ogrsqlitedriver.cpp

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

/******************************************************************************
 * $Id: ogrsqlitedriver.cpp,v 1.3 2004/10/08 20:05:24 fwarmerdam Exp $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  Implements OGRSQLiteDriver class.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 2004, Frank Warmerdam <[e-mail]>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ******************************************************************************
 *
 * $Log: ogrsqlitedriver.cpp,v $
 * Revision 1.3  2004/10/08 20:05:24  fwarmerdam
 * Avoid leaking uninitialized OGRSQLiteDataSource.
 *
 * Revision 1.2  2004/07/12 20:50:46  warmerda
 * table/database creation now implemented
 *
 * Revision 1.1  2004/07/09 06:25:04  warmerda
 * New
 *
 */

#include "ogr_sqlite.h"
#include "cpl_conv.h"

CPL_CVSID("$Id: ogrsqlitedriver.cpp,v 1.3 2004/10/08 20:05:24 fwarmerdam Exp $");

/************************************************************************/
/*                            ~OGRSQLiteDriver()                            */
/************************************************************************/

OGRSQLiteDriver::~OGRSQLiteDriver()

{
}

/************************************************************************/
/*                              GetName()                               */
/************************************************************************/

const char *OGRSQLiteDriver::GetName()

{
    return "SQLite";
}

/************************************************************************/
/*                                Open()                                */
/************************************************************************/

OGRDataSource *OGRSQLiteDriver::Open( const char * pszFilename,
                                     int bUpdate )

{
/* -------------------------------------------------------------------- */
/*      Verify that the target is a real file, and has an               */
/*      appropriate magic string at the beginning.                      */
/* -------------------------------------------------------------------- */
    FILE *fpDB;
    char szHeader[16];
    
    fpDB = VSIFOpen( pszFilename, "rb" );
    if( fpDB == NULL )
        return NULL;
    
    if( VSIFRead( szHeader, 1, 16, fpDB ) != 16 )
        memset( szHeader, 0, 16 );
    
    VSIFClose( fpDB );
    
    if( strncmp( szHeader, "SQLite format 3", 15 ) != 0 )
        return NULL;

/* -------------------------------------------------------------------- */
/*      We think this is really an SQLite database, go ahead and try    */
/*      and open it.                                                    */
/* -------------------------------------------------------------------- */
    OGRSQLiteDataSource     *poDS;

    poDS = new OGRSQLiteDataSource();

    if( !poDS->Open( pszFilename ) )
    {
        delete poDS;
        return NULL;
    }
    else
        return poDS;
}

/************************************************************************/
/*                          CreateDataSource()                          */
/************************************************************************/

OGRDataSource *OGRSQLiteDriver::CreateDataSource( const char * pszName,
                                                  char ** /* papszOptions */ )

{
/* -------------------------------------------------------------------- */
/*      First, ensure there isn't any such file yet.                    */
/* -------------------------------------------------------------------- */
    VSIStatBuf sStatBuf;

    if( VSIStat( pszName, &sStatBuf ) == 0 )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "It seems a file system object called '%s' already exists.",
                  pszName );

        return NULL;
    }

/* -------------------------------------------------------------------- */
/*      Create the datasource.                                          */
/* -------------------------------------------------------------------- */
    OGRSQLiteDataSource     *poDS;

    poDS = new OGRSQLiteDataSource();

    if( !poDS->Open( pszName ) )
    {
        delete poDS;
        return NULL;
    }

    return poDS;
}

/************************************************************************/
/*                           TestCapability()                           */
/************************************************************************/

int OGRSQLiteDriver::TestCapability( const char * pszCap )

{
    if( EQUAL(pszCap,ODrCCreateDataSource) )
        return TRUE;
    else
        return FALSE;
}

/************************************************************************/
/*                         RegisterOGRSQLite()                          */
/************************************************************************/

void RegisterOGRSQLite()

{
    OGRSFDriverRegistrar::GetRegistrar()->RegisterDriver( new OGRSQLiteDriver );
}