/*

  * 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.giraph.comm.requests;

 import org.apache.giraph.utils.VertexIdData;

 import org.apache.giraph.utils.PairList;

 import org.apache.hadoop.io.WritableComparable;

 import org.apache.log4j.Logger;

 import java.io.DataInput;

 import java.io.DataOutput;

 import java.io.IOException;

 /**

  * Abstract request to send a collection of data, indexed by vertex id,

  * for a partition.

  *

  * @param <I> Vertex id

  * @param <T> Data

  * @param <B> Specialization of

  * {@link org.apache.giraph.utils.VertexIdData} for T

  */

 @SuppressWarnings("unchecked")

 public abstract class SendWorkerDataRequest<I extends WritableComparable, T,

     B extends VertexIdData<I, T>>

     extends WritableRequest implements WorkerRequest {

   /** Class logger */

   private static final Logger LOG =

       Logger.getLogger(SendWorkerDataRequest.class);

   /**

    * All data for a group of vertices, organized by partition, which

    * are owned by a single (destination) worker. This data is all

    * destined for this worker.

    * */

   protected PairList<Integer, B> partitionVertexData;

   /**

    * Constructor used for reflection only

    */

   public SendWorkerDataRequest() { }

   /**

    * Constructor used to send request.

    *

    * @param partVertData Map of remote partitions => VertexIdData

    */

   public SendWorkerDataRequest(

       PairList<Integer, B> partVertData) {

     this.partitionVertexData = partVertData;

   }

   /**

    * Create a new {@link org.apache.giraph.utils.VertexIdData}

    * specialized for the use case.

    *

    * @return A new instance of

    * {@link org.apache.giraph.utils.VertexIdData}

    */

   public abstract B createVertexIdData();

   @Override

   public void readFieldsRequest(DataInput input) throws IOException {

     int numPartitions = input.readInt();

     partitionVertexData = new PairList<Integer, B>();

     partitionVertexData.initialize(numPartitions);

     while (numPartitions-- > 0) {

       final int partitionId = input.readInt();

       B vertexIdData = createVertexIdData();

       vertexIdData.setConf(getConf());

       vertexIdData.readFields(input);

       partitionVertexData.add(partitionId, vertexIdData);

     }

   }

   @Override

   public void writeRequest(DataOutput output) throws IOException {

     output.writeInt(partitionVertexData.getSize());

     PairList<Integer, B>.Iterator

         iterator = partitionVertexData.getIterator();

     while (iterator.hasNext()) {

       iterator.next();

       output.writeInt(iterator.getCurrentFirst());

       iterator.getCurrentSecond().write(output);

     }

   }

   @Override

   public int getSerializedSize() {

     int size = super.getSerializedSize() + 4;

     PairList<Integer, B>.Iterator iterator = partitionVertexData.getIterator();

     while (iterator.hasNext()) {

       iterator.next();

       size += 4 + iterator.getCurrentSecond().getSerializedSize();

     }

     return size;

   }

 }