org.apache.flink.runtime.io.network.partition.external.LocalityBasedSubpartitionViewScheduler Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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
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*/
package org.apache.flink.runtime.io.network.partition.external;
import org.apache.flink.annotation.VisibleForTesting;
import java.util.Comparator;
import java.util.PriorityQueue;
/**
* An implementation of {@link ExternalBlockSubpartitionViewScheduler} which schedules
* {@link ExternalBlockSubpartitionView}s according to the location of blocks to read on disks.
*/
public class LocalityBasedSubpartitionViewScheduler implements ExternalBlockSubpartitionViewScheduler {
@VisibleForTesting
protected final PriorityQueue subpartitionViewQueue;
public LocalityBasedSubpartitionViewScheduler() {
this.subpartitionViewQueue = new PriorityQueue<>(new LocalityBasedSubpartitionViewComparator());
}
@Override
public void addToSchedule(ExternalBlockSubpartitionView subpartitionView) {
subpartitionViewQueue.offer(subpartitionView);
}
@Override
public ExternalBlockSubpartitionView schedule() {
return subpartitionViewQueue.poll();
}
/**
* Compares subpartition views based on their relative locality.
*/
private static class LocalityBasedSubpartitionViewComparator implements Comparator {
@Override
public int compare(ExternalBlockSubpartitionView o1, ExternalBlockSubpartitionView o2) {
if (!o1.getResultPartitionDir().equals(o2.getResultPartitionDir())) {
return o1.getResultPartitionDir().compareTo(o2.getResultPartitionDir());
}
return o1.getSubpartitionIndex() - o2.getSubpartitionIndex();
}
}
}