Disk cache backend

[argaen]

Vote here with 👍 if you are interested on having this

Implementation would be done with https://github.com/Tinche/aiofiles

[N-Coder]

dogpile.cache provides similar (but blocking) caching functionality with a focus on what is called cached_stampede in this library. They also have interchangeable backends and already implemented file-system backed storage and locking in addition to redis and memcached. As aiofiles just wraps the blocking file-system IO calls in run_in_executor, we could simply skip aiofiles, reuse the dogpile.cache DBM-based file backend and wrap it's methods in run_in_executor. Their approach to fs-based locking (in addition to the user customizable mutex creation) also looks promising.

[argaen]

with a focus on what is called cached_stampede in this library

You can protect against cache_stampede with locking provided in aiocache too http://aiocache.readthedocs.io/en/latest/locking.html.

we could simply skip aiofiles, reuse the dogpile.cache DBM-based file backend and wrap it's methods in run_in_executor

If there are enough votes for this feature I'll dig on how to implement it however, without knowing how dogpile is doing it, I don't want to add it as a dependency of this project. If your point was on just reusing the code and wrapping it, yeah could have a look on how to do it.

PS: Obviously contributions are welcome if you want to :)

[paulo-raca]

I've implemented an sqlite backend that should cover the disk-backed storage: #486