/*
* 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.streaming.api.transformations;
import com.google.common.collect.Lists;
import java.util.Collection;
import java.util.List;
import org.apache.flink.annotation.Internal;
import org.apache.flink.streaming.api.operators.ChainingStrategy;
import org.apache.flink.streaming.runtime.partitioner.StreamPartitioner;
/**
* This transformation represents a change of partitioning of the input elements.
*
* <p>This does not create a physical operation, it only affects how upstream operations are
* connected to downstream operations.
*
* @param <T> The type of the elements that result from this {@code PartitionTransformation}
*/
@Internal
public class PartitionTransformation<T> extends StreamTransformation<T> {
private final StreamTransformation<T> input;
private final StreamPartitioner<T> partitioner;
/**
* Creates a new {@code PartitionTransformation} from the given input and
* {@link StreamPartitioner}.
*
* @param input The input {@code StreamTransformation}
* @param partitioner The {@code StreamPartitioner}
*/
public PartitionTransformation(StreamTransformation<T> input, StreamPartitioner<T> partitioner) {
super("Partition", input.getOutputType(), input.getParallelism());
this.input = input;
this.partitioner = partitioner;
}
/**
* Returns the input {@code StreamTransformation} of this {@code SinkTransformation}.
*/
public StreamTransformation<T> getInput() {
return input;
}
/**
* Returns the {@code StreamPartitioner} that must be used for partitioning the elements
* of the input {@code StreamTransformation}.
*/
public StreamPartitioner<T> getPartitioner() {
return partitioner;
}
@Override
public Collection<StreamTransformation<?>> getTransitivePredecessors() {
List<StreamTransformation<?>> result = Lists.newArrayList();
result.add(this);
result.addAll(input.getTransitivePredecessors());
return result;
}
@Override
public final void setChainingStrategy(ChainingStrategy strategy) {
throw new UnsupportedOperationException("Cannot set chaining strategy on Union Transformation.");
}
}