SQLite

Check-in [5a4013ec9c]
Login

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

Overview
Comment:Correct use of usableSize versus pageSize in btree.c. Ticket #1010. (CVS 2125)
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 5a4013ec9cabb2c933cbf45495f5d1e8b3b20da5
User & Date: drh 2004-11-20 20:31:12.000
Context
2004-11-20
20:44
Avoid excess heap usage when copying expressions. Ticket #979. (CVS 2127) (check-in: d10560c752 user: drh tags: trunk)
20:31
Correct use of usableSize versus pageSize in btree.c. Ticket #1010. (CVS 2125) (check-in: 5a4013ec9c user: drh tags: trunk)
20:18
Better error message on an SQLITE_RANGE error. Ticket #991. (CVS 2124) (check-in: accd432e4d user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/btree.c.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.220 2004/11/17 10:22:03 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.











|







1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.221 2004/11/20 20:31:12 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
** TODO: This macro is very similary to PAGER_MJ_PGNO() in pager.c. They
** should possibly be consolidated (presumably in pager.h).
*/
#define PENDING_BYTE_PAGE(pBt) ((PENDING_BYTE/(pBt)->pageSize)+1)

#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** These two macros define the location of the pointer-map entry for a 
** database page. The first argument to each is the page size used 
** by the database (often 1024). The second is the page number to look
** up in the pointer map.
**
** PTRMAP_PAGENO returns the database page number of the pointer-map
** page that stores the required pointer. PTRMAP_PTROFFSET returns
** the offset of the requested map entry.
**
** If the pgno argument passed to PTRMAP_PAGENO is a pointer-map page,
** then pgno is returned. So (pgno==PTRMAP_PAGENO(pgsz, pgno)) can be







|
|
|
|







409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
** TODO: This macro is very similary to PAGER_MJ_PGNO() in pager.c. They
** should possibly be consolidated (presumably in pager.h).
*/
#define PENDING_BYTE_PAGE(pBt) ((PENDING_BYTE/(pBt)->pageSize)+1)

#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** These macros define the location of the pointer-map entry for a 
** database page. The first argument to each is the number of usable
** bytes on each page of the database (often 1024). The second is the
** page number to look up in the pointer map.
**
** PTRMAP_PAGENO returns the database page number of the pointer-map
** page that stores the required pointer. PTRMAP_PTROFFSET returns
** the offset of the requested map entry.
**
** If the pgno argument passed to PTRMAP_PAGENO is a pointer-map page,
** then pgno is returned. So (pgno==PTRMAP_PAGENO(pgsz, pgno)) can be
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno pgno){
  u8 *pPtrmap;    /* The pointer map page */
  Pgno iPtrmap;   /* The pointer map page number */
  int offset;     /* Offset in pointer map page */
  int rc;

  assert( key!=0 );
  iPtrmap = PTRMAP_PAGENO(pBt->pageSize, key);
  rc = sqlite3pager_get(pBt->pPager, iPtrmap, (void **)&pPtrmap);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  offset = PTRMAP_PTROFFSET(pBt->pageSize, key);

  if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=pgno ){
    rc = sqlite3pager_write(pPtrmap);
    if( rc!=0 ){
      return rc;
    }
    pPtrmap[offset] = eType;







|




|







472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno pgno){
  u8 *pPtrmap;    /* The pointer map page */
  Pgno iPtrmap;   /* The pointer map page number */
  int offset;     /* Offset in pointer map page */
  int rc;

  assert( key!=0 );
  iPtrmap = PTRMAP_PAGENO(pBt->usableSize, key);
  rc = sqlite3pager_get(pBt->pPager, iPtrmap, (void **)&pPtrmap);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  offset = PTRMAP_PTROFFSET(pBt->usableSize, key);

  if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=pgno ){
    rc = sqlite3pager_write(pPtrmap);
    if( rc!=0 ){
      return rc;
    }
    pPtrmap[offset] = eType;
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
*/
static int ptrmapGet(Btree *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
  int iPtrmap;       /* Pointer map page index */
  u8 *pPtrmap;       /* Pointer map page data */
  int offset;        /* Offset of entry in pointer map */
  int rc;

  iPtrmap = PTRMAP_PAGENO(pBt->pageSize, key);
  rc = sqlite3pager_get(pBt->pPager, iPtrmap, (void **)&pPtrmap);
  if( rc!=0 ){
    return rc;
  }

