I'm very curious as to how this works in the backend. I realize it uses Bluesky's firehose to get the posts, but I'm more curious on how it's checking whether a post contains any of the available words. Any guesses?
Hey! this is my site - it's not all that complex, i'm just using a sqlite db with two tables - one for stats, the other for all the words that's just word | count | first use | last use | post.
using this, a combo of "covered enough" for the bit and easy to use
also, since i'm tracking every word (technically a better name for this project would be The Bluesky Corpus) all inflected forms are different words, which aligns with my thinking
You can probably fit all words under 10-15MB of memory, but memory optimisations are not even needed for 250k words...
Trie data structures are memory-efficient for storing such dictionaries (2-4x better than hashmaps). Although not as fast as hashmaps for retrieving items. You can hash the top 1k of the most common words and check the rest using a trie.
The most CPU-intensive task here is text tokenizing, but there are a ton of optimized options developed by orgs that work on LLMs.
I very much hope that the backend uses one of the bluesky jetstream endpoints.
When you only subscribe to new posts, it provides a stream of around 20mbit/s last time I checked, while the firehose was ~200mbit/s.
Probably just a big hashtable mapping word -> the number of times it's been seen, and another hashset of all the words it hasn't seen. When a post comes in you hash all the words in it and look them up in the hashtable, increment it, and if the old value was 0 remove it from the hash set.
250k words at a generous 100 bytes per word is only 25MB of memory...
Maybe I'm being naive, but with only ~275k words to check against, this doesn't seem like a particularly hard problem. Ingest post, split by words, check each word via some db, hashmap, etc... and update metadata.