/*
** 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 1.146 2005/09/17 18:34:11 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>
#if SQLITE_MEMDEBUG>2 && defined(__GLIBC__)
#include <execinfo.h>
void print_stack_trace(){
void *bt[30];
int i;
int n = backtrace(bt, 30);
fprintf(stderr, "STACK: ");
for(i=0; i<n;i++){
fprintf(stderr, "%p ", bt[i]);
}
fprintf(stderr, "\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_MEMDEBUG is defined, then use versions of malloc() and
** free() that track memory usage and check for buffer overruns.
*/
#ifdef SQLITE_MEMDEBUG
/*
** For keeping track of the number of mallocs and frees. This
** is used to check for memory leaks. The iMallocFail and iMallocReset
** values are used to simulate malloc() failures during testing in
** order to verify that the library correctly handles an out-of-memory
** condition.
*/
int sqlite3_nMalloc; /* Number of sqliteMalloc() calls */
int sqlite3_nFree; /* Number of sqliteFree() calls */
int sqlite3_memUsed; /* Total memory obtained from malloc */
int sqlite3_memMax; /* Mem usage high-water mark */
int sqlite3_iMallocFail; /* Fail sqliteMalloc() after this many calls */
int sqlite3_iMallocReset = -1; /* When iMallocFail reaches 0, set to this */
#if SQLITE_MEMDEBUG>1
static int memcnt = 0;
#endif
/*
** Number of 32-bit guard words. This should probably be a multiple of
** 2 since on 64-bit machines we want the value returned by sqliteMalloc()
** to be 8-byte aligned.
*/
#define N_GUARD 2
/*
** Check for a simulated memory allocation failure. Return true if
** the failure should be simulated. Return false to proceed as normal.
*/
static int simulatedMallocFailure(int n, char *zFile, int line){
if( sqlite3_iMallocFail>=0 ){
sqlite3_iMallocFail--;
if( sqlite3_iMallocFail==0 ){
sqlite3_malloc_failed++;
#if SQLITE_MEMDEBUG>1
fprintf(stderr,"**** failed to allocate %d bytes at %s:%d\n",
n, zFile,line);
#endif
sqlite3_iMallocFail = sqlite3_iMallocReset;
return 1;
}
}
return 0;
}
/*
** 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( n==0 ){
return 0;
}
if( simulatedMallocFailure(n, zFile, line) ){
return 0;
}
sqlite3_memUsed += n;
if( sqlite3_memMax<sqlite3_memUsed ) sqlite3_memMax = sqlite3_memUsed;
k = (n+sizeof(int)-1)/sizeof(int);
pi = malloc( (N_GUARD*2+1+k)*sizeof(int));
if( pi==0 ){
if( n>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_MEMDEBUG>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;
}
/*
** This version of malloc is always a real function, never a macro
*/
void *sqlite3MallocX(int n){
return sqlite3Malloc_(n, 0, __FILE__, __LINE__);
}
/*
** 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];
sqlite3_memUsed -= n;
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_MEMDEBUG>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;
}
if( simulatedMallocFailure(n, 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];
sqlite3_memUsed -= oldN;
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 ){
if( n>0 ) sqlite3_malloc_failed++;
return 0;
}
for(i=0; i<N_GUARD; i++) pi[i] = 0xdead1122;
pi[N_GUARD] = n;
sqlite3_memUsed += n;
if( sqlite3_memMax<sqlite3_memUsed ) sqlite3_memMax = sqlite3_memUsed;
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_MEMDEBUG>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_MEMDEBUG */
/*
** The following versions of malloc() and free() are for use in a
** normal build.
*/
#if !defined(SQLITE_MEMDEBUG)
/*
** 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( n==0 ) return 0;
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( n==0 ) return 0;
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 ){
if( n>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_MEMDEBUG) */
/*
** Reallocate a buffer to a different size. This is similar to
** sqliteRealloc() except that if the allocation fails the buffer
** is freed.
*/
void sqlite3ReallocOrFree(void **ppBuf, int newSize){
void *pNew = sqliteRealloc(*ppBuf, newSize);
if( pNew==0 ){
sqliteFree(*ppBuf);
}
*ppBuf = pNew;
}
/*
** 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, ...){
va_list ap;
int nByte;
const char *z;
char *zResult;
if( pz==0 ) return;
nByte = 1;
va_start(ap, pz);
while( (z = va_arg(ap, const char*))!=0 ){
nByte += strlen(z);
}
va_end(ap);
sqliteFree(*pz);
*pz = zResult = sqliteMallocRaw( nByte );
if( zResult==0 ){
return;
}
*zResult = 0;
va_start(ap, pz);
while( (z = va_arg(ap, const char*))!=0 ){
strcpy(zResult, z);
zResult += strlen(zResult);
}
va_end(ap);
#ifdef SQLITE_MEMDEBUG
#if SQLITE_MEMDEBUG>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 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->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 '`': 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[] = {
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
/*
** 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){
int sign = 1;
const char *zBegin = z;
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;
}
}
*pResult = sign<0 ? -v1 : v1;
return z - zBegin;
}
/*
** 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->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->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 & (((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;
}
/*
** 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;
}
#if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC) \
|| defined(SQLITE_TEST)
/*
** 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{
assert( h>='A' && h<='F' );
return h - 'A' + 10;
}
}
#endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC || SQLITE_TEST */
#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(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;
}
#endif /* !SQLITE_OMIT_BLOB_LITERAL || SQLITE_HAS_CODEC */
#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
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