init

test/org/apache/tomcat/util/buf/TestCharsetCachePerformance.java

@@ -0,0 +1,141 @@
+/*
+ *  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.Test;
+
+public class TestCharsetCachePerformance {
+
+    @Test
+    public void testNoCsCache() throws Exception {
+        doTest(new NoCsCache());
+    }
+
+
+    @Test
+    public void testFullCsCache() throws Exception {
+        doTest(new FullCsCache());
+    }
+
+
+    @Test
+    public void testLazyCsCache() throws Exception {
+        doTest(new LazyCsCache());
+    }
+
+
+    private void 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");
+    }
+
+
+    private static 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;
+
+        public 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]);
+            }
+        }
+    }
+}