1 // Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
2 // This source code is licensed under both the GPLv2 (found in the
3 // COPYING file in the root directory) and Apache 2.0 License
4 // (found in the LICENSE.Apache file in the root directory).
5 //
6 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
7 // Use of this source code is governed by a BSD-style license that can be
8 // found in the LICENSE file. See the AUTHORS file for names of contributors.
9 #include "util/crc32c.h"
10 #include "test_util/testharness.h"
11 #include "util/coding.h"
12
13 namespace ROCKSDB_NAMESPACE {
14 namespace crc32c {
15
16 class CRC { };
17
18
19 // Tests for 3-way crc32c algorithm. We need these tests because it uses
20 // different lookup tables than the original Fast_CRC32
21 const unsigned int BUFFER_SIZE = 512 * 1024 * sizeof(uint64_t);
22 char buffer[BUFFER_SIZE];
23
24 struct ExpectedResult {
25 size_t offset;
26 size_t length;
27 uint32_t crc32c;
28 };
29
30 ExpectedResult expectedResults[] = {
31 // Zero-byte input
32 { 0, 0, ~0U },
33 // Small aligned inputs to test special cases in SIMD implementations
34 { 8, 1, 1543413366 },
35 { 8, 2, 523493126 },
36 { 8, 3, 1560427360 },
37 { 8, 4, 3422504776 },
38 { 8, 5, 447841138 },
39 { 8, 6, 3910050499 },
40 { 8, 7, 3346241981 },
41 // Small unaligned inputs
42 { 9, 1, 3855826643 },
43 { 10, 2, 560880875 },
44 { 11, 3, 1479707779 },
45 { 12, 4, 2237687071 },
46 { 13, 5, 4063855784 },
47 { 14, 6, 2553454047 },
48 { 15, 7, 1349220140 },
49 // Larger inputs to test leftover chunks at the end of aligned blocks
50 { 8, 8, 627613930 },
51 { 8, 9, 2105929409 },
52 { 8, 10, 2447068514 },
53 { 8, 11, 863807079 },
54 { 8, 12, 292050879 },
55 { 8, 13, 1411837737 },
56 { 8, 14, 2614515001 },
57 { 8, 15, 3579076296 },
58 { 8, 16, 2897079161 },
59 { 8, 17, 675168386 },
60 // // Much larger inputs
61 { 0, BUFFER_SIZE, 2096790750 },
62 { 1, BUFFER_SIZE / 2, 3854797577 },
63
64 };
65
TEST(CRC,StandardResults)66 TEST(CRC, StandardResults) {
67
68 // Original Fast_CRC32 tests.
69 // From rfc3720 section B.4.
70 char buf[32];
71
72 memset(buf, 0, sizeof(buf));
73 ASSERT_EQ(0x8a9136aaU, Value(buf, sizeof(buf)));
74
75 memset(buf, 0xff, sizeof(buf));
76 ASSERT_EQ(0x62a8ab43U, Value(buf, sizeof(buf)));
77
78 for (int i = 0; i < 32; i++) {
79 buf[i] = static_cast<char>(i);
80 }
81 ASSERT_EQ(0x46dd794eU, Value(buf, sizeof(buf)));
82
83 for (int i = 0; i < 32; i++) {
84 buf[i] = static_cast<char>(31 - i);
85 }
86 ASSERT_EQ(0x113fdb5cU, Value(buf, sizeof(buf)));
87
88 unsigned char data[48] = {
89 0x01, 0xc0, 0x00, 0x00,
90 0x00, 0x00, 0x00, 0x00,
91 0x00, 0x00, 0x00, 0x00,
92 0x00, 0x00, 0x00, 0x00,
93 0x14, 0x00, 0x00, 0x00,
94 0x00, 0x00, 0x04, 0x00,
95 0x00, 0x00, 0x00, 0x14,
96 0x00, 0x00, 0x00, 0x18,
97 0x28, 0x00, 0x00, 0x00,
98 0x00, 0x00, 0x00, 0x00,
99 0x02, 0x00, 0x00, 0x00,
100 0x00, 0x00, 0x00, 0x00,
101 };
102 ASSERT_EQ(0xd9963a56, Value(reinterpret_cast<char*>(data), sizeof(data)));
103
104 // 3-Way Crc32c tests ported from folly.
105 // Test 1: single computation
106 for (auto expected : expectedResults) {
107 uint32_t result = Value(buffer + expected.offset, expected.length);
108 EXPECT_EQ(~expected.crc32c, result);
109 }
110
111 // Test 2: stitching two computations
112 for (auto expected : expectedResults) {
113 size_t partialLength = expected.length / 2;
114 uint32_t partialChecksum = Value(buffer + expected.offset, partialLength);
115 uint32_t result = Extend(partialChecksum,
116 buffer + expected.offset + partialLength,
117 expected.length - partialLength);
118 EXPECT_EQ(~expected.crc32c, result);
119 }
120
121 }
122
TEST(CRC,Values)123 TEST(CRC, Values) {
124 ASSERT_NE(Value("a", 1), Value("foo", 3));
125 }
126
TEST(CRC,Extend)127 TEST(CRC, Extend) {
128 ASSERT_EQ(Value("hello world", 11),
129 Extend(Value("hello ", 6), "world", 5));
130 }
131
TEST(CRC,Mask)132 TEST(CRC, Mask) {
133 uint32_t crc = Value("foo", 3);
134 ASSERT_NE(crc, Mask(crc));
135 ASSERT_NE(crc, Mask(Mask(crc)));
136 ASSERT_EQ(crc, Unmask(Mask(crc)));
137 ASSERT_EQ(crc, Unmask(Unmask(Mask(Mask(crc)))));
138 }
139
140 } // namespace crc32c
141 } // namespace ROCKSDB_NAMESPACE
142
143 // copied from folly
144 const uint64_t FNV_64_HASH_START = 14695981039346656037ULL;
fnv64_buf(const void * buf,size_t n,uint64_t hash=FNV_64_HASH_START)145 inline uint64_t fnv64_buf(const void* buf,
146 size_t n,
147 uint64_t hash = FNV_64_HASH_START) {
148 // forcing signed char, since other platforms can use unsigned
149 const signed char* char_buf = reinterpret_cast<const signed char*>(buf);
150
151 for (size_t i = 0; i < n; ++i) {
152 hash += (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) +
153 (hash << 8) + (hash << 40);
154 hash ^= char_buf[i];
155 }
156 return hash;
157 }
158
main(int argc,char ** argv)159 int main(int argc, char** argv) {
160 ::testing::InitGoogleTest(&argc, argv);
161
162 // Populate a buffer with a deterministic pattern
163 // on which to compute checksums
164
165 const uint8_t* src = (uint8_t*)ROCKSDB_NAMESPACE::crc32c::buffer;
166 uint64_t* dst = (uint64_t*)ROCKSDB_NAMESPACE::crc32c::buffer;
167 const uint64_t* end =
168 (const uint64_t*)(ROCKSDB_NAMESPACE::crc32c::buffer +
169 ROCKSDB_NAMESPACE::crc32c::BUFFER_SIZE);
170 *dst++ = 0;
171 while (dst < end) {
172 ROCKSDB_NAMESPACE::EncodeFixed64(
173 reinterpret_cast<char*>(dst),
174 fnv64_buf((const char*)src, sizeof(uint64_t)));
175 dst++;
176 src += sizeof(uint64_t);
177 }
178
179 return RUN_ALL_TESTS();
180 }
181