I noticed they use a Bloom Filter based on ip address to prevent people from voting multiple times. According to the implementation[1] it uses a 256-byte structure and limits the total number of votes on a post to 142 [2] (more than that and the false-positive rate > 0.001). This is stored as a sqlite BLOB on the same row as the comment.

But if you're limiting votes to ~142 anyways, you can just store the exact ip address of every voter (packed in the BLOB at 4 bytes each) and it would only reach up to double the space (~560). But since the overwhelmingly vast majority of comments won't get nearly that many votes, you'd actually be saving space compared to keeping a bloom filter for each comment.

It seems like an overengineered and unnecessary technical complexity.

[1]: https://github.com/posativ/isso/blob/master/isso/utils/__ini...

[2]: https://github.com/posativ/isso/blob/master/isso/db/comments...