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| 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 ** |
| 13 ** This is part of an SQLite module implementing full-text search. |
| 14 ** This particular file implements the generic tokenizer interface. |
| 15 */ |
| 16 |
| 17 /* |
| 18 ** The code in this file is only compiled if: |
| 19 ** |
| 20 ** * The FTS3 module is being built as an extension |
| 21 ** (in which case SQLITE_CORE is not defined), or |
| 22 ** |
| 23 ** * The FTS3 module is being built into the core of |
| 24 ** SQLite (in which case SQLITE_ENABLE_FTS3 is defined). |
| 25 */ |
| 26 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) |
| 27 |
| 28 #include "sqlite3ext.h" |
| 29 #ifndef SQLITE_CORE |
| 30 SQLITE_EXTENSION_INIT1 |
| 31 #endif |
| 32 |
| 33 #include "fts3Int.h" |
| 34 #include <assert.h> |
| 35 #include <string.h> |
| 36 |
| 37 /* |
| 38 ** Implementation of the SQL scalar function for accessing the underlying |
| 39 ** hash table. This function may be called as follows: |
| 40 ** |
| 41 ** SELECT <function-name>(<key-name>); |
| 42 ** SELECT <function-name>(<key-name>, <pointer>); |
| 43 ** |
| 44 ** where <function-name> is the name passed as the second argument |
| 45 ** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer'). |
| 46 ** |
| 47 ** If the <pointer> argument is specified, it must be a blob value |
| 48 ** containing a pointer to be stored as the hash data corresponding |
| 49 ** to the string <key-name>. If <pointer> is not specified, then |
| 50 ** the string <key-name> must already exist in the has table. Otherwise, |
| 51 ** an error is returned. |
| 52 ** |
| 53 ** Whether or not the <pointer> argument is specified, the value returned |
| 54 ** is a blob containing the pointer stored as the hash data corresponding |
| 55 ** to string <key-name> (after the hash-table is updated, if applicable). |
| 56 */ |
| 57 static void scalarFunc( |
| 58 sqlite3_context *context, |
| 59 int argc, |
| 60 sqlite3_value **argv |
| 61 ){ |
| 62 Fts3Hash *pHash; |
| 63 void *pPtr = 0; |
| 64 const unsigned char *zName; |
| 65 int nName; |
| 66 |
| 67 assert( argc==1 || argc==2 ); |
| 68 |
| 69 pHash = (Fts3Hash *)sqlite3_user_data(context); |
| 70 |
| 71 zName = sqlite3_value_text(argv[0]); |
| 72 nName = sqlite3_value_bytes(argv[0])+1; |
| 73 |
| 74 if( argc==2 ){ |
| 75 void *pOld; |
| 76 int n = sqlite3_value_bytes(argv[1]); |
| 77 if( n!=sizeof(pPtr) ){ |
| 78 sqlite3_result_error(context, "argument type mismatch", -1); |
| 79 return; |
| 80 } |
| 81 pPtr = *(void **)sqlite3_value_blob(argv[1]); |
| 82 pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr); |
| 83 if( pOld==pPtr ){ |
| 84 sqlite3_result_error(context, "out of memory", -1); |
| 85 return; |
| 86 } |
| 87 }else{ |
| 88 pPtr = sqlite3Fts3HashFind(pHash, zName, nName); |
| 89 if( !pPtr ){ |
| 90 char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName); |
| 91 sqlite3_result_error(context, zErr, -1); |
| 92 sqlite3_free(zErr); |
| 93 return; |
| 94 } |
| 95 } |
| 96 |
| 97 sqlite3_result_blob(context, (void *)&pPtr, sizeof(pPtr), SQLITE_TRANSIENT); |
| 98 } |
| 99 |
| 100 int sqlite3Fts3IsIdChar(char c){ |
| 101 static const char isFtsIdChar[] = { |
