engine/sqlite/src/vtab.cpp
changeset 97 3903521a36da
parent 96 87e863f6f840
child 98 5f9e7e14eb11
--- a/engine/sqlite/src/vtab.cpp	Wed May 26 10:44:32 2010 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,797 +0,0 @@
-/*
-** 2006 June 10
-**
-** 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 file contains code used to help implement virtual tables.
-**
-** $Id: vtab.cpp 1282 2008-11-13 09:31:33Z LarsPson $
-*/
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-#include "sqliteInt.h"
-
-static int createModule(
-  sqlite3 *db,                    /* Database in which module is registered */
-  const char *zName,              /* Name assigned to this module */
-  const sqlite3_module *pModule,  /* The definition of the module */
-  void *pAux,                     /* Context pointer for xCreate/xConnect */
-  void (*xDestroy)(void *)        /* Module destructor function */
-) {
-  int rc, nName;
-  Module *pMod;
-
-  sqlite3_mutex_enter(db->mutex);
-  nName = strlen(zName);
-  pMod = (Module *)sqlite3DbMallocRaw(db, sizeof(Module) + nName + 1);
-  if( pMod ){
-    char *zCopy = (char *)(&pMod[1]);
-    memcpy(zCopy, zName, nName+1);
-    pMod->zName = zCopy;
-    pMod->pModule = pModule;
-    pMod->pAux = pAux;
-    pMod->xDestroy = xDestroy;
-    pMod = (Module *)sqlite3HashInsert(&db->aModule, zCopy, nName, (void*)pMod);
-    if( pMod && pMod->xDestroy ){
-      pMod->xDestroy(pMod->pAux);
-    }
-    sqlite3_free(pMod);
-    sqlite3ResetInternalSchema(db, 0);
-  }
-  rc = sqlite3ApiExit(db, SQLITE_OK);
-  sqlite3_mutex_leave(db->mutex);
-  return rc;
-}
-
-
-/*
-** External API function used to create a new virtual-table module.
-*/
-EXPORT_C int sqlite3_create_module(
-  sqlite3 *db,                    /* Database in which module is registered */
-  const char *zName,              /* Name assigned to this module */
-  const sqlite3_module *pModule,  /* The definition of the module */
-  void *pAux                      /* Context pointer for xCreate/xConnect */
-){
-  return createModule(db, zName, pModule, pAux, 0);
-}
-
-/*
-** External API function used to create a new virtual-table module.
-*/
-EXPORT_C int sqlite3_create_module_v2(
-  sqlite3 *db,                    /* Database in which module is registered */
-  const char *zName,              /* Name assigned to this module */
-  const sqlite3_module *pModule,  /* The definition of the module */
-  void *pAux,                     /* Context pointer for xCreate/xConnect */
-  void (*xDestroy)(void *)        /* Module destructor function */
-){
-  return createModule(db, zName, pModule, pAux, xDestroy);
-}
-
-/*
-** Lock the virtual table so that it cannot be disconnected.
-** Locks nest.  Every lock should have a corresponding unlock.
-** If an unlock is omitted, resources leaks will occur.  
-**
-** If a disconnect is attempted while a virtual table is locked,
-** the disconnect is deferred until all locks have been removed.
-*/
-void sqlite3VtabLock(sqlite3_vtab *pVtab){
-  pVtab->nRef++;
-}
-
-/*
-** Unlock a virtual table.  When the last lock is removed,
-** disconnect the virtual table.
-*/
-void sqlite3VtabUnlock(sqlite3 *db, sqlite3_vtab *pVtab){
-  pVtab->nRef--;
-  assert(db);
-  assert(!sqlite3SafetyCheck(db));
-  if( pVtab->nRef==0 ){
-    if( db->magic==SQLITE_MAGIC_BUSY ){
-      sqlite3SafetyOff(db);
-      pVtab->pModule->xDisconnect(pVtab);
-      sqlite3SafetyOn(db);
-    } else {
-      pVtab->pModule->xDisconnect(pVtab);
-    }
-  }
-}
-
-/*
-** Clear any and all virtual-table information from the Table record.
-** This routine is called, for example, just before deleting the Table
-** record.
