From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Pitre Subject: Re: cleaner/better zlib sources? Date: Fri, 16 Mar 2007 13:12:46 -0400 (EDT) Message-ID: References: <45F9EED5.3070706@garzik.org> <45FAC75B.3030902@garzik.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=us-ascii Content-Transfer-Encoding: 7BIT Cc: Linus Torvalds , Davide Libenzi , Git Mailing List , mpm@selenic.com, bcrl@kvack.org To: Jeff Garzik X-From: git-owner@vger.kernel.org Fri Mar 16 18:12:52 2007 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1HSFz1-0007xa-Do for gcvg-git@gmane.org; Fri, 16 Mar 2007 18:12:51 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965693AbXCPRMs (ORCPT ); Fri, 16 Mar 2007 13:12:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965712AbXCPRMs (ORCPT ); Fri, 16 Mar 2007 13:12:48 -0400 Received: from relais.videotron.ca ([24.201.245.36]:45876 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965693AbXCPRMr (ORCPT ); Fri, 16 Mar 2007 13:12:47 -0400 Received: from xanadu.home ([74.56.106.175]) by VL-MO-MR002.ip.videotron.ca (Sun Java System Messaging Server 6.2-2.05 (built Apr 28 2005)) with ESMTP id <0JF0006FGAHAQ6A0@VL-MO-MR002.ip.videotron.ca> for git@vger.kernel.org; Fri, 16 Mar 2007 13:12:47 -0400 (EDT) In-reply-to: <45FAC75B.3030902@garzik.org> X-X-Sender: nico@xanadu.home Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: On Fri, 16 Mar 2007, Jeff Garzik wrote: > Although it sounds like zlib could indeed be optimized to reduce its startup > and shutdown overhead, I wonder if switching compression algorithms to a pure > Huffman or even RLE compression (with associated lower startup/shutdown costs) > would perform better in the face of all those small objects. > > And another random thought, though it may be useless in this thread: I bet > using a pre-built (compiled into git) static zlib dictionary for git commit > and tree objects might improve things a bit. See my last post. We'll do even better with special object encoding altogether. Those representations are so dense that compression provides no gain at all making the point moot. Nicolas