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1479465f GJ |
1 | /* |
2 | * libdpkg - Debian packaging suite library routines | |
3 | * strhash.c - FNV string hashing support | |
4 | * | |
5 | * Copyright © 2003 Daniel Silverstone <dsilvers@digital-scurf.org> | |
6 | * | |
7 | * This is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program. If not, see <https://www.gnu.org/licenses/>. | |
19 | */ | |
20 | ||
21 | #include <config.h> | |
22 | #include <compat.h> | |
23 | ||
24 | #include <dpkg/string.h> | |
25 | ||
26 | #define FNV_OFFSET_BASIS 2166136261UL | |
27 | #define FNV_MIXING_PRIME 16777619UL | |
28 | ||
29 | /** | |
30 | * Fowler/Noll/Vo -- FNV-1a simple string hash. | |
31 | * | |
32 | * For more info, @see <http://www.isthe.com/chongo/tech/comp/fnv/index.html>. | |
33 | * | |
34 | * @param str The string to hash. | |
35 | * | |
36 | * @return The hashed value. | |
37 | */ | |
38 | unsigned int | |
39 | str_fnv_hash(const char *str) | |
40 | { | |
41 | register unsigned int h = FNV_OFFSET_BASIS; | |
42 | register unsigned int p = FNV_MIXING_PRIME; | |
43 | ||
44 | while (*str) { | |
45 | h ^= *str++; | |
46 | h *= p; | |
47 | } | |
48 | ||
49 | return h; | |
50 | } |