From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 08 Sep 2015 18:24:06 GMT
Subject: Re: Questions about git-push for huge repositories
Message-ID: <xmqq4mj493cp.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20150908054432.GC26331@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> If you turn on reachability bitmaps, git _will_ do the thorough set
> difference, because it becomes much cheaper to do so. E.g., try:
>
>     git repack -adb
>
> in repo A to build a single pack with bitmaps enabled. Then a subsequent
> push should send only a single object (the new commit).

Hmph, A has the tip of B, and has a new commit B hasn't seen but A
knows that new commit's tree matches the tree of the tip of B.

Wouldn't --thin transfer from A to B know to send only that new
commit object without sending anything below the tree in such a
case, even without the bitmap?