This hash function takes 15 rounds of fnv164, and adds it to the hashmap. It then adds the hashmap to the cash, and the cashmap to itself, to increase memory usage to several megabytes. Finally, it compresses the hash down to a 64 bit fnv164 string. All of this takes 70+ms, which is longer than the 1-2ms of the original 1000x fnv164 hash.