summaryrefslogtreecommitdiffstats
path: root/kopete/plugins/statistics/sqlite/util.c
blob: 74ec89795febe6389c2f01ef6e810585493ffaee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
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
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
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
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
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
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id$
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

#if SQLITE_DEBUG>2 && defined(__GLIBC__)
#include <execinfo.h>
void print_stack_trace(){
  void *bt[30];
  int i;
  int n = backtrace(bt, 30);

  sqlite3DebugPrintf("STACK: ");
  for(i=0; i<n;i++){
    sqlite3DebugPrintf("%p ", bt[i]);
  }
  sqlite3DebugPrintf("\n");
}
#else
#define print_stack_trace()
#endif

/*
** If malloc() ever fails, this global variable gets set to 1.
** This causes the library to abort and never again function.
*/
int sqlite3_malloc_failed = 0;

/*
** If SQLITE_DEBUG is defined, then use versions of malloc() and
** free() that track memory usage and check for buffer overruns.
*/
#ifdef SQLITE_DEBUG

/*
** For keeping track of the number of mallocs and frees.   This
** is used to check for memory leaks.
*/
int sqlite3_nMalloc;         /* Number of sqliteMalloc() calls */
int sqlite3_nFree;           /* Number of sqliteFree() calls */
int sqlite3_iMallocFail;     /* Fail sqliteMalloc() after this many calls */
#if SQLITE_DEBUG>1
static int memcnt = 0;
#endif

/*
** Number of 32-bit guard words
*/
#define N_GUARD 1

/*
** Allocate new memory and set it to zero.  Return NULL if
** no memory is available.
*/
void *sqlite3Malloc_(int n, int bZero, char *zFile, int line){
  void *p;
  int *pi;
  int i, k;
  if( sqlite3_iMallocFail>=0 ){
    sqlite3_iMallocFail--;
    if( sqlite3_iMallocFail==0 ){
      sqlite3_malloc_failed++;
#if SQLITE_DEBUG>1
      fprintf(stderr,"**** failed to allocate %d bytes at %s:%d\n",
              n, zFile,line);
#endif
      sqlite3_iMallocFail--;
      return 0;
    }
  }
  if( n==0 ) return 0;
  k = (n+sizeof(int)-1)/sizeof(int);
  pi = malloc( (N_GUARD*2+1+k)*sizeof(int));
  if( pi==0 ){
    sqlite3_malloc_failed++;
    return 0;
  }
  sqlite3_nMalloc++;
  for(i=0; i<N_GUARD; i++) pi[i] = 0xdead1122;
  pi[N_GUARD] = n;
  for(i=0; i<N_GUARD; i++) pi[k+1+N_GUARD+i] = 0xdead3344;
  p = &pi[N_GUARD+1];
  memset(p, bZero==0, n);
#if SQLITE_DEBUG>1
  print_stack_trace();
  fprintf(stderr,"%06d malloc %d bytes at 0x%x from %s:%d\n",
      ++memcnt, n, (int)p, zFile,line);
#endif
  return p;
}

/*
** Check to see if the given pointer was obtained from sqliteMalloc()
** and is able to hold at least N bytes.  Raise an exception if this
** is not the case.
**
** This routine is used for testing purposes only.
*/
void sqlite3CheckMemory(void *p, int N){
  int *pi = p;
  int n, i, k;
  pi -= N_GUARD+1;
  for(i=0; i<N_GUARD; i++){
    assert( pi[i]==0xdead1122 );
  }
  n = pi[N_GUARD];
  assert( N>=0 && N<n );
  k = (n+sizeof(int)-1)/sizeof(int);
  for(i=0; i<N_GUARD; i++){
    assert( pi[k+N_GUARD+1+i]==0xdead3344 );
  }
}

/*
** Free memory previously obtained from sqliteMalloc()
*/
void sqlite3Free_(void *p, char *zFile, int line){
  if( p ){
    int *pi, i, k, n;
    pi = p;
    pi -= N_GUARD+1;
    sqlite3_nFree++;
    for(i=0; i<N_GUARD; i++){
      if( pi[i]!=0xdead1122 ){
        fprintf(stderr,"Low-end memory corruption at 0x%x\n", (int)p);
        return;
      }
    }
    n = pi[N_GUARD];
    k = (n+sizeof(int)-1)/sizeof(int);
    for(i=0; i<N_GUARD; i++){
      if( pi[k+N_GUARD+1+i]!=0xdead3344 ){
        fprintf(stderr,"High-end memory corruption at 0x%x\n", (int)p);
        return;
      }
    }
    memset(pi, 0xff, (k+N_GUARD*2+1)*sizeof(int));
#if SQLITE_DEBUG>1
    fprintf(stderr,"%06d free %d bytes at 0x%x from %s:%d\n",
         ++memcnt, n, (int)p, zFile,line);
#endif
    free(pi);
  }
}

