W3C home > Mailing lists > Public > ietf-http-wg-old@w3.org > May to August 1996

Re: no-transform

From: <jg@w3.org>
Date: Thu, 06 Jun 96 12:50:43 -0400
Message-Id: <9606061650.AA01544@zorch.w3.org>
To: hardie@nasa.gov
Cc: jg@w3.org, fielding@liege.ICS.UCI.EDU, http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com, jg@w3.org
Ted writes:
>Jim writes: 
> Here is an attempt to rewrite this:
>> 
>
>I like the new direction of the language, as I think it makes clear
>the conditions under which a no-transform might be applied and why
>it must be obeyed. 
>
>The first paragraph is a little hard to parse, though.  How about
>the following as a re-write:
>
>  Intermediate caches (proxies) have found it useful to convert the
>  media type of certain entity bodies.  A proxy might, for example,
>  convert between image formats in order to save cache space or
>  to reduce the amount of traffic on a slow link.  HTTP has to date
>  been silent on these transformations.  Serious operational problems
>  do occur, however, when these transformations are applied to entity
>  bodies which are part of certain kinds of applications, and these
>  applications can fail as a result.
>
>I think this language still fits with the second paragraph and is
>little easier to follow.
>
>

Here is a third try, which I think is better than either my original or
Ted's rewrite.

 14.9.5 No-Transform Directive

  Intermediate caches (proxies) have found it useful to convert the
  media type of certain entity bodies.  A proxy might, for example,
  convert between image formats in order to save cache space or
  to reduce the amount of traffic on a slow link.  HTTP has to date
  been silent on these transformations.  

  Serious operational problems have already occured, however, when these 
  transformations have been applied to entity bodies intended for certain 
  kinds of applications.  For example, applications for  medical imaging, 
  scientific data analysis and those using end-to-end authentication, 
  all require that the original entity-body be reproduced exactly bit for bit.
  Therefore, an intermediate cache MUST NOT change the
  media type of an entity-body if the response includes the no-transform
  directive.
Received on Thursday, 6 June 1996 09:54:01 EDT

This archive was generated by hypermail pre-2.1.9 : Wednesday, 24 September 2003 06:32:03 EDT