-*/
-void sqlite3VtabClear(Table *p){
-  sqlite3_vtab *pVtab = p->pVtab;
-  if( pVtab ){
-    assert( p->pMod && p->pMod->pModule );
-    sqlite3VtabUnlock(p->pSchema->db, pVtab);
-    p->pVtab = 0;
-  }
-  if( p->azModuleArg ){
-    int i;
-    for(i=0; i<p->nModuleArg; i++){
-      sqlite3_free(p->azModuleArg[i]);
-    }
-    sqlite3_free(p->azModuleArg);
-  }
-}
-
-/*
-** Add a new module argument to pTable->azModuleArg[].
-** The string is not copied - the pointer is stored.  The
-** string will be freed automatically when the table is
-** deleted.
-*/
-static void addModuleArgument(sqlite3 *db, Table *pTable, char *zArg){
-  int i = pTable->nModuleArg++;
-  int nBytes = sizeof(char *)*(1+pTable->nModuleArg);
-  char **azModuleArg;
-  azModuleArg = (char**)sqlite3DbRealloc(db, pTable->azModuleArg, nBytes);
-  if( azModuleArg==0 ){
-    int j;
-    for(j=0; j<i; j++){
-      sqlite3_free(pTable->azModuleArg[j]);
-    }
-    sqlite3_free(zArg);
-    sqlite3_free(pTable->azModuleArg);
-    pTable->nModuleArg = 0;
-  }else{
-    azModuleArg[i] = zArg;
-    azModuleArg[i+1] = 0;
-  }
-  pTable->azModuleArg = azModuleArg;
-}
-
-/*
-** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE
-** statement.  The module name has been parsed, but the optional list
-** of parameters that follow the module name are still pending.
-*/
-void sqlite3VtabBeginParse(
-  Parse *pParse,        /* Parsing context */
-  Token *pName1,        /* Name of new table, or database name */
-  Token *pName2,        /* Name of new table or NULL */
-  Token *pModuleName    /* Name of the module for the virtual table */
-){
-  int iDb;              /* The database the table is being created in */
-  Table *pTable;        /* The new virtual table */
-  sqlite3 *db;          /* Database connection */
-
-  if( pParse->db->flags & SQLITE_SharedCache ){
-    sqlite3ErrorMsg(pParse, "Cannot use virtual tables in shared-cache mode");
-    return;
-  }
-
-  sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, 0);
-  pTable = pParse->pNewTable;
-  if( pTable==0 || pParse->nErr ) return;
-  assert( 0==pTable->pIndex );
-
-  db = pParse->db;
-  iDb = sqlite3SchemaToIndex(db, pTable->pSchema);
-  assert( iDb>=0 );
-
-  pTable->isVirtual = 1;
-  pTable->nModuleArg = 0;
-  addModuleArgument(db, pTable, sqlite3NameFromToken(db, pModuleName));
-  addModuleArgument(db, pTable, sqlite3DbStrDup(db, db->aDb[iDb].zName));
-  addModuleArgument(db, pTable, sqlite3DbStrDup(db, pTable->zName));
-  pParse->sNameToken.n = pModuleName->z + pModuleName->n - pName1->z;
-
-#ifndef SQLITE_OMIT_AUTHORIZATION
-  /* Creating a virtual table invokes the authorization callback twice.
-  ** The first invocation, to obtain permission to INSERT a row into the
-  ** sqlite_master table, has already been made by sqlite3StartTable().
-  ** The second call, to obtain permission to create the table, is made now.
-  */
-  if( pTable->azModuleArg ){
-    sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, 
-            pTable->azModuleArg[0], pParse->db->aDb[iDb].zName);
-  }
-#endif
-}
-
-/*
-** This routine takes the module argument that has been accumulating
-** in pParse->zArg[] and appends it to the list of arguments on the
-** virtual table currently under construction in pParse->pTable.
-*/
-static void addArgumentToVtab(Parse *pParse){
-  if( pParse->sArg.z && pParse->pNewTable ){
-    const char *z = (const char*)pParse->sArg.z;
-    int n = pParse->sArg.n;
-    sqlite3 *db = pParse->db;
-    addModuleArgument(db, pParse->pNewTable, sqlite3DbStrNDup(db, z, n));
-  }
-}
-
-/*
-** The parser calls this routine after the CREATE VIRTUAL TABLE statement
-** has been completely parsed.
