org.jgrapht.graph.guava.ImmutableNetworkAdapter Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jgrapht-guava Show documentation
There is a newer version: 1.5.2
/*
 * (C) Copyright 2018-2018, by Dimitrios Michail and Contributors.
 *
 * JGraphT : a free Java graph-theory library
 *
 * This program and the accompanying materials are dual-licensed under
 * either
 *
 * (a) the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation, or (at your option) any
 * later version.
 *
 * or (per the licensee's choosing)
 *
 * (b) the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation.
 */
package org.jgrapht.graph.guava;

import com.google.common.graph.Graphs;
import com.google.common.graph.*;
import org.jgrapht.Graph;
import org.jgrapht.*;
import org.jgrapht.util.*;

import java.io.*;

/**
 * A graph adapter class using Guava's {@link ImmutableNetwork}.
 * 
 * 
 * Since the underlying network is immutable, the resulting graph is unmodifiable.
 * 
 * 

 * Example usage: 

 * 
 *  * MutableNetwork<String, DefaultEdge> mutableNetwork =
 *     NetworkBuilder.directed().allowsParallelEdges(true).allowsSelfLoops(true).build();
 * 
 * mutableNetwork.addNode("v1");
 * 
 * ImmutableNetworkGraph<String, DefaultEdge> immutableNetwork =
 *     ImmutableNetwork.copyOf(mutableNetwork);
 * 
 * Graph<String, DefaultEdge> graph = new ImmutableNetworkAdapter<>(immutableNetwork);
 * 
 * 
 * 
 * 
 * @author Dimitrios Michail
 *
 * @param  the graph vertex type
 * @param  the graph edge type
 */
public class ImmutableNetworkAdapter
    extends
    BaseNetworkAdapter>
    implements
    Graph,
    Cloneable,
    Serializable
{
    private static final long serialVersionUID = 8776276294297681092L;

    protected static final String GRAPH_IS_IMMUTABLE = "Graph is immutable";

    /**
     * Create a new network adapter.
     * 
     * @param network the immutable network
     */
    public ImmutableNetworkAdapter(ImmutableNetwork network)
    {
        super(network);
    }

    @Override
    public E addEdge(V sourceVertex, V targetVertex)
    {
        throw new UnsupportedOperationException(GRAPH_IS_IMMUTABLE);
    }

    @Override
    public boolean addEdge(V sourceVertex, V targetVertex, E e)
    {
        throw new UnsupportedOperationException(GRAPH_IS_IMMUTABLE);
    }

    @Override
    public V addVertex()
    {
        throw new UnsupportedOperationException(GRAPH_IS_IMMUTABLE);
    }

    @Override
    public boolean addVertex(V v)
    {
        throw new UnsupportedOperationException(GRAPH_IS_IMMUTABLE);
    }

    @Override
    public E removeEdge(V sourceVertex, V targetVertex)
    {
        throw new UnsupportedOperationException(GRAPH_IS_IMMUTABLE);
    }

    @Override
    public boolean removeEdge(E e)
    {
        throw new UnsupportedOperationException(GRAPH_IS_IMMUTABLE);
    }

    @Override
    public boolean removeVertex(V v)
    {
        throw new UnsupportedOperationException(GRAPH_IS_IMMUTABLE);
    }

    @Override
    public double getEdgeWeight(E e)
    {
        return Graph.DEFAULT_EDGE_WEIGHT;
    }

    @Override
    public void setEdgeWeight(E e, double weight)
    {
        throw new UnsupportedOperationException("Graph is unweighted");
    }

    @Override
    public GraphType getType()
    {
        return super.getType().asUnmodifiable();
    }

    /**
     * Returns a shallow copy of this graph instance. Neither edges nor vertices are cloned.
     *
     * @return a shallow copy of this graph.
     *
     * @throws RuntimeException in case the clone is not supported
     *
     * @see java.lang.Object#clone()
     */
    @Override
    public Object clone()
    {
        try {
            ImmutableNetworkAdapter newGraph = TypeUtil.uncheckedCast(super.clone());

            newGraph.vertexSupplier = this.vertexSupplier;
            newGraph.edgeSupplier = this.edgeSupplier;
            newGraph.unmodifiableVertexSet = null;
            newGraph.unmodifiableEdgeSet = null;
            newGraph.network = ImmutableNetwork.copyOf(Graphs.copyOf(this.network));

            return newGraph;
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
            throw new RuntimeException();
        }
    }

    private void writeObject(ObjectOutputStream oos)
        throws IOException
    {
        oos.defaultWriteObject();

        // write type
        oos.writeObject(getType());

        // write vertices
        int n = vertexSet().size();
        oos.writeInt(n);
        for (V v : vertexSet()) {
            oos.writeObject(v);
        }

        // write edges
        int m = edgeSet().size();
        oos.writeInt(m);
        for (E e : edgeSet()) {
            oos.writeObject(getEdgeSource(e));
            oos.writeObject(getEdgeTarget(e));
            oos.writeObject(e);
        }
    }

    @SuppressWarnings("unchecked")
    private void readObject(ObjectInputStream ois)
        throws ClassNotFoundException,
        IOException
    {
        ois.defaultReadObject();

        GraphType type = (GraphType) ois.readObject();
        if (type.isMixed()) {
            throw new IOException("Graph type not supported");
        }

        MutableNetwork mutableNetwork =
            (type.isDirected() ? NetworkBuilder.directed() : NetworkBuilder.undirected())
                .allowsParallelEdges(type.isAllowingMultipleEdges())
                .allowsSelfLoops(type.isAllowingSelfLoops()).build();

        // read vertices
        int n = ois.readInt();
        for (int i = 0; i < n; i++) {
            V v = (V) ois.readObject();
            mutableNetwork.addNode(v);
        }

        // read edges
        int m = ois.readInt();
        for (int i = 0; i < m; i++) {
            V s = (V) ois.readObject();
            V t = (V) ois.readObject();
            E e = (E) ois.readObject();
            mutableNetwork.addEdge(s, t, e);
        }

        // setup the immutable copy
        this.network = ImmutableNetwork.copyOf(mutableNetwork);
    }

}