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Commons Math example source code file (OpenIntToDoubleHashMapTest.java)

This example Commons Math source code file (OpenIntToDoubleHashMapTest.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 Math tags/keywords

double, double, hashmap, hashmap, map, map, nosuchelementexception, openinttodoublehashmap, openinttodoublehashmap, openinttodoublehashmaptest, override, random, set, testcase, util

The Commons Math OpenIntToDoubleHashMapTest.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.math.util;

import java.util.ConcurrentModificationException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Random;
import java.util.Set;

import junit.framework.TestCase;

/**
 * Test cases for the {@link OpenIntToDoubleHashMap}.
 */
public class OpenIntToDoubleHashMapTest extends TestCase {

    private Map<Integer, Double> javaMap = new HashMap();

    @Override
    protected void setUp() throws Exception {
        javaMap.put(50, 100.0);
        javaMap.put(75, 75.0);
        javaMap.put(25, 500.0);
        javaMap.put(Integer.MAX_VALUE, Double.MAX_VALUE);
        javaMap.put(0, -1.0);
        javaMap.put(1, 0.0);
        javaMap.put(33, -0.1);
        javaMap.put(23234234, -242343.0);
        javaMap.put(23321, Double.MIN_VALUE);
        javaMap.put(-4444, 332.0);
        javaMap.put(-1, -2323.0);
        javaMap.put(Integer.MIN_VALUE, 44.0);

        /* Add a few more to cause the table to rehash */
        javaMap.putAll(generate());

    }

    private Map<Integer, Double> generate() {
        Map<Integer, Double> map = new HashMap();
        Random r = new Random();
        for (int i = 0; i < 2000; ++i)
            map.put(r.nextInt(), r.nextDouble());
        return map;
    }

    private OpenIntToDoubleHashMap createFromJavaMap() {
        OpenIntToDoubleHashMap map = new OpenIntToDoubleHashMap();
        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet()) {
            map.put(mapEntry.getKey(), mapEntry.getValue());
        }
        return map;
    }

    public void testPutAndGetWith0ExpectedSize() {
        OpenIntToDoubleHashMap map = new OpenIntToDoubleHashMap(0);
        assertPutAndGet(map);
    }

    public void testPutAndGetWithExpectedSize() {
        OpenIntToDoubleHashMap map = new OpenIntToDoubleHashMap(500);
        assertPutAndGet(map);
    }

    public void testPutAndGet() {
        OpenIntToDoubleHashMap map = new OpenIntToDoubleHashMap();
        assertPutAndGet(map);
    }

    private void assertPutAndGet(OpenIntToDoubleHashMap map) {
        assertPutAndGet(map, 0, new HashSet<Integer>());
    }

    private void assertPutAndGet(OpenIntToDoubleHashMap map, int mapSize,
            Set<Integer> keysInMap) {
        assertEquals(mapSize, map.size());
        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet()) {
            map.put(mapEntry.getKey(), mapEntry.getValue());
            if (!keysInMap.contains(mapEntry.getKey()))
                ++mapSize;
            assertEquals(mapSize, map.size());
            assertEquals(mapEntry.getValue(), map.get(mapEntry.getKey()));
        }
    }

    public void testPutAbsentOnExisting() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        int size = javaMap.size();
        for (Map.Entry<Integer, Double> mapEntry : generateAbsent().entrySet()) {
            map.put(mapEntry.getKey(), mapEntry.getValue());
            assertEquals(++size, map.size());
            assertEquals(mapEntry.getValue(), map.get(mapEntry.getKey()));
        }
    }

    public void testPutOnExisting() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet()) {
            map.put(mapEntry.getKey(), mapEntry.getValue());
            assertEquals(javaMap.size(), map.size());
            assertEquals(mapEntry.getValue(), map.get(mapEntry.getKey()));
        }
    }

    public void testGetAbsent() {
        Map<Integer, Double> generated = generateAbsent();
        OpenIntToDoubleHashMap map = createFromJavaMap();

        for (Map.Entry<Integer, Double> mapEntry : generated.entrySet())
            assertTrue(Double.isNaN(map.get(mapEntry.getKey())));
    }

    public void testGetFromEmpty() {
        OpenIntToDoubleHashMap map = new OpenIntToDoubleHashMap();
        assertTrue(Double.isNaN(map.get(5)));
        assertTrue(Double.isNaN(map.get(0)));
        assertTrue(Double.isNaN(map.get(50)));
    }

    public void testRemove() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        int mapSize = javaMap.size();
        assertEquals(mapSize, map.size());
        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet()) {
            map.remove(mapEntry.getKey());
            assertEquals(--mapSize, map.size());
            assertTrue(Double.isNaN(map.get(mapEntry.getKey())));
        }

        /* Ensure that put and get still work correctly after removals */
        assertPutAndGet(map);
    }

