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Overview
Comment: | Enhance the memvfs extension so that it can be read/write. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
04c9197d589666299aef86ee6a56df63 |
User & Date: | drh 2018-01-02 16:02:50.552 |
Context
2018-01-02
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18:11 | In the constraint resolution logic, be careful not to cache column values in registers whose initialization might be bypassed by an OP_NoConflict opcode. Fix for ticket [dc3f932f5a147771] reported by OSSFuzz. (check-in: 2846458af5 user: drh tags: trunk) | |
16:02 | Enhance the memvfs extension so that it can be read/write. (check-in: 04c9197d58 user: drh tags: trunk) | |
13:48 | Updates to the sqlite3_file_control() documentation. No changes to code. (check-in: 240e32ab1f user: drh tags: trunk) | |
Changes
Changes to ext/misc/memvfs.c.
1 2 3 4 5 6 7 8 9 10 11 12 | /* ** 2016-09-07 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ****************************************************************************** ** | | < | | < > | | > > > > > > > > > > > > | | < | | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | /* ** 2016-09-07 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ****************************************************************************** ** ** This is an in-memory VFS implementation. The application supplies ** a chunk of memory to hold the database file. ** ** Because there is place to store a rollback or wal journal, the database ** must use one of journal_mode=MEMORY or journal_mode=NONE. ** ** USAGE: ** ** sqlite3_open_v2("file:/whatever?ptr=0xf05538&sz=14336&max=65536", &db, ** SQLITE_OPEN_READWRITE | SQLITE_OPEN_URI, ** "memvfs"); ** ** These are the query parameters: ** ** ptr= The address of the memory buffer that holds the database. ** ** sz= The current size the database file ** ** maxsz= The maximum size of the database. In other words, the ** amount of space allocated for the ptr= buffer. ** ** freeonclose= If true, then sqlite3_free() is called on the ptr= ** value when the connection closes. ** ** The ptr= and sz= query parameters are required. If maxsz= is omitted, ** then it defaults to the sz= value. Parameter values can be in either ** decimal or hexadecimal. The filename in the URI is ignored. */ #include <sqlite3ext.h> SQLITE_EXTENSION_INIT1 #include <string.h> #include <assert.h> |
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45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 | */ #define ORIGVFS(p) ((sqlite3_vfs*)((p)->pAppData)) /* An open file */ struct MemFile { sqlite3_file base; /* IO methods */ sqlite3_int64 sz; /* Size of the file */ unsigned char *aData; /* content of the file */ }; /* ** Methods for MemFile */ static int memClose(sqlite3_file*); static int memRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); | > > | 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 | */ #define ORIGVFS(p) ((sqlite3_vfs*)((p)->pAppData)) /* An open file */ struct MemFile { sqlite3_file base; /* IO methods */ sqlite3_int64 sz; /* Size of the file */ sqlite3_int64 szMax; /* Space allocated to aData */ unsigned char *aData; /* content of the file */ int bFreeOnClose; /* Invoke sqlite3_free() on aData at close */ }; /* ** Methods for MemFile */ static int memClose(sqlite3_file*); static int memRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); |
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140 141 142 143 144 145 146 147 148 149 150 151 152 153 | /* ** Close an mem-file. ** ** The pData pointer is owned by the application, so there is nothing ** to free. */ static int memClose(sqlite3_file *pFile){ return SQLITE_OK; } /* ** Read data from an mem-file. */ static int memRead( | > > | 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 | /* ** Close an mem-file. ** ** The pData pointer is owned by the application, so there is nothing ** to free. */ static int memClose(sqlite3_file *pFile){ MemFile *p = (MemFile *)pFile; if( p->bFreeOnClose ) sqlite3_free(p->aData); return SQLITE_OK; } /* ** Read data from an mem-file. */ static int memRead( |
