SQLite

Check-in [f9863b39d9]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Tweak the code on this branch to detect b-tree page corruption in the same cases as the trunk.
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | defragmentpage-opt
Files: files | file ages | folders
SHA1: f9863b39d96dce6cb5e49a5f3a445ff3d897a951
User & Date: dan 2017-02-25 16:24:02.032
Context
2017-02-25
17:47
Optimize defragmentPage() in the case where the page contains either one or two free-blocks and a small number of fragmented bytes. (check-in: 4cd2a9672c user: dan tags: trunk)
16:24
Tweak the code on this branch to detect b-tree page corruption in the same cases as the trunk. (Closed-Leaf check-in: f9863b39d9 user: dan tags: defragmentpage-opt)
2017-02-24
19:58
Optimize defragmentPage() in the case where the page contains either one or two free-blocks and a small number of fragmented bytes. (check-in: 202b1c0276 user: dan tags: defragmentpage-opt)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/btree.c.
1421
1422
1423
1424
1425
1426
1427


1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
      x = get2byte(&data[hdr+5]);
      memcpy(&temp[x], &data[x], (cbrk+size) - x);
      src = temp;
    }
    memcpy(&data[cbrk], &src[pc], size);
  }
  data[hdr+7] = 0;


  if( cbrk-iCellFirst!=pPage->nFree ){
    return SQLITE_CORRUPT_BKPT;
  }

 defragment_out:
  assert( cbrk>=iCellFirst );
  put2byte(&data[hdr+5], cbrk);
  data[hdr+1] = 0;
  data[hdr+2] = 0;
  memset(&data[iCellFirst], 0, cbrk-iCellFirst);
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  return SQLITE_OK;







>
>
|


<
<







1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432


1433
1434
1435
1436
1437
1438
1439
      x = get2byte(&data[hdr+5]);
      memcpy(&temp[x], &data[x], (cbrk+size) - x);
      src = temp;
    }
    memcpy(&data[cbrk], &src[pc], size);
  }
  data[hdr+7] = 0;

 defragment_out:
  if( data[hdr+7]+cbrk-iCellFirst!=pPage->nFree ){
    return SQLITE_CORRUPT_BKPT;
  }


  assert( cbrk>=iCellFirst );
  put2byte(&data[hdr+5], cbrk);
  data[hdr+1] = 0;
  data[hdr+2] = 0;
  memset(&data[iCellFirst], 0, cbrk-iCellFirst);
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  return SQLITE_OK;
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
  */
  testcase( gap+2+nByte==top );
  if( gap+2+nByte>top ){
    assert( pPage->nCell>0 || CORRUPT_DB );
    rc = defragmentPage(pPage, MIN(4, pPage->nFree - (2+nByte)));
    if( rc ) return rc;
    top = get2byteNotZero(&data[hdr+5]);
    assert( gap+nByte<=top );
  }


  /* Allocate memory from the gap in between the cell pointer array
  ** and the cell content area.  The btreeInitPage() call has already
  ** validated the freelist.  Given that the freelist is valid, there
  ** is no way that the allocation can extend off the end of the page.







|







1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
  */
  testcase( gap+2+nByte==top );
  if( gap+2+nByte>top ){
    assert( pPage->nCell>0 || CORRUPT_DB );
    rc = defragmentPage(pPage, MIN(4, pPage->nFree - (2+nByte)));
    if( rc ) return rc;
    top = get2byteNotZero(&data[hdr+5]);
    assert( gap+2+nByte<=top );
  }


  /* Allocate memory from the gap in between the cell pointer array
  ** and the cell content area.  The btreeInitPage() call has already
  ** validated the freelist.  Given that the freelist is valid, there
  ** is no way that the allocation can extend off the end of the page.
7721
7722
7723
7724
7725
7726
7727
7728
7729
7730
7731
7732
7733
7734
7735
    **
    ** It is critical that the child page be defragmented before being
    ** copied into the parent, because if the parent is page 1 then it will
    ** by smaller than the child due to the database header, and so all the
    ** free space needs to be up front.
    */
    assert( nNew==1 || CORRUPT_DB );
    rc = defragmentPage(apNew[0], 0);
    testcase( rc!=SQLITE_OK );
    assert( apNew[0]->nFree == 
        (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2)
      || rc!=SQLITE_OK
    );
    copyNodeContent(apNew[0], pParent, &rc);
    freePage(apNew[0], &rc);







|







7721
7722
7723
7724
7725
7726
7727
7728
7729
7730
7731
7732
7733
7734
7735
    **
    ** It is critical that the child page be defragmented before being
    ** copied into the parent, because if the parent is page 1 then it will
    ** by smaller than the child due to the database header, and so all the
    ** free space needs to be up front.
    */
    assert( nNew==1 || CORRUPT_DB );
    rc = defragmentPage(apNew[0], -1);
    testcase( rc!=SQLITE_OK );
    assert( apNew[0]->nFree == 
        (get2byte(&apNew[0]->aData[5])-apNew[0]->cellOffset-apNew[0]->nCell*2)
      || rc!=SQLITE_OK
    );
    copyNodeContent(apNew[0], pParent, &rc);
    freePage(apNew[0], &rc);