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Overview
Comment: | Create and use a new pager interface sqlite3PagerUnrefNotNull() that works just like sqlite3PagerUnref() but guarantees that its argument is not a NULL pointer. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
e00f37e2333cac5b53e17cf764ab56c4 |
User & Date: | drh 2013-12-13 19:35:21.600 |
Context
2013-12-13
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19:48 | Reduce the number of calls to the subjRequiresPage() routine inside of pager. (check-in: e50ff39a93 user: drh tags: trunk) | |
19:35 | Create and use a new pager interface sqlite3PagerUnrefNotNull() that works just like sqlite3PagerUnref() but guarantees that its argument is not a NULL pointer. (check-in: e00f37e233 user: drh tags: trunk) | |
18:50 | Enhance the pcache1PinPage() routine so that it called much less often and runs much faster in the cases when it is actually called. (check-in: a845779cd3 user: drh tags: trunk) | |
Changes
Changes to src/btree.c.
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1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 | ** Release a MemPage. This should be called once for each prior ** call to btreeGetPage. */ static void releasePage(MemPage *pPage){ if( pPage ){ assert( pPage->aData ); assert( pPage->pBt ); assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage ); assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData ); assert( sqlite3_mutex_held(pPage->pBt->mutex) ); | > | | 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 | ** Release a MemPage. This should be called once for each prior ** call to btreeGetPage. */ static void releasePage(MemPage *pPage){ if( pPage ){ assert( pPage->aData ); assert( pPage->pBt ); assert( pPage->pDbPage!=0 ); assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage ); assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData ); assert( sqlite3_mutex_held(pPage->pBt->mutex) ); sqlite3PagerUnrefNotNull(pPage->pDbPage); } } /* ** During a rollback, when the pager reloads information into the cache ** so that the cache is restored to its original state at the start of ** the transaction, for each page restored this routine is called. |
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Changes to src/pager.c.
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1986 1987 1988 1989 1990 1991 1992 | #ifdef SQLITE_CHECK_PAGES sqlite3PcacheIterateDirty(pPager->pPCache, pager_set_pagehash); if( pPager->dbSize==0 && sqlite3PcacheRefCount(pPager->pPCache)>0 ){ PgHdr *p = pager_lookup(pPager, 1); if( p ){ p->pageHash = 0; | | | 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 | #ifdef SQLITE_CHECK_PAGES sqlite3PcacheIterateDirty(pPager->pPCache, pager_set_pagehash); if( pPager->dbSize==0 && sqlite3PcacheRefCount(pPager->pPCache)>0 ){ PgHdr *p = pager_lookup(pPager, 1); if( p ){ p->pageHash = 0; sqlite3PagerUnrefNotNull(p); } } #endif sqlite3BitvecDestroy(pPager->pInJournal); pPager->pInJournal = 0; pPager->nRec = 0; |
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2979 2980 2981 2982 2983 2984 2985 | rc = sqlite3WalFindFrame(pPager->pWal, pPg->pgno, &iFrame); if( rc==SQLITE_OK ){ rc = readDbPage(pPg, iFrame); } if( rc==SQLITE_OK ){ pPager->xReiniter(pPg); } | | | 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 | rc = sqlite3WalFindFrame(pPager->pWal, pPg->pgno, &iFrame); if( rc==SQLITE_OK ){ rc = readDbPage(pPg, iFrame); } if( rc==SQLITE_OK ){ pPager->xReiniter(pPg); } sqlite3PagerUnrefNotNull(pPg); } } /* Normally, if a transaction is rolled back, any backup processes are ** updated as data is copied out of the rollback journal and into the ** database. This is not generally possible with a WAL database, as ** rollback involves simply truncating the log file. Therefore, if one |
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5435 5436 5437 5438 5439 5440 5441 | ** Release a page reference. ** ** If the number of references to the page drop to zero, then the ** page is added to the LRU list. When all references to all pages ** are released, a rollback occurs and the lock on the database is ** removed. */ | | > | | | | | | | | | > > | 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456 5457 5458 5459 5460 5461 | ** Release a page reference. ** ** If the number of references to the page drop to zero, then the ** page is added to the LRU list. When all references to all pages ** are released, a rollback occurs and the lock on the database is ** removed. */ void sqlite3PagerUnrefNotNull(DbPage *pPg){ Pager *pPager; assert( pPg!=0 ); pPager = pPg->pPager; if( pPg->flags & PGHDR_MMAP ){ pagerReleaseMapPage(pPg); }else{ sqlite3PcacheRelease(pPg); } pagerUnlockIfUnused(pPager); } void sqlite3PagerUnref(DbPage *pPg){ if( pPg ) sqlite3PagerUnrefNotNull(pPg); } /* ** This function is called at the start of every write transaction. ** There must already be a RESERVED or EXCLUSIVE lock on the database ** file when this routine is called. ** |
