepest parser stack. |
| 6887 ** The *pCurrent value is undefined. The *pHighwater value is only |
| 6888 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ |
| 6889 ** </dl> |
| 6890 ** |
| 6891 ** New status parameters may be added from time to time. |
| 6892 */ |
| 6893 #define SQLITE_STATUS_MEMORY_USED 0 |
| 6894 #define SQLITE_STATUS_PAGECACHE_USED 1 |
| 6895 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 |
| 6896 #define SQLITE_STATUS_SCRATCH_USED 3 |
| 6897 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 |
| 6898 #define SQLITE_STATUS_MALLOC_SIZE 5 |
| 6899 #define SQLITE_STATUS_PARSER_STACK 6 |
| 6900 #define SQLITE_STATUS_PAGECACHE_SIZE 7 |
| 6901 #define SQLITE_STATUS_SCRATCH_SIZE 8 |
| 6902 #define SQLITE_STATUS_MALLOC_COUNT 9 |
| 6903 |
| 6904 /* |
| 6905 ** CAPI3REF: Database Connection Status |
| 6906 ** METHOD: sqlite3 |
| 6907 ** |
| 6908 ** ^This interface is used to retrieve runtime status information |
| 6909 ** about a single [database connection]. ^The first argument is the |
| 6910 ** database connection object to be interrogated. ^The second argument |
| 6911 ** is an integer constant, taken from the set of |
| 6912 ** [SQLITE_DBSTATUS options], that |
| 6913 ** determines the parameter to interrogate. The set of |
| 6914 ** [SQLITE_DBSTATUS options] is likely |
| 6915 ** to grow in future releases of SQLite. |
| 6916 ** |
| 6917 ** ^The current value of the requested parameter is written into *pCur |
| 6918 ** and the highest instantaneous value is written into *pHiwtr. ^If |
| 6919 ** the resetFlg is true, then the highest instantaneous value is |
| 6920 ** reset back down to the current value. |
| 6921 ** |
| 6922 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a |
| 6923 ** non-zero [error code] on failure. |
| 6924 ** |
| 6925 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. |
| 6926 */ |
| 6927 int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); |
| 6928 |
| 6929 /* |
| 6930 ** CAPI3REF: Status Parameters for database connections |
| 6931 ** KEYWORDS: {SQLITE_DBSTATUS options} |
| 6932 ** |
| 6933 ** These constants are the available integer "verbs" that can be passed as |
| 6934 ** the second argument to the [sqlite3_db_status()] interface. |
| 6935 ** |
| 6936 ** New verbs may be added in future releases of SQLite. Existing verbs |
| 6937 ** might be discontinued. Applications should check the return code from |
| 6938 ** [sqlite3_db_status()] to make sure that the call worked. |
| 6939 ** The [sqlite3_db_status()] interface will return a non-zero error code |
| 6940 ** if a discontinued or unsupported verb is invoked. |
| 6941 ** |
| 6942 ** <dl> |
| 6943 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> |
| 6944 ** <dd>This parameter returns the number of lookaside memory slots currently |
| 6945 ** checked out.</dd>)^ |
| 6946 ** |
| 6947 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> |
| 6948 ** <dd>This parameter returns the number malloc attempts that were |
| 6949 ** satisfied using lookaside memory. Only the high-water value is meaningful; |
| 6950 ** the current value is always zero.)^ |
| 6951 ** |
| 6952 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] |
| 6953 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> |
| 6954 ** <dd>This parameter returns the number malloc attempts that might have |
| 6955 ** been satisfied using lookaside memory but failed due to the amount of |
| 6956 ** memory requested being larger than the lookaside slot size. |
| 6957 ** Only the high-water value is meaningful; |
| 6958 ** the current value is always zero.)^ |
| 6959 ** |
| 6960 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] |
| 6961 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> |
| 6962 ** <dd>This parameter returns the number malloc attempts that might have |
| 6963 ** been satisfied using lookaside memory but failed due to all lookaside |
| 6964 ** memory already being in use. |
| 6965 ** Only the high-water value is meaningful; |
| 6966 ** the current value is always zero.)^ |
| 6967 ** |
| 6968 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> |
| 6969 ** <dd>This parameter returns the approximate number of bytes of heap |
| 6970 ** memory used by all pager caches associated with the database connection.)^ |
| 6971 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. |
| 6972 ** |
| 6973 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] |
| 6974 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> |
| 6975 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a |
| 6976 ** pager cache is shared between two or more connections the bytes of heap |
| 6977 ** memory used by that pager cache is divided evenly between the attached |
| 6978 ** connections.)^ In other words, if none of the pager caches associated |
| 6979 ** with the database connection are shared, this request returns the same |
| 6980 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are |
| 6981 ** shared, the value returned by this call will be smaller than that returned |
| 6982 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with |
| 6983 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. |
| 6984 ** |
| 6985 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> |
| 6986 ** <dd>This parameter returns the approximate number of bytes of heap |
| 6987 ** memory used to store the schema for all databases associated |
| 6988 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ |
| 6989 ** ^The full amount of memory used by the schemas is reported, even if the |
| 6990 ** schema memory is shared with other database connections due to |
| 6991 ** [shared cache mode] being enabled. |
| 6992 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. |
| 6993 ** |
| 6994 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> |
| 6995 ** <dd>This parameter returns the approximate number of bytes of heap |
| 6996 ** and lookaside memory used by all prepared statements associated with |
| 6997 ** the database connection.)^ |
| 6998 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. |
| 6999 ** </dd> |
| 7000 ** |
| 7001 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> |
| 7002 ** <dd>This parameter returns the number of pager cache hits that have |
| 7003 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT |
| 7004 ** is always 0. |
| 7005 ** </dd> |
| 7006 ** |
| 7007 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> |
| 7008 ** <dd>This parameter returns the number of pager cache misses that have |
| 7009 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS |
| 7010 ** is always 0. |
| 7011 ** </dd> |
| 7012 ** |
| 7013 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> |
| 7014 ** <dd>This parameter returns the number of dirty cache entries that have |
| 7015 ** been written to disk. Specifically, the number of pages written to the |
| 7016 ** wal file in wal mode databases, or the number of pages written to the |
| 7017 ** database file in rollback mode databases. Any pages written as part of |
| 7018 ** transaction rollback or database recovery operations are not included. |
| 7019 ** If an IO or other error occurs while writing a page to disk, the effect |
| 7020 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The |
| 7021 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. |
| 7022 ** </dd> |
| 7023 ** |
| 7024 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> |
| 7025 ** <dd>This parameter returns zero for the current value if and only if |
| 7026 ** all foreign key constraints (deferred or immediate) have been |
| 7027 ** resolved.)^ ^The highwater mark is always 0. |
| 7028 ** </dd> |
| 7029 ** </dl> |
| 7030 */ |
| 7031 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 |
| 7032 #define SQLITE_DBSTATUS_CACHE_USED 1 |
| 7033 #define SQLITE_DBSTATUS_SCHEMA_USED 2 |
| 7034 #define SQLITE_DBSTATUS_STMT_USED 3 |
| 7035 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 |
| 7036 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 |
| 7037 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 |
| 7038 #define SQLITE_DBSTATUS_CACHE_HIT 7 |
| 7039 #define SQLITE_DBSTATUS_CACHE_MISS 8 |
| 7040 #define SQLITE_DBSTATUS_CACHE_WRITE 9 |
| 7041 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 |
| 7042 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 |
| 7043 #define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ |
| 7044 |
| 7045 |
| 7046 /* |
| 7047 ** CAPI3REF: Prepared Statement Status |
| 7048 ** METHOD: sqlite3_stmt |
| 7049 ** |
| 7050 ** ^(Each prepared statement maintains various |
| 7051 ** [SQLITE_STMTSTATUS counters] that measure the number |
| 7052 ** of times it has performed specific operations.)^ These counters can |
| 7053 ** be used to monitor the performance characteristics of the prepared |
| 7054 ** statements. For example, if the number of table steps greatly exceeds |
| 7055 ** the number of table searches or result rows, that would tend to indicate |
| 7056 ** that the prepared statement is using a full table scan rather than |
| 7057 ** an index. |
| 7058 ** |
| 7059 ** ^(This interface is used to retrieve and reset counter values from |
| 7060 ** a [prepared statement]. The first argument is the prepared statement |
| 7061 ** object to be interrogated. The second argument |
| 7062 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] |
| 7063 ** to be interrogated.)^ |
| 7064 ** ^The current value of the requested counter is returned. |
| 7065 ** ^If the resetFlg is true, then the counter is reset to zero after this |
| 7066 ** interface call returns. |
| 7067 ** |
| 7068 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. |
| 7069 */ |
| 7070 int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); |
| 7071 |
| 7072 /* |
| 7073 ** CAPI3REF: Status Parameters for prepared statements |
| 7074 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} |
| 7075 ** |
| 7076 ** These preprocessor macros define integer codes that name counter |
| 7077 ** values associated with the [sqlite3_stmt_status()] interface. |
| 7078 ** The meanings of the various counters are as follows: |
| 7079 ** |
| 7080 ** <dl> |
| 7081 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> |
| 7082 ** <dd>^This is the number of times that SQLite has stepped forward in |
| 7083 ** a table as part of a full table scan. Large numbers for this counter |
| 7084 ** may indicate opportunities for performance improvement through |
| 7085 ** careful use of indices.</dd> |
| 7086 ** |
| 7087 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> |
| 7088 ** <dd>^This is the number of sort operations that have occurred. |
| 7089 ** A non-zero value in this counter may indicate an opportunity to |
