util.c
上传用户:sunhongbo
上传日期:2022-01-25
资源大小:3010k
文件大小:21k
- /*
- ** 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: util.c,v 1.222 2008/04/16 00:49:12 drh Exp $
- */
- #include "sqliteInt.h"
- #include <stdarg.h>
- #include <ctype.h>
- /*
- ** 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 sqlite 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))!=0) ){
- db->errCode = err_code;
- if( zFormat ){
- char *z;
- va_list ap;
- va_start(ap, zFormat);
- z = sqlite3VMPrintf(db, zFormat, ap);
- va_end(ap);
- sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, sqlite3_free);
- }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++;
- sqlite3_free(pParse->zErrMsg);
- va_start(ap, zFormat);
- pParse->zErrMsg = sqlite3VMPrintf(pParse->db, zFormat, ap);
- va_end(ap);
- if( pParse->rc==SQLITE_OK ){
- pParse->rc = SQLITE_ERROR;
- }
- }
- /*
- ** Clear the error message in pParse, if any
- */
- void sqlite3ErrorClear(Parse *pParse){
- sqlite3_free(pParse->zErrMsg);
- pParse->zErrMsg = 0;
- pParse->nErr = 0;
- }
- /*
- ** 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 '`': break; /* For MySQL compatibility */
- case '[': quote = ']'; break; /* For MS SqlServer compatibility */
- 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[] = {
- #ifdef SQLITE_ASCII
- 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
- #endif
- #ifdef SQLITE_EBCDIC
- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, /* 0x */
- 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, /* 1x */
- 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, /* 2x */
- 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, /* 3x */
- 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, /* 4x */
- 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, /* 5x */
- 96, 97, 66, 67, 68, 69, 70, 71, 72, 73,106,107,108,109,110,111, /* 6x */
- 112, 81, 82, 83, 84, 85, 86, 87, 88, 89,122,123,124,125,126,127, /* 7x */
- 128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143, /* 8x */
- 144,145,146,147,148,149,150,151,152,153,154,155,156,157,156,159, /* 9x */
- 160,161,162,163,164,165,166,167,168,169,170,171,140,141,142,175, /* Ax */
- 176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191, /* Bx */
- 192,129,130,131,132,133,134,135,136,137,202,203,204,205,206,207, /* Cx */
- 208,145,146,147,148,149,150,151,152,153,218,219,220,221,222,223, /* Dx */
- 224,225,162,163,164,165,166,167,168,169,232,203,204,205,206,207, /* Ex */
- 239,240,241,242,243,244,245,246,247,248,249,219,220,221,222,255, /* Fx */
- #endif
- };
- #define UpperToLower sqlite3UpperToLower
- /*
- ** 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.
- */
- int sqlite3AtoF(const char *z, double *pResult){
- #ifndef SQLITE_OMIT_FLOATING_POINT
- int sign = 1;
- const char *zBegin = z;
- LONGDOUBLE_TYPE v1 = 0.0;
- while( isspace(*(u8*)z) ) z++;
- 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;
- }
- }
- *pResult = sign<0 ? -v1 : v1;
- return z - zBegin;
- #else
- return sqlite3Atoi64(z, pResult);
- #endif /* SQLITE_OMIT_FLOATING_POINT */
- }
- /*
- ** Compare the 19-character string zNum against the text representation
- ** value 2^63: 9223372036854775808. Return negative, zero, or positive
- ** if zNum is less than, equal to, or greater than the string.
- **
- ** Unlike memcmp() this routine is guaranteed to return the difference
- ** in the values of the last digit if the only difference is in the
- ** last digit. So, for example,
- **
- ** compare2pow63("9223372036854775800")
- **
- ** will return -8.
- */
- static int compare2pow63(const char *zNum){
- int c;
- c = memcmp(zNum,"922337203685477580",18);
- if( c==0 ){
- c = zNum[18] - '8';
- }
- return c;
- }
- /*
- ** 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.
