Re: [Feature Request] Allow batch removal of remotes with 'git remote remove'

Jeff King [off-list ref] writes:

On Wed, Jan 22, 2025 at 02:24:38AM +0000, brian m. carlson wrote:

quoted

Because `git remote remove` will remove remote-tracking branches and
their reflogs, we typically will want to do that all at once in a single
ref transaction, and hence in one command.  Not doing so performs very
poorly (as does, notably `git remote rename`[0]) when all of the refs are
packed.  If you have a large number of remotes to delete and a large
number of total refs, this will perform really badly indeed, since the
operation of rewriting the packed-refs file becomes quadratic.

The removal of the remote-tracking branches is also the reason that
editing the config isn't sufficient, either.

I think the config update is probably quadratic, too (in the number of
remotes). Each one is going to rewrite the whole config file, minus its
matching section. But a "remove" operation that took multiple remotes
could do it all in a single pass.

If somebody does implement "remote remove" that takes multiple names, I
hope they'll refactor to do all of the operations in a single pass, and
not just loop on builtin/remote.c:rm() internally.

Probably git-config could stand to learn similar tricks, too. There is
"--remove-section", but I don't think you can pass multiple sections
(and it's likewise quadratic).

Thanks for bringing up the performance aspect and where the problem
lies in the current implementation.