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Diffstat (limited to '')
| -rw-r--r-- | ext/fts3/fts3_tokenizer.c | 520 |
1 files changed, 520 insertions, 0 deletions
diff --git a/ext/fts3/fts3_tokenizer.c b/ext/fts3/fts3_tokenizer.c new file mode 100644 index 0000000..eab3f51 --- /dev/null +++ b/ext/fts3/fts3_tokenizer.c @@ -0,0 +1,520 @@ +/* +** 2007 June 22 +** +** 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 is part of an SQLite module implementing full-text search. +** This particular file implements the generic tokenizer interface. +*/ + +/* +** The code in this file is only compiled if: +** +** * The FTS3 module is being built as an extension +** (in which case SQLITE_CORE is not defined), or +** +** * The FTS3 module is being built into the core of +** SQLite (in which case SQLITE_ENABLE_FTS3 is defined). +*/ +#include "fts3Int.h" +#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) + +#include <assert.h> +#include <string.h> + +/* +** Return true if the two-argument version of fts3_tokenizer() +** has been activated via a prior call to sqlite3_db_config(db, +** SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, 1, 0); +*/ +static int fts3TokenizerEnabled(sqlite3_context *context){ + sqlite3 *db = sqlite3_context_db_handle(context); + int isEnabled = 0; + sqlite3_db_config(db,SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER,-1,&isEnabled); + return isEnabled; +} + +/* +** Implementation of the SQL scalar function for accessing the underlying +** hash table. This function may be called as follows: +** +** SELECT <function-name>(<key-name>); +** SELECT <function-name>(<key-name>, <pointer>); +** +** where <function-name> is the name passed as the second argument +** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer'). +** +** If the <pointer> argument is specified, it must be a blob value +** containing a pointer to be stored as the hash data corresponding +** to the string <key-name>. If <pointer> is not specified, then +** the string <key-name> must already exist in the has table. Otherwise, +** an error is returned. +** +** Whether or not the <pointer> argument is specified, the value returned +** is a blob containing the pointer stored as the hash data corresponding +** to string <key-name> (after the hash-table is updated, if applicable). +*/ +static void fts3TokenizerFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + Fts3Hash *pHash; + void *pPtr = 0; + const unsigned char *zName; + int nName; + + assert( argc==1 || argc==2 ); + + pHash = (Fts3Hash *)sqlite3_user_data(context); + + zName = sqlite3_value_text(argv[0]); + nName = sqlite3_value_bytes(argv[0])+1; + + if( argc==2 ){ + if( fts3TokenizerEnabled(context) || sqlite3_value_frombind(argv[1]) ){ + void *pOld; + int n = sqlite3_value_bytes(argv[1]); + if( zName==0 || n!=sizeof(pPtr) ){ + sqlite3_result_error(context, "argument type mismatch", -1); + return; + } + pPtr = *(void **)sqlite3_value_blob(argv[1]); + pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr); + if( pOld==pPtr ){ + sqlite3_result_error(context, "out of memory", -1); + } + }else{ + sqlite3_result_error(context, "fts3tokenize disabled", -1); + return; + } + }else{ + if( zName ){ + pPtr = sqlite3Fts3HashFind(pHash, zName, nName); + } + if( !pPtr ){ + char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName); + sqlite3_result_error(context, zErr, -1); + sqlite3_free(zErr); + return; + } + } + if( fts3TokenizerEnabled(context) || sqlite3_value_frombind(argv[0]) ){ + sqlite3_result_blob(context, (void *)&pPtr, sizeof(pPtr), SQLITE_TRANSIENT); + } +} + +int sqlite3Fts3IsIdChar(char c){ + static const char isFtsIdChar[] = { + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 1x */ + 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 2x */ + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, /* 3x */ + 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 4x */ + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, /* 5x */ + 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6x */ + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, /* 7x */ + }; + return (c&0x80 || isFtsIdChar[(int)(c)]); +} + +const char *sqlite3Fts3NextToken(const char *zStr, int *pn){ + const char *z1; + const char *z2 = 0; + + /* Find the start of the next token. */ + z1 = zStr; + while( z2==0 ){ + char c = *z1; + switch( c ){ + case '\0': return 0; /* No more tokens here */ + case '\'': + case '"': + case '`': { + z2 = z1; + while( *++z2 && (*z2!=c || *++z2==c) ); + break; + } + case '[': + z2 = &z1[1]; + while( *z2 && z2[0]!=']' ) z2++; + if( *z2 ) z2++; + break; + + default: + if( sqlite3Fts3IsIdChar(*z1) ){ + z2 = &z1[1]; + while( sqlite3Fts3IsIdChar(*z2) ) z2++; + }else{ + z1++; + } + } + } + + *pn = (int)(z2-z1); + return z1; +} + +int sqlite3Fts3InitTokenizer( + Fts3Hash *pHash, /* Tokenizer hash table */ + const char *zArg, /* Tokenizer name */ + sqlite3_tokenizer **ppTok, /* OUT: Tokenizer (if applicable) */ + char **pzErr /* OUT: Set to malloced error message */ +){ + int rc; + char *z = (char *)zArg; + int n = 0; + char *zCopy; + char *zEnd; /* Pointer to nul-term of zCopy */ + sqlite3_tokenizer_module *m; + + zCopy = sqlite3_mprintf("%s", zArg); + if( !zCopy ) return SQLITE_NOMEM; + zEnd = &zCopy[strlen(zCopy)]; + + z = (char *)sqlite3Fts3NextToken(zCopy, &n); + if( z==0 ){ + assert( n==0 ); + z = zCopy; + } + z[n] = '\0'; + sqlite3Fts3Dequote(z); + + m = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash,z,(int)strlen(z)+1); + if( !m ){ + sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer: %s", z); + rc = SQLITE_ERROR; + }else{ + char const **aArg = 0; + int iArg = 0; + z = &z[n+1]; + while( z<zEnd && (NULL!=(z = (char *)sqlite3Fts3NextToken(z, &n))) ){ + sqlite3_int64 nNew = sizeof(char *)*(iArg+1); + char const **aNew = (const char **)sqlite3_realloc64((void *)aArg, nNew); + if( !aNew ){ + sqlite3_free(zCopy); + sqlite3_free((void *)aArg); + return SQLITE_NOMEM; + } + aArg = aNew; + aArg[iArg++] = z; + z[n] = '\0'; + sqlite3Fts3Dequote(z); + z = &z[n+1]; + } + rc = m->xCreate(iArg, aArg, ppTok); + assert( rc!=SQLITE_OK || *ppTok ); + if( rc!=SQLITE_OK ){ + sqlite3Fts3ErrMsg(pzErr, "unknown tokenizer"); + }else{ + (*ppTok)->pModule = m; + } + sqlite3_free((void *)aArg); + } + + sqlite3_free(zCopy); + return rc; +} + + +#ifdef SQLITE_TEST + +#if defined(INCLUDE_SQLITE_TCL_H) +# include "sqlite_tcl.h" +#else +# include "tcl.h" +#endif +#include <string.h> + +/* +** Implementation of a special SQL scalar function for testing tokenizers +** designed to be used in concert with the Tcl testing framework. This +** function must be called with two or more arguments: +** +** SELECT <function-name>(<key-name>, ..., <input-string>); +** +** where <function-name> is the name passed as the second argument +** to the sqlite3Fts3InitHashTable() function (e.g. 'fts3_tokenizer') +** concatenated with the string '_test' (e.g. 