/*
** Resize a prior allocation.  If p==0, then this routine
** works just like sqliteMalloc().  If n==0, then this routine
** works just like sqliteFree().
*/
void *sqlite3Realloc_(void *oldP, int n, char *zFile, int line){
  int *oldPi, *pi, i, k, oldN, oldK;
  void *p;
  if( oldP==0 ){
    return sqlite3Malloc_(n,1,zFile,line);
  }
  if( n==0 ){
    sqlite3Free_(oldP,zFile,line);
    return 0;
  }
  oldPi = oldP;
  oldPi -= N_GUARD+1;
  if( oldPi[0]!=0xdead1122 ){
    fprintf(stderr,"Low-end memory corruption in realloc at 0x%x\n", (int)oldP);
    return 0;
  }
  oldN = oldPi[N_GUARD];
  oldK = (oldN+sizeof(int)-1)/sizeof(int);
  for(i=0; i<N_GUARD; i++){
    if( oldPi[oldK+N_GUARD+1+i]!=0xdead3344 ){
      fprintf(stderr,"High-end memory corruption in realloc at 0x%x\n",
              (int)oldP);
      return 0;
    }
  }
  k = (n + sizeof(int) - 1)/sizeof(int);
  pi = malloc( (k+N_GUARD*2+1)*sizeof(int) );
  if( pi==0 ){
    sqlite3_malloc_failed++;
    return 0;
  }
  for(i=0; i<N_GUARD; i++) pi[i] = 0xdead1122;
  pi[N_GUARD] = n;
  for(i=0; i<N_GUARD; i++) pi[k+N_GUARD+1+i] = 0xdead3344;
  p = &pi[N_GUARD+1];
  memcpy(p, oldP, n>oldN ? oldN : n);
  if( n>oldN ){
    memset(&((char*)p)[oldN], 0x55, n-oldN);
  }
  memset(oldPi, 0xab, (oldK+N_GUARD+2)*sizeof(int));
  free(oldPi);
#if SQLITE_DEBUG>1
  print_stack_trace();
  fprintf(stderr,"%06d realloc %d to %d bytes at 0x%x to 0x%x at %s:%d\n",
    ++memcnt, oldN, n, (int)oldP, (int)p, zFile, line);
#endif
  return p;
}

/*
** Make a copy of a string in memory obtained from sqliteMalloc()
*/
char *sqlite3StrDup_(const char *z, char *zFile, int line){
  char *zNew;
  if( z==0 ) return 0;
  zNew = sqlite3Malloc_(strlen(z)+1, 0, zFile, line);
  if( zNew ) strcpy(zNew, z);
  return zNew;
}
char *sqlite3StrNDup_(const char *z, int n, char *zFile, int line){
  char *zNew;
  if( z==0 ) return 0;
  zNew = sqlite3Malloc_(n+1, 0, zFile, line);
  if( zNew ){
    memcpy(zNew, z, n);
    zNew[n] = 0;
  }
  return zNew;
}

/*
** A version of sqliteFree that is always a function, not a macro.
*/
void sqlite3FreeX(void *p){
  sqliteFree(p);
}
#endif /* SQLITE_DEBUG */

/*
** The following versions of malloc() and free() are for use in a
** normal build.
*/
#if !defined(SQLITE_DEBUG)

/*
** Allocate new memory and set it to zero.  Return NULL if
** no memory is available.  See also sqliteMallocRaw().
*/
void *sqlite3Malloc(int n){
  void *p;
  if( (p = malloc(n))==0 ){
    if( n>0 ) sqlite3_malloc_failed++;
  }else{
    memset(p, 0, n);
  }
  return p;
}

