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_ */
72