package org.apache.cassandra.net;
/*
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 * 
 */


import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class CachingMessageProducer implements MessageProducer
{
    private final MessageProducer prod;
    private final Map<Integer, Message> messages = new HashMap<Integer, Message>(2);

    public CachingMessageProducer(MessageProducer prod)
    {
        this.prod = prod;    
    }

    public synchronized Message getMessage(Integer version) throws IOException
    {
        Message msg = messages.get(version);
        if (msg == null)
        {
            msg = prod.getMessage(version);
            messages.put(version, msg);
        }
        return msg;
    }
}