I have an utility in Go that runs commits checkouts via os/exec and then does some operations on files from the commit.
I suspect that at the moment this command returns its return code:
_, err := exec.Command("git", "-C", sourceDir, "checkout", hash).Output()
The whole file tree is up to date in the folder and I can do whatever I want with the files, without the need to wait for some operations to finish in background.
What if it's a very large repository, where one commit differs much from another one and it takes time to sync deleted/added/modified files when switching from one commit to another?
Can I run my operations right after git checkout returns 0?
git checkout does not exit until the checkout is completed (or has failed).
Comments about auto-gc in the background are not particularly relevant here, since auto-gc is not related to whether the checkout has finished. For that matter, git checkout does not run git gc --auto: there is no point since git checkout does not create new Git objects. A reasonably current list of things that do invoke git gc --auto (as of about 2.18) is:
git amgit commitgit fetchgit mergegit receive-pack (servers)git rebase