org.jgrapht.graph.DefaultGraphSpecificsStrategy Maven / Gradle / Ivy
/*
* (C) Copyright 2018-2023, by Dimitrios Michail 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;
import org.jgrapht.*;
import org.jgrapht.graph.specifics.*;
import java.io.*;
import java.util.*;
import java.util.function.*;
/**
* A default lookup specifics strategy implementation.
*
*
* Graphs constructed using this strategy require the least amount of memory, at the expense of slow
* edge retrievals. Methods which depend on edge retrievals, e.g. getEdge(V u, V v), containsEdge(V
* u, V v), addEdge(V u, V v), etc may be relatively slow when the average degree of a vertex is
* high (dense graphs). For a fast implementation, use {@link FastLookupGraphSpecificsStrategy}.
*
* @author Dimitrios Michail
*
* @param the graph vertex type
* @param the graph edge type
*/
public class DefaultGraphSpecificsStrategy
implements GraphSpecificsStrategy
{
private static final long serialVersionUID = 7615319421753562075L;
@Override
public Function> getIntrusiveEdgesSpecificsFactory()
{
return (Function> & Serializable) (type) -> {
if (type.isWeighted()) {
return new WeightedIntrusiveEdgesSpecifics(new LinkedHashMap<>());
} else {
return new UniformIntrusiveEdgesSpecifics<>(new LinkedHashMap<>());
}
};
}
@Override
public BiFunction, GraphType, Specifics> getSpecificsFactory()
{
return (BiFunction, GraphType,
Specifics> & Serializable) (graph, type) -> {
if (type.isDirected()) {
return new DirectedSpecifics(
graph, new LinkedHashMap<>(), getEdgeSetFactory());
} else {
return new UndirectedSpecifics<>(
graph, new LinkedHashMap<>(), getEdgeSetFactory());
}
};
}
}