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1 /*
2  * Copyright (C) 2011 The Guava Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.google.common.hash;
18 
19 import static com.google.common.hash.Hashing.murmur3_128;
20 
21 import com.google.common.base.Charsets;
22 import com.google.common.hash.HashTestUtils.HashFn;
23 
24 import junit.framework.TestCase;
25 
26 import java.nio.ByteBuffer;
27 import java.nio.ByteOrder;
28 
29 /**
30  * Tests for {@link Murmur3_128HashFunction}.
31  */
32 public class Murmur3Hash128Test extends TestCase {
testKnownValues()33   public void testKnownValues() {
34     assertHash(0, 0x629942693e10f867L, 0x92db0b82baeb5347L, "hell");
35     assertHash(1, 0xa78ddff5adae8d10L, 0x128900ef20900135L, "hello");
36     assertHash(2, 0x8a486b23f422e826L, 0xf962a2c58947765fL, "hello ");
37     assertHash(3, 0x2ea59f466f6bed8cL, 0xc610990acc428a17L, "hello w");
38     assertHash(4, 0x79f6305a386c572cL, 0x46305aed3483b94eL, "hello wo");
39     assertHash(5, 0xc2219d213ec1f1b5L, 0xa1d8e2e0a52785bdL, "hello wor");
40     assertHash(0, 0xe34bbc7bbc071b6cL, 0x7a433ca9c49a9347L,
41         "The quick brown fox jumps over the lazy dog");
42     assertHash(0, 0x658ca970ff85269aL, 0x43fee3eaa68e5c3eL,
43         "The quick brown fox jumps over the lazy cog");
44 
45     // Known output from Python smhasher
46     HashCode foxHash =
47         murmur3_128(0).hashString("The quick brown fox jumps over the lazy dog", Charsets.UTF_8);
48     assertEquals("6c1b07bc7bbc4be347939ac4a93c437a", foxHash.toString());
49   }
50 
assertHash(int seed, long expected1, long expected2, String stringInput)51   private static void assertHash(int seed, long expected1, long expected2, String stringInput) {
52     HashCode expected = toHashCode(expected1, expected2);
53     byte[] input = HashTestUtils.ascii(stringInput);
54     assertEquals(expected, murmur3_128(seed).hashBytes(input));
55     assertEquals(expected, murmur3_128(seed).newHasher().putBytes(input).hash());
56   }
57 
58   /**
59    * Returns a {@link HashCode} for a sequence of longs, in big-endian order.
60    */
toHashCode(long... longs)61   private static HashCode toHashCode(long... longs) {
62     ByteBuffer bb = ByteBuffer.wrap(new byte[longs.length * 8]).order(ByteOrder.LITTLE_ENDIAN);
63     for (long x : longs) {
64       bb.putLong(x);
65     }
66     return HashCode.fromBytes(bb.array());
67   }
68 
testParanoid()69   public void testParanoid() {
70     HashFn hf = new HashFn() {
71       @Override public byte[] hash(byte[] input, int seed) {
72         Hasher hasher = murmur3_128(seed).newHasher();
73         Funnels.byteArrayFunnel().funnel(input, hasher);
74         return hasher.hash().asBytes();
75       }
76     };
77     // Murmur3F, MurmurHash3 for x64, 128-bit (MurmurHash3_x64_128)
78     // From http://code.google.com/p/smhasher/source/browse/trunk/main.cpp
79     HashTestUtils.verifyHashFunction(hf, 128, 0x6384BA69);
80   }
81 
testInvariants()82   public void testInvariants() {
83     HashTestUtils.assertInvariants(murmur3_128());
84   }
85 }
86