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1/*
2** 2001 September 15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** Utility functions used throughout sqlite.
13**
14** This file contains functions for allocating memory, comparing
15** strings, and stuff like that.
16**
17** $Id: util.c,v 1.212 2007/09/01 10:01:13 danielk1977 Exp $
18*/
19#include "sqliteInt.h"
20#include <stdarg.h>
21#include <ctype.h>
22
23
24/*
25** Set the most recent error code and error string for the sqlite
26** handle "db". The error code is set to "err_code".
27**
28** If it is not NULL, string zFormat specifies the format of the
29** error string in the style of the printf functions: The following
30** format characters are allowed:
31**
32** %s Insert a string
33** %z A string that should be freed after use
34** %d Insert an integer
35** %T Insert a token
36** %S Insert the first element of a SrcList
37**
38** zFormat and any string tokens that follow it are assumed to be
39** encoded in UTF-8.
40**
41** To clear the most recent error for sqlite handle "db", sqlite3Error
42** should be called with err_code set to SQLITE_OK and zFormat set
43** to NULL.
44*/
45void sqlite3Error(sqlite3 *db, int err_code, const char *zFormat, ...){
46 if( db && (db->pErr || (db->pErr = sqlite3ValueNew(db))!=0) ){
47 db->errCode = err_code;
48 if( zFormat ){
49 char *z;
50 va_list ap;
51 va_start(ap, zFormat);
52 z = sqlite3VMPrintf(db, zFormat, ap);
53 va_end(ap);
54 sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, sqlite3_free);
55 }else{
56 sqlite3ValueSetStr(db->pErr, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
57 }
58 }
59}
60
61/*
62** Add an error message to pParse->zErrMsg and increment pParse->nErr.
63** The following formatting characters are allowed:
64**
65** %s Insert a string
66** %z A string that should be freed after use
67** %d Insert an integer
68** %T Insert a token
69** %S Insert the first element of a SrcList
70**
71** This function should be used to report any error that occurs whilst
72** compiling an SQL statement (i.e. within sqlite3_prepare()). The
73** last thing the sqlite3_prepare() function does is copy the error
74** stored by this function into the database handle using sqlite3Error().
75** Function sqlite3Error() should be used during statement execution
76** (sqlite3_step() etc.).
77*/
78void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){
79 va_list ap;
80 pParse->nErr++;
81 sqlite3_free(pParse->zErrMsg);
82 va_start(ap, zFormat);
83 pParse->zErrMsg = sqlite3VMPrintf(pParse->db, zFormat, ap);
84 va_end(ap);
85 if( pParse->rc==SQLITE_OK ){
86 pParse->rc = SQLITE_ERROR;
87 }
88}
89
90/*
91** Clear the error message in pParse, if any
92*/
93void sqlite3ErrorClear(Parse *pParse){
94 sqlite3_free(pParse->zErrMsg);
95 pParse->zErrMsg = 0;
96 pParse->nErr = 0;
97}
98
99/*
100** Convert an SQL-style quoted string into a normal string by removing
101** the quote characters. The conversion is done in-place. If the
102** input does not begin with a quote character, then this routine
103** is a no-op.
104**
105** 2002-Feb-14: This routine is extended to remove MS-Access style
106** brackets from around identifers. For example: "[a-b-c]" becomes
107** "a-b-c".
108*/
109void sqlite3Dequote(char *z){
110 int quote;
111 int i, j;
112 if( z==0 ) return;
113 quote = z[0];
114 switch( quote ){
115 case '\'': break;
116 case '"': break;
117 case '`': break; /* For MySQL compatibility */
118 case '[': quote = ']'; break; /* For MS SqlServer compatibility */
119 default: return;
120 }
121 for(i=1, j=0; z[i]; i++){
122 if( z[i]==quote ){
123 if( z[i+1]==quote ){
124 z[j++] = quote;
125 i++;
126 }else{
127 z[j++] = 0;
128 break;
129 }
130 }else{
131 z[j++] = z[i];
132 }
133 }
134}
135
136/* An array to map all upper-case characters into their corresponding
137** lower-case character.
