org.apache.hadoop.fs.statistics.DurationTrackerFactory Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
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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.hadoop.fs.statistics;
import static org.apache.hadoop.fs.statistics.IOStatisticsSupport.stubDurationTracker;
/**
* Interface for a source of duration tracking.
*
* This is intended for uses where it can be passed into classes
* which update operation durations, without tying those
* classes to internal implementation details.
*/
public interface DurationTrackerFactory {
/**
* Initiate a duration tracking operation by creating/returning
* an object whose {@code close()} call will
* update the statistics.
*
* The statistics counter with the key name will be incremented
* by the given count.
*
* The expected use is within a try-with-resources clause.
*
* The default implementation returns a stub duration tracker.
* @param key statistic key prefix
* @param count #of times to increment the matching counter in this
* operation.
* @return an object to close after an operation completes.
*/
default DurationTracker trackDuration(String key, long count) {
return stubDurationTracker();
}
/**
* Initiate a duration tracking operation by creating/returning
* an object whose {@code close()} call will
* update the statistics.
* The expected use is within a try-with-resources clause.
* @param key statistic key
* @return an object to close after an operation completes.
*/
default DurationTracker trackDuration(String key) {
return trackDuration(key, 1);
}
}