| paul | b9790b3 | 2004-07-09 14:05:47 +0000 | [diff] [blame^] | 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 */ |