138*/
139const unsigned char sqlite3UpperToLower[] = {
140#ifdef SQLITE_ASCII
141 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
142 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
143 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
144 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 97, 98, 99,100,101,102,103,
145 104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,
146 122, 91, 92, 93, 94, 95, 96, 97, 98, 99,100,101,102,103,104,105,106,107,
147 108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,
148 126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
149 144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,
150 162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,
151 180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,
152 198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,
153 216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,
154 234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,
155 252,253,254,255
156#endif
157#ifdef SQLITE_EBCDIC
158 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, /* 0x */
159 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, /* 1x */
160 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, /* 2x */
161 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, /* 3x */
162 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, /* 4x */
163 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, /* 5x */
164 96, 97, 66, 67, 68, 69, 70, 71, 72, 73,106,107,108,109,110,111, /* 6x */
165 112, 81, 82, 83, 84, 85, 86, 87, 88, 89,122,123,124,125,126,127, /* 7x */
166 128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143, /* 8x */
167 144,145,146,147,148,149,150,151,152,153,154,155,156,157,156,159, /* 9x */
168 160,161,162,163,164,165,166,167,168,169,170,171,140,141,142,175, /* Ax */
169 176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191, /* Bx */
170 192,129,130,131,132,133,134,135,136,137,202,203,204,205,206,207, /* Cx */
171 208,145,146,147,148,149,150,151,152,153,218,219,220,221,222,223, /* Dx */
172 224,225,162,163,164,165,166,167,168,169,232,203,204,205,206,207, /* Ex */
173 239,240,241,242,243,244,245,246,247,248,249,219,220,221,222,255, /* Fx */
174#endif
175};
176#define UpperToLower sqlite3UpperToLower
177
178/*
179** Some systems have stricmp(). Others have strcasecmp(). Because
180** there is no consistency, we will define our own.
181*/
182int sqlite3StrICmp(const char *zLeft, const char *zRight){
183 register unsigned char *a, *b;
184 a = (unsigned char *)zLeft;
185 b = (unsigned char *)zRight;
186 while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
187 return UpperToLower[*a] - UpperToLower[*b];
188}
189int sqlite3StrNICmp(const char *zLeft, const char *zRight, int N){
190 register unsigned char *a, *b;
191 a = (unsigned char *)zLeft;
192 b = (unsigned char *)zRight;
193 while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
194 return N<0 ? 0 : UpperToLower[*a] - UpperToLower[*b];
195}
196
197/*
198** Return TRUE if z is a pure numeric string. Return FALSE if the
199** string contains any character which is not part of a number. If
200** the string is numeric and contains the '.' character, set *realnum
201** to TRUE (otherwise FALSE).
202**
203** An empty string is considered non-numeric.
204*/
205int sqlite3IsNumber(const char *z, int *realnum, u8 enc){
206 int incr = (enc==SQLITE_UTF8?1:2);
207 if( enc==SQLITE_UTF16BE ) z++;
208 if( *z=='-' || *z=='+' ) z += incr;
209 if( !isdigit(*(u8*)z) ){
210 return 0;
211 }
212 z += incr;
213 if( realnum ) *realnum = 0;
214 while( isdigit(*(u8*)z) ){ z += incr; }
215 if( *z=='.' ){
216 z += incr;
217 if( !isdigit(*(u8*)z) ) return 0;
218 while( isdigit(*(u8*)z) ){ z += incr; }
219 if( realnum ) *realnum = 1;
220 }
221 if( *z=='e' || *z=='E' ){
222 z += incr;
223 if( *z=='+' || *z=='-' ) z += incr;
224 if( !isdigit(*(u8*)z) ) return 0;
225 while( isdigit(*(u8*)z) ){ z += incr; }
226 if( realnum ) *realnum = 1;
227 }
228 return *z==0;
229}
230
231/*
232** The string z[] is an ascii representation of a real number.
233** Convert this string to a double.
