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Overview
Comment: | Further updates to comments in pager.c. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | experimental |
Files: | files | file ages | folders |
SHA1: |
5f4c17a33fd442d66c1bf75af9b21954 |
User & Date: | dan 2010-08-06 12:00:27.000 |
Context
2010-08-06
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13:53 | Merge trunk changes into experimental branch. (check-in: aef6698c73 user: dan tags: experimental) | |
12:00 | Further updates to comments in pager.c. (check-in: 5f4c17a33f user: dan tags: experimental) | |
09:43 | Modify test_journal.c to work with pre-allocated databases. (check-in: 4894a5d210 user: dan tags: experimental) | |
Changes
Changes to src/pager.c.
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126 127 128 129 130 131 132 | #define FILEHANDLEID(fd) ((int)fd) /* ** The Pager.eState variable stores the current 'state' of a pager. A ** pager may be in any one of the seven states shown in the following ** state diagram. ** | | | | | | | | | | | < < < < | | > > > > > > > > > > > > > > > > > > | 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 | #define FILEHANDLEID(fd) ((int)fd) /* ** The Pager.eState variable stores the current 'state' of a pager. A ** pager may be in any one of the seven states shown in the following ** state diagram. ** ** OPEN <------+------+ ** | | | ** V | | ** +---------> READER-------+ | ** | | | ** | V | ** |<-------WRITER_LOCKED------> ERROR ** | | ^ ** | V | ** |<------WRITER_CACHEMOD-------->| ** | | | ** | V | ** |<-------WRITER_DBMOD---------->| ** | | | ** | V | ** +<------WRITER_FINISHED-------->+ ** ** ** List of state transitions and the C [function] that performs each: ** ** OPEN -> READER [sqlite3PagerSharedLock] ** READER -> OPEN [pager_unlock] ** ** READER -> WRITER_LOCKED [sqlite3PagerBegin] ** WRITER_LOCKED -> WRITER_CACHEMOD [pager_open_journal] ** WRITER_CACHEMOD -> WRITER_DBMOD [syncJournal] ** WRITER_DBMOD -> WRITER_FINISHED [sqlite3PagerCommitPhaseOne] ** WRITER_*** -> READER [pager_end_transaction] ** ** WRITER_*** -> ERROR [pager_error] ** ERROR -> OPEN [pager_unlock] ** ** ** OPEN: ** ** The pager starts up in this state. Nothing is guaranteed in this ** state - the file may or may not be locked and the database size is ** unknown. The database may not be read or written. ** ** * No read or write transaction is active. ** * Any lock, or no lock at all, may be held on the database file. ** * The dbSize, dbOrigSize and dbFileSize variables may not be trusted. ** ** READER: ** ** In this state all the requirements for reading the database in ** rollback (non-WAL) mode are met. Unless the pager is (or recently ** was) in exclusive-locking mode, a user-level read transaction is ** open. The database size is known in this state. ** ** A connection running with locking_mode=normal enters this state when ** it opens a read-transaction on the database and returns to state ** OPEN after the read-transaction is completed. However a connection ** running in locking_mode=exclusive (including temp databases) remains in ** this state even after the read-transaction is closed. The only way ** a locking_mode=exclusive connection can transition from READER to OPEN ** is via the ERROR state (see below). ** ** * A read transaction may be active (but a write-transaction cannot). ** * A SHARED or greater lock is held on the database file. ** * The dbSize variable may be trusted (even if a user-level read ** transaction is not active). The dbOrigSize and dbFileSize variables ** may not be trusted at this point. ** * If the database is a WAL database, then the WAL connection is open. ** * Even if a read-transaction is not open, it is guaranteed that ** there is no hot-journal in the file-system. ** ** WRITER_LOCKED: ** ** The pager moves to this state from READER when a write-transaction ** is first opened on the database. In WRITER_LOCKED state, all locks ** required to start a write-transaction are held, but no actual ** modifications to the cache or database have taken place. ** ** In rollback mode, a RESERVED or (if the transaction was opened with ** BEGIN EXCLUSIVE) EXCLUSIVE lock is obtained on the database file when ** moving to this state, but the journal file is not written to or opened ** to in this state. If the transaction is committed or rolled back while ** in WRITER_LOCKED state, all that is required is to unlock the database ** file. ** ** IN WAL mode, WalBeginWriteTransaction() is called to lock the log file. ** If the connection is running with locking_mode=exclusive, an attempt ** is made to obtain an EXCLUSIVE lock on the database file. ** ** * A write transaction is active. ** * If the connection is open in rollback-mode, a RESERVED or greater ** lock is held on the database file. ** * If the connection is open in WAL-mode, a WAL write transaction ** is open (i.e. sqlite3WalBeginWriteTransaction() has been successfully ** called). ** * The dbSize, dbOrigSize and dbFileSize variables are all valid. ** * The contents of the pager cache have not been modified. ** * The journal file may or may not be open. ** * Nothing (not even the first header) has been written to the journal. ** ** WRITER_CACHEMOD: ** ** A pager moves from WRITER_LOCKED state to this state when a page is ** first modified by the upper layer. In rollback mode the journal file ** is opened (if it is not already open) and a header written to the ** start of it. The database file on disk has not been modified. ** ** * A write transaction is active. ** * A RESERVED or greater lock is held on the database file. ** * The journal file is open and the first header has been written ** to it, but the header has not been synced to disk. ** * The contents of the page cache have been modified. ** |
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258 259 260 261 262 263 264 | ** they upgrade to writers, they may inadvertently corrupt the database ** file. To avoid this hazard, the pager switches into the ERROR state ** instead of READER following such an error. ** ** Once it has entered the ERROR state, any attempt to use the pager ** to read or write data returns an error. Eventually, once all ** outstanding transactions have been abandoned, the pager is able to | | | 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 | ** they upgrade to writers, they may inadvertently corrupt the database ** file. To avoid this hazard, the pager switches into the ERROR state ** instead of READER following such an error. ** ** Once it has entered the ERROR state, any attempt to use the pager ** to read or write data returns an error. Eventually, once all ** outstanding transactions have been abandoned, the pager is able to ** transition back to OPEN state, discarding the contents of the ** page-cache and any other in-memory state at the same time. Everything ** is reloaded from disk (and, if necessary, hot-journal rollback peformed) ** when a read-transaction is next opened on the pager (transitioning ** the pager into READER state). At that point the system has recovered ** from the error. ** ** Specifically, the pager jumps into the ERROR state if: |
