org.jgrapht.graph.specifics.DirectedEdgeContainer Maven / Gradle / Ivy
/*
* (C) Copyright 2015-2023, by Barak Naveh and Contributors.
*
* JGraphT : a free Java graph-theory library
*
* See the CONTRIBUTORS.md file distributed with this work for additional
* information regarding copyright ownership.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0, or the
* GNU Lesser General Public License v2.1 or later
* which is available at
* http://www.gnu.org/licenses/old-licenses/lgpl-2.1-standalone.html.
*
* SPDX-License-Identifier: EPL-2.0 OR LGPL-2.1-or-later
*/
package org.jgrapht.graph.specifics;
import org.jgrapht.graph.*;
import java.io.*;
import java.util.*;
/**
* A container for vertex edges.
*
*
* In this edge container we use array lists to minimize memory toll. However, for high-degree
* vertices we replace the entire edge container with a direct access subclass (to be implemented).
*
* @param the graph vertex type
* @param the graph edge type
*
* @author Barak Naveh
*/
public class DirectedEdgeContainer
implements Serializable
{
private static final long serialVersionUID = 7494242245729767106L;
Set incoming;
Set outgoing;
private transient Set unmodifiableIncoming = null;
private transient Set unmodifiableOutgoing = null;
DirectedEdgeContainer(EdgeSetFactory edgeSetFactory, V vertex)
{
incoming = edgeSetFactory.createEdgeSet(vertex);
outgoing = edgeSetFactory.createEdgeSet(vertex);
}
/**
* A lazy build of unmodifiable incoming edge set.
*
* @return an unmodifiable version of the incoming edge set
*/
public Set getUnmodifiableIncomingEdges()
{
if (unmodifiableIncoming == null) {
unmodifiableIncoming = Collections.unmodifiableSet(incoming);
}
return unmodifiableIncoming;
}
/**
* A lazy build of unmodifiable outgoing edge set.
*
* @return an unmodifiable version of the outgoing edge set
*/
public Set getUnmodifiableOutgoingEdges()
{
if (unmodifiableOutgoing == null) {
unmodifiableOutgoing = Collections.unmodifiableSet(outgoing);
}
return unmodifiableOutgoing;
}
/**
* Add an incoming edge.
*
* @param e the edge to add
*/
public void addIncomingEdge(E e)
{
incoming.add(e);
}
/**
* Add an outgoing edge.
*
* @param e the edge to add
*/
public void addOutgoingEdge(E e)
{
outgoing.add(e);
}
/**
* Remove an incoming edge.
*
* @param e the edge to remove
*/
public void removeIncomingEdge(E e)
{
incoming.remove(e);
}
/**
* Remove an outgoing edge.
*
* @param e the edge to remove
*/
public void removeOutgoingEdge(E e)
{
outgoing.remove(e);
}
}