'fts3_tokenizer_test'). +** +** The return value is a string that may be interpreted as a Tcl +** list. For each token in the <input-string>, three elements are +** added to the returned list. The first is the token position, the +** second is the token text (folded, stemmed, etc.) and the third is the +** substring of <input-string> associated with the token. For example, +** using the built-in "simple" tokenizer: +** +** SELECT fts_tokenizer_test('simple', 'I don't see how'); +** +** will return the string: +** +** "{0 i I 1 dont don't 2 see see 3 how how}" +** +*/ +static void testFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + Fts3Hash *pHash; + sqlite3_tokenizer_module *p; + sqlite3_tokenizer *pTokenizer = 0; + sqlite3_tokenizer_cursor *pCsr = 0; + + const char *zErr = 0; + + const char *zName; + int nName; + const char *zInput; + int nInput; + + const char *azArg[64]; + + const char *zToken; + int nToken = 0; + int iStart = 0; + int iEnd = 0; + int iPos = 0; + int i; + + Tcl_Obj *pRet; + + if( argc<2 ){ + sqlite3_result_error(context, "insufficient arguments", -1); + return; + } + + nName = sqlite3_value_bytes(argv[0]); + zName = (const char *)sqlite3_value_text(argv[0]); + nInput = sqlite3_value_bytes(argv[argc-1]); + zInput = (const char *)sqlite3_value_text(argv[argc-1]); + + pHash = (Fts3Hash *)sqlite3_user_data(context); + p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1); + + if( !p ){ + char *zErr2 = sqlite3_mprintf("unknown tokenizer: %s", zName); + sqlite3_result_error(context, zErr2, -1); + sqlite3_free(zErr2); + return; + } + + pRet = Tcl_NewObj(); + Tcl_IncrRefCount(pRet); + + for(i=1; i<argc-1; i++){ + azArg[i-1] = (const char *)sqlite3_value_text(argv[i]); + } + + if( SQLITE_OK!=p->xCreate(argc-2, azArg, &pTokenizer) ){ + zErr = "error in xCreate()"; + goto finish; + } + pTokenizer->pModule = p; + if( sqlite3Fts3OpenTokenizer(pTokenizer, 0, zInput, nInput, &pCsr) ){ + zErr = "error in xOpen()"; + goto finish; + } + + while( SQLITE_OK==p->xNext(pCsr, &zToken, &nToken, &iStart, &iEnd, &iPos) ){ + Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(iPos)); + Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken)); + zToken = &zInput[iStart]; + nToken = iEnd-iStart; + Tcl_ListObjAppendElement(0, pRet, Tcl_NewStringObj(zToken, nToken)); + } + + if( SQLITE_OK!=p->xClose(pCsr) ){ + zErr = "error in xClose()"; + goto finish; + } + if( SQLITE_OK!=p->xDestroy(pTokenizer) ){ + zErr = "error in xDestroy()"; + goto finish; + } + +finish: + if( zErr ){ + sqlite3_result_error(context, zErr, -1); + }else{ + sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT); + } + Tcl_DecrRefCount(pRet); +} + +static +int registerTokenizer( + sqlite3 *db, + char *zName, + const sqlite3_tokenizer_module *p +){ + int rc; + sqlite3_stmt *pStmt; + const char zSql[] = "SELECT fts3_tokenizer(?, ?)"; + + rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0); + if( rc!=SQLITE_OK ){ + return rc; + } + + sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC); + sqlite3_bind_blob(pStmt, 2, &p, sizeof(p), SQLITE_STATIC); + sqlite3_step(pStmt); + + return sqlite3_finalize(pStmt); +} + + +static +int queryTokenizer( + sqlite3 *db, + char *zName, + const sqlite3_tokenizer_module **pp +){ + int rc; + sqlite3_stmt *pStmt; + const char zSql[] = "SELECT fts3_tokenizer(?)"; + + *pp = 0; + rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0); + if( rc!