1 /* VTreeFS - sdbm.c - sdbm hash function */
2
3 /*
4 * sdbm - ndbm work-alike hashed database library
5 * based on Per-Aake Larson's Dynamic Hashing algorithms. BIT 18 (1978).
6 * author: oz@nexus.yorku.ca
7 * status: public domain. keep it that way.
8 *
9 * hashing routine
10 */
11
12 #include "inc.h"
13
14 /*
15 * polynomial conversion ignoring overflows
16 * [this seems to work remarkably well, in fact better
17 * than the ndbm hash function. Replace at your own risk]
18 * use: 65599 nice.
19 * 65587 even better.
20 */
21 long
sdbm_hash(const char * str,int len)22 sdbm_hash(const char *str, int len)
23 {
24 unsigned long n = 0;
25
26 while (len--)
27 n = *str++ + (n << 6) + (n << 16) - n;
28
29 return n;
30 }
31