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DEFINITIONS
This source file includes following definitions.
- sqlite3ReadUtf8
- sqlite3VdbeMemTranslate
- sqlite3VdbeMemHandleBom
- sqlite3utf8CharLen
- sqlite3utf16to8
- sqlite3utf16ByteLen
- sqlite3utf16Substr
- sqlite3utfSelfTest
/*
** 2004 April 13
**
** 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.
**
*************************************************************************
** This file contains routines used to translate between UTF-8,
** UTF-16, UTF-16BE, and UTF-16LE.
**
** $Id$
**
** Notes on UTF-8:
**
** Byte-0 Byte-1 Byte-2 Byte-3 Value
** 0xxxxxxx 00000000 00000000 0xxxxxxx
** 110yyyyy 10xxxxxx 00000000 00000yyy yyxxxxxx
** 1110zzzz 10yyyyyy 10xxxxxx 00000000 zzzzyyyy yyxxxxxx
** 11110uuu 10uuzzzz 10yyyyyy 10xxxxxx 000uuuuu zzzzyyyy yyxxxxxx
**
**
** Notes on UTF-16: (with wwww+1==uuuuu)
**
** Word-0 Word-1 Value
** 110110ww wwzzzzyy 110111yy yyxxxxxx 000uuuuu zzzzyyyy yyxxxxxx
** zzzzyyyy yyxxxxxx 00000000 zzzzyyyy yyxxxxxx
**
**
** BOM or Byte Order Mark:
** 0xff 0xfe little-endian utf-16 follows
** 0xfe 0xff big-endian utf-16 follows
**
**
** Handling of malformed strings:
**
** SQLite accepts and processes malformed strings without an error wherever
** possible. However this is not possible when converting between UTF-8 and
** UTF-16.
**
** When converting malformed UTF-8 strings to UTF-16, one instance of the
** replacement character U+FFFD for each byte that cannot be interpeted as
** part of a valid unicode character.
**
** When converting malformed UTF-16 strings to UTF-8, one instance of the
** replacement character U+FFFD for each pair of bytes that cannot be
** interpeted as part of a valid unicode character.
**
** This file contains the following public routines:
**
** sqlite3VdbeMemTranslate() - Translate the encoding used by a Mem* string.
** sqlite3VdbeMemHandleBom() - Handle byte-order-marks in UTF16 Mem* strings.
** sqlite3utf16ByteLen() - Calculate byte-length of a void* UTF16 string.
** sqlite3utf8CharLen() - Calculate char-length of a char* UTF8 string.
** sqlite3utf8LikeCompare() - Do a LIKE match given two UTF8 char* strings.
**
*/
#include "sqliteInt.h"
#include <assert.h>
#include "vdbeInt.h"
/*
** The following constant value is used by the SQLITE_BIGENDIAN and
** SQLITE_LITTLEENDIAN macros.
*/
const int sqlite3one = 1;
/*
** This table maps from the first byte of a UTF-8 character to the number
** of trailing bytes expected. A value '4' indicates that the table key
** is not a legal first byte for a UTF-8 character.
*/
static const u8 xtra_utf8_bytes[256] = {
/* 0xxxxxxx */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 10wwwwww */
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
/* 110yyyyy */
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
/* 1110zzzz */
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
/* 11110yyy */
3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
};
/*
** This table maps from the number of trailing bytes in a UTF-8 character
** to an integer constant that is effectively calculated for each character
** read by a naive implementation of a UTF-8 character reader. The code
** in the READ_UTF8 macro explains things best.
*/
static const int xtra_utf8_bits[] = {
0,
12416, /* (0xC0 << 6) + (0x80) */
925824, /* (0xE0 << 12) + (0x80 << 6) + (0x80) */
63447168 /* (0xF0 << 18) + (0x80 << 12) + (0x80 << 6) + 0x80 */
};
