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) 2012 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
10 #include "util/hash.h"
11
12 #include <cstring>
13 #include <vector>
14
15 #include "test_util/testharness.h"
16 #include "util/coding.h"
17 #include "util/coding_lean.h"
18 #include "util/hash128.h"
19 #include "util/math128.h"
20
21 using ROCKSDB_NAMESPACE::BijectiveHash2x64;
22 using ROCKSDB_NAMESPACE::BijectiveUnhash2x64;
23 using ROCKSDB_NAMESPACE::DecodeFixed64;
24 using ROCKSDB_NAMESPACE::EncodeFixed32;
25 using ROCKSDB_NAMESPACE::GetSliceHash64;
26 using ROCKSDB_NAMESPACE::Hash;
27 using ROCKSDB_NAMESPACE::Hash128;
28 using ROCKSDB_NAMESPACE::Hash2x64;
29 using ROCKSDB_NAMESPACE::Hash64;
30 using ROCKSDB_NAMESPACE::Lower32of64;
31 using ROCKSDB_NAMESPACE::Lower64of128;
32 using ROCKSDB_NAMESPACE::Slice;
33 using ROCKSDB_NAMESPACE::Unsigned128;
34 using ROCKSDB_NAMESPACE::Upper32of64;
35 using ROCKSDB_NAMESPACE::Upper64of128;
36
37 // The hash algorithm is part of the file format, for example for the Bloom
38 // filters. Test that the hash values are stable for a set of random strings of
39 // varying lengths.
TEST(HashTest,Values)40 TEST(HashTest, Values) {
41 constexpr uint32_t kSeed = 0xbc9f1d34; // Same as BloomHash.
42
43 EXPECT_EQ(Hash("", 0, kSeed), 3164544308u);
44 EXPECT_EQ(Hash("\x08", 1, kSeed), 422599524u);
45 EXPECT_EQ(Hash("\x17", 1, kSeed), 3168152998u);
46 EXPECT_EQ(Hash("\x9a", 1, kSeed), 3195034349u);
47 EXPECT_EQ(Hash("\x1c", 1, kSeed), 2651681383u);
48 EXPECT_EQ(Hash("\x4d\x76", 2, kSeed), 2447836956u);
49 EXPECT_EQ(Hash("\x52\xd5", 2, kSeed), 3854228105u);
50 EXPECT_EQ(Hash("\x91\xf7", 2, kSeed), 31066776u);
51 EXPECT_EQ(Hash("\xd6\x27", 2, kSeed), 1806091603u);
52 EXPECT_EQ(Hash("\x30\x46\x0b", 3, kSeed), 3808221797u);
53 EXPECT_EQ(Hash("\x56\xdc\xd6", 3, kSeed), 2157698265u);
54 EXPECT_EQ(Hash("\xd4\x52\x33", 3, kSeed), 1721992661u);
55 EXPECT_EQ(Hash("\x6a\xb5\xf4", 3, kSeed), 2469105222u);
56 EXPECT_EQ(Hash("\x67\x53\x81\x1c", 4, kSeed), 118283265u);
57 EXPECT_EQ(Hash("\x69\xb8\xc0\x88", 4, kSeed), 3416318611u);
58 EXPECT_EQ(Hash("\x1e\x84\xaf\x2d", 4, kSeed), 3315003572u);
59 EXPECT_EQ(Hash("\x46\xdc\x54\xbe", 4, kSeed), 447346355u);
60 EXPECT_EQ(Hash("\xd0\x7a\x6e\xea\x56", 5, kSeed), 4255445370u);
61 EXPECT_EQ(Hash("\x86\x83\xd5\xa4\xd8", 5, kSeed), 2390603402u);
62 EXPECT_EQ(Hash("\xb7\x46\xbb\x77\xce", 5, kSeed), 2048907743u);
63 EXPECT_EQ(Hash("\x6c\xa8\xbc\xe5\x99", 5, kSeed), 2177978500u);
64 EXPECT_EQ(Hash("\x5c\x5e\xe1\xa0\x73\x81", 6, kSeed), 1036846008u);
65 EXPECT_EQ(Hash("\x08\x5d\x73\x1c\xe5\x2e", 6, kSeed), 229980482u);
66 EXPECT_EQ(Hash("\x42\xfb\xf2\x52\xb4\x10", 6, kSeed), 3655585422u);
67 EXPECT_EQ(Hash("\x73\xe1\xff\x56\x9c\xce", 6, kSeed), 3502708029u);
68 EXPECT_EQ(Hash("\x5c\xbe\x97\x75\x54\x9a\x52", 7, kSeed), 815120748u);
69 EXPECT_EQ(Hash("\x16\x82\x39\x49\x88\x2b\x36", 7, kSeed), 3056033698u);
70 EXPECT_EQ(Hash("\x59\x77\xf0\xa7\x24\xf4\x78", 7, kSeed), 587205227u);
71 EXPECT_EQ(Hash("\xd3\xa5\x7c\x0e\xc0\x02\x07", 7, kSeed), 2030937252u);
72 EXPECT_EQ(Hash("\x31\x1b\x98\x75\x96\x22\xd3\x9a", 8, kSeed), 469635402u);
73 EXPECT_EQ(Hash("\x38\xd6\xf7\x28\x20\xb4\x8a\xe9", 8, kSeed), 3530274698u);
74 EXPECT_EQ(Hash("\xbb\x18\x5d\xf4\x12\x03\xf7\x99", 8, kSeed), 1974545809u);
75 EXPECT_EQ(Hash("\x80\xd4\x3b\x3b\xae\x22\xa2\x78", 8, kSeed), 3563570120u);
76 EXPECT_EQ(Hash("\x1a\xb5\xd0\xfe\xab\xc3\x61\xb2\x99", 9, kSeed),
77 2706087434u);
78 EXPECT_EQ(Hash("\x8e\x4a\xc3\x18\x20\x2f\x06\xe6\x3c", 9, kSeed),
79 1534654151u);
80 EXPECT_EQ(Hash("\xb6\xc0\xdd\x05\x3f\xc4\x86\x4c\xef", 9, kSeed),
81 2355554696u);
82 EXPECT_EQ(Hash("\x9a\x5f\x78\x0d\xaf\x50\xe1\x1f\x55", 9, kSeed),
83 1400800912u);
84 EXPECT_EQ(Hash("\x22\x6f\x39\x1f\xf8\xdd\x4f\x52\x17\x94", 10, kSeed),
85 3420325137u);
86 EXPECT_EQ(Hash("\x32\x89\x2a\x75\x48\x3a\x4a\x02\x69\xdd", 10, kSeed),
87 3427803584u);
88 EXPECT_EQ(Hash("\x06\x92\x5c\xf4\x88\x0e\x7e\x68\x38\x3e", 10, kSeed),
89 1152407945u);
90 EXPECT_EQ(Hash("\xbd\x2c\x63\x38\xbf\xe9\x78\xb7\xbf\x15", 10, kSeed),
91 3382479516u);
92 }
93
94 // The hash algorithm is part of the file format, for example for the Bloom
95 // filters.