234**
235** This routine assumes that z[] really is a valid number. If it
236** is not, the result is undefined.
237**
238** This routine is used instead of the library atof() function because
239** the library atof() might want to use "," as the decimal point instead
240** of "." depending on how locale is set. But that would cause problems
241** for SQL. So this routine always uses "." regardless of locale.
242*/
243int sqlite3AtoF(const char *z, double *pResult){
244#ifndef SQLITE_OMIT_FLOATING_POINT
245 int sign = 1;
246 const char *zBegin = z;
247 LONGDOUBLE_TYPE v1 = 0.0;
248 while( isspace(*(u8*)z) ) z++;
249 if( *z=='-' ){
250 sign = -1;
251 z++;
252 }else if( *z=='+' ){
253 z++;
254 }
255 while( isdigit(*(u8*)z) ){
256 v1 = v1*10.0 + (*z - '0');
257 z++;
258 }
259 if( *z=='.' ){
260 LONGDOUBLE_TYPE divisor = 1.0;
261 z++;
262 while( isdigit(*(u8*)z) ){
263 v1 = v1*10.0 + (*z - '0');
264 divisor *= 10.0;
265 z++;
266 }
267 v1 /= divisor;
268 }
269 if( *z=='e' || *z=='E' ){
270 int esign = 1;
271 int eval = 0;
272 LONGDOUBLE_TYPE scale = 1.0;
273 z++;
274 if( *z=='-' ){
275 esign = -1;
276 z++;
277 }else if( *z=='+' ){
278 z++;
279 }
280 while( isdigit(*(u8*)z) ){
281 eval = eval*10 + *z - '0';
282 z++;
283 }
284 while( eval>=64 ){ scale *= 1.0e+64; eval -= 64; }
285 while( eval>=16 ){ scale *= 1.0e+16; eval -= 16; }
286 while( eval>=4 ){ scale *= 1.0e+4; eval -= 4; }
287 while( eval>=1 ){ scale *= 1.0e+1; eval -= 1; }
288 if( esign<0 ){
289 v1 /= scale;
290 }else{
291 v1 *= scale;
292 }
293 }
294 *pResult = sign<0 ? -v1 : v1;
295 return z - zBegin;
296#else
297 return sqlite3Atoi64(z, pResult);
298#endif /* SQLITE_OMIT_FLOATING_POINT */
299}
300
301/*
302** Compare the 19-character string zNum against the text representation
303** value 2^63: 9223372036854775808. Return negative, zero, or positive
304** if zNum is less than, equal to, or greater than the string.
305**
306** Unlike memcmp() this routine is guaranteed to return the difference
307** in the values of the last digit if the only difference is in the
308** last digit. So, for example,
309**
310** compare2pow63("9223372036854775800")
311**
312** will return -8.
313*/
314static int compare2pow63(const char *zNum){
315 int c;
316 c = memcmp(zNum,"922337203685477580",18);
317 if( c==0 ){
318 c = zNum[18] - '8';
319 }
320 return c;
321}
322
323
324/*
325** Return TRUE if zNum is a 64-bit signed integer and write
326** the value of the integer into *pNum. If zNum is not an integer
327** or is an integer that is too large to be expressed with 64 bits,
328** then return false.
329**
330** When this routine was originally written it dealt with only
331** 32-bit numbers. At that time, it was much faster than the
332** atoi() library routine in RedHat 7.2.