| 7090 ** improvement performance through careful use of indices.</dd> |
| 7091 ** |
| 7092 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> |
| 7093 ** <dd>^This is the number of rows inserted into transient indices that |
| 7094 ** were created automatically in order to help joins run faster. |
| 7095 ** A non-zero value in this counter may indicate an opportunity to |
| 7096 ** improvement performance by adding permanent indices that do not |
| 7097 ** need to be reinitialized each time the statement is run.</dd> |
| 7098 ** |
| 7099 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> |
| 7100 ** <dd>^This is the number of virtual machine operations executed |
| 7101 ** by the prepared statement if that number is less than or equal |
| 7102 ** to 2147483647. The number of virtual machine operations can be |
| 7103 ** used as a proxy for the total work done by the prepared statement. |
| 7104 ** If the number of virtual machine operations exceeds 2147483647 |
| 7105 ** then the value returned by this statement status code is undefined. |
| 7106 ** </dd> |
| 7107 ** </dl> |
| 7108 */ |
| 7109 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 |
| 7110 #define SQLITE_STMTSTATUS_SORT 2 |
| 7111 #define SQLITE_STMTSTATUS_AUTOINDEX 3 |
| 7112 #define SQLITE_STMTSTATUS_VM_STEP 4 |
| 7113 |
| 7114 /* |
| 7115 ** CAPI3REF: Custom Page Cache Object |
| 7116 ** |
| 7117 ** The sqlite3_pcache type is opaque. It is implemented by |
| 7118 ** the pluggable module. The SQLite core has no knowledge of |
| 7119 ** its size or internal structure and never deals with the |
| 7120 ** sqlite3_pcache object except by holding and passing pointers |
| 7121 ** to the object. |
| 7122 ** |
| 7123 ** See [sqlite3_pcache_methods2] for additional information. |
| 7124 */ |
| 7125 typedef struct sqlite3_pcache sqlite3_pcache; |
| 7126 |
| 7127 /* |
| 7128 ** CAPI3REF: Custom Page Cache Object |
| 7129 ** |
| 7130 ** The sqlite3_pcache_page object represents a single page in the |
| 7131 ** page cache. The page cache will allocate instances of this |
| 7132 ** object. Various methods of the page cache use pointers to instances |
| 7133 ** of this object as parameters or as their return value. |
| 7134 ** |
| 7135 ** See [sqlite3_pcache_methods2] for additional information. |
| 7136 */ |
| 7137 typedef struct sqlite3_pcache_page sqlite3_pcache_page; |
| 7138 struct sqlite3_pcache_page { |
| 7139 void *pBuf; /* The content of the page */ |
| 7140 void *pExtra; /* Extra information associated with the page */ |
| 7141 }; |
| 7142 |
| 7143 /* |
| 7144 ** CAPI3REF: Application Defined Page Cache. |
| 7145 ** KEYWORDS: {page cache} |
| 7146 ** |
| 7147 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can |
| 7148 ** register an alternative page cache implementation by passing in an |
| 7149 ** instance of the sqlite3_pcache_methods2 structure.)^ |
| 7150 ** In many applications, most of the heap memory allocated by |
| 7151 ** SQLite is used for the page cache. |
| 7152 ** By implementing a |
| 7153 ** custom page cache using this API, an application can better control |
| 7154 ** the amount of memory consumed by SQLite, the way in which |
| 7155 ** that memory is allocated and released, and the policies used to |
| 7156 ** determine exactly which parts of a database file are cached and for |
| 7157 ** how long. |
| 7158 ** |
| 7159 ** The alternative page cache mechanism is an |
| 7160 ** extreme measure that is only needed by the most demanding applications. |
| 7161 ** The built-in page cache is recommended for most uses. |
| 7162 ** |
| 7163 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an |
| 7164 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence |
| 7165 ** the application may discard the parameter after the call to |
| 7166 ** [sqlite3_config()] returns.)^ |
| 7167 ** |
| 7168 ** [[the xInit() page cache method]] |
| 7169 ** ^(The xInit() method is called once for each effective |
| 7170 ** call to [sqlite3_initialize()])^ |
| 7171 ** (usually only once during the lifetime of the process). ^(The xInit() |
| 7172 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ |
| 7173 ** The intent of the xInit() method is to set up global data structures |
| 7174 ** required by the custom page cache implementation. |
| 7175 ** ^(If the xInit() method is NULL, then the |
| 7176 ** built-in default page cache is used instead of the application defined |
| 7177 ** page cache.)^ |
| 7178 ** |
| 7179 ** [[the xShutdown() page cache method]] |
| 7180 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. |
| 7181 ** It can be used to clean up |
| 7182 ** any outstanding resources before process shutdown, if required. |
| 7183 ** ^The xShutdown() method may be NULL. |
| 7184 ** |
| 7185 ** ^SQLite automatically serializes calls to the xInit method, |
| 7186 ** so the xInit method need not be threadsafe. ^The |
| 7187 ** xShutdown method is only called from [sqlite3_shutdown()] so it does |
| 7188 ** not need to be threadsafe either. All other methods must be threadsafe |
| 7189 ** in multithreaded applications. |
| 7190 ** |
| 7191 ** ^SQLite will never invoke xInit() more than once without an intervening |
| 7192 ** call to xShutdown(). |
| 7193 ** |
| 7194 ** [[the xCreate() page cache methods]] |
| 7195 ** ^SQLite invokes the xCreate() method to construct a new cache instance. |
| 7196 ** SQLite will typically create one cache instance for each open database file, |
| 7197 ** though this is not guaranteed. ^The |
| 7198 ** first parameter, szPage, is the size in bytes of the pages that must |
| 7199 ** be allocated by the cache. ^szPage will always a power of two. ^The |
| 7200 ** second parameter szExtra is a number of bytes of extra storage |
| 7201 ** associated with each page cache entry. ^The szExtra parameter will |
| 7202 ** a number less than 250. SQLite will use the |
| 7203 ** extra szExtra bytes on each page to store metadata about the underlying |
| 7204 ** database page on disk. The value passed into szExtra depends |
| 7205 ** on the SQLite version, the target platform, and how SQLite was compiled. |
| 7206 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being |
| 7207 ** created will be used to cache database pages of a file stored on disk, or |
| 7208 ** false if it is used for an in-memory database. The cache implementation |
| 7209 ** does not have to do anything special based with the value of bPurgeable; |
| 7210 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will |
| 7211 ** never invoke xUnpin() except to deliberately delete a page. |
| 7212 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to |
| 7213 ** false will always have the "discard" flag set to true. |
| 7214 ** ^Hence, a cache created with bPurgeable false will |
| 7215 ** never contain any unpinned pages. |
| 7216 ** |
| 7217 ** [[the xCachesize() page cache method]] |
| 7218 ** ^(The xCachesize() method may be called at any time by SQLite to set the |
| 7219 ** suggested maximum cache-size (number of pages stored by) the cache |
| 7220 ** instance passed as the first argument. This is the value configured using |
| 7221 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable |
| 7222 ** parameter, the implementation is not required to do anything with this |
| 7223 ** value; it is advisory only. |
| 7224 ** |
| 7225 ** [[the xPagecount() page cache methods]] |
| 7226 ** The xPagecount() method must return the number of pages currently |
| 7227 ** stored in the cache, both pinned and unpinned. |
| 7228 ** |
| 7229 ** [[the xFetch() page cache methods]] |
| 7230 ** The xFetch() method locates a page in the cache and returns a pointer to |
| 7231 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. |
| 7232 ** The pBuf element of the returned sqlite3_pcache_page object will be a |
| 7233 ** pointer to a buffer of szPage bytes used to store the content of a |
| 7234 ** single database page. The pExtra element of sqlite3_pcache_page will be |
| 7235 ** a pointer to the szExtra bytes of extra storage that SQLite has requested |
| 7236 ** for each entry in the page cache. |
| 7237 ** |
| 7238 ** The page to be fetched is determined by the key. ^The minimum key value |
| 7239 ** is 1. After it has been retrieved using xFetch, the page is considered |
| 7240 ** to be "pinned". |
| 7241 ** |
| 7242 ** If the requested page is already in the page cache, then the page cache |
| 7243 ** implementation must return a pointer to the page buffer with its content |
| 7244 ** intact. If the requested page is not already in the cache, then the |
| 7245 ** cache implementation should use the value of the createFlag |
| 7246 ** parameter to help it determined what action to take: |
| 7247 ** |
| 7248 ** <table border=1 width=85% align=center> |
| 7249 ** <tr><th> createFlag <th> Behavior when page is not already in cache |
| 7250 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. |
| 7251 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. |
| 7252 ** Otherwise return NULL. |
| 7253 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return |
| 7254 ** NULL if allocating a new page is effectively impossible. |
| 7255 ** </table> |
| 7256 ** |
| 7257 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite |
| 7258 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 |
| 7259 ** failed.)^ In between the to xFetch() calls, SQLite may |
| 7260 ** attempt to unpin one or more cache pages by spilling the content of |
| 7261 ** pinned pages to disk and synching the operating system disk cache. |
| 7262 ** |
| 7263 ** [[the xUnpin() page cache method]] |
| 7264 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page |
| 7265 ** as its second argument. If the third parameter, discard, is non-zero, |
| 7266 ** then the page must be evicted from the cache. |
| 7267 ** ^If the discard parameter is |
| 7268 ** zero, then the page may be discarded or retained at the discretion of |
| 7269 ** page cache implementation. ^The page cache implementation |
| 7270 ** may choose to evict unpinned pages at any time. |
| 7271 ** |
| 7272 ** The cache must not perform any reference counting. A single |
| 7273 ** call to xUnpin() unpins the page regardless of the number of prior calls |
| 7274 ** to xFetch(). |
| 7275 ** |
| 7276 ** [[the xRekey() page cache methods]] |
| 7277 ** The xRekey() method is used to change the key value associated with the |
| 7278 ** page passed as the second argument. If the cache |
| 7279 ** previously contains an entry associated with newKey, it must be |
| 7280 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not |
| 7281 ** to be pinned. |
| 7282 ** |