TEST(HashTest,Hash64Misc)96 TEST(HashTest, Hash64Misc) {
97 constexpr uint32_t kSeed = 0; // Same as GetSliceHash64
98
99 for (char fill : {'\0', 'a', '1', '\xff'}) {
100 const size_t max_size = 1000;
101 const std::string str(max_size, fill);
102
103 for (size_t size = 0; size <= max_size; ++size) {
104 uint64_t here = Hash64(str.data(), size, kSeed);
105
106 // Must be same as unseeded Hash64 and GetSliceHash64
107 EXPECT_EQ(here, Hash64(str.data(), size));
108 EXPECT_EQ(here, GetSliceHash64(Slice(str.data(), size)));
109
110 // Upper and Lower must reconstruct hash
111 EXPECT_EQ(here, (uint64_t{Upper32of64(here)} << 32) | Lower32of64(here));
112 EXPECT_EQ(here, (uint64_t{Upper32of64(here)} << 32) + Lower32of64(here));
113 EXPECT_EQ(here, (uint64_t{Upper32of64(here)} << 32) ^ Lower32of64(here));
114
115 // Seed changes hash value (with high probability)
116 for (uint64_t var_seed = 1; var_seed != 0; var_seed <<= 1) {
117 EXPECT_NE(here, Hash64(str.data(), size, var_seed));
118 }
119
120 // Size changes hash value (with high probability)
121 size_t max_smaller_by = std::min(size_t{30}, size);
122 for (size_t smaller_by = 1; smaller_by <= max_smaller_by; ++smaller_by) {
123 EXPECT_NE(here, Hash64(str.data(), size - smaller_by, kSeed));
124 }
125 }
126 }
127 }
128
129 // Test that hash values are "non-trivial" for "trivial" inputs
TEST(HashTest,Hash64Trivial)130 TEST(HashTest, Hash64Trivial) {
131 // Thorough test too slow for regression testing
132 constexpr bool thorough = false;
133
134 // For various seeds, make sure hash of empty string is not zero.
135 constexpr uint64_t max_seed = thorough ? 0x1000000 : 0x10000;
136 for (uint64_t seed = 0; seed < max_seed; ++seed) {
137 uint64_t here = Hash64("", 0, seed);
138 EXPECT_NE(Lower32of64(here), 0u);
139 EXPECT_NE(Upper32of64(here), 0u);
140 }
141
142 // For standard seed, make sure hash of small strings are not zero
143 constexpr uint32_t kSeed = 0; // Same as GetSliceHash64
144 char input[4];
145 constexpr int max_len = thorough ? 3 : 2;
146 for (int len = 1; len <= max_len; ++len) {
147 for (uint32_t i = 0; (i >> (len * 8)) == 0; ++i) {
148 EncodeFixed32(input, i);
149 uint64_t here = Hash64(input, len, kSeed);
150 EXPECT_NE(Lower32of64(here), 0u);
151 EXPECT_NE(Upper32of64(here), 0u);
152 }
153 }
154 }
155
156 // Test that the hash values are stable for a set of random strings of
157 // varying small lengths.
TEST(HashTest,Hash64SmallValueSchema)158 TEST(HashTest, Hash64SmallValueSchema) {
159 constexpr uint32_t kSeed = 0; // Same as GetSliceHash64
160
161 EXPECT_EQ(Hash64("", 0, kSeed), uint64_t{5999572062939766020u});
162 EXPECT_EQ(Hash64("\x08", 1, kSeed), uint64_t{583283813901344696u});
163 EXPECT_EQ(Hash64("\x17", 1, kSeed), uint64_t{16175549975585474943u});
164 EXPECT_EQ(Hash64("\x9a", 1, kSeed), uint64_t{16322991629225003903u});
165 EXPECT_EQ(Hash64("\x1c", 1, kSeed), uint64_t{13269285487706833447u});
166 EXPECT_EQ(Hash64("\x4d\x76", 2, kSeed), uint64_t{6859542833406258115u});
167 EXPECT_EQ(Hash64("\x52\xd5", 2, kSeed), uint64_t{4919611532550636959u});
168 EXPECT_EQ(Hash64("\x91\xf7", 2, kSeed), uint64_t{14199427467559720719u});
169 EXPECT_EQ(Hash64("\xd6\x27", 2, kSeed), uint64_t{12292689282614532691u});
170 EXPECT_EQ(Hash64("\x30\x46\x0b", 3, kSeed), uint64_t{11404699285340020889u});
171 EXPECT_EQ(Hash64("\x56\xdc\xd6", 3, kSeed), uint64_t{12404347133785524237u});
172 EXPECT_EQ(Hash64("\xd4\x52\x33", 3, kSeed), uint64_t{15853805298481534034u});
173 EXPECT_EQ(Hash64("\x6a\xb5\xf4", 3, kSeed), uint64_t{16863488758399383382u});
174 EXPECT_EQ(Hash64("\x67\x53\x81\x1c", 4, kSeed),
175 uint64_t{9010661983527562386u});