333*/
334int sqlite3Atoi64(const char *zNum, i64 *pNum){
335 i64 v = 0;
336 int neg;
337 int i, c;
338 while( isspace(*(u8*)zNum) ) zNum++;
339 if( *zNum=='-' ){
340 neg = 1;
341 zNum++;
342 }else if( *zNum=='+' ){
343 neg = 0;
344 zNum++;
345 }else{
346 neg = 0;
347 }
348 while( zNum[0]=='0' ){ zNum++; } /* Skip over leading zeros. Ticket #2454 */
349 for(i=0; (c=zNum[i])>='0' && c<='9'; i++){
350 v = v*10 + c - '0';
351 }
352 *pNum = neg ? -v : v;
353 if( c!=0 || i==0 || i>19 ){
354 /* zNum is empty or contains non-numeric text or is longer
355 ** than 19 digits (thus guaranting that it is too large) */
356 return 0;
357 }else if( i<19 ){
358 /* Less than 19 digits, so we know that it fits in 64 bits */
359 return 1;
360 }else{
361 /* 19-digit numbers must be no larger than 9223372036854775807 if positive
362 ** or 9223372036854775808 if negative. Note that 9223372036854665808
363 ** is 2^63. */
364 return compare2pow63(zNum)<neg;
365 }
366}
367
368/*
369** The string zNum represents an integer. There might be some other
370** information following the integer too, but that part is ignored.
371** If the integer that the prefix of zNum represents will fit in a
372** 64-bit signed integer, return TRUE. Otherwise return FALSE.
373**
374** This routine returns FALSE for the string -9223372036854775808 even that
375** that number will, in theory fit in a 64-bit integer. Positive
376** 9223373036854775808 will not fit in 64 bits. So it seems safer to return
377** false.
378*/
379int sqlite3FitsIn64Bits(const char *zNum){
380 int i, c;
381 int neg = 0;
382 if( *zNum=='-' ){
383 neg = 1;
384 zNum++;
385 }else if( *zNum=='+' ){
386 zNum++;
387 }
388 while( *zNum=='0' ){
389 zNum++; /* Skip leading zeros. Ticket #2454 */
390 }
391 for(i=0; (c=zNum[i])>='0' && c<='9'; i++){}
392 if( i<19 ){
393 /* Guaranteed to fit if less than 19 digits */
394 return 1;
395 }else if( i>19 ){
396 /* Guaranteed to be too big if greater than 19 digits */
397 return 0;
398 }else{
399 /* Compare against 2^63. */
400 return compare2pow63(zNum)<neg;
401 }
402}
403
404/*
405** If zNum represents an integer that will fit in 32-bits, then set
406** *pValue to that integer and return true. Otherwise return false.
407**
408** Any non-numeric characters that following zNum are ignored.
409** This is different from sqlite3Atoi64() which requires the
410** input number to be zero-terminated.
411*/
412int sqlite3GetInt32(const char *zNum, int *pValue){
413 sqlite_int64 v = 0;
414 int i, c;
415 int neg = 0;
416 if( zNum[0]=='-' ){
417 neg = 1;
418 zNum++;
419 }else if( zNum[0]=='+' ){
420 zNum++;
421 }
422 while( zNum[0]=='0' ) zNum++;
423 for(i=0; i<11 && (c = zNum[i] - '0')>=0 && c<=9; i++){
424 v = v*10 + c;
425 }
426
427 /* The longest decimal representation of a 32 bit integer is 10 digits:
428 **
429 ** 1234567890
430 ** 2^31 -> 2147483648
431 */
432 if( i>10 ){
433 return 0;
434 }
435 if( v-neg>2147483647 ){
436 return 0;
437 }
438 if( neg ){
439 v = -v;
440 }
441 *pValue = (int)v;
442 return 1;
443}
444
445/*
446** Check to make sure we have a valid db pointer. This test is not
447** foolproof but it does provide some measure of protection against
448** misuse of the interface such as passing in db pointers that are
449** NULL or which have been previously closed. If this routine returns
450** TRUE it means that the db pointer is invalid and should not be
451** dereferenced for any reason. The calling function should invoke
452** SQLITE_MISUSE immediately.
