storm-client/src/jvm/org/apache/storm/messaging/netty/MessageBuffer.java

/**
 * 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.storm.messaging.netty;

import org.apache.storm.messaging.TaskMessage;

/**
 * Encapsulates the state used for batching up messages.
 */
public class MessageBuffer {
    private final int mesageBatchSize;
    private MessageBatch currentBatch;

    public MessageBuffer(int mesageBatchSize) {
        this.mesageBatchSize = mesageBatchSize;
        this.currentBatch = new MessageBatch(mesageBatchSize);
    }

    public synchronized MessageBatch add(TaskMessage msg) {
        currentBatch.add(msg);
        if (currentBatch.isFull()) {
            MessageBatch ret = currentBatch;
            currentBatch = new MessageBatch(mesageBatchSize);
            return ret;
        } else {
            return null;
        }
    }

    public synchronized boolean isEmpty() {
        return currentBatch.isEmpty();
    }

    public synchronized MessageBatch drain() {
        if (!currentBatch.isEmpty()) {
            MessageBatch ret = currentBatch;
            currentBatch = new MessageBatch(mesageBatchSize);
            return ret;
        } else {
            return null;
        }
    }
}