-*/
-void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
-  Table *pTab;        /* The table being constructed */
-  sqlite3 *db;        /* The database connection */
-  char *zModule;      /* The module name of the table: USING modulename */
-  Module *pMod = 0;
-
-  addArgumentToVtab(pParse);
-  pParse->sArg.z = 0;
-
-  /* Lookup the module name. */
-  pTab = pParse->pNewTable;
-  if( pTab==0 ) return;
-  db = pParse->db;
-  if( pTab->nModuleArg<1 ) return;
-  zModule = pTab->azModuleArg[0];
-  pMod = (Module *)sqlite3HashFind(&db->aModule, zModule, strlen(zModule));
-  pTab->pMod = pMod;
-  
-  /* If the CREATE VIRTUAL TABLE statement is being entered for the
-  ** first time (in other words if the virtual table is actually being
-  ** created now instead of just being read out of sqlite_master) then
-  ** do additional initialization work and store the statement text
-  ** in the sqlite_master table.
-  */
-  if( !db->init.busy ){
-    char *zStmt;
-    char *zWhere;
-    int iDb;
-    Vdbe *v;
-
-    /* Compute the complete text of the CREATE VIRTUAL TABLE statement */
-    if( pEnd ){
-      pParse->sNameToken.n = pEnd->z - pParse->sNameToken.z + pEnd->n;
-    }
-    zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken);
-
-    /* A slot for the record has already been allocated in the 
-    ** SQLITE_MASTER table.  We just need to update that slot with all
-    ** the information we've collected.  
-    **
-    ** The top of the stack is the rootpage allocated by sqlite3StartTable().
-    ** This value is always 0 and is ignored, a virtual table does not have a
-    ** rootpage. The next entry on the stack is the rowid of the record
-    ** in the sqlite_master table.
-    */
-    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
-    sqlite3NestedParse(pParse,
-      "UPDATE %Q.%s "
-         "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
-       "WHERE rowid=#1",
-      db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
-      pTab->zName,
-      pTab->zName,
-      zStmt
-    );
-    sqlite3_free(zStmt);
-    v = sqlite3GetVdbe(pParse);
-    sqlite3ChangeCookie(db, v, iDb);
-
-    sqlite3VdbeAddOp(v, OP_Expire, 0, 0);
-    zWhere = sqlite3MPrintf(db, "name='%q'", pTab->zName);
-    sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 1, zWhere, P3_DYNAMIC);
-    sqlite3VdbeOp3(v, OP_VCreate, iDb, 0, pTab->zName, strlen(pTab->zName) + 1);
-  }
-
-  /* If we are rereading the sqlite_master table create the in-memory
-  ** record of the table. If the module has already been registered,
-  ** also call the xConnect method here.
-  */
-  else {
-    Table *pOld;
-    Schema *pSchema = pTab->pSchema;
-    const char *zName = pTab->zName;
-    int nName = strlen(zName) + 1;
-    pOld = (Table*)sqlite3HashInsert(&pSchema->tblHash, zName, nName, pTab);
-    if( pOld ){
-      db->mallocFailed = 1;
-      assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */
-      return;
-    }
-    pSchema->db = pParse->db;
-    pParse->pNewTable = 0;
-  }
-}
-
-/*
-** The parser calls this routine when it sees the first token
-** of an argument to the module name in a CREATE VIRTUAL TABLE statement.
-*/
-void sqlite3VtabArgInit(Parse *pParse){
-  addArgumentToVtab(pParse);
-  pParse->sArg.z = 0;
-  pParse->sArg.n = 0;
-}
-
-/*
-** The parser calls this routine for each token after the first token
-** in an argument to the module name in a CREATE VIRTUAL TABLE statement.
-*/
-void sqlite3VtabArgExtend(Parse *pParse, Token *p){
-  Token *pArg = &pParse->sArg;
-  if( pArg->z==0 ){
-    pArg->z = p->z;
-    pArg->n = p->n;
-  }else{
-    assert(pArg->z < p->z);
-    pArg->n = (p->z + p->n - pArg->z);
-  }
-}
-
-/*
-** Invoke a virtual table constructor (either xCreate or xConnect). The
-** pointer to the function to invoke is passed as the fourth parameter
-** to this procedure.
