blob: 2dbed339113ff2206e98790863d78373cc182f48 [file] [log] [blame]
/*-
* Fowler / Noll / Vo Hash (FNV Hash)
* http://www.isthe.com/chongo/tech/comp/fnv/
*
* This is an implementation of the algorithms posted above.
* This file is placed in the public domain by Peter Wemm.
*
* $FreeBSD$
*/
typedef u_int32_t Fnv32_t;
typedef u_int64_t Fnv64_t;
#define FNV1_32_INIT ((Fnv32_t) 33554467UL)
#define FNV1_64_INIT ((Fnv64_t) 0xcbf29ce484222325ULL)
#define FNV_32_PRIME ((Fnv32_t) 0x01000193UL)
#define FNV_64_PRIME ((Fnv64_t) 0x100000001b3ULL)
static __inline Fnv32_t
fnv_32_buf(const void *buf, size_t len, Fnv32_t hval)
{
const u_int8_t *s = (const u_int8_t *)buf;
while (len-- != 0) {
hval *= FNV_32_PRIME;
hval ^= *s++;
}
return hval;
}
static __inline Fnv32_t
fnv_32_str(const char *str, Fnv32_t hval)
{
const u_int8_t *s = (const u_int8_t *)str;
Fnv32_t c;
while ((c = *s++) != 0) {
hval *= FNV_32_PRIME;
hval ^= c;
}
return hval;
}
static __inline Fnv64_t
fnv_64_buf(const void *buf, size_t len, Fnv64_t hval)
{
const u_int8_t *s = (const u_int8_t *)buf;
while (len-- != 0) {
hval *= FNV_64_PRIME;
hval ^= *s++;
}
return hval;
}
static __inline Fnv64_t
fnv_64_str(const char *str, Fnv64_t hval)
{
const u_int8_t *s = (const u_int8_t *)str;
u_register_t c; /* 32 bit on i386, 64 bit on alpha,ia64 */
while ((c = *s++) != 0) {
hval *= FNV_64_PRIME;
hval ^= c;
}
return hval;
}