176 EXPECT_EQ(Hash64("\x69\xb8\xc0\x88", 4, kSeed),
177 uint64_t{6611781377647041447u});
178 EXPECT_EQ(Hash64("\x1e\x84\xaf\x2d", 4, kSeed),
179 uint64_t{15290969111616346501u});
180 EXPECT_EQ(Hash64("\x46\xdc\x54\xbe", 4, kSeed),
181 uint64_t{7063754590279313623u});
182 EXPECT_EQ(Hash64("\xd0\x7a\x6e\xea\x56", 5, kSeed),
183 uint64_t{6384167718754869899u});
184 EXPECT_EQ(Hash64("\x86\x83\xd5\xa4\xd8", 5, kSeed),
185 uint64_t{16874407254108011067u});
186 EXPECT_EQ(Hash64("\xb7\x46\xbb\x77\xce", 5, kSeed),
187 uint64_t{16809880630149135206u});
188 EXPECT_EQ(Hash64("\x6c\xa8\xbc\xe5\x99", 5, kSeed),
189 uint64_t{1249038833153141148u});
190 EXPECT_EQ(Hash64("\x5c\x5e\xe1\xa0\x73\x81", 6, kSeed),
191 uint64_t{17358142495308219330u});
192 EXPECT_EQ(Hash64("\x08\x5d\x73\x1c\xe5\x2e", 6, kSeed),
193 uint64_t{4237646583134806322u});
194 EXPECT_EQ(Hash64("\x42\xfb\xf2\x52\xb4\x10", 6, kSeed),
195 uint64_t{4373664924115234051u});
196 EXPECT_EQ(Hash64("\x73\xe1\xff\x56\x9c\xce", 6, kSeed),
197 uint64_t{12012981210634596029u});
198 EXPECT_EQ(Hash64("\x5c\xbe\x97\x75\x54\x9a\x52", 7, kSeed),
199 uint64_t{5716522398211028826u});
200 EXPECT_EQ(Hash64("\x16\x82\x39\x49\x88\x2b\x36", 7, kSeed),
201 uint64_t{15604531309862565013u});
202 EXPECT_EQ(Hash64("\x59\x77\xf0\xa7\x24\xf4\x78", 7, kSeed),
203 uint64_t{8601330687345614172u});
204 EXPECT_EQ(Hash64("\xd3\xa5\x7c\x0e\xc0\x02\x07", 7, kSeed),
205 uint64_t{8088079329364056942u});
206 EXPECT_EQ(Hash64("\x31\x1b\x98\x75\x96\x22\xd3\x9a", 8, kSeed),
207 uint64_t{9844314944338447628u});
208 EXPECT_EQ(Hash64("\x38\xd6\xf7\x28\x20\xb4\x8a\xe9", 8, kSeed),
209 uint64_t{10973293517982163143u});
210 EXPECT_EQ(Hash64("\xbb\x18\x5d\xf4\x12\x03\xf7\x99", 8, kSeed),
211 uint64_t{9986007080564743219u});
212 EXPECT_EQ(Hash64("\x80\xd4\x3b\x3b\xae\x22\xa2\x78", 8, kSeed),
213 uint64_t{1729303145008254458u});
214 EXPECT_EQ(Hash64("\x1a\xb5\xd0\xfe\xab\xc3\x61\xb2\x99", 9, kSeed),
215 uint64_t{13253403748084181481u});
216 EXPECT_EQ(Hash64("\x8e\x4a\xc3\x18\x20\x2f\x06\xe6\x3c", 9, kSeed),
217 uint64_t{7768754303876232188u});
218 EXPECT_EQ(Hash64("\xb6\xc0\xdd\x05\x3f\xc4\x86\x4c\xef", 9, kSeed),
219 uint64_t{12439346786701492u});
220 EXPECT_EQ(Hash64("\x9a\x5f\x78\x0d\xaf\x50\xe1\x1f\x55", 9, kSeed),
221 uint64_t{10841838338450144690u});
222 EXPECT_EQ(Hash64("\x22\x6f\x39\x1f\xf8\xdd\x4f\x52\x17\x94", 10, kSeed),
223 uint64_t{12883919702069153152u});
224 EXPECT_EQ(Hash64("\x32\x89\x2a\x75\x48\x3a\x4a\x02\x69\xdd", 10, kSeed),
225 uint64_t{12692903507676842188u});
226 EXPECT_EQ(Hash64("\x06\x92\x5c\xf4\x88\x0e\x7e\x68\x38\x3e", 10, kSeed),
227 uint64_t{6540985900674032620u});
228 EXPECT_EQ(Hash64("\xbd\x2c\x63\x38\xbf\xe9\x78\xb7\xbf\x15", 10, kSeed),
229 uint64_t{10551812464348219044u});
230 }
231
Hash64TestDescriptor(const char * repeat,size_t limit)232 std::string Hash64TestDescriptor(const char *repeat, size_t limit) {
233 const char *mod61_encode =
234 "abcdefghijklmnopqrstuvwxyz123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
235
236 std::string input;
237 while (input.size() < limit) {
238 input.append(repeat);
239 }
240 std::string rv;
241 for (size_t i = 0; i < limit; ++i) {
242 uint64_t h = GetSliceHash64(Slice(input.data(), i));
243 rv.append(1, mod61_encode[static_cast<size_t>(h % 61)]);
244 }
245 return rv;
246 }
247
248 // XXPH3 changes its algorithm for various sizes up through 250 bytes, so
249 // we need to check the stability of larger sizes also.
TEST(HashTest,Hash64LargeValueSchema)250 TEST(HashTest, Hash64LargeValueSchema) {
251 // Each of these derives a "descriptor" from the hash values for all
252 // lengths up to 430.
253 // Note that "c" is common for the zero-length string.
