engine/sqlite/src/utf.cpp
changeset 2 29cda98b007e
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/engine/sqlite/src/utf.cpp	Thu Feb 25 14:29:19 2010 +0000
@@ -0,0 +1,545 @@
+/*
+** 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.cpp 1282 2008-11-13 09:31:33Z LarsPson $
+**
+** 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){
+  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->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:  %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 sqlite3_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 = (unsigned char*)sqlite3DbMallocRaw(pMem->db, 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 ){
+        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|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 *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, (const char*)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 = (const char*)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 */