-*/
-static int vtabCallConstructor(
-  sqlite3 *db, 
-  Table *pTab,
-  Module *pMod,
-  int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**),
-  char **pzErr
-){
-  int rc;
-  int rc2;
-  sqlite3_vtab *pVtab = 0;
-  const char *const*azArg = (const char *const*)pTab->azModuleArg;
-  int nArg = pTab->nModuleArg;
-  char *zErr = 0;
-  char *zModuleName = sqlite3MPrintf(db, "%s", pTab->zName);
-
-  if( !zModuleName ){
-    return SQLITE_NOMEM;
-  }
-
-  assert( !db->pVTab );
-  assert( xConstruct );
-
-  db->pVTab = pTab;
-  rc = sqlite3SafetyOff(db);
-  assert( rc==SQLITE_OK );
-  rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVtab, &zErr);
-  rc2 = sqlite3SafetyOn(db);
-  if( rc==SQLITE_OK && pVtab ){
-    pVtab->pModule = pMod->pModule;
-    pVtab->nRef = 1;
-    pTab->pVtab = pVtab;
-  }
-
-  if( SQLITE_OK!=rc ){
-    if( zErr==0 ){
-      *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName);
-    }else {
-      *pzErr = sqlite3MPrintf(db, "%s", zErr);
-      sqlite3_free(zErr);
-    }
-  }else if( db->pVTab ){
-    const char *zFormat = "vtable constructor did not declare schema: %s";
-    *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName);
-    rc = SQLITE_ERROR;
-  } 
-  if( rc==SQLITE_OK ){
-    rc = rc2;
-  }
-  db->pVTab = 0;
-  sqlite3_free(zModuleName);
-
-  /* If everything went according to plan, loop through the columns
-  ** of the table to see if any of them contain the token "hidden".
-  ** If so, set the Column.isHidden flag and remove the token from
-  ** the type string.
-  */
-  if( rc==SQLITE_OK ){
-    int iCol;
-    for(iCol=0; iCol<pTab->nCol; iCol++){
-      char *zType = pTab->aCol[iCol].zType;
-      int nType;
-      int i = 0;
-      if( !zType ) continue;
-      nType = strlen(zType);
-      if( sqlite3StrNICmp("hidden", zType, 6) || (zType[6] && zType[6]!=' ') ){
-        for(i=0; i<nType; i++){
-          if( (0==sqlite3StrNICmp(" hidden", &zType[i], 7))
-           && (zType[i+7]=='\0' || zType[i+7]==' ')
-          ){
-            i++;
-            break;
-          }
-        }
-      }
-      if( i<nType ){
-        int j;
-        int nDel = 6 + (zType[i+6] ? 1 : 0);
-        for(j=i; (j+nDel)<=nType; j++){
-          zType[j] = zType[j+nDel];
-        }
-        if( zType[i]=='\0' && i>0 ){
-          assert(zType[i-1]==' ');
-          zType[i-1] = '\0';
-        }
-        pTab->aCol[iCol].isHidden = 1;
-      }
-    }
-  }
-  return rc;
-}
-
-/*
-** This function is invoked by the parser to call the xConnect() method
-** of the virtual table pTab. If an error occurs, an error code is returned 
-** and an error left in pParse.
-**
-** This call is a no-op if table pTab is not a virtual table.
-*/
-int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
-  Module *pMod;
-  int rc = SQLITE_OK;
-
-  if( !pTab || !pTab->isVirtual || pTab->pVtab ){
-    return SQLITE_OK;
-  }
-
-  pMod = pTab->pMod;
-  if( !pMod ){
-    const char *zModule = pTab->azModuleArg[0];
-    sqlite3ErrorMsg(pParse, "no such module: %s", zModule);
-    rc = SQLITE_ERROR;
-  } else {
-    char *zErr = 0;
-    sqlite3 *db = pParse->db;
-    rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr);
-    if( rc!=SQLITE_OK ){
-      sqlite3ErrorMsg(pParse, "%s", zErr);
-    }
-    sqlite3_free(zErr);
-  }
-
-  return rc;
-}
-
-/*
-** Add the virtual table pVtab to the array sqlite3.aVTrans[].
