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Overview
Comment: | Simplifications and performance improvement in pager_write(). |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
ab7aeeead395a05b91a921ef9ebe9252 |
User & Date: | drh 2015-06-29 14:11:50.755 |
Context
2015-06-29
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15:41 | Fix minor problems in the ota demo application. (check-in: 6aaaec6e63 user: dan tags: trunk) | |
14:11 | Simplifications and performance improvement in pager_write(). (check-in: ab7aeeead3 user: drh tags: trunk) | |
04:21 | Add the new PGHDR_CLEAN bit to PgHdr.flags in pcache.c. This bit is always the opposite of PGHDR_DIRTY. Use the extra bit to avoid a comparison for a small performance boost. (check-in: 8619fc346d user: drh tags: trunk) | |
Changes
Changes to src/bitvec.c.
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122 123 124 125 126 127 128 | } /* ** Check to see if the i-th bit is set. Return true or false. ** If p is NULL (if the bitmap has not been created) or if ** i is out of range, then return false. */ | | | | 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | } /* ** Check to see if the i-th bit is set. Return true or false. ** If p is NULL (if the bitmap has not been created) or if ** i is out of range, then return false. */ int sqlite3BitvecTestNotNull(Bitvec *p, u32 i){ assert( p!=0 ); i--; if( i>=p->iSize ) return 0; while( p->iDivisor ){ u32 bin = i/p->iDivisor; i = i%p->iDivisor; p = p->u.apSub[bin]; if (!p) { |
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145 146 147 148 149 150 151 152 153 154 155 156 157 158 | while( p->u.aHash[h] ){ if( p->u.aHash[h]==i ) return 1; h = (h+1) % BITVEC_NINT; } return 0; } } /* ** Set the i-th bit. Return 0 on success and an error code if ** anything goes wrong. ** ** This routine might cause sub-bitmaps to be allocated. Failing ** to get the memory needed to hold the sub-bitmap is the only | > > > | 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 | while( p->u.aHash[h] ){ if( p->u.aHash[h]==i ) return 1; h = (h+1) % BITVEC_NINT; } return 0; } } int sqlite3BitvecTest(Bitvec *p, u32 i){ return p!=0 && sqlite3BitvecTestNotNull(p,i); } /* ** Set the i-th bit. Return 0 on success and an error code if ** anything goes wrong. ** ** This routine might cause sub-bitmaps to be allocated. Failing ** to get the memory needed to hold the sub-bitmap is the only |
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Changes to src/pager.c.
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804 805 806 807 808 809 810 | ** ** if( isOpen(pPager->jfd) ){ ... ** ** instead of ** ** if( pPager->jfd->pMethods ){ ... */ | | | 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 | ** ** if( isOpen(pPager->jfd) ){ ... ** ** instead of ** ** if( pPager->jfd->pMethods ){ ... */ #define isOpen(pFd) ((pFd)->pMethods!=0) /* ** Return true if this pager uses a write-ahead log instead of the usual ** rollback journal. Otherwise false. */ #ifndef SQLITE_OMIT_WAL static int pagerUseWal(Pager *pPager){ |
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1027 1028 1029 1030 1031 1032 1033 | static int subjRequiresPage(PgHdr *pPg){ Pager *pPager = pPg->pPager; PagerSavepoint *p; Pgno pgno = pPg->pgno; int i; for(i=0; i<pPager->nSavepoint; i++){ p = &pPager->aSavepoint[i]; | | > > | 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 | static int subjRequiresPage(PgHdr *pPg){ Pager *pPager = pPg->pPager; PagerSavepoint *p; Pgno pgno = pPg->pgno; int i; for(i=0; i<pPager->nSavepoint; i++){ p = &pPager->aSavepoint[i]; if( p->nOrig>=pgno && 0==sqlite3BitvecTestNotNull(p->pInSavepoint, pgno) ){ return 1; } } return 0; } #ifdef SQLITE_DEBUG /* ** Return true if the page is already in the journal file. */ static int pageInJournal(Pager *pPager, PgHdr *pPg){ return sqlite3BitvecTest(pPager->pInJournal, pPg->pgno); } #endif /* ** Read a 32-bit integer from the given file descriptor. Store the integer ** that is read in *pRes. Return SQLITE_OK if everything worked, or an ** error code is something goes wrong. ** ** All values are stored on disk as big-endian. |
