Annotation of embedaddon/sqlite3/ext/fts3/fts3_icu.c, revision 1.1
1.1 ! misho 1: /*
! 2: ** 2007 June 22
! 3: **
! 4: ** The author disclaims copyright to this source code. In place of
! 5: ** a legal notice, here is a blessing:
! 6: **
! 7: ** May you do good and not evil.
! 8: ** May you find forgiveness for yourself and forgive others.
! 9: ** May you share freely, never taking more than you give.
! 10: **
! 11: *************************************************************************
! 12: ** This file implements a tokenizer for fts3 based on the ICU library.
! 13: */
! 14: #include "fts3Int.h"
! 15: #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
! 16: #ifdef SQLITE_ENABLE_ICU
! 17:
! 18: #include <assert.h>
! 19: #include <string.h>
! 20: #include "fts3_tokenizer.h"
! 21:
! 22: #include <unicode/ubrk.h>
! 23: #include <unicode/ucol.h>
! 24: #include <unicode/ustring.h>
! 25: #include <unicode/utf16.h>
! 26:
! 27: typedef struct IcuTokenizer IcuTokenizer;
! 28: typedef struct IcuCursor IcuCursor;
! 29:
! 30: struct IcuTokenizer {
! 31: sqlite3_tokenizer base;
! 32: char *zLocale;
! 33: };
! 34:
! 35: struct IcuCursor {
! 36: sqlite3_tokenizer_cursor base;
! 37:
! 38: UBreakIterator *pIter; /* ICU break-iterator object */
! 39: int nChar; /* Number of UChar elements in pInput */
! 40: UChar *aChar; /* Copy of input using utf-16 encoding */
! 41: int *aOffset; /* Offsets of each character in utf-8 input */
! 42:
! 43: int nBuffer;
! 44: char *zBuffer;
! 45:
! 46: int iToken;
! 47: };
! 48:
! 49: /*
! 50: ** Create a new tokenizer instance.
! 51: */
! 52: static int icuCreate(
! 53: int argc, /* Number of entries in argv[] */
! 54: const char * const *argv, /* Tokenizer creation arguments */
! 55: sqlite3_tokenizer **ppTokenizer /* OUT: Created tokenizer */
! 56: ){
! 57: IcuTokenizer *p;
! 58: int n = 0;
! 59:
! 60: if( argc>0 ){
! 61: n = strlen(argv[0])+1;
! 62: }
! 63: p = (IcuTokenizer *)sqlite3_malloc(sizeof(IcuTokenizer)+n);
! 64: if( !p ){
! 65: return SQLITE_NOMEM;
! 66: }
! 67: memset(p, 0, sizeof(IcuTokenizer));
! 68:
! 69: if( n ){
! 70: p->zLocale = (char *)&p[1];
! 71: memcpy(p->zLocale, argv[0], n);
! 72: }
! 73:
! 74: *ppTokenizer = (sqlite3_tokenizer *)p;
! 75:
! 76: return SQLITE_OK;
! 77: }
! 78:
! 79: /*
! 80: ** Destroy a tokenizer
! 81: */
! 82: static int icuDestroy(sqlite3_tokenizer *pTokenizer){
! 83: IcuTokenizer *p = (IcuTokenizer *)pTokenizer;
! 84: sqlite3_free(p);
! 85: return SQLITE_OK;
! 86: }
! 87:
! 88: /*
! 89: ** Prepare to begin tokenizing a particular string. The input
! 90: ** string to be tokenized is pInput[0..nBytes-1]. A cursor
! 91: ** used to incrementally tokenize this string is returned in
! 92: ** *ppCursor.
! 93: */
! 94: static int icuOpen(
! 95: sqlite3_tokenizer *pTokenizer, /* The tokenizer */
! 96: const char *zInput, /* Input string */
! 97: int nInput, /* Length of zInput in bytes */
! 98: sqlite3_tokenizer_cursor **ppCursor /* OUT: Tokenization cursor */
! 99: ){
! 100: IcuTokenizer *p = (IcuTokenizer *)pTokenizer;
! 101: IcuCursor *pCsr;
! 102:
! 103: const int32_t opt = U_FOLD_CASE_DEFAULT;
! 104: UErrorCode status = U_ZERO_ERROR;
! 105: int nChar;
! 106:
! 107: UChar32 c;
! 108: int iInput = 0;
! 109: int iOut = 0;
! 110:
! 111: *ppCursor = 0;
! 112:
! 113: if( nInput<0 ){
! 114: nInput = strlen(zInput);
! 115: }
! 116: nChar = nInput+1;
! 117: pCsr = (IcuCursor *)sqlite3_malloc(
! 118: sizeof(IcuCursor) + /* IcuCursor */
! 119: nChar * sizeof(UChar) + /* IcuCursor.aChar[] */
! 120: (nChar+1) * sizeof(int) /* IcuCursor.aOffset[] */
! 121: );
! 122: if( !pCsr ){
! 123: return SQLITE_NOMEM;
! 124: }
! 125: memset(pCsr, 0, sizeof(IcuCursor));
! 126: pCsr->aChar = (UChar *)&pCsr[1];
! 127: pCsr->aOffset = (int *)&pCsr->aChar[nChar];
! 128:
! 129: pCsr->aOffset[iOut] = iInput;
! 130: U8_NEXT(zInput, iInput, nInput, c);
! 131: while( c>0 ){
! 132: int isError = 0;
! 133: c = u_foldCase(c, opt);
! 134: U16_APPEND(pCsr->aChar, iOut, nChar, c, isError);
! 135: if( isError ){
! 136: sqlite3_free(pCsr);
! 137: return SQLITE_ERROR;
! 138: }
! 139: pCsr->aOffset[iOut] = iInput;
! 140:
! 141: if( iInput<nInput ){
! 142: U8_NEXT(zInput, iInput, nInput, c);
! 143: }else{
! 144: c = 0;
! 145: }
! 146: }
! 147:
! 148: pCsr->pIter = ubrk_open(UBRK_WORD, p->zLocale, pCsr->aChar, iOut, &status);
! 149: if( !U_SUCCESS(status) ){
! 150: sqlite3_free(pCsr);
! 151: return SQLITE_ERROR;
! 152: }
! 153: pCsr->nChar = iOut;
! 154:
! 155: ubrk_first(pCsr->pIter);
! 156: *ppCursor = (sqlite3_tokenizer_cursor *)pCsr;
! 157: return SQLITE_OK;
! 158: }
! 159:
! 160: /*
! 161: ** Close a tokenization cursor previously opened by a call to icuOpen().
