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/*
* 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 "config.h"
#include "EXTERN.h"
#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(const char *str, int len)
{
unsigned long n = 0;
#ifdef DUFF
#define HASHC n = *str++ + 65599 * n
if (len > 0) {
int loop = (len + 8 - 1) >> 3;
switch(len & (8 - 1)) {
case 0: do {
HASHC; /* FALLTHROUGH */ case 7: HASHC; /* FALLTHROUGH */
case 6: HASHC; /* FALLTHROUGH */ case 5: HASHC; /* FALLTHROUGH */
case 4: HASHC; /* FALLTHROUGH */ case 3: HASHC; /* FALLTHROUGH */
case 2: HASHC; /* FALLTHROUGH */ case 1: HASHC;
} while (--loop);
}
}
#else
while (len--)
n = *str++ + 65599 * n;
#endif
return n;
}
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