W3C home > Mailing lists > Public > ietf-http-wg@w3.org > January to March 2009

Re: Review of Content-Encoding: value token

From: Mark Nottingham <mnot@mnot.net>
Date: Fri, 30 Jan 2009 18:48:49 +1100
Cc: "Roy T. Fielding" <fielding@gbiv.com>, Carine Bournez <carine@w3.org>, ietf-http-wg@w3.org
Message-Id: <5FA061FD-BC76-4A01-A9F2-9F3050F1F385@mnot.net>
To: Julian Reschke <julian.reschke@gmx.de>

My concern is that many implementations treat content-coding like  
transfer-codings, in some ways; that is, they layer it in  
automatically (e.g., mod_gzip). The confluence of this with things  
like byteranges, etag comparison, etc. may be quite prone to bugs.

You'd also start to get into discussions like "can't JPEG just be a  
content-coding of GIF?" and so forth. The media type system isn't  
perfect by any means, but I think it's a better fit for this type of  


On 23/01/2009, at 5:07 PM, Julian Reschke wrote:

> Mark Nottingham wrote:
>> Yes. If it doesn't preserve characters, all sorts of mess can  
>> result, e.g., with ETag comparison, range retrieval, etc.
> > ...
> I was looking at <http://greenbytes.de/tech/webdav/rfc2616.html#rfc.section.3.5 
> >...:
> "Content coding values indicate an encoding transformation that has  
> been or can be applied to an entity. Content codings are primarily  
> used to allow a document to be compressed or otherwise usefully  
> transformed without losing the identity of its underlying media type  
> and without loss of information."
> ...and was asking myself: is perfect reconstruction of the original  
> payload really required? Is there something we need to fix here?
> BR, Julian

Mark Nottingham     http://www.mnot.net/
Received on Friday, 30 January 2009 07:49:31 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 1 March 2016 11:10:48 UTC