| 102 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x */ |
| 103 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 1x */ |
| 104 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 2x */ |
| 105 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* 3x */ |
| 106 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 4x */ |
| 107 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, /* 5x */ |
| 108 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6x */ |
| 109 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, /* 7x */ |
| 110 }; |
| 111 return (c&0x80 || isFtsIdChar[(int)(c)]); |
| 112 } |
| 113 |
| 114 const char *sqlite3Fts3NextToken(const char *zStr, int *pn){ |
| 115 const char *z1; |
| 116 const char *z2 = 0; |
| 117 |
| 118 /* Find the start of the next token. */ |
| 119 z1 = zStr; |
| 120 while( z2==0 ){ |
| 121 char c = *z1; |
| 122 switch( c ){ |
| 123 case '\0': return 0; /* No more tokens here */ |
| 124 case '\'': |
| 125 case '"': |
| 126 case '`': { |
| 127 z2 = z1; |
| 128 while( *++z2 && (*z2!=c || *++z2==c) ); |
| 129 break; |
| 130 } |
| 131 case '[': |
| 132 z2 = &z1[1]; |
| 133 while( *z2 && z2[0]!=']' ) z2++; |
| 134 if( *z2 ) z2++; |
| 135 break; |
| 136 |
| 137 default: |
| 138 if( sqlite3Fts3IsIdChar(*z1) ){ |
| 139 z2 = &z1[1]; |
| 140 while( sqlite3Fts3IsIdChar(*z2) ) z2++; |
| 141 }else{ |
| 142 z1++; |
| 143 } |
| 144 } |
| 145 } |
| 146 |
| 147 *pn = (int)(z2-z1); |
| 148 return z1; |
| 149 } |
| 150 |
| 151 int sqlite3Fts3InitTokenizer( |
| 152 Fts3Hash *pHash, /* Tokenizer hash table */ |
| 153 const char *zArg, /* Tokenizer name */ |
| 154 sqlite3_tokenizer **ppTok, /* OUT: Tokenizer (if applicable) */ |
| 155 char **pzErr /* OUT: Set to malloced error message */ |
| 156 ){ |
| 157 int rc; |
| 158 char *z = (char *)zArg; |
| 159 int n; |
| 160 char *zCopy; |
| 161 char *zEnd; /* Pointer to nul-term of zCopy */ |
| 162 sqlite3_tokenizer_module *m; |
| 163 |
| 164 zCopy = sqlite3_mprintf("%s", zArg); |
| 165 if( !zCopy ) return SQLITE_NOMEM; |
| 166 zEnd = &zCopy[strlen(zCopy)]; |
| 167 |
| 168 z = (char *)sqlite3Fts3NextToken(zCopy, &n); |
| 169 z[n] = '\0'; |
| 170 sqlite3Fts3Dequote(z); |
| 171 |
| 172 m = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash,z,(int)strlen(z)+1); |
| 173 if( !m ){ |
| 174 *pzErr = sqlite3_mprintf("unknown tokenizer: %s", z); |
| 175 rc = SQLITE_ERROR; |
| 176 }else{ |
| 177 char const **aArg = 0; |
| 178 int iArg = 0; |
| 179 z = &z[n+1]; |
| 180 while( z<zEnd && (NULL!=(z = (char *)sqlite3Fts3NextToken(z, &n))) ){ |
| 181 int nNew = sizeof(char *)*(iArg+1); |
| 182 char const **aNew = (const char **)sqlite3_realloc((void *)aArg, nNew); |
| 183 if( !aNew ){ |
| 184 sqlite3_free(zCopy); |
| 185 sqlite3_free((void *)aArg); |
| 186 return SQLITE_NOMEM; |
| 187 } |
| 188 aArg = aNew; |
| 189 aArg[iArg++] = z; |
| 190 z[n] = '\0'; |
| 191 sqlite3Fts3Dequote(z); |
| 192 z = &z[n+1]; |
| 193 } |
| 194 rc = m->xCreate(iArg, aArg, ppTok); |
| 195 assert( rc!=SQLITE_OK || *ppTok ); |
| 196 if( rc!=SQLITE_OK ){ |
| 197 *pzErr = sqlite3_mprintf("unknown tokenizer"); |
| 198 }else{ |
| 199 (*ppTok)->pModule = m; |
| 200 } |
| 201 sqlite3_free((void *)aArg); |
| 202 } |
| 203 |
| 204 sqlite3_free(zCopy); |
| 205 return rc; |