- **
- ** 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;
- while( isspace(*(u8*)zNum) ) zNum++;
- if( *zNum=='-' ){
- neg = 1;
- zNum++;
- }else if( *zNum=='+' ){
- neg = 0;
- zNum++;
- }else{
- neg = 0;
- }
- while( zNum[0]=='0' ){ zNum++; } /* Skip over leading zeros. Ticket #2454 */
- for(i=0; (c=zNum[i])>='0' && c<='9'; i++){
- v = v*10 + c - '0';
- }
- *pNum = neg ? -v : v;
- if( c!=0 || i==0 || i>19 ){
- /* zNum is empty or contains non-numeric text or is longer
- ** than 19 digits (thus guaranting that it is too large) */
- return 0;
- }else if( i<19 ){
- /* Less than 19 digits, so we know that it fits in 64 bits */
- return 1;
- }else{
- /* 19-digit numbers must be no larger than 9223372036854775807 if positive
- ** or 9223372036854775808 if negative. Note that 9223372036854665808
- ** is 2^63. */
- return compare2pow63(zNum)<neg;
- }
- }
- /*
- ** 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 negFlag){
- int i, c;
- int neg = 0;
- if( *zNum=='-' ){
- neg = 1;
- zNum++;
- }else if( *zNum=='+' ){
- zNum++;
- }
- if( negFlag ) neg = 1-neg;
- while( *zNum=='0' ){
- zNum++; /* Skip leading zeros. Ticket #2454 */
- }
- for(i=0; (c=zNum[i])>='0' && c<='9'; i++){}
- if( i<19 ){
- /* Guaranteed to fit if less than 19 digits */
- return 1;
- }else if( i>19 ){
- /* Guaranteed to be too big if greater than 19 digits */
- return 0;
- }else{
- /* Compare against 2^63. */
- return compare2pow63(zNum)<neg;
- }
- }
- /*
- ** If zNum represents an integer that will fit in 32-bits, then set
- ** *pValue to that integer and return true. Otherwise return false.
- **
- ** Any non-numeric characters that following zNum are ignored.
- ** This is different from sqlite3Atoi64() which requires the
- ** input number to be zero-terminated.
- */
- int sqlite3GetInt32(const char *zNum, int *pValue){
- sqlite_int64 v = 0;
- int i, c;
- int neg = 0;
- if( zNum[0]=='-' ){
- neg = 1;
- zNum++;
- }else if( zNum[0]=='+' ){
- zNum++;
- }
- while( zNum[0]=='0' ) zNum++;
- for(i=0; i<11 && (c = zNum[i] - '0')>=0 && c<=9; i++){
- v = v*10 + c;
- }
- /* The longest decimal representation of a 32 bit integer is 10 digits:
- **
- ** 1234567890
- ** 2^31 -> 2147483648
- */
- if( i>10 ){
- return 0;
- }
- if( v-neg>2147483647 ){
- return 0;
- }
- if( neg ){
- v = -v;
- }
- *pValue = (int)v;
- return 1;
- }
- /*
- ** 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 & (((u64)0xff000000)<<32) ){
- 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;
- }
- /*
- ** This routine is a faster version of sqlite3PutVarint() that only
- ** works for 32-bit positive integers and which is optimized for
- ** the common case of small integers.
- */
- int sqlite3PutVarint32(unsigned char *p, u32 v){
- if( (v & ~0x7f)==0 ){
- p[0] = v;
- return 1;
- }else if( (v & ~0x3fff)==0 ){
- p[0] = (v>>7) | 0x80;
- p[1] = v & 0x7f;
- return 2;
- }else{
- return sqlite3PutVarint(p, v);
- }
- }
- /*
- ** 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( ((signed char*)p)[0]>=0 ){
- *v = p[0];
- return 1;
- }
- x = p[0] & 0x7f;
- if( ((signed char*)p)[1]>=0 ){
- *v = (x<<7) | p[1];
- return 2;
- }
- x = (x<<7) | (p[1] & 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;
- }
- /*
- ** Read or write a four-byte big-endian integer value.