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287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 | ** ** Condition (3) is necessary because it can be triggered by a read-only ** statement executed within a transaction. In this case, if the error ** code were simply returned to the user, the b-tree layer would not ** automatically attempt a rollback, as it assumes that an error in a ** read-only statement cannot leave the pager in an internally inconsistent ** state. ** ** ** Notes: ** ** * A pager is never in WRITER_DBMOD or WRITER_FINISHED state if the ** connection is open in WAL mode. A WAL connection is always in one ** of the first four states. ** | > > > > | | | | 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 | ** ** Condition (3) is necessary because it can be triggered by a read-only ** statement executed within a transaction. In this case, if the error ** code were simply returned to the user, the b-tree layer would not ** automatically attempt a rollback, as it assumes that an error in a ** read-only statement cannot leave the pager in an internally inconsistent ** state. ** ** * The Pager.errCode variable is set to something other than SQLITE_OK. ** * There are one or more outstanding references to pages (after the ** last reference is dropped the pager should move back to OPEN state). ** ** ** Notes: ** ** * A pager is never in WRITER_DBMOD or WRITER_FINISHED state if the ** connection is open in WAL mode. A WAL connection is always in one ** of the first four states. ** ** * Normally, a connection open in exclusive mode is never in PAGER_OPEN ** state. There are two exceptions: immediately after exclusive-mode has ** been turned on (and before any read or write transactions are ** executed), and when the pager is leaving the "error state". ** ** * See also: assert_pager_state(). */ #define PAGER_OPEN 0 #define PAGER_READER 1 #define PAGER_WRITER_LOCKED 2 #define PAGER_WRITER_CACHEMOD 3 #define PAGER_WRITER_DBMOD 4 #define PAGER_WRITER_FINISHED 5 #define PAGER_ERROR 6 /* ** The Pager.eLock variable is almost always set to one of the |
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331 332 333 334 335 336 337 | ** at the system level, but it is never set to a more exclusive value. ** ** This is usually safe. If an xUnlock fails or appears to fail, there may ** be a few redundant xLock() calls or a lock may be held for longer than ** required, but nothing really goes wrong. ** ** The exception is when the database file is unlocked as the pager moves | | | | | | 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 | ** at the system level, but it is never set to a more exclusive value. ** ** This is usually safe. If an xUnlock fails or appears to fail, there may ** be a few redundant xLock() calls or a lock may be held for longer than ** required, but nothing really goes wrong. ** ** The exception is when the database file is unlocked as the pager moves ** from ERROR to OPEN state. At this point there may be a hot-journal file ** in the file-system that needs to be rolled back (as part of a OPEN->SHARED ** transition, by the same pager or any other). If the call to xUnlock() ** fails at this point and the pager is left holding an EXCLUSIVE lock, this ** can confuse the call to xCheckReservedLock() call made later as part ** of hot-journal detection. ** ** xCheckReservedLock() is defined as returning true "if there is a RESERVED ** lock held by this process or any others". So xCheckReservedLock may ** return true because the caller itself is holding an EXCLUSIVE lock (but ** doesn't know it because of a previous error in xUnlock). If this happens ** a hot-journal may be mistaken for a journal being created by an active ** transaction in another process, causing SQLite to read from the database ** without rolling it back. ** ** To work around this, if a call to xUnlock() fails when unlocking the ** database in the ERROR state, Pager.eLock is set to UNKNOWN_LOCK. It ** is only changed back to a real locking state after a successful call ** to xLock(EXCLUSIVE). Also, the code to do the OPEN->SHARED state transition ** omits the check for a hot-journal if Pager.eLock is set to UNKNOWN_LOCK ** lock. Instead, it assumes a hot-journal exists and obtains an EXCLUSIVE ** lock on the database file before attempting to roll it back. See function ** PagerSharedLock() for more detail. ** ** Pager.eLock may only be set to UNKNOWN_LOCK when the pager is in ** PAGER_OPEN state. */ #define UNKNOWN_LOCK (EXCLUSIVE_LOCK+1) /* ** A macro used for invoking the codec if there is one */ #ifdef SQLITE_HAS_CODEC |
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408 409 410 411 412 413 414 | Pgno iSubRec; /* Index of first record in sub-journal */ #ifndef SQLITE_OMIT_WAL u32 aWalData[WAL_SAVEPOINT_NDATA]; /* WAL savepoint context */ #endif }; /* | | > | > | | < | < > > | < < | | | | | | > | < < < < < < < < < < < < < < < < < < | | | | | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 | Pgno iSubRec; /* Index of first record in sub-journal */ #ifndef SQLITE_OMIT_WAL u32 aWalData[WAL_SAVEPOINT_NDATA]; /* WAL savepoint context */ #endif }; /* ** A open page cache is an instance of struct Pager. A description of ** some of the more important member variables follows: ** ** eState ** ** The current 'state' of the pager object. See the comment and state ** diagram above for a description of the pager state. ** ** eLock ** ** For a real on-disk database, the current lock held on the database file - ** NO_LOCK, SHARED_LOCK, RESERVED_LOCK or EXCLUSIVE_LOCK. ** ** For a temporary or in-memory database (neither of which require any ** locks), this variable is always set to EXCLUSIVE_LOCK. Since such ** databases always have Pager.exclusiveMode==1, this tricks the pager ** logic into thinking that it already has all the locks it will ever ** need (and no reason to release them). ** ** In some (obscure) circumstances, this variable may also be set to ** UNKNOWN_LOCK. See the comment above the #define of UNKNOWN_LOCK for ** details. ** ** changeCountDone ** ** This boolean variable is used to make sure that the change-counter ** (the 4-byte header field at byte offset 24 of the database file) is ** not updated more often than necessary. ** ** It is set to true when the change-counter field is updated, which ** can only happen if an exclusive lock is held on the database file. ** It is cleared (set to false) whenever an exclusive lock is ** relinquished on the database file. Each time a transaction is committed, ** The changeCountDone flag is inspected. If it is true, the work of ** updating the change-counter is omitted for the current transaction. ** ** This mechanism means that when running in exclusive mode, a connection ** need only update the change-counter once, for the first transaction ** committed. ** ** setMaster ** ** When PagerCommitPhaseOne() is called to commit a transaction, it may ** (or may not) specify a master-journal name to be written into the ** journal file before it is synced to disk. ** ** Whether or not a journal file contains a master-journal pointer affects ** the way in which the journal file is finalized after the transaction is ** committed or rolled back when running in "journal_mode=PERSIST" mode. ** If a journal file does not contain a master-journal pointer, it is ** finalized by overwriting the first journal header with zeroes. If ** it does contain a master-journal pointer the journal file is finalized ** by truncating it to zero bytes, just as if the connection were ** running in "journal_mode=truncate" mode. ** ** Journal files that contain master journal pointers cannot be finalized ** simply by overwriting the first journal-header with zeroes, as the ** master journal pointer could interfere with hot-journal rollback of any ** subsequently interrupted transaction that reuses the journal file. ** ** The flag is cleared as soon as the journal file is finalized (either ** by PagerCommitPhaseTwo or PagerRollback). If an IO error prevents the ** journal file from being successfully finalized, the setMaster flag ** is cleared anyway (and the pager will move to ERROR state). ** ** doNotSpill, doNotSyncSpill ** ** When enabled, cache spills are prohibited. The doNotSpill variable ** inhibits all cache spill and doNotSyncSpill inhibits those spills that ** would require a journal sync. The doNotSyncSpill is set and cleared ** by sqlite3PagerWrite() in order to prevent a journal sync from happening ** in between the journalling of two pages on the same sector. The ** doNotSpill value set to prevent pagerStress() from trying to use ** the journal during a rollback. ** ** subjInMemory ** ** This is a boolean variable. If true, then any required sub-journal ** is opened as an in-memory journal file. If false, then in-memory ** sub-journals are only used for in-memory pager files. ** ** This variable is updated by the upper layer each time a new ** write-transaction is opened. ** ** dbSize, dbOrigSize, dbFileSize ** ** Variable dbSize is set to the number of pages in the database file. ** It is valid in PAGER_READER and higher states (all states except for ** OPEN and ERROR). ** ** dbSize is set based on the size of the database file, which may be ** larger than the size of the database (the value stored at offset ** 28 of the database header by the btree). If the size of the file ** is not an integer multiple of the page-size, the value stored in ** dbSize is rounded down (i.e. a 5KB file with 2K page-size has dbSize==2). ** Except, any file that is greater than 0 bytes in size is considered ** to have at least one page. (i.e. a 1KB file with 2K page-size leads ** to dbSize==1). ** ** During a write-transaction, if pages with page-numbers greater than ** dbSize are modified in the cache, dbSize is updated accordingly. ** Similarly, if the database is truncated using PagerTruncateImage(), ** dbSize is updated. ** ** Variables dbOrigSize and dbFileSize are valid in states ** PAGER_WRITER_LOCKED and higher. dbOrigSize is a copy of the dbSize ** variable at the start of the transaction. It is used during rollback, ** and to determine whether or not pages need to be journalled before ** being modified. ** ** Throughout a write-transaction, dbFileSize contains the size of ** the file on disk in pages. It is set to a copy of dbSize when the ** write-transaction is first opened, and updated when VFS calls are made ** to write or truncate the database file on disk. ** ** errCode ** ** The Pager.errCode variable is only ever used in PAGER_ERROR state. It ** is set to zero in all other states. In PAGER_ERROR state, Pager.errCode ** is always set to SQLITE_FULL, SQLITE_IOERR or one of the SQLITE_IOERR_XXX ** sub-codes. ** ** If Pager.errCode is set to SQLITE_IOERR or one of its subcodes, then ** this value is immediately returned when ever any sqlite3PagerXXX() method ** that returns an error code is called. If it is set to SQLITE_FULL, ** then it is returned whenever any such sqlite3PagerXXX() method except ** for PagerAcquire() or PagerLookup() is called. ** ** TODO: Review the SQLITE_FULL/PagerAcquire() exception. Is it a good idea? ** If so, are there bugs whereby shared-cache clients can see ** uncommitted data when the pager is in the ERROR state? ** */ struct Pager { sqlite3_vfs *pVfs; /* OS functions to use for IO */ u8 exclusiveMode; /* Boolean. True if locking_mode==EXCLUSIVE */ u8 journalMode; /* One of the PAGER_JOURNALMODE_* values */ u8 useJournal; /* Use a rollback journal on this file */ u8 noReadlock; /* Do not bother to obtain readlocks */ |
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530 531 532 533 534 535 536 | ** operates. ** ** The 'state' variable is described in more detail along with the ** descriptions of the values it may take - PAGER_UNLOCK etc. Many of the ** other variables in this block are described in the comment directly ** above this class definition. */ | | | 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 | ** operates. ** ** The 'state' variable is described in more detail along with the ** descriptions of the values it may take - PAGER_UNLOCK etc. Many of the ** other variables in this block are described in the comment directly ** above this class definition. */ u8 eState; /* Pager state (OPEN, READER, WRITER_LOCKED..) */ u8 eLock; /* Current lock held on database file */ u8 changeCountDone; /* Set after incrementing the change-counter */ u8 setMaster; /* True if a m-j name has been written to jrnl */ u8 doNotSpill; /* Do not spill the cache when non-zero */ u8 doNotSyncSpill; /* Do not do a spill that requires jrnl sync */ u8 subjInMemory; /* True to use in-memory sub-journals */ Pgno dbSize; /* Number of pages in the database */ |
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692 693 694 695 696 697 698 699 700 701 702 703 | #endif #ifndef NDEBUG /* ** Usage: ** ** assert( assert_pager_state(pPager) ); */ static int assert_pager_state(Pager *p){ Pager *pPager = p; /* State must be valid. */ | > > > | | | 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 | #endif #ifndef NDEBUG /* ** Usage: ** ** assert( assert_pager_state(pPager) ); ** ** This function runs many asserts to try to find inconsistencies in ** the internal state of the Pager object. */ static int assert_pager_state(Pager *p){ Pager *pPager = p; /* State must be valid. */ assert( p->eState==PAGER_OPEN || p->eState==PAGER_READER || p->eState==PAGER_WRITER_LOCKED || p->eState==PAGER_WRITER_CACHEMOD || p->eState==PAGER_WRITER_DBMOD || p->eState==PAGER_WRITER_FINISHED || p->eState==PAGER_ERROR ); /* Regardless of the current state, a temp-file connection always behaves |
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729 730 731 732 733 734 735 | /* If changeCountDone is set, a RESERVED lock or greater must be held ** on the file. */ assert( pPager->changeCountDone==0 || pPager->eLock>=RESERVED_LOCK ); assert( p->eLock!=PENDING_LOCK ); switch( p->eState ){ | | | | 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 | /* If changeCountDone is set, a RESERVED lock or greater must be held ** on the file. */ assert( pPager->changeCountDone==0 || pPager->eLock>=RESERVED_LOCK ); assert( p->eLock!=PENDING_LOCK ); switch( p->eState ){ case PAGER_OPEN: assert( !MEMDB ); assert( pPager->errCode==SQLITE_OK ); assert( sqlite3PcacheRefCount(pPager->pPCache)==0 || pPager->tempFile ); break; case PAGER_READER: assert( pPager->errCode==SQLITE_OK ); assert( p->eLock!=UNKNOWN_LOCK ); assert( p->eLock>=SHARED_LOCK || p->noReadlock ); break; case PAGER_WRITER_LOCKED: assert( p->eLock!=UNKNOWN_LOCK ); assert( pPager->errCode==SQLITE_OK ); if( !pagerUseWal(pPager) ){ assert( p->eLock>=RESERVED_LOCK ); } assert( pPager->dbSize==pPager->dbOrigSize ); assert( pPager->dbOrigSize==pPager->dbFileSize ); |
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794 795 796 797 798 799 800 | || p->journalMode==PAGER_JOURNALMODE_WAL ); break; case PAGER_ERROR: /* There must be at least one outstanding reference to the pager if ** in ERROR state. Otherwise the pager should have already dropped | | > > > > > | | | | 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 | || p->journalMode==PAGER_JOURNALMODE_WAL ); break; case PAGER_ERROR: /* There must be at least one outstanding reference to the pager if ** in ERROR state. Otherwise the pager should have already dropped ** back to OPEN state. */ assert( pPager->errCode!=SQLITE_OK ); assert( sqlite3PcacheRefCount(pPager->pPCache)>0 ); break; } return 1; } /* ** Return a pointer to a human readable string in a static buffer ** containing the state of the Pager object passed as an argument. This ** is intended to be used within debuggers. For example, as an alternative ** to "print *pPager" in gdb: ** ** (gdb) printf "%s", print_pager_state(pPager) */ static char *print_pager_state(Pager *p){ static char zRet[1024]; sqlite3_snprintf(1024, zRet, "Filename: %s\n" "State: %s errCode=%d\n" "Lock: %s\n" "Locking mode: locking_mode=%s\n" "Journal mode: journal_mode=%s\n" "Backing store: tempFile=%d memDb=%d useJournal=%d\n" "Journal: journalOff=%lld journalHdr=%lld\n" , p->zFilename , p->eState==PAGER_OPEN ? "OPEN" : p->eState==PAGER_READER ? "READER" : p->eState==PAGER_WRITER_LOCKED ? "WRITER_LOCKED" : p->eState==PAGER_WRITER_CACHEMOD ? "WRITER_CACHEMOD" : p->eState==PAGER_WRITER_DBMOD ? "WRITER_DBMOD" : p->eState==PAGER_WRITER_FINISHED ? "WRITER_FINISHED" : p->eState==PAGER_ERROR ? "ERROR" : "?error?" , (int)p->errCode , p->eLock==NO_LOCK ? "OPEN" : p->eLock==RESERVED_LOCK ? "RESERVED" : p->eLock==EXCLUSIVE_LOCK ? "EXCLUSIVE" : p->eLock==SHARED_LOCK ? "SHARED" : p->eLock==UNKNOWN_LOCK ? "UNKNOWN" : "?error?" , p->exclusiveMode ? "exclusive" : "normal" , p->journalMode==PAGER_JOURNALMODE_MEMORY ? "memory" : p->journalMode==PAGER_JOURNALMODE_OFF ? "off" : |
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1586 1587 1588 1589 1590 1591 1592 | sqlite3BitvecDestroy(pPager->pInJournal); pPager->pInJournal = 0; releaseAllSavepoints(pPager); if( pagerUseWal(pPager) ){ assert( !isOpen(pPager->jfd) ); sqlite3WalEndReadTransaction(pPager->pWal); | | | 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 | sqlite3BitvecDestroy(pPager->pInJournal); pPager->pInJournal = 0; releaseAllSavepoints(pPager); if( pagerUseWal(pPager) ){ assert( !isOpen(pPager->jfd) ); sqlite3WalEndReadTransaction(pPager->pWal); pPager->eState = PAGER_OPEN; }else if( !pPager->exclusiveMode ){ int rc; /* Error code returned by pagerUnlockDb() */ int iDc = isOpen(pPager->fd)?sqlite3OsDeviceCharacteristics(pPager->fd):0; /* If the operating system support deletion of open files, then ** close the journal file when dropping the database lock. Otherwise ** another connection with journal_mode=delete might delete the file |
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1618 1619 1620 1621 1622 1623 1624 | ** is necessary. */ rc = pagerUnlockDb(pPager, NO_LOCK); if( rc!=SQLITE_OK && pPager->eState==PAGER_ERROR ){ pPager->eLock = UNKNOWN_LOCK; } | | | | | | 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 | ** is necessary. */ rc = pagerUnlockDb(pPager, NO_LOCK); if( rc!=SQLITE_OK && pPager->eState==PAGER_ERROR ){ pPager->eLock = UNKNOWN_LOCK; } /* The pager state may be changed from PAGER_ERROR to PAGER_OPEN here ** without clearing the error code. This is intentional - the error ** code is cleared and the cache reset in the block below. */ assert( pPager->errCode || pPager->eState!=PAGER_ERROR ); pPager->changeCountDone = 0; pPager->eState = PAGER_OPEN; } /* If Pager.errCode is set, the contents of the pager cache cannot be ** trusted. Now that there are no outstanding references to the pager, ** it can safely move back to PAGER_OPEN state. This happens in both ** normal and exclusive-locking mode. */ if( pPager->errCode && !MEMDB ){ pager_reset(pPager); pPager->changeCountDone = pPager->tempFile; pPager->eState = PAGER_OPEN; pPager->errCode = SQLITE_OK; } pPager->journalOff = 0; pPager->journalHdr = 0; pPager->setMaster = 0; } |
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1741 1742 1743 1744 1745 1746 1747 | static int pager_end_transaction(Pager *pPager, int hasMaster){ int rc = SQLITE_OK; /* Error code from journal finalization operation */ int rc2 = SQLITE_OK; /* Error code from db file unlock operation */ /* Do nothing if the pager does not have an open write transaction. */ assert( assert_pager_state(pPager) ); assert( pPager->eState!=PAGER_ERROR ); | | | 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 | static int pager_end_transaction(Pager *pPager, int hasMaster){ int rc = SQLITE_OK; /* Error code from journal finalization operation */ int rc2 = SQLITE_OK; /* Error code from db file unlock operation */ /* Do nothing if the pager does not have an open write transaction. */ assert( assert_pager_state(pPager) ); assert( pPager->eState!=PAGER_ERROR ); if( pPager->eState<PAGER_WRITER_LOCKED && pPager->eLock<RESERVED_LOCK ){ return SQLITE_OK; } releaseAllSavepoints(pPager); assert( isOpen(pPager->jfd) || pPager->pInJournal==0 ); if( isOpen(pPager->jfd) ){ assert( !pagerUseWal(pPager) ); |
︙ | ︙ | |||
1830 1831 1832 1833 1834 1835 1836 | ** ** If the pager has not already entered the error state, but an IO or ** malloc error occurs during a rollback, then this will itself cause ** the pager to enter the error state. Which will be cleared by the ** call to pager_unlock(), as described above. */ static void pagerUnlockAndRollback(Pager *pPager){ | | | | 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 | ** ** If the pager has not already entered the error state, but an IO or ** malloc error occurs during a rollback, then this will itself cause ** the pager to enter the error state. Which will be cleared by the ** call to pager_unlock(), as described above. */ static void pagerUnlockAndRollback(Pager *pPager){ if( pPager->eState!=PAGER_ERROR && pPager->eState!=PAGER_OPEN ){ assert( assert_pager_state(pPager) ); if( pPager->eState>=PAGER_WRITER_LOCKED ){ sqlite3BeginBenignMalloc(); sqlite3PagerRollback(pPager); sqlite3EndBenignMalloc(); }else if( pPager->eLock>=RESERVED_LOCK && !pPager->exclusiveMode ){ assert( pPager->eState==PAGER_READER ); pager_end_transaction(pPager, 0); } |
︙ | ︙ | |||
1987 1988 1989 1990 1991 1992 1993 | /* If this page has already been played by before during the current ** rollback, then don't bother to play it back again. */ if( pDone && (rc = sqlite3BitvecSet(pDone, pgno))!=SQLITE_OK ){ return rc; } assert( pPager->eState>=PAGER_WRITER_CACHEMOD | | | 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 | /* If this page has already been played by before during the current ** rollback, then don't bother to play it back again. */ if( pDone && (rc = sqlite3BitvecSet(pDone, pgno))!=SQLITE_OK ){ return rc; } assert( pPager->eState>=PAGER_WRITER_CACHEMOD || (pPager->eState==PAGER_OPEN && isMainJrnl) ); /* When playing back page 1, restore the nReserve setting */ if( pgno==1 && pPager->nReserve!=((u8*)aData)[20] ){ pPager->nReserve = ((u8*)aData)[20]; pagerReportSize(pPager); |
︙ | ︙ | |||
2044 2045 2046 2047 2048 2049 2050 | (isMainJrnl?"main-journal":"sub-journal") )); if( isMainJrnl ){ isSynced = pPager->noSync || (*pOffset <= pPager->journalHdr); }else{ isSynced = (pPg==0 || 0==(pPg->flags & PGHDR_NEED_SYNC)); } | | | 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 | (isMainJrnl?"main-journal":"sub-journal") )); if( isMainJrnl ){ isSynced = pPager->noSync || (*pOffset <= pPager->journalHdr); }else{ isSynced = (pPg==0 || 0==(pPg->flags & PGHDR_NEED_SYNC)); } if( (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN) && isOpen(pPager->fd) && isSynced ){ i64 ofst = (pgno-1)*(i64)pPager->pageSize; testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 ); assert( !pagerUseWal(pPager) ); rc = sqlite3OsWrite(pPager->fd, (u8*)aData, pPager->pageSize, ofst); |
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2296 2297 2298 2299 2300 2301 2302 | */ static int pager_truncate(Pager *pPager, Pgno nPage){ int rc = SQLITE_OK; assert( pPager->eState!=PAGER_ERROR ); assert( pPager->eState!=PAGER_READER ); if( isOpen(pPager->fd) | | | 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 | */ static int pager_truncate(Pager *pPager, Pgno nPage){ int rc = SQLITE_OK; assert( pPager->eState!=PAGER_ERROR ); assert( pPager->eState!=PAGER_READER ); if( isOpen(pPager->fd) && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN) ){ i64 currentSize, newSize; /* TODO: Is it safe to use Pager.dbFileSize here? */ rc = sqlite3OsFileSize(pPager->fd, ¤tSize); newSize = pPager->pageSize*(i64)nPage; if( rc==SQLITE_OK && currentSize!=newSize ){ if( currentSize>newSize ){ |
︙ | ︙ | |||
2781 2782 2783 2784 2785 2786 2787 | ** other writers or checkpointers. */ static int pagerBeginReadTransaction(Pager *pPager){ int rc; /* Return code */ int changed = 0; /* True if cache must be reset */ assert( pagerUseWal(pPager) ); | | | 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 | ** other writers or checkpointers. */ static int pagerBeginReadTransaction(Pager *pPager){ int rc; /* Return code */ int changed = 0; /* True if cache must be reset */ assert( pagerUseWal(pPager) ); assert( pPager->eState==PAGER_OPEN || pPager->eState==PAGER_READER ); /* sqlite3WalEndReadTransaction() was not called for the previous ** transaction in locking_mode=EXCLUSIVE. So call it now. If we ** are in locking_mode=NORMAL and EndRead() was previously called, ** the duplicate call is harmless. */ sqlite3WalEndReadTransaction(pPager->pWal); |
︙ | ︙ | |||
2805 2806 2807 2808 2809 2810 2811 | /* ** TODO: Description here. */ static int pagerPagecount(Pager *pPager, Pgno *pnPage){ Pgno nPage; /* Value to return via *pnPage */ | | | 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 | /* ** TODO: Description here. */ static int pagerPagecount(Pager *pPager, Pgno *pnPage){ Pgno nPage; /* Value to return via *pnPage */ assert( pPager->eState==PAGER_OPEN ); nPage = sqlite3WalDbsize(pPager->pWal); if( nPage==0 ){ i64 n = 0; /* Size of db file in bytes */ assert( isOpen(pPager->fd) || pPager->tempFile ); if( isOpen(pPager->fd) ){ int rc = sqlite3OsFileSize(pPager->fd, &n); if( rc!=SQLITE_OK ){ |
︙ | ︙ | |||
2861 2862 2863 2864 2865 2866 2867 | */ static int pagerOpenWalIfPresent(Pager *pPager){ int rc = SQLITE_OK; if( !pPager->tempFile ){ int isWal; /* True if WAL file exists */ Pgno nPage; /* Size of the database file */ | | | 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 | */ static int pagerOpenWalIfPresent(Pager *pPager){ int rc = SQLITE_OK; if( !pPager->tempFile ){ int isWal; /* True if WAL file exists */ Pgno nPage; /* Size of the database file */ assert( pPager->eState==PAGER_OPEN ); assert( pPager->eLock>=SHARED_LOCK || pPager->noReadlock ); rc = pagerPagecount(pPager, &nPage); if( rc ) return rc; if( nPage==0 ){ rc = sqlite3OsDelete(pPager->pVfs, pPager->zWal, 0); isWal = 0; }else{ |
︙ | ︙ | |||
2932 2933 2934 2935 2936 2937 2938 | static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){ i64 szJ; /* Effective size of the main journal */ i64 iHdrOff; /* End of first segment of main-journal records */ int rc = SQLITE_OK; /* Return code */ Bitvec *pDone = 0; /* Bitvec to ensure pages played back only once */ assert( pPager->eState!=PAGER_ERROR ); | | | 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 | static int pagerPlaybackSavepoint(Pager *pPager, PagerSavepoint *pSavepoint){ i64 szJ; /* Effective size of the main journal */ i64 iHdrOff; /* End of first segment of main-journal records */ int rc = SQLITE_OK; /* Return code */ Bitvec *pDone = 0; /* Bitvec to ensure pages played back only once */ assert( pPager->eState!=PAGER_ERROR ); assert( pPager->eState>=PAGER_WRITER_LOCKED ); /* Allocate a bitvec to use to store the set of pages rolled back */ if( pSavepoint ){ pDone = sqlite3BitvecCreate(pSavepoint->nOrig); if( !pDone ){ return SQLITE_NOMEM; } |
︙ | ︙ | |||
3194 3195 3196 3197 3198 3199 3200 | assert( pageSize==0 || (pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE) ); if( (pPager->memDb==0 || pPager->dbSize==0) && sqlite3PcacheRefCount(pPager->pPCache)==0 && pageSize && pageSize!=pPager->pageSize ){ char *pNew; /* New temp space */ i64 nByte = 0; | | | 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 | assert( pageSize==0 || (pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE) ); if( (pPager->memDb==0 || pPager->dbSize==0) && sqlite3PcacheRefCount(pPager->pPCache)==0 && pageSize && pageSize!=pPager->pageSize ){ char *pNew; /* New temp space */ i64 nByte = 0; if( pPager->eState>PAGER_OPEN && isOpen(pPager->fd) ){ rc = sqlite3OsFileSize(pPager->fd, &nByte); if( rc!=SQLITE_OK ) return rc; } pNew = (char *)sqlite3PageMalloc(pageSize); if( !pNew ){ rc = SQLITE_NOMEM; }else{ |
︙ | ︙ | |||
3242 3243 3244 3245 3246 3247 3248 | ** ** Regardless of mxPage, return the current maximum page count. */ int sqlite3PagerMaxPageCount(Pager *pPager, int mxPage){ if( mxPage>0 ){ pPager->mxPgno = mxPage; } | | | 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 | ** ** Regardless of mxPage, return the current maximum page count. */ int sqlite3PagerMaxPageCount(Pager *pPager, int mxPage){ if( mxPage>0 ){ pPager->mxPgno = mxPage; } if( pPager->eState!=PAGER_OPEN && pPager->mxPgno<pPager->dbSize ){ pPager->mxPgno = pPager->dbSize; } return pPager->mxPgno; } /* ** The following set of routines are used to disable the simulated |
︙ | ︙ | |||
