Run git gc periodically on the crates.io index

[ohaddahan]

@Kixiron @jyn514 @pietroalbini

Deleted my fork and restart my changes, also separated them into smaller chunks.

Hopefully I got understood and implemented your comments properly.

(#956)

[jyn514]

Looks very nice :)

[ohaddahan]

BTW, maybe we should add some logging on success too, just to be sure it's actually working as expected.
What do you think?

docs.rs/src/index/mod.rs

Line 78 in 508a9d0

pub fn run_git_gc(&self) {

[jyn514]

Sounds good to me. Time for another PR? 😆

[Byron]

It's my stated goal to as-soon-as-reasonable switch crates-index-diff over to use gitoxide, the main motivation being slightly faster pulls and smart-gc. I have been bitten by this myself more than once, and believe this pitfall shouldn't be one anymore.

I was thinking that we really want to run GC if there are too many packs, and too many really means more than we are allowed to open as per the file handle limit. What if gitoxide would track the amount of open handles and GC automatically when they run out. The GC could also be optimized to do only minimal work in favor of producing a combined pack fast, which from what I know now is totally possible.

Here is the tracking issue for feedback, comments and general brainstorming.