From owner-freebsd-arch@FreeBSD.ORG Thu Jan 15 11:00:15 2004 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F2B8F16A4CF; Thu, 15 Jan 2004 11:00:14 -0800 (PST) Received: from kientzle.com (h-66-166-149-50.SNVACAID.covad.net [66.166.149.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id AFA8643D5E; Thu, 15 Jan 2004 11:00:08 -0800 (PST) (envelope-from kientzle@acm.org) Received: from acm.org ([66.166.149.54]) by kientzle.com (8.12.9/8.12.9) with ESMTP id i0FJ08kX079534; Thu, 15 Jan 2004 11:00:08 -0800 (PST) (envelope-from kientzle@acm.org) Message-ID: <4006E337.7000404@acm.org> Date: Thu, 15 Jan 2004 11:00:07 -0800 From: Tim Kientzle User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.4) Gecko/20031006 X-Accept-Language: en-us, en MIME-Version: 1.0 To: David Schultz References: <4004D445.7020205@acm.org> <20040115182532.GA26149@VARK.homeunix.com> In-Reply-To: <20040115182532.GA26149@VARK.homeunix.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit cc: freebsd-arch@FreeBSD.ORG Subject: Re: Request for Comments: libarchive, bsdtar X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: kientzle@acm.org List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Jan 2004 19:00:15 -0000 David Schultz wrote: > On Tue, Jan 13, 2004, Tim Kientzle wrote: > > Nice! I'm sure [libarchive] will be immensely useful when finished. It should be useful now. > I have a few pseudorandom comments: > > - Have you considered extending the API such that it is able to > efficiently support random access archive formats? Yes, and I've chosen not to go that way. In short, random-access is a different problem: tar/gzip and tar/bzip2 do not support random-access at all; uncompressed tar archives do not cleanly support updates; tape drives/stdin/stdout/sockets do not support random access. Random access gains you some things, loses you others. In short, libarchive is for "streaming archive formats." On the other hand, many archive formats can be handled via streaming: it should be possible for libarchive to read zip archives, for example. (However, compressed zip archives can't be written in a pure streaming mode.) > - The HTTP and FTP support in libarchive(3) seems superfluous. Okay, it's gone. > - When this is done, I'm wondering what potential impact it might > have on sysinstall and the archive format it uses... Sysinstall uses tar/gzip format, libarchive reads tar/gzip format. This may potentially impact the implementation of sysinstall (which could unpack the base system itself rather than running a separate tar), but I see no potential impact on sysinstall's choice of archive format. Tim