some way to refresh in-memory packed refs cache without relying on mtime

[yuja]

Summary 💡

Does it make sense to add API to trigger RefStore::force_refresh_packed_buffer() or make it public?

Motivation 🔦

In jj, gc is implemented as a combination of internal ref cleanup through gix API + shelling out git gc command. Since git gc will move loose refs to packed-refs, I want to ensure that the in-memory packed cache is invalidated. mtime isn't reliable if git gc is super fast.

https://github.com/martinvonz/jj/blob/77eaf67f96c6ea438e2dd1a5636f34b6a321e6be/lib/src/git_backend.rs#L1213

[Byron]

Thanks for bringing this up!

I have implemented this in f2d8955 which will definitely be merged within a month or less. Edit: It will be merged very soon to fix the cargo-deny based CI failure as well.

[Byron]

Closing, as the branch was merged and the method will be available with the next release. Please feel free to leave additional comments or reopen as you see fit.