3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 | ** ** If everything is successful, SQLITE_OK is returned. If an IO error ** occurs, an IO error code is returned. Or, if the EXCLUSIVE lock cannot ** be obtained, SQLITE_BUSY is returned. */ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){ int rc; /* Return code */ /* At this point there may be either a RESERVED or EXCLUSIVE lock on the ** database file. If there is already an EXCLUSIVE lock, the following ** call is a no-op. ** ** Moving the lock from RESERVED to EXCLUSIVE actually involves going ** through an intermediate state PENDING. A PENDING lock prevents new ** readers from attaching to the database but is unsufficient for us to ** write. The idea of a PENDING lock is to prevent new readers from ** coming in while we wait for existing readers to clear. ** ** While the pager is in the RESERVED state, the original database file ** is unchanged and we can rollback without having to playback the ** journal into the original database file. Once we transition to ** EXCLUSIVE, it means the database file has been changed and any rollback ** will require a journal playback. */ | > > > > > > > > > > > > > > > > < < < < < < < < < < < < < < < < < | 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 | ** ** If everything is successful, SQLITE_OK is returned. If an IO error ** occurs, an IO error code is returned. Or, if the EXCLUSIVE lock cannot ** be obtained, SQLITE_BUSY is returned. */ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){ int rc; /* Return code */ /* Normally, this function is called in WRITER_DBMOD state. ** ** However it may be called in WRITER_CACHEMOD state if the page being ** written (and all other pages that reside on the same disk sector) was ** a free-list leaf page at the start of the transaction. In that case ** the database file is not really being modified, so it is Ok to write ** to it in CACHEMOD state. */ assert( !pagerUseWal(pPager) ); assert( pPager->eState==PAGER_WRITER_DBMOD || pPager->eState==PAGER_WRITER_CACHEMOD ); assert( pPager->eState==PAGER_WRITER_DBMOD || (pList->pDirty==0 && pList->pgno<=pPager->dbFileSize) ); /* At this point there may be either a RESERVED or EXCLUSIVE lock on the ** database file. If there is already an EXCLUSIVE lock, the following ** call is a no-op. ** ** Moving the lock from RESERVED to EXCLUSIVE actually involves going ** through an intermediate state PENDING. A PENDING lock prevents new ** readers from attaching to the database but is unsufficient for us to ** write. The idea of a PENDING lock is to prevent new readers from ** coming in while we wait for existing readers to clear. ** ** While the pager is in the RESERVED state, the original database file ** is unchanged and we can rollback without having to playback the ** journal into the original database file. Once we transition to ** EXCLUSIVE, it means the database file has been changed and any rollback ** will require a journal playback. */ rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK); /* If the file is a temp-file has not yet been opened, open it now. It ** is not possible for rc to be other than SQLITE_OK if this branch ** is taken, as pager_wait_on_lock() is a no-op for temp-files. */ if( !isOpen(pPager->fd) ){ |
︙ | ︙ | |||
4314 4315 4316 4317 4318 4319 4320 | sqlite3_vfs * const pVfs = pPager->pVfs; int rc = SQLITE_OK; /* Return code */ int exists = 1; /* True if a journal file is present */ int jrnlOpen = !!isOpen(pPager->jfd); assert( pPager->useJournal ); assert( isOpen(pPager->fd) ); | | | 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 | sqlite3_vfs * const pVfs = pPager->pVfs; int rc = SQLITE_OK; /* Return code */ int exists = 1; /* True if a journal file is present */ int jrnlOpen = !!isOpen(pPager->jfd); assert( pPager->useJournal ); assert( isOpen(pPager->fd) ); assert( pPager->eState==PAGER_OPEN ); assert( jrnlOpen==0 || ( sqlite3OsDeviceCharacteristics(pPager->jfd) & SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN )); *pExists = 0; if( !jrnlOpen ){ |
︙ | ︙ | |||
4433 4434 4435 4436 4437 4438 4439 | ** file or rolling back a journal file, the IO error code is returned. */ int sqlite3PagerSharedLock(Pager *pPager){ int rc = SQLITE_OK; /* Return code */ /* This routine is only called from b-tree and only when there are no ** outstanding pages. This implies that the pager state should either | | | | | 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 | ** file or rolling back a journal file, the IO error code is returned. */ int sqlite3PagerSharedLock(Pager *pPager){ int rc = SQLITE_OK; /* Return code */ /* This routine is only called from b-tree and only when there are no ** outstanding pages. This implies that the pager state should either ** be OPEN or READER. READER is only possible if the pager is or was in ** exclusive access mode. */ assert( sqlite3PcacheRefCount(pPager->pPCache)==0 ); assert( assert_pager_state(pPager) ); assert( pPager->eState==PAGER_OPEN || pPager->eState==PAGER_READER ); if( NEVER(MEMDB && pPager->errCode) ){ return pPager->errCode; } if( !pagerUseWal(pPager) && pPager->eState==PAGER_OPEN ){ int bHotJournal = 1; /* True if there exists a hot journal-file */ assert( !MEMDB ); assert( pPager->noReadlock==0 || pPager->readOnly ); if( pPager->noReadlock==0 ){ rc = pager_wait_on_lock(pPager, SHARED_LOCK); |
︙ | ︙ | |||
4529 4530 4531 4532 4533 4534 4535 | ** the journal before playing it back. */ if( isOpen(pPager->jfd) ){ assert( rc==SQLITE_OK ); rc = pagerSyncHotJournal(pPager); if( rc==SQLITE_OK ){ rc = pager_playback(pPager, 1); | | > > > > > > > > > > > > > > > > | | 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 | ** the journal before playing it back. */ if( isOpen(pPager->jfd) ){ assert( rc==SQLITE_OK ); rc = pagerSyncHotJournal(pPager); if( rc==SQLITE_OK ){ rc = pager_playback(pPager, 1); pPager->eState = PAGER_OPEN; } }else if( !pPager->exclusiveMode ){ pagerUnlockDb(pPager, SHARED_LOCK); } if( rc!=SQLITE_OK ){ /* This branch is taken if an error occurs while trying to open ** or roll back a hot-journal while holding an EXCLUSIVE lock. The ** pager_unlock() routine will be called before returning to unlock ** the file. If the unlock attempt fails, then Pager.eLock must be ** set to UNKNOWN_LOCK (see the comment above the #define for ** UNKNOWN_LOCK above for an explanation). ** ** In order to get pager_unlock() to do this, set Pager.eState to ** PAGER_ERROR now. This is not actually counted as a transition ** to ERROR state in the state diagram at the top of this file, ** since we know that the same call to pager_unlock() will very ** shortly transition the pager object to the OPEN state. Calling ** assert_pager_state() would fail now, as it should not be possible ** to be in ERROR state when there are zero outstanding page ** references. */ pager_error(pPager, rc); goto failed; } assert( pPager->eState==PAGER_OPEN ); assert( (pPager->eLock==SHARED_LOCK) || (pPager->exclusiveMode && pPager->eLock>SHARED_LOCK) ); } if( !pPager->tempFile && (pPager->pBackup || sqlite3PcachePagecount(pPager->pPCache)>0) |
︙ | ︙ | |||
4596 4597 4598 4599 4600 4601 4602 | rc = pagerOpenWalIfPresent(pPager); } if( pagerUseWal(pPager) && rc==SQLITE_OK ){ rc = pagerBeginReadTransaction(pPager); } | | | | 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 | rc = pagerOpenWalIfPresent(pPager); } if( pagerUseWal(pPager) && rc==SQLITE_OK ){ rc = pagerBeginReadTransaction(pPager); } if( pPager->eState==PAGER_OPEN && rc==SQLITE_OK ){ rc = pagerPagecount(pPager, &pPager->dbSize); } failed: if( rc!=SQLITE_OK ){ pager_unlock(pPager); assert( pPager->eState==PAGER_OPEN ); }else{ pPager->eState = PAGER_READER; } return rc; } /* |