/*
** If a UTF-8 character contains N bytes extra bytes (N bytes follow
** the initial byte so that the total character length is N+1) then
** masking the character with utf8_mask[N] must produce a non-zero
** result. Otherwise, we have an (illegal) overlong encoding.
*/
static const int utf_mask[] = {
0x00000000,
0xffffff80,
0xfffff800,
0xffff0000,
};
#define READ_UTF8(zIn, c) { \
int xtra; \
c = *(zIn)++; \
xtra = xtra_utf8_bytes[c]; \
switch( xtra ){ \
case 4: c = (int)0xFFFD; break; \
case 3: c = (c<<6) + *(zIn)++; \
case 2: c = (c<<6) + *(zIn)++; \
case 1: c = (c<<6) + *(zIn)++; \
c -= xtra_utf8_bits[xtra]; \
if( (utf_mask[xtra]&c)==0 \
|| (c&0xFFFFF800)==0xD800 \
|| (c&0xFFFFFFFE)==0xFFFE ){ c = 0xFFFD; } \
} \
}
int sqlite3ReadUtf8(const unsigned char *z){
int c;
READ_UTF8(z, c);
return c;
}
#define SKIP_UTF8(zIn) { \
zIn += (xtra_utf8_bytes[*(u8 *)zIn] + 1); \
}
#define WRITE_UTF8(zOut, c) { \
if( c<0x00080 ){ \
*zOut++ = (c&0xFF); \
} \
else if( c<0x00800 ){ \
*zOut++ = 0xC0 + ((c>>6)&0x1F); \
*zOut++ = 0x80 + (c & 0x3F); \
} \
else if( c<0x10000 ){ \
*zOut++ = 0xE0 + ((c>>12)&0x0F); \
*zOut++ = 0x80 + ((c>>6) & 0x3F); \
*zOut++ = 0x80 + (c & 0x3F); \
}else{ \
*zOut++ = 0xF0 + ((c>>18) & 0x07); \
*zOut++ = 0x80 + ((c>>12) & 0x3F); \
*zOut++ = 0x80 + ((c>>6) & 0x3F); \
*zOut++ = 0x80 + (c & 0x3F); \
} \
}
#define WRITE_UTF16LE(zOut, c) { \
if( c<=0xFFFF ){ \
*zOut++ = (c&0x00FF); \
*zOut++ = ((c>>8)&0x00FF); \
}else{ \
*zOut++ = (((c>>10)&0x003F) + (((c-0x10000)>>10)&0x00C0)); \
*zOut++ = (0x00D8 + (((c-0x10000)>>18)&0x03)); \
*zOut++ = (c&0x00FF); \
*zOut++ = (0x00DC + ((c>>8)&0x03)); \
} \
}
#define WRITE_UTF16BE(zOut, c) { \
if( c<=0xFFFF ){ \
*zOut++ = ((c>>8)&0x00FF); \
*zOut++ = (c&0x00FF); \
}else{ \
*zOut++ = (0x00D8 + (((c-0x10000)>>18)&0x03)); \
*zOut++ = (((c>>10)&0x003F) + (((c-0x10000)>>10)&0x00C0)); \
*zOut++ = (0x00DC + ((c>>8)&0x03)); \
*zOut++ = (c&0x00FF); \
} \
}
#define READ_UTF16LE(zIn, c){ \
c = (*zIn++); \
c += ((*zIn++)<<8); \
if( c>=0xD800 && c<=0xE000 ){ \
int c2 = (*zIn++); \
c2 += ((*zIn++)<<8); \
c = (c2&0x03FF) + ((c&0x003F)<<10) + (((c&0x03C0)+0x0040)<<10); \
if( (c & 0xFFFF0000)==0 ) c = 0xFFFD; \
} \
}
#define READ_UTF16BE(zIn, c){ \
c = ((*zIn++)<<8); \
c += (*zIn++); \
if( c>=0xD800 && c<=0xE000 ){ \
int c2 = ((*zIn++)<<8); \
c2 += (*zIn++); \
c = (c2&0x03FF) + ((c&0x003F)<<10) + (((c&0x03C0)+0x0040)<<10); \
if( (c & 0xFFFF0000)==0 ) c = 0xFFFD; \
} \
}
#define SKIP_UTF16BE(zIn){ \
if( *zIn>=0xD8 && (*zIn<0xE0 || (*zIn==0xE0 && *(zIn+1)==0x00)) ){ \
zIn += 4; \
}else{ \
zIn += 2; \
} \
}
#define SKIP_UTF16LE(zIn){ \
zIn++; \
if( *zIn>=0xD8 && (*zIn<0xE0 || (*zIn==0xE0 && *(zIn-1)==0x00)) ){ \
zIn += 3; \
}else{ \
zIn += 1; \
} \
}
#define RSKIP_UTF16LE(zIn){ \
if( *zIn>=0xD8 && (*zIn<0xE0 || (*zIn==0xE0 && *(zIn-1)==0x00)) ){ \
zIn -= 4; \
}else{ \
zIn -= 2; \
} \
}
#define RSKIP_UTF16BE(zIn){ \
zIn--; \
if( *zIn>=0xD8 && (*zIn<0xE0 || (*zIn==0xE0 && *(zIn+1)==0x00)) ){ \
zIn -= 3; \
}else{ \
zIn -= 1; \
} \
}
/*
** If the TRANSLATE_TRACE macro is defined, the value of each Mem is
** printed on stderr on the way into and out of sqlite3VdbeMemTranslate().
*/
/* #define TRANSLATE_TRACE 1 */
#ifndef SQLITE_OMIT_UTF16
/*
** This routine transforms the internal text encoding used by pMem to
** desiredEnc. It is an error if the string is already of the desired
** encoding, or if *pMem does not contain a string value.
*/
