/*
* 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.Iterator ;
import org.apache.jena.atlas.iterator.Iter ;
import org.apache.jena.atlas.lib.Lib ;
import com.hp.hpl.jena.graph.Graph ;
import com.hp.hpl.jena.graph.Node ;
import com.hp.hpl.jena.shared.JenaException ;
/** Base class for implementations of a DatasetGraph as a set of graphs.
* This can be a fixed collection or a changeable collection depending
* on the implementation of getDefaultGraph()/getGraph(Node)
*/
public abstract class DatasetGraphCollection extends DatasetGraphBaseFind
{
@Override
public void add(Quad quad)
{
Graph g = fetchGraph(quad.getGraph()) ;
if ( g == null )
throw new JenaException("No such graph: "+quad.getGraph()) ;
g.add(quad.asTriple()) ;
}
@Override
public void delete(Quad quad)
{
Graph g = fetchGraph(quad.getGraph()) ;
if ( g == null )
throw new JenaException("No such graph: "+quad.getGraph()) ;
g.delete(quad.asTriple()) ;
}
@Override
protected Iterator<Quad> findInDftGraph(Node s, Node p , Node o)
{
return triples2quadsDftGraph(getDefaultGraph().find(s, p, o)) ;
}
@Override
protected Iter<Quad> findInSpecificNamedGraph(Node g, Node s, Node p , Node o)
{
Graph graph = fetchGraph(g) ;
if ( g == null )
return Iter.nullIter() ;
return triples2quads(g, graph.find(s, p, o)) ;
}
@Override
protected Iterator<Quad> findInAnyNamedGraphs(Node s, Node p, Node o)
{
Iterator<Node> gnames = listGraphNodes() ;
Iterator<Quad> iter = null ;
// Named graphs
for ( ; gnames.hasNext() ; )
{
Node gn = gnames.next();
Iterator<Quad> qIter = findInSpecificNamedGraph(gn, s, p, o) ;
if ( qIter != null )
// copes with null for iter
iter = Iter.append(iter, qIter) ;
}
return iter ;
}
@Override
public abstract Iterator<Node> listGraphNodes() ;
protected Graph fetchGraph(Node gn)
{
if ( Quad.isDefaultGraph(gn) || Lib.equal(gn,Quad.tripleInQuad)) // Not preferrred style
return getDefaultGraph() ;
else
return getGraph(gn) ;
}
}