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166 167 168 169 170 171 172 | */ static int memWrite( sqlite3_file *pFile, const void *z, int iAmt, sqlite_int64 iOfst ){ | > > > > > > > | > > > > > > | | | | 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 | */ static int memWrite( sqlite3_file *pFile, const void *z, int iAmt, sqlite_int64 iOfst ){ MemFile *p = (MemFile *)pFile; if( iOfst+iAmt>p->sz ){ if( iOfst+iAmt>p->szMax ) return SQLITE_FULL; if( iOfst>p->sz ) memset(p->aData+p->sz, 0, iOfst-p->sz); p->sz = iOfst+iAmt; } memcpy(p->aData+iOfst, z, iAmt); return SQLITE_OK; } /* ** Truncate an mem-file. */ static int memTruncate(sqlite3_file *pFile, sqlite_int64 size){ MemFile *p = (MemFile *)pFile; if( size>p->sz ){ if( size>p->szMax ) return SQLITE_FULL; memset(p->aData+p->sz, 0, size-p->sz); } p->sz = size; return SQLITE_OK; } /* ** Sync an mem-file. */ static int memSync(sqlite3_file *pFile, int flags){ return SQLITE_OK; } /* ** Return the current file-size of an mem-file. */ static int memFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){ MemFile *p = (MemFile *)pFile; *pSize = p->sz; return SQLITE_OK; } /* ** Lock an mem-file. */ static int memLock(sqlite3_file *pFile, int eLock){ return SQLITE_OK; } /* ** Unlock an mem-file. */ static int memUnlock(sqlite3_file *pFile, int eLock){ return SQLITE_OK; |
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238 239 240 241 242 243 244 | return 1024; } /* ** Return the device characteristic flags supported by an mem-file. */ static int memDeviceCharacteristics(sqlite3_file *pFile){ | | > > > | | | 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 | return 1024; } /* ** Return the device characteristic flags supported by an mem-file. */ static int memDeviceCharacteristics(sqlite3_file *pFile){ return SQLITE_IOCAP_ATOMIC | SQLITE_IOCAP_POWERSAFE_OVERWRITE | SQLITE_IOCAP_SAFE_APPEND | SQLITE_IOCAP_SEQUENTIAL; } /* Create a shared memory file mapping */ static int memShmMap( sqlite3_file *pFile, int iPg, int pgsz, int bExtend, void volatile **pp ){ return SQLITE_IOERR_SHMMAP; } /* Perform locking on a shared-memory segment */ static int memShmLock(sqlite3_file *pFile, int offset, int n, int flags){ return SQLITE_IOERR_SHMLOCK; } /* Memory barrier operation on shared memory */ static void memShmBarrier(sqlite3_file *pFile){ return; } |
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301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 | MemFile *p = (MemFile*)pFile; memset(p, 0, sizeof(*p)); if( (flags & SQLITE_OPEN_MAIN_DB)==0 ) return SQLITE_CANTOPEN; p->aData = (unsigned char*)sqlite3_uri_int64(zName,"ptr",0); if( p->aData==0 ) return SQLITE_CANTOPEN; p->sz = sqlite3_uri_int64(zName,"sz",0); if( p->sz<0 ) return SQLITE_CANTOPEN; pFile->pMethods = &mem_io_methods; return SQLITE_OK; } /* ** Delete the file located at zPath. If the dirSync argument is true, ** ensure the file-system modifications are synced to disk before ** returning. */ static int memDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){ | > > > | < < < < | < < < | 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 | MemFile *p = (MemFile*)pFile; memset(p, 0, sizeof(*p)); if( (flags & SQLITE_OPEN_MAIN_DB)==0 ) return SQLITE_CANTOPEN; p->aData = (unsigned char*)sqlite3_uri_int64(zName,"ptr",0); if( p->aData==0 ) return SQLITE_CANTOPEN; p->sz = sqlite3_uri_int64(zName,"sz",0); if( p->sz<0 ) return SQLITE_CANTOPEN; p->szMax = sqlite3_uri_int64(zName,"max",p->sz); if( p->szMax<p->sz ) return SQLITE_CANTOPEN; p->bFreeOnClose = sqlite3_uri_boolean(zName,"freeonclose",0); pFile->pMethods = &mem_io_methods; return SQLITE_OK; } /* ** Delete the file located at zPath. If the dirSync argument is true, ** ensure the file-system modifications are synced to disk before ** returning. */ static int memDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){ return SQLITE_IOERR_DELETE; } /* ** Test for access permissions. Return true if the requested permission ** is available, or false otherwise. */ static int memAccess( sqlite3_vfs *pVfs, const char *zPath, int flags, int *pResOut ){ *pResOut = 0; return SQLITE_OK; } /* ** Populate buffer zOut with the full canonical pathname corresponding ** to the pathname in zPath. zOut is guaranteed to point to a buffer ** of at least (INST_MAX_PATHNAME+1) bytes. |
