1 /* $NetBSD: hash.h,v 1.8 2014/09/05 05:46:15 matt 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 */ 51 static __inline uint32_t 52 hash32_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 */ 72 static __inline uint32_t 73 hash32_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 */ 90 static __inline uint32_t 91 hash32_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 103 uint32_t murmurhash2(const void *, size_t, uint32_t); 104 __END_DECLS 105 106 #endif /* !_SYS_HASH_H_ */ 107
Indexes created Sat Sep 20 22:09:52 GMT 2025