Commons Collections example source code file (MapPerformance.java)

This example Commons Collections source code file (MapPerformance.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Collections tags/keywords

beta, dummy, dummymap, e, flat3, flat3, hashmap, hashmap, map, map, object, object, runs, set, util

The Commons Collections MapPerformance.java source code

/*
 *  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.commons.collections;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

import org.apache.commons.collections.map.Flat3Map;

/** 
 * <code>TestMapPerformance is designed to perform basic Map performance tests.
 *
 * @author Stephen Colebourne
 */
public class MapPerformance {

    /** The total number of runs for each test */    
    private static final int RUNS = 20000000;
    
    /**
     * Main method
     */
    public static void main(String[] args) {
        testAll();
    }
    
    private static void testAll() {
        Map dummyMap = new DummyMap();
        Map hashMap = new HashMap();
//        hashMap.put("Alpha", "A");
//        hashMap.put("Beta", "B");
//        hashMap.put("Gamma", "C");
//        hashMap.put("Delta", "D");
        Map flatMap = new Flat3Map(hashMap);
        System.out.println(flatMap);
        Map unmodHashMap = Collections.unmodifiableMap(new HashMap(hashMap));
        Map fastHashMap = new FastHashMap(hashMap);
        Map treeMap = new TreeMap(hashMap);
        Map seqMap = new SequencedHashMap(hashMap);
//        Map linkedMap = new LinkedHashMap(hashMap);
//        Map syncMap = Collections.unmodifiableMap(new HashMap(hashMap));
//        Map bucketMap = new StaticBucketMap();
//        bucketMap.putAll(hashMap);
//        Map doubleMap = new DoubleOrderedMap(hashMap);
        
        // dummy is required as the VM seems to hotspot the first call to the
        // test method with the given type
        test(dummyMap,      "         Dummy ");
        test(dummyMap,      "         Dummy ");
        test(dummyMap,      "         Dummy ");
        test(flatMap,       "         Flat3 ");
        test(hashMap,       "       HashMap ");
        
        test(flatMap,       "         Flat3 ");
        test(flatMap,       "         Flat3 ");
        test(flatMap,       "         Flat3 ");
        
        test(hashMap,       "       HashMap ");
        test(hashMap,       "       HashMap ");
        test(hashMap,       "       HashMap ");
        
//        test(treeMap,       "       TreeMap ");
//        test(treeMap,       "       TreeMap ");
//        test(treeMap,       "       TreeMap ");
        
//        test(unmodHashMap,  "Unmod(HashMap) ");
//        test(unmodHashMap,  "Unmod(HashMap) ");
//        test(unmodHashMap,  "Unmod(HashMap) ");
//        
//        test(syncMap,       " Sync(HashMap) ");
//        test(syncMap,       " Sync(HashMap) ");
//        test(syncMap,       " Sync(HashMap) ");
//        
//        test(fastHashMap,   "   FastHashMap ");
//        test(fastHashMap,   "   FastHashMap ");
//        test(fastHashMap,   "   FastHashMap ");
//        
//        test(seqMap,        "    SeqHashMap ");
//        test(seqMap,        "    SeqHashMap ");
//        test(seqMap,        "    SeqHashMap ");
//        
//        test(linkedMap,     " LinkedHashMap ");
//        test(linkedMap,     " LinkedHashMap ");
//        test(linkedMap,     " LinkedHashMap ");
//        
//        test(bucketMap,     "     BucketMap ");
//        test(bucketMap,     "     BucketMap ");
//        test(bucketMap,     "     BucketMap ");
//        
//        test(doubleMap,     "     DoubleMap ");
//        test(doubleMap,     "     DoubleMap ");
//        test(doubleMap,     "     DoubleMap ");
    }

    private static void test(Map map, String name) {
        long start = 0, end = 0;
        int total = 0;
        start = System.currentTimeMillis();
        for (int i = RUNS; i > 0; i--) {
//            if (map.get("Alpha") != null) total++;
//            if (map.get("Beta") != null) total++;
//            if (map.get("Gamma") != null) total++;
            map.put("Alpha", "A");
            map.put("Beta", "B");
            map.put("Beta", "C");
            map.put("Gamma", "D");
//            map.remove("Gamma");
//            map.remove("Beta");
//            map.remove("Alpha");
            map.put("Delta", "E");
            map.clear();
        }
        end = System.currentTimeMillis();
        System.out.println(name + (end - start));
    }

    // ----------------------------------------------------------------------

    private static class DummyMap implements Map {
        public void clear() {
        }
        public boolean containsKey(Object key) {
            return false;
        }
        public boolean containsValue(Object value) {
            return false;
        }
        public Set entrySet() {
            return null;
        }
        public Object get(Object key) {
            return null;
        }
        public boolean isEmpty() {
            return false;
        }
        public Set keySet() {
            return null;
        }
        public Object put(Object key, Object value) {
            return null;
        }
        public void putAll(Map t) {
        }
        public Object remove(Object key) {
            return null;
        }
        public int size() {
            return 0;
        }
        public Collection values() {
            return null;
        }
    }
    
}