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Java example source code file (OpenIntToDoubleHashMapTest.java)

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

Learn more about this Java project at its project page.

Java - Java tags/keywords

before, concurrentmodificationexception, double, hashset, integer, map, nosuchelementexception, openinttodoublehashmap, openinttodoublehashmaptest, random, set, suppresswarnings, test, util

The OpenIntToDoubleHashMapTest.java Java example 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.math3.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 org.junit.Assert;
import org.junit.Before;
import org.junit.Test;


/**
 * Test cases for the {@link OpenIntToDoubleHashMap}.
 */
@SuppressWarnings("boxing")
public class OpenIntToDoubleHashMapTest {

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

    @Before
    public 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;
    }

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

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

    @Test
    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) {
        Assert.assertEquals(mapSize, map.size());
        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet()) {
            map.put(mapEntry.getKey(), mapEntry.getValue());
            if (!keysInMap.contains(mapEntry.getKey()))
                ++mapSize;
            Assert.assertEquals(mapSize, map.size());
            Assert.assertTrue(Precision.equals(mapEntry.getValue(), map.get(mapEntry.getKey()), 1));
        }
    }

    @Test
    public void testPutAbsentOnExisting() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        int size = javaMap.size();
        for (Map.Entry<Integer, Double> mapEntry : generateAbsent().entrySet()) {
            map.put(mapEntry.getKey(), mapEntry.getValue());
            Assert.assertEquals(++size, map.size());
            Assert.assertTrue(Precision.equals(mapEntry.getValue(), map.get(mapEntry.getKey()), 1));
        }
    }

    @Test
    public void testPutOnExisting() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet()) {
            map.put(mapEntry.getKey(), mapEntry.getValue());
            Assert.assertEquals(javaMap.size(), map.size());
            Assert.assertTrue(Precision.equals(mapEntry.getValue(), map.get(mapEntry.getKey()), 1));
        }
    }

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

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

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

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

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

    @Test
    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());
            Assert.assertEquals(mapSize, map.size());
            Assert.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;
    }

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

        for (Map.Entry<Integer, Double> mapEntry : javaMap.entrySet())
            Assert.assertTrue(Precision.equals(mapEntry.getValue(), copy.get(mapEntry.getKey()), 1));
    }

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

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

    @Test
    public void testConcurrentModification() {
        OpenIntToDoubleHashMap map = createFromJavaMap();
        OpenIntToDoubleHashMap.Iterator iterator = map.iterator();
        map.put(3, 3);
        try {
            iterator.advance();
            Assert.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.
     */
    @Test
    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);
        Assert.assertTrue(Precision.equals(value1, map.get(key3), 1));
        Assert.assertEquals(3, map.size());

        map.remove(key2);
        double value2 = 2.0;
        map.put(key3, value2);
        Assert.assertTrue(Precision.equals(value2, map.get(key3), 1));
        Assert.assertEquals(2, map.size());
    }

    /**
     * Similar to testPutKeysWithCollisions() but exercises the codepaths in a slightly
     * different manner.
     */
    @Test
    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);
        Assert.assertEquals(2, map.size());
        Assert.assertTrue(Precision.equals(value1, map.get(key2), 1));

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

}

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