/*
* 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.flink.api.java.operators.translation;
import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.functions.ReduceFunction;
import org.apache.flink.api.common.operators.UnaryOperatorInformation;
import org.apache.flink.api.common.operators.base.ReduceOperatorBase;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.common.operators.Keys;
import org.apache.flink.api.java.tuple.Tuple2;
/**
* A reduce operator that takes 2-tuples (key-value pairs), and applies the reduce operation only
* on the unwrapped values.
*/
@Internal
public class PlanUnwrappingReduceOperator<T, K> extends ReduceOperatorBase<Tuple2<K, T>, ReduceFunction<Tuple2<K, T>>> {
public PlanUnwrappingReduceOperator(ReduceFunction<T> udf, Keys.SelectorFunctionKeys<T, K> key, String name,
TypeInformation<T> type, TypeInformation<Tuple2<K, T>> typeInfoWithKey)
{
super(new ReduceWrapper<T, K>(udf), new UnaryOperatorInformation<Tuple2<K, T>, Tuple2<K, T>>(typeInfoWithKey, typeInfoWithKey), key.computeLogicalKeyPositions(), name);
}
public static final class ReduceWrapper<T, K> extends WrappingFunction<ReduceFunction<T>>
implements ReduceFunction<Tuple2<K, T>>
{
private static final long serialVersionUID = 1L;
private ReduceWrapper(ReduceFunction<T> wrapped) {
super(wrapped);
}
@Override
public Tuple2<K, T> reduce(Tuple2<K, T> value1, Tuple2<K, T> value2) throws Exception {
value1.f1 = this.wrappedFunction.reduce(value1.f1, value2.f1);
return value1;
}
}
}