/*
* Copyright (c) 2013-2017 Cinchapi Inc.
*
* Licensed 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 com.cinchapi.concourse.test;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import org.junit.Assert;
import com.google.common.base.Preconditions;
import com.google.common.base.Stopwatch;
import com.google.common.collect.Maps;
/**
* The base class for unit tests that benchmark performance.
* <p>
* <strong>NOTE:</strong> This framework should not be used for measuring
* precise performance metrics. Its really designed to provide relative
* benchmarking to give a general sense about how a unit performs.
* </p>
* <p>
* You can assert that one benchmark is faster than another one by using the
* {@link #assertFasterThan(String, String)} method.
* </p>
*
* @author Jeff Nelson
*/
public class ConcourseBenchmarkTest extends ConcourseBaseTest {
/**
* A collection from keys to stopwatches that encapsulates various
* benchmarks that are taken in the test methods.
*/
private final Map<String, Stopwatch> benchmarks = Maps.newHashMap();
@Override
public void afterEachTest() {
TimeUnit unit = desiredTimeUnit();
for (Map.Entry<String, Stopwatch> entry : benchmarks.entrySet()) {
System.out.println("Benchmark " + entry.getKey() + " took "
+ entry.getValue().elapsed(unit) + " "
+ unit.name().toLowerCase());
}
super.afterEachTest();
}
/**
* Assert that the {@code faster} benchmark ran in less time than the
* {@code slower} benchmark.
*
* @param faster the name of the benchmark that is expected to be faster
* @param slower the name of the benchmark that is expected to be slower
*/
protected void assertFasterThan(String faster, String slower) {
Stopwatch f = benchmarks.get(faster);
Stopwatch s = benchmarks.get(slower);
TimeUnit unit = desiredTimeUnit();
Preconditions.checkArgument(f != null, "% is not a valid benchmark",
faster);
Preconditions.checkArgument(s != null, "% is not a valid benchmark",
slower);
Assert.assertTrue(f.elapsed(unit) < s.elapsed(unit));
}
/**
* Return the {@link TimeUnit} that should be used when displaying the
* results of the benchmark and comparing the benchmark to others.
* <p>
* The default unit is {@link TimeUnit#MILLISECONDS milliseconds}.
* </p>
*
* @return the desired {@link TimeUnit}
*/
protected TimeUnit desiredTimeUnit() {
return TimeUnit.MILLISECONDS;
}
/**
* Start running the benchmark called {@code name}.
*
* <pre>
* @Test
* public void testFoo() {
* startBenchmark("foo");
* // ... benchmark code
* stopBenchmark("foo");
* }
* </pre>
*
* @param name the name of the benchmark
*/
protected void startBenchmark(String name) {
Stopwatch watch = Stopwatch.createUnstarted();
benchmarks.put(name, watch);
watch.start();
}
/**
* Stop running the benchmark called {@code name}.
*
* <pre>
* @Test
* public void testFoo() {
* startBenchmark("foo");
* // ... benchmark code
* stopBenchmark("foo");
* }
* </pre>
*
* @param name the name of the benchmark
*/
protected void stopBenchmark(String name) {
Stopwatch watch = benchmarks.get(name);
watch.stop();
System.gc();
}
}