| 206 } |
| 207 |
| 208 |
| 209 #ifdef SQLITE_TEST |
| 210 |
| 211 #include <tcl.h> |
| 212 #include <string.h> |
| 213 |
| 214 /* |
| 215 ** Implementation of a special SQL scalar function for testing tokenizers |
| 216 ** designed to be used in concert with the Tcl testing framework. This |
| 217 ** function must be called with two arguments: |
| 218 ** |
| 219 ** SELECT <function-name>(<key-name>, <input-string>); |
| 220 ** SELECT <function-name>(<key-name>, <pointer>); |
| 221 ** |
| 222 ** where <function-name> is the name passed as the second argument |
| 223 ** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer') |
| 224 ** concatenated with the string '_test' (e.g. 'fts3_tokenizer_test'). |
| 225 ** |
| 226 ** The return value is a string that may be interpreted as a Tcl |
| 227 ** list. For each token in the <input-string>, three elements are |
| 228 ** added to the returned list. The first is the token position, the |
| 229 ** second is the token text (folded, stemmed, etc.) and the third is the |
| 230 ** substring of <input-string> associated with the token. For example, |
| 231 ** using the built-in "simple" tokenizer: |
| 232 ** |
| 233 ** SELECT fts_tokenizer_test('simple', 'I don't see how'); |
| 234 ** |
| 235 ** will return the string: |
| 236 ** |
| 237 ** "{0 i I 1 dont don't 2 see see 3 how how}" |
| 238 ** |
| 239 */ |
| 240 static void testFunc( |
| 241 sqlite3_context *context, |
| 242 int argc, |
| 243 sqlite3_value **argv |
| 244 ){ |
| 245 Fts3Hash *pHash; |
| 246 sqlite3_tokenizer_module *p; |
| 247 sqlite3_tokenizer *pTokenizer = 0; |
| 248 sqlite3_tokenizer_cursor *pCsr = 0; |
| 249 |
| 250 const char *zErr = 0; |
| 251 |
| 252 const char *zName; |
| 253 int nName; |
| 254 const char *zInput; |
| 255 int nInput; |
| 256 |
| 257 const char *zArg = 0; |
| 258 |
| 259 const char *zToken; |
| 260 int nToken; |
| 261 int iStart; |
| 262 int iEnd; |
| 263 int iPos; |
| 264 |
| 265 Tcl_Obj *pRet; |
| 266 |
| 267 assert( argc==2 || argc==3 ); |
| 268 |
| 269 nName = sqlite3_value_bytes(argv[0]); |
| 270 zName = (const char *)sqlite3_value_text(argv[0]); |
| 271 nInput = sqlite3_value_bytes(argv[argc-1]); |
| 272 zInput = (const char *)sqlite3_value_text(argv[argc-1]); |
| 273 |
| 274 if( argc==3 ){ |
| 275 zArg = (const char *)sqlite3_value_text(argv[1]); |
| 276 } |
| 277 |
| 278 pHash = (Fts3Hash *)sqlite3_user_data(context); |
| 279 p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1); |
| 280 |
| 281 if( !p ){ |
| 282 char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName); |
| 283 sqlite3_result_error(context, zErr, -1); |
| 284 sqlite3_free(zErr); |
| 285 return; |
| 286 } |
| 287 |
| 288 pRet = Tcl_NewObj(); |
| 289 Tcl_IncrRefCount(pRet); |
| 290 |
| 291 if( SQLITE_OK!=p->xCreate(zArg ? 1 : 0, &zArg, &pTokenizer) ){ |
| 292 zErr = "error in xCreate()"; |
| 293 goto finish; |
| 294 } |
| 295 pTokenizer->pModule = p; |
| 296 if( SQLITE_OK!=p->xOpen(pTokenizer, zInput, nInput, &pCsr) ){ |
| 297 zErr = "error in xOpen()"; |
| 298 goto finish; |
| 299 } |
| 300 pCsr->pTokenizer = pTokenizer; |
| 301 |
| 302 while( SQLITE_OK==p->xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos) ){ |
| 303 Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(iPos)); |
