[10204] in www-talk@info.cern.ch
Re: Entity Tags
daemon@ATHENA.MIT.EDU (Paul Hethmon)
Mon Aug 12 14:11:22 1996
To: Gavin Button <gavinb@imaging.co.uk>, "'www-talk@w3.org'" <www-talk@w3.org>
Date: Mon, 12 Aug 1996 14:01:48 EST
From: Paul Hethmon <phethmon@utk.edu>
Reply-To: Paul Hethmon <phethmon@utk.edu>
Resent-From: www-talk@w3.org
Addressed to: Gavin Button <gavinb@imaging.co.uk>
"'www-talk@w3.org'" <www-talk@w3.org>
** Reply to note from Gavin Button <gavinb@imaging.co.uk> Mon, 12 Aug 1996 17:02:01 +-100
> I am in the process of designing an HTTP 1.1 server which provides
> JPEG Images when a GET method with a certain URL is received, but am unsure
> about the use of entity tags. Should an entity of this type respond with an ETag
> field ? In turn, should I support If-Match/If-None-Match? If so ,How?
Yes.
Yes. If you're going to supply an Etag then you need to support
If-Match and If-None-Match. There's no need for an Etag unless you
do since the client request must use those headers to make
conditional requests.
Just match on the Etag when a request comes in. The Etag is an
opaque identifier to the sender, so you may use any unique id
for the image.
Just remember to allow for *both* If-Match and If-None-Match
headers in the same request. It's also possible, although stupid,
that you may receive the same Etag in both headers by a
confused client/proxy.
Paul
Paul Hethmon
phethmon@utk.edu
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