[Zope-CMF] Re: CachingPolicyManager improvements

[Florent Guillaume]

Hm I fucked the Cc field, resending.

Florent Guillaume wrote:
> Geoff Davis wrote:
> 
>> 3) FSPageTemplates have the option to return a status 304 + no content
>> when a conditional GET is sent.  This is a potential significant win for
>> sites.
>> How it works: When a client has an expired page in its local cache, it
>> sends a conditional GET to the server.  Basically that means that there
>> will be an If-Modified-Since header with the timestamp of the local 
>> cached
>> page and, if the cached page was originally sent with an ETag, an
>> If-None-Match header with the ETag of the cached page (actually a list of
>> ETags of cached pages).
>>
>> If an FSPageTemplate is associated with a Caching Policy and that Caching
>> Policy has 304s explicitly enabled, a series of checks take place.  If
>> there is an If-Modified-Since header, the server checks the modification
>> time associated with the template via the Caching Policy.  If there is an
>> If-None-Match header and the Caching Policy defines an ETag function, the
>> ETag is checked.  If all the checks pass, the server returns a 304 status
>> and stops without rendering the page.  The server does less computation,
>> and less data goes over the wire, so it's a double win.
> 
> 
> If I'm not mistaken, this will only be useful for ZPTs that provide 
> unchanged content over time ? Like css or scripts or invariant 
> resources, i.e. not useful for the usual case of views ?
> 
> Florent
> 


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Florent Guillaume, Nuxeo (Paris, France)   CTO, Director of R&D
+33 1 40 33 71 59   http://nuxeo.com   fg at nuxeo.com