src/test/java/org/apache/commons/codec/digest/MurmurHash2Test.java

/*
 * 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.codec.digest;

import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import org.junit.Test;

public class MurmurHash2Test {

	/** Random input data with various length. */
	static final byte[][] input = {
			{ (byte) 0xed, (byte) 0x53, (byte) 0xc4, (byte) 0xa5, (byte) 0x3b, (byte) 0x1b, (byte) 0xbd, (byte) 0xc2,
					(byte) 0x52, (byte) 0x7d, (byte) 0xc3, (byte) 0xef, (byte) 0x53, (byte) 0x5f, (byte) 0xae,
					(byte) 0x3b },
			{ (byte) 0x21, (byte) 0x65, (byte) 0x59, (byte) 0x4e, (byte) 0xd8, (byte) 0x12, (byte) 0xf9, (byte) 0x05,
					(byte) 0x80, (byte) 0xe9, (byte) 0x1e, (byte) 0xed, (byte) 0xe4, (byte) 0x56, (byte) 0xbb },
			{ (byte) 0x2b, (byte) 0x02, (byte) 0xb1, (byte) 0xd0, (byte) 0x3d, (byte) 0xce, (byte) 0x31, (byte) 0x3d,
					(byte) 0x97, (byte) 0xc4, (byte) 0x91, (byte) 0x0d, (byte) 0xf7, (byte) 0x17 },
			{ (byte) 0x8e, (byte) 0xa7, (byte) 0x9a, (byte) 0x02, (byte) 0xe8, (byte) 0xb9, (byte) 0x6a, (byte) 0xda,
					(byte) 0x92, (byte) 0xad, (byte) 0xe9, (byte) 0x2d, (byte) 0x21 },
			{ (byte) 0xa9, (byte) 0x6d, (byte) 0xea, (byte) 0x77, (byte) 0x06, (byte) 0xce, (byte) 0x1b, (byte) 0x85,
					(byte) 0x48, (byte) 0x27, (byte) 0x4c, (byte) 0xfe },
			{ (byte) 0xec, (byte) 0x93, (byte) 0xa0, (byte) 0x12, (byte) 0x60, (byte) 0xee, (byte) 0xc8, (byte) 0x0a,
					(byte) 0xc5, (byte) 0x90, (byte) 0x62 },
			{ (byte) 0x55, (byte) 0x6d, (byte) 0x93, (byte) 0x66, (byte) 0x14, (byte) 0x6d, (byte) 0xdf, (byte) 0x00,
					(byte) 0x58, (byte) 0x99 },
			{ (byte) 0x3c, (byte) 0x72, (byte) 0x20, (byte) 0x1f, (byte) 0xd2, (byte) 0x59, (byte) 0x19, (byte) 0xdb,
					(byte) 0xa1 },
			{ (byte) 0x23, (byte) 0xa8, (byte) 0xb1, (byte) 0x87, (byte) 0x55, (byte) 0xf7, (byte) 0x8a, (byte) 0x4b,

			}, { (byte) 0xe2, (byte) 0x42, (byte) 0x1c, (byte) 0x2d, (byte) 0xc1, (byte) 0xe4, (byte) 0x3e },
			{ (byte) 0x66, (byte) 0xa6, (byte) 0xb5, (byte) 0x5a, (byte) 0x74, (byte) 0xd9 },
			{ (byte) 0xe8, (byte) 0x76, (byte) 0xa8, (byte) 0x90, (byte) 0x76 },
			{ (byte) 0xeb, (byte) 0x25, (byte) 0x3f, (byte) 0x87 }, { (byte) 0x37, (byte) 0xa0, (byte) 0xa9 },
			{ (byte) 0x5b, (byte) 0x5d }, { (byte) 0x7e }, {} };

	/*
	 * Expected results - from the original C implementation.
	 */

	/** Murmur 32bit hash results, default library seed. */
	static final int[] results32_standard = { 0x96814fb3, 0x485dcaba, 0x331dc4ae, 0xc6a7bf2f, 0xcdf35de0, 0xd9dec7cc,
			0x63a7318a, 0xd0d3c2de, 0x90923aef, 0xaf35c1e2, 0x735377b2, 0x366c98f3, 0x9c48ee29, 0x0b615790, 0xb4308ac1,
			0xec98125a, 0x106e08d9 };

