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Comment by romka2 | Hacker News Reader

The job of gitstatusd is to put Git status in your shell prompt. See screenshot at the top of https://github.com/romkatv/gitstatus. This is an amazingly convenient tool.

When you are working on chromium, on every command you type gitstatusd needs to list the contents of 25,000 directories. Low level optimizations like the ones described here are what makes gitstatusd 10 times faster than `git status`, which in turn makes prompt responsive when otherwise it would be sluggish.

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Isn't inotify meant for exactly this kind of thing, though? You are already introducing a hard dependency on Linux syscalls in "v4" of the optimisations, so it would seem advantageous to make use of that to avoid the full directory traversal for most of the time.

This directory-listing code only executes on a "cold" run of gitstatusd, which happens when you `cd` into a repo for the first time. Users obviously can tolerate higher prompt latency in this case but faster is still better.

inotify requires you to hold open fds for all the dirs and files you're watching iirc, so in repos that large, you'll be crushed by the file-descriptor-per-process limit.

It doesn't, you might need to tweak its limits via /proc/sys/fs/inotify/max_* on such repositories, but those limits are not the same as the much lower open FD limits (as in ulimit -n ...).

I've posted some details explaining why gitstatusd doesn't use inotify in https://github.com/romkatv/gitstatus/commit/050aaaa04b652e15.... The short version is that the default max_user_watches limit is much too low to be useful for gitstatusd and I cannot ask or expect users to change their system settings.

Your documentation indicates that you've tried with core.untrackedCache, but have you tried core.fsmonitor with the watchman hook?

Obviously your "gitstatus" is still generally useful, but if your main itch you're trying to scratch is to have a faster "status" in a particular repo then you should be able to get that down to a few milliseconds with "git status", if you're willing to have watchman sit in the background and monitor it.

> [...] have you tried core.fsmonitor with the watchman hook?

I read the docs but it seems like it's not something I can enable on users' machines. Or maybe there is a way to take advantage of it even if it's not enabled? I really haven't looked much into it.

To clarify, my main motivation isn't to make my own prompt latency low (I don't even work on large git projects) but to make Powerlevel10k as good a product as possible. Git latency is a pain point for the existing users, so I work on optimizing it.

I also cannot rely on users to enable untracked cache even if their filesystem allows it. So gitstatusd performs tests similar to `git update-index --test-untracked-cache` in the background and builds its own untracked cache if tests pass. This makes for a good user experience with no setup or configuration fiddling.

You could use it if available, and fall back to existing behavior if not. (Not sure if it would be faster, but probably worth experimenting with.)

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