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sqlite/src/util.c
shaneh 1da207e676 Minor changes to silence compiler warnings on various MSVC builds. 
FossilOrigin-Name: 115c978b6bbc110119a1b2f178cc30b33aaa27ef
2010-03-09 14:41:12 +00:00

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/*
** 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.
**
*/
#include "sqliteInt.h"
#include <stdarg.h>
#ifdef SQLITE_HAVE_ISNAN
# include <math.h>
#endif
/*
** Routine needed to support the testcase() macro.
*/
#ifdef SQLITE_COVERAGE_TEST
void sqlite3Coverage(int x){
static int dummy = 0;
dummy += x;
}
#endif
#ifndef SQLITE_OMIT_FLOATING_POINT
/*
** Return true if the floating point value is Not a Number (NaN).
**
** Use the math library isnan() function if compiled with SQLITE_HAVE_ISNAN.
** Otherwise, we have our own implementation that works on most systems.
*/
int sqlite3IsNaN(double x){
int rc; /* The value return */
#if !defined(SQLITE_HAVE_ISNAN)
/*
** Systems that support the isnan() library function should probably
** make use of it by compiling with -DSQLITE_HAVE_ISNAN. But we have
** found that many systems do not have a working isnan() function so
** this implementation is provided as an alternative.
**
** This NaN test sometimes fails if compiled on GCC with -ffast-math.
** On the other hand, the use of -ffast-math comes with the following
** warning:
**
** This option [-ffast-math] should never be turned on by any
** -O option since it can result in incorrect output for programs
** which depend on an exact implementation of IEEE or ISO
** rules/specifications for math functions.
**
** Under MSVC, this NaN test may fail if compiled with a floating-
** point precision mode other than /fp:precise. From the MSDN
** documentation:
**
** The compiler [with /fp:precise] will properly handle comparisons
** involving NaN. For example, x != x evaluates to true if x is NaN
** ...
*/
#ifdef __FAST_MATH__
# error SQLite will not work correctly with the -ffast-math option of GCC.
#endif
volatile double y = x;
volatile double z = y;
rc = (y!=z);
#else /* if defined(SQLITE_HAVE_ISNAN) */
rc = isnan(x);
#endif /* SQLITE_HAVE_ISNAN */
testcase( rc );
return rc;
}
#endif /* SQLITE_OMIT_FLOATING_POINT */
/*
** Compute a string length that is limited to what can be stored in
** lower 30 bits of a 32-bit signed integer.
**
** The value returned will never be negative. Nor will it ever be greater
** than the actual length of the string. For very long strings (greater
** than 1GiB) the value returned might be less than the true string length.
*/
int sqlite3Strlen30(const char *z){
const char *z2 = z;
if( z==0 ) return 0;
while( *z2 ){ z2++; }
return 0x3fffffff & (int)(z2 - z);
}
/*
** 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, SQLITE_DYNAMIC);
}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, ...){
char *zMsg;
va_list ap;
sqlite3 *db = pParse->db;
va_start(ap, zFormat);
zMsg = sqlite3VMPrintf(db, zFormat, ap);
va_end(ap);
if( db->suppressErr ){
sqlite3DbFree(db, zMsg);
}else{
pParse->nErr++;
sqlite3DbFree(db, pParse->zErrMsg);
pParse->zErrMsg = zMsg;
pParse->rc = SQLITE_ERROR;
}
}
/*
** 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.
**
** The input string must be zero-terminated. A new zero-terminator
** is added to the dequoted string.
**
** The return value is -1 if no dequoting occurs or the length of the
** dequoted string, exclusive of the zero terminator, if dequoting does
** occur.
**
** 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".
*/
int sqlite3Dequote(char *z){
char quote;
int i, j;
if( z==0 ) return -1;
quote = z[0];
switch( quote ){
case '\'': break;
case '"': break;
case '`': break; /* For MySQL compatibility */
case '[': quote = ']'; break; /* For MS SqlServer compatibility */
default: return -1;
}
for(i=1, j=0; ALWAYS(z[i]); i++){
if( z[i]==quote ){
if( z[i+1]==quote ){
z[j++] = quote;
i++;
}else{
break;
}
}else{
z[j++] = z[i];
}
}
z[j] = 0;
return j;
}
/* Convenient short-hand */
#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 sqlite3_strnicmp(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 and leave
** *realnum unchanged if the string contains any character which is not
** part of a number.
**
** If the string is pure numeric, set *realnum to TRUE if the string
** contains the '.' character or an "E+000" style exponentiation suffix.
** Otherwise set *realnum to FALSE. Note that just becaue *realnum is
** false does not mean that the number can be successfully converted into
** an integer - it might be too big.
**
** 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( !sqlite3Isdigit(*z) ){
return 0;
}
z += incr;
*realnum = 0;
while( sqlite3Isdigit(*z) ){ z += incr; }
#ifndef SQLITE_OMIT_FLOATING_POINT
if( *z=='.' ){
z += incr;
if( !sqlite3Isdigit(*z) ) return 0;
while( sqlite3Isdigit(*z) ){ z += incr; }
*realnum = 1;
}
if( *z=='e' || *z=='E' ){
z += incr;
if( *z=='+' || *z=='-' ) z += incr;
if( !sqlite3Isdigit(*z) ) return 0;
while( sqlite3Isdigit(*z) ){ z += incr; }
*realnum = 1;
}
#endif
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
const char *zBegin = z;
/* sign * significand * (10 ^ (esign * exponent)) */
int sign = 1; /* sign of significand */
i64 s = 0; /* significand */
int d = 0; /* adjust exponent for shifting decimal point */
int esign = 1; /* sign of exponent */
int e = 0; /* exponent */
double result;
int nDigits = 0;
/* skip leading spaces */
while( sqlite3Isspace(*z) ) z++;
/* get sign of significand */
if( *z=='-' ){
sign = -1;
z++;
}else if( *z=='+' ){
z++;
}
/* skip leading zeroes */
while( z[0]=='0' ) z++, nDigits++;
/* copy max significant digits to significand */
while( sqlite3Isdigit(*z) && s<((LARGEST_INT64-9)/10) ){
s = s*10 + (*z - '0');
z++, nDigits++;
}
/* skip non-significant significand digits
** (increase exponent by d to shift decimal left) */
while( sqlite3Isdigit(*z) ) z++, nDigits++, d++;
/* if decimal point is present */
if( *z=='.' ){
z++;
/* copy digits from after decimal to significand
** (decrease exponent by d to shift decimal right) */
while( sqlite3Isdigit(*z) && s<((LARGEST_INT64-9)/10) ){
s = s*10 + (*z - '0');
z++, nDigits++, d--;
}
/* skip non-significant digits */
while( sqlite3Isdigit(*z) ) z++, nDigits++;
}
/* if exponent is present */
if( *z=='e' || *z=='E' ){
z++;
/* get sign of exponent */
if( *z=='-' ){
esign = -1;
z++;
}else if( *z=='+' ){
z++;
}
/* copy digits to exponent */
while( sqlite3Isdigit(*z) ){
e = e*10 + (*z - '0');
z++;
}
}
/* adjust exponent by d, and update sign */
e = (e*esign) + d;
if( e<0 ) {
esign = -1;
e *= -1;
} else {
esign = 1;
}
/* if 0 significand */
if( !s ) {
/* In the IEEE 754 standard, zero is signed.
** Add the sign if we've seen at least one digit */
result = (sign<0 && nDigits) ? -(double)0 : (double)0;
} else {
/* attempt to reduce exponent */
if( esign>0 ){
while( s<(LARGEST_INT64/10) && e>0 ) e--,s*=10;
}else{
while( !(s%10) && e>0 ) e--,s/=10;
}
/* adjust the sign of significand */
s = sign<0 ? -s : s;
/* if exponent, scale significand as appropriate
** and store in result. */
if( e ){
double scale = 1.0;
/* attempt to handle extremely small/large numbers better */
if( e>307 && e<342 ){
while( e%308 ) { scale *= 1.0e+1; e -= 1; }
if( esign<0 ){
result = s / scale;
result /= 1.0e+308;
}else{
result = s * scale;
result *= 1.0e+308;
}
}else{
/* 1.0e+22 is the largest power of 10 than can be
** represented exactly. */
while( e%22 ) { scale *= 1.0e+1; e -= 1; }
while( e>0 ) { scale *= 1.0e+22; e -= 22; }
if( esign<0 ){
result = s / scale;
}else{
result = s * scale;
}
}
} else {
result = (double)s;
}
}
/* store the result */
*pResult = result;
/* return number of characters used */
return (int)(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)*10;
if( c==0 ){
c = zNum[18] - '8';
testcase( c==(-1) );
testcase( c==0 );
testcase( c==(+1) );
}
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;
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;
testcase( i==18 );
testcase( i==19 );
testcase( i==20 );
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 unsigned integer. The zNum string
** consists of one or more digit characters and is terminated by
** a zero character. Any stray characters in zNum result in undefined
** behavior.
**
** If the unsigned integer that zNum represents will fit in a
** 64-bit signed integer, return TRUE. Otherwise return FALSE.
**
** If the negFlag parameter is true, that means that zNum really represents
** a negative number. (The leading "-" is omitted from zNum.) This
** parameter is needed to determine a boundary case. A string
** of "9223373036854775808" returns false if negFlag is false or true
** if negFlag is true.
**
** Leading zeros are ignored.
*/
int sqlite3FitsIn64Bits(const char *zNum, int negFlag){
int i;
int neg = 0;
assert( zNum[0]>='0' && zNum[0]<='9' ); /* zNum is an unsigned number */
if( negFlag ) neg = 1-neg;
while( *zNum=='0' ){
zNum++; /* Skip leading zeros. Ticket #2454 */
}
for(i=0; zNum[i]; i++){ assert( zNum[i]>='0' && zNum[i]<='9' ); }
testcase( i==18 );
testcase( i==19 );
testcase( i==20 );
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
*/
testcase( i==10 );
if( i>10 ){
return 0;
}
testcase( v-neg==2147483647 );
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] = (u8)v;
v >>= 8;
for(i=7; i>=0; i--){
p[i] = (u8)((v & 0x7f) | 0x80);
v >>= 7;
}
return 9;
}
n = 0;
do{
buf[n++] = (u8)((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. A MACRO version, putVarint32,
** is provided which inlines the single-byte case. All code should use
** the MACRO version as this function assumes the single-byte case has
** already been handled.
*/
int sqlite3PutVarint32(unsigned char *p, u32 v){
#ifndef putVarint32
if( (v & ~0x7f)==0 ){
p[0] = v;
return 1;
}
#endif
if( (v & ~0x3fff)==0 ){
p[0] = (u8)((v>>7) | 0x80);
p[1] = (u8)(v & 0x7f);
return 2;
}
return sqlite3PutVarint(p, v);
}
/*
** Bitmasks used by sqlite3GetVarint(). These precomputed constants
** are defined here rather than simply putting the constant expressions
** inline in order to work around bugs in the RVT compiler.
**
** SLOT_2_0 A mask for (0x7f<<14) | 0x7f
**
** SLOT_4_2_0 A mask for (0x7f<<28) | SLOT_2_0
*/
#define SLOT_2_0 0x001fc07f
#define SLOT_4_2_0 0xf01fc07f
/*
** 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.
*/
u8 sqlite3GetVarint(const unsigned char *p, u64 *v){
u32 a,b,s;
a = *p;
/* a: p0 (unmasked) */
if (!(a&0x80))
{
*v = a;
return 1;
}
p++;
b = *p;
/* b: p1 (unmasked) */
if (!(b&0x80))
{
a &= 0x7f;
a = a<<7;
a |= b;
*v = a;
return 2;
}
/* Verify that constants are precomputed correctly */
assert( SLOT_2_0 == ((0x7f<<14) | (0x7f)) );
assert( SLOT_4_2_0 == ((0xfU<<28) | (0x7f<<14) | (0x7f)) );
p++;
a = a<<14;
a |= *p;
/* a: p0<<14 | p2 (unmasked) */
if (!(a&0x80))
{
a &= SLOT_2_0;
b &= 0x7f;
b = b<<7;
a |= b;
*v = a;
return 3;
}
/* CSE1 from below */
a &= SLOT_2_0;
p++;
b = b<<14;
b |= *p;
/* b: p1<<14 | p3 (unmasked) */
if (!(b&0x80))
{
b &= SLOT_2_0;
/* moved CSE1 up */
/* a &= (0x7f<<14)|(0x7f); */
a = a<<7;
a |= b;
*v = a;
return 4;
}
/* a: p0<<14 | p2 (masked) */
/* b: p1<<14 | p3 (unmasked) */
/* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
/* moved CSE1 up */
/* a &= (0x7f<<14)|(0x7f); */
b &= SLOT_2_0;
s = a;
/* s: p0<<14 | p2 (masked) */
p++;
a = a<<14;
a |= *p;
/* a: p0<<28 | p2<<14 | p4 (unmasked) */
if (!(a&0x80))
{
/* we can skip these cause they were (effectively) done above in calc'ing s */
/* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
/* b &= (0x7f<<14)|(0x7f); */
b = b<<7;
a |= b;
s = s>>18;
*v = ((u64)s)<<32 | a;
return 5;
}
/* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
s = s<<7;
s |= b;
/* s: p0<<21 | p1<<14 | p2<<7 | p3 (masked) */
p++;
b = b<<14;
b |= *p;
/* b: p1<<28 | p3<<14 | p5 (unmasked) */
if (!(b&0x80))
{
/* we can skip this cause it was (effectively) done above in calc'ing s */
/* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */
a &= SLOT_2_0;
a = a<<7;
a |= b;
s = s>>18;
*v = ((u64)s)<<32 | a;
return 6;
}
p++;
a = a<<14;
a |= *p;
/* a: p2<<28 | p4<<14 | p6 (unmasked) */
if (!(a&0x80))
{
a &= SLOT_4_2_0;
b &= SLOT_2_0;
b = b<<7;
a |= b;
s = s>>11;
*v = ((u64)s)<<32 | a;
return 7;
}
/* CSE2 from below */
a &= SLOT_2_0;
p++;
b = b<<14;
b |= *p;
/* b: p3<<28 | p5<<14 | p7 (unmasked) */
if (!(b&0x80))
{
b &= SLOT_4_2_0;
/* moved CSE2 up */
/* a &= (0x7f<<14)|(0x7f); */
a = a<<7;
a |= b;
s = s>>4;
*v = ((u64)s)<<32 | a;
return 8;
}
p++;
a = a<<15;
a |= *p;
/* a: p4<<29 | p6<<15 | p8 (unmasked) */
/* moved CSE2 up */
/* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */
b &= SLOT_2_0;
b = b<<8;
a |= b;
s = s<<4;
b = p[-4];
b &= 0x7f;
b = b>>3;
s |= b;
*v = ((u64)s)<<32 | a;
return 9;
}
/*
** 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.
**
** If the varint stored in p[0] is larger than can fit in a 32-bit unsigned
** integer, then set *v to 0xffffffff.
**
** A MACRO version, getVarint32, is provided which inlines the
** single-byte case. All code should use the MACRO version as
** this function assumes the single-byte case has already been handled.
*/
u8 sqlite3GetVarint32(const unsigned char *p, u32 *v){
u32 a,b;
/* The 1-byte case. Overwhelmingly the most common. Handled inline
** by the getVarin32() macro */
a = *p;
/* a: p0 (unmasked) */
#ifndef getVarint32
if (!(a&0x80))
{
/* Values between 0 and 127 */
*v = a;
return 1;
}
#endif
/* The 2-byte case */
p++;
b = *p;
/* b: p1 (unmasked) */
if (!(b&0x80))
{
/* Values between 128 and 16383 */
a &= 0x7f;
a = a<<7;
*v = a | b;
return 2;
}
/* The 3-byte case */
p++;
a = a<<14;
a |= *p;
/* a: p0<<14 | p2 (unmasked) */
if (!(a&0x80))
{
/* Values between 16384 and 2097151 */
a &= (0x7f<<14)|(0x7f);
b &= 0x7f;
b = b<<7;
*v = a | b;
return 3;
}
/* A 32-bit varint is used to store size information in btrees.
