blob: 51fa849cf828c57cc42b2fcf173f670c62f6c935 (
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
86
87
88
89
|
/* Chrysalide - Outil d'analyse de fichiers binaires
* fnv1a.c - implémentaton du calcul rapide d'empreintes de chaînes
*
* Copyright (C) 2012-2017 Cyrille Bagard
*
* This file is part of Chrysalide.
*
* Chrysalide 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.
*
* Chrysalide 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 Foobar. If not, see <http://www.gnu.org/licenses/>.
*/
#include "fnv1a.h"
/* Constante d'initialisation */
#define FNV1A_64_INIT 0xcbf29ce484222325ull
/* Coefficient magique ! */
#define FNV_64_PRIME 0x100000001b3ull
/******************************************************************************
* *
* Paramètres : a = première empreinte à manipuler. *
* b = seconde empreinte à manipuler. *
* *
* Description : Détermine si deux empreintes FNV1a sont indentiques ou non. *
* *
* Retour : Bilan de la comparaison : -1, 0 ou 1. *
* *
* Remarques : - *
* *
******************************************************************************/
int cmp_fnv_64a(fnv64_t a, fnv64_t b)
{
int result; /* Bilan à retourner */
if (a < b) result = -1;
else if (a == b) result = 0;
else result = 1;
return result;
}
/******************************************************************************
* *
* Paramètres : str = chaîne de caractères à traiter. *
* *
* Description : Détermine l'empreinte FNV1a d'une chaîne de caractères. *
* *
* Retour : Valeur calculée. *
* *
* Remarques : - *
* *
******************************************************************************/
fnv64_t fnv_64a_hash(const char *str)
{
fnv64_t result; /* Valeur à retourner */
unsigned char *iter; /* Boucle de parcours */
result = FNV1A_64_INIT;
for (iter = (unsigned char *)str; *iter; iter++)
{
result ^= (fnv64_t)*iter;
result *= FNV_64_PRIME;
}
return result;
}
|
