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