feat: prune old, inactive paths

[ramfox]

Description

Prune paths that are not actively being used, never have been holepunched, are not about to be dialed, or old.

Notes and Questions

The logic of gathering all of the relevant information is in the fn prune_ip_paths function, not in the self.prune_ip_paths method on EndpointActorState. Separating these out made it easier to test.

Used AI to help write tests & reduce allocations when working through the paths.

keep_path is where we can play around with what exactly we want to keep, based on the PathState, if we want to get more strict or particular as we learn more.

I added a PathState::holepunched field that says whether or not that path was ever hole punched.

I added an Instant to the PathState::sent_ping field, so we can ensure that we don't prune paths that are currently attempting to holepunch, giving a very generous 30 seconds before deciding that the holepunch didn't work.

Right now we:

• keep paths that are open
• keep paths that are waiting to be opened
• keep paths that have not ever been pinged
• keep paths that are inactive but have hole punched before
• keep paths that are attempting to hole punch currently
• have at least one source that was given to us less that 2 mins ago

This means:

• we only prune paths if they are inactive, have never successfully holepunched, and have not been given to us or connected in over 2 mins

Also, we only do prune this if there are more that 20 inactive paths open.

I've added prune_ip_paths every time we call insert the EndpointActorState::paths.

[github-actions]

Documentation for this PR has been generated and is available at: https://n0-computer.github.io/iroh/pr/3666/docs/iroh/

Last updated: 2025-11-21T17:17:19Z

[github-actions]

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Last updated for commit: 2492e77