- From: Lou Montulli <montulli@mozilla.com>
- Date: Mon, 13 Nov 1995 17:32:56 -0800
- To: Larry Masinter <masinter@parc.xerox.com>
- Cc: ietf-lists@proper.com, http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
Larry Masinter wrote:
>
> Wait wait, I keep on saying "if-not-modified-since" and you keep on
> replying "if-modified-since".
>
> Normally, GET with caching uses 'if-modified-since', i.e., give me the
> data if it's newer than/different from what I already have.
>
> However, GET of a byte range need the converse. It's "give me this
> byte range of this object, UNLESS the object is newer than/different
> from what I already have".
>
> The sense is different. HTTP doesn't have a "if-not-modified-since",
> and would need it if you want byte ranges to actually work with data
> that might change.
I agree with you. I think that "if-not-modified-since" would
be a great addition and would work well for byte-ranges.
It should be tied into the header some how though.
Maybe we should make "if-not-modified-since" an optional
attribute to the request-range header.
Therefore a byte range request would look like:
GET /byterange-capable-document HTTP/1.0
Request-Range: bytes=500-999; if-not-modified-since="DATE"
We should also be able to send size checksums, so we
could add 'if-size-equal="LENGTH"' as well.
:lou
--
Lou Montulli http://www.netscape.com/people/montulli/
Netscape Communications Corp.
Received on Monday, 13 November 1995 17:39:49 UTC