/*
 * 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.
 */

package org.apache.giraph.comm;

import org.apache.giraph.graph.BspUtils;
import org.apache.hadoop.io.Writable;

/**
 * Wrapper around {@link ArrayListWritable} that allows the message class to
 * be set prior to calling readFields().
 *
 * @param <M> message type
 */
public class MsgList<M extends Writable>
    extends ArrayListWritable<M> {
    /** Defining a layout version for a serializable class. */
    private static final long serialVersionUID = 100L;

    public MsgList() {
        super();
    }
    
    public MsgList(MsgList<M> msgList) {
        super(msgList);
    }

    @SuppressWarnings("unchecked")
    @Override
    public void setClass() {
        setClass((Class<M>) BspUtils.getMessageValueClass(getConf()));
    }
}