uint64_t ht_compare_and_set (hashtable_t *ht, const char *key, uint32_t key_len, uint64_t expected_val, uint64_t val);
uint64_t ht_get (hashtable_t *ht, const char *key, uint32_t len);
uint64_t ht_remove (hashtable_t *ht, const char *key, uint32_t len);
uint64_t ht_count (hashtable_t *ht);
uint64_t ht_compare_and_set (hashtable_t *ht, const char *key, uint32_t key_len, uint64_t expected_val, uint64_t val);
uint64_t ht_get (hashtable_t *ht, const char *key, uint32_t len);
uint64_t ht_remove (hashtable_t *ht, const char *key, uint32_t len);
uint64_t ht_count (hashtable_t *ht);