com.hazelcast.mapreduce.CombinerFactory Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2013, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.mapreduce;
import com.hazelcast.spi.annotation.Beta;
import java.io.Serializable;
/**
*
* A CombinerFactory implementation is used to build {@link Combiner} instances per key.
* An implementation needs to be serializable by Hazelcast since it is distributed together with
* the {@link Mapper} implementation to run alongside.
*
*
* @param key type of the resulting keys
* @param value type of the incoming values
* @param value type of the reduced values
* @since 3.2
*/
@Beta
public interface CombinerFactory
extends Serializable {
/**
* Build a new {@link Combiner} instance specific to the supplied key.
*
* @param key key the Combiner is build for
* @return a Combiner instance specific for the given key
*/
Combiner newCombiner(KeyIn key);
}