RE: Demographics
Shel Kaphan (sjk@amazon.com)
Wed, 10 Jul 1996 12:19:03 -0700
Paul Leach writes:
...
> If fact, "Referer" makes it very hard for a cache to be semantically
> transparent: if a cache was trying to be semantically transparent, the
> presence of "Referer" on a GET request should cause a cache to do a
> conditional GET on the Request-URI. The only way to avoid this would be
> to remember each different value of Referer: had been seen and to report
> hit counts on each of them (somehow). Not only is this more complex than
> using cached 302s, it also would result in exactly as many remembered
> Referers as cached 302s in your proposal.
> >
Not that I'm recommending this per se, but if a server cared about
this, it could use the Vary header to indicate the result
varies on the Referer request-header, causing any caches to treat the
results independently.
Of course this would mean a lot more bookkeeping entries in caches, but
implementation-wise, if caches could have unique entries for resources that
were logically different but physically identical (using a digest hash
or something), this wouldn't be that much uglier than some
special case method of keeping track specifically by Referer.
--Shel