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 org.apache.spark.network.shuffle.protocol.mesos;
  
  import io.netty.buffer.ByteBuf;
  import org.apache.spark.network.protocol.Encoders;
  import org.apache.spark.network.shuffle.protocol.BlockTransferMessage;
  
  // Needed by ScalaDoc. See SPARK-7726
  import static org.apache.spark.network.shuffle.protocol.BlockTransferMessage.Type;
  
  /**
   * A heartbeat sent from the driver to the MesosExternalShuffleService.
   */
  public class ShuffleServiceHeartbeat extends BlockTransferMessage {
    private final String appId;
  
    public ShuffleServiceHeartbeat(String appId) {
      this.appId = appId;
    }
  
    public String getAppId() { return appId; }
  
    @Override
    protected Type type() { return Type.HEARTBEAT; }
  
    @Override
    public int encodedLength() { return Encoders.Strings.encodedLength(appId); }
  
    @Override
    public void encode(ByteBuf buf) {
      Encoders.Strings.encode(buf, appId);
    }
  
    public static ShuffleServiceHeartbeat decode(ByteBuf buf) {
      return new ShuffleServiceHeartbeat(Encoders.Strings.decode(buf));
    }
  }
  