| 7283 ** When SQLite calls the xTruncate() method, the cache must discard all |
| 7284 ** existing cache entries with page numbers (keys) greater than or equal |
| 7285 ** to the value of the iLimit parameter passed to xTruncate(). If any |
| 7286 ** of these pages are pinned, they are implicitly unpinned, meaning that |
| 7287 ** they can be safely discarded. |
| 7288 ** |
| 7289 ** [[the xDestroy() page cache method]] |
| 7290 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). |
| 7291 ** All resources associated with the specified cache should be freed. ^After |
| 7292 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] |
| 7293 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 |
| 7294 ** functions. |
| 7295 ** |
| 7296 ** [[the xShrink() page cache method]] |
| 7297 ** ^SQLite invokes the xShrink() method when it wants the page cache to |
| 7298 ** free up as much of heap memory as possible. The page cache implementation |
| 7299 ** is not obligated to free any memory, but well-behaved implementations should |
| 7300 ** do their best. |
| 7301 */ |
| 7302 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; |
| 7303 struct sqlite3_pcache_methods2 { |
| 7304 int iVersion; |
| 7305 void *pArg; |
| 7306 int (*xInit)(void*); |
| 7307 void (*xShutdown)(void*); |
| 7308 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); |
| 7309 void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
| 7310 int (*xPagecount)(sqlite3_pcache*); |
| 7311 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
| 7312 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); |
| 7313 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, |
| 7314 unsigned oldKey, unsigned newKey); |
| 7315 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
| 7316 void (*xDestroy)(sqlite3_pcache*); |
| 7317 void (*xShrink)(sqlite3_pcache*); |
| 7318 }; |
| 7319 |
| 7320 /* |
| 7321 ** This is the obsolete pcache_methods object that has now been replaced |
| 7322 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is |
| 7323 ** retained in the header file for backwards compatibility only. |
| 7324 */ |
| 7325 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; |
| 7326 struct sqlite3_pcache_methods { |
| 7327 void *pArg; |
| 7328 int (*xInit)(void*); |
| 7329 void (*xShutdown)(void*); |
| 7330 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); |
| 7331 void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
| 7332 int (*xPagecount)(sqlite3_pcache*); |
| 7333 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
| 7334 void (*xUnpin)(sqlite3_pcache*, void*, int discard); |
| 7335 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); |
| 7336 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
| 7337 void (*xDestroy)(sqlite3_pcache*); |
| 7338 }; |
| 7339 |
| 7340 |
| 7341 /* |
| 7342 ** CAPI3REF: Online Backup Object |
| 7343 ** |
| 7344 ** The sqlite3_backup object records state information about an ongoing |
| 7345 ** online backup operation. ^The sqlite3_backup object is created by |
| 7346 ** a call to [sqlite3_backup_init()] and is destroyed by a call to |
| 7347 ** [sqlite3_backup_finish()]. |
| 7348 ** |
| 7349 ** See Also: [Using the SQLite Online Backup API] |
| 7350 */ |
| 7351 typedef struct sqlite3_backup sqlite3_backup; |
| 7352 |
| 7353 /* |
| 7354 ** CAPI3REF: Online Backup API. |
| 7355 ** |
| 7356 ** The backup API copies the content of one database into another. |
| 7357 ** It is useful either for creating backups of databases or |
| 7358 ** for copying in-memory databases to or from persistent files. |
| 7359 ** |
| 7360 ** See Also: [Using the SQLite Online Backup API] |
| 7361 ** |
| 7362 ** ^SQLite holds a write transaction open on the destination database file |
| 7363 ** for the duration of the backup operation. |
| 7364 ** ^The source database is read-locked only while it is being read; |
| 7365 ** it is not locked continuously for the entire backup operation. |
| 7366 ** ^Thus, the backup may be performed on a live source database without |
| 7367 ** preventing other database connections from |
| 7368 ** reading or writing to the source database while the backup is underway. |
| 7369 ** |
| 7370 ** ^(To perform a backup operation: |
| 7371 ** <ol> |
| 7372 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the |
| 7373 ** backup, |
| 7374 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer |
| 7375 ** the data between the two databases, and finally |
| 7376 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources |
| 7377 ** associated with the backup operation. |
| 7378 ** </ol>)^ |
| 7379 ** There should be exactly one call to sqlite3_backup_finish() for each |
| 7380 ** successful call to sqlite3_backup_init(). |
| 7381 ** |
| 7382 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> |
| 7383 ** |
| 7384 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the |
| 7385 ** [database connection] associated with the destination database |
| 7386 ** and the database name, respectively. |
| 7387 ** ^The database name is "main" for the main database, "temp" for the |
| 7388 ** temporary database, or the name specified after the AS keyword in |
| 7389 ** an [ATTACH] statement for an attached database. |
| 7390 ** ^The S and M arguments passed to |
| 7391 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] |
| 7392 ** and database name of the source database, respectively. |
| 7393 ** ^The source and destination [database connections] (parameters S and D) |
| 7394 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with |
| 7395 ** an error. |
| 7396 ** |
| 7397 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if |
| 7398 ** there is already a read or read-write transaction open on the |
| 7399 ** destination database. |
| 7400 ** |
| 7401 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is |
| 7402 ** returned and an error code and error message are stored in the |
| 7403 ** destination [database connection] D. |
| 7404 ** ^The error code and message for the failed call to sqlite3_backup_init() |
| 7405 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or |
| 7406 ** [sqlite3_errmsg16()] functions. |
| 7407 ** ^A successful call to sqlite3_backup_init() returns a pointer to an |
| 7408 ** [sqlite3_backup] object. |
| 7409 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and |
| 7410 ** sqlite3_backup_finish() functions to perform the specified backup |
| 7411 ** operation. |
| 7412 ** |
| 7413 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> |
| 7414 ** |
| 7415 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between |
| 7416 ** the source and destination databases specified by [sqlite3_backup] object B. |
| 7417 ** ^If N is negative, all remaining source pages are copied. |
| 7418 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there |
| 7419 ** are still more pages to be copied, then the function returns [SQLITE_OK]. |
| 7420 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages |
| 7421 ** from source to destination, then it returns [SQLITE_DONE]. |
| 7422 ** ^If an error occurs while running sqlite3_backup_step(B,N), |
| 7423 ** then an [error code] is returned. ^As well as [SQLITE_OK] and |
| 7424 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], |
| 7425 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an |
| 7426 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. |
| 7427 ** |
| 7428 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if |
| 7429 ** <ol> |
| 7430 ** <li> the destination database was opened read-only, or |
| 7431 ** <li> the destination database is using write-ahead-log journaling |
| 7432 ** and the destination and source page sizes differ, or |
| 7433 ** <li> the destination database is an in-memory database and the |
| 7434 ** destination and source page sizes differ. |
| 7435 ** </ol>)^ |
| 7436 ** |
| 7437 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then |
| 7438 ** the [sqlite3_busy_handler | busy-handler function] |
| 7439 ** is invoked (if one is specified). ^If the |
| 7440 ** busy-handler returns non-zero before the lock is available, then |
| 7441 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to |
| 7442 ** sqlite3_backup_step() can be retried later. ^If the source |
| 7443 ** [database connection] |
| 7444 ** is being used to write to the source database when sqlite3_backup_step() |
| 7445 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this |
| 7446 ** case the call to sqlite3_backup_step() can be retried later on. ^(If |
| 7447 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or |
| 7448 ** [SQLITE_READONLY] is returned, then |
| 7449 ** there is no point in retrying the call to sqlite3_backup_step(). These |
| 7450 ** errors are considered fatal.)^ The application must accept |
| 7451 ** that the backup operation has failed and pass the backup operation handle |
| 7452 ** to the sqlite3_backup_finish() to release associated resources. |
| 7453 ** |
| 7454 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock |
| 7455 ** on the destination file. ^The exclusive lock is not released until either |
| 7456 ** sqlite3_backup_finish() is called or the backup operation is complete |
| 7457 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to |
| 7458 ** sqlite3_backup_step() obtains a [shared lock] on the source database that |
| 7459 ** lasts for the duration of the sqlite3_backup_step() call. |
| 7460 ** ^Because the source database is not locked between calls to |
| 7461 ** sqlite3_backup_step(), the source database may be modified mid-way |
| 7462 ** through the backup process. ^If the source database is modified by an |
| 7463 ** external process or via a database connection other than the one being |
| 7464 ** used by the backup operation, then the backup will be automatically |
| 7465 ** restarted by the next call to sqlite3_backup_step(). ^If the source |
| 7466 ** database is modified by the using the same database connection as is used |
| 7467 ** by the backup operation, then the backup database is automatically |
| 7468 ** updated at the same time. |
| 7469 ** |
| 7470 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> |
| 7471 ** |
| 7472 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the |
| 7473 ** application wishes to abandon the backup operation, the application |
| 7474 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). |
| 7475 ** ^The sqlite3_backup_finish() interfaces releases all |
| 7476 ** resources associated with the [sqlite3_backup] object. |
| 7477 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any |
| 7478 ** active write-transaction on the destination database is rolled back. |
