Line data Source code
1 : /*
2 : * xxHash - Extremely Fast Hash algorithm
3 : * Copyright (C) 2012-2016, Yann Collet.
4 : *
5 : * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
6 : *
7 : * Redistribution and use in source and binary forms, with or without
8 : * modification, are permitted provided that the following conditions are
9 : * met:
10 : *
11 : * * Redistributions of source code must retain the above copyright
12 : * notice, this list of conditions and the following disclaimer.
13 : * * Redistributions in binary form must reproduce the above
14 : * copyright notice, this list of conditions and the following disclaimer
15 : * in the documentation and/or other materials provided with the
16 : * distribution.
17 : *
18 : * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 : * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 : * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 : * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 : * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 : * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 : * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 : * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 : * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 : * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 : * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 : *
30 : * This program is free software; you can redistribute it and/or modify it under
31 : * the terms of the GNU General Public License version 2 as published by the
32 : * Free Software Foundation. This program is dual-licensed; you may select
33 : * either version 2 of the GNU General Public License ("GPL") or BSD license
34 : * ("BSD").
35 : *
36 : * You can contact the author at:
37 : * - xxHash homepage: https://cyan4973.github.io/xxHash/
38 : * - xxHash source repository: https://github.com/Cyan4973/xxHash
39 : */
40 :
41 : /*
42 : * Notice extracted from xxHash homepage:
43 : *
44 : * xxHash is an extremely fast Hash algorithm, running at RAM speed limits.
45 : * It also successfully passes all tests from the SMHasher suite.
46 : *
47 : * Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2
48 : * Duo @3GHz)
49 : *
50 : * Name Speed Q.Score Author
51 : * xxHash 5.4 GB/s 10
52 : * CrapWow 3.2 GB/s 2 Andrew
53 : * MumurHash 3a 2.7 GB/s 10 Austin Appleby
54 : * SpookyHash 2.0 GB/s 10 Bob Jenkins
55 : * SBox 1.4 GB/s 9 Bret Mulvey
56 : * Lookup3 1.2 GB/s 9 Bob Jenkins
57 : * SuperFastHash 1.2 GB/s 1 Paul Hsieh
58 : * CityHash64 1.05 GB/s 10 Pike & Alakuijala
59 : * FNV 0.55 GB/s 5 Fowler, Noll, Vo
60 : * CRC32 0.43 GB/s 9
61 : * MD5-32 0.33 GB/s 10 Ronald L. Rivest
62 : * SHA1-32 0.28 GB/s 10
63 : *
64 : * Q.Score is a measure of quality of the hash function.
65 : * It depends on successfully passing SMHasher test set.
66 : * 10 is a perfect score.
67 : *
68 : * A 64-bits version, named xxh64 offers much better speed,
69 : * but for 64-bits applications only.
70 : * Name Speed on 64 bits Speed on 32 bits
71 : * xxh64 13.8 GB/s 1.9 GB/s
72 : * xxh32 6.8 GB/s 6.0 GB/s
73 : */
74 :
75 : #ifndef XXHASH_H
76 : #define XXHASH_H
77 :
78 : #include <linux/types.h>
79 :
80 : /*-****************************
81 : * Simple Hash Functions
82 : *****************************/
83 :
84 : /**
85 : * xxh32() - calculate the 32-bit hash of the input with a given seed.
86 : *
87 : * @input: The data to hash.
88 : * @length: The length of the data to hash.
89 : * @seed: The seed can be used to alter the result predictably.
90 : *
91 : * Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
92 : *
93 : * Return: The 32-bit hash of the data.
94 : */
95 : uint32_t xxh32(const void *input, size_t length, uint32_t seed);
96 :
97 : /**
98 : * xxh64() - calculate the 64-bit hash of the input with a given seed.
99 : *
100 : * @input: The data to hash.
101 : * @length: The length of the data to hash.
102 : * @seed: The seed can be used to alter the result predictably.
103 : *
104 : * This function runs 2x faster on 64-bit systems, but slower on 32-bit systems.
105 : *
106 : * Return: The 64-bit hash of the data.
107 : */
108 : uint64_t xxh64(const void *input, size_t length, uint64_t seed);
109 :
110 : /**
111 : * xxhash() - calculate wordsize hash of the input with a given seed
112 : * @input: The data to hash.
113 : * @length: The length of the data to hash.
114 : * @seed: The seed can be used to alter the result predictably.
115 : *
116 : * If the hash does not need to be comparable between machines with
117 : * different word sizes, this function will call whichever of xxh32()
118 : * or xxh64() is faster.
119 : *
120 : * Return: wordsize hash of the data.
