/*******************************************************************************
* 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.dominators;
import java.util.Map;
import com.ibm.wala.util.collections.HashMapFactory;
import com.ibm.wala.util.graph.Graph;
/**
* Calculate dominators using Langauer and Tarjan's fastest algorithm. TOPLAS
* 1(1), July 1979. This implementation uses path compression and results in a
* O(e * alpha(e,n)) complexity, where e is the number of edges in the CFG and n
* is the number of nodes.
*
* Sources: TOPLAS article, Muchnick book
*/
public class GenericDominators<T> extends Dominators<T> {
public GenericDominators(Graph<T> G, T root)
throws IllegalArgumentException
{
super(G, root);
this.infoMap = HashMapFactory.make(G.getNumberOfNodes());
analyze();
}
/*
* Look-aside table for DominatorInfo objects
*/
private final Map<Object, DominatorInfo> infoMap;
@Override
protected DominatorInfo getInfo(T node) {
if (!infoMap.containsKey(node))
infoMap.put(node, new DominatorInfo(node));
return infoMap.get(node);
}
}