danielshaya / reactivejournal Goto Github PK

This currently deletes the whole content of the RxJournal folder, and the folder itself.
IMHO it is too easy to create an RxJournal pointing to an existing folder and then obliterate it with that method. To make this scenario less likely, several steps can be taken:

• better document the RxJournal constructor and clearCache method to indicate it destroys the directory
• limit the clearCache to deleting files inside the directory (and not subdirectories nor the directory itself)
• limit the deletion of files to *.cq4 files, aka only delete binary files from ChronicleQueue
• maybe use the given directory as a "base directory for temporary files" and create a dedicated subdir instead of using it as is. That subdir would then be the only one obliterated.

Continuing the discussion from twitter:

I assume the journal acts as an unbounded buffer that stores items on disk, thus when replaying it can read elements from this disk buffer on demand, supporting backpressure naturally.

The problem I see with the current setup is that unless one consumes the journal directly with a Consumer, it can run into backpressure problems again caused by the replay itself. For example, applying observeOn would trigger a replay to flood the internal buffer of Observable.observeOn thus the backpressure problem is back.