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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,
* 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.hadoop.fs.statistics.impl;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.fs.statistics.IOStatistics;
import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
import org.apache.hadoop.fs.statistics.IOStatisticsContext;
import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
/**
* Implementing the IOStatisticsContext.
*
* A Context defined for IOStatistics collection per thread which captures
* each worker thread's work in FS streams and stores it in the form of
* IOStatisticsSnapshot.
*
* For the current thread the IOStatisticsSnapshot can be used as a way to
* move the IOStatistics data between applications using the Serializable
* nature of the class.
*/
public final class IOStatisticsContextImpl implements IOStatisticsContext {
private static final Logger LOG =
LoggerFactory.getLogger(IOStatisticsContextImpl.class);
/**
* Thread ID.
*/
private final long threadId;
/**
* Unique ID.
*/
private final long id;
/**
* IOStatistics to aggregate.
*/
private final IOStatisticsSnapshot ioStatistics = new IOStatisticsSnapshot();
/**
* Constructor.
* @param threadId thread ID
* @param id instance ID.
*/
public IOStatisticsContextImpl(final long threadId, final long id) {
this.threadId = threadId;
this.id = id;
}
@Override
public String toString() {
return "IOStatisticsContextImpl{" +
"id=" + id +
", threadId=" + threadId +
", ioStatistics=" + ioStatistics +
'}';
}
/**
* Get the IOStatisticsAggregator of the context.
* @return the instance of IOStatisticsAggregator for this context.
*/
@Override
public IOStatisticsAggregator getAggregator() {
return ioStatistics;
}
/**
* Returns a snapshot of the current thread's IOStatistics.
*
* @return IOStatisticsSnapshot of the context.
*/
@Override
public IOStatisticsSnapshot snapshot() {
LOG.debug("Taking snapshot of IOStatisticsContext id {}", id);
return new IOStatisticsSnapshot(ioStatistics);
}
/**
* Reset the thread +.
*/
@Override
public void reset() {
LOG.debug("clearing IOStatisticsContext id {}", id);
ioStatistics.clear();
}
@Override
public IOStatistics getIOStatistics() {
return ioStatistics;
}
/**
* ID of this context.
* @return ID.
*/
@Override
public long getID() {
return id;
}
/**
* Get the thread ID.
* @return thread ID.
*/
public long getThreadID() {
return threadId;
}
}