︙ | ︙ | |||
4843 4844 4845 4846 4847 4848 4849 | ** SQLITE_NOMEM if the attempt to allocate Pager.pInJournal fails, or ** an IO error code if opening or writing the journal file fails. */ static int pager_open_journal(Pager *pPager){ int rc = SQLITE_OK; /* Return code */ sqlite3_vfs * const pVfs = pPager->pVfs; /* Local cache of vfs pointer */ | | | 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 | ** SQLITE_NOMEM if the attempt to allocate Pager.pInJournal fails, or ** an IO error code if opening or writing the journal file fails. */ static int pager_open_journal(Pager *pPager){ int rc = SQLITE_OK; /* Return code */ sqlite3_vfs * const pVfs = pPager->pVfs; /* Local cache of vfs pointer */ assert( pPager->eState==PAGER_WRITER_LOCKED ); assert( assert_pager_state(pPager) ); assert( pPager->pInJournal==0 ); /* If already in the error state, this function is a no-op. But on ** the other hand, this routine is never called if we are already in ** an error state. */ if( NEVER(pPager->errCode) ) return pPager->errCode; |
︙ | ︙ | |||
4898 4899 4900 4901 4902 4903 4904 | } } if( rc!=SQLITE_OK ){ sqlite3BitvecDestroy(pPager->pInJournal); pPager->pInJournal = 0; }else{ | | | 4974 4975 4976 4977 4978 4979 4980 4981 4982 4983 4984 4985 4986 4987 4988 | } } if( rc!=SQLITE_OK ){ sqlite3BitvecDestroy(pPager->pInJournal); pPager->pInJournal = 0; }else{ assert( pPager->eState==PAGER_WRITER_LOCKED ); pPager->eState = PAGER_WRITER_CACHEMOD; } return rc; } /* |
︙ | ︙ | |||
4970 4971 4972 4973 4974 4975 4976 | if( rc==SQLITE_OK && exFlag ){ rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK); } } if( rc==SQLITE_OK ){ | | | | < < < < < < < | | 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068 5069 5070 5071 5072 5073 5074 5075 | if( rc==SQLITE_OK && exFlag ){ rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK); } } if( rc==SQLITE_OK ){ /* Change to WRITER_LOCKED state. ** ** WAL mode sets Pager.eState to PAGER_WRITER_LOCKED or CACHEMOD ** when it has an open transaction, but never to DBMOD or FINISHED. ** This is because in those states the code to roll back savepoint ** transactions may copy data from the sub-journal into the database ** file as well as into the page cache. Which would be incorrect in ** WAL mode. */ pPager->eState = PAGER_WRITER_LOCKED; pPager->dbFileSize = pPager->dbOrigSize = pPager->dbSize; pPager->journalOff = 0; } assert( rc==SQLITE_OK || pPager->eState==PAGER_READER ); assert( rc!=SQLITE_OK || pPager->eState==PAGER_WRITER_LOCKED ); assert( assert_pager_state(pPager) ); } PAGERTRACE(("TRANSACTION %d\n", PAGERID(pPager))); return rc; } |
︙ | ︙ | |||
5016 5017 5018 5019 5020 5021 5022 | Pager *pPager = pPg->pPager; int rc = SQLITE_OK; /* This routine is not called unless a write-transaction has already ** been started. The journal file may or may not be open at this point. ** It is never called in the ERROR state. */ | | | 5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 | Pager *pPager = pPg->pPager; int rc = SQLITE_OK; /* This routine is not called unless a write-transaction has already ** been started. The journal file may or may not be open at this point. ** It is never called in the ERROR state. */ assert( pPager->eState==PAGER_WRITER_LOCKED || pPager->eState==PAGER_WRITER_CACHEMOD || pPager->eState==PAGER_WRITER_DBMOD ); assert( assert_pager_state(pPager) ); /* If an error has been previously detected, report the same error ** again. This should not happen, but the check provides robustness. */ |
︙ | ︙ | |||
5049 5050 5051 5052 5053 5054 5055 | ** written to the transaction journal or the checkpoint journal ** or both. ** ** Higher level routines have already obtained the necessary locks ** to begin the write-transaction, but the rollback journal might not ** yet be open. Open it now if this is the case. */ | | | 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 | ** written to the transaction journal or the checkpoint journal ** or both. ** ** Higher level routines have already obtained the necessary locks ** to begin the write-transaction, but the rollback journal might not ** yet be open. Open it now if this is the case. */ if( pPager->eState==PAGER_WRITER_LOCKED ){ rc = pager_open_journal(pPager); if( rc!=SQLITE_OK ) return rc; } assert( pPager->eState>=PAGER_WRITER_CACHEMOD ); assert( assert_pager_state(pPager) ); /* The transaction journal now exists and we have a RESERVED or an |
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5166 5167 5168 5169 5170 5171 5172 | int sqlite3PagerWrite(DbPage *pDbPage){ int rc = SQLITE_OK; PgHdr *pPg = pDbPage; Pager *pPager = pPg->pPager; Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize); | | | 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 | int sqlite3PagerWrite(DbPage *pDbPage){ int rc = SQLITE_OK; PgHdr *pPg = pDbPage; Pager *pPager = pPg->pPager; Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize); assert( pPager->eState>=PAGER_WRITER_LOCKED ); assert( pPager->eState!=PAGER_ERROR ); assert( assert_pager_state(pPager) ); if( nPagePerSector>1 ){ Pgno nPageCount; /* Total number of pages in database file */ Pgno pg1; /* First page of the sector pPg is located on. */ int nPage = 0; /* Number of pages starting at pg1 to journal */ |
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5415 5416 5417 5418 5419 5420 5421 | ** Otherwise, either SQLITE_BUSY or an SQLITE_IOERR_XXX error code is ** returned. */ int sqlite3PagerExclusiveLock(Pager *pPager){ int rc = SQLITE_OK; assert( pPager->eState==PAGER_WRITER_CACHEMOD || pPager->eState==PAGER_WRITER_DBMOD | | | 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 | ** Otherwise, either SQLITE_BUSY or an SQLITE_IOERR_XXX error code is ** returned. */ int sqlite3PagerExclusiveLock(Pager *pPager){ int rc = SQLITE_OK; assert( pPager->eState==PAGER_WRITER_CACHEMOD || pPager->eState==PAGER_WRITER_DBMOD || pPager->eState==PAGER_WRITER_LOCKED ); assert( assert_pager_state(pPager) ); if( 0==pagerUseWal(pPager) ){ rc = pager_wait_on_lock(pPager, EXCLUSIVE_LOCK); } return rc; } |
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5457 5458 5459 5460 5461 5462 5463 | int sqlite3PagerCommitPhaseOne( Pager *pPager, /* Pager object */ const char *zMaster, /* If not NULL, the master journal name */ int noSync /* True to omit the xSync on the db file */ ){ int rc = SQLITE_OK; /* Return code */ | | > | 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536 5537 5538 5539 5540 5541 5542 5543 | int sqlite3PagerCommitPhaseOne( Pager *pPager, /* Pager object */ const char *zMaster, /* If not NULL, the master journal name */ int noSync /* True to omit the xSync on the db file */ ){ int rc = SQLITE_OK; /* Return code */ assert( pPager->eState==PAGER_WRITER_LOCKED || pPager->eState==PAGER_WRITER_CACHEMOD || pPager->eState==PAGER_WRITER_DBMOD || pPager->eState==PAGER_WRITER_ERROR ); assert( assert_pager_state(pPager) ); /* If a prior error occurred, report that error again. */ if( pPager->errCode ) return pPager->errCode; PAGERTRACE(("DATABASE SYNC: File=%s zMaster=%s nSize=%d\n", |