453*/
454int sqlite3SafetyCheck(sqlite3 *db){
455 int magic;
456 if( db==0 ) return 1;
457 magic = db->magic;
458 if( magic!=SQLITE_MAGIC_CLOSED &&
459 magic!=SQLITE_MAGIC_OPEN &&
460 magic!=SQLITE_MAGIC_BUSY ) return 1;
461 return 0;
462}
463
464/*
465** The variable-length integer encoding is as follows:
466**
467** KEY:
468** A = 0xxxxxxx 7 bits of data and one flag bit
469** B = 1xxxxxxx 7 bits of data and one flag bit
470** C = xxxxxxxx 8 bits of data
471**
472** 7 bits - A
473** 14 bits - BA
474** 21 bits - BBA
475** 28 bits - BBBA
476** 35 bits - BBBBA
477** 42 bits - BBBBBA
478** 49 bits - BBBBBBA
479** 56 bits - BBBBBBBA
480** 64 bits - BBBBBBBBC
481*/
482
483/*
484** Write a 64-bit variable-length integer to memory starting at p[0].
485** The length of data write will be between 1 and 9 bytes. The number
486** of bytes written is returned.
487**
488** A variable-length integer consists of the lower 7 bits of each byte
489** for all bytes that have the 8th bit set and one byte with the 8th
490** bit clear. Except, if we get to the 9th byte, it stores the full
491** 8 bits and is the last byte.
492*/
493int sqlite3PutVarint(unsigned char *p, u64 v){
494 int i, j, n;
495 u8 buf[10];
496 if( v & (((u64)0xff000000)<<32) ){
497 p[8] = v;
498 v >>= 8;
499 for(i=7; i>=0; i--){
500 p[i] = (v & 0x7f) | 0x80;
501 v >>= 7;
502 }
503 return 9;
504 }
505 n = 0;
506 do{
507 buf[n++] = (v & 0x7f) | 0x80;
508 v >>= 7;
509 }while( v!=0 );
510 buf[0] &= 0x7f;
511 assert( n<=9 );
512 for(i=0, j=n-1; j>=0; j--, i++){
513 p[i] = buf[j];
514 }
515 return n;
516}
517
518/*
519** Read a 64-bit variable-length integer from memory starting at p[0].
520** Return the number of bytes read. The value is stored in *v.
521*/
522int sqlite3GetVarint(const unsigned char *p, u64 *v){
523 u32 x;
524 u64 x64;
525 int n;
526 unsigned char c;
527 if( ((c = p[0]) & 0x80)==0 ){
528 *v = c;
529 return 1;
530 }
531 x = c & 0x7f;
532 if( ((c = p[1]) & 0x80)==0 ){
533 *v = (x<<7) | c;
534 return 2;
535 }
536 x = (x<<7) | (c&0x7f);
537 if( ((c = p[2]) & 0x80)==0 ){
538 *v = (x<<7) | c;
539 return 3;
540 }
541 x = (x<<7) | (c&0x7f);
542 if( ((c = p[3]) & 0x80)==0 ){
543 *v = (x<<7) | c;
544 return 4;
545 }
546 x64 = (x<<7) | (c&0x7f);
547 n = 4;
548 do{
549 c = p[n++];
550 if( n==9 ){
551 x64 = (x64<<8) | c;
552 break;
553 }
554 x64 = (x64<<7) | (c&0x7f);
555 }while( (c & 0x80)!=0 );
556 *v = x64;
557 return n;
558}
559
560/*
561** Read a 32-bit variable-length integer from memory starting at p[0].
562** Return the number of bytes read. The value is stored in *v.
563*/
564int sqlite3GetVarint32(const unsigned char *p, u32 *v){
565 u32 x;
566 int n;
567 unsigned char c;
568 if( ((signed char*)p)[0]>=0 ){
569 *v = p[0];
570 return 1;
571 }
572 x = p[0] & 0x7f;
573 if( ((signed char*)p)[1]>=0 ){
574 *v = (x<<7) | p[1];
575 return 2;
576 }
577 x = (x<<7) | (p[1] & 0x7f);
578 n = 2;
579 do{
580 x = (x<<7) | ((c = p[n++])&0x7f);
581 }while( (c & 0x80)!=0 && n<9 );
582 *v = x;
583 return n;
584}
585
586/*
587** Return the number of bytes that will be needed to store the given
588** 64-bit integer.
589*/
590int sqlite3VarintLen(u64 v){
591 int i = 0;
592 do{
593 i++;
594 v >>= 7;
595 }while( v!=0 && i<9 );
596 return i;
597}
598
599
600/*
601** Read or write a four-byte big-endian integer value.