-*/
-static int addToVTrans(sqlite3 *db, sqlite3_vtab *pVtab){
-  const int ARRAY_INCR = 5;
-
-  /* Grow the sqlite3.aVTrans array if required */
-  if( (db->nVTrans%ARRAY_INCR)==0 ){
-    sqlite3_vtab **aVTrans;
-    int nBytes = sizeof(sqlite3_vtab *) * (db->nVTrans + ARRAY_INCR);
-    aVTrans = (sqlite3_vtab**)sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes);
-    if( !aVTrans ){
-      return SQLITE_NOMEM;
-    }
-    memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR);
-    db->aVTrans = aVTrans;
-  }
-
-  /* Add pVtab to the end of sqlite3.aVTrans */
-  db->aVTrans[db->nVTrans++] = pVtab;
-  sqlite3VtabLock(pVtab);
-  return SQLITE_OK;
-}
-
-/*
-** This function is invoked by the vdbe to call the xCreate method
-** of the virtual table named zTab in database iDb. 
-**
-** If an error occurs, *pzErr is set to point an an English language
-** description of the error and an SQLITE_XXX error code is returned.
-** In this case the caller must call sqlite3_free() on *pzErr.
-*/
-int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
-  int rc = SQLITE_OK;
-  Table *pTab;
-  Module *pMod;
-  const char *zModule;
-
-  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
-  assert(pTab && pTab->isVirtual && !pTab->pVtab);
-  pMod = pTab->pMod;
-  zModule = pTab->azModuleArg[0];
-
-  /* If the module has been registered and includes a Create method, 
-  ** invoke it now. If the module has not been registered, return an 
-  ** error. Otherwise, do nothing.
-  */
-  if( !pMod ){
-    *pzErr = sqlite3MPrintf(db, "no such module: %s", zModule);
-    rc = SQLITE_ERROR;
-  }else{
-    rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr);
-  }
-
-  if( rc==SQLITE_OK && pTab->pVtab ){
-      rc = addToVTrans(db, pTab->pVtab);
-  }
-
-  return rc;
-}
-
-/*
-** This function is used to set the schema of a virtual table.  It is only
-** valid to call this function from within the xCreate() or xConnect() of a
-** virtual table module.
-*/
-EXPORT_C int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
-  Parse sParse;
-
-  int rc = SQLITE_OK;
-  Table *pTab;
-  char *zErr = 0;
-
-  sqlite3_mutex_enter(db->mutex);
-  pTab = db->pVTab;
-  if( !pTab ){
-    sqlite3Error(db, SQLITE_MISUSE, 0);
-    sqlite3_mutex_leave(db->mutex);
-    return SQLITE_MISUSE;
-  }
-  assert(pTab->isVirtual && pTab->nCol==0 && pTab->aCol==0);
-
-  memset(&sParse, 0, sizeof(Parse));
-  sParse.declareVtab = 1;
-  sParse.db = db;
-
-  if( 
-      SQLITE_OK == sqlite3RunParser(&sParse, zCreateTable, &zErr) && 
-      sParse.pNewTable && 
-      !sParse.pNewTable->pSelect && 
-      !sParse.pNewTable->isVirtual 
-  ){
-    pTab->aCol = sParse.pNewTable->aCol;
-    pTab->nCol = sParse.pNewTable->nCol;
-    sParse.pNewTable->nCol = 0;
-    sParse.pNewTable->aCol = 0;
-    db->pVTab = 0;
-  } else {
-    sqlite3Error(db, SQLITE_ERROR, zErr);
-    sqlite3_free(zErr);
-    rc = SQLITE_ERROR;
-  }
-  sParse.declareVtab = 0;
-
-  sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
-  sqlite3DeleteTable(sParse.pNewTable);
-  sParse.pNewTable = 0;
-
-  assert( (rc&0xff)==rc );
-  rc = sqlite3ApiExit(db, rc);
-  sqlite3_mutex_leave(db->mutex);
-  return rc;
-}
-
-/*
-** This function is invoked by the vdbe to call the xDestroy method
-** of the virtual table named zTab in database iDb. This occurs
-** when a DROP TABLE is mentioned.