/*
** Allocate new memory but do not set it to zero.  Return NULL if
** no memory is available.  See also sqliteMalloc().
*/
void *sqlite3MallocRaw(int n){
  void *p;
  if( (p = malloc(n))==0 ){
    if( n>0 ) sqlite3_malloc_failed++;
  }
  return p;
}

/*
** Free memory previously obtained from sqliteMalloc()
*/
void sqlite3FreeX(void *p){
  if( p ){
    free(p);
  }
}

/*
** Resize a prior allocation.  If p==0, then this routine
** works just like sqliteMalloc().  If n==0, then this routine
** works just like sqliteFree().
*/
void *sqlite3Realloc(void *p, int n){
  void *p2;
  if( p==0 ){
    return sqliteMalloc(n);
  }
  if( n==0 ){
    sqliteFree(p);
    return 0;
  }
  p2 = realloc(p, n);
  if( p2==0 ){
    sqlite3_malloc_failed++;
  }
  return p2;
}

/*
** Make a copy of a string in memory obtained from sqliteMalloc()
*/
char *sqlite3StrDup(const char *z){
  char *zNew;
  if( z==0 ) return 0;
  zNew = sqliteMallocRaw(strlen(z)+1);
  if( zNew ) strcpy(zNew, z);
  return zNew;
}
char *sqlite3StrNDup(const char *z, int n){
  char *zNew;
  if( z==0 ) return 0;
  zNew = sqliteMallocRaw(n+1);
  if( zNew ){
    memcpy(zNew, z, n);
    zNew[n] = 0;
  }
  return zNew;
}
#endif /* !defined(SQLITE_DEBUG) */

/*
** Create a string from the 2nd and subsequent arguments (up to the
** first NULL argument), store the string in memory obtained from
** sqliteMalloc() and make the pointer indicated by the 1st argument
** point to that string.  The 1st argument must either be NULL or 
** point to memory obtained from sqliteMalloc().
*/
void sqlite3SetString(char **pz, const char *zFirst, ...){
  va_list ap;
  int nByte;
  const char *z;
  char *zResult;

  if( pz==0 ) return;
  nByte = strlen(zFirst) + 1;
  va_start(ap, zFirst);
  while( (z = va_arg(ap, const char*))!=0 ){
    nByte += strlen(z);
  }
  va_end(ap);
  sqliteFree(*pz);
  *pz = zResult = sqliteMallocRaw( nByte );
  if( zResult==0 ){
    return;
  }
  strcpy(zResult, zFirst);
  zResult += strlen(zResult);
  va_start(ap, zFirst);
  while( (z = va_arg(ap, const char*))!=0 ){
    strcpy(zResult, z);
    zResult += strlen(zResult);
  }
  va_end(ap);
#ifdef SQLITE_DEBUG
#if SQLITE_DEBUG>1
  fprintf(stderr,"string at 0x%x is %s\n", (int)*pz, *pz);
#endif
#endif
}

/*
** Set the most recent error code and error string for the sqlite
** handle "db". The error code is set to "err_code".
**
** If it is not NULL, string zFormat specifies the format of the
** error string in the style of the printf functions: The following
** format characters are allowed:
**
**      %s      Insert a string
**      %z      A string that should be freed after use
**      %d      Insert an integer
**      %T      Insert a token
**      %S      Insert the first element of a SrcList
**
** zFormat and any string tokens that follow it are assumed to be
** encoded in UTF-8.
**
** To clear the most recent error for slqite handle "db", sqlite3Error
** should be called with err_code set to SQLITE_OK and zFormat set
** to NULL.
*/
void sqlite3Error(sqlite3 *db, int err_code, const char *zFormat, ...){
  if( db && (db->pErr || (db->pErr = sqlite3ValueNew())) ){
    db->errCode = err_code;
    if( zFormat ){
      char *z;
      va_list ap;
      va_start(ap, zFormat);
      z = sqlite3VMPrintf(zFormat, ap);
      va_end(ap);
      sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, sqlite3FreeX);
    }else{
      sqlite3ValueSetStr(db->pErr, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
    }
  }
}

