1/* $NetBSD: hash.h,v 1.7 2012/07/08 01:24:08 rmind Exp $ */ 2 3/*- 4 * Copyright (c) 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Luke Mewburn. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#ifndef _SYS_HASH_H_ 33#define _SYS_HASH_H_ 34 35#include <sys/types.h> 36 37#ifdef __HAVE_MACHINE_HASH_H 38#include <machine/hash.h> 39#endif 40 41#ifndef __HAVE_HASH32_BUF /* not overridden by MD hash */ 42 43#define HASH32_BUF_INIT 5381 44 45/* 46 * uint32_t 47 * hash32_buf(const void *bf, size_t len, uint32_t hash) 48 * return a 32 bit hash of the binary buffer buf (size len), 49 * seeded with an initial hash value of hash (usually HASH32_BUF_INIT). 50 */ 51static __inline uint32_t 52hash32_buf(const void *bf, size_t len, uint32_t hash) 53{ 54 const uint8_t *s = (const uint8_t *)bf; 55 56 while (len-- != 0) /* "nemesi": k=257, r=r*257 */ 57 hash = hash * 257 + *s++; 58 return (hash * 257); 59} 60#endif /* __HAVE_HASH32_BUF */ 61 62 63#ifndef __HAVE_HASH32_STR /* not overridden by MD hash */ 64 65#define HASH32_STR_INIT 5381 66/* 67 * uint32_t 68 * hash32_str(const void *bf, uint32_t hash) 69 * return a 32 bit hash of NUL terminated ASCII string buf, 70 * seeded with an initial hash value of hash (usually HASH32_STR_INIT). 71 */ 72static __inline uint32_t 73hash32_str(const void *bf, uint32_t hash) 74{ 75 const uint8_t *s = (const uint8_t *)bf; 76 uint8_t c; 77 78 while ((c = *s++) != 0) 79 hash = hash * 33 + c; /* "perl": k=33, r=r+r/32 */ 80 return (hash + (hash >> 5)); 81} 82 83/* 84 * uint32_t 85 * hash32_strn(const void *bf, size_t len, uint32_t hash) 86 * return a 32 bit hash of NUL terminated ASCII string buf up to 87 * a maximum of len bytes, 88 * seeded with an initial hash value of hash (usually HASH32_STR_INIT). 89 */ 90static __inline uint32_t 91hash32_strn(const void *bf, size_t len, uint32_t hash) 92{ 93 const uint8_t *s = (const uint8_t *)bf; 94 uint8_t c; 95 96 while ((c = *s++) != 0 && len-- != 0) 97 hash = hash * 33 + c; /* "perl": k=33, r=r+r/32 */ 98 return (hash + (hash >> 5)); 99} 100#endif /* __HAVE_HASH32_STR */ 101 102__BEGIN_DECLS 103uint32_t murmurhash2(const void *, size_t, uint32_t); 104__END_DECLS 105 106#endif /* !_SYS_HASH_H_ */ 107