/*
* JBoss, Home of Professional Open Source
* Copyright 2010, Red Hat Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt 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.ee.component.interceptors;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import static java.lang.Integer.toHexString;
import org.jboss.as.ee.logging.EeLogger;
/**
* Container for an ordered list of object. Objects are added to the container, and can be sorted and
* retrieved via {@link #getSortedItems()}. In order to prevent excessive sorts once the sort has been performed
* no new objects can be added.
* <p/>
* The sort is guaranteed to be stable, so adding multiple objects with the same priority means that they will be
* run in the order that they were added.
*
* @author Stuart Douglas
*/
public class OrderedItemContainer<T> {
private final Map<Integer, T> items = new HashMap<Integer, T>();
private volatile List<T> sortedItems;
public void add(final T item, int priority) {
if(sortedItems != null) {
throw EeLogger.ROOT_LOGGER.cannotAddMoreItems();
}
if(item == null) {
throw EeLogger.ROOT_LOGGER.nullVar("item");
}
final T current = items.get(priority);
if (current != null) {
throw EeLogger.ROOT_LOGGER.priorityAlreadyExists(item, toHexString(priority), current);
}
items.put(priority, item);
}
public List<T> getSortedItems() {
if(sortedItems == null) {
final SortedMap<Integer, T> sortedMap = new TreeMap<Integer, T>(items);
sortedItems = new ArrayList<T>(sortedMap.values());
}
return sortedItems;
}
}