Re: What is an "up to date" version?



> On 29 Oct 2017, at 08:19, Story H.J. <H.J.Story@soton.ac.uk> wrote:
> 
>> On 29 Oct 2017, at 03:11, Ed - 0x1b, Inc. <w3c@0x1b.com<mailto:w3c@0x1b.com>> wrote:
>> 
>> I would guess an up to date etag is typical for cache freshness.
>> https://en.wikipedia.org/wiki/HTTP_ETag
> 
> close. The Etag won't tell the local cache if it needs to update the version, it will
> just be useful when making a request to ask for one where intermediary caches
> can say, nothing has changed since you last looked.
> Look at
> https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.6

> and
> https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9

> 

Even better there is the Expires header:
https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.21


And all the text around it in section 14



> Henry
> 
> 
> On Sat, Oct 28, 2017 at 2:10 PM, Martynas Jusevičius
> <martynas@atomgraph.com<mailto:martynas@atomgraph.com>> wrote:
> Hi,
> 
> I'm implementing a cache for WebID graphs to improve performance. I was
> looking at WebID-TLS 4.1 Authentication sequence, which says:
> "If the WebID Verifier has an up to date version of the graph in its graph
> cache then it can return it."
> https://dvcs.w3.org/hg/WebID/raw-file/tip/spec/tls-respec.html#authentication-sequence

> 
> The phrase "up to date" is repeated multiple times later on, but not defined
> anywhere.
> 
> So what is it and who decides that -- the implementor? For how long am I
> supposed to safely cache the graphs?
> 
> 
> Martynas
> atomgraph.com
> 
> 

Received on Sunday, 29 October 2017 07:40:02 UTC