4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
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.
11 ******************************************************************************
13 ** This is part of an SQLite module implementing full-text search.
14 ** This particular file implements the generic tokenizer interface.
18 ** The code in this file is only compiled if:
20 ** * The FTS3 module is being built as an extension
21 ** (in which case SQLITE_CORE is not defined), or
23 ** * The FTS3 module is being built into the core of
24 ** SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
26 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
28 #include "sqlite3ext.h"
30 SQLITE_EXTENSION_INIT1
38 ** Implementation of the SQL scalar function for accessing the underlying
39 ** hash table. This function may be called as follows:
41 ** SELECT <function-name>(<key-name>);
42 ** SELECT <function-name>(<key-name>, <pointer>);
44 ** where <function-name> is the name passed as the second argument
45 ** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer').
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.
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).
57 static void scalarFunc(
58 sqlite3_context *context,
64 const unsigned char *zName;
67 assert( argc==1 || argc==2 );
69 pHash = (Fts3Hash *)sqlite3_user_data(context);
71 zName = sqlite3_value_text(argv[0]);
72 nName = sqlite3_value_bytes(argv[0])+1;
76 int n = sqlite3_value_bytes(argv[1]);
77 if( n!=sizeof(pPtr) ){
78 sqlite3_result_error(context, "argument type mismatch", -1);
81 pPtr = *(void **)sqlite3_value_blob(argv[1]);
82 pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr);
84 sqlite3_result_error(context, "out of memory", -1);
88 pPtr = sqlite3Fts3HashFind(pHash, zName, nName);
90 char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName);
91 sqlite3_result_error(context, zErr, -1);
97 sqlite3_result_blob(context, (void *)&pPtr, sizeof(pPtr), SQLITE_TRANSIENT);
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 */
111 return (c&0x80 || isFtsIdChar[(int)(c)]);
114 const char *sqlite3Fts3NextToken(const char *zStr, int *pn){
118 /* Find the start of the next token. */
123 case '\0': return 0; /* No more tokens here */
128 while( *++z2 && (*z2!=c || *++z2==c) );
133 while( *z2 && z2[0]!=']' ) z2++;
138 if( sqlite3Fts3IsIdChar(*z1) ){
140 while( sqlite3Fts3IsIdChar(*z2) ) z2++;
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 */
158 char *z = (char *)zArg;
161 char *zEnd; /* Pointer to nul-term of zCopy */
162 sqlite3_tokenizer_module *m;
164 zCopy = sqlite3_mprintf("%s", zArg);
165 if( !zCopy ) return SQLITE_NOMEM;
166 zEnd = &zCopy[strlen(zCopy)];
168 z = (char *)sqlite3Fts3NextToken(zCopy, &n);
170 sqlite3Fts3Dequote(z);
172 m = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash,z,(int)strlen(z)+1);
174 *pzErr = sqlite3_mprintf("unknown tokenizer: %s", z);
177 char const **aArg = 0;
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);
185 sqlite3_free((void *)aArg);
191 sqlite3Fts3Dequote(z);
194 rc = m->xCreate(iArg, aArg, ppTok);
195 assert( rc!=SQLITE_OK || *ppTok );
197 *pzErr = sqlite3_mprintf("unknown tokenizer");
199 (*ppTok)->pModule = m;
201 sqlite3_free((void *)aArg);
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:
219 ** SELECT <function-name>(<key-name>, <input-string>);
220 ** SELECT <function-name>(<key-name>, <pointer>);
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').
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:
233 ** SELECT fts_tokenizer_test('simple', 'I don't see how');
235 ** will return the string:
237 ** "{0 i I 1 dont don't 2 see see 3 how how}"
240 static void testFunc(
241 sqlite3_context *context,
246 sqlite3_tokenizer_module *p;
247 sqlite3_tokenizer *pTokenizer = 0;
248 sqlite3_tokenizer_cursor *pCsr = 0;
250 const char *zErr = 0;
257 const char *zArg = 0;
267 assert( argc==2 || argc==3 );
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]);
275 zArg = (const char *)sqlite3_value_text(argv[1]);
278 pHash = (Fts3Hash *)sqlite3_user_data(context);
279 p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1);
282 char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName);
283 sqlite3_result_error(context, zErr, -1);
289 Tcl_IncrRefCount(pRet);
291 if( SQLITE_OK!=p->xCreate(zArg ? 1 : 0, &zArg, &pTokenizer) ){
292 zErr = "error in xCreate()";
295 pTokenizer->pModule = p;
296 if( SQLITE_OK!=p->xOpen(pTokenizer, zInput, nInput, &pCsr) ){
297 zErr = "error in xOpen()";
300 pCsr->pTokenizer = pTokenizer;
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));
310 if( SQLITE_OK!=p->xClose(pCsr) ){
311 zErr = "error in xClose()";
314 if( SQLITE_OK!=p->xDestroy(pTokenizer) ){
315 zErr = "error in xDestroy()";
321 sqlite3_result_error(context, zErr, -1);
323 sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT);
325 Tcl_DecrRefCount(pRet);
329 int registerTokenizer(
332 const sqlite3_tokenizer_module *p
336 const char zSql[] = "SELECT fts3_tokenizer(?, ?)";
338 rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
343 sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC);
344 sqlite3_bind_blob(pStmt, 2, &p, sizeof(p), SQLITE_STATIC);
347 return sqlite3_finalize(pStmt);
354 const sqlite3_tokenizer_module **pp
358 const char zSql[] = "SELECT fts3_tokenizer(?)";
361 rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
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));
373 return sqlite3_finalize(pStmt);
376 void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);
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.
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
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
393 ** SELECT fts3_tokenizer_internal_test();
396 static void intTestFunc(
397 sqlite3_context *context,
402 const sqlite3_tokenizer_module *p1;
403 const sqlite3_tokenizer_module *p2;
404 sqlite3 *db = (sqlite3 *)sqlite3_user_data(context);
406 UNUSED_PARAMETER(argc);
407 UNUSED_PARAMETER(argv);
409 /* Test the query function */
410 sqlite3Fts3SimpleTokenizerModule(&p1);
411 rc = queryTokenizer(db, "simple", &p2);
412 assert( rc==SQLITE_OK );
414 rc = queryTokenizer(db, "nosuchtokenizer", &p2);
415 assert( rc==SQLITE_ERROR );
417 assert( 0==strcmp(sqlite3_errmsg(db), "unknown tokenizer: nosuchtokenizer") );
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 );
426 sqlite3_result_text(context, "ok", -1, SQLITE_STATIC);
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:
437 ** sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);
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.
445 ** The third argument to this function, zName, is used as the name
446 ** of both the scalar and, if created, the virtual table.
448 int sqlite3Fts3InitHashTable(
454 void *p = (void *)pHash;
455 const int any = SQLITE_ANY;
460 void *pdb = (void *)db;
461 zTest = sqlite3_mprintf("%s_test", zName);
462 zTest2 = sqlite3_mprintf("%s_internal_test", zName);
463 if( !zTest || !zTest2 ){
469 rc = sqlite3_create_function(db, zName, 1, any, p, scalarFunc, 0, 0);
472 rc = sqlite3_create_function(db, zName, 2, any, p, scalarFunc, 0, 0);
476 rc = sqlite3_create_function(db, zTest, 2, any, p, testFunc, 0, 0);
479 rc = sqlite3_create_function(db, zTest, 3, any, p, testFunc, 0, 0);
482 rc = sqlite3_create_function(db, zTest2, 0, any, pdb, intTestFunc, 0, 0);
488 sqlite3_free(zTest2);
494 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */