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.protocol;
  
  import com.google.common.base.Objects;
  import io.netty.buffer.ByteBuf;
  
  import org.apache.spark.network.buffer.ManagedBuffer;
  import org.apache.spark.network.buffer.NettyManagedBuffer;
  
  /**
   * Response to {@link ChunkFetchRequest} when a chunk exists and has been successfully fetched.
   *
   * Note that the server-side encoding of this messages does NOT include the buffer itself, as this
   * may be written by Netty in a more efficient manner (i.e., zero-copy write).
   * Similarly, the client-side decoding will reuse the Netty ByteBuf as the buffer.
   */
  public final class ChunkFetchSuccess extends AbstractResponseMessage {
    public final StreamChunkId streamChunkId;
  
    public ChunkFetchSuccess(StreamChunkId streamChunkId, ManagedBuffer buffer) {
      super(buffer, true);
      this.streamChunkId = streamChunkId;
    }
  
    @Override
    public Type type() { return Type.ChunkFetchSuccess; }
  
    @Override
    public int encodedLength() {
      return streamChunkId.encodedLength();
    }
  
    /** Encoding does NOT include 'buffer' itself. See {@link MessageEncoder}. */
    @Override
    public void encode(ByteBuf buf) {
      streamChunkId.encode(buf);
    }
  
    @Override
    public ResponseMessage createFailureResponse(String error) {
      return new ChunkFetchFailure(streamChunkId, error);
    }
  
    /** Decoding uses the given ByteBuf as our data, and will retain() it. */
    public static ChunkFetchSuccess decode(ByteBuf buf) {
      StreamChunkId streamChunkId = StreamChunkId.decode(buf);
      buf.retain();
      NettyManagedBuffer managedBuf = new NettyManagedBuffer(buf.duplicate());
      return new ChunkFetchSuccess(streamChunkId, managedBuf);
    }
  
    @Override
    public int hashCode() {
      return Objects.hashCode(streamChunkId, body());
    }
  
    @Override
    public boolean equals(Object other) {
      if (other instanceof ChunkFetchSuccess) {
        ChunkFetchSuccess o = (ChunkFetchSuccess) other;
        return streamChunkId.equals(o.streamChunkId) && super.equals(o);
      }
      return false;
    }
  
    @Override
    public String toString() {
      return Objects.toStringHelper(this)
        .add("streamChunkId", streamChunkId)
        .add("buffer", body())
        .toString();
    }
  }
  