/ Check-in [da1cbfa7]
Login

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

Overview
Comment:Add explicit casts to silence nuisance warnings from VC++. (CVS 6004)
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: da1cbfa766f7f379c01f4ac9c1210462d8d7c590
User & Date: drh 2008-12-10 16:45:51
Context
2008-12-10
17:20
Remove or rename local variables that shadow other variables or parameters. (CVS 6005) check-in: e7e9fa4f user: drh tags: trunk
16:45
Add explicit casts to silence nuisance warnings from VC++. (CVS 6004) check-in: da1cbfa7 user: drh tags: trunk
11:49
Use memcpy() rather than "=" to copy a structure, in order to work around a bug in the XLC compiler on AIX. Ticket #3344. (CVS 6003) check-in: 18bbcafc user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/analyze.c.

7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
..
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
**    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.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.46 2008/11/19 16:52:44 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.
................................................................................
  int iDb,                /* The database we are looking in */
  int iStatCur,           /* Open the sqlite_stat1 table on this cursor */
  const char *zWhere      /* Delete entries associated with this table */
){
  sqlite3 *db = pParse->db;
  Db *pDb;
  int iRootPage;
  int createStat1 = 0;
  Table *pStat;
  Vdbe *v = sqlite3GetVdbe(pParse);

  if( v==0 ) return;
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  assert( sqlite3VdbeDb(v)==db );
  pDb = &db->aDb[iDb];







|







 







|







7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
..
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
**    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.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.47 2008/12/10 16:45:51 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.
................................................................................
  int iDb,                /* The database we are looking in */
  int iStatCur,           /* Open the sqlite_stat1 table on this cursor */
  const char *zWhere      /* Delete entries associated with this table */
){
  sqlite3 *db = pParse->db;
  Db *pDb;
  int iRootPage;
  u8 createStat1 = 0;
  Table *pStat;
  Vdbe *v = sqlite3GetVdbe(pParse);

  if( v==0 ) return;
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  assert( sqlite3VdbeDb(v)==db );
  pDb = &db->aDb[iDb];

Changes to src/attach.c.

7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
...
331
332
333
334
335
336
337

338
339
340
341
342
343
344
345
**    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.
**
*************************************************************************
** This file contains code used to implement the ATTACH and DETACH commands.
**
** $Id: attach.c,v 1.80 2008/11/19 09:05:27 danielk1977 Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_ATTACH
/*
** Resolve an expression that was part of an ATTACH or DETACH statement. This
** is slightly different from resolving a normal SQL expression, because simple
................................................................................
  sqlite3ExprCode(pParse, pFilename, regArgs);
  sqlite3ExprCode(pParse, pDbname, regArgs+1);
  sqlite3ExprCode(pParse, pKey, regArgs+2);

  assert( v || db->mallocFailed );
  if( v ){
    sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-pFunc->nArg, regArgs+3);

    sqlite3VdbeChangeP5(v, pFunc->nArg);
    sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF);

    /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
    ** statement only). For DETACH, set it to false (expire all existing
    ** statements).
    */
    sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH));







|







 







>
|







7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
...
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
**    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.
**
*************************************************************************
** This file contains code used to implement the ATTACH and DETACH commands.
**
** $Id: attach.c,v 1.81 2008/12/10 16:45:51 drh Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_ATTACH
/*
** Resolve an expression that was part of an ATTACH or DETACH statement. This
** is slightly different from resolving a normal SQL expression, because simple
................................................................................
  sqlite3ExprCode(pParse, pFilename, regArgs);
  sqlite3ExprCode(pParse, pDbname, regArgs+1);
  sqlite3ExprCode(pParse, pKey, regArgs+2);

  assert( v || db->mallocFailed );
  if( v ){
    sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-pFunc->nArg, regArgs+3);
    assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg );
    sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg));
    sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF);

    /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
    ** statement only). For DETACH, set it to false (expire all existing
    ** statements).
    */
    sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH));

Changes to src/btree.c.

5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
...
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
...
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
...
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
...
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
...
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
...
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802

803
804
805
806
807
808
809
810
811
812
813
814
815
816
...
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890

891

892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
...
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
...
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
....
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
....
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
....
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
....
1630
1631
1632
1633
1634
1635
1636

1637
1638
1639
1640
1641
1642
1643
1644

1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
....
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
....
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
....
1911
1912
1913
1914
1915
1916
1917

1918
1919
1920
1921
1922
1923
1924
1925
....
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
....
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
....
2809
2810
2811
2812
2813
2814
2815

2816
2817
2818
2819
2820
2821
2822
....
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
....
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
....
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
....
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
....
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
....
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
....
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
....
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
....
3881
3882
3883
3884
3885
3886
3887

3888
3889
3890
3891
3892
3893
3894
3895
....
4509
4510
4511
4512
4513
4514
4515
4516

4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
....
4686
4687
4688
4689
4690
4691
4692


4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
....
4772
4773
4774
4775
4776
4777
4778

4779
4780
4781
4782
4783
4784
4785
....
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
....
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
....
5202
5203
5204
5205
5206
5207
5208

5209
5210
5211
5212
5213
5214
5215
5216
....
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
....
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
....
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
....
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
....
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
** 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 1.545 2008/12/05 22:40:08 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

................................................................................
  /* If this is an intKey table, then the above call to BtreeKeySize()
  ** stores the integer key in pCur->nKey. In this case this value is
  ** all that is required. Otherwise, if pCur is not open on an intKey
  ** table, then malloc space for and store the pCur->nKey bytes of key 
  ** data.
  */
  if( rc==SQLITE_OK && 0==pCur->apPage[0]->intKey){
    void *pKey = sqlite3Malloc(pCur->nKey);
    if( pKey ){
      rc = sqlite3BtreeKey(pCur, 0, pCur->nKey, pKey);
      if( rc==SQLITE_OK ){
        pCur->pKey = pKey;
      }else{
        sqlite3_free(pKey);
      }
    }else{
      rc = SQLITE_NOMEM;
................................................................................
** sqlite3BtreeParseCellPtr(). Using some compilers, this will be faster.
*/
void sqlite3BtreeParseCellPtr(
  MemPage *pPage,         /* Page containing the cell */
  u8 *pCell,              /* Pointer to the cell text. */
  CellInfo *pInfo         /* Fill in this structure */
){
  int n;                  /* Number bytes in cell content header */
  u32 nPayload;           /* Number of bytes of cell payload */

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  pInfo->pCell = pCell;
  assert( pPage->leaf==0 || pPage->leaf==1 );
  n = pPage->childPtrSize;
................................................................................
  assert( n==4-4*pPage->leaf );
  if( pPage->intKey ){
    if( pPage->hasData ){
      n += getVarint32(&pCell[n], nPayload);
    }else{
      nPayload = 0;
    }
    n += getVarint(&pCell[n], (u64*)&pInfo->nKey);
    pInfo->nData = nPayload;
  }else{
    pInfo->nData = 0;
    n += getVarint32(&pCell[n], nPayload);
    pInfo->nKey = nPayload;
  }
  pInfo->nPayload = nPayload;
................................................................................
  pInfo->nHeader = n;
  if( likely(nPayload<=pPage->maxLocal) ){
    /* This is the (easy) common case where the entire payload fits
    ** on the local page.  No overflow is required.
    */
    int nSize;          /* Total size of cell content in bytes */
    nSize = nPayload + n;
    pInfo->nLocal = nPayload;
    pInfo->iOverflow = 0;
    if( (nSize & ~3)==0 ){
      nSize = 4;        /* Minimum cell size is 4 */
    }
    pInfo->nSize = nSize;
  }else{
    /* If the payload will not fit completely on the local page, we have
    ** to decide how much to store locally and how much to spill onto
    ** overflow pages.  The strategy is to minimize the amount of unused
    ** space on overflow pages while keeping the amount of local storage
    ** in between minLocal and maxLocal.
    **
................................................................................
    int maxLocal;  /* Maximum amount of payload held locally */
    int surplus;   /* Overflow payload available for local storage */

    minLocal = pPage->minLocal;
    maxLocal = pPage->maxLocal;
    surplus = minLocal + (nPayload - minLocal)%(pPage->pBt->usableSize - 4);
    if( surplus <= maxLocal ){
      pInfo->nLocal = surplus;
    }else{
      pInfo->nLocal = minLocal;
    }
    pInfo->iOverflow = pInfo->nLocal + n;
    pInfo->nSize = pInfo->iOverflow + 4;
  }
}
#define parseCell(pPage, iCell, pInfo) \
  sqlite3BtreeParseCellPtr((pPage), findCell((pPage), (iCell)), (pInfo))
void sqlite3BtreeParseCell(
  MemPage *pPage,         /* Page containing the cell */
................................................................................
  data = pPage->aData;
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( pPage->pBt );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( nByte>=0 );  /* Minimum cell size is 4 */
  assert( pPage->nFree>=nByte );
  assert( pPage->nOverflow==0 );
  pPage->nFree -= nByte;
  hdr = pPage->hdrOffset;

  nFrag = data[hdr+7];
  if( nFrag<60 ){
    /* Search the freelist looking for a slot big enough to satisfy the
    ** space request. */
    addr = hdr+1;
    while( (pc = get2byte(&data[addr]))>0 ){
      size = get2byte(&data[pc+2]);
      if( size>=nByte ){

        if( size<nByte+4 ){
          memcpy(&data[addr], &data[pc], 2);
          data[hdr+7] = nFrag + size - nByte;
          return pc;
        }else{
          put2byte(&data[pc+2], size-nByte);
          return pc + size - nByte;
        }
      }
      addr = pc;
    }
  }