int sqlite3VdbeMemTranslate(Mem *pMem, u8 desiredEnc){
unsigned char zShort[NBFS]; /* Temporary short output buffer */
int len; /* Maximum length of output string in bytes */
unsigned char *zOut; /* Output buffer */
unsigned char *zIn; /* Input iterator */
unsigned char *zTerm; /* End of input */
unsigned char *z; /* Output iterator */
unsigned int c;
assert( pMem->flags&MEM_Str );
assert( pMem->enc!=desiredEnc );
assert( pMem->enc!=0 );
assert( pMem->n>=0 );
#if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
{
char zBuf[100];
sqlite3VdbeMemPrettyPrint(pMem, zBuf);
fprintf(stderr, "INPUT: %s\n", zBuf);
}
#endif
/* If the translation is between UTF-16 little and big endian, then
** all that is required is to swap the byte order. This case is handled
** differently from the others.
*/
if( pMem->enc!=SQLITE_UTF8 && desiredEnc!=SQLITE_UTF8 ){
u8 temp;
int rc;
rc = sqlite3VdbeMemMakeWriteable(pMem);
if( rc!=SQLITE_OK ){
assert( rc==SQLITE_NOMEM );
return SQLITE_NOMEM;
}
zIn = (u8*)pMem->z;
zTerm = &zIn[pMem->n];
while( zIn<zTerm ){
temp = *zIn;
*zIn = *(zIn+1);
zIn++;
*zIn++ = temp;
}
pMem->enc = desiredEnc;
goto translate_out;
}
/* Set len to the maximum number of bytes required in the output buffer. */
if( desiredEnc==SQLITE_UTF8 ){
/* When converting from UTF-16, the maximum growth results from
** translating a 2-byte character to a 4-byte UTF-8 character.
** A single byte is required for the output string
** nul-terminator.
*/
len = pMem->n * 2 + 1;
}else{
/* When converting from UTF-8 to UTF-16 the maximum growth is caused
** when a 1-byte UTF-8 character is translated into a 2-byte UTF-16
** character. Two bytes are required in the output buffer for the
** nul-terminator.
*/
len = pMem->n * 2 + 2;
}
/* Set zIn to point at the start of the input buffer and zTerm to point 1
** byte past the end.
**
** Variable zOut is set to point at the output buffer. This may be space
** obtained from malloc(), or Mem.zShort, if it large enough and not in
** use, or the zShort array on the stack (see above).
*/
zIn = (u8*)pMem->z;
zTerm = &zIn[pMem->n];
if( len>NBFS ){
zOut = sqliteMallocRaw(len);
if( !zOut ) return SQLITE_NOMEM;
}else{
zOut = zShort;
}
z = zOut;
if( pMem->enc==SQLITE_UTF8 ){
if( desiredEnc==SQLITE_UTF16LE ){
/* UTF-8 -> UTF-16 Little-endian */
while( zIn<zTerm ){
READ_UTF8(zIn, c);
WRITE_UTF16LE(z, c);
}
}else{
assert( desiredEnc==SQLITE_UTF16BE );
/* UTF-8 -> UTF-16 Big-endian */
while( zIn<zTerm ){
READ_UTF8(zIn, c);
WRITE_UTF16BE(z, c);
}
}
pMem->n = z - zOut;
*z++ = 0;
}else{
assert( desiredEnc==SQLITE_UTF8 );
if( pMem->enc==SQLITE_UTF16LE ){
/* UTF-16 Little-endian -> UTF-8 */
while( zIn<zTerm ){
READ_UTF16LE(zIn, c);
WRITE_UTF8(z, c);
}
}else{
/* UTF-16 Little-endian -> UTF-8 */
while( zIn<zTerm ){
READ_UTF16BE(zIn, c);
WRITE_UTF8(z, c);
}
}
pMem->n = z - zOut;
}
*z = 0;
assert( (pMem->n+(desiredEnc==SQLITE_UTF8?1:2))<=len );
sqlite3VdbeMemRelease(pMem);
pMem->flags &= ~(MEM_Static|MEM_Dyn|MEM_Ephem|MEM_Short);
pMem->enc = desiredEnc;
if( zOut==zShort ){
memcpy(pMem->zShort, zOut, len);
zOut = (u8*)pMem->zShort;
pMem->flags |= (MEM_Term|MEM_Short);
}else{
pMem->flags |= (MEM_Term|MEM_Dyn);
}
pMem->z = (char*)zOut;
translate_out:
#if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
{
char zBuf[100];
sqlite3VdbeMemPrettyPrint(pMem, zBuf);
fprintf(stderr, "OUTPUT: %s\n", zBuf);
}
#endif
return SQLITE_OK;