-**
-** This call is a no-op if zTab is not a virtual table.
-*/
-int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab)
-{
-  int rc = SQLITE_OK;
-  Table *pTab;
-
-  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
-  assert(pTab);
-  if( pTab->pVtab ){
-    int (*xDestroy)(sqlite3_vtab *pVTab) = pTab->pMod->pModule->xDestroy;
-    rc = sqlite3SafetyOff(db);
-    assert( rc==SQLITE_OK );
-    if( xDestroy ){
-      rc = xDestroy(pTab->pVtab);
-    }
-    sqlite3SafetyOn(db);
-    if( rc==SQLITE_OK ){
-      pTab->pVtab = 0;
-    }
-  }
-
-  return rc;
-}
-
-/*
-** This function invokes either the xRollback or xCommit method
-** of each of the virtual tables in the sqlite3.aVTrans array. The method
-** called is identified by the second argument, "offset", which is
-** the offset of the method to call in the sqlite3_module structure.
-**
-** The array is cleared after invoking the callbacks. 
-*/
-static void callFinaliser(sqlite3 *db, int offset){
-  int i;
-  if( db->aVTrans ){
-    for(i=0; i<db->nVTrans && db->aVTrans[i]; i++){
-      sqlite3_vtab *pVtab = db->aVTrans[i];
-      int (*x)(sqlite3_vtab *);
-      x = *(int (**)(sqlite3_vtab *))((char *)pVtab->pModule + offset);
-      if( x ) x(pVtab);
-      sqlite3VtabUnlock(db, pVtab);
-    }
-    sqlite3_free(db->aVTrans);
-    db->nVTrans = 0;
-    db->aVTrans = 0;
-  }
-}
-
-/*
-** If argument rc2 is not SQLITE_OK, then return it and do nothing. 
-** Otherwise, invoke the xSync method of all virtual tables in the 
-** sqlite3.aVTrans array. Return the error code for the first error 
-** that occurs, or SQLITE_OK if all xSync operations are successful.
-*/
-int sqlite3VtabSync(sqlite3 *db, int rc2){
-  int i;
-  int rc = SQLITE_OK;
-  int rcsafety;
-  sqlite3_vtab **aVTrans = db->aVTrans;
-  if( rc2!=SQLITE_OK ) return rc2;
-
-  rc = sqlite3SafetyOff(db);
-  db->aVTrans = 0;
-  for(i=0; rc==SQLITE_OK && i<db->nVTrans && aVTrans[i]; i++){
-    sqlite3_vtab *pVtab = aVTrans[i];
-    int (*x)(sqlite3_vtab *);
-    x = pVtab->pModule->xSync;
-    if( x ){
-      rc = x(pVtab);
-    }
-  }
-  db->aVTrans = aVTrans;
-  rcsafety = sqlite3SafetyOn(db);
-
-  if( rc==SQLITE_OK ){
-    rc = rcsafety;
-  }
-  return rc;
-}
-
-/*
-** Invoke the xRollback method of all virtual tables in the 
-** sqlite3.aVTrans array. Then clear the array itself.
-*/
-int sqlite3VtabRollback(sqlite3 *db){
-  callFinaliser(db, (int)(&((sqlite3_module *)0)->xRollback));
-  return SQLITE_OK;
-}
-
-/*
-** Invoke the xCommit method of all virtual tables in the 
-** sqlite3.aVTrans array. Then clear the array itself.
-*/
-int sqlite3VtabCommit(sqlite3 *db){
-  callFinaliser(db, (int)(&((sqlite3_module *)0)->xCommit));
-  return SQLITE_OK;
-}
-
-/*
-** If the virtual table pVtab supports the transaction interface
-** (xBegin/xRollback/xCommit and optionally xSync) and a transaction is
-** not currently open, invoke the xBegin method now.
-**
-** If the xBegin call is successful, place the sqlite3_vtab pointer
-** in the sqlite3.aVTrans array.
