Sponsor etag/vary support for Squid 3.3

[Ed W <lists@xxxxxxxxxxxxxx>]

Hi, Alex,

I'm picking up an old thread from some time back.  I remain interested 
in getting support for etag into squid (and related revalidate support).

My main requirement is that I have two proxies on either side of a 
bandwidth limited link (with high cost).  I want the situation that when 
a client GETs some object, we can convert this to an IF-NONE-MATCH and 
trust the etag confirms that the object is unchanged.

Note, I am aware of the limitations of trusting etags. In my setup I 
will have control over the proxy on the high speed side of the 
connection and we can use various methods on that side to ensure that 
the etags are sane. The main goal is to minimise bandwidth across the 
intermediate (expensive) link.

Previously we discussed all kinds of complex ideas including 
implementing trailers, and custom headers with hash values.  On 
reflection I think everything required can be done using only etag 
revalidation (and some tweaking of etags, but squid needs know nothing 
about that...)


If anyone else is interested in such support then please shout. Alex, 
would you mind picking this up with me again with a view to sponsoring 
development?

Thanks

Ed W