RubHub Auth Store

This crate provides an interface for storing and retrieving sensitive data, mainly used for authentication.

So for example to look up the user for a given session you can call AuthStore::get_user_by_session. To persist any changes you can call functions like User::save.

All of this is implemented via an append-only log that is stored in data/auth.ndjson by default. On startup we read this file and parse it line by line updating an in-memory representation (currently a DashMap), so if a user gets defined multiple times in the file later entries overwrite what came before.

This way we can simplify things quite a bit, since whenever something changed we only need to append a single line to the file. To delete an entry we have variants that specify which user/session to delete.

One limitation is that this means that every single user/session token needs to be in memory at all times, since a single User record is just a couple hundred bytes though this shouldn't be much of an issue in practice. This however means that we can look up the user for a given session without doing any filesystem operations.