Hi.
I wrote a small hashlib for C. Because I'm new to hashes I looked at pythons implementation and
reused *some* of the code... or more the mathematical "hash-function", not really the code.
In particular I looked at pythons hash and lookup functions, so I came up with this (see the code
underneath).
So, can this code be considered as derived and do I have to put my code under the GPL? I'd like to
publish it under something less restrictive, like a BSD style license. But if GPL is the only way,
then GPL it is. :)
-panzi
#define PERTURB_SHIFT 5
static ENTRY_T * lookup(CONTAINER_T * table, hash_const_str_t key,
int (*loop_cond)(ENTRY_T * ptr, hash_const_str_t key)) {
register ENTRY_T * entries = table->entries;
register hash_size_t size = table->size;
register hash_size_t pos = hash(key) % size;
register hash_size_t perturb = pos;
register ENTRY_T * ptr = entries + pos;
while(loop_cond(ptr,key)) {
pos = ((pos << 2) + pos + perturb + 1) % size;
perturb >>= PERTURB_SHIFT;
ptr = entries + pos;
#ifdef HASH_COUNT_COLLISIONS
++ table->collisions;
#endif
}
return ptr;
}
hash_t hash(register hash_const_str_t str) {
/* python 2.5's hash function: */
register hash_size_t len;
register hash_t h;
assert(str);
len = strlen(str);
h = *str << 7;
while (*str)
h = (1000003 * h) ^ *str ++;
h ^= len;
return h;
}
