/* * sdbm - ndbm work-alike hashed database library * based on Per-Aake Larson's Dynamic Hashing algorithms. BIT 18 (1978). * author: oz@nexus.yorku.ca * status: public domain. keep it that way. * * hashing routine */ #include "sdbm.h" /* * polynomial conversion ignoring overflows * [this seems to work remarkably well, in fact better * then the ndbm hash function. Replace at your own risk] * use: 65599 nice. * 65587 even better. */ long sdbm_hash(str, len) register char *str; #ifdef VISUAL_CC register int len; #else register size_t len; #endif { register unsigned long n = 0; #ifdef HAVE_DUFF #define HASHC n = *str++ + 65599 * n if (len > 0) { register int loop = (len + 8 - 1) >> 3; switch(len & (8 - 1)) { case 0: do { HASHC; case 7: HASHC; case 6: HASHC; case 5: HASHC; case 4: HASHC; case 3: HASHC; case 2: HASHC; case 1: HASHC; } while (--loop); } } #else while (len--) n = *str++ + 65599 * n; #endif return n; }