/*

  * 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.reducers.impl.KryoWrappedReduceOperation;

 /**

  * Collect values reduce operation

  *

  * @param <S> Type of values to collect

  */

 public class CollectReduceOperation<S>

     extends KryoWrappedReduceOperation<S, List<S>> {

   @Override

   public List<S> createValue() {

     return createList();

   }

   @Override

   public void reduce(List<S> reduceInto, S value) {

     reduceInto.add(value);

   }

   @Override

   public void reduceMerge(List<S> reduceInto, List<S> toReduce) {

     reduceInto.addAll(toReduce);

   }

   public List<S> createList() {

     return new ArrayList<>();

   }

 }