/**
* 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.mahout.cf.taste.impl.common;
import org.apache.mahout.cf.taste.impl.TasteTestCase;
import org.apache.mahout.common.RandomUtils;
import org.junit.Test;
import java.util.Collection;
import java.util.HashSet;
import java.util.Random;
/** <p>Tests {@link FastIDSet}.</p> */
public final class FastIDSetTest extends TasteTestCase {
@Test
public void testContainsAndAdd() {
FastIDSet set = new FastIDSet();
assertFalse(set.contains(1));
set.add(1);
assertTrue(set.contains(1));
}
@Test
public void testRemove() {
FastIDSet set = new FastIDSet();
set.add(1);
set.remove(1);
assertEquals(0, set.size());
assertTrue(set.isEmpty());
assertFalse(set.contains(1));
}
@Test
public void testClear() {
FastIDSet set = new FastIDSet();
set.add(1);
set.clear();
assertEquals(0, set.size());
assertTrue(set.isEmpty());
assertFalse(set.contains(1));
}
@Test
public void testSizeEmpty() {
FastIDSet set = new FastIDSet();
assertEquals(0, set.size());
assertTrue(set.isEmpty());
set.add(1);
assertEquals(1, set.size());
assertFalse(set.isEmpty());
set.remove(1);
assertEquals(0, set.size());
assertTrue(set.isEmpty());
}
@Test
public void testContains() {
FastIDSet set = buildTestFastSet();
assertTrue(set.contains(1));
assertTrue(set.contains(2));
assertTrue(set.contains(3));
assertFalse(set.contains(4));
}
@Test
public void testReservedValues() {
FastIDSet set = new FastIDSet();
try {
set.add(Long.MIN_VALUE);
fail("Should have thrown IllegalArgumentException");
} catch (IllegalArgumentException iae) {
// good
}
assertFalse(set.contains(Long.MIN_VALUE));
try {
set.add(Long.MAX_VALUE);
fail("Should have thrown IllegalArgumentException");
} catch (IllegalArgumentException iae) {
// good
}
assertFalse(set.contains(Long.MAX_VALUE));
}
@Test
public void testRehash() {
FastIDSet set = buildTestFastSet();
set.remove(1);
set.rehash();
assertFalse(set.contains(1));
}
@Test
public void testGrow() {
FastIDSet set = new FastIDSet(1);
set.add(1);
set.add(2);
assertTrue(set.contains(1));
assertTrue(set.contains(2));
}
@Test
public void testIterator() {
FastIDSet set = buildTestFastSet();
Collection<Long> expected = new HashSet<Long>(3);
expected.add(1L);
expected.add(2L);
expected.add(3L);
LongPrimitiveIterator it = set.iterator();
while (it.hasNext()) {
expected.remove(it.nextLong());
}
assertTrue(expected.isEmpty());
}
@Test
public void testVersusHashSet() {
FastIDSet actual = new FastIDSet(1);
Collection<Integer> expected = new HashSet<Integer>(1000000);
Random r = RandomUtils.getRandom();
for (int i = 0; i < 1000000; i++) {
double d = r.nextDouble();
Integer key = r.nextInt(100);
if (d < 0.4) {
assertEquals(expected.contains(key), actual.contains(key));
} else {
if (d < 0.7) {
assertEquals(expected.add(key), actual.add(key));
} else {
assertEquals(expected.remove(key), actual.remove(key));
}
assertEquals(expected.size(), actual.size());
assertEquals(expected.isEmpty(), actual.isEmpty());
}
}
}
private static FastIDSet buildTestFastSet() {
FastIDSet set = new FastIDSet();
set.add(1);
set.add(2);
set.add(3);
return set;
}
}