Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
Comment: | Add variable pager.dbHintSize, used to limit the number of calls made to the xFileControl(FCNTL_SIZE_HINT) method. |
---|---|
Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | experimental |
Files: | files | file ages | folders |
SHA1: |
eb3ac895bd92c880ac6acca58de8cf96 |
User & Date: | dan 2010-08-10 09:58:57.000 |
Context
2010-08-10
| ||
15:46 | Fix a bug in pager.c causing it to omit the xSync() call required following a hot-journal rollback. (Closed-Leaf check-in: 42ba43ac69 user: dan tags: experimental) | |
09:58 | Add variable pager.dbHintSize, used to limit the number of calls made to the xFileControl(FCNTL_SIZE_HINT) method. (check-in: eb3ac895bd user: dan tags: experimental) | |
2010-08-09
| ||
19:17 | Modify some comments in pager.c. (check-in: 5662da6d4f user: dan tags: experimental) | |
Changes
Changes to src/pager.c.
︙ | ︙ | |||
561 562 563 564 565 566 567 | ** 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 | | > > > > > > > > > > > > > > > > > > > > > > > | 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 | ** 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. ** ** The only reason the dbFileSize variable is required is to suppress ** unnecessary calls to xTruncate() after committing a transaction. If, ** when a transaction is committed, the dbFileSize variable indicates ** that the database file is larger than the database image (Pager.dbSize), ** pager_truncate() is called. The pager_truncate() call uses xFilesize() ** to measure the database file on disk, and then truncates it if required. ** dbFileSize is not used when rolling back a transaction. In this case ** pager_truncate() is called unconditionally (which means there may be ** a call to xFilesize() that is not strictly required). In either case, ** pager_truncate() may cause the file to become smaller or larger. ** ** dbHintSize ** ** The dbHintSize variable is used to limit the number of calls made to ** the VFS xFileControl(FCNTL_SIZE_HINT) method. ** ** dbHintSize is set to a copy of the dbSize variable when a ** write-transaction is opened (at the same time as dbFileSize and ** dbOrigSize). If the xFileControl(FCNTL_SIZE_HINT) method is called, ** dbHintSize is increased to the number of pages that correspond to the ** size-hint passed to the method call. See pager_write_pagelist() for ** details. ** ** 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. |
︙ | ︙ | |||
615 616 617 618 619 620 621 622 623 624 625 626 627 628 | 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 */ Pgno dbOrigSize; /* dbSize before the current transaction */ Pgno dbFileSize; /* Number of pages in the database file */ int errCode; /* One of several kinds of errors */ int nRec; /* Pages journalled since last j-header written */ u32 cksumInit; /* Quasi-random value added to every checksum */ u32 nSubRec; /* Number of records written to sub-journal */ Bitvec *pInJournal; /* One bit for each page in the database file */ sqlite3_file *fd; /* File descriptor for database */ sqlite3_file *jfd; /* File descriptor for main journal */ | > | 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 | 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 */ Pgno dbOrigSize; /* dbSize before the current transaction */ Pgno dbFileSize; /* Number of pages in the database file */ Pgno dbHintSize; /* Value passed to FCNTL_SIZE_HINT call */ int errCode; /* One of several kinds of errors */ int nRec; /* Pages journalled since last j-header written */ u32 cksumInit; /* Quasi-random value added to every checksum */ u32 nSubRec; /* Number of records written to sub-journal */ Bitvec *pInJournal; /* One bit for each page in the database file */ sqlite3_file *fd; /* File descriptor for database */ sqlite3_file *jfd; /* File descriptor for main journal */ |
︙ | ︙ | |||