254 EXPECT_EQ(
255 Hash64TestDescriptor("foo", 430),
256 "cRhyWsY67B6klRA1udmOuiYuX7IthyGBKqbeosz2hzVglWCmQx8nEdnpkvPfYX56Up2OWOTV"
257 "lTzfAoYwvtqKzjD8E9xttR2unelbXbIV67NUe6bOO23BxaSFRcA3njGu5cUWfgwOqNoTsszp"
258 "uPvKRP6qaUR5VdoBkJUCFIefd7edlNK5mv6JYWaGdwxehg65hTkTmjZoPKxTZo4PLyzbL9U4"
259 "xt12ITSfeP2MfBHuLI2z2pDlBb44UQKVMx27LEoAHsdLp3WfWfgH3sdRBRCHm33UxCM4QmE2"
260 "xJ7gqSvNwTeH7v9GlC8zWbGroyD3UVNeShMLx29O7tH1biemLULwAHyIw8zdtLMDpEJ8m2ic"
261 "l6Lb4fDuuFNAs1GCVUthjK8CV8SWI8Rsz5THSwn5CGhpqUwSZcFknjwWIl5rNCvDxXJqYr");
262 // Note that "1EeRk" is common for "Rocks"
263 EXPECT_EQ(
264 Hash64TestDescriptor("Rocks", 430),
265 "c1EeRkrzgOYWLA8PuhJrwTePJewoB44WdXYDfhbk3ZxTqqg25WlPExDl7IKIQLJvnA6gJxxn"
266 "9TCSLkFGfJeXehaSS1GBqWSzfhEH4VXiXIUCuxJXxtKXcSC6FrNIQGTZbYDiUOLD6Y5inzrF"
267 "9etwQhXUBanw55xAUdNMFQAm2GjJ6UDWp2mISLiMMkLjANWMKLaZMqaFLX37qB4MRO1ooVRv"
268 "zSvaNRSCLxlggQCasQq8icWjzf3HjBlZtU6pd4rkaUxSzHqmo9oM5MghbU5Rtxg8wEfO7lVN"
269 "5wdMONYecslQTwjZUpO1K3LDf3K3XK6sUXM6ShQQ3RHmMn2acB4YtTZ3QQcHYJSOHn2DuWpa"
270 "Q8RqzX5lab92YmOLaCdOHq1BPsM7SIBzMdLgePNsJ1vvMALxAaoDUHPxoFLO2wx18IXnyX");
271 EXPECT_EQ(
272 Hash64TestDescriptor("RocksDB", 430),
273 "c1EeRkukbkb28wLTahwD2sfUhZzaBEnF8SVrxnPVB6A7b8CaAl3UKsDZISF92GSq2wDCukOq"
274 "Jgrsp7A3KZhDiLW8dFXp8UPqPxMCRlMdZeVeJ2dJxrmA6cyt99zkQFj7ELbut6jAeVqARFnw"
275 "fnWVXOsaLrq7bDCbMcns2DKvTaaqTCLMYxI7nhtLpFN1jR755FRQFcOzrrDbh7QhypjdvlYw"
276 "cdAMSZgp9JMHxbM23wPSuH6BOFgxejz35PScZfhDPvTOxIy1jc3MZsWrMC3P324zNolO7JdW"
277 "CX2I5UDKjjaEJfxbgVgJIXxtQGlmj2xkO5sPpjULQV4X2HlY7FQleJ4QRaJIB4buhCA4vUTF"
278 "eMFlxCIYUpTCsal2qsmnGOWa8WCcefrohMjDj1fjzSvSaQwlpyR1GZHF2uPOoQagiCpHpm");
279 }
280
TEST(HashTest,Hash128Misc)281 TEST(HashTest, Hash128Misc) {
282 constexpr uint32_t kSeed = 0; // Same as GetSliceHash128
283
284 for (char fill : {'\0', 'a', '1', '\xff', 'e'}) {
285 const size_t max_size = 1000;
286 std::string str(max_size, fill);
287
288 if (fill == 'e') {
289 // Use different characters to check endianness handling
290 for (size_t i = 0; i < str.size(); ++i) {
291 str[i] += static_cast<char>(i);
292 }
293 }
294
295 for (size_t size = 0; size <= max_size; ++size) {
296 Unsigned128 here = Hash128(str.data(), size, kSeed);
297
298 // Must be same as unseeded Hash128 and GetSliceHash128
299 EXPECT_EQ(here, Hash128(str.data(), size));
300 EXPECT_EQ(here, GetSliceHash128(Slice(str.data(), size)));
301 {
302 uint64_t hi, lo;
303 Hash2x64(str.data(), size, &hi, &lo);
304 EXPECT_EQ(Lower64of128(here), lo);
305 EXPECT_EQ(Upper64of128(here), hi);
306 }
307 if (size == 16) {
308 const uint64_t in_hi = DecodeFixed64(str.data() + 8);
309 const uint64_t in_lo = DecodeFixed64(str.data());
310 uint64_t hi, lo;
311 BijectiveHash2x64(in_hi, in_lo, &hi, &lo);
312 EXPECT_EQ(Lower64of128(here), lo);
313 EXPECT_EQ(Upper64of128(here), hi);
314 uint64_t un_hi, un_lo;
315 BijectiveUnhash2x64(hi, lo, &un_hi, &un_lo);
316 EXPECT_EQ(in_lo, un_lo);
317 EXPECT_EQ(in_hi, un_hi);
318 }
319
320 // Upper and Lower must reconstruct hash
321 EXPECT_EQ(here,
322 (Unsigned128{Upper64of128(here)} << 64) | Lower64of128(here));
323 EXPECT_EQ(here,
324 (Unsigned128{Upper64of128(here)} << 64) ^ Lower64of128(here));
325
326 // Seed changes hash value (with high probability)
327 for (uint64_t var_seed = 1; var_seed != 0; var_seed <<= 1) {
328 Unsigned128 seeded = Hash128(str.data(), size, var_seed);
329 EXPECT_NE(here, seeded);
330 // Must match seeded Hash2x64
331 {
332 uint64_t hi, lo;
333 Hash2x64(str.data(), size, var_seed, &hi, &lo);
334 EXPECT_EQ(Lower64of128(seeded), lo);
335 EXPECT_EQ(Upper64of128(seeded), hi);
336 }
337 if (size == 16) {
338 const uint64_t in_hi = DecodeFixed64(str.data() + 8);
339 const uint64_t in_lo = DecodeFixed64(str.data());
340 uint64_t hi, lo;
341 BijectiveHash2x64(in_hi, in_lo, var_seed, &hi, &lo);
342 EXPECT_EQ(Lower64of128(seeded), lo);
343 EXPECT_EQ(Upper64of128(seeded), hi);
344 uint64_t un_hi, un_lo;
345 BijectiveUnhash2x64(hi, lo, var_seed, &un_hi, &un_lo);
346 EXPECT_EQ(in_lo, un_lo);
347 EXPECT_EQ(in_hi, un_hi);
348 }
349 }
350
351 // Size changes hash value (with high probability)
352 size_t max_smaller_by = std::min(size_t{30}, size);
353 for (size_t smaller_by = 1; smaller_by <= max_smaller_by; ++smaller_by) {
354 EXPECT_NE(here, Hash128(str.data(), size - smaller_by, kSeed));
355 }
356 }
357 }
358 }
359
360 // Test that hash values are "non-trivial" for "trivial" inputs
TEST(HashTest,Hash128Trivial)361 TEST(HashTest, Hash128Trivial) {
362 // Thorough test too slow for regression testing
363 constexpr bool thorough = false;
364
365 // For various seeds, make sure hash of empty string is not zero.
