    001/*
    002 * Copyright (c) 2007-2016 Concurrent, Inc. All Rights Reserved.
    003 *
    004 * Project and contact information: http://www.cascading.org/
    005 *
    006 * This file is part of the Cascading project.
    007 *
    008 * Licensed under the Apache License, Version 2.0 (the "License");
    009 * you may not use this file except in compliance with the License.
    010 * You may obtain a copy of the License at
    011 *
    012 *     http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing, software
    015 * distributed under the License is distributed on an "AS IS" BASIS,
    016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    017 * See the License for the specific language governing permissions and
    018 * limitations under the License.
    019 */
    020
    021package cascading.flow.planner.graph;
    022
    023import java.util.Collection;
    024import java.util.Set;
    025
    026import cascading.flow.FlowElement;
    027import cascading.flow.planner.Scope;
    028import org.jgrapht.DirectedGraph;
    029import org.jgrapht.graph.DirectedSubgraph;
    030
    031import static cascading.flow.planner.graph.ElementGraphs.directed;
    032import static cascading.util.Util.createIdentitySet;
    033
    034/**
    035 *
    036 */
    037public class ElementSubGraph extends BaseElementGraph implements ElementGraph
    038  {
    039  private final ElementGraph elementGraph;
    040  private final Set<FlowElement> flowElements;
    041  private final Set<Scope> scopes;
    042
    043  public ElementSubGraph( ElementGraph elementGraph, Collection<FlowElement> flowElements )
    044    {
    045    this( elementGraph, flowElements, null );
    046    }
    047
    048  public ElementSubGraph( ElementGraph elementGraph, Collection<FlowElement> flowElements, Collection<Scope> scopes )
    049    {
    050    this.flowElements = createIdentitySet( flowElements );
    051    this.scopes = scopes == null || scopes.isEmpty() ? null : createIdentitySet( scopes ); // forces edges to be induced
    052    this.graph = new DirectedSubGraph( directed( elementGraph ), this.flowElements, this.scopes );
    053    this.elementGraph = elementGraph;
    054    }
    055
    056  public ElementSubGraph( ElementSubGraph graph )
    057    {
    058    this( graph.elementGraph, graph.flowElements, graph.scopes );
    059    }
    060
    061  @Override
    062  public ElementGraph copyElementGraph()
    063    {
    064    return new ElementSubGraph( this );
    065    }
    066
    067  private class DirectedSubGraph extends DirectedSubgraph<FlowElement, Scope>
    068    {
    069    public DirectedSubGraph( DirectedGraph<FlowElement, Scope> base, Set<FlowElement> vertexSubset, Set<Scope> edgeSubset )
    070      {
    071      super( base, vertexSubset, edgeSubset );
    072      }
    073    }
    074  }