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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 | ||
23 | /* The most generic version, hashes an arbitrary sequence | |
24 | * of bytes. No alignment or length assumptions are made about | |
25 | * the input key. | |
26 | */ | |
27 | u_int32_t jhash(void *key, u_int32_t length, u_int32_t initval); | |
28 | ||
29 | /* A special optimized version that handles 1 or more of u_int32_ts. | |
30 | * The length parameter here is the number of u_int32_ts in the key. | |
31 | */ | |
32 | u_int32_t jhash2(u_int32_t *k, u_int32_t length, u_int32_t initval); | |
33 | ||
34 | /* A special ultra-optimized versions that knows they are hashing exactly | |
35 | * 3, 2 or 1 word(s). | |
36 | * | |
37 | * NOTE: In partilar the "c += length; __jhash_mix(a,b,c);" normally | |
38 | * done at the end is not done here. | |
39 | */ | |
40 | u_int32_t jhash_3words(u_int32_t a, u_int32_t b, u_int32_t c, u_int32_t initval); | |
41 | u_int32_t jhash_2words(u_int32_t a, u_int32_t b, u_int32_t initval); | |
42 | u_int32_t jhash_1word(u_int32_t a, u_int32_t initval); | |
43 | ||
44 | #endif /* _QUAGGA_JHASH_H */ |