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
11 typedef uint32_t Fnv32_t;
12 typedef uint64_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
20 static __inline Fnv32_t
fnv_32_buf(const void * buf,size_t len,Fnv32_t hval)21 fnv_32_buf(const void *buf, size_t len, Fnv32_t hval)
22 {
23 const uint8_t *s = (const uint8_t *)buf;
24
25 while (len-- != 0) {
26 hval *= FNV_32_PRIME;
27 hval ^= *s++;
28 }
29 return (hval);
30 }
31
32 static __inline Fnv32_t
fnv_32_str(const char * str,Fnv32_t hval)33 fnv_32_str(const char *str, Fnv32_t hval)
34 {
35 const uint8_t *s = (const uint8_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
45 static __inline Fnv64_t
fnv_64_buf(const void * buf,size_t len,Fnv64_t hval)46 fnv_64_buf(const void *buf, size_t len, Fnv64_t hval)
47 {
48 const uint8_t *s = (const uint8_t *)buf;
49
50 while (len-- != 0) {
51 hval *= FNV_64_PRIME;
52 hval ^= *s++;
53 }
54 return (hval);
55 }
56
57 static __inline Fnv64_t
fnv_64_str(const char * str,Fnv64_t hval)58 fnv_64_str(const char *str, Fnv64_t hval)
59 {
60 const uint8_t *s = (const uint8_t *)str;
61 uint32_t c;
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_ */
70