Function djb2

pg_documentdb_core/src/collation/collation.c:865–875

* Well known hash function to efficiently calculate hash of a string. While it may have collisions it's unlikely in our case * where the hash function is used to generate hash code for limited number of collation strings. Even if there is collision, * the functionality will not be broken, we will just generate a few more cache entries */

 * the functionality will not be broken, we will just generate a few more cache entries
 */
static unsigned long
djb2(const char *str)
{
	unsigned long hash = 5381;
	int c;
	while ((c = *str++))
	{
		hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
	}
	return hash;
}


/*