/*
** Add an error message to pParse->zErrMsg and increment pParse->nErr.
** The following formatting characters are allowed:
**
**      %s      Insert a string
**      %z      A string that should be freed after use
**      %d      Insert an integer
**      %T      Insert a token
**      %S      Insert the first element of a SrcList
**
** This function should be used to report any error that occurs whilst
** compiling an SQL statement (i.e. within sqlite3_prepare()). The
** last thing the sqlite3_prepare() function does is copy the error
** stored by this function into the database handle using sqlite3Error().
** Function sqlite3Error() should be used during statement execution
** (sqlite3_step() etc.).
*/
void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){
  va_list ap;
  pParse->nErr++;
  sqliteFree(pParse->zErrMsg);
  va_start(ap, zFormat);
  pParse->zErrMsg = sqlite3VMPrintf(zFormat, ap);
  va_end(ap);
}

/*
** Convert an SQL-style quoted string into a normal string by removing
** the quote characters.  The conversion is done in-place.  If the
** input does not begin with a quote character, then this routine
** is a no-op.
**
** 2002-Feb-14: This routine is extended to remove MS-Access style
** brackets from around identifers.  For example:  "[a-b-c]" becomes
** "a-b-c".
*/
void sqlite3Dequote(char *z){
  int quote;
  int i, j;
  if( z==0 ) return;
  quote = z[0];
  switch( quote ){
    case '\'':  break;
    case '"':   break;
    case '[':   quote = ']';  break;
    default:    return;
  }
  for(i=1, j=0; z[i]; i++){
    if( z[i]==quote ){
      if( z[i+1]==quote ){
        z[j++] = quote;
        i++;
      }else{
        z[j++] = 0;
        break;
      }
    }else{
      z[j++] = z[i];
    }
  }
}

/* An array to map all upper-case characters into their corresponding
** lower-case character. 
*/
const unsigned char sqlite3UpperToLower[] = {
      0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,
     18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
     36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
     54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 97, 98, 99,100,101,102,103,
    104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,
    122, 91, 92, 93, 94, 95, 96, 97, 98, 99,100,101,102,103,104,105,106,107,
    108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,
    126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
    144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,
    162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,
    180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,
    198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,
    216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,
    234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,
    252,253,254,255
};
#define UpperToLower sqlite3UpperToLower

/*
** This function computes a hash on the name of a keyword.
** Case is not significant.
*/
int sqlite3HashNoCase(const char *z, int n){
  int h = 0;
  if( n<=0 ) n = strlen(z);
  while( n > 0  ){
    h = (h<<3) ^ h ^ UpperToLower[(unsigned char)*z++];
    n--;
  }
  return h & 0x7fffffff;
}

/*
** Some systems have stricmp().  Others have strcasecmp().  Because
** there is no consistency, we will define our own.
*/
int sqlite3StrICmp(const char *zLeft, const char *zRight){
  register unsigned char *a, *b;
  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return UpperToLower[*a] - UpperToLower[*b];
}
int sqlite3StrNICmp(const char *zLeft, const char *zRight, int N){
  register unsigned char *a, *b;
  a = (unsigned char *)zLeft;
  b = (unsigned char *)zRight;
  while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
  return N<0 ? 0 : UpperToLower[*a] - UpperToLower[*b];
}

/*
** Return TRUE if z is a pure numeric string.  Return FALSE if the
** string contains any character which is not part of a number. If
** the string is numeric and contains the '.' character, set *realnum
** to TRUE (otherwise FALSE).
**
** An empty string is considered non-numeric.
*/
int sqlite3IsNumber(const char *z, int *realnum, u8 enc){
  int incr = (enc==SQLITE_UTF8?1:2);
  if( enc==SQLITE_UTF16BE ) z++;
  if( *z=='-' || *z=='+' ) z += incr;
  if( !isdigit(*(u8*)z) ){
    return 0;
  }
  z += incr;
  if( realnum ) *realnum = 0;
  while( isdigit(*(u8*)z) ){ z += incr; }
  if( *z=='.' ){
    z += incr;
    if( !isdigit(*(u8*)z) ) return 0;
    while( isdigit(*(u8*)z) ){ z += incr; }
    if( realnum ) *realnum = 1;
  }
  if( *z=='e' || *z=='E' ){
    z += incr;
    if( *z=='+' || *z=='-' ) z += incr;
    if( !isdigit(*(u8*)z) ) return 0;
    while( isdigit(*(u8*)z) ){ z += incr; }
    if( realnum ) *realnum = 1;
  }
  return *z==0;
}