  /* Allocate memory from the gap in between the cell pointer array
................................................................................
  if ( pbegin>pPage->pBt->usableSize-4 ) {
    return SQLITE_CORRUPT_BKPT;
  }
  assert( pbegin>addr || pbegin==0 );
  put2byte(&data[addr], start);
  put2byte(&data[start], pbegin);
  put2byte(&data[start+2], size);
  pPage->nFree += size;

  /* Coalesce adjacent free blocks */
  addr = pPage->hdrOffset + 1;
  while( (pbegin = get2byte(&data[addr]))>0 ){
    int pnext, psize;
    assert( pbegin>addr );
    assert( pbegin<=pPage->pBt->usableSize-4 );
    pnext = get2byte(&data[pbegin]);
    psize = get2byte(&data[pbegin+2]);
    if( pbegin + psize + 3 >= pnext && pnext>0 ){
      int frag = pnext - (pbegin+psize);
      if( (frag<0) || (frag>data[pPage->hdrOffset+7]) ){
        return SQLITE_CORRUPT_BKPT;
      }
      data[pPage->hdrOffset+7] -= frag;

      put2byte(&data[pbegin], get2byte(&data[pnext]));

      put2byte(&data[pbegin+2], pnext+get2byte(&data[pnext+2])-pbegin);
    }else{
      addr = pbegin;
    }
  }

  /* If the cell content area begins with a freeblock, remove it. */
  if( data[hdr+1]==data[hdr+5] && data[hdr+2]==data[hdr+6] ){
    int top;
    pbegin = get2byte(&data[hdr+1]);
    memcpy(&data[hdr+1], &data[pbegin], 2);
    top = get2byte(&data[hdr+5]);
    put2byte(&data[hdr+5], top + get2byte(&data[pbegin+2]));
  }
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  return SQLITE_OK;
}

/*
** Decode the flags byte (the first byte of the header) for a page
................................................................................
**         PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF
*/
static int decodeFlags(MemPage *pPage, int flagByte){
  BtShared *pBt;     /* A copy of pPage->pBt */

  assert( pPage->hdrOffset==(pPage->pgno==1 ? 100 : 0) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  pPage->leaf = flagByte>>3;  assert( PTF_LEAF == 1<<3 );
  flagByte &= ~PTF_LEAF;
  pPage->childPtrSize = 4-4*pPage->leaf;
  pBt = pPage->pBt;
  if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
    pPage->intKey = 1;
    pPage->hasData = pPage->leaf;
    pPage->maxLocal = pBt->maxLeaf;
................................................................................
  assert( pPage->pBt!=0 );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );
  assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );
  assert( pPage->aData == sqlite3PagerGetData(pPage->pDbPage) );

  if( !pPage->isInit ){
    int pc;            /* Address of a freeblock within pPage->aData[] */
    int hdr;           /* Offset to beginning of page header */
    u8 *data;          /* Equal to pPage->aData */
    BtShared *pBt;        /* The main btree structure */
    int usableSize;    /* Amount of usable space on each page */
    int cellOffset;    /* Offset from start of page to first cell pointer */
    int nFree;         /* Number of unused bytes on the page */
    int top;           /* First byte of the cell content area */

    pBt = pPage->pBt;

    hdr = pPage->hdrOffset;
    data = pPage->aData;
    if( decodeFlags(pPage, data[hdr]) ) return SQLITE_CORRUPT_BKPT;
    assert( pBt->pageSize>=512 && pBt->pageSize<=32768 );
................................................................................
      if( next>0 && next<=pc+size+3 ){
        /* Free blocks must be in accending order */
        return SQLITE_CORRUPT_BKPT; 
      }
      nFree += size;
      pc = next;
    }
    pPage->nFree = nFree;
    if( nFree>=usableSize ){
      /* Free space cannot exceed total page size */
      return SQLITE_CORRUPT_BKPT; 
    }

#if 0
  /* Check that all the offsets in the cell offset array are within range. 
................................................................................
/*
** Set up a raw page so that it looks like a database page holding
** no entries.
*/
static void zeroPage(MemPage *pPage, int flags){
  unsigned char *data = pPage->aData;
  BtShared *pBt = pPage->pBt;
  int hdr = pPage->hdrOffset;
  int first;

  assert( sqlite3PagerPagenumber(pPage->pDbPage)==pPage->pgno );
  assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
  assert( sqlite3PagerGetData(pPage->pDbPage) == data );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( sqlite3_mutex_held(pBt->mutex) );
  /*memset(&data[hdr], 0, pBt->usableSize - hdr);*/
................................................................................
  int flags,              /* Options */
  int vfsFlags            /* Flags passed through to sqlite3_vfs.xOpen() */
){
  sqlite3_vfs *pVfs;      /* The VFS to use for this btree */
  BtShared *pBt = 0;      /* Shared part of btree structure */
  Btree *p;               /* Handle to return */
  int rc = SQLITE_OK;
  int nReserve;
  unsigned char zDbHeader[100];

  /* Set the variable isMemdb to true for an in-memory database, or 
  ** false for a file-based database. This symbol is only required if
  ** either of the shared-data or autovacuum features are compiled 
  ** into the library.
  */
................................................................................
**
** If parameter nReserve is less than zero, then the number of reserved
** bytes per page is left unchanged.
*/
int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve){
  int rc = SQLITE_OK;
  BtShared *pBt = p->pBt;

  sqlite3BtreeEnter(p);
  if( pBt->pageSizeFixed ){
    sqlite3BtreeLeave(p);
    return SQLITE_READONLY;
  }
  if( nReserve<0 ){
    nReserve = pBt->pageSize - pBt->usableSize;
  }

  if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
        ((pageSize-1)&pageSize)==0 ){
    assert( (pageSize & 7)==0 );
    assert( !pBt->pPage1 && !pBt->pCursor );
    pBt->pageSize = pageSize;
    freeTempSpace(pBt);
    rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize);
  }
  pBt->usableSize = pBt->pageSize - nReserve;
  sqlite3BtreeLeave(p);
  return rc;
}

/*
** Return the currently defined page size
*/
................................................................................
*/
int sqlite3BtreeSetAutoVacuum(Btree *p, int autoVacuum){
#ifdef SQLITE_OMIT_AUTOVACUUM
  return SQLITE_READONLY;
#else
  BtShared *pBt = p->pBt;
  int rc = SQLITE_OK;
  int av = (autoVacuum?1:0);

  sqlite3BtreeEnter(p);
  if( pBt->pageSizeFixed && av!=pBt->autoVacuum ){
    rc = SQLITE_READONLY;
  }else{
    pBt->autoVacuum = av;
  }
................................................................................
      /* After reading the first page of the database assuming a page size
      ** of BtShared.pageSize, we have discovered that the page-size is
      ** actually pageSize. Unlock the database, leave pBt->pPage1 at
      ** zero and return SQLITE_OK. The caller will call this function
      ** again with the correct page-size.
      */
      releasePage(pPage1);
      pBt->usableSize = usableSize;
      pBt->pageSize = pageSize;
      freeTempSpace(pBt);
      sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize);
      return SQLITE_OK;
    }
    if( usableSize<500 ){
      goto page1_init_failed;
    }
................................................................................
  rc = sqlite3PagerWrite(pP1->pDbPage);
  if( rc ) return rc;
  memcpy(data, zMagicHeader, sizeof(zMagicHeader));
  assert( sizeof(zMagicHeader)==16 );
  put2byte(&data[16], pBt->pageSize);
  data[18] = 1;
  data[19] = 1;

  data[20] = pBt->pageSize - pBt->usableSize;
  data[21] = 64;
  data[22] = 32;
  data[23] = 32;
  memset(&data[24], 0, 100-24);
  zeroPage(pP1, PTF_INTKEY|PTF_LEAF|PTF_LEAFDATA );
  pBt->pageSizeFixed = 1;
#ifndef SQLITE_OMIT_AUTOVACUUM
................................................................................
** map entries for the overflow pages as well.
*/
static int setChildPtrmaps(MemPage *pPage){
  int i;                             /* Counter variable */
  int nCell;                         /* Number of cells in page pPage */
  int rc;                            /* Return code */
  BtShared *pBt = pPage->pBt;
  int isInitOrig = pPage->isInit;
  Pgno pgno = pPage->pgno;

