- From: Larry Masinter <masinter@parc.xerox.com>
- Date: Tue, 12 Mar 1996 00:30:45 PST
- To: paulle@microsoft.com
- Cc: fielding@avron.ICS.UCI.EDU, http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
> Good point. The one thing that I think still differs is that lost is > the ability for the cache to know that several things with the same URI > are variants of one another, as opposed to just a single instance that > has changed over time. With IF-ID/Unless-ID/Content-ID: > Client Server > GET /foo.txt HTTP/1.1 > HTTP/1.0 200 OK > Content-ID: "asdasfa" > GET /foo.txt HTTP/1.1 > HTTP/1.0 200 OK > Content-ID: "xxxxx" > How does the cache know if the two "foo.txt" are variants of one > another, or if the one-and-only "foo.txt" has changed? The 'last-modified' of a negotiable resource should be the maximum of the last-modified of all presentations. If the two responses have the same last-modified, the two contents are variants (and need a Vary header); if the second has a different last-modified, then it marks all the other variants than the one being served as stale.
Received on Tuesday, 12 March 1996 00:34:49 UTC