827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 | 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 ); assert( pPager->setMaster==0 ); break; case PAGER_WRITER_CACHEMOD: assert( p->eLock!=UNKNOWN_LOCK ); assert( pPager->errCode==SQLITE_OK ); if( !pagerUseWal(pPager) ){ /* It is possible that if journal_mode=wal here that neither the ** journal file nor the WAL file are open. This happens during ** a rollback transaction that switches from journal_mode=off ** to journal_mode=wal. */ assert( p->eLock>=RESERVED_LOCK ); assert( isOpen(p->jfd) || p->journalMode==PAGER_JOURNALMODE_OFF || p->journalMode==PAGER_JOURNALMODE_WAL ); } assert( pPager->dbOrigSize==pPager->dbFileSize ); break; case PAGER_WRITER_DBMOD: assert( p->eLock==EXCLUSIVE_LOCK ); assert( pPager->errCode==SQLITE_OK ); assert( !pagerUseWal(pPager) ); assert( p->eLock>=EXCLUSIVE_LOCK ); assert( isOpen(p->jfd) || p->journalMode==PAGER_JOURNALMODE_OFF || p->journalMode==PAGER_JOURNALMODE_WAL ); break; case PAGER_WRITER_FINISHED: assert( p->eLock==EXCLUSIVE_LOCK ); assert( pPager->errCode==SQLITE_OK ); assert( !pagerUseWal(pPager) ); assert( isOpen(p->jfd) | > > > | 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 | 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 ); assert( pPager->dbOrigSize==pPager->dbHintSize ); assert( pPager->setMaster==0 ); break; case PAGER_WRITER_CACHEMOD: assert( p->eLock!=UNKNOWN_LOCK ); assert( pPager->errCode==SQLITE_OK ); if( !pagerUseWal(pPager) ){ /* It is possible that if journal_mode=wal here that neither the ** journal file nor the WAL file are open. This happens during ** a rollback transaction that switches from journal_mode=off ** to journal_mode=wal. */ assert( p->eLock>=RESERVED_LOCK ); assert( isOpen(p->jfd) || p->journalMode==PAGER_JOURNALMODE_OFF || p->journalMode==PAGER_JOURNALMODE_WAL ); } assert( pPager->dbOrigSize==pPager->dbFileSize ); assert( pPager->dbOrigSize==pPager->dbHintSize ); break; case PAGER_WRITER_DBMOD: assert( p->eLock==EXCLUSIVE_LOCK ); assert( pPager->errCode==SQLITE_OK ); assert( !pagerUseWal(pPager) ); assert( p->eLock>=EXCLUSIVE_LOCK ); assert( isOpen(p->jfd) || p->journalMode==PAGER_JOURNALMODE_OFF || p->journalMode==PAGER_JOURNALMODE_WAL ); assert( pPager->dbOrigSize<=pPager->dbHintSize ); break; case PAGER_WRITER_FINISHED: assert( p->eLock==EXCLUSIVE_LOCK ); assert( pPager->errCode==SQLITE_OK ); assert( !pagerUseWal(pPager) ); assert( isOpen(p->jfd) |
︙ | ︙ | |||
3825 3826 3827 3828 3829 3830 3831 | ** the database file. ** ** 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){ | | | < < < < < < < | < < | < < < < < < < < < < < < < < < < < < < < | > | 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 | ** the database file. ** ** 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 = SQLITE_OK; /* Return code */ /* This function is only called for rollback pagers in WRITER_DBMOD state. */ assert( !pagerUseWal(pPager) ); assert( pPager->eState==PAGER_WRITER_DBMOD ); assert( pPager->eLock==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) ){ assert( pPager->tempFile && rc==SQLITE_OK ); rc = pagerOpentemp(pPager, pPager->fd, pPager->vfsFlags); } /* Before the first write, give the VFS a hint of what the final ** file size will be. */ assert( rc!=SQLITE_OK || isOpen(pPager->fd) ); if( rc==SQLITE_OK && pPager->dbSize>pPager->dbHintSize ){ sqlite3_int64 szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize; sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile); pPager->dbHintSize = pPager->dbSize; } while( rc==SQLITE_OK && pList ){ Pgno pgno = pList->pgno; /* If there are dirty pages in the page cache with page numbers greater ** than Pager.dbSize, this means sqlite3PagerTruncateImage() was called to |
︙ | ︙ | |||
4058 4059 4060 4061 4062 4063 4064 | } if( rc==SQLITE_OK ){ rc = pagerWalFrames(pPager, pPg, 0, 0, 0); } }else{ /* Sync the journal file if required. */ | | > > | 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 | } if( rc==SQLITE_OK ){ rc = pagerWalFrames(pPager, pPg, 0, 0, 0); } }else{ /* Sync the journal file if required. */ if( pPg->flags&PGHDR_NEED_SYNC || pPager->eState==PAGER_WRITER_CACHEMOD ){ rc = syncJournal(pPager, 1); } /* If the page number of this page is larger than the current size of ** the database image, it may need to be written to the sub-journal. ** This is because the call to pager_write_pagelist() below will not ** actually write data to the file in this case. |
︙ | ︙ | |||
5120 5121 5122 5123 5124 5125 5126 | ** 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; | > | > | 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 | ** 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->dbHintSize = pPager->dbSize; pPager->dbFileSize = pPager->dbSize; 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) ); } |
︙ | ︙ |