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412 413 414 415 416 417 418 | } static int memCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){ return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p); } #ifdef MEMVFS_TEST /* | | | > > > > > > > | > | | > > > > | > | | | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | > > > > | | > | 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 | } static int memCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){ return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p); } #ifdef MEMVFS_TEST /* ** memvfs_from_file(FILENAME, MAXSIZE) ** ** This an SQL function used to help in testing the memvfs VFS. The ** function reads the content of a file into memory and then returns ** a URI that can be handed to ATTACH to attach the memory buffer as ** a database. Example: ** ** ATTACH memvfs_from_file('test.db',1048576) AS inmem; ** ** The optional MAXSIZE argument gives the size of the memory allocation ** used to hold the database. If omitted, it defaults to the size of the ** file on disk. */ #include <stdio.h> static void memvfsFromFileFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ unsigned char *p; sqlite3_int64 sz; sqlite3_int64 szMax; FILE *in; const char *zFilename = (const char*)sqlite3_value_text(argv[0]); char *zUri; if( zFilename==0 ) return; in = fopen(zFilename, "rb"); if( in==0 ) return; fseek(in, 0, SEEK_END); szMax = sz = ftell(in); rewind(in); if( argc>=2 ){ szMax = sqlite3_value_int64(argv[1]); if( szMax<sz ) szMax = sz; } p = sqlite3_malloc64( szMax ); if( p==0 ){ fclose(in); sqlite3_result_error_nomem(context); return; } fread(p, sz, 1, in); fclose(in); zUri = sqlite3_mprintf( "file:/mem?vfs=memvfs&ptr=%lld&sz=%lld&max=%lld&freeonclose=1", (sqlite3_int64)p, sz, szMax); sqlite3_result_text(context, zUri, -1, sqlite3_free); } #endif /* MEMVFS_TEST */ #ifdef MEMVFS_TEST /* ** memvfs_to_file(SCHEMA, FILENAME) ** ** The schema identified by SCHEMA must be a memvfs database. Write ** the content of this database into FILENAME. */ static void memvfsToFileFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ MemFile *p = 0; FILE *out; int rc; sqlite3 *db = sqlite3_context_db_handle(context); sqlite3_vfs *pVfs = 0; const char *zSchema = (const char*)sqlite3_value_text(argv[0]); const char *zFilename = (const char*)sqlite3_value_text(argv[1]); if( zFilename==0 ) return; out = fopen(zFilename, "wb"); if( out==0 ) return; rc = sqlite3_file_control(db, zSchema, SQLITE_FCNTL_VFS_POINTER, &pVfs); if( rc || pVfs==0 ) return; if( strcmp(pVfs->zName,"memvfs")!=0 ) return; rc = sqlite3_file_control(db, zSchema, SQLITE_FCNTL_FILE_POINTER, &p); if( rc ) return; fwrite(p->aData, 1, (size_t)p->sz, out); fclose(out); } #endif /* MEMVFS_TEST */ #ifdef MEMVFS_TEST /* Called for each new database connection */ static int memvfsRegister( sqlite3 *db, char **pzErrMsg, const struct sqlite3_api_routines *pThunk ){ sqlite3_create_function(db, "memvfs_from_file", 1, SQLITE_UTF8, 0, memvfsFromFileFunc, 0, 0); sqlite3_create_function(db, "memvfs_from_file", 2, SQLITE_UTF8, 0, memvfsFromFileFunc, 0, 0); sqlite3_create_function(db, "memvfs_to_file", 2, SQLITE_UTF8, 0, memvfsToFileFunc, 0, 0); return SQLITE_OK; } #endif /* MEMVFS_TEST */ #ifdef _WIN32 __declspec(dllexport) #endif |
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481 482 483 484 485 486 487 488 489 490 491 | mem_vfs.pAppData = sqlite3_vfs_find(0); mem_vfs.szOsFile = sizeof(MemFile); rc = sqlite3_vfs_register(&mem_vfs, 1); #ifdef MEMVFS_TEST if( rc==SQLITE_OK ){ rc = sqlite3_auto_extension((void(*)(void))memvfsRegister); } #endif if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY; return rc; } | > > > | 561 562 563 564 565 566 567 568 569 570 571 572 573 574 | mem_vfs.pAppData = sqlite3_vfs_find(0); mem_vfs.szOsFile = sizeof(MemFile); rc = sqlite3_vfs_register(&mem_vfs, 1); #ifdef MEMVFS_TEST if( rc==SQLITE_OK ){ rc = sqlite3_auto_extension((void(*)(void))memvfsRegister); } if( rc==SQLITE_OK ){ rc = memvfsRegister(db, pzErrMsg, pApi); } #endif if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY; return rc; } |