[Feature suggestion] Prefetch when expired

[alpominth]

In Unbound, prefetching is different from Blocky, but it's useful:

       prefetch: <yes or no>
              If yes, message cache elements are prefetched before they expire
              to keep the cache up to date.  Default is  no.   Turning  it  on
              gives about 10 percent more traffic and load on the machine, but
              popular items do not expire from the cache.

/\ https://nlnetlabs.nl/documentation/unbound/unbound.conf/

An option in Block to prefetch elements in the cache when they expire would be a good idea.

In a large cache, combined with Blocky's prefetch approach would help to keep hostnames always updated.

[kwitsch]

This feature is already implemented.
https://0xerr0r.github.io/blocky/configuration/#caching

[alpominth]

@kwitsch

Thanks, I got.

If you or another contributor could implement #833 , together with cache prefetching would make Blocky overkill.

I'm already using Blocky in production! =)