Merge from vendor branch AWK:
[dragonfly.git] / sys / sys / fnv_hash.h
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1/*
2 * Fowler / Noll / Vo Hash (FNV Hash)
3 * http://www.isthe.com/chongo/tech/comp/fnv/
4 *
5 * This is an implementation of the algorithms posted above.
6 * This file is placed in the public domain by Peter Wemm.
7 *
8 * $FreeBSD: src/sys/sys/fnv_hash.h,v 1.2.2.1 2001/03/21 10:50:59 peter Exp $
1de703da 9 * $DragonFly: src/sys/sys/fnv_hash.h,v 1.2 2003/06/17 04:28:58 dillon Exp $
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10 */
11
12typedef u_int32_t Fnv32_t;
13typedef u_int64_t Fnv64_t;
14
15#define FNV1_32_INIT ((Fnv32_t) 33554467UL)
16#define FNV1_64_INIT ((Fnv64_t) 0xcbf29ce484222325ULL)
17
18#define FNV_32_PRIME ((Fnv32_t) 0x01000193UL)
19#define FNV_64_PRIME ((Fnv64_t) 0x100000001b3ULL)
20
21static __inline Fnv32_t
22fnv_32_buf(const void *buf, size_t len, Fnv32_t hval)
23{
24 const u_int8_t *s = (const u_int8_t *)buf;
25
26 while (len-- != 0) {
27 hval *= FNV_32_PRIME;
28 hval ^= *s++;
29 }
30 return hval;
31}
32
33static __inline Fnv32_t
34fnv_32_str(const char *str, Fnv32_t hval)
35{
36 const u_int8_t *s = (const u_int8_t *)str;
37 Fnv32_t c;
38
39 while ((c = *s++) != 0) {
40 hval *= FNV_32_PRIME;
41 hval ^= c;
42 }
43 return hval;
44}
45
46static __inline Fnv64_t
47fnv_64_buf(const void *buf, size_t len, Fnv64_t hval)
48{
49 const u_int8_t *s = (const u_int8_t *)buf;
50
51 while (len-- != 0) {
52 hval *= FNV_64_PRIME;
53 hval ^= *s++;
54 }
55 return hval;
56}
57
58static __inline Fnv64_t
59fnv_64_str(const char *str, Fnv64_t hval)
60{
61 const u_int8_t *s = (const u_int8_t *)str;
62 u_register_t c; /* 32 bit on i386, 64 bit on alpha,ia64 */
63
64 while ((c = *s++) != 0) {
65 hval *= FNV_64_PRIME;
66 hval ^= c;
67 }
68 return hval;
69}