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mxxhash.h
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1 /*
2  xxHash - Extremely Fast Hash algorithm
3  Header File
4  Copyright (C) 2012-2015, Yann Collet.
5 
6  BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
7 
8  Redistribution and use in source and binary forms, with or without
9  modification, are permitted provided that the following conditions are
10  met:
11 
12  * Redistributions of source code must retain the above copyright
13  notice, this list of conditions and the following disclaimer.
14  * Redistributions in binary form must reproduce the above
15  copyright notice, this list of conditions and the following disclaimer
16  in the documentation and/or other materials provided with the
17  distribution.
18 
19  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31  You can contact the author at :
32  - xxHash source repository : https://github.com/Cyan4973/xxHash
33 */
34 
35 /* Notice extracted from xxHash homepage :
36 
37 xxHash is an extremely fast Hash algorithm, running at RAM speed limits.
38 It also successfully passes all tests from the SMHasher suite.
39 
40 Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz)
41 
42 Name Speed Q.Score Author
43 xxHash 5.4 GB/s 10
44 CrapWow 3.2 GB/s 2 Andrew
45 MumurHash 3a 2.7 GB/s 10 Austin Appleby
46 SpookyHash 2.0 GB/s 10 Bob Jenkins
47 SBox 1.4 GB/s 9 Bret Mulvey
48 Lookup3 1.2 GB/s 9 Bob Jenkins
49 SuperFastHash 1.2 GB/s 1 Paul Hsieh
50 CityHash64 1.05 GB/s 10 Pike & Alakuijala
51 FNV 0.55 GB/s 5 Fowler, Noll, Vo
52 CRC32 0.43 GB/s 9
53 MD5-32 0.33 GB/s 10 Ronald L. Rivest
54 SHA1-32 0.28 GB/s 10
55 
56 Q.Score is a measure of quality of the hash function.
57 It depends on successfully passing SMHasher test set.
58 10 is a perfect score.
59 
60 A 64-bits version, named XXH64, is available since r35.
61 It offers much better speed, but for 64-bits applications only.
62 Name Speed on 64 bits Speed on 32 bits
63 XXH64 13.8 GB/s 1.9 GB/s
64 XXH32 6.8 GB/s 6.0 GB/s
65 */
66 
67 #pragma once
68 
69 //#if defined (__cplusplus)
70 //extern "C" {
71 //#endif
72 
73 
74 /*****************************
75 * Definitions
76 *****************************/
77 #include <stddef.h> /* size_t */
78 typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode;
79 
80 
81 /*****************************
82 * Namespace Emulation
83 *****************************/
84 /* Motivations :
85 
86 If you need to include xxHash into your library,
87 but wish to avoid xxHash symbols to be present on your library interface
88 in an effort to avoid potential name collision if another library also includes xxHash,
89 
90 you can use XXH_NAMESPACE, which will automatically prefix any symbol from xxHash
91 with the value of XXH_NAMESPACE (so avoid to keep it NULL, and avoid numeric values).
92 
93 Note that no change is required within the calling program :
94 it can still call xxHash functions using their regular name.
95 They will be automatically translated by this header.
96 */
97 
98 #define XXH_NAMESPACE mlz4_
99 
100 #ifdef XXH_NAMESPACE
101 # define XXH_CAT(A,B) A##B
102 # define XXH_NAME2(A,B) XXH_CAT(A,B)
103 # define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
104 # define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
105 # define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
106 # define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
107 # define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
108 # define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
109 # define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
110 # define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
111 # define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
112 # define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
113 # define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
114 # define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
115 #endif
116 
117 
118 /*****************************
119 * Simple Hash Functions
120 *****************************/
121 
122 unsigned int XXH32 (const void* input, size_t length, unsigned seed);
123 unsigned long long XXH64 (const void* input, size_t length, unsigned long long seed);
124 
125 /*
126 XXH32() :
127  Calculate the 32-bits hash of sequence "length" bytes stored at memory address "input".
128  The memory between input & input+length must be valid (allocated and read-accessible).
129  "seed" can be used to alter the result predictably.
130  This function successfully passes all SMHasher tests.
131  Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
132 XXH64() :
133  Calculate the 64-bits hash of sequence of length "len" stored at memory address "input".
134  Faster on 64-bits systems. Slower on 32-bits systems.
135 */
136 
137 
138 
139 /*****************************
140 * Advanced Hash Functions
141 *****************************/
142 typedef struct { long long ll[ 6]; } XXH32_state_t;
143 typedef struct { long long ll[11]; } XXH64_state_t;
144 
145 /*
146 These structures allow static allocation of XXH states.
147 States must then be initialized using XXHnn_reset() before first use.
148 
149 If you prefer dynamic allocation, please refer to functions below.
150 */
151 
154 
157 
158 /*
159 These functions create and release memory for XXH state.
160 States must then be initialized using XXHnn_reset() before first use.
161 */
162 
163 
164 XXH_errorcode XXH32_reset (XXH32_state_t* statePtr, unsigned seed);
165 XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length);
166 unsigned int XXH32_digest (const XXH32_state_t* statePtr);
167 
168 XXH_errorcode XXH64_reset (XXH64_state_t* statePtr, unsigned long long seed);
169 XXH_errorcode XXH64_update (XXH64_state_t* statePtr, const void* input, size_t length);
170 unsigned long long XXH64_digest (const XXH64_state_t* statePtr);
171 
172 /*
173 These functions calculate the xxHash of an input provided in multiple smaller packets,
174 as opposed to an input provided as a single block.
175 
176 XXH state space must first be allocated, using either static or dynamic method provided above.
177 
178 Start a new hash by initializing state with a seed, using XXHnn_reset().
179 
180 Then, feed the hash state by calling XXHnn_update() as many times as necessary.
181 Obviously, input must be valid, meaning allocated and read accessible.
182 The function returns an error code, with 0 meaning OK, and any other value meaning there is an error.
183 
184 Finally, you can produce a hash anytime, by using XXHnn_digest().
185 This function returns the final nn-bits hash.
186 You can nonetheless continue feeding the hash state with more input,
187 and therefore get some new hashes, by calling again XXHnn_digest().
188 
189 When you are done, don't forget to free XXH state space, using typically XXHnn_freeState().
190 */
191 
192 
193 //#if defined (__cplusplus)
194 //}
195 //#endif
XXH_errorcode
Definition: mxxhash.h:78
@ XXH_ERROR
Definition: mxxhash.h:78
@ XXH_OK
Definition: mxxhash.h:78
#define XXH32_update
Definition: mxxhash.h:111
#define XXH64_freeState
Definition: mxxhash.h:108
#define XXH32_reset
Definition: mxxhash.h:109
#define XXH64_digest
Definition: mxxhash.h:114
#define XXH64_createState
Definition: mxxhash.h:106
#define XXH32_freeState
Definition: mxxhash.h:107
#define XXH32
Definition: mxxhash.h:103
#define XXH64_reset
Definition: mxxhash.h:110
#define XXH32_digest
Definition: mxxhash.h:113
#define XXH64_update
Definition: mxxhash.h:112
#define XXH32_createState
Definition: mxxhash.h:105
#define XXH64
Definition: mxxhash.h:104