From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Keeping Subject: Re: [PATCH 0/2] finding the fork point from reflog entries Date: Thu, 24 Oct 2013 22:40:07 +0100 Message-ID: <20131024214007.GE10779@serenity.lan> References: <1382641884-14756-1-git-send-email-gitster@pobox.com> <20131024205434.GC10779@serenity.lan> <20131024213134.GD10779@serenity.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org, Martin von Zweigbergk , Jonathan Nieder To: Junio C Hamano X-From: git-owner@vger.kernel.org Thu Oct 24 23:40:24 2013 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1VZSdj-0002Ph-K1 for gcvg-git-2@plane.gmane.org; Thu, 24 Oct 2013 23:40:24 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755233Ab3JXVkT (ORCPT ); Thu, 24 Oct 2013 17:40:19 -0400 Received: from coyote.aluminati.org ([72.9.247.114]:41566 "EHLO coyote.aluminati.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753090Ab3JXVkT (ORCPT ); Thu, 24 Oct 2013 17:40:19 -0400 Received: from localhost (localhost [127.0.0.1]) by coyote.aluminati.org (Postfix) with ESMTP id 6CA2E606514; Thu, 24 Oct 2013 22:40:18 +0100 (BST) X-Virus-Scanned: Debian amavisd-new at caracal.aluminati.org X-Spam-Flag: NO X-Spam-Score: -2.9 X-Spam-Level: X-Spam-Status: No, score=-2.9 tagged_above=-9999 required=6.31 tests=[ALL_TRUSTED=-1, BAYES_00=-1.9] autolearn=ham Received: from coyote.aluminati.org ([127.0.0.1]) by localhost (coyote.aluminati.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id noZ1spGifl9R; Thu, 24 Oct 2013 22:40:16 +0100 (BST) Received: from serenity.lan (banza.aluminati.org [10.0.7.182]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by coyote.aluminati.org (Postfix) with ESMTPSA id B1F656064FD; Thu, 24 Oct 2013 22:40:09 +0100 (BST) Content-Disposition: inline In-Reply-To: <20131024213134.GD10779@serenity.lan> User-Agent: Mutt/1.5.22 (2013-10-16) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Thu, Oct 24, 2013 at 10:31:35PM +0100, John Keeping wrote: > On Thu, Oct 24, 2013 at 02:20:29PM -0700, Junio C Hamano wrote: > > John Keeping writes: > > > > > On Thu, Oct 24, 2013 at 12:11:22PM -0700, Junio C Hamano wrote: > > >> The first one is a clean-up of the code to parse command line > > >> options to "git merge-base". Options such as "--independent", > > >> "--is-ancestor" and "--octopus" are mutually exclusive and it is > > >> better expressed in terms of the recently introduced OPT_CMDMODE. > > >> > > >> The second one implements the entire logic of the for loop we see in > > >> "git pull --rebase" directly using get_merge_bases_many() and > > >> postprocessing the result. > > > > > > Nice! I tried this in the case where the target commit happens to be > > > the 63rd reflog entry: > > > > > > $ time sh -c 'for rev in $(git rev-list -g origin/master 2>/dev/null) > > > do > > > git merge-base --is-ancestor $rev b2edae0 && break > > > done > > > ' > > > > > > real 0m3.772s > > > user 0m3.338s > > > sys 0m0.440s > > > > > > $ time git merge-base --reflog origin/master b2edae0 > > > > > > real 0m0.156s > > > user 0m0.138s > > > sys 0m0.018s > > > > The real question is if the C code computes the same as the shell > > loop. > > And in fact it doesn't - if you replace the "break" with "echo $rev" the > shell version prints b2edae0... but the C version prints nothing (and > exists with status 1). To clarify: the particular commit in the calls above happens to be the oldest entry in the reflog, if I pick a newer entry then it works. It seems that for_each_reflog_ent isn't returning the oldest entry; revs.nr is 62 whereas "git rev-list -g origin/master | wc -l" gives 63.