Re: request-group-articles for nnimap

[David Engster <deng@randomsample.de>]

Ted Zlatanov writes:
> On Thu, 02 Sep 2010 16:39:11 +0200 David Engster <deng@randomsample.de> wrote: 
>
> DE> Yes, exactly. The nnimap-request-group-articles I posted simply returns
> DE> the list of available article numbers in that group (which could be
> DE> further compressed into the above range notation). Requesting the range
> DE> of articles can take a second for very large groups, so some kind of
> DE> caching should be done.
>
> Let the backend decide if caching is possible since it has the best
> knowledge of when the data is old.  It also knows best where to cache
> (on the server, in memory, on disk, etc.)  The caching policy can be set
> globally, but the rest should be on the backend IMO. 

Yes, it's probably easier when the backend does it. But we can worry
about that later. :-)

> DE> Anyway, this would be an optional back end function, and Gnus can query
> DE> the back end for availability and use it (if the user wants it). I for
> DE> example don't have much problems with the article count, but I don't
> DE> delete much and use Dovecot. But there are IMAP servers out there
> DE> (Zimbra...) which use absolutely insane values for article numbers;
> DE> maybe it's using those for Mersenne prime searching or something.
>
> So there's two pieces: the general facility and support for it in
> nnimap.  Let's get the nnimap piece done first and verify it works since
> we're close.  Can you modify your function to do compressed ranges?

It's a simple matter of calling gnus-compress-sequence.

>  Do you know of any alternate implementations or patches (I haven't
> kept track)?

As I wrote, Vitaly already had patches, also for the general backend,
but he extended the active information, without the usage of a new API
function. I think his patches can still be seen here:

http://repo.or.cz/w/more-gnus.git

My last test of those patches still showed some problems (see
http://thread.gmane.org/gmane.emacs.gnus.general/67238/focus=67407), but
they already show which parts of Gnus are affected.

We should first decide if we should build upon Vitaly's work with the
extended active, or if we use 'nnchoke-request-group-articles'. I have
difficulties following Lars' programming spree; maybe he has already
committed something which has decided this. ;-)

-David