CacheCleared event

[ryanmitchell]

Would you be open to adding (or reviewing a PR for) a CacheCleared event?

We have a use case where we're keeping record of cache entries in a database store, so when the cache is cleared it gets out of sync. It would be useful to be able to listen for that happening and re-sync / re-populate our store at that point.

[henzeb]

do you need the cache entries stored in the database?

[ryanmitchell]

No, its just the keys - its part of a larger caching system where we create dependencies between certain cache keys, so if a linked key is cleared then any dependent keys are also cleared.