    /* This time only remove some entries */
    public void testRemove2() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        int mapSize = javaMap.size();
        int count = 0;
        Set<Integer> keysInMap = new HashSet(javaMap.keySet());
        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet()) {
            keysInMap.remove(mapEntry.getKey());
            map.remove(mapEntry.getKey());
            assertEquals(--mapSize, map.size());
            assertTrue(Double.isNaN(map.get(mapEntry.getKey())));
            if (count++ > 5)
                break;
        }

        /* Ensure that put and get still work correctly after removals */
        assertPutAndGet(map, mapSize, keysInMap);
    }

    public void testRemoveFromEmpty() {
        OpenIntToDoubleHashMap map = new OpenIntToDoubleHashMap();
        assertTrue(Double.isNaN(map.remove(50)));
    }

    public void testRemoveAbsent() {
        Map<Integer, Double> generated = generateAbsent();

        OpenIntToDoubleHashMap map = createFromJavaMap();
        int mapSize = map.size();

        for (Map.Entry<Integer, Double> mapEntry : generated.entrySet()) {
            map.remove(mapEntry.getKey());
            assertEquals(mapSize, map.size());
            assertTrue(Double.isNaN(map.get(mapEntry.getKey())));
        }
    }

    /**
     * Returns a map with at least 100 elements where each element is absent from javaMap.
     */
    private Map<Integer, Double> generateAbsent() {
        Map<Integer, Double> generated = new HashMap();
        do {
            generated.putAll(generate());
            for (Integer key : javaMap.keySet())
                generated.remove(key);
        } while (generated.size() < 100);
        return generated;
    }

    public void testCopy() {
        OpenIntToDoubleHashMap copy =
            new OpenIntToDoubleHashMap(createFromJavaMap());
        assertEquals(javaMap.size(), copy.size());

        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet())
            assertEquals(mapEntry.getValue(), copy.get(mapEntry.getKey()));
    }

    public void testContainsKey() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet()) {
            assertTrue(map.containsKey(mapEntry.getKey()));
        }
        for (Map.Entry<Integer, Double> mapEntry : generateAbsent().entrySet()) {
            assertFalse(map.containsKey(mapEntry.getKey()));
        }
        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet()) {
            int key = mapEntry.getKey();
            assertTrue(map.containsKey(key));
            map.remove(key);
            assertFalse(map.containsKey(key));
        }
    }

    public void testIterator() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        OpenIntToDoubleHashMap.Iterator iterator = map.iterator();
        for (int i = 0; i < map.size(); ++i) {
            assertTrue(iterator.hasNext());
            iterator.advance();
            int key = iterator.key();
            assertTrue(map.containsKey(key));
            assertEquals(javaMap.get(key), map.get(key), 0);
            assertEquals(javaMap.get(key), iterator.value(), 0);
            assertTrue(javaMap.containsKey(key));
        }
        assertFalse(iterator.hasNext());
        try {
            iterator.advance();
            fail("an exception should have been thrown");
        } catch (NoSuchElementException nsee) {
            // expected
        }
    }

    public void testConcurrentModification() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        OpenIntToDoubleHashMap.Iterator iterator = map.iterator();
        map.put(3, 3);
        try {
            iterator.advance();
            fail("an exception should have been thrown");
        } catch (ConcurrentModificationException cme) {
            // expected
        }
    }

    /**
     * Regression test for a bug in findInsertionIndex where the hashing in the second probing
     * loop was inconsistent with the first causing duplicate keys after the right sequence
     * of puts and removes.
     */
    public void testPutKeysWithCollisions() {
        OpenIntToDoubleHashMap map = new OpenIntToDoubleHashMap();
        int key1 = -1996012590;
        double value1 = 1.0;
        map.put(key1, value1);
        int key2 = 835099822;
        map.put(key2, value1);
        int key3 = 1008859686;
        map.put(key3, value1);
        assertEquals(value1, map.get(key3));
        assertEquals(3, map.size());

        map.remove(key2);
        double value2 = 2.0;
        map.put(key3, value2);
        assertEquals(value2, map.get(key3));
        assertEquals(2, map.size());
    }

    /**
     * Similar to testPutKeysWithCollisions() but exercises the codepaths in a slightly
     * different manner.
     */
    public void testPutKeysWithCollision2() {
        OpenIntToDoubleHashMap map = new OpenIntToDoubleHashMap();
        int key1 = 837989881;
        double value1 = 1.0;
        map.put(key1, value1);
        int key2 = 476463321;
        map.put(key2, value1);
        assertEquals(2, map.size());
        assertEquals(value1, map.get(key2));

        map.remove(key1);
        double value2 = 2.0;
        map.put(key2, value2);
        assertEquals(1, map.size());
        assertEquals(value2, map.get(key2));
    }

}

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