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 | |