| 7479 ** The [sqlite3_backup] object is invalid |
| 7480 ** and may not be used following a call to sqlite3_backup_finish(). |
| 7481 ** |
| 7482 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no |
| 7483 ** sqlite3_backup_step() errors occurred, regardless or whether or not |
| 7484 ** sqlite3_backup_step() completed. |
| 7485 ** ^If an out-of-memory condition or IO error occurred during any prior |
| 7486 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then |
| 7487 ** sqlite3_backup_finish() returns the corresponding [error code]. |
| 7488 ** |
| 7489 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() |
| 7490 ** is not a permanent error and does not affect the return value of |
| 7491 ** sqlite3_backup_finish(). |
| 7492 ** |
| 7493 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] |
| 7494 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> |
| 7495 ** |
| 7496 ** ^The sqlite3_backup_remaining() routine returns the number of pages still |
| 7497 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). |
| 7498 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages |
| 7499 ** in the source database at the conclusion of the most recent |
| 7500 ** sqlite3_backup_step(). |
| 7501 ** ^(The values returned by these functions are only updated by |
| 7502 ** sqlite3_backup_step(). If the source database is modified in a way that |
| 7503 ** changes the size of the source database or the number of pages remaining, |
| 7504 ** those changes are not reflected in the output of sqlite3_backup_pagecount() |
| 7505 ** and sqlite3_backup_remaining() until after the next |
| 7506 ** sqlite3_backup_step().)^ |
| 7507 ** |
| 7508 ** <b>Concurrent Usage of Database Handles</b> |
| 7509 ** |
| 7510 ** ^The source [database connection] may be used by the application for other |
| 7511 ** purposes while a backup operation is underway or being initialized. |
| 7512 ** ^If SQLite is compiled and configured to support threadsafe database |
| 7513 ** connections, then the source database connection may be used concurrently |
| 7514 ** from within other threads. |
| 7515 ** |
| 7516 ** However, the application must guarantee that the destination |
| 7517 ** [database connection] is not passed to any other API (by any thread) after |
| 7518 ** sqlite3_backup_init() is called and before the corresponding call to |
| 7519 ** sqlite3_backup_finish(). SQLite does not currently check to see |
| 7520 ** if the application incorrectly accesses the destination [database connection] |
| 7521 ** and so no error code is reported, but the operations may malfunction |
| 7522 ** nevertheless. Use of the destination database connection while a |
| 7523 ** backup is in progress might also also cause a mutex deadlock. |
| 7524 ** |
| 7525 ** If running in [shared cache mode], the application must |
| 7526 ** guarantee that the shared cache used by the destination database |
| 7527 ** is not accessed while the backup is running. In practice this means |
| 7528 ** that the application must guarantee that the disk file being |
| 7529 ** backed up to is not accessed by any connection within the process, |
| 7530 ** not just the specific connection that was passed to sqlite3_backup_init(). |
| 7531 ** |
| 7532 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple |
| 7533 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). |
| 7534 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() |
| 7535 ** APIs are not strictly speaking threadsafe. If they are invoked at the |
| 7536 ** same time as another thread is invoking sqlite3_backup_step() it is |
| 7537 ** possible that they return invalid values. |
| 7538 */ |
| 7539 sqlite3_backup *sqlite3_backup_init( |
| 7540 sqlite3 *pDest, /* Destination database handle */ |
| 7541 const char *zDestName, /* Destination database name */ |
| 7542 sqlite3 *pSource, /* Source database handle */ |
| 7543 const char *zSourceName /* Source database name */ |
| 7544 ); |
| 7545 int sqlite3_backup_step(sqlite3_backup *p, int nPage); |
| 7546 int sqlite3_backup_finish(sqlite3_backup *p); |
| 7547 int sqlite3_backup_remaining(sqlite3_backup *p); |
| 7548 int sqlite3_backup_pagecount(sqlite3_backup *p); |
| 7549 |
| 7550 /* |
| 7551 ** CAPI3REF: Unlock Notification |
| 7552 ** METHOD: sqlite3 |
| 7553 ** |
| 7554 ** ^When running in shared-cache mode, a database operation may fail with |
| 7555 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or |
| 7556 ** individual tables within the shared-cache cannot be obtained. See |
| 7557 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. |
| 7558 ** ^This API may be used to register a callback that SQLite will invoke |
| 7559 ** when the connection currently holding the required lock relinquishes it. |
| 7560 ** ^This API is only available if the library was compiled with the |
| 7561 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. |
| 7562 ** |
| 7563 ** See Also: [Using the SQLite Unlock Notification Feature]. |
| 7564 ** |
| 7565 ** ^Shared-cache locks are released when a database connection concludes |
| 7566 ** its current transaction, either by committing it or rolling it back. |
| 7567 ** |
| 7568 ** ^When a connection (known as the blocked connection) fails to obtain a |
| 7569 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the |
| 7570 ** identity of the database connection (the blocking connection) that |
| 7571 ** has locked the required resource is stored internally. ^After an |
| 7572 ** application receives an SQLITE_LOCKED error, it may call the |
| 7573 ** sqlite3_unlock_notify() method with the blocked connection handle as |
| 7574 ** the first argument to register for a callback that will be invoked |
| 7575 ** when the blocking connections current transaction is concluded. ^The |
| 7576 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] |
| 7577 ** call that concludes the blocking connections transaction. |
| 7578 ** |
| 7579 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, |
| 7580 ** there is a chance that the blocking connection will have already |
| 7581 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. |
| 7582 ** If this happens, then the specified callback is invoked immediately, |
| 7583 ** from within the call to sqlite3_unlock_notify().)^ |
| 7584 ** |
| 7585 ** ^If the blocked connection is attempting to obtain a write-lock on a |
| 7586 ** shared-cache table, and more than one other connection currently holds |
| 7587 ** a read-lock on the same table, then SQLite arbitrarily selects one of |
| 7588 ** the other connections to use as the blocking connection. |
| 7589 ** |
| 7590 ** ^(There may be at most one unlock-notify callback registered by a |
| 7591 ** blocked connection. If sqlite3_unlock_notify() is called when the |
| 7592 ** blocked connection already has a registered unlock-notify callback, |
| 7593 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is |
| 7594 ** called with a NULL pointer as its second argument, then any existing |
| 7595 ** unlock-notify callback is canceled. ^The blocked connections |
| 7596 ** unlock-notify callback may also be canceled by closing the blocked |
| 7597 ** connection using [sqlite3_close()]. |
| 7598 ** |
| 7599 ** The unlock-notify callback is not reentrant. If an application invokes |
| 7600 ** any sqlite3_xxx API functions from within an unlock-notify callback, a |
| 7601 ** crash or deadlock may be the result. |
| 7602 ** |
| 7603 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always |
| 7604 ** returns SQLITE_OK. |
| 7605 ** |
| 7606 ** <b>Callback Invocation Details</b> |
| 7607 ** |
| 7608 ** When an unlock-notify callback is registered, the application provides a |
| 7609 ** single void* pointer that is passed to the callback when it is invoked. |
| 7610 ** However, the signature of the callback function allows SQLite to pass |
| 7611 ** it an array of void* context pointers. The first argument passed to |
| 7612 ** an unlock-notify callback is a pointer to an array of void* pointers, |
| 7613 ** and the second is the number of entries in the array. |
| 7614 ** |
| 7615 ** When a blocking connections transaction is concluded, there may be |
| 7616 ** more than one blocked connection that has registered for an unlock-notify |
| 7617 ** callback. ^If two or more such blocked connections have specified the |
| 7618 ** same callback function, then instead of invoking the callback function |
| 7619 ** multiple times, it is invoked once with the set of void* context pointers |
| 7620 ** specified by the blocked connections bundled together into an array. |
| 7621 ** This gives the application an opportunity to prioritize any actions |
| 7622 ** related to the set of unblocked database connections. |
| 7623 ** |
| 7624 ** <b>Deadlock Detection</b> |
| 7625 ** |
| 7626 ** Assuming that after registering for an unlock-notify callback a |
| 7627 ** database waits for the callback to be issued before taking any further |
| 7628 ** action (a reasonable assumption), then using this API may cause the |
| 7629 ** application to deadlock. For example, if connection X is waiting for |
| 7630 ** connection Y's transaction to be concluded, and similarly connection |
| 7631 ** Y is waiting on connection X's transaction, then neither connection |
| 7632 ** will proceed and the system may remain deadlocked indefinitely. |
| 7633 ** |
| 7634 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock |
| 7635 ** detection. ^If a given call to sqlite3_unlock_notify() would put the |
| 7636 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no |
| 7637 ** unlock-notify callback is registered. The system is said to be in |
| 7638 ** a deadlocked state if connection A has registered for an unlock-notify |
| 7639 ** callback on the conclusion of connection B's transaction, and connection |
| 7640 ** B has itself registered for an unlock-notify callback when connection |
| 7641 ** A's transaction is concluded. ^Indirect deadlock is also detected, so |
| 7642 ** the system is also considered to be deadlocked if connection B has |
| 7643 ** registered for an unlock-notify callback on the conclusion of connection |
| 7644 ** C's transaction, where connection C is waiting on connection A. ^Any |
| 7645 ** number of levels of indirection are allowed. |
| 7646 ** |
| 7647 ** <b>The "DROP TABLE" Exception</b> |
| 7648 ** |
| 7649 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost |
| 7650 ** always appropriate to call sqlite3_unlock_notify(). There is however, |
| 7651 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, |
| 7652 ** SQLite checks if there are any currently executing SELECT statements |
| 7653 ** that belong to the same connection. If there are, SQLITE_LOCKED is |