| 304 Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken)); |
| 305 zToken = &zInput[iStart]; |
| 306 nToken = iEnd-iStart; |
| 307 Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken)); |
| 308 } |
| 309 |
| 310 if( SQLITE_OK!=p->xClose(pCsr) ){ |
| 311 zErr = "error in xClose()"; |
| 312 goto finish; |
| 313 } |
| 314 if( SQLITE_OK!=p->xDestroy(pTokenizer) ){ |
| 315 zErr = "error in xDestroy()"; |
| 316 goto finish; |
| 317 } |
| 318 |
| 319 finish: |
| 320 if( zErr ){ |
| 321 sqlite3_result_error(context, zErr, -1); |
| 322 }else{ |
| 323 sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT); |
| 324 } |
| 325 Tcl_DecrRefCount(pRet); |
| 326 } |
| 327 |
| 328 static |
| 329 int registerTokenizer( |
| 330 sqlite3 *db, |
| 331 char *zName, |
| 332 const sqlite3_tokenizer_module *p |
| 333 ){ |
| 334 int rc; |
| 335 sqlite3_stmt *pStmt; |
| 336 const char zSql[] = "SELECT fts3_tokenizer(?, ?)"; |
| 337 |
| 338 rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0); |
| 339 if( rc!=SQLITE_OK ){ |
| 340 return rc; |
| 341 } |
| 342 |
| 343 sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC); |
| 344 sqlite3_bind_blob(pStmt, 2, &p, sizeof(p), SQLITE_STATIC); |
| 345 sqlite3_step(pStmt); |
| 346 |
| 347 return sqlite3_finalize(pStmt); |
| 348 } |
| 349 |
| 350 static |
| 351 int queryTokenizer( |
| 352 sqlite3 *db, |
| 353 char *zName, |
| 354 const sqlite3_tokenizer_module **pp |
| 355 ){ |
| 356 int rc; |
| 357 sqlite3_stmt *pStmt; |
| 358 const char zSql[] = "SELECT fts3_tokenizer(?)"; |
| 359 |
| 360 *pp = 0; |
| 361 rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0); |
| 362 if( rc!=SQLITE_OK ){ |
| 363 return rc; |
| 364 } |
| 365 |
| 366 sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC); |
| 367 if( SQLITE_ROW==sqlite3_step(pStmt) ){ |
| 368 if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB ){ |
| 369 memcpy((void *)pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp)); |
| 370 } |
| 371 } |
| 372 |
| 373 return sqlite3_finalize(pStmt); |
| 374 } |
| 375 |
| 376 void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule); |
| 377 |
| 378 /* |
| 379 ** Implementation of the scalar function fts3_tokenizer_internal_test(). |
| 380 ** This function is used for testing only, it is not included in the |
| 381 ** build unless SQLITE_TEST is defined. |
| 382 ** |
| 383 ** The purpose of this is to test that the fts3_tokenizer() function |
| 384 ** can be used as designed by the C-code in the queryTokenizer and |
| 385 ** registerTokenizer() functions above. These two functions are repeated |
| 386 ** in the README.tokenizer file as an example, so it is important to |
| 387 ** test them. |
| 388 ** |
| 389 ** To run the tests, evaluate the fts3_tokenizer_internal_test() scalar |
| 390 ** function with no arguments. An assert() will fail if a problem is |
| 391 ** detected. i.e.: |
| 392 ** |
| 393 ** SELECT fts3_tokenizer_internal_test(); |
| 394 ** |
| 395 */ |
| 396 static void intTestFunc( |
| 397 sqlite3_context *context, |
| 398 int argc, |
| 399 sqlite3_value **argv |
| 400 ){ |
| 401 int rc; |
| 402 const sqlite3_tokenizer_module *p1; |
| 403 const sqlite3_tokenizer_module *p2; |
| 404 sqlite3 *db = (sqlite3 *)sqlite3_user_data(context); |