/*
** The string z[] is an ascii representation of a real number.
** Convert this string to a double.
**
** This routine assumes that z[] really is a valid number.  If it
** is not, the result is undefined.
**
** This routine is used instead of the library atof() function because
** the library atof() might want to use "," as the decimal point instead
** of "." depending on how locale is set.  But that would cause problems
** for SQL.  So this routine always uses "." regardless of locale.
*/
double sqlite3AtoF(const char *z, const char **pzEnd){
  int sign = 1;
  LONGDOUBLE_TYPE v1 = 0.0;
  if( *z=='-' ){
    sign = -1;
    z++;
  }else if( *z=='+' ){
    z++;
  }
  while( isdigit(*(u8*)z) ){
    v1 = v1*10.0 + (*z - '0');
    z++;
  }
  if( *z=='.' ){
    LONGDOUBLE_TYPE divisor = 1.0;
    z++;
    while( isdigit(*(u8*)z) ){
      v1 = v1*10.0 + (*z - '0');
      divisor *= 10.0;
      z++;
    }
    v1 /= divisor;
  }
  if( *z=='e' || *z=='E' ){
    int esign = 1;
    int eval = 0;
    LONGDOUBLE_TYPE scale = 1.0;
    z++;
    if( *z=='-' ){
      esign = -1;
      z++;
    }else if( *z=='+' ){
      z++;
    }
    while( isdigit(*(u8*)z) ){
      eval = eval*10 + *z - '0';
      z++;
    }
    while( eval>=64 ){ scale *= 1.0e+64; eval -= 64; }
    while( eval>=16 ){ scale *= 1.0e+16; eval -= 16; }
    while( eval>=4 ){ scale *= 1.0e+4; eval -= 4; }
    while( eval>=1 ){ scale *= 1.0e+1; eval -= 1; }
    if( esign<0 ){
      v1 /= scale;
    }else{
      v1 *= scale;
    }
  }
  if( pzEnd ) *pzEnd = z;
  return sign<0 ? -v1 : v1;
}

/*
** Return TRUE if zNum is a 64-bit signed integer and write
** the value of the integer into *pNum.  If zNum is not an integer
** or is an integer that is too large to be expressed with 64 bits,
** then return false.  If n>0 and the integer is string is not
** exactly n bytes long, return false.
**
** When this routine was originally written it dealt with only
** 32-bit numbers.  At that time, it was much faster than the
** atoi() library routine in RedHat 7.2.
*/
int sqlite3atoi64(const char *zNum, i64 *pNum){
  i64 v = 0;
  int neg;
  int i, c;
  if( *zNum=='-' ){
    neg = 1;
    zNum++;
  }else if( *zNum=='+' ){
    neg = 0;
    zNum++;
  }else{
    neg = 0;
  }
  for(i=0; (c=zNum[i])>='0' && c<='9'; i++){
    v = v*10 + c - '0';
  }
  *pNum = neg ? -v : v;
  return c==0 && i>0 && 
      (i<19 || (i==19 && memcmp(zNum,"9223372036854775807",19)<=0));
}

/*
** The string zNum represents an integer.  There might be some other
** information following the integer too, but that part is ignored.
** If the integer that the prefix of zNum represents will fit in a
** 32-bit signed integer, return TRUE.  Otherwise return FALSE.
**
** This routine returns FALSE for the string -2147483648 even that
** that number will in fact fit in a 32-bit integer.  But positive
** 2147483648 will not fit in 32 bits.  So it seems safer to return
** false.
*/
static int sqlite3FitsIn32Bits(const char *zNum){
  int i, c;
  if( *zNum=='-' || *zNum=='+' ) zNum++;
  for(i=0; (c=zNum[i])>='0' && c<='9'; i++){}
  return i<10 || (i==10 && memcmp(zNum,"2147483647",10)<=0);
}

/*
** If zNum represents an integer that will fit in 32-bits, then set
** *pValue to that integer and return true.  Otherwise return false.
*/
int sqlite3GetInt32(const char *zNum, int *pValue){
  if( sqlite3FitsIn32Bits(zNum) ){
    *pValue = atoi(zNum);
    return 1;
  }
  return 0;
}