- */
- u32 sqlite3Get4byte(const u8 *p){
- return (p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
- }
- void sqlite3Put4byte(unsigned char *p, u32 v){
- p[0] = v>>24;
- p[1] = v>>16;
- p[2] = v>>8;
- p[3] = v;
- }
- #if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC)
- /*
- ** Translate a single byte of Hex into an integer.
- ** This routinen only works if h really is a valid hexadecimal
- ** character: 0..9a..fA..F
- */
- static int hexToInt(int h){
- assert( (h>='0' && h<='9') || (h>='a' && h<='f') || (h>='A' && h<='F') );
- #ifdef SQLITE_ASCII
- h += 9*(1&(h>>6));
- #endif
- #ifdef SQLITE_EBCDIC
- h += 9*(1&~(h>>4));
- #endif
- return h & 0xf;
- }
- #endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC */
- #if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC)
- /*
- ** 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(sqlite3 *db, const char *z, int n){
- char *zBlob;
- int i;
- zBlob = (char *)sqlite3DbMallocRaw(db, n/2 + 1);
- n--;
- if( zBlob ){
- for(i=0; i<n; i+=2){
- zBlob[i/2] = (hexToInt(z[i])<<4) | hexToInt(z[i+1]);
- }
- zBlob[i/2] = 0;
- }
- return zBlob;
- }
- #endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC */
- /*
- ** 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 called when entering an SQLite API. The SQLITE_MAGIC_OPEN
- ** value indicates that the database connection passed into the API is
- ** open and is not being used by another thread. By changing the value
- ** to SQLITE_MAGIC_BUSY we indicate that the connection is in use.
- ** sqlite3SafetyOff() below will change the value back to SQLITE_MAGIC_OPEN
- ** when the API exits.
- **
- ** 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.
- */
- #ifdef SQLITE_DEBUG
- int sqlite3SafetyOn(sqlite3 *db){
- if( db->magic==SQLITE_MAGIC_OPEN ){
- db->magic = SQLITE_MAGIC_BUSY;
- assert( sqlite3_mutex_held(db->mutex) );
- return 0;
- }else if( db->magic==SQLITE_MAGIC_BUSY ){
- db->magic = SQLITE_MAGIC_ERROR;
- db->u1.isInterrupted = 1;
- }
- return 1;
- }
- #endif
- /*
- ** 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.
- */
- #ifdef SQLITE_DEBUG
- int sqlite3SafetyOff(sqlite3 *db){
- if( db->magic==SQLITE_MAGIC_BUSY ){
- db->magic = SQLITE_MAGIC_OPEN;
- assert( sqlite3_mutex_held(db->mutex) );
- return 0;
- }else{
- db->magic = SQLITE_MAGIC_ERROR;
- db->u1.isInterrupted = 1;
- return 1;
- }
- }
- #endif
- /*
- ** 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
- ** 1 it means that the db pointer is valid and 0 if it should not be
- ** dereferenced for any reason. The calling function should invoke
- ** SQLITE_MISUSE immediately.
- **
- ** sqlite3SafetyCheckOk() requires that the db pointer be valid for
- ** use. sqlite3SafetyCheckSickOrOk() allows a db pointer that failed to
- ** open properly and is not fit for general use but which can be
- ** used as an argument to sqlite3_errmsg() or sqlite3_close().
- */
- int sqlite3SafetyCheckOk(sqlite3 *db){
- int magic;
- if( db==0 ) return 0;
- magic = db->magic;
- if( magic!=SQLITE_MAGIC_OPEN &&
- magic!=SQLITE_MAGIC_BUSY ) return 0;
- return 1;
- }
- int sqlite3SafetyCheckSickOrOk(sqlite3 *db){
- int magic;
- if( db==0 ) return 0;
- magic = db->magic;
- if( magic!=SQLITE_MAGIC_SICK &&
- magic!=SQLITE_MAGIC_OPEN &&
- magic!=SQLITE_MAGIC_BUSY ) return 0;
- return 1;
- }