}
/*
** This routine checks for a byte-order mark at the beginning of the
** UTF-16 string stored in *pMem. If one is present, it is removed and
** the encoding of the Mem adjusted. This routine does not do any
** byte-swapping, it just sets Mem.enc appropriately.
**
** The allocation (static, dynamic etc.) and encoding of the Mem may be
** changed by this function.
*/
int sqlite3VdbeMemHandleBom(Mem *pMem){
int rc = SQLITE_OK;
u8 bom = 0;
if( pMem->n<0 || pMem->n>1 ){
u8 b1 = *(u8 *)pMem->z;
u8 b2 = *(((u8 *)pMem->z) + 1);
if( b1==0xFE && b2==0xFF ){
bom = SQLITE_UTF16BE;
}
if( b1==0xFF && b2==0xFE ){
bom = SQLITE_UTF16LE;
}
}
if( bom ){
/* This function is called as soon as a string is stored in a Mem*,
** from within sqlite3VdbeMemSetStr(). At that point it is not possible
** for the string to be stored in Mem.zShort, or for it to be stored
** in dynamic memory with no destructor.
*/
assert( !(pMem->flags&MEM_Short) );
assert( !(pMem->flags&MEM_Dyn) || pMem->xDel );
if( pMem->flags & MEM_Dyn ){
void (*xDel)(void*) = pMem->xDel;
char *z = pMem->z;
pMem->z = 0;
pMem->xDel = 0;
rc = sqlite3VdbeMemSetStr(pMem, &z[2], pMem->n-2, bom, SQLITE_TRANSIENT);
xDel(z);
}else{
rc = sqlite3VdbeMemSetStr(pMem, &pMem->z[2], pMem->n-2, bom,
SQLITE_TRANSIENT);
}
}
return rc;
}
#endif /* SQLITE_OMIT_UTF16 */
/*
** pZ is a UTF-8 encoded unicode string. If nByte is less than zero,
** return the number of unicode characters in pZ up to (but not including)
** the first 0x00 byte. If nByte is not less than zero, return the
** number of unicode characters in the first nByte of pZ (or up to
** the first 0x00, whichever comes first).
*/
int sqlite3utf8CharLen(const char *z, int nByte){
int r = 0;
const char *zTerm;
if( nByte>=0 ){
zTerm = &z[nByte];
}else{
zTerm = (const char *)(-1);
}
assert( z<=zTerm );
while( *z!=0 && z<zTerm ){
SKIP_UTF8(z);
r++;
}
return r;
}
#ifndef SQLITE_OMIT_UTF16
/*
** Convert a UTF-16 string in the native encoding into a UTF-8 string.
** Memory to hold the UTF-8 string is obtained from malloc and must be
** freed by the calling function.
**
** NULL is returned if there is an allocation error.
*/
char *sqlite3utf16to8(const void *z, int nByte){
Mem m;
memset(&m, 0, sizeof(m));
sqlite3VdbeMemSetStr(&m, z, nByte, SQLITE_UTF16NATIVE, SQLITE_STATIC);
sqlite3VdbeChangeEncoding(&m, SQLITE_UTF8);
assert( (m.flags & MEM_Term)!=0 || sqlite3MallocFailed() );
assert( (m.flags & MEM_Str)!=0 || sqlite3MallocFailed() );
return (m.flags & MEM_Dyn)!=0 ? m.z : sqliteStrDup(m.z);
