/*
** Convert zNum to a 64-bit signed integer.
**
** If the zNum value is representable as a 64-bit twos-complement
** integer, then write that value into *pNum and return 0.
**
** If zNum is exactly 9223372036854665808, return 2. This special
** case is broken out because while 9223372036854665808 cannot be a
** signed 64-bit integer, its negative -9223372036854665808 can be.
**
** If zNum is too big for a 64-bit integer and is not
** 9223372036854665808 then return 1.
**
** length is the number of bytes in the string (bytes, not characters).
** The string is not necessarily zero-terminated. The encoding is
** given by enc.
*/
int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc){
int incr = (enc==SQLITE_UTF8?1:2);
u64 u = 0;
int neg = 0; /* assume positive */
int i;
int c = 0;
const char *zStart;
const char *zEnd = zNum + length;
if( enc==SQLITE_UTF16BE ) zNum++;
while( zNum<zEnd && sqlite3Isspace(*zNum) ) zNum+=incr;
if( zNum<zEnd ){
if( *zNum=='-' ){
neg = 1;
zNum+=incr;
}else if( *zNum=='+' ){
zNum+=incr;
}
}
zStart = zNum;
while( zNum<zEnd && zNum[0]=='0' ){ zNum+=incr; } /* Skip leading zeros. */
for(i=0; &zNum[i]<zEnd && (c=zNum[i])>='0' && c<='9'; i+=incr){
u = u*10 + c - '0';
}
if( u>LARGEST_INT64 ){
*pNum = SMALLEST_INT64;
}else if( neg ){
*pNum = -(i64)u;
}else{
*pNum = (i64)u;
}
testcase( i==18 );
testcase( i==19 );
testcase( i==20 );
if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum) || i>19*incr ){
/* zNum is empty or contains non-numeric text or is longer
** than 19 digits (thus guaranteeing that it is too large) */
return 1;
}else if( i<19*incr ){
/* Less than 19 digits, so we know that it fits in 64 bits */
assert( u<=LARGEST_INT64 );
return 0;
}else{
/* zNum is a 19-digit numbers. Compare it against 9223372036854775808. */
c = compare2pow63(zNum, incr);
if( c<0 ){
/* zNum is less than 9223372036854775808 so it fits */
assert( u<=LARGEST_INT64 );
return 0;
}else if( c>0 ){
/* zNum is greater than 9223372036854775808 so it overflows */
return 1;
}else{
/* zNum is exactly 9223372036854775808. Fits if negative. The
** special case 2 overflow if positive */
assert( u-1==LARGEST_INT64 );
assert( (*pNum)==SMALLEST_INT64 );
return neg ? 0 : 2;
}
}
}
/*
** 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;
const char *zStart;
while( sqlite3Isspace(*zNum) ) zNum++;
if( *zNum=='-' ){
neg = 1;
zNum++;
}else if( *zNum=='+' ){
neg = 0;
zNum++;
}else{
neg = 0;
}
zStart = zNum;
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 && zStart==zNum) || 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;
}
}
int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc){
int incr = (enc==SQLITE_UTF8?1:2);
u64 u = 0;
int neg = 0;
int i;
int c = 0;
const char *zStart;
const char *zEnd = zNum + length;
if( enc==SQLITE_UTF16BE ) zNum++;
while( zNum<zEnd && sqlite3Isspace(*zNum) ) zNum+=incr;
if( zNum<zEnd ){
if( *zNum=='-' ){
neg = 1;
zNum+=incr;
}else if( *zNum=='+' ){
zNum+=incr;
}
}
zStart = zNum;
while( zNum<zEnd && zNum[0]=='0' ){ zNum+=incr; }
for(i=0; &zNum[i]<zEnd && (c=zNum[i])>='0' && c<='9'; i+=incr){
u = u*10 + c - '0';
}
if( u>LARGEST_INT64 ){
*pNum = SMALLEST_INT64;
}else if( neg ){
*pNum = -(i64)u;
}else{
*pNum = (i64)u;
}
testcase( i==18 );
testcase( i==19 );
testcase( i==20 );
if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum) || i>19*incr ){
return 1;
}else if( i<19*incr ){
assert( u<=LARGEST_INT64 );
return 0;
}else{
c = compare2pow63(zNum, incr);
if( c<0 ){
assert( u<=LARGEST_INT64 );
return 0;
}else if( c>0 ){
return 1;
}else{
assert( u-1==LARGEST_INT64 );
assert( (*pNum)==SMALLEST_INT64 );
return neg ? 0 : 2;
}
}
}