602*/
603u32 sqlite3Get4byte(const u8 *p){
604 return (p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
605}
606void sqlite3Put4byte(unsigned char *p, u32 v){
607 p[0] = v>>24;
608 p[1] = v>>16;
609 p[2] = v>>8;
610 p[3] = v;
611}
612
613
614
615#if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC) \
616 || defined(SQLITE_TEST)
617/*
618** Translate a single byte of Hex into an integer.
619*/
620static int hexToInt(int h){
621 if( h>='0' && h<='9' ){
622 return h - '0';
623 }else if( h>='a' && h<='f' ){
624 return h - 'a' + 10;
625 }else{
626 assert( h>='A' && h<='F' );
627 return h - 'A' + 10;
628 }
629}
630#endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC || SQLITE_TEST */
631
632#if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC)
633/*
634** Convert a BLOB literal of the form "x'hhhhhh'" into its binary
635** value. Return a pointer to its binary value. Space to hold the
636** binary value has been obtained from malloc and must be freed by
637** the calling routine.
638*/
639void *sqlite3HexToBlob(sqlite3 *db, const char *z){
640 char *zBlob;
641 int i;
642 int n = strlen(z);
643 if( n%2 ) return 0;
644
645 zBlob = (char *)sqlite3DbMallocRaw(db, n/2);
646 if( zBlob ){
647 for(i=0; i<n; i+=2){
648 zBlob[i/2] = (hexToInt(z[i])<<4) | hexToInt(z[i+1]);
649 }
650 }
651 return zBlob;
652}
653#endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC */
654
655
656/*
657** Change the sqlite.magic from SQLITE_MAGIC_OPEN to SQLITE_MAGIC_BUSY.
658** Return an error (non-zero) if the magic was not SQLITE_MAGIC_OPEN
659** when this routine is called.
660**
661** This routine is called when entering an SQLite API. The SQLITE_MAGIC_OPEN
662** value indicates that the database connection passed into the API is
663** open and is not being used by another thread. By changing the value
664** to SQLITE_MAGIC_BUSY we indicate that the connection is in use.
665** sqlite3SafetyOff() below will change the value back to SQLITE_MAGIC_OPEN
666** when the API exits.
667**
668** This routine is a attempt to detect if two threads use the
669** same sqlite* pointer at the same time. There is a race
670** condition so it is possible that the error is not detected.
671** But usually the problem will be seen. The result will be an
672** error which can be used to debug the application that is
673** using SQLite incorrectly.
674**
675** Ticket #202: If db->magic is not a valid open value, take care not
676** to modify the db structure at all. It could be that db is a stale
677** pointer. In other words, it could be that there has been a prior
678** call to sqlite3_close(db) and db has been deallocated. And we do
679** not want to write into deallocated memory.
680*/
681int sqlite3SafetyOn(sqlite3 *db){
682 if( db->magic==SQLITE_MAGIC_OPEN ){
683 db->magic = SQLITE_MAGIC_BUSY;
684 return 0;
685 }else if( db->magic==SQLITE_MAGIC_BUSY ){
686 db->magic = SQLITE_MAGIC_ERROR;
687 db->u1.isInterrupted = 1;
688 }
689 return 1;
690}
691
692/*
693** Change the magic from SQLITE_MAGIC_BUSY to SQLITE_MAGIC_OPEN.
694** Return an error (non-zero) if the magic was not SQLITE_MAGIC_BUSY
695** when this routine is called.
696*/
697int sqlite3SafetyOff(sqlite3 *db){
698 if( db->magic==SQLITE_MAGIC_BUSY ){
699 db->magic = SQLITE_MAGIC_OPEN;
700 return 0;
701 }else {
702 db->magic = SQLITE_MAGIC_ERROR;
703 db->u1.isInterrupted = 1;
704 return 1;
705 }
706}
generated by cgit v1.1 at 2024-12-27 10:56:15 +0000