366 constexpr uint64_t max_seed = thorough ? 0x1000000 : 0x10000;
367 for (uint64_t seed = 0; seed < max_seed; ++seed) {
368 Unsigned128 here = Hash128("", 0, seed);
369 EXPECT_NE(Lower64of128(here), 0u);
370 EXPECT_NE(Upper64of128(here), 0u);
371 }
372
373 // For standard seed, make sure hash of small strings are not zero
374 constexpr uint32_t kSeed = 0; // Same as GetSliceHash128
375 char input[4];
376 constexpr int max_len = thorough ? 3 : 2;
377 for (int len = 1; len <= max_len; ++len) {
378 for (uint32_t i = 0; (i >> (len * 8)) == 0; ++i) {
379 EncodeFixed32(input, i);
380 Unsigned128 here = Hash128(input, len, kSeed);
381 EXPECT_NE(Lower64of128(here), 0u);
382 EXPECT_NE(Upper64of128(here), 0u);
383 }
384 }
385 }
386
Hash128TestDescriptor(const char * repeat,size_t limit)387 std::string Hash128TestDescriptor(const char *repeat, size_t limit) {
388 const char *mod61_encode =
389 "abcdefghijklmnopqrstuvwxyz123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
390
391 std::string input;
392 while (input.size() < limit) {
393 input.append(repeat);
394 }
395 std::string rv;
396 for (size_t i = 0; i < limit; ++i) {
397 auto h = GetSliceHash128(Slice(input.data(), i));
398 uint64_t h2 = Upper64of128(h) + Lower64of128(h);
399 rv.append(1, mod61_encode[static_cast<size_t>(h2 % 61)]);
400 }
401 return rv;
402 }
403
404 // XXH3 changes its algorithm for various sizes up through 250 bytes, so
405 // we need to check the stability of larger sizes also.
TEST(HashTest,Hash128ValueSchema)406 TEST(HashTest, Hash128ValueSchema) {
407 // Each of these derives a "descriptor" from the hash values for all
408 // lengths up to 430.
409 // Note that "b" is common for the zero-length string.
410 EXPECT_EQ(
411 Hash128TestDescriptor("foo", 430),
412 "bUMA3As8n9I4vNGhThXlEevxZlyMcbb6TYAlIKJ2f5ponsv99q962rYclQ7u3gfnRdCDQ5JI"
413 "2LrGUaCycbXrvLFe4SjgRb9RQwCfrnmNQ7VSEwSKMnkGCK3bDbXSrnIh5qLXdtvIZklbJpGH"
414 "Dqr93BlqF9ubTnOSYkSdx89XvQqflMIW8bjfQp9BPjQejWOeEQspnN1D3sfgVdFhpaQdHYA5"
415 "pI2XcPlCMFPxvrFuRr7joaDvjNe9IUZaunLPMewuXmC3EL95h52Ju3D7y9RNKhgYxMTrA84B"
416 "yJrMvyjdm3vlBxet4EN7v2GEyjbGuaZW9UL6lrX6PghJDg7ACfLGdxNbH3qXM4zaiG2RKnL5"
417 "S3WXKR78RBB5fRFQ8KDIEQjHFvSNsc3GrAEi6W8P2lv8JMTzjBODO2uN4wadVQFT9wpGfV");
418 // Note that "35D2v" is common for "Rocks"
419 EXPECT_EQ(
420 Hash128TestDescriptor("Rocks", 430),
421 "b35D2vzvklFVDqJmyLRXyApwGGO3EAT3swhe8XJAN3mY2UVPglzdmydxcba6JI2tSvwO6zSu"
422 "ANpjSM7tc9G5iMhsa7R8GfyCXRO1TnLg7HvdWNdgGGBirxZR68BgT7TQsYJt6zyEyISeXI1n"
423 "MXA48Xo7dWfJeYN6Z4KWlqZY7TgFXGbks9AX4ehZNSGtIhdO5i58qlgVX1bEejeOVaCcjC79"
424 "67DrMfOKds7rUQzjBa77sMPcoPW1vu6ljGJPZH3XkRyDMZ1twxXKkNxN3tE8nR7JHwyqBAxE"
425 "fTcjbOWrLZ1irWxRSombD8sGDEmclgF11IxqEhe3Rt7gyofO3nExGckKkS9KfRqsCHbiUyva"
426 "JGkJwUHRXaZnh58b4i1Ei9aQKZjXlvIVDixoZrjcNaH5XJIJlRZce9Z9t82wYapTpckYSg");
427 EXPECT_EQ(
428 Hash128TestDescriptor("RocksDB", 430),
429 "b35D2vFUst3XDZCRlSrhmYYakmqImV97LbBsV6EZlOEQpUPH1d1sD3xMKAPlA5UErHehg5O7"
430 "n966fZqhAf3hRc24kGCLfNAWjyUa7vSNOx3IcPoTyVRFZeFlcCtfl7t1QJumHOCpS33EBmBF"
431 "hvK13QjBbDWYWeHQhJhgV9Mqbx17TIcvUkEnYZxb8IzWNmjVsJG44Z7v52DjGj1ZzS62S2Vv"
432 "qWcDO7apvH5VHg68E9Wl6nXP21vlmUqEH9GeWRehfWVvY7mUpsAg5drHHQyDSdiMceiUuUxJ"
433 "XJqHFcDdzbbPk7xDvbLgWCKvH8k3MpQNWOmbSSRDdAP6nGlDjoTToYkcqVREHJzztSWAAq5h"
434 "GHSUNJ6OxsMHhf8EhXfHtKyUzRmPtjYyeckQcGmrQfFFLidc6cjMDKCdBG6c6HVBrS7H2R");
435 }
436
TEST(FastRange32Test,Values)437 TEST(FastRange32Test, Values) {
438 using ROCKSDB_NAMESPACE::FastRange32;
439 // Zero range
440 EXPECT_EQ(FastRange32(0, 0), 0U);
441 EXPECT_EQ(FastRange32(123, 0), 0U);
442 EXPECT_EQ(FastRange32(0xffffffff, 0), 0U);
443
444 // One range
445 EXPECT_EQ(FastRange32(0, 1), 0U);