	/** Murmur 32bit hash results, special test seed. */
	static final int[] results32_seed = { 0xd92e493e, 0x8b50903b, 0xc3372a7b, 0x48f07e9e, 0x8a5e4a6e, 0x57916df4,
			0xa346171f, 0x1e319c86, 0x9e1a03cd, 0x9f973e6c, 0x2d8c77f5, 0xabed8751, 0x296708b6, 0x24f8078b, 0x111b1553,
			0xa7da1996, 0xfe776c70 };

	/** Murmur 64bit hash results, default library seed. */
	static final long[] results64_standard = { 0x4987cb15118a83d9l, 0x28e2a79e3f0394d9l, 0x8f4600d786fc5c05l,
			0xa09b27fea4b54af3l, 0x25f34447525bfd1el, 0x32fad4c21379c7bfl, 0x4b30b99a9d931921l, 0x4e5dab004f936cdbl,
			0x06825c27bc96cf40l, 0xff4bf2f8a4823905l, 0x7f7e950c064e6367l, 0x821ade90caaa5889l, 0x6d28c915d791686al,
			0x9c32649372163ba2l, 0xd66ae956c14d5212l, 0x38ed30ee5161200fl, 0x9bfae0a4e613fc3cl, };

	/** Murmur 64bit hash results, special test seed. */
	static final long[] results64_seed = { 0x0822b1481a92e97bl, 0xf8a9223fef0822ddl, 0x4b49e56affae3a89l,
			0xc970296e32e1d1c1l, 0xe2f9f88789f1b08fl, 0x2b0459d9b4c10c61l, 0x377e97ea9197ee89l, 0xd2ccad460751e0e7l,
			0xff162ca8d6da8c47l, 0xf12e051405769857l, 0xdabba41293d5b035l, 0xacf326b0bb690d0el, 0x0617f431bc1a8e04l,
			0x15b81f28d576e1b2l, 0x28c1fe59e4f8e5bal, 0x694dd315c9354ca9l, 0xa97052a8f088ae6cl };

	/** Dummy test text. */
	static final String text = "Lorem ipsum dolor sit amet, consectetur adipisicing elit";

	@Test
	public void testHash32ByteArrayIntInt() {
		for (int i = 0; i < input.length; i++) {
			final int hash = MurmurHash2.hash32(input[i], input[i].length, 0x71b4954d);
			if (hash != results32_seed[i]) {
                fail(String.format("Unexpected hash32 result for example %d: 0x%08x instead of 0x%08x", i, hash,
						results32_seed[i]));
            }
		}
	}

	@Test
	public void testHash32ByteArrayInt() {
		for (int i = 0; i < input.length; i++) {
			final int hash = MurmurHash2.hash32(input[i], input[i].length);
			if (hash != results32_standard[i]) {
                fail(String.format("Unexpected hash32 result for example %d: 0x%08x instead of 0x%08x", i, hash,
						results32_standard[i]));
            }
		}
	}

	@Test
	public void testHash32String() {
		final int hash = MurmurHash2.hash32(text);
		assertTrue(hash == 0xb3bf597e);
	}

	@Test
	public void testHash32StringIntInt() {
		final int hash = MurmurHash2.hash32(text, 2, text.length() - 4);
		assertTrue(hash == 0x4d666d90);
	}

	@Test
	public void testHash64ByteArrayIntInt() {
		for (int i = 0; i < input.length; i++) {
			final long hash = MurmurHash2.hash64(input[i], input[i].length, 0x344d1f5c);
			assertTrue(String.format("Unexpected hash64 result for example %d: 0x%016x instead of 0x%016x", i, hash,
					results64_seed[i]), hash == results64_seed[i]);
		}
	}

	@Test
	public void testHash64ByteArrayInt() {
		for (int i = 0; i < input.length; i++) {
			final long hash = MurmurHash2.hash64(input[i], input[i].length);
			assertTrue(String.format("Unexpected hash64 result for example %d: 0x%016x instead of 0x%016x", i, hash,
					results64_standard[i]), hash == results64_standard[i]);
		}
	}

	@Test
	public void testHash64String() {
		final long hash = MurmurHash2.hash64(text);
		assertTrue(hash == 0x0920e0c1b7eeb261l);
	}

	@Test
	public void testHash64StringIntInt() {
		final long hash = MurmurHash2.hash64(text, 2, text.length() - 4);
		assertTrue(hash == 0xa8b33145194985a2l);
	}

}