SQLite

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test8.c,v 1.56 2007/09/03 11:51:50 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

  sqlite3_free(p->zThis);
  sqlite3_free(p->zTableName);
  sqlite3_free(p->zLogName);
  sqlite3_free(p);
  return 0;
}

typedef struct EchoModule EchoModule;
struct EchoModule {
  Tcl_Interp *interp;
};

/*
** This function is called to do the work of the xConnect() method -
** to allocate the required in-memory structures for a newly connected
** virtual table.
*/
static int echoConstructor(
  sqlite3 *db,

  echo_vtab *pVtab;

  /* Allocate the sqlite3_vtab/echo_vtab structure itself */
  pVtab = sqlite3MallocZero( sizeof(*pVtab) );
  if( !pVtab ){
    return SQLITE_NOMEM;
  }
  pVtab->interp = ((EchoModule *)pAux)->interp;
  pVtab->db = db;

  /* Allocate echo_vtab.zThis */
  pVtab->zThis = sqlite3MPrintf(0, "%s", argv[2]);
  if( !pVtab->zThis ){
    echoDestructor((sqlite3_vtab *)pVtab);
    return SQLITE_NOMEM;

  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  int rc = SQLITE_OK;
  appendToEchoModule(((EchoModule *)pAux)->interp, "xCreate");
  rc = echoConstructor(db, pAux, argc, argv, ppVtab, pzErr);

  /* If there were two arguments passed to the module at the SQL level 
  ** (i.e. "CREATE VIRTUAL TABLE tbl USING echo(arg1, arg2)"), then 
  ** the second argument is used as a table name. Attempt to create
  ** such a table with a single column, "logmsg". This table will
  ** be used to log calls to the xUpdate method. It will be deleted

static int echoConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  appendToEchoModule(((EchoModule *)pAux)->interp, "xConnect");
  return echoConstructor(db, pAux, argc, argv, ppVtab, pzErr);
}

/* 
** Echo virtual table module xDisconnect method.
*/
static int echoDisconnect(sqlite3_vtab *pVtab){

/*
** Decode a pointer to an sqlite3 object.
*/
static int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb){
  *ppDb = (sqlite3*)sqlite3TextToPtr(zA);
  return TCL_OK;
}

static void moduleDestroy(void *p){
  sqlite3_free(p);
}

/*
** Register the echo virtual table module.
*/
static int register_echo_module(
  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3 *db;
  EchoModule *pMod;
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  pMod = sqlite3_malloc(sizeof(EchoModule));
  pMod->interp = interp;
  sqlite3_create_module_v2(db, "echo", &echoModule, (void*)pMod, moduleDestroy);
  return TCL_OK;
}

/*
** Tcl interface to sqlite3_declare_vtab, invoked as follows from Tcl:
**
** sqlite3_declare_vtab DB SQL