446 EXPECT_EQ(FastRange32(123, 1), 0U);
447 EXPECT_EQ(FastRange32(0xffffffff, 1), 0U);
448
449 // Two range
450 EXPECT_EQ(FastRange32(0, 2), 0U);
451 EXPECT_EQ(FastRange32(123, 2), 0U);
452 EXPECT_EQ(FastRange32(0x7fffffff, 2), 0U);
453 EXPECT_EQ(FastRange32(0x80000000, 2), 1U);
454 EXPECT_EQ(FastRange32(0xffffffff, 2), 1U);
455
456 // Seven range
457 EXPECT_EQ(FastRange32(0, 7), 0U);
458 EXPECT_EQ(FastRange32(123, 7), 0U);
459 EXPECT_EQ(FastRange32(613566756, 7), 0U);
460 EXPECT_EQ(FastRange32(613566757, 7), 1U);
461 EXPECT_EQ(FastRange32(1227133513, 7), 1U);
462 EXPECT_EQ(FastRange32(1227133514, 7), 2U);
463 // etc.
464 EXPECT_EQ(FastRange32(0xffffffff, 7), 6U);
465
466 // Big
467 EXPECT_EQ(FastRange32(1, 0x80000000), 0U);
468 EXPECT_EQ(FastRange32(2, 0x80000000), 1U);
469 EXPECT_EQ(FastRange32(4, 0x7fffffff), 1U);
470 EXPECT_EQ(FastRange32(4, 0x80000000), 2U);
471 EXPECT_EQ(FastRange32(0xffffffff, 0x7fffffff), 0x7ffffffeU);
472 EXPECT_EQ(FastRange32(0xffffffff, 0x80000000), 0x7fffffffU);
473 }
474
TEST(FastRange64Test,Values)475 TEST(FastRange64Test, Values) {
476 using ROCKSDB_NAMESPACE::FastRange64;
477 // Zero range
478 EXPECT_EQ(FastRange64(0, 0), 0U);
479 EXPECT_EQ(FastRange64(123, 0), 0U);
480 EXPECT_EQ(FastRange64(0xffffFFFF, 0), 0U);
481 EXPECT_EQ(FastRange64(0xffffFFFFffffFFFF, 0), 0U);
482
483 // One range
484 EXPECT_EQ(FastRange64(0, 1), 0U);
485 EXPECT_EQ(FastRange64(123, 1), 0U);
486 EXPECT_EQ(FastRange64(0xffffFFFF, 1), 0U);
487 EXPECT_EQ(FastRange64(0xffffFFFFffffFFFF, 1), 0U);
488
489 // Two range
490 EXPECT_EQ(FastRange64(0, 2), 0U);
491 EXPECT_EQ(FastRange64(123, 2), 0U);
492 EXPECT_EQ(FastRange64(0xffffFFFF, 2), 0U);
493 EXPECT_EQ(FastRange64(0x7fffFFFFffffFFFF, 2), 0U);
494 EXPECT_EQ(FastRange64(0x8000000000000000, 2), 1U);
495 EXPECT_EQ(FastRange64(0xffffFFFFffffFFFF, 2), 1U);
496
497 // Seven range
498 EXPECT_EQ(FastRange64(0, 7), 0U);
499 EXPECT_EQ(FastRange64(123, 7), 0U);
500 EXPECT_EQ(FastRange64(0xffffFFFF, 7), 0U);
501 EXPECT_EQ(FastRange64(2635249153387078802, 7), 0U);
502 EXPECT_EQ(FastRange64(2635249153387078803, 7), 1U);
503 EXPECT_EQ(FastRange64(5270498306774157604, 7), 1U);
504 EXPECT_EQ(FastRange64(5270498306774157605, 7), 2U);
505 EXPECT_EQ(FastRange64(0x7fffFFFFffffFFFF, 7), 3U);
506 EXPECT_EQ(FastRange64(0x8000000000000000, 7), 3U);
507 EXPECT_EQ(FastRange64(0xffffFFFFffffFFFF, 7), 6U);
508
509 // Big but 32-bit range
510 EXPECT_EQ(FastRange64(0x100000000, 0x80000000), 0U);
511 EXPECT_EQ(FastRange64(0x200000000, 0x80000000), 1U);
512 EXPECT_EQ(FastRange64(0x400000000, 0x7fffFFFF), 1U);
513 EXPECT_EQ(FastRange64(0x400000000, 0x80000000), 2U);
514 EXPECT_EQ(FastRange64(0xffffFFFFffffFFFF, 0x7fffFFFF), 0x7fffFFFEU);
515 EXPECT_EQ(FastRange64(0xffffFFFFffffFFFF, 0x80000000), 0x7fffFFFFU);
516
517 // Big, > 32-bit range
518 #if SIZE_MAX == UINT64_MAX
519 EXPECT_EQ(FastRange64(0x7fffFFFFffffFFFF, 0x4200000002), 0x2100000000U);
520 EXPECT_EQ(FastRange64(0x8000000000000000, 0x4200000002), 0x2100000001U);
521
522 EXPECT_EQ(FastRange64(0x0000000000000000, 420000000002), 0U);
523 EXPECT_EQ(FastRange64(0x7fffFFFFffffFFFF, 420000000002), 210000000000U);
524 EXPECT_EQ(FastRange64(0x8000000000000000, 420000000002), 210000000001U);
525 EXPECT_EQ(FastRange64(0xffffFFFFffffFFFF, 420000000002), 420000000001U);
526
527 EXPECT_EQ(FastRange64(0xffffFFFFffffFFFF, 0xffffFFFFffffFFFF),
528 0xffffFFFFffffFFFEU);
529 #endif
530 }
531
TEST(FastRangeGenericTest,Values)532 TEST(FastRangeGenericTest, Values) {
533 using ROCKSDB_NAMESPACE::FastRangeGeneric;
534 // Generic (including big and small)
535 // Note that FastRangeGeneric is also tested indirectly above via
536 // FastRange32 and FastRange64.
