/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hp.hpl.jena.sparql.core;
import java.util.HashMap ;
import java.util.Map ;
import com.hp.hpl.jena.graph.Graph ;
import com.hp.hpl.jena.graph.Node ;
import com.hp.hpl.jena.sparql.graph.GraphReadOnly ;
/** Read-only view of a DatasetGraph. Assumes the dataset underneath isn't changing.
*/
public class DatasetGraphReadOnly extends DatasetGraphWrapper
{
public DatasetGraphReadOnly(DatasetGraph dsg) { super(dsg) ; }
private Graph dftGraph = null ;
@Override
public Graph getDefaultGraph()
{
if ( dftGraph == null )
dftGraph = new GraphReadOnly(super.getDefaultGraph()) ;
return dftGraph ;
}
private Map<Node, Graph> namedGraphs = new HashMap<>() ;
@Override
public Graph getGraph(Node graphNode)
{
if ( namedGraphs.containsKey(graphNode) )
{
if ( ! super.containsGraph(graphNode) )
{
namedGraphs.remove(graphNode) ;
return null ;
}
return namedGraphs.get(graphNode) ;
}
Graph g = super.getGraph(graphNode) ;
if ( g == null ) return null ;
g = new GraphReadOnly(g) ;
namedGraphs.put(graphNode, g) ;
return g ;
}
@Override
public void setDefaultGraph(Graph g)
{ throw new UnsupportedOperationException("read-only dataset") ; }
@Override
public void addGraph(Node graphName, Graph graph)
{ throw new UnsupportedOperationException("read-only dataset") ; }
@Override
public void removeGraph(Node graphName)
{ throw new UnsupportedOperationException("read-only dataset") ; }
@Override
public void add(Quad quad)
{ throw new UnsupportedOperationException("read-only dataset") ; }
@Override
public void delete(Quad quad)
{ throw new UnsupportedOperationException("read-only dataset") ; }
@Override
public void deleteAny(Node g, Node s, Node p, Node o)
{ throw new UnsupportedOperationException("read-only dataset") ; }
}