I have a pretty simple need – simple enough that it’s not a big deal to implement it as a GenServer or similar, but it’s a common enough use case that someone else must have come up with something that fits the bill. The basic need is to have a cache sit in front of a slow MFA call, e.g. a database query. So the cache acts as the source-of-truth, and the MFA call gets applied periodically so it stays “reasonably” up-to-date, and I can hit the database once every few minutes instead of once every few milliseconds and all would be well with the world.

I’m imagining a GenServer that could be started up something like:

GenCache.start_link(%{name: :db_query1, module: MyApp, function: :slow_db_query1, args: [], refresh_interval_ms: 300_000})

which would call MyApp.slow_db_query1/0 every 5 minutes and cache the result in the GenServer state. I could access the cached data via something like:

GenCache.get(:db_query1)

or force it to refresh via

GenCache.refresh(:db_query1)

and a few other functions – hopefully this expresses the idea.

Is anyone aware of such a package that could be pointed at arbitrary existing functions? I’m not sure if this simple use case would even justify a stand-alone package, but I thought the community would have some valuable thoughts on it. Thanks in advance!