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authorHans-Christoph Steiner <hans@eds.org>2012-03-30 20:42:12 -0400
committerHans-Christoph Steiner <hans@eds.org>2012-03-30 20:42:12 -0400
commit7bb481fda9ecb134804b49c2ce77ca28f7eea583 (patch)
tree31b520b9914d3e2453968abe375f2c102772c3dc /ext/fts3/fts3_tokenizer.c
Imported Upstream version 2.0.3
Diffstat (limited to 'ext/fts3/fts3_tokenizer.c')
-rw-r--r--ext/fts3/fts3_tokenizer.c489
1 files changed, 489 insertions, 0 deletions
diff --git a/ext/fts3/fts3_tokenizer.c b/ext/fts3/fts3_tokenizer.c
new file mode 100644
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+++ b/ext/fts3/fts3_tokenizer.c
@@ -0,0 +1,489 @@
+/*
+** 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>
+
+/*
+** 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 scalarFunc(
+ 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 ){
+ void *pOld;
+ int n = sqlite3_value_bytes(argv[1]);
+ if( 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);
+ return;
+ }
+ }else{
+ 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;
+ }
+ }
+
+ 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);
+ z[n] = '\0';
+ sqlite3Fts3Dequote(z);
+
+ m = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash,z,(int)strlen(z)+1);
+ if( !m ){
+ *pzErr = sqlite3_mprintf("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))) ){
+ int nNew = sizeof(char *)*(iArg+1);
+ char const **aNew = (const char **)sqlite3_realloc((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 ){
+ *pzErr = sqlite3_mprintf("unknown tokenizer");
+ }else{
+ (*ppTok)->pModule = m;
+ }
+ sqlite3_free((void *)aArg);
+ }
+
+ sqlite3_free(zCopy);
+ return rc;
+}
+
+
+#ifdef SQLITE_TEST
+
+#include <tcl.h>
+#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 arguments:
+**
+** SELECT <function-name>(<key-name>, <input-string>);
+** 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')
+** 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 *zArg = 0;
+
+ const char *zToken;
+ int nToken;
+ int iStart;
+ int iEnd;
+ int iPos;
+
+ Tcl_Obj *pRet;
+
+ assert( argc==2 || argc==3 );
+
+ 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]);
+
+ if( argc==3 ){
+ zArg = (const char *)sqlite3_value_text(argv[1]);
+ }
+
+ pHash = (Fts3Hash *)sqlite3_user_data(context);
+ p = (sqlite3_tokenizer_module *)sqlite3Fts3HashFind(pHash, zName, nName+1);
+
+ if( !p ){
+ char *zErr = sqlite3_mprintf("unknown tokenizer: %s", zName);
+ sqlite3_result_error(context, zErr, -1);
+ sqlite3_free(zErr);
+ return;
+ }
+
+ pRet = Tcl_NewObj();
+ Tcl_IncrRefCount(pRet);
+
+ if( SQLITE_OK!=p->xCreate(zArg ? 1 : 0, &zArg, &pTokenizer) ){
+ zErr = "error in xCreate()";
+ goto finish;
+ }
+ pTokenizer->pModule = p;
+ if( SQLITE_OK!=p->xOpen(pTokenizer, zInput, nInput, &pCsr) ){
+ zErr = "error in xOpen()";
+ goto finish;
+ }
+ pCsr->pTokenizer = pTokenizer;
+
+ 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 ){
+ 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 */
+ 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 initialised 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
+** scalarFunc() 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_ANY;
+
+#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, scalarFunc, 0, 0);
+ }
+ if( SQLITE_OK==rc ){
+ rc = sqlite3_create_function(db, zName, 2, any, p, scalarFunc, 0, 0);
+ }
+#ifdef SQLITE_TEST
+ if( SQLITE_OK==rc ){
+ rc = sqlite3_create_function(db, zTest, 2, any, p, testFunc, 0, 0);
+ }
+ if( SQLITE_OK==rc ){
+ rc = sqlite3_create_function(db, zTest, 3, 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) */