On 08/10/2011 09:29 PM, Amos Jeffries wrote: > On Thu, 11 Aug 2011 15:12:56 +1200, Amos Jeffries wrote: >> On Thu, 11 Aug 2011 11:09:38 +1200, Robert Collins wrote: >>> (But for clarity - I'm fine with what you proposed, I just wanted to >>> consider whether the standards would let us do it more directly, which >>> they -nearly- do AFAICT). >>> >>> -Rob >> >> Same. I don't mind this type of extension ...BUT... >> >> I think fixing bug 2112 (lack of If-None-Match support) and bug 2617 >> (wrong ETag validation handling) should be done first before any >> extensions are tried. That will allow you to see who much of a problem >> (or not) the potential failure cases actually are in practice. >> >> Amos > > Want-Digest: and Digest: validation mechanism from > http://tools.ietf.org/html/rfc3230 covers the remainder of the proposal. > So no custom extensions needed to meet all the requirements.
We did reuse a few ideas from that part of the larger Jeff Mogul's work I mentioned earlier, but I believe RFC 3230 Digest and Want-Digest headers differ from what is being discussed here: - Their digests are for instances while our digests are for entities. - Their headers are end-to-end while ours are hop-by-hop. - AFAICT, their Digest header is meant mostly for responses, while our If-None-Match or Have-Digest header is used in requests. Want-Digest or a similar support advertisement is wasteful in the common case, but is also useful to prevent sending If-None-Match or Have-Digest requests to servers that do not understand them. This is something we may want to add. Thank you, Alex.
