See programmers guide for an overview of the meta header tlv format, and the source for the fine details.. Regards Henrik mån 2006-03-27 klockan 10:31 -0500 skrev lawrence wang: > thanks for the clarification. looks like i have some hacking to do. > so, are these squid object headers documented, like at what offset i > should look to see if an object is a variant, or should i just dive > into the code? > > On 3/18/06, Henrik Nordstrom <henrik@xxxxxxxxxxxxxxxxxxx> wrote: > > lör 2006-03-18 klockan 08:41 -0500 skrev lawrence wang: > > > I see. But maybe I've phrased this wrong... It seems like when the > > > purge tool runs, it does find all the different variants for a given > > > URL and runs requests against each of them; of course the variants > > > which require specific headers return 404's when those are not found > > > in the request. Perhaps there's a way to relax this check without > > > breaking anything else? > > > > The PURGE tool must send the correct headers, or Squid won't know what > > to do. It's not a check, it's how things work. Squid-2.5 does not know > > what variants there is for a given URL, no more than it knows what URLs > > there is in the cache. All it knows to do is "OK, I now have these > > request headers and URL given to me from the client, is there a matching > > object". Without the headers it can not find or know the variant. > > Without the headers all Squid-2.5 find is that the object varies, but > > have no means of finding the variants. Note of warning: If you PURGE > > without the variant headers then Squid-2.5 forgets that the object > > varies and the remaining cached variants of the object can not be > > reached until Squid has again learned that the object varies by seeing a > > Vary header response from the server. This means that if you purge > > without the headers then there is no longer any way to purge the > > variants without first making a request (which will be a cache miss) for > > the URL. > > > > The PURGE tool could be modified to do this I suppose. Only needs to be > > taught the vary algorithm used by 2.5 and decode this into suitable > > request headers as part of the purge request sent to Squid. The required > > information for reconstructing the required headers is found in a meta > > TLV header of the object and is read by the purge tool. Only that it > > does not know the meaning of this information and consequently does not > > make use of it today. > > > > > > Regards > > Henrik > > > > > > -----BEGIN PGP SIGNATURE----- > > Version: GnuPG v1.4.2.2 (GNU/Linux) > > > > iD8DBQBEHCTK516QwDnMM9sRAvEUAJ0e/Qty3lLQXcoDUkumUv91cq2o+gCeLJLZ > > QyDpTTVIcvDI9qNs7D++Tq4= > > =jdRd > > -----END PGP SIGNATURE----- > > > > > >
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