/*******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.util.graph.traverse;
import java.util.Iterator;
import java.util.Map;
import com.ibm.wala.util.collections.HashMapFactory;
import com.ibm.wala.util.collections.NonNullSingletonIterator;
import com.ibm.wala.util.graph.Graph;
/**
* This class implements depth-first search over a Graph, return an enumeration of the nodes of the graph in order of increasing
* finishing time. This class follows the outNodes of the graph nodes to define the graph, but this behavior can be changed by
* overriding the getConnected method.
*/
public class SlowDFSFinishTimeIterator<T> extends DFSFinishTimeIterator<T> {
public static final long serialVersionUID = 3903190104743762628L;
/**
* An iterator of child nodes for each node being searched
*/
final private Map<T, Iterator<T>> pendingChildren = HashMapFactory.make(25);
/**
* Construct a depth-first enumerator starting with a particular node in a directed graph.
*
* @param G the graph whose nodes to enumerate
* @throws IllegalArgumentException if G is null
*/
public SlowDFSFinishTimeIterator(Graph<T> G, T N) throws IllegalArgumentException {
if (G == null) {
throw new IllegalArgumentException("G is null");
}
if (!G.containsNode(N)) {
throw new IllegalArgumentException("source node not in graph: " + N);
}
init(G, new NonNullSingletonIterator<T>(N));
}
/**
* Construct a depth-first enumerator across the (possibly improper) subset of nodes reachable from the nodes in the given
* enumeration.
*
* @param G the graph whose nodes to enumerate
* @param nodes the set of nodes from which to start searching
*/
public SlowDFSFinishTimeIterator(Graph<T> G, Iterator<? extends T> nodes) {
if (G == null) {
throw new IllegalArgumentException("G is null");
}
if (nodes == null) {
throw new IllegalArgumentException("G is null");
}
init(G, nodes);
}
/**
* @throws NullPointerException if G is null
*/
public SlowDFSFinishTimeIterator(Graph<T> G) throws NullPointerException {
this(G, G == null ? null : G.iterator());
}
@Override
Iterator<T> getPendingChildren(T n) {
return pendingChildren.get(n);
}
@Override
void setPendingChildren(T v, Iterator<T> iterator) {
pendingChildren.put(v, iterator);
}
}