blob: f23730bc8c0bb1a0796cce0653c40df9a6a605af (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
/*!
* \file hash-functions.h
*
* \author Lubos Slovak <lubos.slovak@nic.cz>
*
* \brief Various hash functions.
*
* All of the hash functions are downloaded from various sources.
*
* \todo Add references to sources.
*
* \addtogroup hashing
* @{
*/
/* Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _KNOT_HASH_FUNCTIONS_H_
#define _KNOT_HASH_FUNCTIONS_H_
#include <stdint.h>
#include <string.h>
/*
* Fowler / Noll / Vo Hash (FNV Hash)
* http://www.isthe.com/chongo/tech/comp/fnv/
*
* This is an implementation of the algorithms posted above.
* This file is placed in the public domain by Peter Wemm.
*
* $FreeBSD: src/sys/sys/fnv_hash.h,v 1.2.2.1 2001/03/21 10:50:59 peter Exp $
*/
typedef uint32_t Fnv32_t;
#define FNV1_32_INIT ((Fnv32_t) 33554467UL)
#define FNV_32_PRIME ((Fnv32_t) 0x01000193UL)
static __inline Fnv32_t
fnv_32_buf(const void *buf, size_t len, Fnv32_t hval)
{
const uint8_t *s = (const uint8_t *)buf;
while (len-- != 0) {
hval *= FNV_32_PRIME;
hval ^= *s++;
}
return hval;
}
/*!
* \brief Jenkins hash function.
*
* Downloaded from http://burtleburtle.net/bob/hash/evahash.html
*
* \param k Data to hash
* \param length Size of the data in bytes.
* \param initval The previous hash or an arbitrary value.
*
* \return Hash of the data.
*
* \todo Add source.
*/
typedef unsigned long int ub4; /* unsigned 4-byte quantities */
typedef unsigned char ub1; /* unsigned 1-byte quantities */
ub4 jhash(register ub1 *k, register ub4 length, register ub4 initval);
#endif /* _KNOT_HASH_FUNCTIONS_H_ */
/*! @} */
|
