v0.21.0

🔂 Conditional Refresh (docs)

FusionCache now fully supports conditional refresh, which is conceptually similar to conditional requests in HTTP.

Basically it is a way to cache and re-use either an ETag, a LastModified date or both, so that it is possible to save resources by not fully getting a remote resource (think: a remote http service response) in case it was not changed since the last time we got it.

Thanks to the community member @aKzenT for the invaluable help with the design discussion.

See here for the original issue.

🦅 Eager Refresh (docs)

It is now possible to tell FusionCache to eagerly start refreshing a value in the cache even before it's expired, all automatically and in the background (without blocking).

For example we can tell FusionCache to cache something for 10 min but eagerly start refreshing it after 90% of that (9 min) in the background, as soon as a GetOrSet<T>(...) call is made after the specified threshold: in this way fresh data will be ready earlier, and without having to wait for the refresh to complete when it would've expired.

Both eager refresh and the usual normal refresh + factory timeouts can be combined, without any problems.

See here for the original issue.

📞 Added EagerRefresh event

A new event has been added, for when eager refresh actually occurs.

📜 Added WithoutLogger() builder method (docs)

With the introduction of the Builder in the v0.20.0 release, something was missing: a way to tell FusionCache to not use a logger, at all: now this is fixed.

Thanks to community member @sherman89 for pointing that out.

See here for the original issue.

⚠ Breaking Change

The type for the factory execution context has changed, from FusionCacheFactoryExecutionContext to FusionCacheFactoryExecutionContext<TValue>: this has been done to support conditional refresh and have access to the stale value already cached, which requires knowing the type upfront.

Most existing code should be fine: the only noticeable difference is that in some situations the C# compiler is, for some reasons, not able to do type inference correctly.

Because of this, in some instances a code like this:

var product = cache.GetOrSet(...);

must be updated to explicitly add the TValue type, like this:

var product = cache.GetOrSet<Product>(...);