1/*
2   xxHash - Extremely 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
36xxHash is an extremely fast Hash algorithm, running at RAM speed limits.
37It also successfully passes all tests from the SMHasher suite.
38
39Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz)
40
41Name            Speed       Q.Score   Author
42xxHash          5.4 GB/s     10
43CrapWow         3.2 GB/s      2       Andrew
44MumurHash 3a    2.7 GB/s     10       Austin Appleby
45SpookyHash      2.0 GB/s     10       Bob Jenkins
46SBox            1.4 GB/s      9       Bret Mulvey
47Lookup3         1.2 GB/s      9       Bob Jenkins
48SuperFastHash   1.2 GB/s      1       Paul Hsieh
49CityHash64      1.05 GB/s    10       Pike & Alakuijala
50FNV             0.55 GB/s     5       Fowler, Noll, Vo
51CRC32           0.43 GB/s     9
52MD5-32          0.33 GB/s    10       Ronald L. Rivest
53SHA1-32         0.28 GB/s    10
54
55Q.Score is a measure of quality of the hash function.
56It depends on successfully passing SMHasher test set.
5710 is a perfect score.
58*/
59
60#pragma once
61
62#if defined (__cplusplus)
63extern "C" {
64#endif
65
66
67/*****************************
68   Includes
69*****************************/
70#include <stddef.h>   /* size_t */
71
72
73/*****************************
74   Type
75*****************************/
76typedef enum { XXH_OK = 0, XXH_ERROR } XXH_errorcode;
77
78
79
80/*****************************
81   Simple Hash Functions
82*****************************/
83
84unsigned int       XXH32(const void *input, size_t length, unsigned seed);
85unsigned long long XXH64(const void *input, size_t length,
86                         unsigned long long seed);
87
88/*
89XXH32() :
90    Calculate the 32-bits hash of sequence "length" bytes stored at memory address "input".
91    The memory between input & input+length must be valid (allocated and read-accessible).
92    "seed" can be used to alter the result predictably.
93    This function successfully passes all SMHasher tests.
94    Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s
95XXH64() :
96    Calculate the 64-bits hash of sequence of length "len" stored at memory address "input".
97*/
98
99
100
101/*****************************
102   Advanced Hash Functions
103*****************************/
104typedef struct { long long ll[ 6]; } XXH32_state_t;
105typedef struct { long long ll[11]; } XXH64_state_t;
106
107/*
108These structures allow static allocation of XXH states.
109States must then be initialized using XXHnn_reset() before first use.
110
111If you prefer dynamic allocation, please refer to functions below.
112*/
113
114XXH32_state_t *XXH32_createState(void);
115XXH_errorcode  XXH32_freeState(XXH32_state_t *statePtr);
116
117XXH64_state_t *XXH64_createState(void);
118XXH_errorcode  XXH64_freeState(XXH64_state_t *statePtr);
119
120/*
121These functions create and release memory for XXH state.
122States must then be initialized using XXHnn_reset() before first use.
123*/
124
125
126XXH_errorcode XXH32_reset(XXH32_state_t *statePtr, unsigned seed);
127XXH_errorcode XXH32_update(XXH32_state_t *statePtr, const void *input,
128                           size_t length);
129unsigned int  XXH32_digest(const XXH32_state_t *statePtr);
130
131XXH_errorcode      XXH64_reset(XXH64_state_t *statePtr,
132                               unsigned long long seed);
133XXH_errorcode      XXH64_update(XXH64_state_t *statePtr, const void *input,
134                                size_t length);
135unsigned long long XXH64_digest(const XXH64_state_t *statePtr);
136
137/*
138These functions calculate the xxHash of an input provided in multiple smaller packets,
139as opposed to an input provided as a single block.
140
141XXH state space must first be allocated, using either static or dynamic method provided above.
142
143Start a new hash by initializing state with a seed, using XXHnn_reset().
144
145Then, feed the hash state by calling XXHnn_update() as many times as necessary.
146Obviously, input must be valid, meaning allocated and read accessible.
147The function returns an error code, with 0 meaning OK, and any other value meaning there is an error.
148
149Finally, you can produce a hash anytime, by using XXHnn_digest().
150This function returns the final nn-bits hash.
151You can nonetheless continue feeding the hash state with more input,
152and therefore get some new hashes, by calling again XXHnn_digest().
153
154When you are done, don't forget to free XXH state space, using typically XXHnn_freeState().
155*/
156
157
158#if defined (__cplusplus)
159}
160#endif
161