  offset = PTRMAP_PTROFFSET(pBt->pageSize, key);
  if( pEType ) *pEType = pPtrmap[offset];
  if( pPgno ) *pPgno = get4byte(&pPtrmap[offset+1]);

  sqlite3pager_unref(pPtrmap);
  return SQLITE_OK;
}








|





|







505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
*/
static int ptrmapGet(Btree *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
  int iPtrmap;       /* Pointer map page index */
  u8 *pPtrmap;       /* Pointer map page data */
  int offset;        /* Offset of entry in pointer map */
  int rc;

  iPtrmap = PTRMAP_PAGENO(pBt->usableSize, key);
  rc = sqlite3pager_get(pBt->pPager, iPtrmap, (void **)&pPtrmap);
  if( rc!=0 ){
    return rc;
  }

  offset = PTRMAP_PTROFFSET(pBt->usableSize, key);
  if( pEType ) *pEType = pPtrmap[offset];
  if( pPgno ) *pPgno = get4byte(&pPtrmap[offset+1]);

  sqlite3pager_unref(pPtrmap);
  return SQLITE_OK;
}

1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
  }

  origSize = sqlite3pager_pagecount(pPager);
  nPtrMap = (nFreeList-origSize+PTRMAP_PAGENO(pgsz, origSize)+pgsz/5)/(pgsz/5);
  finSize = origSize - nFreeList - nPtrMap;
  if( origSize>PENDING_BYTE_PAGE(pBt) && finSize<=PENDING_BYTE_PAGE(pBt) ){
    finSize--;
    if( PTRMAP_ISPAGE(pBt->pageSize, finSize) ){
      finSize--;
    }
  }
  TRACE(("AUTOVACUUM: Begin (db size %d->%d)\n", origSize, finSize));

  /* Variable 'finSize' will be the size of the file in pages after
  ** the auto-vacuum has completed (the current file size minus the number







|







1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
  }

  origSize = sqlite3pager_pagecount(pPager);
  nPtrMap = (nFreeList-origSize+PTRMAP_PAGENO(pgsz, origSize)+pgsz/5)/(pgsz/5);
  finSize = origSize - nFreeList - nPtrMap;
  if( origSize>PENDING_BYTE_PAGE(pBt) && finSize<=PENDING_BYTE_PAGE(pBt) ){
    finSize--;
    if( PTRMAP_ISPAGE(pBt->usableSize, finSize) ){
      finSize--;
    }
  }
  TRACE(("AUTOVACUUM: Begin (db size %d->%d)\n", origSize, finSize));

  /* Variable 'finSize' will be the size of the file in pages after
  ** the auto-vacuum has completed (the current file size minus the number
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
    releasePage(pTrunk);
  }else{
    /* There are no pages on the freelist, so create a new page at the
    ** end of the file */
    *pPgno = sqlite3pager_pagecount(pBt->pPager) + 1;

#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum && PTRMAP_ISPAGE(pBt->pageSize, *pPgno) ){
      /* If *pPgno refers to a pointer-map page, allocate two new pages
      ** at the end of the file instead of one. The first allocated page
      ** becomes a new pointer-map page, the second is used by the caller.
      */
      TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", *pPgno));
      assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
      (*pPgno)++;







|







3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
    releasePage(pTrunk);
  }else{
    /* There are no pages on the freelist, so create a new page at the
    ** end of the file */
    *pPgno = sqlite3pager_pagecount(pBt->pPager) + 1;

#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum && PTRMAP_ISPAGE(pBt->usableSize, *pPgno) ){
      /* If *pPgno refers to a pointer-map page, allocate two new pages
      ** at the end of the file instead of one. The first allocated page
      ** becomes a new pointer-map page, the second is used by the caller.
      */
      TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", *pPgno));
      assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
      (*pPgno)++;
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
    rc = sqlite3BtreeGetMeta(pBt, 4, &pgnoRoot);
    if( rc!=SQLITE_OK ) return rc;
    pgnoRoot++;

    /* The new root-page may not be allocated on a pointer-map page, or the
    ** PENDING_BYTE page.
    */
    if( pgnoRoot==PTRMAP_PAGENO(pBt->pageSize, pgnoRoot) ||
        pgnoRoot==PENDING_BYTE_PAGE(pBt) ){
      pgnoRoot++;
    }
    assert( pgnoRoot>=3 );

    /* Allocate a page. The page that currently resides at pgnoRoot will
    ** be moved to the allocated page (unless the allocated page happens







|







4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
    rc = sqlite3BtreeGetMeta(pBt, 4, &pgnoRoot);
    if( rc!=SQLITE_OK ) return rc;
    pgnoRoot++;

