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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.HashTestUtils.ascii;
20 import static com.google.common.hash.HashTestUtils.toBytes;
21 import static com.google.common.hash.Hashing.murmur3_128;
22 import static java.nio.ByteOrder.LITTLE_ENDIAN;
23 
24 import com.google.common.hash.Funnels;
25 import com.google.common.hash.HashTestUtils.HashFn;
26 
27 import junit.framework.TestCase;
28 
29 import java.util.Arrays;
30 
31 /**
32  * Tests for Murmur3Hash128.
33  */
34 public class Murmur3Hash128Test extends TestCase {
testCompatibilityWithCPlusPlus()35   public void testCompatibilityWithCPlusPlus() {
36     assertHash(0, toBytes(LITTLE_ENDIAN, 0x629942693e10f867L, 0x92db0b82baeb5347L),
37         ascii("hell"));
38     assertHash(1, toBytes(LITTLE_ENDIAN, 0xa78ddff5adae8d10L, 0x128900ef20900135L),
39         ascii("hello"));
40     assertHash(2, toBytes(LITTLE_ENDIAN, 0x8a486b23f422e826L, 0xf962a2c58947765fL),
41         ascii("hello "));
42     assertHash(3, toBytes(LITTLE_ENDIAN, 0x2ea59f466f6bed8cL, 0xc610990acc428a17L),
43         ascii("hello w"));
44     assertHash(4, toBytes(LITTLE_ENDIAN, 0x79f6305a386c572cL, 0x46305aed3483b94eL),
45         ascii("hello wo"));
46     assertHash(5, toBytes(LITTLE_ENDIAN, 0xc2219d213ec1f1b5L, 0xa1d8e2e0a52785bdL),
47         ascii("hello wor"));
48     assertHash(0, toBytes(LITTLE_ENDIAN, 0xe34bbc7bbc071b6cL, 0x7a433ca9c49a9347L),
49         ascii("The quick brown fox jumps over the lazy dog"));
50     assertHash(0, toBytes(LITTLE_ENDIAN, 0x658ca970ff85269aL, 0x43fee3eaa68e5c3eL),
51         ascii("The quick brown fox jumps over the lazy cog"));
52   }
53 
assertHash(int seed, byte[] expectedHash, byte[] input)54   private static void assertHash(int seed, byte[] expectedHash, byte[] input) {
55     byte[] hash = murmur3_128(seed).newHasher().putBytes(input).hash().asBytes();
56     assertTrue(Arrays.equals(expectedHash, hash));
57   }
58 
testParanoid()59   public void testParanoid() {
60     HashFn hf = new HashFn() {
61       @Override public byte[] hash(byte[] input, int seed) {
62         Hasher hasher = murmur3_128(seed).newHasher();
63         Funnels.byteArrayFunnel().funnel(input, hasher);
64         return hasher.hash().asBytes();
65       }
66     };
67     // the magic number comes from:
68     // http://code.google.com/p/smhasher/source/browse/trunk/main.cpp, #74
69     HashTestUtils.verifyHashFunction(hf, 128, 0x6384BA69);
70   }
71 }
72