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5826 5827 5828 5829 5830 5831 5832 | if( pg!=PAGER_MJ_PGNO(pPager) ){ rc = sqlite3PagerGet(pPager, pg, &pPage); if( rc==SQLITE_OK ){ rc = pager_write(pPage); if( pPage->flags&PGHDR_NEED_SYNC ){ needSync = 1; } | | | | | 5829 5830 5831 5832 5833 5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 5862 5863 5864 5865 5866 | if( pg!=PAGER_MJ_PGNO(pPager) ){ rc = sqlite3PagerGet(pPager, pg, &pPage); if( rc==SQLITE_OK ){ rc = pager_write(pPage); if( pPage->flags&PGHDR_NEED_SYNC ){ needSync = 1; } sqlite3PagerUnrefNotNull(pPage); } } }else if( (pPage = pager_lookup(pPager, pg))!=0 ){ if( pPage->flags&PGHDR_NEED_SYNC ){ needSync = 1; } sqlite3PagerUnrefNotNull(pPage); } } /* If the PGHDR_NEED_SYNC flag is set for any of the nPage pages ** starting at pg1, then it needs to be set for all of them. Because ** writing to any of these nPage pages may damage the others, the ** journal file must contain sync()ed copies of all of them ** before any of them can be written out to the database file. */ if( rc==SQLITE_OK && needSync ){ assert( !MEMDB ); for(ii=0; ii<nPage; ii++){ PgHdr *pPage = pager_lookup(pPager, pg1+ii); if( pPage ){ pPage->flags |= PGHDR_NEED_SYNC; sqlite3PagerUnrefNotNull(pPage); } } } assert( (pPager->doNotSpill & SPILLFLAG_NOSYNC)!=0 ); pPager->doNotSpill &= ~SPILLFLAG_NOSYNC; }else{ |
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6779 6780 6781 6782 6783 6784 6785 | /* For an in-memory database, make sure the original page continues ** to exist, in case the transaction needs to roll back. Use pPgOld ** as the original page since it has already been allocated. */ if( MEMDB ){ assert( pPgOld ); sqlite3PcacheMove(pPgOld, origPgno); | | | 6782 6783 6784 6785 6786 6787 6788 6789 6790 6791 6792 6793 6794 6795 6796 | /* For an in-memory database, make sure the original page continues ** to exist, in case the transaction needs to roll back. Use pPgOld ** as the original page since it has already been allocated. */ if( MEMDB ){ assert( pPgOld ); sqlite3PcacheMove(pPgOld, origPgno); sqlite3PagerUnrefNotNull(pPgOld); } if( needSyncPgno ){ /* If needSyncPgno is non-zero, then the journal file needs to be ** sync()ed before any data is written to database file page needSyncPgno. ** Currently, no such page exists in the page-cache and the ** "is journaled" bitvec flag has been set. This needs to be remedied by |
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6808 6809 6810 6811 6812 6813 6814 | assert( pPager->pTmpSpace!=0 ); sqlite3BitvecClear(pPager->pInJournal, needSyncPgno, pPager->pTmpSpace); } return rc; } pPgHdr->flags |= PGHDR_NEED_SYNC; sqlite3PcacheMakeDirty(pPgHdr); | | | 6811 6812 6813 6814 6815 6816 6817 6818 6819 6820 6821 6822 6823 6824 6825 | assert( pPager->pTmpSpace!=0 ); sqlite3BitvecClear(pPager->pInJournal, needSyncPgno, pPager->pTmpSpace); } return rc; } pPgHdr->flags |= PGHDR_NEED_SYNC; sqlite3PcacheMakeDirty(pPgHdr); sqlite3PagerUnrefNotNull(pPgHdr); } return SQLITE_OK; } #endif /* |
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Changes to src/pager.h.
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132 133 134 135 136 137 138 139 140 141 142 143 144 145 | /* Functions used to obtain and release page references. */ int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag); #define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0) DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno); void sqlite3PagerRef(DbPage*); void sqlite3PagerUnref(DbPage*); /* Operations on page references. */ int sqlite3PagerWrite(DbPage*); void sqlite3PagerDontWrite(DbPage*); int sqlite3PagerMovepage(Pager*,DbPage*,Pgno,int); int sqlite3PagerPageRefcount(DbPage*); void *sqlite3PagerGetData(DbPage *); | > | 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 | /* Functions used to obtain and release page references. */ int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag); #define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0) DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno); void sqlite3PagerRef(DbPage*); void sqlite3PagerUnref(DbPage*); void sqlite3PagerUnrefNotNull(DbPage*); /* Operations on page references. */ int sqlite3PagerWrite(DbPage*); void sqlite3PagerDontWrite(DbPage*); int sqlite3PagerMovepage(Pager*,DbPage*,Pgno,int); int sqlite3PagerPageRefcount(DbPage*); void *sqlite3PagerGetData(DbPage *); |
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