blob: 2ffa202278f10f674cbf14999f7fde2d7d79805b (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
#include "theft.h"
/* Fowler/Noll/Vo hash, 64-bit FNV-1a.
* This hashing algorithm is in the public domain.
* For more details, see: http://www.isthe.com/chongo/tech/comp/fnv/. */
static const uint64_t fnv64_prime = 1099511628211L;
static const uint64_t fnv64_offset_basis = 14695981039346656037UL;
/* Init a hasher for incremental hashing. */
void theft_hash_init(struct theft_hasher *h) {
h->accum = fnv64_offset_basis;
}
/* Sink more data into an incremental hash. */
void theft_hash_sink(struct theft_hasher *h, uint8_t *data, size_t bytes) {
if (h == NULL || data == NULL) { return; }
uint64_t a = h->accum;
for (size_t i = 0; i < bytes; i++) {
a = (a ^ data[i]) * fnv64_prime;
}
h->accum = a;
}
/* Finish hashing and get the result. */
theft_hash theft_hash_done(struct theft_hasher *h) {
theft_hash res = h->accum;
theft_hash_init(h); /* reset */
return res;
}
/* Hash a buffer in one pass. (Wraps the above functions.) */
theft_hash theft_hash_onepass(uint8_t *data, size_t bytes) {
struct theft_hasher h;
theft_hash_init(&h);
theft_hash_sink(&h, data, bytes);
return theft_hash_done(&h);
}
|
