/*

  * 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.examples;

 import org.apache.hadoop.io.LongWritable;

 import org.apache.giraph.graph.Aggregator;

 /**

  * Aggregator for summing up values.

  */

 public class LongSumAggregator implements Aggregator<LongWritable> {

   /** Internal sum */

   private long sum = 0;

   /**

    * Aggregate with a primitive long.

    *

    * @param value Long value to aggregate.

    */

   public void aggregate(long value) {

     sum += value;

   }

   @Override

   public void aggregate(LongWritable value) {

     sum += value.get();

   }

   @Override

   public void setAggregatedValue(LongWritable value) {

     sum = value.get();

   }

   @Override

   public LongWritable getAggregatedValue() {

     return new LongWritable(sum);

   }

   @Override

   public LongWritable createAggregatedValue() {

     return new LongWritable();

   }

 }