/*
* JBoss, Home of Professional Open Source.
* Copyright 2010, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.as.connector.util;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
public class CopyOnWriteArrayListMultiMap<K, V> {
private final ConcurrentMap<K, List<V>> cache = new ConcurrentHashMap<K, List<V>>();
public List<V> get(K k) {
return cache.get(k);
}
public synchronized List<V> remove(K k) {
return cache.remove(k);
}
public synchronized void putIfAbsent(K k, V v) {
List<V> list = cache.get(k);
if (list == null || list.isEmpty()) {
list = new ArrayList<V>();
} else {
list = new ArrayList<V>(list);
}
if (!list.contains(v)) {
list.add(v);
cache.put(k, list);
}
}
public synchronized boolean remove(K k, K v) {
List<V> list = cache.get(k);
if (list == null) {
return false;
}
if (list.isEmpty()) {
cache.remove(k);
return false;
}
boolean removed = list.remove(v);
if (removed) {
if (list.isEmpty()) {
cache.remove(k);
} else {
list = new ArrayList<V>(list);
cache.put(k, list);
}
}
return removed;
}
}