-*/
-int sqlite3VtabBegin(sqlite3 *db, sqlite3_vtab *pVtab){
-  int rc = SQLITE_OK;
-  const sqlite3_module *pModule;
-
-  /* Special case: If db->aVTrans is NULL and db->nVTrans is greater
-  ** than zero, then this function is being called from within a
-  ** virtual module xSync() callback. It is illegal to write to 
-  ** virtual module tables in this case, so return SQLITE_LOCKED.
-  */
-  if( 0==db->aVTrans && db->nVTrans>0 ){
-    return SQLITE_LOCKED;
-  }
-  if( !pVtab ){
-    return SQLITE_OK;
-  } 
-  pModule = pVtab->pModule;
-
-  if( pModule->xBegin ){
-    int i;
-
-
-    /* If pVtab is already in the aVTrans array, return early */
-    for(i=0; (i<db->nVTrans) && 0!=db->aVTrans[i]; i++){
-      if( db->aVTrans[i]==pVtab ){
-        return SQLITE_OK;
-      }
-    }
-
-    /* Invoke the xBegin method */
-    rc = pModule->xBegin(pVtab);
-    if( rc!=SQLITE_OK ){
-      return rc;
-    }
-
-    rc = addToVTrans(db, pVtab);
-  }
-  return rc;
-}
-
-/*
-** The first parameter (pDef) is a function implementation.  The
-** second parameter (pExpr) is the first argument to this function.
-** If pExpr is a column in a virtual table, then let the virtual
-** table implementation have an opportunity to overload the function.
-**
-** This routine is used to allow virtual table implementations to
-** overload MATCH, LIKE, GLOB, and REGEXP operators.
-**
-** Return either the pDef argument (indicating no change) or a 
-** new FuncDef structure that is marked as ephemeral using the
-** SQLITE_FUNC_EPHEM flag.
-*/
-FuncDef *sqlite3VtabOverloadFunction(
-  sqlite3 *db,    /* Database connection for reporting malloc problems */
-  FuncDef *pDef,  /* Function to possibly overload */
-  int nArg,       /* Number of arguments to the function */
-  Expr *pExpr     /* First argument to the function */
-){
-  Table *pTab;
-  sqlite3_vtab *pVtab;
-  sqlite3_module *pMod;
-  void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
-  void *pArg;
-  FuncDef *pNew;
-  int rc = 0;
-  char *zLowerName;
-  unsigned char *z;
-
-
-  /* Check to see the left operand is a column in a virtual table */
-  if( pExpr==0 ) return pDef;
-  if( pExpr->op!=TK_COLUMN ) return pDef;
-  pTab = pExpr->pTab;
-  if( pTab==0 ) return pDef;
-  if( !pTab->isVirtual ) return pDef;
-  pVtab = pTab->pVtab;
-  assert( pVtab!=0 );
-  assert( pVtab->pModule!=0 );
-  pMod = (sqlite3_module *)pVtab->pModule;
-  if( pMod->xFindFunction==0 ) return pDef;
- 
-  /* Call the xFindFunction method on the virtual table implementation
-  ** to see if the implementation wants to overload this function 
-  */
-  zLowerName = sqlite3DbStrDup(db, pDef->zName);
-  if( zLowerName ){
-    for(z=(unsigned char*)zLowerName; *z; z++){
-      *z = sqlite3UpperToLower[*z];
-    }
-    rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xFunc, &pArg);
-    sqlite3_free(zLowerName);
-  }
-  if( rc==0 ){
-    return pDef;
-  }
-
-  /* Create a new ephemeral function definition for the overloaded
-  ** function */
-  pNew = (FuncDef*)sqlite3DbMallocZero(db, sizeof(*pNew) + strlen(pDef->zName) );
-  if( pNew==0 ){
-    return pDef;
-  }
-  *pNew = *pDef;
-  memcpy(pNew->zName, pDef->zName, strlen(pDef->zName)+1);
-  pNew->xFunc = xFunc;
-  pNew->pUserData = pArg;
-  pNew->flags |= SQLITE_FUNC_EPHEM;
-  return pNew;
-}
-
-#endif /* SQLITE_OMIT_VIRTUALTABLE */