utf.c.svn-base
上传用户:sunhongbo
上传日期:2022-01-25
资源大小:3010k
文件大小:17k
- /*
- ** 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: utf.c,v 1.61 2008/03/28 15:44:10 danielk1977 Exp $
- **
- ** 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
- **
- */
- #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 lookup table is used to help decode the first byte of
- ** a multi-byte UTF8 character.
- */
- static const unsigned char sqlite3UtfTrans1[] = {
- 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
- 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
- 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
- 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
- 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
- 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
- 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
- 0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
- };
- #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;
- }
- }
- /*
- ** Translate a single UTF-8 character. Return the unicode value.
- **
- ** During translation, assume that the byte that zTerm points
- ** is a 0x00.
- **
- ** Write a pointer to the next unread byte back into *pzNext.
- **
- ** Notes On Invalid UTF-8:
- **
- ** * This routine never allows a 7-bit character (0x00 through 0x7f) to
- ** be encoded as a multi-byte character. Any multi-byte character that
- ** attempts to encode a value between 0x00 and 0x7f is rendered as 0xfffd.
- **
- ** * This routine never allows a UTF16 surrogate value to be encoded.
- ** If a multi-byte character attempts to encode a value between
- ** 0xd800 and 0xe000 then it is rendered as 0xfffd.
- **
- ** * Bytes in the range of 0x80 through 0xbf which occur as the first
- ** byte of a character are interpreted as single-byte characters
- ** and rendered as themselves even though they are technically
- ** invalid characters.
- **
- ** * This routine accepts an infinite number of different UTF8 encodings
- ** for unicode values 0x80 and greater. It do not change over-length
- ** encodings to 0xfffd as some systems recommend.
- */
- int sqlite3Utf8Read(
- const unsigned char *z, /* First byte of UTF-8 character */
- const unsigned char *zTerm, /* Pretend this byte is 0x00 */
- const unsigned char **pzNext /* Write first byte past UTF-8 char here */
- ){
- int c = *(z++);
- if( c>=0xc0 ){
- c = sqlite3UtfTrans1[c-0xc0];
- while( z!=zTerm && (*z & 0xc0)==0x80 ){
- c = (c<<6) + (0x3f & *(z++));
- }
- if( c<0x80
- || (c&0xFFFFF800)==0xD800
- || (c&0xFFFFFFFE)==0xFFFE ){ c = 0xFFFD; }
- }
- *pzNext = z;
- return c;
- }
- /*
- ** 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){
- 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->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
- 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: %sn", 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, space obtained
- ** from sqlite3_malloc().
- */
- zIn = (u8*)pMem->z;
- zTerm = &zIn[pMem->n];
- zOut = sqlite3DbMallocRaw(pMem->db, len);
- if( !zOut ){
- return SQLITE_NOMEM;
- }
- z = zOut;
- if( pMem->enc==SQLITE_UTF8 ){
- if( desiredEnc==SQLITE_UTF16LE ){
- /* UTF-8 -> UTF-16 Little-endian */
- while( zIn<zTerm ){
- c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn);
- WRITE_UTF16LE(z, c);
- }
- }else{
- assert( desiredEnc==SQLITE_UTF16BE );
- /* UTF-8 -> UTF-16 Big-endian */
- while( zIn<zTerm ){
- c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn);
- 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);
- pMem->enc = desiredEnc;
- pMem->flags |= (MEM_Term|MEM_Dyn);
- pMem->z = (char*)zOut;
- pMem->zMalloc = pMem->z;
- translate_out:
- #if defined(TRANSLATE_TRACE) && defined(SQLITE_DEBUG)
- {
- char zBuf[100];
- sqlite3VdbeMemPrettyPrint(pMem, zBuf);
- fprintf(stderr, "OUTPUT: %sn", 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 ){
- rc = sqlite3VdbeMemMakeWriteable(pMem);
- if( rc==SQLITE_OK ){
- pMem->n -= 2;
- memmove(pMem->z, &pMem->z[2], pMem->n);
- pMem->z[pMem->n] = ' ';
- pMem->z[pMem->n+1] = ' ';
- pMem->flags |= MEM_Term;
- pMem->enc = bom;
- }
- }
- 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 *zIn, int nByte){
- int r = 0;
- const u8 *z = (const u8*)zIn;
- const u8 *zTerm;
- if( nByte>=0 ){
- zTerm = &z[nByte];
- }else{
- zTerm = (const u8*)(-1);
- }
- assert( z<=zTerm );
- while( *z!=0 && z<zTerm ){
- SQLITE_SKIP_UTF8(z);
- r++;
- }
- return r;
- }
- /* This test function is not currently used by the automated test-suite.
- ** Hence it is only available in debug builds.
- */
- #if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
- /*
- ** Translate UTF-8 to UTF-8.
- **
- ** This has the effect of making sure that the string is well-formed
- ** UTF-8. Miscoded characters are removed.
- **
- ** The translation is done in-place (since it is impossible for the
- ** correct UTF-8 encoding to be longer than a malformed encoding).
- */
- int sqlite3Utf8To8(unsigned char *zIn){
- unsigned char *zOut = zIn;
- unsigned char *zStart = zIn;
- unsigned char *zTerm;
- u32 c;
- while( zIn[0] ){
- c = sqlite3Utf8Read(zIn, zTerm, (const u8**)&zIn);
- if( c!=0xfffd ){
- WRITE_UTF8(zOut, c);
- }
- }
- *zOut = 0;
- return zOut - zStart;
- }
- #endif
- #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 sqlite3_malloc and must
- ** be freed by the calling function.
- **
- ** NULL is returned if there is an allocation error.
- */
- char *sqlite3Utf16to8(sqlite3 *db, const void *z, int nByte){
- Mem m;
- memset(&m, 0, sizeof(m));
- m.db = db;
- sqlite3VdbeMemSetStr(&m, z, nByte, SQLITE_UTF16NATIVE, SQLITE_STATIC);
- sqlite3VdbeChangeEncoding(&m, SQLITE_UTF8);
- if( db->mallocFailed ){
- sqlite3VdbeMemRelease(&m);
- m.z = 0;
- }
- assert( (m.flags & MEM_Term)!=0 || db->mallocFailed );
- assert( (m.flags & MEM_Str)!=0 || db->mallocFailed );
- return (m.flags & MEM_Dyn)!=0 ? m.z : sqlite3DbStrDup(db, 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);
- }
- #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;
- unsigned char *zTerm;
- int n;
- unsigned int c;
- for(i=0; i<0x00110000; i++){
- z = zBuf;
- WRITE_UTF8(z, i);
- n = z-zBuf;
- z[0] = 0;
- zTerm = z;
- z = zBuf;
- c = sqlite3Utf8Read(z, zTerm, (const u8**)&z);
- 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[0] = 0;
- 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[0] = 0;
- z = zBuf;
- READ_UTF16BE(z, c);
- assert( c==i );
- assert( (z-zBuf)==n );
- }
- }
- #endif /* SQLITE_TEST */
- #endif /* SQLITE_OMIT_UTF16 */