/*

  * 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.block_app.reducers.collect;

 import java.util.ArrayList;

 import java.util.List;

 import org.apache.giraph.block_app.framework.api.CreateReducersApi;

 import org.apache.giraph.block_app.framework.piece.global_comm.BroadcastHandle;

 import org.apache.giraph.block_app.framework.piece.global_comm.array.BroadcastArrayHandle;

 import org.apache.giraph.master.MasterGlobalCommUsage;

 import org.apache.giraph.reducers.ReduceOperation;

 import org.apache.giraph.worker.WorkerBroadcastUsage;

 import org.apache.giraph.writable.kryo.KryoWritableWrapper;

 /**

  * ShardedReducerHandle where we keep a list of reduced values

  *

  * @param <S> Single value type

  */

 public class CollectShardedReducerHandle<S>

     extends ShardedReducerHandle<S, List<S>> {

   public CollectShardedReducerHandle(CreateReducersApi reduceApi) {

     register(reduceApi);

   }

   @Override

   public ReduceOperation<S, KryoWritableWrapper<List<S>>>

   createReduceOperation() {

     return new CollectReduceOperation<>();

   }

   @Override

   public List<S> createReduceResult(MasterGlobalCommUsage master) {

     int size = 0;

     for (int i = 0; i < REDUCER_COUNT; i++) {

       size += reducers.get(i).getReducedValue(master).get().size();

     }

     return createList(size);

   }

   public List<S> createList(int size) {

     return new ArrayList<S>(size);

   }

   @Override

   public BroadcastHandle<List<S>> createBroadcastHandle(

       BroadcastArrayHandle<KryoWritableWrapper<List<S>>> broadcasts) {

     return new CollectShardedBroadcastHandle(broadcasts);

   }

   /**

    * BroadcastHandle for CollectShardedReducerHandle

    */

   public class CollectShardedBroadcastHandle extends ShardedBroadcastHandle {

     public CollectShardedBroadcastHandle(

         BroadcastArrayHandle<KryoWritableWrapper<List<S>>> broadcasts) {

       super(broadcasts);

     }

     @Override

     public List<S> createBroadcastResult(WorkerBroadcastUsage worker) {

       int size = 0;

       for (int i = 0; i < REDUCER_COUNT; i++) {

         size += broadcasts.get(i).getBroadcast(worker).get().size();

       }

       return createList(size);

     }

   }

 }