/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.util;
import com.hazelcast.test.HazelcastSerialClassRunner;
import com.hazelcast.test.annotation.QuickTest;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.runner.RunWith;
import java.math.BigInteger;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
/**
* Unit tests for {@link QuickMath} class.
*/
@RunWith(HazelcastSerialClassRunner.class)
@Category(QuickTest.class)
public class QuickMathTest {
@Test
public void testIsPowerOfTwo() {
assertTrue(QuickMath.isPowerOfTwo(1));
assertTrue(QuickMath.isPowerOfTwo(2));
assertFalse(QuickMath.isPowerOfTwo(3));
assertTrue(QuickMath.isPowerOfTwo(1024));
assertFalse(QuickMath.isPowerOfTwo(1023));
assertFalse(QuickMath.isPowerOfTwo(Integer.MAX_VALUE));
}
@Test
public void testNextPowerOfTwo() {
assertEquals(1, QuickMath.nextPowerOfTwo(-9999999));
assertEquals(1, QuickMath.nextPowerOfTwo(-1));
assertEquals(1, QuickMath.nextPowerOfTwo(0));
assertEquals(1, QuickMath.nextPowerOfTwo(1));
assertEquals(2, QuickMath.nextPowerOfTwo(2));
assertEquals(1024, QuickMath.nextPowerOfTwo(999));
assertEquals(1 << 23, QuickMath.nextPowerOfTwo((1 << 23) - 1));
assertEquals(1 << 23, QuickMath.nextPowerOfTwo(1 << 23));
assertEquals(2048L, QuickMath.nextPowerOfTwo(2000L));
assertEquals(1L << 33, QuickMath.nextPowerOfTwo((1L << 33) - 3));
assertEquals(1L << 43, QuickMath.nextPowerOfTwo((1L << 43)));
}
@Test
public void testNextLongPowerOfTwo() {
assertEquals(1L, QuickMath.nextPowerOfTwo(-9999999L));
assertEquals(1L, QuickMath.nextPowerOfTwo(-1L));
assertEquals(1L, QuickMath.nextPowerOfTwo(0L));
assertEquals(1L, QuickMath.nextPowerOfTwo(1L));
assertEquals(2L, QuickMath.nextPowerOfTwo(2L));
assertEquals(4L, QuickMath.nextPowerOfTwo(3L));
assertEquals(1L << 62, QuickMath.nextPowerOfTwo((1L << 61) + 1));
}
@Test
public void testModPowerOfTwo() {
int[] aParams = new int[]{
0, 1, Integer.MAX_VALUE / 2, Integer.MAX_VALUE
};
int[] bParams = new int[]{
1, 2, 1024, powerOfTwo(10), powerOfTwo(20)
};
for (int a : aParams) {
for (int b : bParams) {
assertEquals(a % b, QuickMath.modPowerOfTwo(a, b));
}
}
}
private int powerOfTwo(int x) {
return BigInteger.valueOf(2).pow(x).intValue();
}
}