QuickFIXMessageCache.java

/* 
 * Copyright 2003,2004,2005 Colin Crist
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */

package hermes.fix.quickfix;

import hermes.fix.FIXMessage;

import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

import org.apache.commons.collections.map.LRUMap;

import quickfix.Message;
import quickfix.mina.message.FIXMessageDecoder;

/**
 * @author colincrist@hermesjms.com
 * @version $Id: QuickFIXMessageCache.java,v 1.1 2006/07/26 09:47:56 colincrist
 *          Exp $
 */

public class QuickFIXMessageCache {
	private LRUMap messages;
	private Set<FIXMessage> toReset = new HashSet<FIXMessage>();
	private Lock lock = new ReentrantLock();

	private Map<Thread, FIXMessageDecoder> decoders = new HashMap<Thread, FIXMessageDecoder>();

	public QuickFIXMessageCache() {
		this(1024);
	}

	public FIXMessageDecoder getDecoder() throws UnsupportedEncodingException {
		synchronized (decoders) {
			FIXMessageDecoder decoder = decoders.get(Thread.currentThread());

			if (decoder == null) {
				decoder = new FIXMessageDecoder();
				decoders.put(Thread.currentThread(), decoder);
			}

			return decoder;
		}
	}

	public QuickFIXMessageCache(int size) {
		messages = createLRUMap(size);
	}

	private LRUMap createLRUMap(int size) {
		return new LRUMap(size) {
			/**
		 * 
		 */
			private static final long serialVersionUID = -3353399913762901038L;

			@Override
			protected boolean removeLRU(LinkEntry entry) {
				//
				// When the message is removed from the cache clear its fields.

				final FIXMessage message = (FIXMessage) entry.getKey();

				// We cannot call reset here, the next time a put occurs, we'll
				// reset it.

				synchronized (toReset) {
					toReset.add(message);
				}

				return super.removeLRU(entry);
			}
		};
	}

	public void setSize(int size) {
		lock.lock();

		try {
			final LRUMap newMessages = createLRUMap(size);

			messages.putAll(newMessages);
			messages = newMessages;
		} finally {
			lock.unlock();
		}
	}

	public int getSize() {
		lock.lock();

		try {
			if (messages == null) {
				return 0;
			} else {
				return messages.maxSize();
			}
		} finally {
			lock.unlock();
		}
	}

	public void close() {
		lock.lock();

		try {
			messages.clear();
			decoders.clear();

		} finally {
			lock.unlock();
		}

		synchronized (toReset) {
			toReset.clear();
		}
	}

	public void lock() {
		lock.lock();
	}

	public void unlock() {
		lock.unlock();
	}

	public boolean contains(FIXMessage key) {
		lock.lock();

		try {
			return messages.containsKey(key);
		} finally {
			lock.unlock();
		}
	}

	public void put(FIXMessage key, Message value) {
		lock.lock();

		try {
			messages.put(key, value);
		} finally {
			lock.unlock();
		}

		synchronized (toReset) {
			if (toReset.contains(key)) {
				toReset.remove(key);
			}

			for (FIXMessage m : toReset) {
				m.reset();
			}

			toReset.clear();
		}

	}

	public Message get(FIXMessage key) {
		lock.lock();

		try {
			return (Message) messages.get(key);
		} finally {
			lock.unlock();
		}
	}
}