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RocksDB fat jar that contains .so files for linux64, jnilib files
for Mac OSX, and a .dll for Windows x64. It contains the Yamcs merge operator for the Parameter Archive
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
package org.rocksdb;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.TimeUnit;
/**
* Helper class to collect DB statistics periodically at a period specified in
* constructor. Callback function (provided in constructor) is called with
* every statistics collection.
*
* Caller should call start() to start statistics collection. Shutdown() should
* be called to stop stats collection and should be called before statistics (
* provided in constructor) reference has been disposed.
*/
public class StatisticsCollector {
private final List _statsCollectorInputList;
private final ExecutorService _executorService;
private final int _statsCollectionInterval;
private volatile boolean _isRunning = true;
/**
* Constructor for statistics collector.
*
* @param statsCollectorInputList List of statistics collector input.
* @param statsCollectionIntervalInMilliSeconds Statistics collection time
* period (specified in milliseconds).
*/
public StatisticsCollector(
final List statsCollectorInputList,
final int statsCollectionIntervalInMilliSeconds) {
_statsCollectorInputList = statsCollectorInputList;
_statsCollectionInterval = statsCollectionIntervalInMilliSeconds;
_executorService = Executors.newSingleThreadExecutor();
}
public void start() {
_executorService.submit(collectStatistics());
}
/**
* Shuts down statistics collector.
*
* @param shutdownTimeout Time in milli-seconds to wait for shutdown before
* killing the collection process.
* @throws java.lang.InterruptedException thrown if Threads are interrupted.
*/
public void shutDown(final int shutdownTimeout) throws InterruptedException {
_isRunning = false;
_executorService.shutdownNow();
// Wait for collectStatistics runnable to finish so that disposal of
// statistics does not cause any exceptions to be thrown.
_executorService.awaitTermination(shutdownTimeout, TimeUnit.MILLISECONDS);
}
@SuppressWarnings("PMD.CloseResource")
private Runnable collectStatistics() {
return () -> {
while (_isRunning) {
try {
if (Thread.currentThread().isInterrupted()) {
break;
}
for (final StatsCollectorInput statsCollectorInput : _statsCollectorInputList) {
final Statistics statistics = statsCollectorInput.getStatistics();
final StatisticsCollectorCallback statsCallback = statsCollectorInput.getCallback();
// Collect ticker data
for (final TickerType ticker : TickerType.values()) {
if (ticker != TickerType.TICKER_ENUM_MAX) {
final long tickerValue = statistics.getTickerCount(ticker);
statsCallback.tickerCallback(ticker, tickerValue);
}
}
// Collect histogram data
for (final HistogramType histogramType : HistogramType.values()) {
if (histogramType != HistogramType.HISTOGRAM_ENUM_MAX) {
final HistogramData histogramData = statistics.getHistogramData(histogramType);
statsCallback.histogramCallback(histogramType, histogramData);
}
}
}
Thread.sleep(_statsCollectionInterval);
} catch (final InterruptedException e) {
Thread.currentThread().interrupt();
break;
} catch (final Exception e) {
throw new RuntimeException("Error while calculating statistics", e);
}
}
};
}
}