From mboxrd@z Thu Jan 1 00:00:00 1970 From: A Large Angry SCM Subject: Re: Notes on supporting Git operations in/on partial Working Directories Date: Sun, 17 Sep 2006 14:11:46 -0700 Message-ID: <450DBA12.3070700@gmail.com> References: <4509A7EC.9090805@gmail.com> <7vu03a2po8.fsf@assigned-by-dhcp.cox.net> <4509B954.60101@gmail.com> <7v8xkl26kb.fsf@assigned-by-dhcp.cox.net> <450AEDBF.9050307@gmail.com> <7vvenm3h9f.fsf@assigned-by-dhcp.cox.net> <450D9847.4080308@gmail.com> <450DA99F.8000009@gmail.com> Reply-To: gitzilla@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: git@vger.kernel.org X-From: git-owner@vger.kernel.org Sun Sep 17 23:11:56 2006 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by ciao.gmane.org with esmtp (Exim 4.43) id 1GP3vd-0003un-DA for gcvg-git@gmane.org; Sun, 17 Sep 2006 23:11:53 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965103AbWIQVLu (ORCPT ); Sun, 17 Sep 2006 17:11:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965104AbWIQVLu (ORCPT ); Sun, 17 Sep 2006 17:11:50 -0400 Received: from py-out-1112.google.com ([64.233.166.180]:13689 "EHLO py-out-1112.google.com") by vger.kernel.org with ESMTP id S965103AbWIQVLu (ORCPT ); Sun, 17 Sep 2006 17:11:50 -0400 Received: by py-out-1112.google.com with SMTP id n25so5043180pyg for ; Sun, 17 Sep 2006 14:11:49 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:disposition-notification-to:date:from:reply-to:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=HFwDjL+/GrAxnHgLdlOVi83f9cgoAYfp5KWBCwMVMYmIRKnHLIUltW57sAODiu8CKb70rHB4rr5jG25huChoYZqVAMaww8pc/mzOVJHsi4KIdQHmlLHPRFo0rSUuS43EHyrq5gmfcr6DvVDrgsNFtH0G/Xb2RDeBdamCDcPYKeI= Received: by 10.65.51.16 with SMTP id d16mr14677358qbk; Sun, 17 Sep 2006 14:11:49 -0700 (PDT) Received: from ?10.0.0.6? ( [67.20.86.89]) by mx.gmail.com with ESMTP id e15sm10269qba.2006.09.17.14.11.47; Sun, 17 Sep 2006 14:11:48 -0700 (PDT) User-Agent: Thunderbird 1.5.0.5 (X11/20060725) To: Jakub Narebski In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: Jakub Narebski wrote: > A Large Angry SCM wrote: >> Jakub Narebski wrote: >>> A Large Angry SCM wrote: >>> >>>> There is no fundamental reason Git can not support partial >>>> checkouts/working directories. In fact, there is no fundamental reason >>>> Git can not support operations on partial (sparse?) repositories in both >>>> space (working content/state, etc.) and time (history); it's just a >>>> matter of record keeping[*1*]. That isn't how the Linux kernel >>>> developers want to use their VCS but it _is_ how others want to use >>>> theirs. >>> There is perhaps not much trouble with partial checkouts, but there is >>> problem with partial _commits_, at least for snapshot based SCM >>> (as opposed to patchset based SCM). >> By "partial commit" I take it you mean a commit with only partial >> information about the new (content) state? If so, the missing >> information about the new state can be assumed to have not changed from >> the previous recorded state (commit). > > That of course assumes that 1) the whole state is recorded somewhere > (perhaps in the repository); so the partial checkout saves space only if > repository compress really well, 2) there are no merges outside checked out > part. 1) The TREE objects leading to the objects that are added/deleted/changed objects are required. TREEs not leading to the added/deleted/changed objects are not required, only their IDs. That is sufficient to commit the changes in a partial checkout. 2) Obviously, only the part checked out can be worked on. If you want to merge changes to some other part, you will need that part, and possibly a mergebase.