/*
* Copyright (c) 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
*
* 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:
* bstefanescu
*/
package org.eclipse.ecr.core.event.impl;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* A map used to track duplicates.
* <p>
* This class is not synchronized on read; this means you need to populate the
* map before using it.
*
* @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
*/
public class AssocMap {
protected final Map<String, Set<String>> peers = new HashMap<String, Set<String>>();
public synchronized void put(String x, String y) {
Set<String> px = peers.get(x);
Set<String> py = peers.get(y);
if (px == py) {
return; // already associated
}
if (px == null) {
py.add(x);
peers.put(x, py);
} else if (py == null) {
px.add(y);
peers.put(y, px);
} else { // both members are already in relation with other members
Set<String> set = new HashSet<String>();
set.addAll(px);
set.addAll(py);
for (String key : set.toArray(new String[set.size()])) {
peers.put(key, set);
}
}
}
public boolean isPeerOf(String x, String y) {
Set<String> set = peers.get(x);
return set != null && set.contains(y);
}
}