/*
* 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.aggregation.impl;
import com.hazelcast.mapreduce.Collator;
import com.hazelcast.mapreduce.Combiner;
import com.hazelcast.mapreduce.CombinerFactory;
import com.hazelcast.mapreduce.Mapper;
import com.hazelcast.mapreduce.Reducer;
import com.hazelcast.mapreduce.ReducerFactory;
import com.hazelcast.mapreduce.aggregation.Supplier;
import java.math.BigInteger;
import java.util.Map;
/**
* The predefined minimum aggregation for values of type {@link java.math.BigInteger}.
*
* @param <Key> the input key type
* @param <Value> the input value type
*/
public class BigIntegerMinAggregation<Key, Value>
implements AggType<Key, Value, Key, BigInteger, BigInteger, BigInteger, BigInteger> {
@Override
public Collator<Map.Entry<Key, BigInteger>, BigInteger> getCollator() {
return new Collator<Map.Entry<Key, BigInteger>, BigInteger>() {
@Override
public BigInteger collate(Iterable<Map.Entry<Key, BigInteger>> values) {
BigInteger min = null;
for (Map.Entry<Key, BigInteger> entry : values) {
BigInteger value = entry.getValue();
min = min == null ? value : value.min(min);
}
return min;
}
};
}
@Override
public Mapper<Key, Value, Key, BigInteger> getMapper(Supplier<Key, Value, BigInteger> supplier) {
return new SupplierConsumingMapper<Key, Value, BigInteger>(supplier);
}
@Override
public CombinerFactory<Key, BigInteger, BigInteger> getCombinerFactory() {
return new BigIntegerMinCombinerFactory<Key>();
}
@Override
public ReducerFactory<Key, BigInteger, BigInteger> getReducerFactory() {
return new BigIntegerMinReducerFactory<Key>();
}
/**
* Minimum CombinerFactory for type {@link java.math.BigInteger}
*
* @param <Key> the key type
*/
static final class BigIntegerMinCombinerFactory<Key>
extends AbstractAggregationCombinerFactory<Key, BigInteger, BigInteger> {
@Override
public Combiner<BigInteger, BigInteger> newCombiner(Key key) {
return new BigIntegerMinCombiner();
}
@Override
public int getId() {
return AggregationsDataSerializerHook.BIG_INTEGER_MIN_COMBINER_FACTORY;
}
}
/**
* Minimum ReducerFactory for type {@link java.math.BigInteger}
*
* @param <Key> the key type
*/
static final class BigIntegerMinReducerFactory<Key>
extends AbstractAggregationReducerFactory<Key, BigInteger, BigInteger> {
@Override
public Reducer<BigInteger, BigInteger> newReducer(Key key) {
return new BigIntegerMinReducer();
}
@Override
public int getId() {
return AggregationsDataSerializerHook.BIG_INTEGER_MIN_REDUCER_FACTORY;
}
}
/**
* Minimum Combiner for type {@link java.math.BigInteger}
*/
private static final class BigIntegerMinCombiner
extends Combiner<BigInteger, BigInteger> {
private BigInteger min;
@Override
public void combine(BigInteger value) {
min = min == null ? value : value.min(min);
}
@Override
public BigInteger finalizeChunk() {
return min;
}
@Override
public void reset() {
min = null;
}
}
/**
* Minimum Reducer for type {@link java.math.BigInteger}
*/
private static final class BigIntegerMinReducer
extends Reducer<BigInteger, BigInteger> {
private volatile BigInteger min;
@Override
public void reduce(BigInteger value) {
min = min == null ? value : value.min(min);
}
@Override
public BigInteger finalizeReduce() {
return min;
}
}
}