From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Pavel Raiskup" Subject: Re: Histogram diff, libgit2 enhancement, libgit2 => git merge (GSOC) Date: Tue, 22 Mar 2011 13:32:48 +0100 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit To: "git@vger.kernel.org" X-From: git-owner@vger.kernel.org Tue Mar 22 13:33:38 2011 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Q20mH-0007iF-H3 for gcvg-git-2@lo.gmane.org; Tue, 22 Mar 2011 13:33:37 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755895Ab1CVMdU (ORCPT ); Tue, 22 Mar 2011 08:33:20 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:64813 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755887Ab1CVMdT (ORCPT ); Tue, 22 Mar 2011 08:33:19 -0400 Received: by fxm17 with SMTP id 17so6366940fxm.19 for ; Tue, 22 Mar 2011 05:33:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:content-type:in-reply-to:references:subject:to :date:mime-version:content-transfer-encoding:from:message-id :user-agent; bh=F+9OsFFT72nrqia52HzE2s98nk2qFiOIF1YbMi59rYI=; b=hCyGimZd3B+c9tdbs5ZP+zXNyArC5ZD0vPd6SdnXtc76/e3cW6BGMa5nF+OJ4JOpYv U/+dP854H9kCOiEY/QaHVEJisNOl4d+tr5JK51Ma1GMfCYX7GEaVt/4FdyC2sux/Nm2j e3bRY/Acwh28ouIVFsKwgBSCnN5TPaofYuY0w= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=content-type:in-reply-to:references:subject:to:date:mime-version :content-transfer-encoding:from:message-id:user-agent; b=SvDwdX3RapC6XZDOY95Ijau3O+xq9Eu+4DvVbi7hhP+xbrA4e1GS0keUlKayKm63tu F729cTAbw+DjghhzS1a8NzyHurzwrXg4Ubk1QHQosf/+evZ+lTApxy/w1DQ3CzJayp5b 1SVahJqD2urd+21v8VZy2FdPe0wokB2gmHauA= Received: by 10.223.101.72 with SMTP id b8mr2296056fao.15.1300797190516; Tue, 22 Mar 2011 05:33:10 -0700 (PDT) Received: from localhost.localdomain (dhcps190.fit.vutbr.cz [147.229.179.190]) by mx.google.com with ESMTPS id f15sm2517881fax.10.2011.03.22.05.33.06 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 22 Mar 2011 05:33:07 -0700 (PDT) In-Reply-To: User-Agent: Opera Mail/11.01 (Linux) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: >> Histogram diff: >> There is no mentor mentioned in [1]. Does it mean that there is no person >> .. > > As the original author of HistogramDiff in JGit, and a contributor to > C Git... I'm probably the best person to mentor this task. I'm really > busy, so I didn't sign up to mentor anything else this year, but I > think I would make time for this project. Thanks for your answer and for your ability to be a mentor of this task. >> There is a goal "Get this feature merged to the upstream git." -- but I have >> one theoretical question -- what if the benchmarking/study of histogram diff >> leads to conclusion that this algorithm will not be useful for upstream? > > Then the project doesn't merge. :-) > >> Does it mean "fail" in terms of GSOC? I have to think about it even if it >> looks that there should be speedup quite obvious. I don't want to fail >> a priory :). > > I don't think so > > I think the success of this project is if the code is of the quality > that upstream would accept it, and if the final analysis data makes it > clear whether or not its worth including. Its probably not worth > including if its the same speed as the current Myers diff > implementation from libxdiff or slower. But if its 2x faster, its > probably worth merging. If the code quality is acceptable to the > upstream maintainers. I wanted to know exactly this kind of information. Of course I don't want to make a code of unacceptable quality from any perspective. And I think that you probably don't expect histogram diff to be significantly faster in general :) Thanks again - it is good to know that you as author of histogram diff are here. And sorry for my latency .. [ot] this is because of hectic school schedule now - which is actually not good :( I need to study git source very deeply _NOW_ (I wanted to reply earlier but..) [/ot] Thanks to Junio C Hamano with almost the same answer here: http://thread.gmane.org/gmane.comp.version-control.git/169498/focus=169516 Pavel >> [1] https://git.wiki.kernel.org/index.php/SoC2011Ideas