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 */ 27extern u_int32_t jhash(const 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 */ 32extern u_int32_t jhash2(const 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 */ 40extern u_int32_t jhash_3words(u_int32_t a, u_int32_t b, u_int32_t c, u_int32_t initval); 41extern u_int32_t jhash_2words(u_int32_t a, u_int32_t b, u_int32_t initval); 42extern u_int32_t jhash_1word(u_int32_t a, u_int32_t initval); 43 44#endif /* _QUAGGA_JHASH_H */ 45