    /* The new root-page may not be allocated on a pointer-map page, or the
    ** PENDING_BYTE page.
    */
    if( pgnoRoot==PTRMAP_PAGENO(pBt->usableSize, pgnoRoot) ||
        pgnoRoot==PENDING_BYTE_PAGE(pBt) ){
      pgnoRoot++;
    }
    assert( pgnoRoot>=3 );

    /* Allocate a page. The page that currently resides at pgnoRoot will
    ** be moved to the allocated page (unless the allocated page happens
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
      ** be a root-page number, less one again if that is the
      ** PENDING_BYTE_PAGE.
      */
      maxRootPgno--;
      if( maxRootPgno==PENDING_BYTE_PAGE(pBt) ){
        maxRootPgno--;
      }
      if( maxRootPgno==PTRMAP_PAGENO(pBt->pageSize, maxRootPgno) ){
        maxRootPgno--;
      }
      assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );

      rc = sqlite3BtreeUpdateMeta(pBt, 4, maxRootPgno);
    }else{
      rc = freePage(pPage);







|







4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
      ** be a root-page number, less one again if that is the
      ** PENDING_BYTE_PAGE.
      */
      maxRootPgno--;
      if( maxRootPgno==PENDING_BYTE_PAGE(pBt) ){
        maxRootPgno--;
      }
      if( maxRootPgno==PTRMAP_PAGENO(pBt->usableSize, maxRootPgno) ){
        maxRootPgno--;
      }
      assert( maxRootPgno!=PENDING_BYTE_PAGE(pBt) );

      rc = sqlite3BtreeUpdateMeta(pBt, 4, maxRootPgno);
    }else{
      rc = freePage(pPage);
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
  sCheck.nPage = sqlite3pager_pagecount(sCheck.pPager);
  if( sCheck.nPage==0 ){
    unlockBtreeIfUnused(pBt);
    return 0;
  }
  sCheck.anRef = sqliteMallocRaw( (sCheck.nPage+1)*sizeof(sCheck.anRef[0]) );
  for(i=0; i<=sCheck.nPage; i++){ sCheck.anRef[i] = 0; }
  i = PENDING_BYTE/pBt->pageSize + 1;
  if( i<=sCheck.nPage ){
    sCheck.anRef[i] = 1;
  }
  sCheck.zErrMsg = 0;

  /* Check the integrity of the freelist
  */







|







5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
  sCheck.nPage = sqlite3pager_pagecount(sCheck.pPager);
  if( sCheck.nPage==0 ){
    unlockBtreeIfUnused(pBt);
    return 0;
  }
  sCheck.anRef = sqliteMallocRaw( (sCheck.nPage+1)*sizeof(sCheck.anRef[0]) );
  for(i=0; i<=sCheck.nPage; i++){ sCheck.anRef[i] = 0; }
  i = PENDING_BYTE_PAGE(pBt);
  if( i<=sCheck.nPage ){
    sCheck.anRef[i] = 1;
  }
  sCheck.zErrMsg = 0;

  /* Check the integrity of the freelist
  */
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
    }
#else
    /* If the database supports auto-vacuum, make sure no tables contain
    ** references to pointer-map pages.
    */
    if( sCheck.anRef[i]==0 && 
       (PTRMAP_PAGENO(pBt->pageSize, i)!=i || !pBt->autoVacuum) ){
      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
    }
    if( sCheck.anRef[i]!=0 && 
       (PTRMAP_PAGENO(pBt->pageSize, i)==i && pBt->autoVacuum) ){
      checkAppendMsg(&sCheck, 0, "Pointer map page %d is referenced", i);
    }
#endif
  }

  /* Make sure this analysis did not leave any unref() pages
  */







|



|







5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
    }
#else
    /* If the database supports auto-vacuum, make sure no tables contain
    ** references to pointer-map pages.
    */
    if( sCheck.anRef[i]==0 && 
       (PTRMAP_PAGENO(pBt->usableSize, i)!=i || !pBt->autoVacuum) ){
      checkAppendMsg(&sCheck, 0, "Page %d is never used", i);
    }
    if( sCheck.anRef[i]!=0 && 
       (PTRMAP_PAGENO(pBt->usableSize, i)==i && pBt->autoVacuum) ){
      checkAppendMsg(&sCheck, 0, "Pointer map page %d is referenced", i);
    }
#endif
  }

  /* Make sure this analysis did not leave any unref() pages
  */