537 EXPECT_EQ(
538 FastRangeGeneric(uint64_t{0x8000000000000000}, uint64_t{420000000002}),
539 uint64_t{210000000001});
540 EXPECT_EQ(FastRangeGeneric(uint64_t{0x8000000000000000}, uint16_t{12468}),
541 uint16_t{6234});
542 EXPECT_EQ(FastRangeGeneric(uint32_t{0x80000000}, uint16_t{12468}),
543 uint16_t{6234});
544 // Not recommended for typical use because for example this could fail on
545 // some platforms and pass on others:
546 //EXPECT_EQ(FastRangeGeneric(static_cast<unsigned long>(0x80000000),
547 // uint16_t{12468}),
548 // uint16_t{6234});
549 }
550
551 // for inspection of disassembly
FastRange32(uint32_t hash,uint32_t range)552 uint32_t FastRange32(uint32_t hash, uint32_t range) {
553 return ROCKSDB_NAMESPACE::FastRange32(hash, range);
554 }
555
556 // for inspection of disassembly
FastRange64(uint64_t hash,size_t range)557 size_t FastRange64(uint64_t hash, size_t range) {
558 return ROCKSDB_NAMESPACE::FastRange64(hash, range);
559 }
560
561 // Tests for math.h / math128.h (not worth a separate test binary)
562 using ROCKSDB_NAMESPACE::BitParity;
563 using ROCKSDB_NAMESPACE::BitsSetToOne;
564 using ROCKSDB_NAMESPACE::CountTrailingZeroBits;
565 using ROCKSDB_NAMESPACE::DecodeFixed128;
566 using ROCKSDB_NAMESPACE::DecodeFixedGeneric;
567 using ROCKSDB_NAMESPACE::EncodeFixed128;
568 using ROCKSDB_NAMESPACE::EncodeFixedGeneric;
569 using ROCKSDB_NAMESPACE::FloorLog2;
570 using ROCKSDB_NAMESPACE::Lower64of128;
571 using ROCKSDB_NAMESPACE::Multiply64to128;
572 using ROCKSDB_NAMESPACE::Unsigned128;
573 using ROCKSDB_NAMESPACE::Upper64of128;
574
575 template <typename T>
test_BitOps()576 static void test_BitOps() {
577 // This complex code is to generalize to 128-bit values. Otherwise
578 // we could just use = static_cast<T>(0x5555555555555555ULL);
579 T everyOtherBit = 0;
580 for (unsigned i = 0; i < sizeof(T); ++i) {
581 everyOtherBit = (everyOtherBit << 8) | T{0x55};
582 }
583
584 // This one built using bit operations, as our 128-bit layer
585 // might not implement arithmetic such as subtraction.
586 T vm1 = 0; // "v minus one"
587
588 for (int i = 0; i < int{8 * sizeof(T)}; ++i) {
589 T v = T{1} << i;
590 // If we could directly use arithmetic:
591 // T vm1 = static_cast<T>(v - 1);
592
593 // FloorLog2
594 if (v > 0) {
595 EXPECT_EQ(FloorLog2(v), i);
596 }
597 if (vm1 > 0) {
598 EXPECT_EQ(FloorLog2(vm1), i - 1);
599 EXPECT_EQ(FloorLog2(everyOtherBit & vm1), (i - 1) & ~1);
600 }
601
602 // CountTrailingZeroBits
603 if (v != 0) {
604 EXPECT_EQ(CountTrailingZeroBits(v), i);
605 }
606 if (vm1 != 0) {
607 EXPECT_EQ(CountTrailingZeroBits(vm1), 0);
608 }
609 if (i < int{8 * sizeof(T)} - 1) {
610 EXPECT_EQ(CountTrailingZeroBits(~vm1 & everyOtherBit), (i + 1) & ~1);
611 }
612
613 // BitsSetToOne
614 EXPECT_EQ(BitsSetToOne(v), 1);
615 EXPECT_EQ(BitsSetToOne(vm1), i);
616 EXPECT_EQ(BitsSetToOne(vm1 & everyOtherBit), (i + 1) / 2);
617
618 // BitParity
619 EXPECT_EQ(BitParity(v), 1);
620 EXPECT_EQ(BitParity(vm1), i & 1);
621 EXPECT_EQ(BitParity(vm1 & everyOtherBit), ((i + 1) / 2) & 1);
622
623 vm1 = (vm1 << 1) | 1;
624 }
625 }
626
TEST(MathTest,BitOps)627 TEST(MathTest, BitOps) {
628 test_BitOps<uint32_t>();
629 test_BitOps<uint64_t>();
630 test_BitOps<uint16_t>();
631 test_BitOps<uint8_t>();
632 test_BitOps<unsigned char>();
633 test_BitOps<unsigned short>();
634 test_BitOps<unsigned int>();
635 test_BitOps<unsigned long>();
636 test_BitOps<unsigned long long>();
637 test_BitOps<char>();
638 test_BitOps<size_t>();
639 test_BitOps<int32_t>();
640 test_BitOps<int64_t>();
641 test_BitOps<int16_t>();
642 test_BitOps<int8_t>();
643 test_BitOps<signed char>();
644 test_BitOps<short>();
645 test_BitOps<int>();
646 test_BitOps<long>();
647 test_BitOps<long long>();
648 test_BitOps<ptrdiff_t>();
649 }
650
TEST(MathTest,BitOps128)651 TEST(MathTest, BitOps128) { test_BitOps<Unsigned128>(); }
652
TEST(MathTest,Math128)653 TEST(MathTest, Math128) {
654 const Unsigned128 sixteenHexOnes = 0x1111111111111111U;