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5654 5655 5656 5657 5658 5659 5660 | int rc = SQLITE_OK; /* Return code */ /* This routine should not be called if a prior error has occurred. ** But if (due to a coding error elsewhere in the system) it does get ** called, just return the same error code without doing anything. */ if( NEVER(pPager->errCode) ) return pPager->errCode; | | | | 5724 5725 5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 | int rc = SQLITE_OK; /* Return code */ /* This routine should not be called if a prior error has occurred. ** But if (due to a coding error elsewhere in the system) it does get ** called, just return the same error code without doing anything. */ if( NEVER(pPager->errCode) ) return pPager->errCode; assert( pPager->eState==PAGER_WRITER_LOCKED || pPager->eState==PAGER_WRITER_FINISHED || (pagerUseWal(pPager) && pPager->eState==PAGER_WRITER_CACHEMOD) ); assert( assert_pager_state(pPager) ); /* An optimization. If the database was not actually modified during ** this transaction, the pager is running in exclusive-mode and is ** using persistent journals, then this function is a no-op. ** ** The start of the journal file currently contains a single journal ** header with the nRec field set to 0. If such a journal is used as ** a hot-journal during hot-journal rollback, 0 changes will be made ** to the database file. So there is no need to zero the journal ** header. Since the pager is in exclusive mode, there is no need ** to drop any locks either. */ if( pPager->eState==PAGER_WRITER_LOCKED && pPager->exclusiveMode && pPager->journalMode==PAGER_JOURNALMODE_PERSIST ){ assert( pPager->journalOff==JOURNAL_HDR_SZ(pPager) || !pPager->journalOff ); pPager->eState = PAGER_READER; return SQLITE_OK; } |
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5732 5733 5734 5735 5736 5737 5738 | ** some other process can use it to restore the database state (by ** hot-journal rollback). */ int sqlite3PagerRollback(Pager *pPager){ int rc = SQLITE_OK; /* Return code */ PAGERTRACE(("ROLLBACK %d\n", PAGERID(pPager))); | | | 5802 5803 5804 5805 5806 5807 5808 5809 5810 5811 5812 5813 5814 5815 5816 | ** some other process can use it to restore the database state (by ** hot-journal rollback). */ int sqlite3PagerRollback(Pager *pPager){ int rc = SQLITE_OK; /* Return code */ PAGERTRACE(("ROLLBACK %d\n", PAGERID(pPager))); /* PagerRollback() is a no-op if called in READER or OPEN state. If ** the pager is already in the ERROR state, the rollback is not ** attempted here. Instead, the error code is returned to the caller. */ assert( assert_pager_state(pPager) ); if( pPager->eState==PAGER_ERROR ) return pPager->errCode; if( pPager->eState<=PAGER_READER ) return SQLITE_OK; |
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5802 5803 5804 5805 5806 5807 5808 | ** This routine is used for testing and analysis only. */ int *sqlite3PagerStats(Pager *pPager){ static int a[11]; a[0] = sqlite3PcacheRefCount(pPager->pPCache); a[1] = sqlite3PcachePagecount(pPager->pPCache); a[2] = sqlite3PcacheGetCachesize(pPager->pPCache); | | | 5872 5873 5874 5875 5876 5877 5878 5879 5880 5881 5882 5883 5884 5885 5886 | ** This routine is used for testing and analysis only. */ int *sqlite3PagerStats(Pager *pPager){ static int a[11]; a[0] = sqlite3PcacheRefCount(pPager->pPCache); a[1] = sqlite3PcachePagecount(pPager->pPCache); a[2] = sqlite3PcacheGetCachesize(pPager->pPCache); a[3] = pPager->eState==PAGER_OPEN ? -1 : (int) pPager->dbSize; a[4] = pPager->eState; a[5] = pPager->errCode; a[6] = pPager->nHit; a[7] = pPager->nMiss; a[8] = 0; /* Used to be pPager->nOvfl */ a[9] = pPager->nRead; a[10] = pPager->nWrite; |
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5835 5836 5837 5838 5839 5840 5841 | ** occurs while opening the sub-journal file, then an IO error code is ** returned. Otherwise, SQLITE_OK. */ int sqlite3PagerOpenSavepoint(Pager *pPager, int nSavepoint){ int rc = SQLITE_OK; /* Return code */ int nCurrent = pPager->nSavepoint; /* Current number of savepoints */ | | | 5905 5906 5907 5908 5909 5910 5911 5912 5913 5914 5915 5916 5917 5918 5919 | ** occurs while opening the sub-journal file, then an IO error code is ** returned. Otherwise, SQLITE_OK. */ int sqlite3PagerOpenSavepoint(Pager *pPager, int nSavepoint){ int rc = SQLITE_OK; /* Return code */ int nCurrent = pPager->nSavepoint; /* Current number of savepoints */ assert( pPager->eState>=PAGER_WRITER_LOCKED ); assert( assert_pager_state(pPager) ); if( nSavepoint>nCurrent && pPager->useJournal ){ int ii; /* Iterator variable */ PagerSavepoint *aNew; /* New Pager.aSavepoint array */ /* Grow the Pager.aSavepoint array using realloc(). Return SQLITE_NOMEM |
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6288 6289 6290 6291 6292 6293 6294 | ** ** Before deleting the journal file, obtain a RESERVED lock on the ** database file. This ensures that the journal file is not deleted ** while it is in use by some other client. */ int rc = SQLITE_OK; int state = pPager->eState; | | | | 6358 6359 6360 6361 6362 6363 6364 6365 6366 6367 6368 6369 6370 6371 6372 6373 6374 6375 6376 6377 6378 6379 6380 6381 6382 6383 6384 | ** ** Before deleting the journal file, obtain a RESERVED lock on the ** database file. This ensures that the journal file is not deleted ** while it is in use by some other client. */ int rc = SQLITE_OK; int state = pPager->eState; if( state==PAGER_OPEN ){ rc = sqlite3PagerSharedLock(pPager); } if( pPager->eState==PAGER_READER ){ assert( rc==SQLITE_OK ); rc = pagerLockDb(pPager, RESERVED_LOCK); } if( rc==SQLITE_OK ){ sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0); } if( rc==SQLITE_OK && state==PAGER_READER ){ pagerUnlockDb(pPager, SHARED_LOCK); }else if( state==PAGER_OPEN ){ pager_unlock(pPager); } assert( state==pPager->eState ); } } /* Return the new journal mode */ |
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6404 6405 6406 6407 6408 6409 6410 | int sqlite3PagerOpenWal( Pager *pPager, /* Pager object */ int *pbOpen /* OUT: Set to true if call is a no-op */ ){ int rc = SQLITE_OK; /* Return code */ assert( assert_pager_state(pPager) ); | | | | 6474 6475 6476 6477 6478 6479 6480 6481 6482 6483 6484 6485 6486 6487 6488 6489 6490 6491 6492 6493 6494 6495 6496 6497 6498 6499 6500 6501 6502 6503 6504 6505 6506 6507 | int sqlite3PagerOpenWal( Pager *pPager, /* Pager object */ int *pbOpen /* OUT: Set to true if call is a no-op */ ){ int rc = SQLITE_OK; /* Return code */ assert( assert_pager_state(pPager) ); assert( pPager->eState==PAGER_OPEN || pbOpen ); assert( pPager->eState==PAGER_READER || !pbOpen ); assert( pbOpen==0 || *pbOpen==0 ); assert( pbOpen!=0 || (!pPager->tempFile && !pPager->pWal) ); if( !pPager->tempFile && !pPager->pWal ){ if( !sqlite3PagerWalSupported(pPager) ) return SQLITE_CANTOPEN; if( isOpen(pPager->jfd) ){ sqlite3OsClose(pPager->jfd); } /* Open the connection to the log file. If this operation fails, ** (e.g. due to malloc() failure), unlock the database file and ** return an error code. */ rc = sqlite3WalOpen(pPager->pVfs, pPager->fd, pPager->zWal, &pPager->pWal); if( rc==SQLITE_OK ){ pPager->journalMode = PAGER_JOURNALMODE_WAL; pPager->eState = PAGER_OPEN; } }else{ *pbOpen = 1; } return rc; } |
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