content: /*
   * Copyright 1999-2012 Alibaba Group.
   *  
   * 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 com.alibaba.cobar.net.mysql;
  
  import java.nio.ByteBuffer;
  
  import com.alibaba.cobar.mysql.BufferUtil;
  import com.alibaba.cobar.mysql.MySQLMessage;
  import com.alibaba.cobar.net.BackendConnection;
  
  /**
   * From client to server when the client do heartbeat between cobar cluster.
   * 
   * <pre>
   * Bytes         Name
   * -----         ----
   * 1             command
   * n             id
   * 
   * @author haiqing.zhuhq 2012-07-06
   */
  public class HeartbeatPacket extends MySQLPacket {
  
      public byte command;
      public long id;
  
      public void read(byte[] data) {
          MySQLMessage mm = new MySQLMessage(data);
          packetLength = mm.readUB3();
          packetId = mm.read();
          command = mm.read();
          id = mm.readLength();
      }
  
      @Override
      public void write(BackendConnection c) {
          ByteBuffer buffer = c.allocate();
          BufferUtil.writeUB3(buffer, calcPacketSize());
          buffer.put(packetId);
          buffer.put(command);
          BufferUtil.writeLength(buffer, id);
          c.write(buffer);
      }
  
      @Override
      public int calcPacketSize() {
          return 1 + BufferUtil.getLength(id);
      }
  
      @Override
      protected String getPacketInfo() {
          return "Cobar Heartbeat Packet";
      }
  
  }
  