! 162: */
! 163: static int icuClose(sqlite3_tokenizer_cursor *pCursor){
! 164: IcuCursor *pCsr = (IcuCursor *)pCursor;
! 165: ubrk_close(pCsr->pIter);
! 166: sqlite3_free(pCsr->zBuffer);
! 167: sqlite3_free(pCsr);
! 168: return SQLITE_OK;
! 169: }
! 170:
! 171: /*
! 172: ** Extract the next token from a tokenization cursor.
! 173: */
! 174: static int icuNext(
! 175: sqlite3_tokenizer_cursor *pCursor, /* Cursor returned by simpleOpen */
! 176: const char **ppToken, /* OUT: *ppToken is the token text */
! 177: int *pnBytes, /* OUT: Number of bytes in token */
! 178: int *piStartOffset, /* OUT: Starting offset of token */
! 179: int *piEndOffset, /* OUT: Ending offset of token */
! 180: int *piPosition /* OUT: Position integer of token */
! 181: ){
! 182: IcuCursor *pCsr = (IcuCursor *)pCursor;
! 183:
! 184: int iStart = 0;
! 185: int iEnd = 0;
! 186: int nByte = 0;
! 187:
! 188: while( iStart==iEnd ){
! 189: UChar32 c;
! 190:
! 191: iStart = ubrk_current(pCsr->pIter);
! 192: iEnd = ubrk_next(pCsr->pIter);
! 193: if( iEnd==UBRK_DONE ){
! 194: return SQLITE_DONE;
! 195: }
! 196:
! 197: while( iStart<iEnd ){
! 198: int iWhite = iStart;
! 199: U8_NEXT(pCsr->aChar, iWhite, pCsr->nChar, c);
! 200: if( u_isspace(c) ){
! 201: iStart = iWhite;
! 202: }else{
! 203: break;
! 204: }
! 205: }
! 206: assert(iStart<=iEnd);
! 207: }
! 208:
! 209: do {
! 210: UErrorCode status = U_ZERO_ERROR;
! 211: if( nByte ){
! 212: char *zNew = sqlite3_realloc(pCsr->zBuffer, nByte);
! 213: if( !zNew ){
! 214: return SQLITE_NOMEM;
! 215: }
! 216: pCsr->zBuffer = zNew;
! 217: pCsr->nBuffer = nByte;
! 218: }
! 219:
! 220: u_strToUTF8(
! 221: pCsr->zBuffer, pCsr->nBuffer, &nByte, /* Output vars */
! 222: &pCsr->aChar[iStart], iEnd-iStart, /* Input vars */
! 223: &status /* Output success/failure */
! 224: );
! 225: } while( nByte>pCsr->nBuffer );
! 226:
! 227: *ppToken = pCsr->zBuffer;
! 228: *pnBytes = nByte;
! 229: *piStartOffset = pCsr->aOffset[iStart];
! 230: *piEndOffset = pCsr->aOffset[iEnd];
! 231: *piPosition = pCsr->iToken++;
! 232:
! 233: return SQLITE_OK;
! 234: }
! 235:
! 236: /*
! 237: ** The set of routines that implement the simple tokenizer
! 238: */
! 239: static const sqlite3_tokenizer_module icuTokenizerModule = {
! 240: 0, /* iVersion */
! 241: icuCreate, /* xCreate */
! 242: icuDestroy, /* xCreate */
! 243: icuOpen, /* xOpen */
! 244: icuClose, /* xClose */
! 245: icuNext, /* xNext */
! 246: };
! 247:
! 248: /*
! 249: ** Set *ppModule to point at the implementation of the ICU tokenizer.
! 250: */
! 251: void sqlite3Fts3IcuTokenizerModule(
! 252: sqlite3_tokenizer_module const**ppModule
! 253: ){
! 254: *ppModule = &icuTokenizerModule;
! 255: }
! 256:
! 257: #endif /* defined(SQLITE_ENABLE_ICU) */
! 258: #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
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