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b9790b34 | 1 | /* jhash.h: Jenkins hash support. |
2 | * | |
3 | * Copyright (C) 1996 Bob Jenkins (bob_jenkins@burtleburtle.net) | |
4 | * | |
5 | * http://burtleburtle.net/bob/hash/ | |
6 | * | |
7 | * These are the credits from Bob's sources: | |
8 | * | |
9 | * lookup2.c, by Bob Jenkins, December 1996, Public Domain. | |
10 | * hash(), hash2(), hash3, and mix() are externally useful functions. | |
11 | * Routines to test the hash are included if SELF_TEST is defined. | |
12 | * You can use this free for any purpose. It has no warranty. | |
13 | * | |
14 | * Copyright (C) 2003 David S. Miller (davem@redhat.com) | |
15 | * | |
16 | * I've modified Bob's hash to be useful in the Linux kernel, and | |
17 | * any bugs present are surely my fault. -DaveM | |
18 | */ | |
19 | ||
20 | #ifndef _QUAGGA_JHASH_H | |
21 | #define _QUAGGA_JHASH_H | |
22 | ||
5e244469 RW |
23 | #ifdef __cplusplus |
24 | extern "C" { | |
25 | #endif | |
26 | ||
b9790b34 | 27 | /* The most generic version, hashes an arbitrary sequence |
28 | * of bytes. No alignment or length assumptions are made about | |
29 | * the input key. | |
30 | */ | |
d7c0a89a | 31 | extern uint32_t jhash(const void *key, uint32_t length, uint32_t initval); |
b9790b34 | 32 | |
d7c0a89a QY |
33 | /* A special optimized version that handles 1 or more of uint32_ts. |
34 | * The length parameter here is the number of uint32_ts in the key. | |
b9790b34 | 35 | */ |
d7c0a89a | 36 | extern uint32_t jhash2(const uint32_t *k, uint32_t length, uint32_t initval); |
b9790b34 | 37 | |
38 | /* A special ultra-optimized versions that knows they are hashing exactly | |
39 | * 3, 2 or 1 word(s). | |
40 | * | |
41 | * NOTE: In partilar the "c += length; __jhash_mix(a,b,c);" normally | |
42 | * done at the end is not done here. | |
43 | */ | |
d7c0a89a QY |
44 | extern uint32_t jhash_3words(uint32_t a, uint32_t b, uint32_t c, |
45 | uint32_t initval); | |
46 | extern uint32_t jhash_2words(uint32_t a, uint32_t b, uint32_t initval); | |
47 | extern uint32_t jhash_1word(uint32_t a, uint32_t initval); | |
b9790b34 | 48 | |
5e244469 RW |
49 | #ifdef __cplusplus |
50 | } | |
51 | #endif | |
52 | ||
b9790b34 | 53 | #endif /* _QUAGGA_JHASH_H */ |