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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.tomcat.util.buf;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import org.junit.Assert;
import org.junit.Test;
/*
* This is a relative performance test so it remains part of the standard test run.
*/
public class TestCharsetCachePerformance {
@Test
public void testCache() throws Exception {
long timeNone = doTest(new NoCsCache());
long timeFull = doTest(new FullCsCache());
long timeLazy = doTest(new LazyCsCache());
Assert.assertTrue("No cache was faster than full cache", timeFull < timeNone);
Assert.assertTrue("No cache was faster than lazy cache", timeLazy < timeNone);
// On average full cache is faster than lazy cache but they are close enough the test will fail sometimes
//Assert.assertTrue("Lazy cache was faster than full cache ", timeFull < timeLazy);
}
private long doTest(CsCache cache) throws Exception {
int threadCount = 10;
int iterations = 10000000;
String[] lookupNames = new String[] {
"ISO-8859-1", "ISO-8859-2", "ISO-8859-3", "ISO-8859-4", "ISO-8859-5" };
Thread[] threads = new Thread[threadCount];
for (int i = 0; i < threadCount; i++) {
threads[i] = new TestCsCacheThread(iterations, cache, lookupNames);
}
long startTime = System.nanoTime();
for (int i = 0; i < threadCount; i++) {
threads[i].start();
}
for (int i = 0; i < threadCount; i++) {
threads[i].join();
}
long endTime = System.nanoTime();
System.out.println(cache.getClass().getName() + ": " + (endTime - startTime) + "ns");
return endTime - startTime;
}
private interface CsCache {
Charset getCharset(String charsetName);
}
private static class NoCsCache implements CsCache {
@Override
public Charset getCharset(String charsetName) {
return Charset.forName(charsetName);
}
}
private static class FullCsCache implements CsCache {
private static final Map<String,Charset> cache = new HashMap<>();
static {
for (Charset charset: Charset.availableCharsets().values()) {
cache.put(charset.name().toLowerCase(Locale.ENGLISH), charset);
for (String alias : charset.aliases()) {
cache.put(alias.toLowerCase(Locale.ENGLISH), charset);
}
}
}
@Override
public Charset getCharset(String charsetName) {
return cache.get(charsetName.toLowerCase(Locale.ENGLISH));
}
}
private static class LazyCsCache implements CsCache {
private CharsetCache cache = new CharsetCache();
@Override
public Charset getCharset(String charsetName) {
return cache.getCharset(charsetName);
}
}
private static class TestCsCacheThread extends Thread {
private final int iterations;
private final CsCache cache;
private final String[] lookupNames;
private final int lookupNamesCount;
TestCsCacheThread(int iterations, CsCache cache, String[] lookupNames) {
this.iterations = iterations;
this.cache = cache;
this.lookupNames = lookupNames;
this.lookupNamesCount = lookupNames.length;
}
@Override
public void run() {
for (int i = 0; i < iterations; i++) {
cache.getCharset(lookupNames[i % lookupNamesCount]);
}
}
}
}
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