121 : */
122 :
123 1 : static inline unsigned long xxhash(const void *input, size_t length,
124 : uint64_t seed)
125 : {
126 : #if BITS_PER_LONG == 64
127 1 : return xxh64(input, length, seed);
128 : #else
129 : return xxh32(input, length, seed);
130 : #endif
131 : }
132 :
133 : /*-****************************
134 : * Streaming Hash Functions
135 : *****************************/
136 :
137 : /*
138 : * These definitions are only meant to allow allocation of XXH state
139 : * statically, on stack, or in a struct for example.
140 : * Do not use members directly.
141 : */
142 :
143 : /**
144 : * struct xxh32_state - private xxh32 state, do not use members directly
145 : */
146 : struct xxh32_state {
147 : uint32_t total_len_32;
148 : uint32_t large_len;
149 : uint32_t v1;
150 : uint32_t v2;
151 : uint32_t v3;
152 : uint32_t v4;
153 : uint32_t mem32[4];
154 : uint32_t memsize;
155 : };
156 :
157 : /**
158 : * struct xxh32_state - private xxh64 state, do not use members directly
159 : */
160 : struct xxh64_state {
161 : uint64_t total_len;
162 : uint64_t v1;
163 : uint64_t v2;
164 : uint64_t v3;
165 : uint64_t v4;
166 : uint64_t mem64[4];
167 : uint32_t memsize;
168 : };
169 :
170 : /**
171 : * xxh32_reset() - reset the xxh32 state to start a new hashing operation
172 : *
173 : * @state: The xxh32 state to reset.
174 : * @seed: Initialize the hash state with this seed.
175 : *
176 : * Call this function on any xxh32_state to prepare for a new hashing operation.
177 : */
178 : void xxh32_reset(struct xxh32_state *state, uint32_t seed);
179 :
180 : /**
181 : * xxh32_update() - hash the data given and update the xxh32 state
182 : *
183 : * @state: The xxh32 state to update.
184 : * @input: The data to hash.
185 : * @length: The length of the data to hash.
186 : *
187 : * After calling xxh32_reset() call xxh32_update() as many times as necessary.
188 : *
189 : * Return: Zero on success, otherwise an error code.
190 : */
191 : int xxh32_update(struct xxh32_state *state, const void *input, size_t length);
192 :
193 : /**
194 : * xxh32_digest() - produce the current xxh32 hash
195 : *
196 : * @state: Produce the current xxh32 hash of this state.
197 : *
198 : * A hash value can be produced at any time. It is still possible to continue
199 : * inserting input into the hash state after a call to xxh32_digest(), and
200 : * generate new hashes later on, by calling xxh32_digest() again.
201 : *
202 : * Return: The xxh32 hash stored in the state.
203 : */
204 : uint32_t xxh32_digest(const struct xxh32_state *state);
205 :
206 : /**
207 : * xxh64_reset() - reset the xxh64 state to start a new hashing operation
208 : *
209 : * @state: The xxh64 state to reset.
210 : * @seed: Initialize the hash state with this seed.
211 : */
212 : void xxh64_reset(struct xxh64_state *state, uint64_t seed);
213 :
214 : /**
215 : * xxh64_update() - hash the data given and update the xxh64 state
216 : * @state: The xxh64 state to update.
217 : * @input: The data to hash.
218 : * @length: The length of the data to hash.
219 : *
220 : * After calling xxh64_reset() call xxh64_update() as many times as necessary.
221 : *
222 : * Return: Zero on success, otherwise an error code.
223 : */
224 : int xxh64_update(struct xxh64_state *state, const void *input, size_t length);
225 :
226 : /**
227 : * xxh64_digest() - produce the current xxh64 hash
228 : *
229 : * @state: Produce the current xxh64 hash of this state.
230 : *
231 : * A hash value can be produced at any time. It is still possible to continue
232 : * inserting input into the hash state after a call to xxh64_digest(), and
233 : * generate new hashes later on, by calling xxh64_digest() again.
234 : *
235 : * Return: The xxh64 hash stored in the state.
236 : */
237 : uint64_t xxh64_digest(const struct xxh64_state *state);
238 :
239 : /*-**************************
240 : * Utils
241 : ***************************/
242 :
243 : /**
244 : * xxh32_copy_state() - copy the source state into the destination state
245 : *
246 : * @src: The source xxh32 state.
247 : * @dst: The destination xxh32 state.
248 : */
249 : void xxh32_copy_state(struct xxh32_state *dst, const struct xxh32_state *src);
250 :
251 : /**
252 : * xxh64_copy_state() - copy the source state into the destination state
253 : *
254 : * @src: The source xxh64 state.
255 : * @dst: The destination xxh64 state.
256 : */
257 : void xxh64_copy_state(struct xxh64_state *dst, const struct xxh64_state *src);
258 :
259 : #endif /* XXHASH_H */
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