/*
** The string zNum represents an integer.  There might be some other
** information following the integer too, but that part is ignored.
** If the integer that the prefix of zNum represents will fit in a
** 64-bit signed integer, return TRUE.  Otherwise return FALSE.
**
** This routine returns FALSE for the string -9223372036854775808 even that
** that number will, in theory fit in a 64-bit integer.  Positive
** 9223373036854775808 will not fit in 64 bits.  So it seems safer to return
** false.
*/
int sqlite3FitsIn64Bits(const char *zNum){
  int i, c;
  if( *zNum=='-' || *zNum=='+' ) zNum++;
  for(i=0; (c=zNum[i])>='0' && c<='9'; i++){}
  return i<19 || (i==19 && memcmp(zNum,"9223372036854775807",19)<=0);
}


/*
** Change the sqlite.magic from SQLITE_MAGIC_OPEN to SQLITE_MAGIC_BUSY.
** Return an error (non-zero) if the magic was not SQLITE_MAGIC_OPEN
** when this routine is called.
**
** This routine is a attempt to detect if two threads use the
** same sqlite* pointer at the same time.  There is a race 
** condition so it is possible that the error is not detected.
** But usually the problem will be seen.  The result will be an
** error which can be used to debug the application that is
** using SQLite incorrectly.
**
** Ticket #202:  If db->magic is not a valid open value, take care not
** to modify the db structure at all.  It could be that db is a stale
** pointer.  In other words, it could be that there has been a prior
** call to sqlite3_close(db) and db has been deallocated.  And we do
** not want to write into deallocated memory.
*/
int sqlite3SafetyOn(sqlite3 *db){
  if( db->magic==SQLITE_MAGIC_OPEN ){
    db->magic = SQLITE_MAGIC_BUSY;
    return 0;
  }else if( db->magic==SQLITE_MAGIC_BUSY || db->magic==SQLITE_MAGIC_ERROR ){
    db->magic = SQLITE_MAGIC_ERROR;
    db->flags |= SQLITE_Interrupt;
  }
  return 1;
}

/*
** Change the magic from SQLITE_MAGIC_BUSY to SQLITE_MAGIC_OPEN.
** Return an error (non-zero) if the magic was not SQLITE_MAGIC_BUSY
** when this routine is called.
*/
int sqlite3SafetyOff(sqlite3 *db){
  if( db->magic==SQLITE_MAGIC_BUSY ){
    db->magic = SQLITE_MAGIC_OPEN;
    return 0;
  }else if( db->magic==SQLITE_MAGIC_OPEN || db->magic==SQLITE_MAGIC_ERROR ){
    db->magic = SQLITE_MAGIC_ERROR;
    db->flags |= SQLITE_Interrupt;
  }
  return 1;
}

/*
** Check to make sure we have a valid db pointer.  This test is not
** foolproof but it does provide some measure of protection against
** misuse of the interface such as passing in db pointers that are
** NULL or which have been previously closed.  If this routine returns
** TRUE it means that the db pointer is invalid and should not be
** dereferenced for any reason.  The calling function should invoke
** SQLITE_MISUSE immediately.
*/
int sqlite3SafetyCheck(sqlite3 *db){
  int magic;
  if( db==0 ) return 1;
  magic = db->magic;
  if( magic!=SQLITE_MAGIC_CLOSED &&
         magic!=SQLITE_MAGIC_OPEN &&
         magic!=SQLITE_MAGIC_BUSY ) return 1;
  return 0;
}

/*
** The variable-length integer encoding is as follows:
**
** KEY:
**         A = 0xxxxxxx    7 bits of data and one flag bit
**         B = 1xxxxxxx    7 bits of data and one flag bit
**         C = xxxxxxxx    8 bits of data
**
**  7 bits - A
** 14 bits - BA
** 21 bits - BBA
** 28 bits - BBBA
** 35 bits - BBBBA
** 42 bits - BBBBBA
** 49 bits - BBBBBBA
** 56 bits - BBBBBBBA
** 64 bits - BBBBBBBBC
*/

/*
** Write a 64-bit variable-length integer to memory starting at p[0].
** The length of data write will be between 1 and 9 bytes.  The number
** of bytes written is returned.
**
** A variable-length integer consists of the lower 7 bits of each byte
** for all bytes that have the 8th bit set and one byte with the 8th
** bit clear.  Except, if we get to the 9th byte, it stores the full
** 8 bits and is the last byte.
*/
int sqlite3PutVarint(unsigned char *p, u64 v){
  int i, j, n;
  u8 buf[10];
  if( v & 0xff00000000000000 ){
    p[8] = v;
    v >>= 8;
    for(i=7; i>=0; i--){
      p[i] = (v & 0x7f) | 0x80;
      v >>= 7;
    }
    return 9;
  }    
  n = 0;
  do{
    buf[n++] = (v & 0x7f) | 0x80;
    v >>= 7;
  }while( v!=0 );
  buf[0] &= 0x7f;
  assert( n<=9 );
  for(i=0, j=n-1; j>=0; j--, i++){
    p[i] = buf[j];
  }
  return n;
}