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  rc = sqlite3BtreeInitPage(pPage);
  if( rc!=SQLITE_OK ){
    goto set_child_ptrmaps_out;
  }
................................................................................
  if( eType==PTRMAP_OVERFLOW2 ){
    /* The pointer is always the first 4 bytes of the page in this case.  */
    if( get4byte(pPage->aData)!=iFrom ){
      return SQLITE_CORRUPT_BKPT;
    }
    put4byte(pPage->aData, iTo);
  }else{
    int isInitOrig = pPage->isInit;
    int i;
    int nCell;

    sqlite3BtreeInitPage(pPage);
    nCell = pPage->nCell;

    for(i=0; i<nCell; i++){
................................................................................
  BtCursor *pCur                         /* Space for new cursor */
){
  int rc;
  Pgno nPage;
  BtShared *pBt = p->pBt;

  assert( sqlite3BtreeHoldsMutex(p) );

  if( wrFlag ){
    if( pBt->readOnly ){
      return SQLITE_READONLY;
    }
    if( checkReadLocks(p, iTable, 0, 0) ){
      return SQLITE_LOCKED;
    }
................................................................................
  /* Now that no other errors can occur, finish filling in the BtCursor
  ** variables, link the cursor into the BtShared list and set *ppCur (the
  ** output argument to this function).
  */
  pCur->pKeyInfo = pKeyInfo;
  pCur->pBtree = p;
  pCur->pBt = pBt;
  pCur->wrFlag = wrFlag;
  pCur->pNext = pBt->pCursor;
  if( pCur->pNext ){
    pCur->pNext->pPrev = pCur;
  }
  pBt->pCursor = pCur;
  pCur->eState = CURSOR_INVALID;

................................................................................
  assert( pPage );
  assert( pCur->eState==CURSOR_VALID );
  assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
  assert( cursorHoldsMutex(pCur) );

  getCellInfo(pCur);
  aPayload = pCur->info.pCell + pCur->info.nHeader;
  nKey = (pPage->intKey ? 0 : pCur->info.nKey);

  if( skipKey ){
    offset += nKey;
  }
  if( offset+amt > nKey+pCur->info.nData 
   || &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize]
  ){
................................................................................
  assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
  getCellInfo(pCur);
  aPayload = pCur->info.pCell;
  aPayload += pCur->info.nHeader;
  if( pPage->intKey ){
    nKey = 0;
  }else{
    nKey = pCur->info.nKey;
  }
  if( skipKey ){
    aPayload += nKey;
    nLocal = pCur->info.nLocal - nKey;
  }else{
    nLocal = pCur->info.nLocal;
    if( nLocal>nKey ){
................................................................................
      assert( pCur->apPage[pCur->iPage]->nCell==0 );
      *pRes = 1;
    }else{
      assert( pCur->eState==CURSOR_VALID );
      *pRes = 0;
      rc = moveToRightmost(pCur);
      getCellInfo(pCur);
      pCur->atLast = rc==SQLITE_OK;
    }
  }
  return rc;
}

/* Move the cursor so that it points to an entry near the key 
** specified by pIdxKey or intKey.   Return a success code.
................................................................................
    lwr = 0;
    upr = pPage->nCell-1;
    if( !pPage->intKey && pIdxKey==0 ){
      rc = SQLITE_CORRUPT_BKPT;
      goto moveto_finish;
    }
    if( biasRight ){
      pCur->aiIdx[pCur->iPage] = upr;
    }else{
      pCur->aiIdx[pCur->iPage] = (upr+lwr)/2;
    }
    if( lwr<=upr ) for(;;){
      void *pCellKey;
      i64 nCellKey;
      int idx = pCur->aiIdx[pCur->iPage];
      pCur->info.nSize = 0;
      pCur->validNKey = 1;
................................................................................
          c = +1;
        }
      }else{
        int available;
        pCellKey = (void *)fetchPayload(pCur, &available, 0);
        nCellKey = pCur->info.nKey;
        if( available>=nCellKey ){
          c = sqlite3VdbeRecordCompare(nCellKey, pCellKey, pIdxKey);
        }else{
          pCellKey = sqlite3Malloc( nCellKey );
          if( pCellKey==0 ){
            rc = SQLITE_NOMEM;
            goto moveto_finish;
          }
          rc = sqlite3BtreeKey(pCur, 0, nCellKey, (void *)pCellKey);
          c = sqlite3VdbeRecordCompare(nCellKey, pCellKey, pIdxKey);
          sqlite3_free(pCellKey);
          if( rc ) goto moveto_finish;
        }
      }
      if( c==0 ){
        pCur->info.nKey = nCellKey;
................................................................................
      }else{
        upr = idx-1;
      }
      if( lwr>upr ){
        pCur->info.nKey = nCellKey;
        break;
      }
      pCur->aiIdx[pCur->iPage] = (lwr+upr)/2;
    }
    assert( lwr==upr+1 );
    assert( pPage->isInit );
    if( pPage->leaf ){
      chldPg = 0;
    }else if( lwr>=pPage->nCell ){
      chldPg = get4byte(&pPage->aData[pPage->hdrOffset+8]);
................................................................................
    }
    if( chldPg==0 ){
      assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
      if( pRes ) *pRes = c;
      rc = SQLITE_OK;
      goto moveto_finish;
    }
    pCur->aiIdx[pCur->iPage] = lwr;
    pCur->info.nSize = 0;
    pCur->validNKey = 0;
    rc = moveToChild(pCur, chldPg);
    if( rc ) goto moveto_finish;
  }
moveto_finish:
  return rc;
................................................................................
  int *pRes           /* Write search results here */
){
  int rc;                    /* Status code */
  UnpackedRecord *pIdxKey;   /* Unpacked index key */
  UnpackedRecord aSpace[16]; /* Temp space for pIdxKey - to avoid a malloc */

  if( pKey ){

    pIdxKey = sqlite3VdbeRecordUnpack(pCur->pKeyInfo, nKey, pKey,
                                      aSpace, sizeof(aSpace));
    if( pIdxKey==0 ) return SQLITE_NOMEM;
  }else{
    pIdxKey = 0;
  }
  rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias, pRes);
  if( pKey ){
................................................................................
  
  /* Fill in the payload */
  nPayload = nData + nZero;
  if( pPage->intKey ){
    pSrc = pData;
    nSrc = nData;
    nData = 0;
  }else{

    nPayload += nKey;
    pSrc = pKey;
    nSrc = nKey;
  }
  *pnSize = info.nSize;
  spaceLeft = info.nLocal;
  pPayload = &pCell[nHeader];
  pPrior = &pCell[info.iOverflow];

  while( nPayload>0 ){
    if( spaceLeft==0 ){
      int isExact = 0;
#ifndef SQLITE_OMIT_AUTOVACUUM
      Pgno pgnoPtrmap = pgnoOvfl; /* Overflow page pointer-map entry page */
      if( pBt->autoVacuum ){
        do{
          pgnoOvfl++;
        } while( 
          PTRMAP_ISPAGE(pBt, pgnoOvfl) || pgnoOvfl==PENDING_BYTE_PAGE(pBt) 
        );
        if( pgnoOvfl>1 ){
          /* isExact = 1; */
        }
      }
#endif
      rc = allocateBtreePage(pBt, &pOvfl, &pgnoOvfl, pgnoOvfl, isExact);
#ifndef SQLITE_OMIT_AUTOVACUUM
      /* If the database supports auto-vacuum, and the second or subsequent
      ** overflow page is being allocated, add an entry to the pointer-map
      ** for that page now. 
      **
      ** If this is the first overflow page, then write a partial entry 
      ** to the pointer-map. If we write nothing to this pointer-map slot,
................................................................................
  int ins;          /* Index in data[] where new cell pointer is inserted */
  int hdr;          /* Offset into data[] of the page header */
  int cellOffset;   /* Address of first cell pointer in data[] */
  u8 *data;         /* The content of the whole page */
  u8 *ptr;          /* Used for moving information around in data[] */

  assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );


  assert( sz==cellSizePtr(pPage, pCell) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  if( pPage->nOverflow || sz+2>pPage->nFree ){
    if( pTemp ){
      memcpy(pTemp+nSkip, pCell+nSkip, sz-nSkip);
      pCell = pTemp;
    }
    j = pPage->nOverflow++;
    assert( j<(int)(sizeof(pPage->aOvfl)/sizeof(pPage->aOvfl[0])) );
    pPage->aOvfl[j].pCell = pCell;
    pPage->aOvfl[j].idx = i;
    pPage->nFree = 0;
  }else{
    int rc = sqlite3PagerWrite(pPage->pDbPage);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    assert( sqlite3PagerIswriteable(pPage->pDbPage) );
................................................................................
  int hdr;          /* Index of page header */
  int cellptr;      /* Address of next cell pointer */
  int cellbody;     /* Address of next cell body */
  u8 *data;         /* Data for the page */

  assert( pPage->nOverflow==0 );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  totalSize = 0;
  for(i=0; i<nCell; i++){
    totalSize += aSize[i];
  }
  assert( totalSize+2*nCell<=pPage->nFree );
  assert( pPage->nCell==0 );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
................................................................................
      put2byte(&data[cellptr], cellbody);
      memcpy(&data[cellbody], apCell[i], aSize[i]);
      cellptr += 2;
      cellbody += aSize[i];
    }
    assert( cellbody==pPage->pBt->usableSize );
  }
  pPage->nCell = nCell;
}

/*
** The following parameters determine how many adjacent pages get involved
** in a balancing operation.  NN is the number of neighbors on either side
** of the page that participate in the balancing operation.  NB is the
** total number of pages that participate, including the target page and
................................................................................
    int limit = pOld->nCell+pOld->nOverflow;
    for(j=0; j<limit; j++){
      assert( nCell<nMaxCells );
      apCell[nCell] = findOverflowCell(pOld, j);
      szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
      if( ISAUTOVACUUM ){
        int a;
        aFrom[nCell] = i;
        for(a=0; a<pOld->nOverflow; a++){
          if( pOld->aOvfl[a].pCell==apCell[nCell] ){
            aFrom[nCell] = 0xFF;
            break;
          }
        }
      }
................................................................................
        assert( iSpace1<=pBt->pageSize );
        memcpy(pTemp, apDiv[i], sz);
        apCell[nCell] = pTemp+leafCorrection;
        if( ISAUTOVACUUM ){
          aFrom[nCell] = 0xFF;
        }
        dropCell(pParent, nxDiv, sz);

        szCell[nCell] -= leafCorrection;
        assert( get4byte(pTemp)==pgnoOld[i] );
        if( !pOld->leaf ){
          assert( leafCorrection==0 );
          /* The right pointer of the child page pOld becomes the left
          ** pointer of the divider cell */
          memcpy(apCell[nCell], &pOld->aData[pOld->hdrOffset+8], 4);
        }else{
................................................................................
    rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
    if( rc==SQLITE_OK ){
      put4byte(&pP1[36 + idx*4], iMeta);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( idx==7 ){
        assert( pBt->autoVacuum || iMeta==0 );
        assert( iMeta==0 || iMeta==1 );
        pBt->incrVacuum = iMeta;
      }
#endif
    }
  }
  sqlite3BtreeLeave(p);
  return rc;
}
................................................................................
    /* Check payload overflow pages
    */
    sqlite3_snprintf(sizeof(zContext), zContext,
             "On tree page %d cell %d: ", iPage, i);
    pCell = findCell(pPage,i);
    sqlite3BtreeParseCellPtr(pPage, pCell, &info);
    sz = info.nData;
    if( !pPage->intKey ) sz += info.nKey;
    assert( sz==info.nPayload );
    if( sz>info.nLocal ){
      int nPage = (sz - info.nLocal + usableSize - 5)/(usableSize - 4);
      Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pBt->autoVacuum ){
        checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, iPage, zContext);
................................................................................
  nToPage = pagerPagecount(pBtTo);
  nFromPage = pagerPagecount(pBtFrom);
  iSkip = PENDING_BYTE_PAGE(pBtTo);

  /* Variable nNewPage is the number of pages required to store the
  ** contents of pFrom using the current page-size of pTo.
  */
  nNewPage = ((i64)nFromPage * (i64)nFromPageSize + (i64)nToPageSize - 1) / 
      (i64)nToPageSize;

  for(i=1; rc==SQLITE_OK && (i<=nToPage || i<=nNewPage); i++){

    /* Journal the original page.
    **
    ** iSkip is the page number of the locking page (PENDING_BYTE_PAGE)
    ** in database *pTo (before the copy). This page is never written 
................................................................................

      for(
        iOff=(i-1)*nToPageSize; 
        rc==SQLITE_OK && iOff<i*nToPageSize; 
        iOff += nFromPageSize
      ){
        DbPage *pFromPage = 0;
        Pgno iFrom = (iOff/nFromPageSize)+1;

        if( iFrom==PENDING_BYTE_PAGE(pBtFrom) ){
          continue;
        }

        rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage);
        if( rc==SQLITE_OK ){
................................................................................
        i64 iOff;
        for(
          iOff=iPending; 
          rc==SQLITE_OK && iOff<(iPending+nToPageSize); 
          iOff += nFromPageSize
        ){
          DbPage *pFromPage = 0;
          Pgno iFrom = (iOff/nFromPageSize)+1;
  
          if( iFrom==PENDING_BYTE_PAGE(pBtFrom) || iFrom>nFromPage ){
            continue;
          }
  
          rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage);
          if( rc==SQLITE_OK ){







|







 







|

|







 







|







 







|







 







|




|







 







|

|

|







 







|










>


|


|
|







 







|




|






|


|
>
|
>
|










|
|







 







|







 







|
|


|
|
|
|







 







|







 







|
|







 







|







 







>








>








|







 







|







 







|
|







 







>
|







 







|







 







|







 







>







 







|







 







|







 







|







 







|







 







|

|







 







|

|




|







 







|







 







|







 







>
|







 







|
>
|

|








<








<
<
|
<

|







 







>
>










|







 







>







 







|







 







|







 







>
|







 







|







 







|







 







|
|







 







|







 







|







5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
...
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
...
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
...
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
...
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
...
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
...
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
...
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
...
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
...
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
....
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
....
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
....
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
....
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
....
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
....
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
....
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
....
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
....
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
....
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
....
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
....
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
....
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
....
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
....
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
....
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
....
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
....
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
....
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
....
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536

4537
4538
4539
4540
4541
4542
4543
4544


4545

4546
4547
4548
4549
4550
4551
4552
4553
4554
....
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
....
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
....
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
....
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
....
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
....
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
....
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
....
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
....
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
....
7309
7310
7311
7312
7313
7314
7315
7316
7317
7318
7319
7320
7321
7322
7323
** 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 1.546 2008/12/10 16:45:51 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

................................................................................
  /* If this is an intKey table, then the above call to BtreeKeySize()
  ** stores the integer key in pCur->nKey. In this case this value is
  ** all that is required. Otherwise, if pCur is not open on an intKey
  ** table, then malloc space for and store the pCur->nKey bytes of key 
  ** data.
  */
  if( rc==SQLITE_OK && 0==pCur->apPage[0]->intKey){
    void *pKey = sqlite3Malloc( (int)pCur->nKey );
    if( pKey ){
      rc = sqlite3BtreeKey(pCur, 0, (int)pCur->nKey, pKey);
      if( rc==SQLITE_OK ){
        pCur->pKey = pKey;
      }else{
        sqlite3_free(pKey);
      }
    }else{
      rc = SQLITE_NOMEM;
................................................................................
** sqlite3BtreeParseCellPtr(). Using some compilers, this will be faster.
*/
void sqlite3BtreeParseCellPtr(
  MemPage *pPage,         /* Page containing the cell */
  u8 *pCell,              /* Pointer to the cell text. */
  CellInfo *pInfo         /* Fill in this structure */
){
  u16 n;                  /* Number bytes in cell content header */
  u32 nPayload;           /* Number of bytes of cell payload */

