ogrfmelayercached.cpp

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

        poFMEFeature->resetFeature();

        poFMEFeature->setDimension( FME_TWO_D );
        poFMEFeature->setGeometryType( FME_GEOM_LINE );
        poFMEFeature->addCoordinate( oEnvelope.MinX, oEnvelope.MinY );
        poFMEFeature->addCoordinate( oEnvelope.MaxX, oEnvelope.MaxY );
            
        poIndex->queryEnvelope( *poFMEFeature );
    }

    bQueryActive = TRUE;

    poDS->ReleaseSession();
}

/************************************************************************/
/*                          GetFeatureCount()                           */
/************************************************************************/

int OGRFMELayerCached::GetFeatureCount( int bForce )

{
    int    nResult;

    poDS->AcquireSession();

    if( m_poAttrQuery != NULL || poIndex == NULL )
    {
        nResult = OGRLayer::GetFeatureCount( bForce );
    }
    else
    {
        ResetReading();
        nResult = poIndex->entries();
    }

    poDS->ReleaseSession();

    return nResult;
}

/************************************************************************/
/*                             GetExtent()                              */
/************************************************************************/

OGRErr OGRFMELayerCached::GetExtent( OGREnvelope *psExtent, int /* bForce */ )

{
    if( sExtents.MinX == 0.0 && sExtents.MaxX == 0.0
        && sExtents.MinY == 0.0 && sExtents.MaxY == 0.0 )
        return OGRERR_FAILURE;

    *psExtent = sExtents;

    return OGRERR_NONE;
}

/************************************************************************/
/*                           SerializeToXML()                           */
/************************************************************************/

CPLXMLNode *OGRFMELayerCached::SerializeToXML()

{
    CPLXMLNode      *psLayer;
    char            szGeomType[64];

    psLayer = CPLCreateXMLNode( NULL, CXT_Element, "OGRLayer" );
    
/* -------------------------------------------------------------------- */
/*      Handle various layer values.                                    */
/* -------------------------------------------------------------------- */
    CPLCreateXMLElementAndValue( psLayer, "Name", poFeatureDefn->GetName());
    sprintf( szGeomType, "%d", (int) poFeatureDefn->GetGeomType() );
    CPLCreateXMLElementAndValue( psLayer, "GeomType", szGeomType );    

    CPLCreateXMLElementAndValue( psLayer, "SpatialCacheName", 
                                 pszIndexBase );
    
/* -------------------------------------------------------------------- */
/*      Handle spatial reference if available.                          */
/* -------------------------------------------------------------------- */
    if( GetSpatialRef() != NULL )
    {
        char *pszWKT = NULL;
        OGRSpatialReference *poSRS = GetSpatialRef();
        
        poSRS->exportToWkt( &pszWKT );

        if( pszWKT != NULL )
        {
            CPLCreateXMLElementAndValue( psLayer, "SRS", pszWKT );
            CPLFree( pszWKT );
        }
    }

/* -------------------------------------------------------------------- */
/*      Handle extents if available.                                    */
/* -------------------------------------------------------------------- */
    OGREnvelope sEnvelope;
    if( GetExtent( &sEnvelope, FALSE ) == OGRERR_NONE )
    {
        char szExtent[512];

        sprintf( szExtent, "%24.15E,%24.15E,%24.15E,%24.15E", 
                 sEnvelope.MinX, sEnvelope.MinY, 
                 sEnvelope.MaxX, sEnvelope.MaxY );
        CPLCreateXMLElementAndValue( psLayer, "Extent", szExtent );
    }

/* -------------------------------------------------------------------- */
/*      Emit the field schemas.                                         */
/* -------------------------------------------------------------------- */
    CPLXMLNode *psSchema = CPLCreateXMLNode( psLayer, CXT_Element, "Schema" );
    
    for( int iField = 0; iField < poFeatureDefn->GetFieldCount(); iField++ )
    {
        OGRFieldDefn *poFieldDef = poFeatureDefn->GetFieldDefn( iField );
        const char *pszType;
        char szWidth[32], szPrecision[32];
        CPLXMLNode *psXMLFD;

        sprintf( szWidth, "%d", poFieldDef->GetWidth() );
        sprintf( szPrecision, "%d", poFieldDef->GetPrecision() );
        
        if( poFieldDef->GetType() == OFTInteger )
            pszType = "Integer";
        else if( poFieldDef->GetType() == OFTIntegerList )
            pszType = "IntegerList";
        else if( poFieldDef->GetType() == OFTReal )
            pszType = "Real";
        else if( poFieldDef->GetType() == OFTRealList )
            pszType = "RealList";
        else if( poFieldDef->GetType() == OFTString )
            pszType = "String";
        else if( poFieldDef->GetType() == OFTStringList )
            pszType = "StringList";
        else if( poFieldDef->GetType() == OFTWideString )
            pszType = "WideString";
        else if( poFieldDef->GetType() == OFTWideStringList )
            pszType = "WideStringList";
        else if( poFieldDef->GetType() == OFTBinary )
            pszType = "Binary";
        else
            pszType = "Unsupported";

