[Voiceglue] On audio caching and HTTP cookies

[Archie Cobbs]

On Mon, Feb 16, 2009 at 2:08 PM, Doug Campbell <voiceglue at campbellcastle.com
> wrote:
>
> The problem comes in determining which audio fetches are
> static and which are dynamic.
>
> While I would like to be able to determine static versus
> dynamic audio fetches by examining the server HTTP headers
> Expires: <now>, Cache-Control: no-cache, Cache-Control:
> private, and Cache-Control: s-maxage=0, I cannot wait for the
> server response as by then it is too late to have sent cookies.
>
> So, I propose determining static audio fetches as those having
> a VXML maxage attribute (or audiomaxage property if not defined)
> not equal to 0.  Conversely, dynamic audio fetches have maxage
> set to 0.  This gives the VXML script author full control over
> whether to use the shared cache for any particular audio resource.


I'm not an expert on this stuff, but surely there exists a "correct" answer
that is in accordance with the HTTP protocol.

For example, what does Google send with their logo image when you go to
their search page?

Also, I don't understand the problem described in the second paragraph
above. I.e., you seem to believe that the Expires and Cache-Control headers
are limited in "scope" to requests with the same cookie. But I think this is
not true. The cookie mechanism is independent from the cache control stuff.
So you should be able to just send the cookies always, and then do whatever
the headers tell you do about caching when you get the response. If you
request the same URL with different cookies, and the result was previously
(correctly) cached, then you should be able to just use it. If that's wrong
then it's not your fault, it's the HTTP server's.

But I could be wrong... :-)

-Archie

-- 
Archie L. Cobbs
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