xxhash.h
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1 /*
2  xxHash - Fast Hash algorithm
3  Header File
4  Copyright (C) 2012-2014, Yann Collet.
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  You can contact the author at :
31  - xxHash source repository : http://code.google.com/p/xxhash/
32 */
33 
34 /* Notice extracted from xxHash homepage :
35 
36 xxHash is an extremely fast Hash algorithm, running at RAM speed limits.
37 It also successfully passes all tests from the SMHasher suite.
38 
39 Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz)
40 
41 Name Speed Q.Score Author
42 xxHash 5.4 GB/s 10
43 CrapWow 3.2 GB/s 2 Andrew
44 MumurHash 3a 2.7 GB/s 10 Austin Appleby
45 SpookyHash 2.0 GB/s 10 Bob Jenkins
46 SBox 1.4 GB/s 9 Bret Mulvey
47 Lookup3 1.2 GB/s 9 Bob Jenkins
48 SuperFastHash 1.2 GB/s 1 Paul Hsieh
49 CityHash64 1.05 GB/s 10 Pike & Alakuijala
50 FNV 0.55 GB/s 5 Fowler, Noll, Vo
51 CRC32 0.43 GB/s 9
52 MD5-32 0.33 GB/s 10 Ronald L. Rivest
53 SHA1-32 0.28 GB/s 10
54 
55 Q.Score is a measure of quality of the hash function.
56 It depends on successfully passing SMHasher test set.
57 10 is a perfect score.
58 */
59 
60 #pragma once
61 
62 #if defined (__cplusplus)
63 extern "C" {
64 #endif
65 
66 
67 //****************************
68 // Type
69 //****************************
70 typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode;
71 
83 #ifdef XXH_NAMESPACE
84 # define XXH_CAT(A,B) A##B
85 # define XXH_NAME2(A,B) XXH_CAT(A,B)
86 # define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
87 # define XXH32_sizeofState XXH_NAME2(XXH_NAMESPACE, XXH32_sizeofState)
88 # define XXH32_resetState XXH_NAME2(XXH_NAMESPACE, XXH32_resetState)
89 # define XXH32_init XXH_NAME2(XXH_NAMESPACE, XXH32_init)
90 # define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
91 # define XXH32_intermediateDigest XXH_NAME2(XXH_NAMESPACE, XXH32_intermediateDigest)
92 # define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
93 #endif
94 
95 
96 //****************************
97 // Simple Hash Functions
98 //****************************
99 
100 unsigned int XXH32 (const void* input, int len, unsigned int seed);
101 
102 /*
103 XXH32() :
104  Calculate the 32-bits hash of sequence of length "len" stored at memory address "input".
105  The memory between input & input+len must be valid (allocated and read-accessible).
106  "seed" can be used to alter the result predictably.
107  This function successfully passes all SMHasher tests.
108  Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
109  Note that "len" is type "int", which means it is limited to 2^31-1.
110  If your data is larger, use the advanced functions below.
111 */
112 
113 
114 
115 //****************************
116 // Advanced Hash Functions
117 //****************************
118 
119 void* XXH32_init (unsigned int seed);
120 XXH_errorcode XXH32_update (void* state, const void* input, int len);
121 unsigned int XXH32_digest (void* state);
122 
123 /*
124 These functions calculate the xxhash of an input provided in several small packets,
125 as opposed to an input provided as a single block.
126 
127 It must be started with :
128 void* XXH32_init()
129 The function returns a pointer which holds the state of calculation.
130 
131 This pointer must be provided as "void* state" parameter for XXH32_update().
132 XXH32_update() can be called as many times as necessary.
133 The user must provide a valid (allocated) input.
134 The function returns an error code, with 0 meaning OK, and any other value meaning there is an error.
135 Note that "len" is type "int", which means it is limited to 2^31-1.
136 If your data is larger, it is recommended to chunk your data into blocks
137 of size for example 2^30 (1GB) to avoid any "int" overflow issue.
138 
139 Finally, you can end the calculation anytime, by using XXH32_digest().
140 This function returns the final 32-bits hash.
141 You must provide the same "void* state" parameter created by XXH32_init().
142 Memory will be freed by XXH32_digest().
143 */
144 
145 
146 int XXH32_sizeofState();
147 XXH_errorcode XXH32_resetState(void* state, unsigned int seed);
148 
149 #define XXH32_SIZEOFSTATE 48
150 typedef struct { long long ll[(XXH32_SIZEOFSTATE+(sizeof(long long)-1))/sizeof(long long)]; } XXH32_stateSpace_t;
151 /*
152 These functions allow user application to make its own allocation for state.
153 
154 XXH32_sizeofState() is used to know how much space must be allocated for the xxHash 32-bits state.
155 Note that the state must be aligned to access 'long long' fields. Memory must be allocated and referenced by a pointer.
156 This pointer must then be provided as 'state' into XXH32_resetState(), which initializes the state.
157 
158 For static allocation purposes (such as allocation on stack, or freestanding systems without malloc()),
159 use the structure XXH32_stateSpace_t, which will ensure that memory space is large enough and correctly aligned to access 'long long' fields.
160 */
161 
162 
163 unsigned int XXH32_intermediateDigest (void* state);
164 /*
165 This function does the same as XXH32_digest(), generating a 32-bit hash,
166 but preserve memory context.
167 This way, it becomes possible to generate intermediate hashes, and then continue feeding data with XXH32_update().
168 To free memory context, use XXH32_digest(), or free().
169 */
170 
171 
172 
173 //****************************
174 // Deprecated function names
175 //****************************
176 // The following translations are provided to ease code transition
177 // You are encouraged to no longer this function names
178 #define XXH32_feed XXH32_update
179 #define XXH32_result XXH32_digest
180 #define XXH32_getIntermediateResult XXH32_intermediateDigest
181 
182 
183 
184 #if defined (__cplusplus)
185 }
186 #endif
#define XXH32_SIZEOFSTATE
Definition: xxhash.h:149
unsigned int XXH32(const void *input, int len, unsigned int seed)
Definition: xxhash.c:265
unsigned int XXH32_digest(void *state)
Definition: xxhash.c:471
int XXH32_sizeofState()
Definition: xxhash.c:310
XXH_errorcode
Definition: xxhash.h:70
Definition: xxhash.h:70
void * XXH32_init(unsigned int seed)
Definition: xxhash.c:331
XXH_errorcode XXH32_resetState(void *state, unsigned int seed)
Definition: xxhash.c:317
unsigned int XXH32_intermediateDigest(void *state)
Definition: xxhash.c:460
XXH_errorcode XXH32_update(void *state, const void *input, int len)
Definition: xxhash.c:406


roslz4
Author(s): Ben Charrow
autogenerated on Wed Oct 16 2019 03:27:37