/*

  * 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.netty;

 import java.io.IOException;

 import org.apache.giraph.bsp.CentralizedServiceWorker;

 import org.apache.giraph.comm.GlobalCommType;

 import org.apache.giraph.comm.WorkerClient;

 import org.apache.giraph.comm.aggregators.AggregatorUtils;

 import org.apache.giraph.comm.aggregators.SendGlobalCommCache;

 import org.apache.giraph.comm.aggregators.WorkerAggregatorRequestProcessor;

 import org.apache.giraph.comm.requests.SendAggregatorsToWorkerRequest;

 import org.apache.giraph.comm.requests.SendReducedToMasterRequest;

 import org.apache.giraph.comm.requests.SendWorkerAggregatorsRequest;

 import org.apache.giraph.conf.ImmutableClassesGiraphConfiguration;

 import org.apache.giraph.worker.WorkerInfo;

 import org.apache.hadoop.io.Writable;

 import org.apache.hadoop.util.Progressable;

 /**

  * Netty implementation of {@link WorkerAggregatorRequestProcessor}

  */

 public class NettyWorkerAggregatorRequestProcessor

     implements WorkerAggregatorRequestProcessor {

   /** Progressable used to report progress */

   private final Progressable progressable;

   /** NettyClient that could be shared among one or more instances */

   private final WorkerClient<?, ?, ?> workerClient;

   /** Service worker */

   private final CentralizedServiceWorker<?, ?, ?> serviceWorker;

   /** Cached map of partition ids to serialized aggregator data */

   private final SendGlobalCommCache sendReducedValuesCache =

       new SendGlobalCommCache(false);

   /** How big a single aggregator request can be */

   private final int maxBytesPerAggregatorRequest;

   /**

    * Constructor.

    *

    * @param progressable  Progressable used to report progress

    * @param configuration Configuration

    * @param serviceWorker Service worker

    */

   public NettyWorkerAggregatorRequestProcessor(

       Progressable progressable,

       ImmutableClassesGiraphConfiguration<?, ?, ?> configuration,

       CentralizedServiceWorker<?, ?, ?> serviceWorker) {

     this.serviceWorker = serviceWorker;

     this.workerClient = serviceWorker.getWorkerClient();

     this.progressable = progressable;

     maxBytesPerAggregatorRequest = configuration.getInt(

         AggregatorUtils.MAX_BYTES_PER_AGGREGATOR_REQUEST,

         AggregatorUtils.MAX_BYTES_PER_AGGREGATOR_REQUEST_DEFAULT);

   }

   @Override

   public boolean sendReducedValue(String name,

       Writable reducedValue) throws IOException {

     WorkerInfo owner =

         AggregatorUtils.getOwner(name,

             serviceWorker.getWorkerInfoList());

     if (isThisWorker(owner)) {

       return false;

     } else {

       int currentSize = sendReducedValuesCache.addValue(owner.getTaskId(),

           name, GlobalCommType.REDUCED_VALUE, reducedValue);

       if (currentSize >= maxBytesPerAggregatorRequest) {

         flushAggregatorsToWorker(owner);

       }

       return true;

     }

   }

   @Override

   public void flush() throws IOException {

     for (WorkerInfo workerInfo : serviceWorker.getWorkerInfoList()) {

       if (!isThisWorker(workerInfo)) {

         sendReducedValuesCache.addSpecialCount(workerInfo.getTaskId());

         flushAggregatorsToWorker(workerInfo);

         progressable.progress();

       }

     }

     sendReducedValuesCache.reset();

   }

   /**

    * Send aggregators from cache to worker.

    *

    * @param worker Worker which we want to send aggregators to

    */

   private void flushAggregatorsToWorker(WorkerInfo worker) {

     byte[] data =

         sendReducedValuesCache.removeSerialized(worker.getTaskId());

     workerClient.sendWritableRequest(worker.getTaskId(),

         new SendWorkerAggregatorsRequest(data,

             serviceWorker.getWorkerInfo().getTaskId()));

   }

   @Override

   public void sendReducedValuesToMaster(byte[] data) throws IOException {

     workerClient.sendWritableRequest(serviceWorker.getMasterInfo().getTaskId(),

         new SendReducedToMasterRequest(data));

   }

   @Override

   public void distributeReducedValues(

       Iterable<byte[]> aggregatorDataList) throws IOException {

     for (byte[] aggregatorData : aggregatorDataList) {

       for (WorkerInfo worker : serviceWorker.getWorkerInfoList()) {

         if (!isThisWorker(worker)) {

           SendAggregatorsToWorkerRequest request =

               new SendAggregatorsToWorkerRequest(aggregatorData,

                   serviceWorker.getWorkerInfo().getTaskId());

           workerClient.sendWritableRequest(worker.getTaskId(), request);

         }

         progressable.progress();

       }

     }

   }

   /**

    * Check if workerInfo describes current worker.

    *

    * @param workerInfo Worker to check

    * @return True iff workerInfo corresponds to current worker.

    */

   private boolean isThisWorker(WorkerInfo workerInfo) {

     return serviceWorker.getWorkerInfo().getTaskId() == workerInfo.getTaskId();

   }

 }