From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: [RFC] pack-objects: compression level for non-blobs Date: Sat, 29 Dec 2012 00:07:07 -0500 Message-ID: <20121229050707.GA14475@sigill.intra.peff.net> References: <1353911154-23495-1-git-send-email-b@rr-dav.id.au> <20121229004104.GA24828@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: David Michael Barr , Git Mailing List To: Nguyen Thai Ngoc Duy X-From: git-owner@vger.kernel.org Sat Dec 29 06:07:33 2012 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 1Toodv-0007nT-Vk for gcvg-git-2@plane.gmane.org; Sat, 29 Dec 2012 06:07:32 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751070Ab2L2FHM (ORCPT ); Sat, 29 Dec 2012 00:07:12 -0500 Received: from 75-15-5-89.uvs.iplsin.sbcglobal.net ([75.15.5.89]:38469 "EHLO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750719Ab2L2FHL (ORCPT ); Sat, 29 Dec 2012 00:07:11 -0500 Received: (qmail 26981 invoked by uid 107); 29 Dec 2012 05:08:20 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) (smtp-auth username relayok, mechanism cram-md5) by peff.net (qpsmtpd/0.84) with ESMTPA; Sat, 29 Dec 2012 00:08:20 -0500 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Sat, 29 Dec 2012 00:07:07 -0500 Content-Disposition: inline In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Sat, Dec 29, 2012 at 11:34:09AM +0700, Nguyen Thai Ngoc Duy wrote: > On Sat, Dec 29, 2012 at 7:41 AM, Jeff King wrote: > > I wonder if we could do even better, though. For a traversal, we only > > need to look at the commit header. We could potentially do a progressive > > inflate and stop before getting to the commit message (which is the bulk > > of the data, and the part that is most likely to benefit from > > compression). > > Commit cache should solve this efficiently as it also eliminates > parsing cost. We discussed this last time as a side topic of the > reachability bitmap feature. I agree that a commit cache would solve this (though it can not help the tree traversal). But just dropping the compression (or doing partial decompression when we only care about the beginning part) is way less code and complexity. There's no cache to manage. -Peff