Re: post-fetch, tweak-fetch hook

From: Seth Robertson <in-gitvger@baka.org>
Date: May 6, 2012, 23:10 UTC
Message-ID: <201205062310.q46NAHnM022630@no.baka.org>
In-Reply-To: <CAKLmikNaqVRb=pGUhbvVQTX2tYWT0HSS2R6Ezmico3X0rMgvYQ@mail.gmail.com>

In message <CAKLmikNaqVRb=pGUhbvVQTX2tYWT0HSS2R6Ezmico3X0rMgvYQ@mail.gmail.com>, Mitar writes:

    I am a git newbie, but after few hours or reading and searching I have
    not found a simple way to get a list of revisions retrieved by a
    fetch

The output of fetch seems to do that, quite nicely.

----------------------------------------------------------------------

> git fetch

remote: Counting objects: 24155, done.
remote: Compressing objects: 100% (6651/6651), done.
remote: Total 21446 (delta 15831), reused 20146 (delta 14640)
Receiving objects: 100% (21446/21446), 6.78 MiB | 239 KiB/s, done.
Resolving deltas: 100% (15831/15831), completed with 574 local objects.
From git://git.kernel.org/pub/scm/git/git
   ea2c69e..edf1412  maint      -> origin/maint
   ae4479d..8275905  master     -> origin/master
 + b6b16ad...8a79d96 next       -> origin/next  (forced update)
 + 47db9a0...30b8c95 pu         -> origin/pu  (forced update)
   ce29fc8..3ca5cbc  todo       -> origin/todo
----------------------------------------------------------------------

OK, ignoring that output:

----------------------------------------------------------------------

> git branch -r | grep -v ' -> ' | while read b; do git reflog -n 1 "$b"; done

edf1412 refs/remotes/origin/maint@{0}: fetch: fast-forward ea2c69e 8275905 refs/remotes/origin/master@{0}: fetch: fast-forward ae4479d 8a79d96 refs/remotes/origin/next@{0}: fetch: forced-update b6b16ad 30b8c95 refs/remotes/origin/pu@{0}: fetch: forced-update 47db9a0 3ca5cbc refs/remotes/origin/todo@{0}: fetch: fast-forward ----------------------------------------------------------------------

The reflog, of course, only gives you the latest change for each branch, which means that two fetches in a row will return the same output if no changes were received. Of course there is the classic:

---------------------------------------------------------------------- git for-each-ref | pcregrep 'commit\srefs/remotes/' > /tmp/old git fetch git for-each-ref | pcregrep 'commits\srefs/remotes/' > /tmp/new diff /tmp/old /tmp/new ----------------------------------------------------------------------

I'm in favor of more git hooks myself, but there is a solution to your needs without it.

    Even if there is a way to reconstruct data passed to post-receive (to
    be given to post-fetch), I am concerned about race-condition of this.

If you care about race conditions (and really, a lockfile(1) call can take care of that easily enough), then parse the output of fetch which will make it clear what *this* call did.

					-Seth Robertson