Mailing-List: contact cygwin-apps-help AT sourceware DOT cygnus DOT com; run by ezmlm
Sender: cygwin-apps-owner AT sourceware DOT cygnus DOT com
List-Subscribe: <mailto:cygwin-apps-subscribe AT sources DOT redhat DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin-apps/>
List-Post: <mailto:cygwin-apps AT sources DOT redhat DOT com>
List-Help: <mailto:cygwin-apps-help AT sources DOT redhat DOT com>, <http://sources.redhat.com/lists.html#faqs>
Delivered-To: mailing list cygwin-apps AT sources DOT redhat DOT com
Message-ID: <002d01c17706$fe385ba0$0200a8c0@lifelesswks>
From: "Robert Collins" <robert DOT collins AT itdomain DOT com DOT au>
To: <cygwin-apps AT cygwin DOT com>
References: <093e01c1745c$aece3f50$0200a8c0 AT lifelesswks> <20011127045848 DOT GB16578 AT redhat DOT com>
Subject: Re: recoverable downloads - opinions sought
Date: Tue, 27 Nov 2001 16:47:24 +1100
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
X-OriginalArrivalTime: 27 Nov 2001 05:47:20.0732 (UTC) FILETIME=[FAFA95C0:01C17706]

----- Original Message -----
From: "Christopher Faylor" <cgf AT redhat DOT com>
To: <cygwin-apps AT cygwin DOT com>
Sent: Tuesday, November 27, 2001 3:58 PM
Subject: Re: recoverable downloads - opinions sought


> On Sat, Nov 24, 2001 at 07:23:15AM +1100, Robert Collins wrote:
> >To do recoverable downloads we need 2 things.
> >1) A way to check the file, other than filesize, for integrity. MD5
will
> >do and IIRC that's already caclulated on sources.redhat.
> >2) Code to pickup partway through and carry on.
> >
> >For 2) we can either code it internally, or link statically to
something
> >like libcurl, or call out to wget/curl.
>
> I don't understand why we need an external library for this.  Isn't
this
> just a simple "start here when downloading" type of operation?  I know
that
> the ftp protocol allows this.  I'm not sure about http.

FTP/HTTP/fileio/any other protocols we support in the future should all
support this to some extent or another. It's more a duplication of
effort thing really, I don't really like writing YAFC and YAHC when good
clients are in libraries already, and with C++ bindings we can save time
and effort.

As for the code complexity, FTP *optionally* supports the REST command,
but some FTP servers don't, so it cannot be assumed. As for HTTP, the
server as the option to return the entire file anyway, and there are
(IIRC) 3 different ways the response can be addressed. Se above on
duplication of effort.

Rob