=SQLITE_OK ){ + return rc; + } + + sqlite3_bind_text(pStmt, 1, zName, -1, SQLITE_STATIC); + if( SQLITE_ROW==sqlite3_step(pStmt) ){ + if( sqlite3_column_type(pStmt, 0)==SQLITE_BLOB + && sqlite3_column_bytes(pStmt, 0)==sizeof(*pp) + ){ + memcpy((void *)pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp)); + } + } + + return sqlite3_finalize(pStmt); +} + +void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule); + +/* +** Implementation of the scalar function fts3_tokenizer_internal_test(). +** This function is used for testing only, it is not included in the +** build unless SQLITE_TEST is defined. +** +** The purpose of this is to test that the fts3_tokenizer() function +** can be used as designed by the C-code in the queryTokenizer and +** registerTokenizer() functions above. These two functions are repeated +** in the README.tokenizer file as an example, so it is important to +** test them. +** +** To run the tests, evaluate the fts3_tokenizer_internal_test() scalar +** function with no arguments. An assert() will fail if a problem is +** detected. i.e.: +** +** SELECT fts3_tokenizer_internal_test(); +** +*/ +static void intTestFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + int rc; + const sqlite3_tokenizer_module *p1; + const sqlite3_tokenizer_module *p2; + sqlite3 *db = (sqlite3 *)sqlite3_user_data(context); + + UNUSED_PARAMETER(argc); + UNUSED_PARAMETER(argv); + + /* Test the query function */ + sqlite3Fts3SimpleTokenizerModule(&p1); + rc = queryTokenizer(db, "simple", &p2); + assert( rc==SQLITE_OK ); + assert( p1==p2 ); + rc = queryTokenizer(db, "nosuchtokenizer", &p2); + assert( rc==SQLITE_ERROR ); + assert( p2==0 ); + assert( 0==strcmp(sqlite3_errmsg(db), "unknown tokenizer: nosuchtokenizer") ); + + /* Test the storage function */ + if( fts3TokenizerEnabled(context) ){ + rc = registerTokenizer(db, "nosuchtokenizer", p1); + assert( rc==SQLITE_OK ); + rc = queryTokenizer(db, "nosuchtokenizer", &p2); + assert( rc==SQLITE_OK ); + assert( p2==p1 ); + } + + sqlite3_result_text(context, "ok", -1, SQLITE_STATIC); +} + +#endif + +/* +** Set up SQL objects in database db used to access the contents of +** the hash table pointed to by argument pHash. The hash table must +** been initialized to use string keys, and to take a private copy +** of the key when a value is inserted. i.e. by a call similar to: +** +** sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1); +** +** This function adds a scalar function (see header comment above +** fts3TokenizerFunc() in this file for details) and, if ENABLE_TABLE is +** defined at compilation time, a temporary virtual table (see header +** comment above struct HashTableVtab) to the database schema. Both +** provide read/write access to the contents of *pHash. +** +** The third argument to this function, zName, is used as the name +** of both the scalar and, if created, the virtual table. +*/ +int sqlite3Fts3InitHashTable( + sqlite3 *db, + Fts3Hash *pHash, + const char *zName +){ + int rc = SQLITE_OK; + void *p = (void *)pHash; + const int any = SQLITE_UTF8|SQLITE_DIRECTONLY; + +#ifdef SQLITE_TEST + char *zTest = 0; + char *zTest2 = 0; + void *pdb = (void *)db; + zTest = sqlite3_mprintf("%s_test", zName); + zTest2 = sqlite3_mprintf("%s_internal_test", zName); + if( !zTest || !zTest2 ){ + rc = SQLITE_NOMEM; + } +#endif + + if( SQLITE_OK==rc ){ + rc = sqlite3_create_function(db, zName, 1, any, p, fts3TokenizerFunc, 0, 0); + } + if( SQLITE_OK==rc ){ + rc = sqlite3_create_function(db, zName, 2, any, p, fts3TokenizerFunc, 0, 0); + } +#ifdef SQLITE_TEST + if( SQLITE_OK==rc ){ + rc = sqlite3_create_function(db, zTest, -1, any, p, testFunc, 0, 0); + } + if( SQLITE_OK==rc ){ + rc = sqlite3_create_function(db, zTest2, 0, any, pdb, intTestFunc, 0, 0); + } +#endif + +#ifdef SQLITE_TEST + sqlite3_free(zTest); + sqlite3_free(zTest2); +#endif + + return rc; +} + +#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */ |