org.apache.flink.streaming.runtime.partitioner.KeyGroupStreamPartitioner Maven / Gradle / Ivy
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.streaming.runtime.partitioner;
import org.apache.flink.annotation.Internal;
import org.apache.flink.api.java.functions.KeySelector;
import org.apache.flink.runtime.plugable.SerializationDelegate;
import org.apache.flink.runtime.state.KeyGroupRangeAssignment;
import org.apache.flink.streaming.runtime.streamrecord.StreamRecord;
import org.apache.flink.util.Preconditions;
/**
* Partitioner selects the target channel based on the key group index.
*
* @param Type of the elements in the Stream being partitioned
*/
@Internal
public class KeyGroupStreamPartitioner extends StreamPartitioner implements ConfigurableStreamPartitioner {
private static final long serialVersionUID = 1L;
private final int[] returnArray = new int[1];
private final KeySelector keySelector;
private int maxParallelism;
public KeyGroupStreamPartitioner(KeySelector keySelector, int maxParallelism) {
Preconditions.checkArgument(maxParallelism > 0, "Number of key-groups must be > 0!");
this.keySelector = Preconditions.checkNotNull(keySelector);
this.maxParallelism = maxParallelism;
}
public int getMaxParallelism() {
return maxParallelism;
}
@Override
public int[] selectChannels(
SerializationDelegate> record,
int numberOfOutputChannels) {
K key;
try {
key = keySelector.getKey(record.getInstance().getValue());
} catch (Exception e) {
throw new RuntimeException("Could not extract key from " + record.getInstance().getValue(), e);
}
returnArray[0] = KeyGroupRangeAssignment.assignKeyToParallelOperator(key, maxParallelism, numberOfOutputChannels);
return returnArray;
}
@Override
public StreamPartitioner copy() {
return this;
}
@Override
public String toString() {
return "HASH";
}
@Override
public void configure(int maxParallelism) {
KeyGroupRangeAssignment.checkParallelismPreconditions(maxParallelism);
this.maxParallelism = maxParallelism;
}
}