Re: [PATCH 2/2] for-each-ref: add --count-matches option

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 26, 2023, 16:14 UTC
Message-ID: <xmqqbkh25hfr.fsf@gitster.g>
In-Reply-To: <9121e027fb9f157878a9624ce6c834b69cd38472.1687792197.git.gitgitgadget@gmail.com>

"Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:

Show 6 quoted lines

> Each of these approaches is wasteful as it requires sending the list of
> matching reference names across a pipe plus the cost of parsing that
> output.
>
> Instead, it would be helpful to have a Git command that counts the
> number of refs matching a list of patterns.

For for-each-ref (which can be reused by branch and tag for no cost), I am on the fence but slightly in favor (partly because the code has already been written). But I have to wonder where changes that come from the above reasoning need to end, though.

Do we count branches and tags because "git branch --list | wc -l" is too costly? Should we teach "git remote" the same trick? How about "git stash list"? "git show-index $pack_index"? "git ls-files"?

How do we decide where to draw the line? When a command invocation in a large repository can produce records exceeding a million?