| 7654 ** returned. In this case there is no "blocking connection", so invoking |
| 7655 ** sqlite3_unlock_notify() results in the unlock-notify callback being |
| 7656 ** invoked immediately. If the application then re-attempts the "DROP TABLE" |
| 7657 ** or "DROP INDEX" query, an infinite loop might be the result. |
| 7658 ** |
| 7659 ** One way around this problem is to check the extended error code returned |
| 7660 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the |
| 7661 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in |
| 7662 ** the special "DROP TABLE/INDEX" case, the extended error code is just |
| 7663 ** SQLITE_LOCKED.)^ |
| 7664 */ |
| 7665 int sqlite3_unlock_notify( |
| 7666 sqlite3 *pBlocked, /* Waiting connection */ |
| 7667 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ |
| 7668 void *pNotifyArg /* Argument to pass to xNotify */ |
| 7669 ); |
| 7670 |
| 7671 |
| 7672 /* |
| 7673 ** CAPI3REF: String Comparison |
| 7674 ** |
| 7675 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications |
| 7676 ** and extensions to compare the contents of two buffers containing UTF-8 |
| 7677 ** strings in a case-independent fashion, using the same definition of "case |
| 7678 ** independence" that SQLite uses internally when comparing identifiers. |
| 7679 */ |
| 7680 int sqlite3_stricmp(const char *, const char *); |
| 7681 int sqlite3_strnicmp(const char *, const char *, int); |
| 7682 |
| 7683 /* |
| 7684 ** CAPI3REF: String Globbing |
| 7685 * |
| 7686 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if |
| 7687 ** string X matches the [GLOB] pattern P. |
| 7688 ** ^The definition of [GLOB] pattern matching used in |
| 7689 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the |
| 7690 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function |
| 7691 ** is case sensitive. |
| 7692 ** |
| 7693 ** Note that this routine returns zero on a match and non-zero if the strings |
| 7694 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. |
| 7695 ** |
| 7696 ** See also: [sqlite3_strlike()]. |
| 7697 */ |
| 7698 int sqlite3_strglob(const char *zGlob, const char *zStr); |
| 7699 |
| 7700 /* |
| 7701 ** CAPI3REF: String LIKE Matching |
| 7702 * |
| 7703 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if |
| 7704 ** string X matches the [LIKE] pattern P with escape character E. |
| 7705 ** ^The definition of [LIKE] pattern matching used in |
| 7706 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" |
| 7707 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without |
| 7708 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. |
| 7709 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case |
| 7710 ** insensitive - equivalent upper and lower case ASCII characters match |
| 7711 ** one another. |
| 7712 ** |
| 7713 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though |
| 7714 ** only ASCII characters are case folded. |
| 7715 ** |
| 7716 ** Note that this routine returns zero on a match and non-zero if the strings |
| 7717 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. |
| 7718 ** |
| 7719 ** See also: [sqlite3_strglob()]. |
| 7720 */ |
| 7721 int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); |
| 7722 |
| 7723 /* |
| 7724 ** CAPI3REF: Error Logging Interface |
| 7725 ** |
| 7726 ** ^The [sqlite3_log()] interface writes a message into the [error log] |
| 7727 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. |
| 7728 ** ^If logging is enabled, the zFormat string and subsequent arguments are |
| 7729 ** used with [sqlite3_snprintf()] to generate the final output string. |
| 7730 ** |
| 7731 ** The sqlite3_log() interface is intended for use by extensions such as |
| 7732 ** virtual tables, collating functions, and SQL functions. While there is |
| 7733 ** nothing to prevent an application from calling sqlite3_log(), doing so |
| 7734 ** is considered bad form. |
| 7735 ** |
| 7736 ** The zFormat string must not be NULL. |
| 7737 ** |
| 7738 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine |
| 7739 ** will not use dynamically allocated memory. The log message is stored in |
| 7740 ** a fixed-length buffer on the stack. If the log message is longer than |
| 7741 ** a few hundred characters, it will be truncated to the length of the |
| 7742 ** buffer. |
| 7743 */ |
| 7744 void sqlite3_log(int iErrCode, const char *zFormat, ...); |
| 7745 |
| 7746 /* |
| 7747 ** CAPI3REF: Write-Ahead Log Commit Hook |
| 7748 ** METHOD: sqlite3 |
| 7749 ** |
| 7750 ** ^The [sqlite3_wal_hook()] function is used to register a callback that |
| 7751 ** is invoked each time data is committed to a database in wal mode. |
| 7752 ** |
| 7753 ** ^(The callback is invoked by SQLite after the commit has taken place and |
| 7754 ** the associated write-lock on the database released)^, so the implementation |
| 7755 ** may read, write or [checkpoint] the database as required. |
| 7756 ** |
| 7757 ** ^The first parameter passed to the callback function when it is invoked |
| 7758 ** is a copy of the third parameter passed to sqlite3_wal_hook() when |
| 7759 ** registering the callback. ^The second is a copy of the database handle. |
| 7760 ** ^The third parameter is the name of the database that was written to - |
| 7761 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter |
| 7762 ** is the number of pages currently in the write-ahead log file, |
| 7763 ** including those that were just committed. |
| 7764 ** |
| 7765 ** The callback function should normally return [SQLITE_OK]. ^If an error |
| 7766 ** code is returned, that error will propagate back up through the |
| 7767 ** SQLite code base to cause the statement that provoked the callback |
| 7768 ** to report an error, though the commit will have still occurred. If the |
| 7769 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value |
| 7770 ** that does not correspond to any valid SQLite error code, the results |
| 7771 ** are undefined. |
| 7772 ** |
| 7773 ** A single database handle may have at most a single write-ahead log callback |
| 7774 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any |
| 7775 ** previously registered write-ahead log callback. ^Note that the |
| 7776 ** [sqlite3_wal_autocheckpoint()] interface and the |
| 7777 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will |
| 7778 ** overwrite any prior [sqlite3_wal_hook()] settings. |
| 7779 */ |
| 7780 void *sqlite3_wal_hook( |
| 7781 sqlite3*, |
| 7782 int(*)(void *,sqlite3*,const char*,int), |
| 7783 void* |
| 7784 ); |
| 7785 |
| 7786 /* |
| 7787 ** CAPI3REF: Configure an auto-checkpoint |
| 7788 ** METHOD: sqlite3 |
| 7789 ** |
| 7790 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around |
| 7791 ** [sqlite3_wal_hook()] that causes any database on [database connection] D |
| 7792 ** to automatically [checkpoint] |
| 7793 ** after committing a transaction if there are N or |
| 7794 ** more frames in the [write-ahead log] file. ^Passing zero or |
| 7795 ** a negative value as the nFrame parameter disables automatic |
| 7796 ** checkpoints entirely. |
| 7797 ** |
| 7798 ** ^The callback registered by this function replaces any existing callback |
| 7799 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback |
| 7800 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism |
| 7801 ** configured by this function. |
| 7802 ** |
| 7803 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface |
| 7804 ** from SQL. |
| 7805 ** |
| 7806 ** ^Checkpoints initiated by this mechanism are |
| 7807 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. |
| 7808 ** |
| 7809 ** ^Every new [database connection] defaults to having the auto-checkpoint |
| 7810 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] |
| 7811 ** pages. The use of this interface |
| 7812 ** is only necessary if the default setting is found to be suboptimal |
| 7813 ** for a particular application. |
| 7814 */ |
| 7815 int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); |
| 7816 |
| 7817 /* |
| 7818 ** CAPI3REF: Checkpoint a database |
| 7819 ** METHOD: sqlite3 |
| 7820 ** |
| 7821 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to |
| 7822 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ |
| 7823 ** |
| 7824 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the |
| 7825 ** [write-ahead log] for database X on [database connection] D to be |
| 7826 ** transferred into the database file and for the write-ahead log to |
| 7827 ** be reset. See the [checkpointing] documentation for addition |
| 7828 ** information. |
| 7829 ** |
| 7830 ** This interface used to be the only way to cause a checkpoint to |
| 7831 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] |
| 7832 ** interface was added. This interface is retained for backwards |
| 7833 ** compatibility and as a convenience for applications that need to manually |
| 7834 ** start a callback but which do not need the full power (and corresponding |
| 7835 ** complication) of [sqlite3_wal_checkpoint_v2()]. |
| 7836 */ |
| 7837 int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); |
| 7838 |
| 7839 /* |
| 7840 ** CAPI3REF: Checkpoint a database |
| 7841 ** METHOD: sqlite3 |
| 7842 ** |
| 7843 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint |
| 7844 ** operation on database X of [database connection] D in mode M. Status |
| 7845 ** information is written back into integers pointed to by L and C.)^ |
| 7846 ** ^(The M parameter must be a valid [checkpoint mode]:)^ |
| 7847 ** |
| 7848 ** <dl> |
| 7849 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> |
| 7850 ** ^Checkpoint as many frames as possible without waiting for any database |
| 7851 ** readers or writers to finish, then sync the database file if all frames |
| 7852 ** in the log were checkpointed. ^The [busy-handler callback] |
| 7853 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. |
| 7854 ** ^On the other hand, passive mode might leave the checkpoint unfinished |
| 7855 ** if there are concurrent readers or writers. |
| 7856 ** |
| 7857 ** <dt>SQLITE_CHECKPOINT_FULL<dd> |
| 7858 ** ^This mode blocks (it invokes the |
| 7859 ** [sqlite3_busy_handler|busy-handler callback]) until there is no |
| 7860 ** database writer and all readers are reading from the most recent database |
| 7861 ** snapshot. ^It then checkpoints all frames in the log file and syncs the |
| 7862 ** database file. ^This mode blocks new database writers while it is pending, |
| 7863 ** but new database readers are allowed to continue unimpeded. |
| 7864 ** |
| 7865 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> |
| 7866 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition |
| 7867 ** that after checkpointing the log file it blocks (calls the |
| 7868 ** [busy-handler callback]) |
| 7869 ** until all readers are reading from the database file only. ^This ensures |
| 7870 ** that the next writer will restart the log file from the beginning. |
| 7871 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new |
| 7872 ** database writer attempts while it is pending, but does not impede readers. |
| 7873 ** |
| 7874 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> |
| 7875 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the |
| 7876 ** addition that it also truncates the log file to zero bytes just prior |
| 7877 ** to a successful return. |
| 7878 ** </dl> |
| 7879 ** |
| 7880 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in |
| 7881 ** the log file or to -1 if the checkpoint could not run because |
| 7882 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not |
| 7883 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the |
| 7884 ** log file (including any that were already checkpointed before the function |
| 7885 ** was called) or to -1 if the checkpoint could not run due to an error or |
| 7886 ** because the database is not in WAL mode. ^Note that upon successful |
| 7887 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been |
| 7888 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. |
| 7889 ** |
| 7890 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If |
| 7891 ** any other process is running a checkpoint operation at the same time, the |
| 7892 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a |
| 7893 ** busy-handler configured, it will not be invoked in this case. |
| 7894 ** |
| 7895 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the |
| 7896 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be |
| 7897 ** obtained immediately, and a busy-handler is configured, it is invoked and |
| 7898 ** the writer lock retried until either the busy-handler returns 0 or the lock |
| 7899 ** is successfully obtained. ^The busy-handler is also invoked while waiting for |
| 7900 ** database readers as described above. ^If the busy-handler returns 0 before |
| 7901 ** the writer lock is obtained or while waiting for database readers, the |
| 7902 ** checkpoint operation proceeds from that point in the same way as |
| 7903 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible |
| 7904 ** without blocking any further. ^SQLITE_BUSY is returned in this case. |
| 7905 ** |
| 7906 ** ^If parameter zDb is NULL or points to a zero length string, then the |
| 7907 ** specified operation is attempted on all WAL databases [attached] to |
| 7908 ** [database connection] db. In this case the |
| 7909 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If |
| 7910 ** an SQLITE_BUSY error is encountered when processing one or more of the |
| 7911 ** attached WAL databases, the operation is still attempted on any remaining |
| 7912 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other |
| 7913 ** error occurs while processing an attached database, processing is abandoned |
| 7914 ** and the error code is returned to the caller immediately. ^If no error |
| 7915 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached |
| 7916 ** databases, SQLITE_OK is returned. |
| 7917 ** |
| 7918 ** ^If database zDb is the name of an attached database that is not in WAL |
| 7919 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If |
| 7920 ** zDb is not NULL (or a zero length string) and is not the name of any |
| 7921 ** attached database, SQLITE_ERROR is returned to the caller. |
| 7922 ** |
| 7923 ** ^Unless it returns SQLITE_MISUSE, |
| 7924 ** the sqlite3_wal_checkpoint_v2() interface |
| 7925 ** sets the error information that is queried by |
| 7926 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. |
| 7927 ** |
| 7928 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface |
| 7929 ** from SQL. |
| 7930 */ |
| 7931 int sqlite3_wal_checkpoint_v2( |
| 7932 sqlite3 *db, /* Database handle */ |
| 7933 const char *zDb, /* Name of attached database (or NULL) */ |
| 7934 int eMode, /* SQLITE_CHECKPOINT_* value */ |
| 7935 int *pnLog, /* OUT: Size of WAL log in frames */ |
| 7936 int *pnCkpt /* OUT: Total number of frames checkpointed */ |
| 7937 ); |
| 7938 |
| 7939 /* |
| 7940 ** CAPI3REF: Checkpoint Mode Values |
| 7941 ** KEYWORDS: {checkpoint mode} |
| 7942 ** |
| 7943 ** These constants define all valid values for the "checkpoint mode" passed |
| 7944 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. |
| 7945 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the |
| 7946 ** meaning of each of these checkpoint modes. |
| 7947 */ |
| 7948 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ |
| 7949 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ |
| 7950 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ |
| 7951 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ |
| 7952 |
| 7953 /* |
| 7954 ** CAPI3REF: Virtual Table Interface Configuration |
| 7955 ** |
| 7956 ** This function may be called by either the [xConnect] or [xCreate] method |
| 7957 ** of a [virtual table] implementation to configure |
| 7958 ** various facets of the virtual table interface. |
| 7959 ** |
| 7960 ** If this interface is invoked outside the context of an xConnect or |
| 7961 ** xCreate virtual table method then the behavior is undefined. |
| 7962 ** |
| 7963 ** At present, there is only one option that may be configured using |
| 7964 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options |
| 7965 ** may be added in the future. |
| 7966 */ |
| 7967 int sqlite3_vtab_config(sqlite3*, int op, ...); |
| 7968 |
| 7969 /* |
| 7970 ** CAPI3REF: Virtual Table Configuration Options |
| 7971 ** |
| 7972 ** These macros define the various options to the |
| 7973 ** [sqlite3_vtab_config()] interface that [virtual table] implementations |
| 7974 ** can use to customize and optimize their behavior. |
| 7975 ** |
| 7976 ** <dl> |
| 7977 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT |
| 7978 ** <dd>Calls of the form |
| 7979 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, |
| 7980 ** where X is an integer. If X is zero, then the [virtual table] whose |
| 7981 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not |
| 7982 ** support constraints. In this configuration (which is the default) if |
| 7983 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire |
| 7984 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been |
| 7985 ** specified as part of the users SQL statement, regardless of the actual |
| 7986 ** ON CONFLICT mode specified. |
| 7987 ** |
| 7988 ** If X is non-zero, then the virtual table implementation guarantees |
| 7989 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before |
| 7990 ** any modifications to internal or persistent data structures have been made. |
| 7991 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite |
| 7992 ** is able to roll back a statement or database transaction, and abandon |
| 7993 ** or continue processing the current SQL statement as appropriate. |
| 7994 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns |
| 7995 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode |
| 7996 ** had been ABORT. |
| 7997 ** |
| 7998 ** Virtual table implementations that are required to handle OR REPLACE |
| 7999 ** must do so within the [xUpdate] method. If a call to the |
| 8000 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON |
| 8001 ** CONFLICT policy is REPLACE, the virtual table implementation should |
| 8002 ** silently replace the appropriate rows within the xUpdate callback and |
| 8003 ** return SQLITE_OK. Or, if this is not possible, it may return |
| 8004 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT |
| 8005 ** constraint handling. |
| 8006 ** </dl> |
| 8007 */ |
| 8008 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 |
| 8009 |
| 8010 /* |
| 8011 ** CAPI3REF: Determine The Virtual Table Conflict Policy |
| 8012 ** |
| 8013 ** This function may only be called from within a call to the [xUpdate] method |
| 8014 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The |
| 8015 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], |
| 8016 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode |
| 8017 ** of the SQL statement that triggered the call to the [xUpdate] method of the |
| 8018 ** [virtual table]. |
| 8019 */ |
| 8020 int sqlite3_vtab_on_conflict(sqlite3 *); |
| 8021 |
| 8022 /* |
| 8023 ** CAPI3REF: Conflict resolution modes |
| 8024 ** KEYWORDS: {conflict resolution mode} |
| 8025 ** |
| 8026 ** These constants are returned by [sqlite3_vtab_on_conflict()] to |
| 8027 ** inform a [virtual table] implementation what the [ON CONFLICT] mode |
| 8028 ** is for the SQL statement being evaluated. |
| 8029 ** |
| 8030 ** Note that the [SQLITE_IGNORE] constant is also used as a potential |
| 8031 ** return value from the [sqlite3_set_authorizer()] callback and that |
| 8032 ** [SQLITE_ABORT] is also a [result code]. |
| 8033 */ |
| 8034 #define SQLITE_ROLLBACK 1 |
| 8035 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ |
| 8036 #define SQLITE_FAIL 3 |
| 8037 /* #define SQLITE_ABORT 4 // Also an error code */ |
| 8038 #define SQLITE_REPLACE 5 |
| 8039 |
| 8040 /* |
| 8041 ** CAPI3REF: Prepared Statement Scan Status Opcodes |
| 8042 ** KEYWORDS: {scanstatus options} |
| 8043 ** |
| 8044 ** The following constants can be used for the T parameter to the |
| 8045 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a |
| 8046 ** different metric for sqlite3_stmt_scanstatus() to return. |
| 8047 ** |
| 8048 ** When the value returned to V is a string, space to hold that string is |
| 8049 ** managed by the prepared statement S and will be automatically freed when |
| 8050 ** S is finalized. |
| 8051 ** |
| 8052 ** <dl> |
| 8053 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> |
| 8054 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be |
| 8055 ** set to the total number of times that the X-th loop has run.</dd> |
| 8056 ** |
| 8057 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> |
| 8058 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set |
| 8059 ** to the total number of rows examined by all iterations of the X-th loop.</dd> |
| 8060 ** |
| 8061 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> |
| 8062 ** <dd>^The "double" variable pointed to by the T parameter will be set to the |
| 8063 ** query planner's estimate for the average number of rows output from each |
| 8064 ** iteration of the X-th loop. If the query planner's estimates was accurate, |