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5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 | assert( rc!=SQLITE_OK || pPager->eState==PAGER_WRITER_LOCKED ); assert( assert_pager_state(pPager) ); } PAGERTRACE(("TRANSACTION %d\n", PAGERID(pPager))); return rc; } /* ** Mark a single data page as writeable. The page is written into the ** main journal or sub-journal as required. If the page is written into ** one of the journals, the corresponding bit is set in the ** Pager.pInJournal bitvec and the PagerSavepoint.pInSavepoint bitvecs ** of any open savepoints as appropriate. */ static int pager_write(PgHdr *pPg){ Pager *pPager = pPg->pPager; int rc = SQLITE_OK; | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > < < | < < < < < < | < < < < < < < < < < | < < < < | < < < | < < < < < < | < | < < < < < < | < < < < | < | | | | < < < < | < | | | | | | | | | | | | | < < | | | | | < | < | 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662 5663 5664 5665 5666 5667 5668 5669 5670 5671 5672 5673 5674 5675 5676 5677 5678 5679 5680 5681 5682 5683 5684 5685 5686 5687 5688 5689 5690 5691 5692 5693 5694 5695 5696 5697 5698 5699 5700 5701 5702 5703 5704 5705 5706 5707 5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 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 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768 5769 5770 5771 5772 5773 5774 5775 5776 5777 5778 5779 5780 5781 5782 5783 5784 5785 5786 5787 | assert( rc!=SQLITE_OK || pPager->eState==PAGER_WRITER_LOCKED ); assert( assert_pager_state(pPager) ); } PAGERTRACE(("TRANSACTION %d\n", PAGERID(pPager))); return rc; } /* ** Write page pPg onto the end of the rollback journal. */ static SQLITE_NOINLINE int pagerAddPageToRollbackJournal(PgHdr *pPg){ Pager *pPager = pPg->pPager; int rc; u32 cksum; char *pData2; i64 iOff = pPager->journalOff; /* We should never write to the journal file the page that ** contains the database locks. The following assert verifies ** that we do not. */ assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) ); assert( pPager->journalHdr<=pPager->journalOff ); CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2); cksum = pager_cksum(pPager, (u8*)pData2); /* Even if an IO or diskfull error occurs while journalling the ** page in the block above, set the need-sync flag for the page. ** Otherwise, when the transaction is rolled back, the logic in ** playback_one_page() will think that the page needs to be restored ** in the database file. And if an IO error occurs while doing so, ** then corruption may follow. */ pPg->flags |= PGHDR_NEED_SYNC; rc = write32bits(pPager->jfd, iOff, pPg->pgno); if( rc!=SQLITE_OK ) return rc; rc = sqlite3OsWrite(pPager->jfd, pData2, pPager->pageSize, iOff+4); if( rc!=SQLITE_OK ) return rc; rc = write32bits(pPager->jfd, iOff+pPager->pageSize+4, cksum); if( rc!=SQLITE_OK ) return rc; IOTRACE(("JOUT %p %d %lld %d\n", pPager, pPg->pgno, pPager->journalOff, pPager->pageSize)); PAGER_INCR(sqlite3_pager_writej_count); PAGERTRACE(("JOURNAL %d page %d needSync=%d hash(%08x)\n", PAGERID(pPager), pPg->pgno, ((pPg->flags&PGHDR_NEED_SYNC)?1:0), pager_pagehash(pPg))); pPager->journalOff += 8 + pPager->pageSize; pPager->nRec++; assert( pPager->pInJournal!