content: /**
   * 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 com.alibaba.jstorm.message.netty;
  
  import java.util.List;
  
  import backtype.storm.messaging.NettyMessage;
  
  
  /**
   * Encapsulates the state used for batching up messages.
   */
  public class MessageBuffer {
      private final int messageBatchSize;
      private MessageBatch currentBatch;
  
      public MessageBuffer(int messageBatchSize) {
          this.messageBatchSize = messageBatchSize;
          this.currentBatch = new MessageBatch(messageBatchSize);
      }
  
      public void setMessageBatch(MessageBatch batch) {
          this.currentBatch = batch;
      }
  
      public MessageBatch add(NettyMessage msg) {
          return add(msg, true);
      }
  
      /**
       * @param msg        netty message
       * @param isFlushed, true: return batch when batch is full
       *                   false: just add message
       * @return message batch if available
       */
      public MessageBatch add(NettyMessage msg, boolean isFlushed) {
          currentBatch.add(msg);
          if (isFlushed && currentBatch.isFull()) {
              MessageBatch ret = currentBatch;
              currentBatch = new MessageBatch(messageBatchSize);
              return ret;
          } else {
              return null;
          }
      }
  
      public MessageBatch add(List<NettyMessage> msgs) {
          return add(msgs, true);
      }
  
      /**
       * @param msgs       a list of netty messages
       * @param isFlushed, true: return batch when batch is full
       *                   false: just add message
       * @return message batch if available
       */
      public MessageBatch add(List<NettyMessage> msgs, boolean isFlushed) {
          currentBatch.add(msgs);
          if (currentBatch.isFull() && isFlushed) {
              MessageBatch ret = currentBatch;
              currentBatch = new MessageBatch(messageBatchSize);
              return ret;
          } else {
              return null;
          }
      }
  
  
      public boolean isEmpty() {
          return currentBatch.isEmpty();
      }
  
      public int size() {
          return currentBatch.getEncodedLength();
      }
  
      public MessageBatch drain() {
          if (!currentBatch.isEmpty()) {
              MessageBatch ret = currentBatch;
              currentBatch = new MessageBatch(messageBatchSize);
              return ret;
          } else {
              return null;
          }
      }
  
      public void clear() {
          currentBatch = new MessageBatch(messageBatchSize);
      }
  }