/*
 * 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;

import com.google.common.base.Objects;
import io.netty.buffer.ByteBuf;

import org.apache.spark.network.protocol.Encoders;

// Needed by ScalaDoc. See SPARK-7726
import static org.apache.spark.network.shuffle.protocol.BlockTransferMessage.Type;


/**
 * Request to push a block to a remote shuffle service to be merged in push based shuffle.
 * The remote shuffle service will also include this message when responding the push requests.
 */
public class PushBlockStream extends BlockTransferMessage {
  public final String appId;
  public final String blockId;
  // Similar to the chunkIndex in StreamChunkId, indicating the index of a block in a batch of
  // blocks to be pushed.
  public final int index;

  public PushBlockStream(String appId, String blockId, int index) {
    this.appId = appId;
    this.blockId = blockId;
    this.index = index;
  }

  @Override
  protected Type type() {
    return Type.PUSH_BLOCK_STREAM;
  }

  @Override
  public int hashCode() {
    return Objects.hashCode(appId, blockId, index);
  }

  @Override
  public String toString() {
    return Objects.toStringHelper(this)
      .add("appId", appId)
      .add("blockId", blockId)
      .add("index", index)
      .toString();
  }

  @Override
  public boolean equals(Object other) {
    if (other != null && other instanceof PushBlockStream) {
      PushBlockStream o = (PushBlockStream) other;
      return Objects.equal(appId, o.appId)
        && Objects.equal(blockId, o.blockId)
        && index == o.index;
    }
    return false;
  }

  @Override
  public int encodedLength() {
    return Encoders.Strings.encodedLength(appId)
      + Encoders.Strings.encodedLength(blockId) + 4;
  }

  @Override
  public void encode(ByteBuf buf) {
    Encoders.Strings.encode(buf, appId);
    Encoders.Strings.encode(buf, blockId);
    buf.writeInt(index);
  }

  public static PushBlockStream decode(ByteBuf buf) {
    String appId = Encoders.Strings.decode(buf);
    String blockId = Encoders.Strings.decode(buf);
    int index = buf.readInt();
    return new PushBlockStream(appId, blockId, index);
  }
}
