source: rtems-libbsd/freebsd/sys/sys/fnv_hash.h @ 66659ff

4.115-freebsd-12freebsd-9.3
Last change on this file since 66659ff was 66659ff, checked in by Sebastian Huber <sebastian.huber@…>, on Nov 6, 2013 at 3:20:21 PM

Update to FreeBSD 9.2

  • Property mode set to 100644
File size: 1.4 KB
Line 
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 * $FreeBSD$
9 */
10#ifndef _SYS_FNV_HASH_H_
11#define _SYS_FNV_HASH_H_
12
13typedef u_int32_t Fnv32_t;
14typedef u_int64_t Fnv64_t;
15
16#define FNV1_32_INIT ((Fnv32_t) 33554467UL)
17#define FNV1_64_INIT ((Fnv64_t) 0xcbf29ce484222325ULL)
18
19#define FNV_32_PRIME ((Fnv32_t) 0x01000193UL)
20#define FNV_64_PRIME ((Fnv64_t) 0x100000001b3ULL)
21
22static __inline Fnv32_t
23fnv_32_buf(const void *buf, size_t len, Fnv32_t hval)
24{
25        const u_int8_t *s = (const u_int8_t *)buf;
26
27        while (len-- != 0) {
28                hval *= FNV_32_PRIME;
29                hval ^= *s++;
30        }
31        return hval;
32}
33
34static __inline Fnv32_t
35fnv_32_str(const char *str, Fnv32_t hval)
36{
37        const u_int8_t *s = (const u_int8_t *)str;
38        Fnv32_t c;
39
40        while ((c = *s++) != 0) {
41                hval *= FNV_32_PRIME;
42                hval ^= c;
43        }
44        return hval;
45}
46
47static __inline Fnv64_t
48fnv_64_buf(const void *buf, size_t len, Fnv64_t hval)
49{
50        const u_int8_t *s = (const u_int8_t *)buf;
51
52        while (len-- != 0) {
53                hval *= FNV_64_PRIME;
54                hval ^= *s++;
55        }
56        return hval;
57}
58
59static __inline Fnv64_t
60fnv_64_str(const char *str, Fnv64_t hval)
61{
62        const u_int8_t *s = (const u_int8_t *)str;
63        u_register_t c;          /* 32 bit on i386, 64 bit on alpha,ia64 */
64
65        while ((c = *s++) != 0) {
66                hval *= FNV_64_PRIME;
67                hval ^= c;
68        }
69        return hval;
70}
71#endif /* _SYS_FNV_HASH_H_ */
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