org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/SimpleLruCacheBenchmark.java

/*
 * Copyright (C) 2019, Matthias Sohn <matthias.sohn@sap.com> and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
package org.eclipse.jgit.benchmarks;

import java.security.SecureRandom;
import java.util.concurrent.TimeUnit;

import org.eclipse.jgit.util.SimpleLruCache;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Group;
import org.openjdk.jmh.annotations.GroupThreads;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.TearDown;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

@State(Scope.Benchmark)
public class SimpleLruCacheBenchmark {

	SecureRandom rnd = new SecureRandom();

	private volatile SimpleLruCache<String, String> cache = new SimpleLruCache<>(
			100, 0.2f);

	private volatile int i;

	@Setup
	public void setupBenchmark() {
		i = rnd.nextInt(250);
	}

	@TearDown
	public void teardown() {
		cache = null;
	}

	@Benchmark
	@Group("readwrite")
	@GroupThreads(1)
	@BenchmarkMode({ Mode.AverageTime })
	@OutputTimeUnit(TimeUnit.NANOSECONDS)
	public SimpleLruCache<String, String> testCacheWrite() {
		cache.put("k" + i, "v" + i);
		return cache;
	}

	@Benchmark
	@Group("readwrite")
	@GroupThreads(1)
	@BenchmarkMode({ Mode.AverageTime })
	@OutputTimeUnit(TimeUnit.NANOSECONDS)
	public SimpleLruCache<String, String> testCacheRead() {
		cache.get("k" + i);
		return cache;
	}

	public static void main(String[] args) throws RunnerException {
		Options opt = new OptionsBuilder()
				.include(SimpleLruCacheBenchmark.class.getSimpleName())
				// .addProfiler(StackProfiler.class)
				// .addProfiler(GCProfiler.class)
				.forks(1).jvmArgs("-ea").build();
		new Runner(opt).run();
	}
}