655 const Unsigned128 thirtyHexOnes = (sixteenHexOnes << 56) | sixteenHexOnes;
656 const Unsigned128 sixteenHexTwos = 0x2222222222222222U;
657 const Unsigned128 thirtyHexTwos = (sixteenHexTwos << 56) | sixteenHexTwos;
658
659 // v will slide from all hex ones to all hex twos
660 Unsigned128 v = thirtyHexOnes;
661 for (int i = 0; i <= 30; ++i) {
662 // Test bitwise operations
663 EXPECT_EQ(BitsSetToOne(v), 30);
664 EXPECT_EQ(BitsSetToOne(~v), 128 - 30);
665 EXPECT_EQ(BitsSetToOne(v & thirtyHexOnes), 30 - i);
666 EXPECT_EQ(BitsSetToOne(v | thirtyHexOnes), 30 + i);
667 EXPECT_EQ(BitsSetToOne(v ^ thirtyHexOnes), 2 * i);
668 EXPECT_EQ(BitsSetToOne(v & thirtyHexTwos), i);
669 EXPECT_EQ(BitsSetToOne(v | thirtyHexTwos), 60 - i);
670 EXPECT_EQ(BitsSetToOne(v ^ thirtyHexTwos), 60 - 2 * i);
671
672 // Test comparisons
673 EXPECT_EQ(v == thirtyHexOnes, i == 0);
674 EXPECT_EQ(v == thirtyHexTwos, i == 30);
675 EXPECT_EQ(v > thirtyHexOnes, i > 0);
676 EXPECT_EQ(v > thirtyHexTwos, false);
677 EXPECT_EQ(v >= thirtyHexOnes, true);
678 EXPECT_EQ(v >= thirtyHexTwos, i == 30);
679 EXPECT_EQ(v < thirtyHexOnes, false);
680 EXPECT_EQ(v < thirtyHexTwos, i < 30);
681 EXPECT_EQ(v <= thirtyHexOnes, i == 0);
682 EXPECT_EQ(v <= thirtyHexTwos, true);
683
684 // Update v, clearing upper-most byte
685 v = ((v << 12) >> 8) | 0x2;
686 }
687
688 for (int i = 0; i < 128; ++i) {
689 // Test shifts
690 Unsigned128 sl = thirtyHexOnes << i;
691 Unsigned128 sr = thirtyHexOnes >> i;
692 EXPECT_EQ(BitsSetToOne(sl), std::min(30, 32 - i / 4));
693 EXPECT_EQ(BitsSetToOne(sr), std::max(0, 30 - (i + 3) / 4));
694 EXPECT_EQ(BitsSetToOne(sl & sr), i % 2 ? 0 : std::max(0, 30 - i / 2));
695 }
696
697 // Test 64x64->128 multiply
698 Unsigned128 product =
699 Multiply64to128(0x1111111111111111U, 0x2222222222222222U);
700 EXPECT_EQ(Lower64of128(product), 2295594818061633090U);
701 EXPECT_EQ(Upper64of128(product), 163971058432973792U);
702 }
703
TEST(MathTest,Coding128)704 TEST(MathTest, Coding128) {
705 const char *in = "_1234567890123456";
706 // Note: in + 1 is likely unaligned
707 Unsigned128 decoded = DecodeFixed128(in + 1);
708 EXPECT_EQ(Lower64of128(decoded), 0x3837363534333231U);
709 EXPECT_EQ(Upper64of128(decoded), 0x3635343332313039U);
710 char out[18];
711 out[0] = '_';
712 EncodeFixed128(out + 1, decoded);
713 out[17] = '\0';
714 EXPECT_EQ(std::string(in), std::string(out));
715 }
716
TEST(MathTest,CodingGeneric)717 TEST(MathTest, CodingGeneric) {
718 const char *in = "_1234567890123456";
719 // Decode
720 // Note: in + 1 is likely unaligned
721 Unsigned128 decoded128 = DecodeFixedGeneric<Unsigned128>(in + 1);
722 EXPECT_EQ(Lower64of128(decoded128), 0x3837363534333231U);
723 EXPECT_EQ(Upper64of128(decoded128), 0x3635343332313039U);
724
725 uint64_t decoded64 = DecodeFixedGeneric<uint64_t>(in + 1);
726 EXPECT_EQ(decoded64, 0x3837363534333231U);
727
728 uint32_t decoded32 = DecodeFixedGeneric<uint32_t>(in + 1);
729 EXPECT_EQ(decoded32, 0x34333231U);
730
731 uint16_t decoded16 = DecodeFixedGeneric<uint16_t>(in + 1);
732 EXPECT_EQ(decoded16, 0x3231U);
733
734 // Encode
735 char out[18];
736 out[0] = '_';
737 memset(out + 1, '\0', 17);
738 EncodeFixedGeneric(out + 1, decoded128);
739 EXPECT_EQ(std::string(in), std::string(out));
740
741 memset(out + 1, '\0', 9);
742 EncodeFixedGeneric(out + 1, decoded64);
743 EXPECT_EQ(std::string("_12345678"), std::string(out));
744
745 memset(out + 1, '\0', 5);
746 EncodeFixedGeneric(out + 1, decoded32);
747 EXPECT_EQ(std::string("_1234"), std::string(out));
748
749 memset(out + 1, '\0', 3);
750 EncodeFixedGeneric(out + 1, decoded16);
751 EXPECT_EQ(std::string("_12"), std::string(out));
752 }
753
main(int argc,char ** argv)754 int main(int argc, char** argv) {
755 fprintf(stderr, "NPHash64 id: %x\n",
756 static_cast<int>(ROCKSDB_NAMESPACE::GetSliceNPHash64("RocksDB")));
757 ::testing::InitGoogleTest(&argc, argv);
758
759 return RUN_ALL_TESTS();
760 }
761