/*

  * 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;

 import org.apache.giraph.bsp.CentralizedServiceWorker;

 import org.apache.giraph.conf.ImmutableClassesGiraphConfiguration;

 import org.apache.giraph.graph.Vertex;

 import org.apache.giraph.partition.PartitionOwner;

 import org.apache.giraph.utils.ExtendedDataOutput;

 import org.apache.giraph.utils.WritableUtils;

 import org.apache.hadoop.io.Writable;

 import org.apache.hadoop.io.WritableComparable;

 import org.apache.log4j.Logger;

 import java.io.IOException;

 import static org.apache.giraph.conf.GiraphConstants.ADDITIONAL_VERTEX_REQUEST_SIZE;

 import static org.apache.giraph.conf.GiraphConstants.MAX_VERTEX_REQUEST_SIZE;

 /**

  * Caches partition vertices prior to sending.  Aggregating these requests

  * will make larger, more efficient requests.  Not thread-safe.

  *

  * @param <I> Vertex index value

  * @param <V> Vertex value

  * @param <E> Edge value

  */

 public class SendPartitionCache<I extends WritableComparable,

     V extends Writable, E extends Writable> extends

     SendDataCache<ExtendedDataOutput> {

   /** Class logger */

   private static final Logger LOG =

       Logger.getLogger(SendPartitionCache.class);

   /**

    * Constructor.

    *

    * @param conf Giraph configuration

    * @param serviceWorker Service worker

    */

   public SendPartitionCache(ImmutableClassesGiraphConfiguration<I, V, E> conf,

                             CentralizedServiceWorker<?, ?, ?> serviceWorker) {

     super(conf, serviceWorker, MAX_VERTEX_REQUEST_SIZE.get(conf),

         ADDITIONAL_VERTEX_REQUEST_SIZE.get(conf));

   }

   /**

    * Add a vertex to the cache.

    *

    * @param partitionOwner Partition owner of the vertex

    * @param vertex Vertex to add

    * @return Size of partitions for this worker

    */

   public int addVertex(PartitionOwner partitionOwner,

       Vertex<I, V, E> vertex) {

     // Get the data collection

     ExtendedDataOutput partitionData =

         getData(partitionOwner.getPartitionId());

     int taskId = partitionOwner.getWorkerInfo().getTaskId();

     int originalSize = 0;

     if (partitionData == null) {

       partitionData = getConf().createExtendedDataOutput(

           getInitialBufferSize(taskId));

       setData(partitionOwner.getPartitionId(), partitionData);

     } else {

       originalSize = partitionData.getPos();

     }

     try {

       WritableUtils.<I, V, E>writeVertexToDataOutput(

           partitionData, vertex, getConf());

     } catch (IOException e) {

       throw new IllegalStateException("addVertex: Failed to serialize", e);

     }

     // Update the size of cached, outgoing data per worker

     return incrDataSize(taskId, partitionData.getPos() - originalSize);

   }

 }