** Objects are rarely larger than 2MiB limit of a 3-byte varint.
** A 3-byte varint is sufficient, for example, to record the size
** of a 1048569-byte BLOB or string.
**
** We only unroll the first 1-, 2-, and 3- byte cases. The very
** rare larger cases can be handled by the slower 64-bit varint
** routine.
*/
#if 1
{
u64 v64;
u8 n;
p -= 2;
n = sqlite3GetVarint(p, &v64);
assert( n>3 && n<=9 );
if( (v64 & SQLITE_MAX_U32)!=v64 ){
*v = 0xffffffff;
}else{
*v = (u32)v64;
}
return n;
}
#else
/* For following code (kept for historical record only) shows an
** unrolling for the 3- and 4-byte varint cases. This code is
** slightly faster, but it is also larger and much harder to test.
*/
p++;
b = b<<14;
b |= *p;
/* b: p1<<14 | p3 (unmasked) */
if (!(b&0x80))
{
/* Values between 2097152 and 268435455 */
b &= (0x7f<<14)|(0x7f);
a &= (0x7f<<14)|(0x7f);
a = a<<7;
*v = a | b;
return 4;
}
p++;
a = a<<14;
a |= *p;
/* a: p0<<28 | p2<<14 | p4 (unmasked) */
if (!(a&0x80))
{
/* Values between 268435456 and 34359738367 */
a &= SLOT_4_2_0;
b &= SLOT_4_2_0;
b = b<<7;
*v = a | b;
return 5;
}
/* We can only reach this point when reading a corrupt database
** file. In that case we are not in any hurry. Use the (relatively
** slow) general-purpose sqlite3GetVarint() routine to extract the
** value. */
{
u64 v64;
u8 n;
p -= 4;
n = sqlite3GetVarint(p, &v64);
assert( n>5 && n<=9 );
*v = (u32)v64;
return n;
}
#endif
}
/*
** 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 && ALWAYS(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] = (u8)(v>>24);
p[1] = (u8)(v>>16);
p[2] = (u8)(v>>8);
p[3] = (u8)v;
}
#if !defined(SQLITE_OMIT_BLOB_LITERAL) || defined(SQLITE_HAS_CODEC)
/*
** Translate a single byte of Hex into an integer.
** This routine only works if h really is a valid hexadecimal
** character: 0..9a..fA..F
*/
static u8 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 (u8)(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 */
/*
** Log an error that is an API call on a connection pointer that should
** not have been used. The "type" of connection pointer is given as the
** argument. The zType is a word like "NULL" or "closed" or "invalid".
*/
static void logBadConnection(const char *zType){
sqlite3_log(SQLITE_MISUSE,
"API call with %s database connection pointer",
zType
);
}
/*
** 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){
u32 magic;
if( db==0 ){
logBadConnection("NULL");
return 0;
}
magic = db->magic;
if( magic!=SQLITE_MAGIC_OPEN ){
if( sqlite3SafetyCheckSickOrOk(db) ){
testcase( sqlite3GlobalConfig.xLog!=0 );
logBadConnection("unopened");
}
return 0;
}else{
return 1;
}
}
int sqlite3SafetyCheckSickOrOk(sqlite3 *db){
u32 magic;
magic = db->magic;
if( magic!=SQLITE_MAGIC_SICK &&
magic!=SQLITE_MAGIC_OPEN &&
magic!=SQLITE_MAGIC_BUSY ){
testcase( sqlite3GlobalConfig.xLog!=0 );
logBadConnection("invalid");
return 0;
}else{
return 1;
}
}
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