/*******************************************************************************
 *Copyright (c) 2009  Eucalyptus Systems, Inc.
 * 
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, only version 3 of the License.
 * 
 * 
 *  This file 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 General Public License
 *  for more details.
 * 
 *  You should have received a copy of the GNU General Public License along
 *  with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 *  Please contact Eucalyptus Systems, Inc., 130 Castilian
 *  Dr., Goleta, CA 93101 USA or visit <http://www.eucalyptus.com/licenses/>
 *  if you need additional information or have any questions.
 * 
 *  This file may incorporate work covered under the following copyright and
 *  permission notice:
 * 
 *    Software License Agreement (BSD License)
 * 
 *    Copyright (c) 2008, Regents of the University of California
 *    All rights reserved.
 * 
 *    Redistribution and use of this software in source and binary forms, with
 *    or without modification, are permitted provided that the following
 *    conditions are met:
 * 
 *      Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 * 
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 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 * 
 *    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 *    IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 *    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 *    PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
 *    OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 *    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 *    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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 *    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. USERS OF
 *    THIS SOFTWARE ACKNOWLEDGE THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE
 *    LICENSED MATERIAL, COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS
 *    SOFTWARE, AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING
 *    IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA, SANTA
 *    BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, WHICH IN
 *    THE REGENTS’ DISCRETION MAY INCLUDE, WITHOUT LIMITATION, REPLACEMENT
 *    OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO IDENTIFIED, OR
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 *******************************************************************************/
/*
 *
 * Author: Sunil Soman sunils@cs.ucsb.edu
 */
package edu.ucsb.eucalyptus.util;

import java.util.concurrent.ConcurrentHashMap;
import org.apache.log4j.Logger;

// A concurrent hash map that holds a map of queues, which can be used for passing data
// Currently, the queues are a WalrusDataQueue and producers/consumers do not timeout.

public class WalrusDataMessenger {
	private static Logger LOG = Logger.getLogger( WalrusDataMessenger.class );
	private static final int DATA_QUEUE_SIZE = 3;

	private ConcurrentHashMap<String, ConcurrentHashMap<String,WalrusDataQueue<WalrusDataMessage>>> queueMap;
	private ConcurrentHashMap<String, WalrusMonitor> monitorMap;

	public WalrusDataMessenger() {
		queueMap = new ConcurrentHashMap<String, ConcurrentHashMap<String,WalrusDataQueue<WalrusDataMessage>>>();
		monitorMap = new ConcurrentHashMap<String, WalrusMonitor>();
	}

	public WalrusDataQueue<WalrusDataMessage> getQueue(String key1, String key2) {
		ConcurrentHashMap<String,WalrusDataQueue<WalrusDataMessage>> queues = queueMap.putIfAbsent(key1, new ConcurrentHashMap<String, WalrusDataQueue<WalrusDataMessage>>());
		if (queues == null) {
			queues = queueMap.get(key1);
		}
		WalrusDataQueue<WalrusDataMessage> queue = queues.putIfAbsent(key2, new WalrusDataQueue<WalrusDataMessage>(DATA_QUEUE_SIZE));
		if (queue == null) {
			queue = queues.get(key2);
		}
		return queue;
	}

	public WalrusDataQueue<WalrusDataMessage> interruptAllAndGetQueue(String key1, String key2) {
		ConcurrentHashMap<String,WalrusDataQueue<WalrusDataMessage>> queues = queueMap.get(key1);
		if(queues != null) {
			for (WalrusDataQueue<WalrusDataMessage> queue: queues.values()) {
				queue.setInterrupted(true);
			}
		}
		return getQueue(key1, key2);
	}

	public void removeQueue(String key1, String key2) {
		if(queueMap.containsKey(key1)) {
			ConcurrentHashMap<String, WalrusDataQueue<WalrusDataMessage>> queues = queueMap.get(key1);
			if(queues.containsKey(key2)) {
				queues.remove(key2);
			}
		}
	}

	public WalrusMonitor getMonitor(String key) {
		WalrusMonitor monitor = monitorMap.putIfAbsent(key, new WalrusMonitor());
		if (monitor == null) {
			monitor = monitorMap.get(key);
		}
		return monitor;
	}

	public void removeMonitor(String key) {
		if(monitorMap.containsKey(key)) {
			monitorMap.remove(key);
		}
	}
}