| 8065 ** then this value will approximate the quotient NVISIT/NLOOP and the |
| 8066 ** product of this value for all prior loops with the same SELECTID will |
| 8067 ** be the NLOOP value for the current loop. |
| 8068 ** |
| 8069 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> |
| 8070 ** <dd>^The "const char *" variable pointed to by the T parameter will be set |
| 8071 ** to a zero-terminated UTF-8 string containing the name of the index or table |
| 8072 ** used for the X-th loop. |
| 8073 ** |
| 8074 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> |
| 8075 ** <dd>^The "const char *" variable pointed to by the T parameter will be set |
| 8076 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] |
| 8077 ** description for the X-th loop. |
| 8078 ** |
| 8079 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> |
| 8080 ** <dd>^The "int" variable pointed to by the T parameter will be set to the |
| 8081 ** "select-id" for the X-th loop. The select-id identifies which query or |
| 8082 ** subquery the loop is part of. The main query has a select-id of zero. |
| 8083 ** The select-id is the same value as is output in the first column |
| 8084 ** of an [EXPLAIN QUERY PLAN] query. |
| 8085 ** </dl> |
| 8086 */ |
| 8087 #define SQLITE_SCANSTAT_NLOOP 0 |
| 8088 #define SQLITE_SCANSTAT_NVISIT 1 |
| 8089 #define SQLITE_SCANSTAT_EST 2 |
| 8090 #define SQLITE_SCANSTAT_NAME 3 |
| 8091 #define SQLITE_SCANSTAT_EXPLAIN 4 |
| 8092 #define SQLITE_SCANSTAT_SELECTID 5 |
| 8093 |
| 8094 /* |
| 8095 ** CAPI3REF: Prepared Statement Scan Status |
| 8096 ** METHOD: sqlite3_stmt |
| 8097 ** |
| 8098 ** This interface returns information about the predicted and measured |
| 8099 ** performance for pStmt. Advanced applications can use this |
| 8100 ** interface to compare the predicted and the measured performance and |
| 8101 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. |
| 8102 ** |
| 8103 ** Since this interface is expected to be rarely used, it is only |
| 8104 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] |
| 8105 ** compile-time option. |
| 8106 ** |
| 8107 ** The "iScanStatusOp" parameter determines which status information to return. |
| 8108 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior |
| 8109 ** of this interface is undefined. |
| 8110 ** ^The requested measurement is written into a variable pointed to by |
| 8111 ** the "pOut" parameter. |
| 8112 ** Parameter "idx" identifies the specific loop to retrieve statistics for. |
| 8113 ** Loops are numbered starting from zero. ^If idx is out of range - less than |
| 8114 ** zero or greater than or equal to the total number of loops used to implement |
| 8115 ** the statement - a non-zero value is returned and the variable that pOut |
| 8116 ** points to is unchanged. |
| 8117 ** |
| 8118 ** ^Statistics might not be available for all loops in all statements. ^In cases |
| 8119 ** where there exist loops with no available statistics, this function behaves |
| 8120 ** as if the loop did not exist - it returns non-zero and leave the variable |
| 8121 ** that pOut points to unchanged. |
| 8122 ** |
| 8123 ** See also: [sqlite3_stmt_scanstatus_reset()] |
| 8124 */ |
| 8125 int sqlite3_stmt_scanstatus( |
| 8126 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ |
| 8127 int idx, /* Index of loop to report on */ |
| 8128 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ |
| 8129 void *pOut /* Result written here */ |
| 8130 ); |
| 8131 |
| 8132 /* |
| 8133 ** CAPI3REF: Zero Scan-Status Counters |
| 8134 ** METHOD: sqlite3_stmt |
| 8135 ** |
| 8136 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. |
| 8137 ** |
| 8138 ** This API is only available if the library is built with pre-processor |
| 8139 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. |
| 8140 */ |
| 8141 void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); |
| 8142 |
| 8143 /* |
| 8144 ** CAPI3REF: Flush caches to disk mid-transaction |
| 8145 ** |
| 8146 ** ^If a write-transaction is open on [database connection] D when the |
| 8147 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty |
| 8148 ** pages in the pager-cache that are not currently in use are written out |
| 8149 ** to disk. A dirty page may be in use if a database cursor created by an |
| 8150 ** active SQL statement is reading from it, or if it is page 1 of a database |
| 8151 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] |
| 8152 ** interface flushes caches for all schemas - "main", "temp", and |
| 8153 ** any [attached] databases. |
| 8154 ** |
| 8155 ** ^If this function needs to obtain extra database locks before dirty pages |
| 8156 ** can be flushed to disk, it does so. ^If those locks cannot be obtained |
| 8157 ** immediately and there is a busy-handler callback configured, it is invoked |
| 8158 ** in the usual manner. ^If the required lock still cannot be obtained, then |
| 8159 ** the database is skipped and an attempt made to flush any dirty pages |
| 8160 ** belonging to the next (if any) database. ^If any databases are skipped |
| 8161 ** because locks cannot be obtained, but no other error occurs, this |
| 8162 ** function returns SQLITE_BUSY. |
| 8163 ** |
| 8164 ** ^If any other error occurs while flushing dirty pages to disk (for |
| 8165 ** example an IO error or out-of-memory condition), then processing is |
| 8166 ** abandoned and an SQLite [error code] is returned to the caller immediately. |
| 8167 ** |
| 8168 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. |
| 8169 ** |
| 8170 ** ^This function does not set the database handle error code or message |
| 8171 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. |
| 8172 */ |
| 8173 int sqlite3_db_cacheflush(sqlite3*); |
| 8174 |
| 8175 /* |
| 8176 ** CAPI3REF: The pre-update hook. |
| 8177 ** |
| 8178 ** ^These interfaces are only available if SQLite is compiled using the |
| 8179 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. |
| 8180 ** |
| 8181 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function |
| 8182 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation |
| 8183 ** on a database table. |
| 8184 ** ^At most one preupdate hook may be registered at a time on a single |
| 8185 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides |
| 8186 ** the previous setting. |
| 8187 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] |
| 8188 ** with a NULL pointer as the second parameter. |
| 8189 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as |
| 8190 ** the first parameter to callbacks. |
| 8191 ** |
| 8192 ** ^The preupdate hook only fires for changes to real database tables; the |
| 8193 ** preupdate hook is not invoked for changes to [virtual tables] or to |
| 8194 ** system tables like sqlite_master or sqlite_stat1. |
| 8195 ** |
| 8196 ** ^The second parameter to the preupdate callback is a pointer to |
| 8197 ** the [database connection] that registered the preupdate hook. |
| 8198 ** ^The third parameter to the preupdate callback is one of the constants |
| 8199 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the |
| 8200 ** kind of update operation that is about to occur. |
| 8201 ** ^(The fourth parameter to the preupdate callback is the name of the |
| 8202 ** database within the database connection that is being modified. This |
| 8203 ** will be "main" for the main database or "temp" for TEMP tables or |
| 8204 ** the name given after the AS keyword in the [ATTACH] statement for attached |
| 8205 ** databases.)^ |
| 8206 ** ^The fifth parameter to the preupdate callback is the name of the |
| 8207 ** table that is being modified. |
| 8208 ** |
| 8209 ** For an UPDATE or DELETE operation on a [rowid table], the sixth |
| 8210 ** parameter passed to the preupdate callback is the initial [rowid] of the |
| 8211 ** row being modified or deleted. For an INSERT operation on a rowid table, |
| 8212 ** or any operation on a WITHOUT ROWID table, the value of the sixth |
| 8213 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the |
| 8214 ** seventh parameter is the final rowid value of the row being inserted |
| 8215 ** or updated. The value of the seventh parameter passed to the callback |
| 8216 ** function is not defined for operations on WITHOUT ROWID tables, or for |
| 8217 ** INSERT operations on rowid tables. |
| 8218 ** |
| 8219 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], |
| 8220 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces |
| 8221 ** provide additional information about a preupdate event. These routines |
| 8222 ** may only be called from within a preupdate callback. Invoking any of |
| 8223 ** these routines from outside of a preupdate callback or with a |
| 8224 ** [database connection] pointer that is different from the one supplied |
| 8225 ** to the preupdate callback results in undefined and probably undesirable |
| 8226 ** behavior. |
| 8227 ** |
| 8228 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns |
| 8229 ** in the row that is being inserted, updated, or deleted. |
| 8230 ** |
| 8231 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to |
| 8232 ** a [protected sqlite3_value] that contains the value of the Nth column of |
| 8233 ** the table row before it is updated. The N parameter must be between 0 |
| 8234 ** and one less than the number of columns or the behavior will be |
| 8235 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE |
| 8236 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the |
| 8237 ** behavior is undefined. The [sqlite3_value] that P points to |
| 8238 ** will be destroyed when the preupdate callback returns. |
| 8239 ** |
| 8240 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to |
| 8241 ** a [protected sqlite3_value] that contains the value of the Nth column of |
| 8242 ** the table row after it is updated. The N parameter must be between 0 |
| 8243 ** and one less than the number of columns or the behavior will be |
| 8244 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE |
| 8245 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the |
| 8246 ** behavior is undefined. The [sqlite3_value] that P points to |
| 8247 ** will be destroyed when the preupdate callback returns. |
| 8248 ** |
| 8249 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate |
| 8250 ** callback was invoked as a result of a direct insert, update, or delete |
| 8251 ** operation; or 1 for inserts, updates, or deletes invoked by top-level |
| 8252 ** triggers; or 2 for changes resulting from triggers called by top-level |
| 8253 ** triggers; and so forth. |
| 8254 ** |
| 8255 ** See also: [sqlite3_update_hook()] |
| 8256 */ |
| 8257 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) |