| 405 |
| 406 UNUSED_PARAMETER(argc); |
| 407 UNUSED_PARAMETER(argv); |
| 408 |
| 409 /* Test the query function */ |
| 410 sqlite3Fts3SimpleTokenizerModule(&p1); |
| 411 rc = queryTokenizer(db, "simple", &p2); |
| 412 assert( rc==SQLITE_OK ); |
| 413 assert( p1==p2 ); |
| 414 rc = queryTokenizer(db, "nosuchtokenizer", &p2); |
| 415 assert( rc==SQLITE_ERROR ); |
| 416 assert( p2==0 ); |
| 417 assert( 0==strcmp(sqlite3_errmsg(db), "unknown tokenizer: nosuchtokenizer") ); |
| 418 |
| 419 /* Test the storage function */ |
| 420 rc = registerTokenizer(db, "nosuchtokenizer", p1); |
| 421 assert( rc==SQLITE_OK ); |
| 422 rc = queryTokenizer(db, "nosuchtokenizer", &p2); |
| 423 assert( rc==SQLITE_OK ); |
| 424 assert( p2==p1 ); |
| 425 |
| 426 sqlite3_result_text(context, "ok", -1, SQLITE_STATIC); |
| 427 } |
| 428 |
| 429 #endif |
| 430 |
| 431 /* |
| 432 ** Set up SQL objects in database db used to access the contents of |
| 433 ** the hash table pointed to by argument pHash. The hash table must |
| 434 ** been initialised to use string keys, and to take a private copy |
| 435 ** of the key when a value is inserted. i.e. by a call similar to: |
| 436 ** |
| 437 ** sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1); |
| 438 ** |
| 439 ** This function adds a scalar function (see header comment above |
| 440 ** scalarFunc() in this file for details) and, if ENABLE_TABLE is |
| 441 ** defined at compilation time, a temporary virtual table (see header |
| 442 ** comment above struct HashTableVtab) to the database schema. Both |
| 443 ** provide read/write access to the contents of *pHash. |
| 444 ** |
| 445 ** The third argument to this function, zName, is used as the name |
| 446 ** of both the scalar and, if created, the virtual table. |
| 447 */ |
| 448 int sqlite3Fts3InitHashTable( |
| 449 sqlite3 *db, |
| 450 Fts3Hash *pHash, |
| 451 const char *zName |
| 452 ){ |
| 453 int rc = SQLITE_OK; |
| 454 void *p = (void *)pHash; |
| 455 const int any = SQLITE_ANY; |
| 456 |
| 457 #ifdef SQLITE_TEST |
| 458 char *zTest = 0; |
| 459 char *zTest2 = 0; |
| 460 void *pdb = (void *)db; |
| 461 zTest = sqlite3_mprintf("%s_test", zName); |
| 462 zTest2 = sqlite3_mprintf("%s_internal_test", zName); |
| 463 if( !zTest || !zTest2 ){ |
| 464 rc = SQLITE_NOMEM; |
| 465 } |
| 466 #endif |
| 467 |
| 468 if( SQLITE_OK==rc ){ |
| 469 rc = sqlite3_create_function(db, zName, 1, any, p, scalarFunc, 0, 0); |
| 470 } |
| 471 if( SQLITE_OK==rc ){ |
| 472 rc = sqlite3_create_function(db, zName, 2, any, p, scalarFunc, 0, 0); |
| 473 } |
| 474 #ifdef SQLITE_TEST |
| 475 if( SQLITE_OK==rc ){ |
| 476 rc = sqlite3_create_function(db, zTest, 2, any, p, testFunc, 0, 0); |
| 477 } |
| 478 if( SQLITE_OK==rc ){ |
| 479 rc = sqlite3_create_function(db, zTest, 3, any, p, testFunc, 0, 0); |
| 480 } |
| 481 if( SQLITE_OK==rc ){ |
| 482 rc = sqlite3_create_function(db, zTest2, 0, any, pdb, intTestFunc, 0, 0); |
| 483 } |
| 484 #endif |
| 485 |
| 486 #ifdef SQLITE_TEST |
| 487 sqlite3_free(zTest); |
| 488 sqlite3_free(zTest2); |
| 489 #endif |
| 490 |
| 491 return rc; |
| 492 } |
| 493 |
| 494 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */ |
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