I want to use `MutableStateFlow` as a cache for a ...

# coroutines

[benkuly]

I want to use MutableStateFlow as a cache for a database (sqldelight). It means, that e. g. I have fun getKeysForUser(userId:String):MutableStateFlow<Keys?>, which first looks in the cache (just a MutableMap) if it contains a matching MutableStateFlow and if not, creates one with an initial value from the database. It then also launches a coroutine to collect from the MutableStateFlow and write to the database on changes. If there are no subscribers anymore (except from the db-collect), I want to remove it from the cache. What is the best way to do it and does this whole idea work?

[CLOVIS]

I implemented more or less exactly that: https://gitlab.com/braindot/clovis/-/blob/master/core.primitives/src/commonMain/kotlin/clovis/core/cache/MemoryCache.kt

To read the code, Ref is a class that stores both an ID and has a suspend method to perform the request

[CLOVIS]

The basic principles are unit tested and it seems to work fine, but there might be issues lurking