| 8258 void *sqlite3_preupdate_hook( |
| 8259 sqlite3 *db, |
| 8260 void(*xPreUpdate)( |
| 8261 void *pCtx, /* Copy of third arg to preupdate_hook() */ |
| 8262 sqlite3 *db, /* Database handle */ |
| 8263 int op, /* SQLITE_UPDATE, DELETE or INSERT */ |
| 8264 char const *zDb, /* Database name */ |
| 8265 char const *zName, /* Table name */ |
| 8266 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ |
| 8267 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ |
| 8268 ), |
| 8269 void* |
| 8270 ); |
| 8271 int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); |
| 8272 int sqlite3_preupdate_count(sqlite3 *); |
| 8273 int sqlite3_preupdate_depth(sqlite3 *); |
| 8274 int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); |
| 8275 #endif |
| 8276 |
| 8277 /* |
| 8278 ** CAPI3REF: Low-level system error code |
| 8279 ** |
| 8280 ** ^Attempt to return the underlying operating system error code or error |
| 8281 ** number that caused the most recent I/O error or failure to open a file. |
| 8282 ** The return value is OS-dependent. For example, on unix systems, after |
| 8283 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be |
| 8284 ** called to get back the underlying "errno" that caused the problem, such |
| 8285 ** as ENOSPC, EAUTH, EISDIR, and so forth. |
| 8286 */ |
| 8287 int sqlite3_system_errno(sqlite3*); |
| 8288 |
| 8289 /* |
| 8290 ** CAPI3REF: Database Snapshot |
| 8291 ** KEYWORDS: {snapshot} {sqlite3_snapshot} |
| 8292 ** EXPERIMENTAL |
| 8293 ** |
| 8294 ** An instance of the snapshot object records the state of a [WAL mode] |
| 8295 ** database for some specific point in history. |
| 8296 ** |
| 8297 ** In [WAL mode], multiple [database connections] that are open on the |
| 8298 ** same database file can each be reading a different historical version |
| 8299 ** of the database file. When a [database connection] begins a read |
| 8300 ** transaction, that connection sees an unchanging copy of the database |
| 8301 ** as it existed for the point in time when the transaction first started. |
| 8302 ** Subsequent changes to the database from other connections are not seen |
| 8303 ** by the reader until a new read transaction is started. |
| 8304 ** |
| 8305 ** The sqlite3_snapshot object records state information about an historical |
| 8306 ** version of the database file so that it is possible to later open a new read |
| 8307 ** transaction that sees that historical version of the database rather than |
| 8308 ** the most recent version. |
| 8309 ** |
| 8310 ** The constructor for this object is [sqlite3_snapshot_get()]. The |
| 8311 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer |
| 8312 ** to an historical snapshot (if possible). The destructor for |
| 8313 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. |
| 8314 */ |
| 8315 typedef struct sqlite3_snapshot { |
| 8316 unsigned char hidden[48]; |
| 8317 } sqlite3_snapshot; |
| 8318 |
| 8319 /* |
| 8320 ** CAPI3REF: Record A Database Snapshot |
| 8321 ** EXPERIMENTAL |
| 8322 ** |
| 8323 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a |
| 8324 ** new [sqlite3_snapshot] object that records the current state of |
| 8325 ** schema S in database connection D. ^On success, the |
| 8326 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly |
| 8327 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. |
| 8328 ** If there is not already a read-transaction open on schema S when |
| 8329 ** this function is called, one is opened automatically. |
| 8330 ** |
| 8331 ** The following must be true for this function to succeed. If any of |
| 8332 ** the following statements are false when sqlite3_snapshot_get() is |
| 8333 ** called, SQLITE_ERROR is returned. The final value of *P is undefined |
| 8334 ** in this case. |
| 8335 ** |
| 8336 ** <ul> |
| 8337 ** <li> The database handle must be in [autocommit mode]. |
| 8338 ** |
| 8339 ** <li> Schema S of [database connection] D must be a [WAL mode] database. |
| 8340 ** |
| 8341 ** <li> There must not be a write transaction open on schema S of database |
| 8342 ** connection D. |
| 8343 ** |
| 8344 ** <li> One or more transactions must have been written to the current wal |
| 8345 ** file since it was created on disk (by any connection). This means |
| 8346 ** that a snapshot cannot be taken on a wal mode database with no wal |
| 8347 ** file immediately after it is first opened. At least one transaction |
| 8348 ** must be written to it first. |
| 8349 ** </ul> |
| 8350 ** |
| 8351 ** This function may also return SQLITE_NOMEM. If it is called with the |
| 8352 ** database handle in autocommit mode but fails for some other reason, |
| 8353 ** whether or not a read transaction is opened on schema S is undefined. |
| 8354 ** |
| 8355 ** The [sqlite3_snapshot] object returned from a successful call to |
| 8356 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] |
| 8357 ** to avoid a memory leak. |
| 8358 ** |
| 8359 ** The [sqlite3_snapshot_get()] interface is only available when the |
| 8360 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. |
| 8361 */ |
| 8362 SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( |
| 8363 sqlite3 *db, |
| 8364 const char *zSchema, |
| 8365 sqlite3_snapshot **ppSnapshot |
| 8366 ); |
| 8367 |
| 8368 /* |
| 8369 ** CAPI3REF: Start a read transaction on an historical snapshot |
| 8370 ** EXPERIMENTAL |
| 8371 ** |
| 8372 ** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a |
| 8373 ** read transaction for schema S of |
| 8374 ** [database connection] D such that the read transaction |
| 8375 ** refers to historical [snapshot] P, rather than the most |
| 8376 ** recent change to the database. |
| 8377 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success |
| 8378 ** or an appropriate [error code] if it fails. |
| 8379 ** |
| 8380 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be |
| 8381 ** the first operation following the [BEGIN] that takes the schema S |
| 8382 ** out of [autocommit mode]. |
| 8383 ** ^In other words, schema S must not currently be in |
| 8384 ** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the |
| 8385 ** database connection D must be out of [autocommit mode]. |
| 8386 ** ^A [snapshot] will fail to open if it has been overwritten by a |
| 8387 ** [checkpoint]. |
| 8388 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the |
| 8389 ** database connection D does not know that the database file for |
| 8390 ** schema S is in [WAL mode]. A database connection might not know |
| 8391 ** that the database file is in [WAL mode] if there has been no prior |
| 8392 ** I/O on that database connection, or if the database entered [WAL mode] |
| 8393 ** after the most recent I/O on the database connection.)^ |
| 8394 ** (Hint: Run "[PRAGMA application_id]" against a newly opened |
| 8395 ** database connection in order to make it ready to use snapshots.) |
| 8396 ** |
| 8397 ** The [sqlite3_snapshot_open()] interface is only available when the |
| 8398 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. |
| 8399 */ |
| 8400 SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( |
| 8401 sqlite3 *db, |
| 8402 const char *zSchema, |
| 8403 sqlite3_snapshot *pSnapshot |
| 8404 ); |
| 8405 |
| 8406 /* |
| 8407 ** CAPI3REF: Destroy a snapshot |
| 8408 ** EXPERIMENTAL |
| 8409 ** |
| 8410 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. |
| 8411 ** The application must eventually free every [sqlite3_snapshot] object |
| 8412 ** using this routine to avoid a memory leak. |
| 8413 ** |
| 8414 ** The [sqlite3_snapshot_free()] interface is only available when the |
| 8415 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. |
| 8416 */ |
| 8417 SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); |
| 8418 |
| 8419 /* |
| 8420 ** CAPI3REF: Compare the ages of two snapshot handles. |
| 8421 ** EXPERIMENTAL |
| 8422 ** |
| 8423 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages |
| 8424 ** of two valid snapshot handles. |
| 8425 ** |
| 8426 ** If the two snapshot handles are not associated with the same database |
| 8427 ** file, the result of the comparison is undefined. |
| 8428 ** |
| 8429 ** Additionally, the result of the comparison is only valid if both of the |
| 8430 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the |
| 8431 ** last time the wal file was deleted. The wal file is deleted when the |
| 8432 ** database is changed back to rollback mode or when the number of database |
| 8433 ** clients drops to zero. If either snapshot handle was obtained before the |
| 8434 ** wal file was last deleted, the value returned by this function |
| 8435 ** is undefined. |
| 8436 ** |
| 8437 ** Otherwise, this API returns a negative value if P1 refers to an older |
| 8438 ** snapshot than P2, zero if the two handles refer to the same database |
| 8439 ** snapshot, and a positive value if P1 is a newer snapshot than P2. |
| 8440 */ |
| 8441 SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( |
| 8442 sqlite3_snapshot *p1, |
| 8443 sqlite3_snapshot *p2 |
| 8444 ); |
| 8445 |
| 8446 /* |
| 8447 ** CAPI3REF: Recover snapshots from a wal file |
| 8448 ** EXPERIMENTAL |
| 8449 ** |
| 8450 ** If all connections disconnect from a database file but do not perform |
| 8451 ** a checkpoint, the existing wal file is opened along with the database |
| 8452 ** file the next time the database is opened. At this point it is only |
| 8453 ** possible to successfully call sqlite3_snapshot_open() to open the most |
| 8454 ** recent snapshot of the database (the one at the head of the wal file), |
| 8455 ** even though the wal file may contain other valid snapshots for which |
| 8456 ** clients have sqlite3_snapshot handles. |
| 8457 ** |
| 8458 ** This function attempts to scan the wal file associated with database zDb |
| 8459 ** of database handle db and make all valid snapshots available to |
| 8460 ** sqlite3_snapshot_open(). It is an error if there is already a read |
| 8461 ** transaction open on the database, or if the database is not a wal mode |
| 8462 ** database. |
| 8463 ** |
| 8464 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. |
| 8465 */ |
| 8466 SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); |
| 8467 |
| 8468 /* |
| 8469 ** Undo the hack that converts floating point types to integer for |
| 8470 ** builds on processors without floating point support. |
| 8471 */ |
| 8472 #ifdef SQLITE_OMIT_FLOATING_POINT |
| 8473 # undef double |
| 8474 #endif |
| 8475 |
| 8476 #ifdef __cplusplus |
| 8477 } /* End of the 'extern "C"' block */ |
| 8478 #endif |
| 8479 #endif /* SQLITE3_H */ |
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