[sql] Import reference version of SQLite 3.17..

third_party/sqlite/sqlite-src-3170000/ext/fts2/fts2_tokenizer.c

+/*
+** 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 FTS2 module is being built as an extension
+**       (in which case SQLITE_CORE is not defined), or
+**
+**     * The FTS2 module is being built into the core of
+**       SQLite (in which case SQLITE_ENABLE_FTS2 is defined).
+*/
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS2)
+
+
+#include "sqlite3.h"
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT3
+
+#include "fts2_hash.h"
+#include "fts2_tokenizer.h"
+#include <assert.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 sqlite3Fts2InitHashTable() function (e.g. 'fts2_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
+){
+  fts2Hash *pHash;
+  void *pPtr = 0;
+  const unsigned char *zName;
+  int nName;
+
+  assert( argc==1 || argc==2 );
+
+  pHash = (fts2Hash *)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 = sqlite3Fts2HashInsert(pHash, (void *)zName, nName, pPtr);
+    if( pOld==pPtr ){
+      sqlite3_result_error(context, "out of memory", -1);
+      return;
+    }
+  }else{
+    pPtr = sqlite3Fts2HashFind(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);
+}
+
+#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 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 sqlite3Fts2InitHashTable() function (e.g. 'fts2_tokenizer')
+** concatenated with the string '_test' (e.g. 'fts2_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
+){
+  fts2Hash *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 = (fts2Hash *)sqlite3_user_data(context);
+  p = (sqlite3_tokenizer_module *)sqlite3Fts2HashFind(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 fts2_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 queryFts2Tokenizer(
+  sqlite3 *db, 
+  char *zName,  
+  const sqlite3_tokenizer_module **pp
+){
+  int rc;
+  sqlite3_stmt *pStmt;
+  const char zSql[] = "SELECT fts2_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(pp, sqlite3_column_blob(pStmt, 0), sizeof(*pp));
+    }
+  }
+
+  return sqlite3_finalize(pStmt);
+}
+
+void sqlite3Fts2SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+
+/*
+** Implementation of the scalar function fts2_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 fts2_tokenizer() function
+** can be used as designed by the C-code in the queryFts2Tokenizer 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 fts2_tokenizer_internal_test() scalar
+** function with no arguments. An assert() will fail if a problem is
+** detected. i.e.:
+**
+**     SELECT fts2_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);
+
+  /* Test the query function */
+  sqlite3Fts2SimpleTokenizerModule(&p1);
+  rc = queryFts2Tokenizer(db, "simple", &p2);
+  assert( rc==SQLITE_OK );
+  assert( p1==p2 );
+  rc = queryFts2Tokenizer(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 = queryFts2Tokenizer(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:
+**
+**    sqlite3Fts2HashInit(pHash, FTS2_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 sqlite3Fts2InitHashTable(
+  sqlite3 *db, 
+  fts2Hash *pHash, 
+  const char *zName
+){
+  int rc = SQLITE_OK;
+  void *p = (void *)pHash;
+  const int any = SQLITE_ANY;
+  char *zTest = 0;
+  char *zTest2 = 0;
+
+#ifdef SQLITE_TEST
+  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( rc!=SQLITE_OK
+   || (rc = sqlite3_create_function(db, zName, 1, any, p, scalarFunc, 0, 0))
+   || (rc = sqlite3_create_function(db, zName, 2, any, p, scalarFunc, 0, 0))
+#ifdef SQLITE_TEST
+   || (rc = sqlite3_create_function(db, zTest, 2, any, p, testFunc, 0, 0))
+   || (rc = sqlite3_create_function(db, zTest, 3, any, p, testFunc, 0, 0))
+   || (rc = sqlite3_create_function(db, zTest2, 0, any, pdb, intTestFunc, 0, 0))
+#endif
+  );
+
+  sqlite3_free(zTest);
+  sqlite3_free(zTest2);
+  return rc;
+}
+
+#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS2) */