/*
** Read a 64-bit variable-length integer from memory starting at p[0].
** Return the number of bytes read.  The value is stored in *v.
*/
int sqlite3GetVarint(const unsigned char *p, u64 *v){
  u32 x;
  u64 x64;
  int n;
  unsigned char c;
  if( ((c = p[0]) & 0x80)==0 ){
    *v = c;
    return 1;
  }
  x = c & 0x7f;
  if( ((c = p[1]) & 0x80)==0 ){
    *v = (x<<7) | c;
    return 2;
  }
  x = (x<<7) | (c&0x7f);
  if( ((c = p[2]) & 0x80)==0 ){
    *v = (x<<7) | c;
    return 3;
  }
  x = (x<<7) | (c&0x7f);
  if( ((c = p[3]) & 0x80)==0 ){
    *v = (x<<7) | c;
    return 4;
  }
  x64 = (x<<7) | (c&0x7f);
  n = 4;
  do{
    c = p[n++];
    if( n==9 ){
      x64 = (x64<<8) | c;
      break;
    }
    x64 = (x64<<7) | (c&0x7f);
  }while( (c & 0x80)!=0 );
  *v = x64;
  return n;
}

/*
** Read a 32-bit variable-length integer from memory starting at p[0].
** Return the number of bytes read.  The value is stored in *v.
*/
int sqlite3GetVarint32(const unsigned char *p, u32 *v){
  u32 x;
  int n;
  unsigned char c;
  if( ((c = p[0]) & 0x80)==0 ){
    *v = c;
    return 1;
  }
  x = c & 0x7f;
  if( ((c = p[1]) & 0x80)==0 ){
    *v = (x<<7) | c;
    return 2;
  }
  x = (x<<7) | (c & 0x7f);
  n = 2;
  do{
    x = (x<<7) | ((c = p[n++])&0x7f);
  }while( (c & 0x80)!=0 && n<9 );
  *v = x;
  return n;
}

/*
** Return the number of bytes that will be needed to store the given
** 64-bit integer.
*/
int sqlite3VarintLen(u64 v){
  int i = 0;
  do{
    i++;
    v >>= 7;
  }while( v!=0 && i<9 );
  return i;
}

/*
** Translate a single byte of Hex into an integer.
*/
static int hexToInt(int h){
  if( h>='0' && h<='9' ){
    return h - '0';
  }else if( h>='a' && h<='f' ){
    return h - 'a' + 10;
  }else if( h>='A' && h<='F' ){
    return h - 'A' + 10;
  }else{
    return 0;
  }
}

/*
** Convert a BLOB literal of the form "x'hhhhhh'" into its binary
** value.  Return a pointer to its binary value.  Space to hold the
** binary value has been obtained from malloc and must be freed by
** the calling routine.
*/
void *sqlite3HexToBlob(const char *z){
  char *zBlob;
  int i;
  int n = strlen(z);
  if( n%2 ) return 0;

  zBlob = (char *)sqliteMalloc(n/2);
  for(i=0; i<n; i+=2){
    zBlob[i/2] = (hexToInt(z[i])<<4) | hexToInt(z[i+1]);
  }
  return zBlob;
}

#if defined(SQLITE_TEST)
/*
** Convert text generated by the "%p" conversion format back into
** a pointer.
*/
void *sqlite3TextToPtr(const char *z){
  void *p;
  u64 v;
  u32 v2;
  if( z[0]=='0' && z[1]=='x' ){
    z += 2;
  }
  v = 0;
  while( *z ){
    v = (v<<4) + hexToInt(*z);
    z++;
  }
  if( sizeof(p)==sizeof(v) ){
    p = *(void**)&v;
  }else{
    assert( sizeof(p)==sizeof(v2) );
    v2 = (u32)v;
    p = *(void**)&v2;
  }
  return p;
}
#endif