        psXMLFD = CPLCreateXMLNode( psSchema, CXT_Element, "OGRFieldDefn" );
        CPLCreateXMLElementAndValue( psXMLFD, "Name",poFieldDef->GetNameRef());
        CPLCreateXMLElementAndValue( psXMLFD, "Type", pszType );
        CPLCreateXMLElementAndValue( psXMLFD, "Width", szWidth );
        CPLCreateXMLElementAndValue( psXMLFD, "Precision", szPrecision );
    }

    return psLayer;
}

/************************************************************************/
/*                         InitializeFromXML()                          */
/************************************************************************/

int OGRFMELayerCached::InitializeFromXML( CPLXMLNode *psLayer )

{
/* -------------------------------------------------------------------- */
/*      Create the feature definition.                                  */
/* -------------------------------------------------------------------- */
    poFeatureDefn = new OGRFeatureDefn( CPLGetXMLValue(psLayer,"Name","X") );
    
/* -------------------------------------------------------------------- */
/*      Set the geometry type, if available.                            */
/* -------------------------------------------------------------------- */
    if( CPLGetXMLNode( psLayer, "GeomType" ) != NULL )
        poFeatureDefn->SetGeomType( (OGRwkbGeometryType) 
                     atoi(CPLGetXMLValue( psLayer, "GeomType", "0" )) );

/* -------------------------------------------------------------------- */
/*      If we can extract extents, apply them to the layer.             */
/* -------------------------------------------------------------------- */
    if( CPLGetXMLNode( psLayer, "Extent" ) != NULL )
    {
        if( sscanf( CPLGetXMLValue( psLayer, "Extent", "" ), 
                    "%lf,%lf,%lf,%lf", 
                    &sExtents.MinX, 
                    &sExtents.MaxX, 
                    &sExtents.MinY, 
                    &sExtents.MaxY ) != 4 )
        {
            memset( &sExtents, 0, sizeof(sExtents) );
        }
    }

/* -------------------------------------------------------------------- */
/*      Apply a SRS if found in the XML.                                */
/* -------------------------------------------------------------------- */
    if( CPLGetXMLNode( psLayer, "SRS" ) != NULL )
    {
        char *pszSRS = (char *) CPLGetXMLValue( psLayer, "SRS", "" );
        OGRSpatialReference oSRS;

        if( oSRS.importFromWkt( &pszSRS ) == OGRERR_NONE )
        {
            if( poSpatialRef != NULL )
                delete poSpatialRef;

            poSpatialRef = oSRS.Clone();
        }
    }

/* -------------------------------------------------------------------- */
/*      Apply the Schema.                                               */
/* -------------------------------------------------------------------- */
    CPLXMLNode *psFieldDef;

    for( psFieldDef = CPLGetXMLNode( psLayer, "Schema.OGRFieldDefn" );
         psFieldDef != NULL; psFieldDef = psFieldDef->psNext )
    {
        const char *pszType;
        OGRFieldType eType;

        if( !EQUAL(psFieldDef->pszValue,"OGRFieldDefn") )
            continue;

        pszType = CPLGetXMLValue( psFieldDef, "type", "String" );
        if( EQUAL(pszType,"String") )
            eType = OFTString;
        else if( EQUAL(pszType,"StringList") )
            eType = OFTStringList;
        else if( EQUAL(pszType,"Integer") )
            eType = OFTInteger;
        else if( EQUAL(pszType,"IntegerList") )
            eType = OFTIntegerList;
        else if( EQUAL(pszType,"Real") )
            eType = OFTReal;
        else if( EQUAL(pszType,"RealList") )
            eType = OFTRealList;
        else if( EQUAL(pszType,"WideString") )
            eType = OFTWideString;
        else if( EQUAL(pszType,"WideStringList") )
            eType = OFTWideStringList;
        else if( EQUAL(pszType,"Binary") )
            eType = OFTBinary;
        else
            eType = OFTString;

        OGRFieldDefn oField( CPLGetXMLValue( psFieldDef, "name", "default" ),
                             eType );

        oField.SetWidth( atoi(CPLGetXMLValue(psFieldDef,"width","0")) );
        oField.SetPrecision( atoi(CPLGetXMLValue(psFieldDef,"precision","0")));

        poFeatureDefn->AddFieldDefn( &oField );
    }

/* -------------------------------------------------------------------- */
/*      Ensure we have a working string and feature object              */
/* -------------------------------------------------------------------- */
    poFMEFeature = poDS->GetFMESession()->createFeature();

    return TRUE;
}