| /* |
| * 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.combiner; |
| |
| import org.apache.giraph.types.ops.DoubleTypeOps; |
| import org.apache.giraph.types.ops.FloatTypeOps; |
| import org.apache.giraph.types.ops.IntTypeOps; |
| import org.apache.giraph.types.ops.LongTypeOps; |
| import org.apache.giraph.types.ops.NumericTypeOps; |
| import org.apache.hadoop.io.DoubleWritable; |
| import org.apache.hadoop.io.FloatWritable; |
| import org.apache.hadoop.io.IntWritable; |
| import org.apache.hadoop.io.LongWritable; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.io.WritableComparable; |
| |
| /** |
| * Message combiner which sums all messages. |
| * |
| * @param <M> Message type |
| */ |
| public class SumMessageCombiner<M extends Writable> |
| implements MessageCombiner<WritableComparable, M> { |
| /** DoubleWritable specialization */ |
| public static final SumMessageCombiner<DoubleWritable> DOUBLE = |
| new SumMessageCombiner<>(DoubleTypeOps.INSTANCE); |
| /** DoubleWritable specialization */ |
| public static final SumMessageCombiner<FloatWritable> FLOAT = |
| new SumMessageCombiner<>(FloatTypeOps.INSTANCE); |
| /** LongWritable specialization */ |
| public static final SumMessageCombiner<LongWritable> LONG = |
| new SumMessageCombiner<>(LongTypeOps.INSTANCE); |
| /** IntWritable specialization */ |
| public static final SumMessageCombiner<IntWritable> INT = |
| new SumMessageCombiner<>(IntTypeOps.INSTANCE); |
| |
| /** Value type operations */ |
| private final NumericTypeOps<M> typeOps; |
| |
| /** |
| * Constructor |
| * @param typeOps Value type operations |
| */ |
| public SumMessageCombiner(NumericTypeOps<M> typeOps) { |
| this.typeOps = typeOps; |
| } |
| |
| @Override |
| public void combine( |
| WritableComparable vertexIndex, M originalMessage, M messageToCombine) { |
| typeOps.plusInto(originalMessage, messageToCombine); |
| } |
| |
| @Override |
| public M createInitialMessage() { |
| return typeOps.createZero(); |
| } |
| } |