From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: newbie questions about git design and features (some wrt hg) Date: Tue, 30 Jan 2007 20:35:02 -0800 (PST) Message-ID: References: <3c6c07c20701300820l42cfc8dbsb80393fc1469f667@mail.gmail.com> <7v8xfkz8oj.fsf@assigned-by-dhcp.cox.net> <3c6c07c20701301938u4d1503a2m3e0af51121b8e6db@mail.gmail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: git@vger.kernel.org To: Mike Coleman X-From: git-owner@vger.kernel.org Wed Jan 31 05:35:16 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 1HC7Bi-00068y-R3 for gcvg-git@gmane.org; Wed, 31 Jan 2007 05:35:15 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932783AbXAaEfI (ORCPT ); Tue, 30 Jan 2007 23:35:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932787AbXAaEfI (ORCPT ); Tue, 30 Jan 2007 23:35:08 -0500 Received: from smtp.osdl.org ([65.172.181.24]:36718 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932783AbXAaEfG (ORCPT ); Tue, 30 Jan 2007 23:35:06 -0500 Received: from shell0.pdx.osdl.net (fw.osdl.org [65.172.181.6]) by smtp.osdl.org (8.12.8/8.12.8) with ESMTP id l0V4Z39V007790 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Tue, 30 Jan 2007 20:35:03 -0800 Received: from localhost (shell0.pdx.osdl.net [10.9.0.31]) by shell0.pdx.osdl.net (8.13.1/8.11.6) with ESMTP id l0V4Z226007375; Tue, 30 Jan 2007 20:35:02 -0800 In-Reply-To: <3c6c07c20701301938u4d1503a2m3e0af51121b8e6db@mail.gmail.com> X-Spam-Status: No, hits=-0.471 required=5 tests=AWL X-Spam-Checker-Version: SpamAssassin 2.63-osdl_revision__1.111__ X-MIMEDefang-Filter: osdl$Revision: 1.172 $ X-Scanned-By: MIMEDefang 2.36 Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: On Tue, 30 Jan 2007, Mike Coleman wrote: > > As for performance, my thinking was that since hg is implemented > apparently almost entirely in Python, and has (again apparently) > generally acceptable performance, this suggested that much of the > problem might be I/O-bound enough that language efficiency might not > matter so much. Note that git actually implements a lot more than hg does. hg depends on external programs (almost uniformly written in C) to do the actual diff generation, 3-way merging etc. Git actually ends up doing all of those internally, and minimizes external dependencies that way. More importantly, perhaps, it allows us to do a better job, faster. The early example of this is patch application, where git supports a much nicer patch format that can express renames etc in the patch. But I'll admit - my main reason going with C is (a) it's what I know and (b) I absolutely _hate_ being constrained by the language. The great thing about C (still) is that you can do *anything* in it. You're literally limited by hardware, and by your own abilities. Nothing else. Linus