}
/*
** pZ is a UTF-16 encoded unicode string. If nChar is less than zero,
** return the number of bytes up to (but not including), the first pair
** of consecutive 0x00 bytes in pZ. If nChar is not less than zero,
** then return the number of bytes in the first nChar unicode characters
** in pZ (or up until the first pair of 0x00 bytes, whichever comes first).
*/
int sqlite3utf16ByteLen(const void *zIn, int nChar){
unsigned int c = 1;
char const *z = zIn;
int n = 0;
if( SQLITE_UTF16NATIVE==SQLITE_UTF16BE ){
/* Using an "if (SQLITE_UTF16NATIVE==SQLITE_UTF16BE)" construct here
** and in other parts of this file means that at one branch will
** not be covered by coverage testing on any single host. But coverage
** will be complete if the tests are run on both a little-endian and
** big-endian host. Because both the UTF16NATIVE and SQLITE_UTF16BE
** macros are constant at compile time the compiler can determine
** which branch will be followed. It is therefore assumed that no runtime
** penalty is paid for this "if" statement.
*/
while( c && ((nChar<0) || n<nChar) ){
READ_UTF16BE(z, c);
n++;
}
}else{
while( c && ((nChar<0) || n<nChar) ){
READ_UTF16LE(z, c);
n++;
}
}
return (z-(char const *)zIn)-((c==0)?2:0);
}
/*
** UTF-16 implementation of the substr()
*/
void sqlite3utf16Substr(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int y, z;
unsigned char const *zStr;
unsigned char const *zStrEnd;
unsigned char const *zStart;
unsigned char const *zEnd;
int i;
zStr = (unsigned char const *)sqlite3_value_text16(argv[0]);
zStrEnd = &zStr[sqlite3_value_bytes16(argv[0])];
y = sqlite3_value_int(argv[1]);
z = sqlite3_value_int(argv[2]);
if( y>0 ){
y = y-1;
zStart = zStr;
if( SQLITE_UTF16BE==SQLITE_UTF16NATIVE ){
for(i=0; i<y && zStart<zStrEnd; i++) SKIP_UTF16BE(zStart);
}else{
for(i=0; i<y && zStart<zStrEnd; i++) SKIP_UTF16LE(zStart);
}
}else{
zStart = zStrEnd;
if( SQLITE_UTF16BE==SQLITE_UTF16NATIVE ){
for(i=y; i<0 && zStart>zStr; i++) RSKIP_UTF16BE(zStart);
}else{
for(i=y; i<0 && zStart>zStr; i++) RSKIP_UTF16LE(zStart);
}
for(; i<0; i++) z -= 1;
}
zEnd = zStart;
if( SQLITE_UTF16BE==SQLITE_UTF16NATIVE ){
for(i=0; i<z && zEnd<zStrEnd; i++) SKIP_UTF16BE(zEnd);
}else{
for(i=0; i<z && zEnd<zStrEnd; i++) SKIP_UTF16LE(zEnd);
}
sqlite3_result_text16(context, zStart, zEnd-zStart, SQLITE_TRANSIENT);
}
#if defined(SQLITE_TEST)
/*
** This routine is called from the TCL test function "translate_selftest".
** It checks that the primitives for serializing and deserializing
** characters in each encoding are inverses of each other.
*/
void sqlite3utfSelfTest(){
unsigned int i, t;
unsigned char zBuf[20];
unsigned char *z;
int n;
unsigned int c;
for(i=0; i<0x00110000; i++){
z = zBuf;
WRITE_UTF8(z, i);
n = z-zBuf;
z = zBuf;
READ_UTF8(z, c);
t = i;
if( i>=0xD800 && i<=0xDFFF ) t = 0xFFFD;
if( (i&0xFFFFFFFE)==0xFFFE ) t = 0xFFFD;
assert( c==t );
assert( (z-zBuf)==n );
}
for(i=0; i<0x00110000; i++){
if( i>=0xD800 && i<=0xE000 ) continue;
z = zBuf;
WRITE_UTF16LE(z, i);
n = z-zBuf;
z = zBuf;
READ_UTF16LE(z, c);
assert( c==i );
assert( (z-zBuf)==n );
}
for(i=0; i<0x00110000; i++){
if( i>=0xD800 && i<=0xE000 ) continue;
z = zBuf;
WRITE_UTF16BE(z, i);
n = z-zBuf;
z = zBuf;
READ_UTF16BE(z, c);
assert( c==i );
assert( (z-zBuf)==n );
}
}
#endif /* SQLITE_TEST */
#endif /* SQLITE_OMIT_UTF16 */