ogrsfdriverregistrar.cpp

在linux环境下

    poDS = Open( pszName, bUpdate, &poTempDriver );

    if( poDS == NULL )
        return poDS;

/* -------------------------------------------------------------------- */
/*      We don't have this datasource already.  Grow our list to        */
/*      hold the new datasource.                                        */
/* -------------------------------------------------------------------- */
    papszOpenDSRawName = (char **) 
        CPLRealloc( papszOpenDSRawName, sizeof(char*) * (nOpenDSCount+1) );
    
    papoOpenDS = (OGRDataSource **) 
        CPLRealloc( papoOpenDS, sizeof(char*) * (nOpenDSCount+1) );
    
    papoOpenDSDriver = (OGRSFDriver **) 
        CPLRealloc( papoOpenDSDriver, sizeof(char*) * (nOpenDSCount+1) );

    papszOpenDSRawName[nOpenDSCount] = CPLStrdup( pszName );
    papoOpenDS[nOpenDSCount] = poDS;
    papoOpenDSDriver[nOpenDSCount] = poTempDriver;

    nOpenDSCount++;

    if( ppoDriver != NULL )
        *ppoDriver = poTempDriver;

    return poDS;
}

/************************************************************************/
/*                           OGROpenShared()                            */
/************************************************************************/

OGRDataSourceH OGROpenShared( const char *pszName, int bUpdate,
                              OGRSFDriverH *pahDriverList )

{
    OGRSFDriverRegistrar::GetRegistrar();
    return poRegistrar->OpenShared( pszName, bUpdate, 
                                    (OGRSFDriver **) pahDriverList );
}

/************************************************************************/
/*                         ReleaseDataSource()                          */
/************************************************************************/

OGRErr OGRSFDriverRegistrar::ReleaseDataSource( OGRDataSource * poDS )

{
    int iDS;

    for( iDS = 0; iDS < nOpenDSCount; iDS++ )
    {
        if( poDS == papoOpenDS[iDS] )
            break;
    }

    if( iDS == nOpenDSCount )
    {
        CPLDebug( "OGR", 
                  "ReleaseDataSource(%s/%p) on unshared datasource!\n"
                  "Deleting directly.", 
                  poDS->GetName(), poDS );
        delete poDS;
        return OGRERR_FAILURE;
    }

    if( poDS->GetRefCount() > 0 )
        poDS->Dereference();

    if( poDS->GetRefCount() > 0 )
    {
        CPLDebug( "OGR", 
                  "ReleaseDataSource(%s/%p) ... just dereferencing.",
                  poDS->GetName(), poDS );
        return OGRERR_NONE;
    }

    if( poDS->GetSummaryRefCount() > 0 )
    {
        CPLDebug( "OGR", 
                  "OGRSFDriverRegistrar::ReleaseDataSource(%s)\n"
                  "Datasource reference count is now zero, but some layers\n"
                  "are still referenced ... not closing datasource.",
                  poDS->GetName() );
        return OGRERR_FAILURE;
    }

/* -------------------------------------------------------------------- */
/*      We really want to close this file, and remove it from the       */
/*      shared list.                                                    */
/* -------------------------------------------------------------------- */
    CPLDebug( "OGR", 
              "ReleaseDataSource(%s/%p) dereferenced and now destroying.",
              poDS->GetName(), poDS );

    delete poDS;

    CPLFree( papszOpenDSRawName[iDS] );
    memmove( papszOpenDSRawName + iDS, papszOpenDSRawName + iDS + 1, 
             sizeof(char *) * (nOpenDSCount - iDS - 1) );
    memmove( papoOpenDS + iDS, papoOpenDS + iDS + 1, 
             sizeof(char *) * (nOpenDSCount - iDS - 1) );
    memmove( papoOpenDSDriver + iDS, papoOpenDSDriver + iDS + 1, 
             sizeof(char *) * (nOpenDSCount - iDS - 1) );

    nOpenDSCount--;

    if( nOpenDSCount == 0 )
    {
        CPLFree( papszOpenDSRawName );
        papszOpenDSRawName = NULL;
        CPLFree( papoOpenDS );
        papoOpenDS = NULL;
        CPLFree( papoOpenDSDriver );
        papoOpenDSDriver = NULL;
    }

    return OGRERR_NONE;
}

/************************************************************************/
/*                        OGRReleaseDataSource()                        */
/************************************************************************/

