From mboxrd@z Thu Jan  1 00:00:00 1970
MIME-version: 1.0
Content-transfer-encoding: 7BIT
Content-type: text/plain
Date: Tue,  9 Jun 2009 10:14:13 -0700
From: Roman V Shaposhnik <rvs@sun.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Message-id: <1244567653.9958.1733.camel@work>
Subject: [9fans] Different representations of the same file/resource in a
	synthetic FS
Topicbox-Message-UUID: 07d05a36-ead5-11e9-9d60-3106f5b1d025

Working on a RESTful API lately (which is as close to working on a 9P
filesystem as I can get these days) I've been puzzling over this issue:
is content negotiation a good thing or a bad thing? Or to justify
posting to this list: what would be the proper 9P way of not only
representing different "renditions" of the same information in
a synthetic filesystem but also give consumer a chance to declare
*a set* of preferred ones.

Lets assume a classical example (modified slightly to fit 9P):
a synthetic filesystem that serves images from a web cam.
The very same frame can be asked for in different formats
(.gif, .png, .pdf, etc.). Is serving
   /<date>/<time>/<camera-id>/gif/frame
   /<date>/<time>/<camera-id>/png/frame
   ...
   /<date>/<time>/<camera-id>/pdf/frame
and relying on reading
   /<date>/<time>/<camera-id>
for the list of "supported" representations really better
than what HTTP content negotiation offers?

Thanks,
Roman.