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );

  pInfo->pCell = pCell;
  assert( pPage->leaf==0 || pPage->leaf==1 );
  n = pPage->childPtrSize;
................................................................................
  assert( n==4-4*pPage->leaf );
  if( pPage->intKey ){
    if( pPage->hasData ){
      n += getVarint32(&pCell[n], nPayload);
    }else{
      nPayload = 0;
    }
    n += (u16)getVarint(&pCell[n], (u64*)&pInfo->nKey);
    pInfo->nData = nPayload;
  }else{
    pInfo->nData = 0;
    n += getVarint32(&pCell[n], nPayload);
    pInfo->nKey = nPayload;
  }
  pInfo->nPayload = nPayload;
................................................................................
  pInfo->nHeader = n;
  if( likely(nPayload<=pPage->maxLocal) ){
    /* This is the (easy) common case where the entire payload fits
    ** on the local page.  No overflow is required.
    */
    int nSize;          /* Total size of cell content in bytes */
    nSize = nPayload + n;
    pInfo->nLocal = (u16)nPayload;
    pInfo->iOverflow = 0;
    if( (nSize & ~3)==0 ){
      nSize = 4;        /* Minimum cell size is 4 */
    }
    pInfo->nSize = (int)nSize;
  }else{
    /* If the payload will not fit completely on the local page, we have
    ** to decide how much to store locally and how much to spill onto
    ** overflow pages.  The strategy is to minimize the amount of unused
    ** space on overflow pages while keeping the amount of local storage
    ** in between minLocal and maxLocal.
    **
................................................................................
    int maxLocal;  /* Maximum amount of payload held locally */
    int surplus;   /* Overflow payload available for local storage */

    minLocal = pPage->minLocal;
    maxLocal = pPage->maxLocal;
    surplus = minLocal + (nPayload - minLocal)%(pPage->pBt->usableSize - 4);
    if( surplus <= maxLocal ){
      pInfo->nLocal = (u16)surplus;
    }else{
      pInfo->nLocal = (u16)minLocal;
    }
    pInfo->iOverflow = (u16)(pInfo->nLocal + n);
    pInfo->nSize = pInfo->iOverflow + 4;
  }
}
#define parseCell(pPage, iCell, pInfo) \
  sqlite3BtreeParseCellPtr((pPage), findCell((pPage), (iCell)), (pInfo))
void sqlite3BtreeParseCell(
  MemPage *pPage,         /* Page containing the cell */
................................................................................
  data = pPage->aData;
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( pPage->pBt );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( nByte>=0 );  /* Minimum cell size is 4 */
  assert( pPage->nFree>=nByte );
  assert( pPage->nOverflow==0 );
  pPage->nFree -= (u16)nByte;
  hdr = pPage->hdrOffset;

  nFrag = data[hdr+7];
  if( nFrag<60 ){
    /* Search the freelist looking for a slot big enough to satisfy the
    ** space request. */
    addr = hdr+1;
    while( (pc = get2byte(&data[addr]))>0 ){
      size = get2byte(&data[pc+2]);
      if( size>=nByte ){
        int x = size - nByte;
        if( size<nByte+4 ){
          memcpy(&data[addr], &data[pc], 2);
          data[hdr+7] = (u8)(nFrag + x);
          return pc;
        }else{
          put2byte(&data[pc+2], x);
          return pc + x;
        }
      }
      addr = pc;
    }
  }

  /* Allocate memory from the gap in between the cell pointer array
................................................................................
  if ( pbegin>pPage->pBt->usableSize-4 ) {
    return SQLITE_CORRUPT_BKPT;
  }
  assert( pbegin>addr || pbegin==0 );
  put2byte(&data[addr], start);
  put2byte(&data[start], pbegin);
  put2byte(&data[start+2], size);
  pPage->nFree += (u16)size;

  /* Coalesce adjacent free blocks */
  addr = pPage->hdrOffset + 1;
  while( (pbegin = get2byte(&data[addr]))>0 ){
    int pnext, psize, x;
    assert( pbegin>addr );
    assert( pbegin<=pPage->pBt->usableSize-4 );
    pnext = get2byte(&data[pbegin]);
    psize = get2byte(&data[pbegin+2]);
    if( pbegin + psize + 3 >= pnext && pnext>0 ){
      int frag = pnext - (pbegin+psize);
      if( (frag<0) || (frag>(int)data[pPage->hdrOffset+7]) ){
        return SQLITE_CORRUPT_BKPT;
      }
      data[pPage->hdrOffset+7] -= (u8)frag;
      x = get2byte(&data[pnext]);
      put2byte(&data[pbegin], x);
      x = pnext + get2byte(&data[pnext+2]) - pbegin;
      put2byte(&data[pbegin+2], x);
    }else{
      addr = pbegin;
    }
  }

  /* If the cell content area begins with a freeblock, remove it. */
  if( data[hdr+1]==data[hdr+5] && data[hdr+2]==data[hdr+6] ){
    int top;
    pbegin = get2byte(&data[hdr+1]);
    memcpy(&data[hdr+1], &data[pbegin], 2);
    top = get2byte(&data[hdr+5]) + get2byte(&data[pbegin+2]);
    put2byte(&data[hdr+5], top);
  }
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  return SQLITE_OK;
}

/*
** Decode the flags byte (the first byte of the header) for a page
................................................................................
**         PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF
*/
static int decodeFlags(MemPage *pPage, int flagByte){
  BtShared *pBt;     /* A copy of pPage->pBt */

  assert( pPage->hdrOffset==(pPage->pgno==1 ? 100 : 0) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  pPage->leaf = (u8)(flagByte>>3);  assert( PTF_LEAF == 1<<3 );
  flagByte &= ~PTF_LEAF;
  pPage->childPtrSize = 4-4*pPage->leaf;
  pBt = pPage->pBt;
  if( flagByte==(PTF_LEAFDATA | PTF_INTKEY) ){
    pPage->intKey = 1;
    pPage->hasData = pPage->leaf;
    pPage->maxLocal = pBt->maxLeaf;
................................................................................
  assert( pPage->pBt!=0 );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( pPage->pgno==sqlite3PagerPagenumber(pPage->pDbPage) );
  assert( pPage == sqlite3PagerGetExtra(pPage->pDbPage) );
  assert( pPage->aData == sqlite3PagerGetData(pPage->pDbPage) );

  if( !pPage->isInit ){
    u16 pc;            /* Address of a freeblock within pPage->aData[] */
    u8 hdr;            /* Offset to beginning of page header */
    u8 *data;          /* Equal to pPage->aData */
    BtShared *pBt;        /* The main btree structure */
    u16 usableSize;    /* Amount of usable space on each page */
    u16 cellOffset;    /* Offset from start of page to first cell pointer */
    u16 nFree;         /* Number of unused bytes on the page */
    u16 top;           /* First byte of the cell content area */

    pBt = pPage->pBt;

    hdr = pPage->hdrOffset;
    data = pPage->aData;
    if( decodeFlags(pPage, data[hdr]) ) return SQLITE_CORRUPT_BKPT;
    assert( pBt->pageSize>=512 && pBt->pageSize<=32768 );
................................................................................
      if( next>0 && next<=pc+size+3 ){
        /* Free blocks must be in accending order */
        return SQLITE_CORRUPT_BKPT; 
      }
      nFree += size;
      pc = next;
    }
    pPage->nFree = (u16)nFree;
    if( nFree>=usableSize ){
      /* Free space cannot exceed total page size */
      return SQLITE_CORRUPT_BKPT; 
    }

#if 0
  /* Check that all the offsets in the cell offset array are within range. 
................................................................................
/*
** Set up a raw page so that it looks like a database page holding
** no entries.
*/
static void zeroPage(MemPage *pPage, int flags){
  unsigned char *data = pPage->aData;
  BtShared *pBt = pPage->pBt;
  u8 hdr = pPage->hdrOffset;
  u16 first;

  assert( sqlite3PagerPagenumber(pPage->pDbPage)==pPage->pgno );
  assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
  assert( sqlite3PagerGetData(pPage->pDbPage) == data );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( sqlite3_mutex_held(pBt->mutex) );
  /*memset(&data[hdr], 0, pBt->usableSize - hdr);*/
................................................................................
  int flags,              /* Options */
  int vfsFlags            /* Flags passed through to sqlite3_vfs.xOpen() */
){
  sqlite3_vfs *pVfs;      /* The VFS to use for this btree */
  BtShared *pBt = 0;      /* Shared part of btree structure */
  Btree *p;               /* Handle to return */
  int rc = SQLITE_OK;
  u8 nReserve;
  unsigned char zDbHeader[100];

  /* Set the variable isMemdb to true for an in-memory database, or 
  ** false for a file-based database. This symbol is only required if
  ** either of the shared-data or autovacuum features are compiled 
  ** into the library.
  */
................................................................................
**
** If parameter nReserve is less than zero, then the number of reserved
** bytes per page is left unchanged.
*/
int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve){
  int rc = SQLITE_OK;
  BtShared *pBt = p->pBt;
  assert( nReserve>=-1 && nReserve<=255 );
  sqlite3BtreeEnter(p);
  if( pBt->pageSizeFixed ){
    sqlite3BtreeLeave(p);
    return SQLITE_READONLY;
  }
  if( nReserve<0 ){
    nReserve = pBt->pageSize - pBt->usableSize;
  }
  assert( nReserve>=0 && nReserve<=255 );
  if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
        ((pageSize-1)&pageSize)==0 ){
    assert( (pageSize & 7)==0 );
    assert( !pBt->pPage1 && !pBt->pCursor );
    pBt->pageSize = pageSize;
    freeTempSpace(pBt);
    rc = sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize);
  }
  pBt->usableSize = pBt->pageSize - (u16)nReserve;
  sqlite3BtreeLeave(p);
  return rc;
}

/*
** Return the currently defined page size
*/
................................................................................
*/
int sqlite3BtreeSetAutoVacuum(Btree *p, int autoVacuum){
#ifdef SQLITE_OMIT_AUTOVACUUM
  return SQLITE_READONLY;
#else
  BtShared *pBt = p->pBt;
  int rc = SQLITE_OK;
  u8 av = autoVacuum ?1:0;

  sqlite3BtreeEnter(p);
  if( pBt->pageSizeFixed && av!=pBt->autoVacuum ){
    rc = SQLITE_READONLY;
  }else{
    pBt->autoVacuum = av;
  }
................................................................................
      /* After reading the first page of the database assuming a page size
      ** of BtShared.pageSize, we have discovered that the page-size is
      ** actually pageSize. Unlock the database, leave pBt->pPage1 at
      ** zero and return SQLITE_OK. The caller will call this function
      ** again with the correct page-size.
      */
      releasePage(pPage1);
      pBt->usableSize = (u16)usableSize;
      pBt->pageSize = (u16)pageSize;
      freeTempSpace(pBt);
      sqlite3PagerSetPagesize(pBt->pPager, &pBt->pageSize);
      return SQLITE_OK;
    }
    if( usableSize<500 ){
      goto page1_init_failed;
    }
................................................................................
  rc = sqlite3PagerWrite(pP1->pDbPage);
  if( rc ) return rc;
  memcpy(data, zMagicHeader, sizeof(zMagicHeader));
  assert( sizeof(zMagicHeader)==16 );
  put2byte(&data[16], pBt->pageSize);
  data[18] = 1;
  data[19] = 1;
  assert( pBt->usableSize<=pBt->pageSize && pBt->usableSize+255>=pBt->pageSize);
  data[20] = (u8)(pBt->pageSize - pBt->usableSize);
  data[21] = 64;
  data[22] = 32;
  data[23] = 32;
  memset(&data[24], 0, 100-24);
  zeroPage(pP1, PTF_INTKEY|PTF_LEAF|PTF_LEAFDATA );
  pBt->pageSizeFixed = 1;
#ifndef SQLITE_OMIT_AUTOVACUUM
................................................................................
** map entries for the overflow pages as well.
*/
static int setChildPtrmaps(MemPage *pPage){
  int i;                             /* Counter variable */
  int nCell;                         /* Number of cells in page pPage */
  int rc;                            /* Return code */
  BtShared *pBt = pPage->pBt;
  u8 isInitOrig = pPage->isInit;
  Pgno pgno = pPage->pgno;

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  rc = sqlite3BtreeInitPage(pPage);
  if( rc!=SQLITE_OK ){
    goto set_child_ptrmaps_out;
  }
................................................................................
  if( eType==PTRMAP_OVERFLOW2 ){
    /* The pointer is always the first 4 bytes of the page in this case.  */
    if( get4byte(pPage->aData)!=iFrom ){
      return SQLITE_CORRUPT_BKPT;
    }
    put4byte(pPage->aData, iTo);
  }else{
    u8 isInitOrig = pPage->isInit;
    int i;
    int nCell;

    sqlite3BtreeInitPage(pPage);
    nCell = pPage->nCell;

    for(i=0; i<nCell; i++){
................................................................................
  BtCursor *pCur                         /* Space for new cursor */
){
  int rc;
  Pgno nPage;
  BtShared *pBt = p->pBt;

  assert( sqlite3BtreeHoldsMutex(p) );
  assert( wrFlag==0 || wrFlag==1 );
  if( wrFlag ){
    if( pBt->readOnly ){
      return SQLITE_READONLY;
    }
    if( checkReadLocks(p, iTable, 0, 0) ){
      return SQLITE_LOCKED;
    }
................................................................................
  /* Now that no other errors can occur, finish filling in the BtCursor
  ** variables, link the cursor into the BtShared list and set *ppCur (the
  ** output argument to this function).
  */
  pCur->pKeyInfo = pKeyInfo;
  pCur->pBtree = p;
  pCur->pBt = pBt;
  pCur->wrFlag = (u8)wrFlag;
  pCur->pNext = pBt->pCursor;
  if( pCur->pNext ){
    pCur->pNext->pPrev = pCur;
  }
  pBt->pCursor = pCur;
  pCur->eState = CURSOR_INVALID;

................................................................................
  assert( pPage );
  assert( pCur->eState==CURSOR_VALID );
  assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
  assert( cursorHoldsMutex(pCur) );

  getCellInfo(pCur);
  aPayload = pCur->info.pCell + pCur->info.nHeader;
  nKey = (pPage->intKey ? 0 : (int)pCur->info.nKey);

  if( skipKey ){
    offset += nKey;
  }
  if( offset+amt > nKey+pCur->info.nData 
   || &aPayload[pCur->info.nLocal] > &pPage->aData[pBt->usableSize]
  ){
................................................................................
  assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
  getCellInfo(pCur);
  aPayload = pCur->info.pCell;
  aPayload += pCur->info.nHeader;
  if( pPage->intKey ){
    nKey = 0;
  }else{
    nKey = (int)pCur->info.nKey;
  }
  if( skipKey ){
    aPayload += nKey;
    nLocal = pCur->info.nLocal - nKey;
  }else{
    nLocal = pCur->info.nLocal;
    if( nLocal>nKey ){
................................................................................
      assert( pCur->apPage[pCur->iPage]->nCell==0 );
      *pRes = 1;
    }else{
      assert( pCur->eState==CURSOR_VALID );
      *pRes = 0;
      rc = moveToRightmost(pCur);
      getCellInfo(pCur);
      pCur->atLast = rc==SQLITE_OK ?1:0;
    }
  }
  return rc;
}

/* Move the cursor so that it points to an entry near the key 
** specified by pIdxKey or intKey.   Return a success code.
................................................................................
    lwr = 0;
    upr = pPage->nCell-1;
    if( !pPage->intKey && pIdxKey==0 ){
      rc = SQLITE_CORRUPT_BKPT;
      goto moveto_finish;
    }
    if( biasRight ){
      pCur->aiIdx[pCur->iPage] = (u16)upr;
    }else{
      pCur->aiIdx[pCur->iPage] = (u16)((upr+lwr)/2);
    }
    if( lwr<=upr ) for(;;){
      void *pCellKey;
      i64 nCellKey;
      int idx = pCur->aiIdx[pCur->iPage];
      pCur->info.nSize = 0;
      pCur->validNKey = 1;
................................................................................
          c = +1;
        }
      }else{
        int available;
        pCellKey = (void *)fetchPayload(pCur, &available, 0);
        nCellKey = pCur->info.nKey;
        if( available>=nCellKey ){
          c = sqlite3VdbeRecordCompare((int)nCellKey, pCellKey, pIdxKey);
        }else{
          pCellKey = sqlite3Malloc( (int)nCellKey );
          if( pCellKey==0 ){
            rc = SQLITE_NOMEM;
            goto moveto_finish;
          }
          rc = sqlite3BtreeKey(pCur, 0, (int)nCellKey, (void*)pCellKey);
          c = sqlite3VdbeRecordCompare(nCellKey, pCellKey, pIdxKey);
          sqlite3_free(pCellKey);
          if( rc ) goto moveto_finish;
        }
      }
      if( c==0 ){
        pCur->info.nKey = nCellKey;
................................................................................
      }else{
        upr = idx-1;
      }
      if( lwr>upr ){
        pCur->info.nKey = nCellKey;
        break;
      }
      pCur->aiIdx[pCur->iPage] = (u16)((lwr+upr)/2);
    }
    assert( lwr==upr+1 );
    assert( pPage->isInit );
    if( pPage->leaf ){
      chldPg = 0;
    }else if( lwr>=pPage->nCell ){
      chldPg = get4byte(&pPage->aData[pPage->hdrOffset+8]);
................................................................................
    }
    if( chldPg==0 ){
      assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
      if( pRes ) *pRes = c;
      rc = SQLITE_OK;
      goto moveto_finish;
    }
    pCur->aiIdx[pCur->iPage] = (u16)lwr;
    pCur->info.nSize = 0;
    pCur->validNKey = 0;
    rc = moveToChild(pCur, chldPg);
    if( rc ) goto moveto_finish;
  }
moveto_finish:
  return rc;
................................................................................
  int *pRes           /* Write search results here */
){
  int rc;                    /* Status code */
  UnpackedRecord *pIdxKey;   /* Unpacked index key */
  UnpackedRecord aSpace[16]; /* Temp space for pIdxKey - to avoid a malloc */

  if( pKey ){
    assert( nKey==(i64)(int)nKey );
    pIdxKey = sqlite3VdbeRecordUnpack(pCur->pKeyInfo, (int)nKey, pKey,
                                      aSpace, sizeof(aSpace));
    if( pIdxKey==0 ) return SQLITE_NOMEM;
  }else{
    pIdxKey = 0;
  }
  rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias, pRes);
  if( pKey ){
................................................................................
  
  /* Fill in the payload */
  nPayload = nData + nZero;
  if( pPage->intKey ){
    pSrc = pData;
    nSrc = nData;
    nData = 0;
  }else{ 
    /* TBD:  Perhaps raise SQLITE_CORRUPT if nKey is larger than 31 bits? */
    nPayload += (int)nKey;
    pSrc = pKey;
    nSrc = (int)nKey;
  }
  *pnSize = info.nSize;
  spaceLeft = info.nLocal;
  pPayload = &pCell[nHeader];
  pPrior = &pCell[info.iOverflow];

  while( nPayload>0 ){
    if( spaceLeft==0 ){

#ifndef SQLITE_OMIT_AUTOVACUUM
      Pgno pgnoPtrmap = pgnoOvfl; /* Overflow page pointer-map entry page */
      if( pBt->autoVacuum ){
        do{
          pgnoOvfl++;
        } while( 
          PTRMAP_ISPAGE(pBt, pgnoOvfl) || pgnoOvfl==PENDING_BYTE_PAGE(pBt) 
        );


      }

#endif
      rc = allocateBtreePage(pBt, &pOvfl, &pgnoOvfl, pgnoOvfl, 0);
#ifndef SQLITE_OMIT_AUTOVACUUM
      /* If the database supports auto-vacuum, and the second or subsequent
      ** overflow page is being allocated, add an entry to the pointer-map
      ** for that page now. 
      **
      ** If this is the first overflow page, then write a partial entry 
      ** to the pointer-map. If we write nothing to this pointer-map slot,
................................................................................
  int ins;          /* Index in data[] where new cell pointer is inserted */
  int hdr;          /* Offset into data[] of the page header */
  int cellOffset;   /* Address of first cell pointer in data[] */
  u8 *data;         /* The content of the whole page */
  u8 *ptr;          /* Used for moving information around in data[] */

  assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );
  assert( pPage->nCell<=MX_CELL(pPage->pBt) && MX_CELL(pPage->pBt)<=5460 );
  assert( pPage->nOverflow<=ArraySize(pPage->aOvfl) );
  assert( sz==cellSizePtr(pPage, pCell) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  if( pPage->nOverflow || sz+2>pPage->nFree ){
    if( pTemp ){
      memcpy(pTemp+nSkip, pCell+nSkip, sz-nSkip);
      pCell = pTemp;
    }
    j = pPage->nOverflow++;
    assert( j<(int)(sizeof(pPage->aOvfl)/sizeof(pPage->aOvfl[0])) );
    pPage->aOvfl[j].pCell = pCell;
    pPage->aOvfl[j].idx = (u16)i;
    pPage->nFree = 0;
  }else{
    int rc = sqlite3PagerWrite(pPage->pDbPage);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    assert( sqlite3PagerIswriteable(pPage->pDbPage) );
................................................................................
  int hdr;          /* Index of page header */
  int cellptr;      /* Address of next cell pointer */
  int cellbody;     /* Address of next cell body */
  u8 *data;         /* Data for the page */

  assert( pPage->nOverflow==0 );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( nCell>=0 && nCell<=MX_CELL(pPage->pBt) && MX_CELL(pPage->pBt)<=5460 );
  totalSize = 0;
  for(i=0; i<nCell; i++){
    totalSize += aSize[i];
  }
  assert( totalSize+2*nCell<=pPage->nFree );
  assert( pPage->nCell==0 );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
................................................................................
      put2byte(&data[cellptr], cellbody);
      memcpy(&data[cellbody], apCell[i], aSize[i]);
      cellptr += 2;
      cellbody += aSize[i];
    }
    assert( cellbody==pPage->pBt->usableSize );
  }
  pPage->nCell = (u16)nCell;
}

/*
** The following parameters determine how many adjacent pages get involved
** in a balancing operation.  NN is the number of neighbors on either side
** of the page that participate in the balancing operation.  NB is the
** total number of pages that participate, including the target page and
................................................................................
    int limit = pOld->nCell+pOld->nOverflow;
    for(j=0; j<limit; j++){
      assert( nCell<nMaxCells );
      apCell[nCell] = findOverflowCell(pOld, j);
      szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
      if( ISAUTOVACUUM ){
        int a;
        aFrom[nCell] = (u8)i;   assert( i>=0 && i<6 );
        for(a=0; a<pOld->nOverflow; a++){
          if( pOld->aOvfl[a].pCell==apCell[nCell] ){
            aFrom[nCell] = 0xFF;
            break;
          }
        }
      }
................................................................................
        assert( iSpace1<=pBt->pageSize );
        memcpy(pTemp, apDiv[i], sz);
        apCell[nCell] = pTemp+leafCorrection;
        if( ISAUTOVACUUM ){
          aFrom[nCell] = 0xFF;
        }
        dropCell(pParent, nxDiv, sz);
        assert( leafCorrection==0 || leafCorrection==4 );
        szCell[nCell] -= (u16)leafCorrection;
        assert( get4byte(pTemp)==pgnoOld[i] );
        if( !pOld->leaf ){
          assert( leafCorrection==0 );
          /* The right pointer of the child page pOld becomes the left
          ** pointer of the divider cell */
          memcpy(apCell[nCell], &pOld->aData[pOld->hdrOffset+8], 4);
        }else{
................................................................................
    rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
    if( rc==SQLITE_OK ){
      put4byte(&pP1[36 + idx*4], iMeta);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( idx==7 ){
        assert( pBt->autoVacuum || iMeta==0 );
        assert( iMeta==0 || iMeta==1 );
        pBt->incrVacuum = (u8)iMeta;
      }
#endif
    }
  }
  sqlite3BtreeLeave(p);
  return rc;
}
................................................................................
    /* Check payload overflow pages
    */
    sqlite3_snprintf(sizeof(zContext), zContext,
             "On tree page %d cell %d: ", iPage, i);
    pCell = findCell(pPage,i);
    sqlite3BtreeParseCellPtr(pPage, pCell, &info);
    sz = info.nData;
    if( !pPage->intKey ) sz += (int)info.nKey;
    assert( sz==info.nPayload );
    if( sz>info.nLocal ){
      int nPage = (sz - info.nLocal + usableSize - 5)/(usableSize - 4);
      Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pBt->autoVacuum ){
        checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, iPage, zContext);
................................................................................
  nToPage = pagerPagecount(pBtTo);
  nFromPage = pagerPagecount(pBtFrom);
  iSkip = PENDING_BYTE_PAGE(pBtTo);

  /* Variable nNewPage is the number of pages required to store the
  ** contents of pFrom using the current page-size of pTo.
  */
  nNewPage = (Pgno)
     (((i64)nFromPage*(i64)nFromPageSize+(i64)nToPageSize-1)/(i64)nToPageSize);

  for(i=1; rc==SQLITE_OK && (i<=nToPage || i<=nNewPage); i++){

    /* Journal the original page.
    **
    ** iSkip is the page number of the locking page (PENDING_BYTE_PAGE)
    ** in database *pTo (before the copy). This page is never written 
................................................................................

      for(
        iOff=(i-1)*nToPageSize; 
        rc==SQLITE_OK && iOff<i*nToPageSize; 
        iOff += nFromPageSize
      ){
        DbPage *pFromPage = 0;
        Pgno iFrom = (Pgno)(iOff/nFromPageSize)+1;

        if( iFrom==PENDING_BYTE_PAGE(pBtFrom) ){
          continue;
        }

        rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage);
        if( rc==SQLITE_OK ){
................................................................................
        i64 iOff;
        for(
          iOff=iPending; 
          rc==SQLITE_OK && iOff<(iPending+nToPageSize); 
          iOff += nFromPageSize
        ){
          DbPage *pFromPage = 0;
          Pgno iFrom = (Pgno)(iOff/nFromPageSize)+1;
  
          if( iFrom==PENDING_BYTE_PAGE(pBtFrom) || iFrom>nFromPage ){
            continue;
          }
  
          rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage);
          if( rc==SQLITE_OK ){

Changes to src/btreeInt.h.

5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
...
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
...
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
** 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: btreeInt.h,v 1.36 2008/11/19 10:22:33 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.
................................................................................
#ifndef SQLITE_OMIT_AUTOVACUUM
  u8 autoVacuum;        /* True if auto-vacuum is enabled */
  u8 incrVacuum;        /* True if incr-vacuum is enabled */
  Pgno nTrunc;          /* Non-zero if the db will be truncated (incr vacuum) */
#endif
  u16 pageSize;         /* Total number of bytes on a page */
  u16 usableSize;       /* Number of usable bytes on each page */
  int maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
  int minLocal;         /* Minimum local payload in non-LEAFDATA tables */
  int maxLeaf;          /* Maximum local payload in a LEAFDATA table */
  int minLeaf;          /* Minimum local payload in a LEAFDATA table */
  u8 inTransaction;     /* Transaction state */
  int nTransaction;     /* Number of open transactions (read + write) */
  void *pSchema;        /* Pointer to space allocated by sqlite3BtreeSchema() */
  void (*xFreeSchema)(void*);  /* Destructor for BtShared.pSchema */
  sqlite3_mutex *mutex; /* Non-recursive mutex required to access this struct */
#ifndef SQLITE_OMIT_SHARED_CACHE
  int nRef;             /* Number of references to this structure */
................................................................................
  StrAccum errMsg;  /* Accumulate the error message text here */
};

/*
** Read or write a two- and four-byte big-endian integer values.
*/
#define get2byte(x)   ((x)[0]<<8 | (x)[1])
#define put2byte(p,v) ((p)[0] = (v)>>8, (p)[1] = (v))
#define get4byte sqlite3Get4byte
#define put4byte sqlite3Put4byte

/*
** Internal routines that should be accessed by the btree layer only.
*/
int sqlite3BtreeGetPage(BtShared*, Pgno, MemPage**, int);







|







 







|
|
|
|







 







|







5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
...
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
...
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
** 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: btreeInt.h,v 1.37 2008/12/10 16:45:51 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.
................................................................................
#ifndef SQLITE_OMIT_AUTOVACUUM
  u8 autoVacuum;        /* True if auto-vacuum is enabled */
  u8 incrVacuum;        /* True if incr-vacuum is enabled */
  Pgno nTrunc;          /* Non-zero if the db will be truncated (incr vacuum) */
#endif
  u16 pageSize;         /* Total number of bytes on a page */
  u16 usableSize;       /* Number of usable bytes on each page */
  u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
  u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */
  u16 maxLeaf;          /* Maximum local payload in a LEAFDATA table */
  u16 minLeaf;          /* Minimum local payload in a LEAFDATA table */
  u8 inTransaction;     /* Transaction state */
  int nTransaction;     /* Number of open transactions (read + write) */
  void *pSchema;        /* Pointer to space allocated by sqlite3BtreeSchema() */
  void (*xFreeSchema)(void*);  /* Destructor for BtShared.pSchema */
  sqlite3_mutex *mutex; /* Non-recursive mutex required to access this struct */
#ifndef SQLITE_OMIT_SHARED_CACHE
  int nRef;             /* Number of references to this structure */
................................................................................
  StrAccum errMsg;  /* Accumulate the error message text here */
};

/*
** Read or write a two- and four-byte big-endian integer values.
*/
#define get2byte(x)   ((x)[0]<<8 | (x)[1])
#define put2byte(p,v) ((p)[0] = (u8)((v)>>8), (p)[1] = (u8)(v))
#define get4byte sqlite3Get4byte
#define put4byte sqlite3Put4byte

/*
** Internal routines that should be accessed by the btree layer only.
*/
int sqlite3BtreeGetPage(BtShared*, Pgno, MemPage**, int);

Changes to src/main.c.

10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
....
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209



1210
1211
1212
1213
1214
1215
1216
**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.516 2008/12/09 14:46:10 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif
................................................................................

/*
** Return UTF-8 encoded English language explanation of the most recent
** error.
*/
const char *sqlite3_errmsg(sqlite3 *db){
  const char *z;
  if( !db || db->mallocFailed ){
    return sqlite3ErrStr(SQLITE_NOMEM);
  }
  if( !sqlite3SafetyCheckSickOrOk(db) ){
    return sqlite3ErrStr(SQLITE_MISUSE);
  }



  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  z = (char*)sqlite3_value_text(db->pErr);
  assert( !db->mallocFailed );
  if( z==0 ){
    z = sqlite3ErrStr(db->errCode);
  }







|







 







|





>
>
>







10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
....
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.517 2008/12/10 16:45:51 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif
................................................................................

/*
** Return UTF-8 encoded English language explanation of the most recent
** error.
*/
const char *sqlite3_errmsg(sqlite3 *db){
  const char *z;
  if( !db ){
    return sqlite3ErrStr(SQLITE_NOMEM);
  }
  if( !sqlite3SafetyCheckSickOrOk(db) ){
    return sqlite3ErrStr(SQLITE_MISUSE);
  }
  if( db->mallocFailed ){
    return sqlite3ErrStr(SQLITE_NOMEM);
  }
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  z = (char*)sqlite3_value_text(db->pErr);
  assert( !db->mallocFailed );
  if( z==0 ){
    z = sqlite3ErrStr(db->errCode);
  }

Changes to src/pager.c.

14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
....
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.510 2008/11/29 22:49:23 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"

/*
** Macros for troubleshooting.  Normally turned off
*/
................................................................................
  return rc;
}

/*
** Return TRUE if the database file is opened read-only.  Return FALSE
** if the database is (in theory) writable.
*/
int sqlite3PagerIsreadonly(Pager *pPager){
  return pPager->readOnly;
}

/*
** Return the number of references to the pager.
*/
int sqlite3PagerRefcount(Pager *pPager){







|







 







|







14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
....
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.511 2008/12/10 16:45:51 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"

/*
** Macros for troubleshooting.  Normally turned off
*/
................................................................................
  return rc;
}

/*
** Return TRUE if the database file is opened read-only.  Return FALSE
** if the database is (in theory) writable.
*/
u8 sqlite3PagerIsreadonly(Pager *pPager){
  return pPager->readOnly;
}

/*
** Return the number of references to the pager.
*/
int sqlite3PagerRefcount(Pager *pPager){

Changes to src/pager.h.

9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
..
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem.  The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
**
** @(#) $Id: pager.h,v 1.87 2008/11/19 10:22:33 danielk1977 Exp $
*/

#ifndef _PAGER_H_
#define _PAGER_H_

/*
** If defined as non-zero, auto-vacuum is enabled by default. Otherwise
................................................................................
int sqlite3PagerWrite(DbPage*);
int sqlite3PagerPagecount(Pager*, int*);
int sqlite3PagerTruncate(Pager*,Pgno);
int sqlite3PagerBegin(DbPage*, int exFlag);
int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, Pgno, int);
int sqlite3PagerCommitPhaseTwo(Pager*);
int sqlite3PagerRollback(Pager*);
int sqlite3PagerIsreadonly(Pager*);
int sqlite3PagerStmtBegin(Pager*);
int sqlite3PagerStmtCommit(Pager*);
int sqlite3PagerStmtRollback(Pager*);
void sqlite3PagerDontRollback(DbPage*);
int sqlite3PagerDontWrite(DbPage*);
int sqlite3PagerRefcount(Pager*);
void sqlite3PagerSetSafetyLevel(Pager*,int,int);







|







 







|







9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
..
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem.  The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
**
** @(#) $Id: pager.h,v 1.88 2008/12/10 16:45:51 drh Exp $
*/

#ifndef _PAGER_H_
#define _PAGER_H_

/*
** If defined as non-zero, auto-vacuum is enabled by default. Otherwise
................................................................................
int sqlite3PagerWrite(DbPage*);
int sqlite3PagerPagecount(Pager*, int*);
int sqlite3PagerTruncate(Pager*,Pgno);
int sqlite3PagerBegin(DbPage*, int exFlag);
int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, Pgno, int);
int sqlite3PagerCommitPhaseTwo(Pager*);
int sqlite3PagerRollback(Pager*);
u8 sqlite3PagerIsreadonly(Pager*);
int sqlite3PagerStmtBegin(Pager*);
int sqlite3PagerStmtCommit(Pager*);
int sqlite3PagerStmtRollback(Pager*);
void sqlite3PagerDontRollback(DbPage*);
int sqlite3PagerDontWrite(DbPage*);
int sqlite3PagerRefcount(Pager*);
void sqlite3PagerSetSafetyLevel(Pager*,int,int);