From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/37441 Path: main.gmane.org!not-for-mail From: Simon Josefsson Newsgroups: gmane.emacs.gnus.general Subject: Re: Backend writing Date: Sat, 04 Aug 2001 02:11:26 +0200 Message-ID: References: NNTP-Posting-Host: coloc-standby.netfonds.no Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Trace: main.gmane.org 1035172856 13889 80.91.224.250 (21 Oct 2002 04:00:56 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Mon, 21 Oct 2002 04:00:56 +0000 (UTC) Return-Path: Return-Path: Original-Received: (qmail 464 invoked from network); 4 Aug 2001 00:10:07 -0000 Original-Received: from dolk.extundo.com (195.42.214.242) by gnus.org with SMTP; 4 Aug 2001 00:10:07 -0000 Original-Received: from barbar.josefsson.org (slipsten.extundo.com [195.42.214.241]) (authenticated) by dolk.extundo.com (8.11.3/8.11.3) with ESMTP id f740AGw00803 for ; Sat, 4 Aug 2001 02:10:16 +0200 Original-To: ding@gnus.org In-Reply-To: (prj@po.cwru.edu's message of "Fri, 03 Aug 2001 19:46:38 -0400") Mail-Copies-To: nobody User-Agent: Gnus/5.090004 (Oort Gnus v0.04) Emacs/21.0.104 Original-Lines: 39 Xref: main.gmane.org gmane.emacs.gnus.general:37441 X-Report-Spam: http://spam.gmane.org/gmane.emacs.gnus.general:37441 prj@po.cwru.edu (Paul Jarc) writes: > Simon Josefsson writes: >> Kai.Grossjohann@CS.Uni-Dortmund.DE (Kai Großjohann) writes: >>> But haven't you just changed nnimap to ignore article renumberings? I >>> suppose you wouldn't do that unless it's safe? >> >> I don't know if it's safe, that's what Oort is for. > > FWIW, nnmaildir has been renumbering articles each time you open the > server since 2001-04-11. No problems yet. But you seem to be dealing > with something that changes more frequently than that, right? Depends, some IMAP server seem to change the UIDVALIDITY value more or less at will (UIDVALIDITY indicate that a renumbering might have taken place). Most don't. And those that do sometimes doesn't actually renumber anything, so it just "works" anyway. The problem is when a uidvalidity change is actually due to a real renumbering, and even more problem arise if the renumbering re-use article numbers. This kind of IMAP server design is rare though, so in practice I don't think it's a big problem. I think nnmaildir is different though, don't you hide the renumbering from Gnus (by translating back and forth between old and new numbering)? Nnimap doesn't, it simply present the servers article numbers to Gnus and hopes for the best. (And assuming uidvalidity doesn't change, the IMAP design guarantee that Gnus will be happy. Problem is when uidvalidity change...). >> Basicly, nnimap makes sure the old NOV cache isn't used when a >> uidvalidity has changed. [...] It gets sort of ugly if a backend >> has to update internal things of Gnus's cache and agent. > > Does this mean nnimap is stepping outside the backend interface? Not this time, nnimap doesn't mess with the cache or agent. So an article cached by Gnus might become invalid if a renumbering has happened. It would be nice if nnimap could tell the cache/agent to invalidate everything it knows about stored articles.