org.apache.hadoop.fs.statistics.impl.PairedDurationTrackerFactory Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
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*/
package org.apache.hadoop.fs.statistics.impl;
import java.time.Duration;
import org.apache.hadoop.fs.statistics.DurationTracker;
import org.apache.hadoop.fs.statistics.DurationTrackerFactory;
/**
* A duration tracker factory which aggregates two other trackers
* to have the same lifecycle.
*
* This is to ease having instance-level tracking alongside global
* values, such as an input stream and a filesystem.
*
* It's got some inefficiencies -assuming system time is used for
* the tracking, System.currentTimeMillis will be invoked twice
* at each point of the process -and the results may actually be different.
* However, it enables multiple duration tracker factories to be given the
* opportunity to collect the statistics.
*/
final class PairedDurationTrackerFactory implements DurationTrackerFactory {
private final DurationTrackerFactory local;
private final DurationTrackerFactory global;
PairedDurationTrackerFactory(final DurationTrackerFactory local,
final DurationTrackerFactory global) {
this.local = local;
this.global = global;
}
@Override
public DurationTracker trackDuration(final String key, final long count) {
return new PairedDurationTracker(
global.trackDuration(key, count),
local.trackDuration(key, count));
}
/**
* Tracker which wraps the two duration trackers created for the operation.
*/
private static final class PairedDurationTracker
implements DurationTracker {
private final DurationTracker firstDuration;
private final DurationTracker secondDuration;
private PairedDurationTracker(
final DurationTracker firstDuration,
final DurationTracker secondDuration) {
this.firstDuration = firstDuration;
this.secondDuration = secondDuration;
}
@Override
public void failed() {
firstDuration.failed();
secondDuration.failed();
}
@Override
public void close() {
firstDuration.close();
secondDuration.close();
}
/**
* @return the global duration
*/
@Override
public Duration asDuration() {
return firstDuration.asDuration();
}
}
}