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Overview
Comment: | Minor change to wal.c on this branch to make it more similar to trunk. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | begin-concurrent |
Files: | files | file ages | folders |
SHA3-256: |
6a7af3ead5949c461430c1fa92798dc2 |
User & Date: | dan 2018-12-03 20:38:15.728 |
Context
2018-12-04
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13:51 | Fix a problem with SQLITE_ENABLE_EXPENSIVE_ASSERT builds on this branch. (check-in: ddb4a6fbf8 user: dan tags: begin-concurrent) | |
2018-12-03
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20:49 | Merge the wal2 and begin-concurrent code. Both features work, but not at the same time. (check-in: b7281a1caa user: dan tags: begin-concurrent-wal2) | |
20:38 | Minor change to wal.c on this branch to make it more similar to trunk. (check-in: 6a7af3ead5 user: dan tags: begin-concurrent) | |
19:29 | Cherrypick a couple of fixes from begin-concurrent-pnu into this branch. The differences between the two branches are now that this one does not have "PRAGMA noop_update" or the mutex-free PRNG. (check-in: a56506b938 user: dan tags: begin-concurrent) | |
Changes
Changes to src/wal.c.
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2850 2851 2852 2853 2854 2855 2856 | if( pWal->readLock>=0 ){ walUnlockShared(pWal, WAL_READ_LOCK(pWal->readLock)); pWal->readLock = -1; } } /* | | | > > > > | | | < | > > < > > > > > > > > > > > > > > | 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 | if( pWal->readLock>=0 ){ walUnlockShared(pWal, WAL_READ_LOCK(pWal->readLock)); pWal->readLock = -1; } } /* ** Search the wal file for page pgno. If found, set *piRead to the frame that ** contains the page. Otherwise, if pgno is not in the wal file, set *piRead ** to zero. ** ** Return SQLITE_OK if successful, or an error code if an error occurs. If an ** error does occur, the final value of *piRead is undefined. */ int sqlite3WalFindFrame( Wal *pWal, /* WAL handle */ Pgno pgno, /* Database page number to read data for */ u32 *piRead /* OUT: Frame number (or zero) */ ){ u32 iRead = 0; /* If !=0, WAL frame to return data from */ u32 iLast = pWal->hdr.mxFrame; /* Last page in WAL for this reader */ int iHash; /* Used to loop through N hash tables */ int iMinHash; /* This routine is only be called from within a read transaction. */ assert( pWal->readLock>=0 || pWal->lockError ); /* If the "last page" field of the wal-index header snapshot is 0, then ** no data will be read from the wal under any circumstances. Return early ** in this case as an optimization. Likewise, if pWal->readLock==0, ** then the WAL is ignored by the reader so return early, as if the ** WAL were empty. */ if( iLast==0 || (pWal->readLock==0 && pWal->bShmUnreliable==0) ){ *piRead = 0; return SQLITE_OK; } /* Each iteration of the following for() loop searches one ** hash table (each hash table indexes up to HASHTABLE_NPAGE frames). ** ** This code might run concurrently to the code in walIndexAppend() ** that adds entries to the wal-index (and possibly to this hash ** table). This means the value just read from the hash |
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2913 2914 2915 2916 2917 2918 2919 | if( (nCollide--)==0 ){ return SQLITE_CORRUPT_BKPT; } } if( iRead ) break; } | < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < | | 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 | if( (nCollide--)==0 ){ return SQLITE_CORRUPT_BKPT; } } if( iRead ) break; } #ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT /* If expensive assert() statements are available, do a linear search ** of the wal-index file content. Make sure the results agree with the ** result obtained using the hash indexes above. */ if( rc==SQLITE_OK ){ u32 iRead2 = 0; u32 iTest; assert( pWal->bShmUnreliable || pWal->minFrame>0 ); for(iTest=iLast; iTest>=pWal->minFrame && iTest>0; iTest--){ if( walFramePgno(pWal, iTest)==pgno ){ iRead2 = iTest; break; } } assert( iRead==iRead2 ); } #endif *piRead = iRead; return SQLITE_OK; } /* ** Read the contents of frame iRead from the wal file into buffer pOut ** (which is nOut bytes in size). Return SQLITE_OK if successful, or an ** error code otherwise. */ |
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