/*

  * 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.aggregators;

 import org.apache.hadoop.io.Writable;

 /**

  * Abstract class for {@link Aggregator}.

  * Implements get value, set value and reset methods and has internal value

  * object.

  *

  * @param <A> Aggregated value

  */

 public abstract class BasicAggregator<A extends Writable> implements

     Aggregator<A> {

   /** Internal value */

   private A value;

   /**

    * Default constructor.

    * Creates new value object and resets the aggregator

    */

   public BasicAggregator() {

     value = createInitialValue();

   }

   /**

    * Constructor

    * @param initialValue initial value

    */

   public BasicAggregator(A initialValue) {

     value = initialValue;

   }

   @Override

   public A getAggregatedValue() {

     return value;

   }

   @Override

   public void setAggregatedValue(A value) {

     this.value = value;

   }

   @Override

   public void reset() {

     value = createInitialValue();

   }

 }