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