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 
72 
73 
74 //****************************
75 // Simple Hash Functions
76 //****************************
77 
78 unsigned int XXH32 (const void* input, int len, unsigned int seed);
79 
80 /*
81 XXH32() :
82  Calculate the 32-bits hash of sequence of length "len" stored at memory address "input".
83  The memory between input & input+len must be valid (allocated and read-accessible).
84  "seed" can be used to alter the result predictably.
85  This function successfully passes all SMHasher tests.
86  Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
87  Note that "len" is type "int", which means it is limited to 2^31-1.
88  If your data is larger, use the advanced functions below.
89 */
90 
91 
92 
93 //****************************
94 // Advanced Hash Functions
95 //****************************
96 
97 void* XXH32_init (unsigned int seed);
98 XXH_errorcode XXH32_update (void* state, const void* input, int len);
99 unsigned int XXH32_digest (void* state);
100 
101 /*
102 These functions calculate the xxhash of an input provided in several small packets,
103 as opposed to an input provided as a single block.
104 
105 It must be started with :
106 void* XXH32_init()
107 The function returns a pointer which holds the state of calculation.
108 
109 This pointer must be provided as "void* state" parameter for XXH32_update().
110 XXH32_update() can be called as many times as necessary.
111 The user must provide a valid (allocated) input.
112 The function returns an error code, with 0 meaning OK, and any other value meaning there is an error.
113 Note that "len" is type "int", which means it is limited to 2^31-1.
114 If your data is larger, it is recommended to chunk your data into blocks
115 of size for example 2^30 (1GB) to avoid any "int" overflow issue.
116 
117 Finally, you can end the calculation anytime, by using XXH32_digest().
118 This function returns the final 32-bits hash.
119 You must provide the same "void* state" parameter created by XXH32_init().
120 Memory will be freed by XXH32_digest().
121 */
122 
123 
124 int XXH32_sizeofState();
125 XXH_errorcode XXH32_resetState(void* state, unsigned int seed);
126 
127 #define XXH32_SIZEOFSTATE 48
128 typedef struct { long long ll[(XXH32_SIZEOFSTATE+(sizeof(long long)-1))/sizeof(long long)]; } XXH32_stateSpace_t;
129 /*
130 These functions allow user application to make its own allocation for state.
131 
132 XXH32_sizeofState() is used to know how much space must be allocated for the xxHash 32-bits state.
133 Note that the state must be aligned to access 'long long' fields. Memory must be allocated and referenced by a pointer.
134 This pointer must then be provided as 'state' into XXH32_resetState(), which initializes the state.
135 
136 For static allocation purposes (such as allocation on stack, or freestanding systems without malloc()),
137 use the structure XXH32_stateSpace_t, which will ensure that memory space is large enough and correctly aligned to access 'long long' fields.
138 */
139 
140 
141 unsigned int XXH32_intermediateDigest (void* state);
142 /*
143 This function does the same as XXH32_digest(), generating a 32-bit hash,
144 but preserve memory context.
145 This way, it becomes possible to generate intermediate hashes, and then continue feeding data with XXH32_update().
146 To free memory context, use XXH32_digest(), or free().
147 */
148 
149 
150 
151 //****************************
152 // Deprecated function names
153 //****************************
154 // The following translations are provided to ease code transition
155 // You are encouraged to no longer this function names
156 #define XXH32_feed XXH32_update
157 #define XXH32_result XXH32_digest
158 #define XXH32_getIntermediateResult XXH32_intermediateDigest
159 
160 
161 
162 #if defined (__cplusplus)
163 }
164 #endif
#define XXH32_SIZEOFSTATE
Definition: xxhash.h:127
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


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Author(s): Ben Charrow
autogenerated on Mon Nov 2 2020 03:52:18