=0 ); rc = sqlite3BitvecSet(pPager->pInJournal, pPg->pgno); testcase( rc==SQLITE_NOMEM ); assert( rc==SQLITE_OK || rc==SQLITE_NOMEM ); rc |= addToSavepointBitvecs(pPager, pPg->pgno); assert( rc==SQLITE_OK || rc==SQLITE_NOMEM ); return rc; } /* ** Mark a single data page as writeable. The page is written into the ** main journal or sub-journal as required. If the page is written into ** one of the journals, the corresponding bit is set in the ** Pager.pInJournal bitvec and the PagerSavepoint.pInSavepoint bitvecs ** of any open savepoints as appropriate. */ static int pager_write(PgHdr *pPg){ 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) ); assert( pPager->errCode==0 ); assert( pPager->readOnly==0 ); CHECK_PAGE(pPg); /* The journal file needs to be opened. 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. ** ** This is done before calling sqlite3PcacheMakeDirty() on the page. ** Otherwise, if it were done after calling sqlite3PcacheMakeDirty(), then ** an error might occur and the pager would end up in WRITER_LOCKED state ** with pages marked as dirty in the cache. */ 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) ); /* Mark the page that is about to be modified as dirty. */ sqlite3PcacheMakeDirty(pPg); /* If a rollback journal is in use, them make sure the page that is about ** to change is in the rollback journal, or if the page is a new page off ** then end of the file, make sure it is marked as PGHDR_NEED_SYNC. */ assert( (pPager->pInJournal!=0) == isOpen(pPager->jfd) ); if( pPager->pInJournal!=0 /* Journal open */ && sqlite3BitvecTestNotNull(pPager->pInJournal, pPg->pgno)==0 /* pPg not in jrnl */ ){ assert( pagerUseWal(pPager)==0 ); if( pPg->pgno<=pPager->dbOrigSize ){ rc = pagerAddPageToRollbackJournal(pPg); if( rc!=SQLITE_OK ){ return rc; } }else{ if( pPager->eState!=PAGER_WRITER_DBMOD ){ pPg->flags |= PGHDR_NEED_SYNC; } PAGERTRACE(("APPEND %d page %d needSync=%d\n", PAGERID(pPager), pPg->pgno, ((pPg->flags&PGHDR_NEED_SYNC)?1:0))); } } /* If the statement journal is open and the page is not in it, ** then write the page into the statement journal. */ if( pPager->nSavepoint>0 && subjRequiresPage(pPg) ){ rc = subjournalPage(pPg); } /* Update the database size and return. */ if( pPager->dbSize<pPg->pgno ){ pPager->dbSize = pPg->pgno; } return rc; } /* |
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Changes to src/sqliteInt.h.
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3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 | # define sqlite3FaultSim(X) SQLITE_OK #else int sqlite3FaultSim(int); #endif Bitvec *sqlite3BitvecCreate(u32); int sqlite3BitvecTest(Bitvec*, u32); int sqlite3BitvecSet(Bitvec*, u32); void sqlite3BitvecClear(Bitvec*, u32, void*); void sqlite3BitvecDestroy(Bitvec*); u32 sqlite3BitvecSize(Bitvec*); #ifndef SQLITE_OMIT_BUILTIN_TEST int sqlite3BitvecBuiltinTest(int,int*); #endif | > | 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 | # define sqlite3FaultSim(X) SQLITE_OK #else int sqlite3FaultSim(int); #endif Bitvec *sqlite3BitvecCreate(u32); int sqlite3BitvecTest(Bitvec*, u32); int sqlite3BitvecTestNotNull(Bitvec*, u32); int sqlite3BitvecSet(Bitvec*, u32); void sqlite3BitvecClear(Bitvec*, u32, void*); void sqlite3BitvecDestroy(Bitvec*); u32 sqlite3BitvecSize(Bitvec*); #ifndef SQLITE_OMIT_BUILTIN_TEST int sqlite3BitvecBuiltinTest(int,int*); #endif |
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