Add TTL support?

[bookmoons]

I'm evaluating this for possible use in another project. It seems to be the nicest resolver available, but I need something with an expiring cache that respects TTL.

Would the team consider a PR to support TTL?

[bookmoons]

@ydnar @case Sorry for the ping guys. Wasn't sure if the issue will be seen. I'm inclined to write a patch for this but wanted to ask first if getting it in is a possibility.

[cee-dub]

Thanks for proposing this. Would you tell us a bit about the design you have in mind to add the feature?

[bookmoons]

Thanks for looking at it. I've looked over it a little. The underlying miekg/dns exposes TTL. There's a cache built around this RR struct. It's a benefit this is already structured data, I was looking at other caches but they all store string values.

TTL can be stored in this record when retrieved. Cache reads can then verify liveness and only return if the entry is live. That happens here so an expired entry would trigger a standard query to DNS again.

I'd make it optional so when it's disabled you're not storing TTLs unnecessarily.

[cee-dub]

Will definitely look at a PR. If you can share your use case, that will help us with context, too. Thanks!

[bookmoons]

Wonderful.

[bookmoons]

Made a submission #32 to start this off.