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) */ 495