/*
* Copyright (C) 2011 The Guava Authors
*
* 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.google.common.hash;
import static com.google.common.hash.Hashing.murmur3_32;
import com.google.common.hash.HashTestUtils.HashFn;
import junit.framework.TestCase;
/**
* Tests for {@link Murmur3_32HashFunction}.
*/
public class Murmur3Hash32Test extends TestCase {
public void testKnownIntegerInputs() {
assertHash(593689054, murmur3_32().hashInt(0));
assertHash(-189366624, murmur3_32().hashInt(-42));
assertHash(-1134849565, murmur3_32().hashInt(42));
assertHash(-1718298732, murmur3_32().hashInt(Integer.MIN_VALUE));
assertHash(-1653689534, murmur3_32().hashInt(Integer.MAX_VALUE));
}
public void testKnownLongInputs() {
assertHash(1669671676, murmur3_32().hashLong(0L));
assertHash(-846261623, murmur3_32().hashLong(-42L));
assertHash(1871679806, murmur3_32().hashLong(42L));
assertHash(1366273829, murmur3_32().hashLong(Long.MIN_VALUE));
assertHash(-2106506049, murmur3_32().hashLong(Long.MAX_VALUE));
}
public void testKnownStringInputs() {
assertHash(0, murmur3_32().hashUnencodedChars(""));
assertHash(679745764, murmur3_32().hashUnencodedChars("k"));
assertHash(1510782915, murmur3_32().hashUnencodedChars("hell"));
assertHash(-675079799, murmur3_32().hashUnencodedChars("hello"));
assertHash(1935035788, murmur3_32().hashUnencodedChars("http://www.google.com/"));
assertHash(-528633700,
murmur3_32().hashUnencodedChars("The quick brown fox jumps over the lazy dog"));
}
private static void assertHash(int expected, HashCode actual) {
assertEquals(HashCode.fromInt(expected), actual);
}
public void testParanoid() {
HashFn hf = new HashFn() {
@Override public byte[] hash(byte[] input, int seed) {
Hasher hasher = murmur3_32(seed).newHasher();
Funnels.byteArrayFunnel().funnel(input, hasher);
return hasher.hash().asBytes();
}
};
// Murmur3A, MurmurHash3 for x86, 32-bit (MurmurHash3_x86_32)
// http://code.google.com/p/smhasher/source/browse/trunk/main.cpp
HashTestUtils.verifyHashFunction(hf, 32, 0xB0F57EE3);
}
public void testInvariants() {
HashTestUtils.assertInvariants(murmur3_32());
}
}