OGRErr OGRReleaseDataSource( OGRDataSourceH hDS )

{
    OGRSFDriverRegistrar::GetRegistrar();
    return poRegistrar->ReleaseDataSource((OGRDataSource *) hDS);
}

/************************************************************************/
/*                         OGRGetOpenDSCount()                          */
/************************************************************************/

int OGRGetOpenDSCount()

{
    OGRSFDriverRegistrar::GetRegistrar();
    return poRegistrar->GetOpenDSCount();
}

/************************************************************************/
/*                             GetOpenDS()                              */
/************************************************************************/

OGRDataSource *OGRSFDriverRegistrar::GetOpenDS( int iDS )

{
    if( iDS < 0 || iDS >= nOpenDSCount )
        return NULL;
    else
        return papoOpenDS[iDS];
}

/************************************************************************/
/*                            OGRGetOpenDS()                            */
/************************************************************************/

OGRDataSourceH OGRGetOpenDS( int iDS )

{
    OGRSFDriverRegistrar::GetRegistrar();
    return (OGRDataSourceH) poRegistrar->GetOpenDS( iDS );
}

/************************************************************************/
/*                           RegisterDriver()                           */
/************************************************************************/

void OGRSFDriverRegistrar::RegisterDriver( OGRSFDriver * poDriver )

{
    int         iDriver;

/* -------------------------------------------------------------------- */
/*      It has no effect to register a driver more than once.           */
/* -------------------------------------------------------------------- */
    for( iDriver = 0; iDriver < nDrivers; iDriver++ )
    {
        if( poDriver == papoDrivers[iDriver] )
            return;
    }                                                   

/* -------------------------------------------------------------------- */
/*      Add to the end of the driver list.                              */
/* -------------------------------------------------------------------- */
    papoDrivers = (OGRSFDriver **)
        CPLRealloc( papoDrivers, (nDrivers+1) * sizeof(void*) );

    papoDrivers[nDrivers++] = poDriver;
}

/************************************************************************/
/*                         OGRRegisterDriver()                          */
/************************************************************************/

void OGRRegisterDriver( OGRSFDriverH hDriver )

{
    poRegistrar->RegisterDriver( (OGRSFDriver *) hDriver );
}

/************************************************************************/
/*                           GetDriverCount()                           */
/************************************************************************/

int OGRSFDriverRegistrar::GetDriverCount()

{
    return nDrivers;
}

/************************************************************************/
/*                         OGRGetDriverCount()                          */
/************************************************************************/

int OGRGetDriverCount()

{
    if (poRegistrar)
        return poRegistrar->GetDriverCount();

    return 0;
}

/************************************************************************/
/*                             GetDriver()                              */
/************************************************************************/

OGRSFDriver *OGRSFDriverRegistrar::GetDriver( int iDriver )

{
    if( iDriver < 0 || iDriver >= nDrivers )
        return NULL;
    else
        return papoDrivers[iDriver];
}

/************************************************************************/
/*                            OGRGetDriver()                            */
/************************************************************************/

OGRSFDriverH OGRGetDriver( int iDriver )

{
    return (OGRSFDriverH) poRegistrar->GetDriver( iDriver );
}

/************************************************************************/
/*                          GetDriverByName()                           */
/************************************************************************/

OGRSFDriver *OGRSFDriverRegistrar::GetDriverByName( const char * pszName )

{
    for( int i = 0; i < nDrivers; i++ )
    {
        if( papoDrivers[i] != NULL 
            && EQUAL(papoDrivers[i]->GetName(),pszName) )
            return papoDrivers[i];
    }

    return NULL;
}

/************************************************************************/
/*                         OGRGetDriverByName()                         */
/************************************************************************/

OGRSFDriverH OGRGetDriverByName( const char *pszName )

{
    return (OGRSFDriverH) poRegistrar->GetDriverByName( pszName );
}