Re: Gnus: caching message headers?

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Gregory Heytings via Users list for the GNU Emacs text editor
<help-gnu-emacs@gnu.org> writes:

> Hi list,
>
> I'm trying to configure Gnus to access my email through IMAP.
>
> I'm too accustomed to traditional MUAs to switch to the "Gnus way" in
> one step, so I have:
>
> (setq gnus-permanently-visible-groups ".*")
> (setq gnus-parameters
>    '((".*"
>       (gnus-show-threads nil)
>       (gnus-use-scoring nil)
>       (gnus-article-sort-functions '(gnus-article-sort-by-number))
>       (display . all))))
>
> I would like to have, in the *Summary*, a complete list of the emails
> contained in a folder when I hit RET on its label.  Each time I do
> this however, Gnus asks me how many articles I want to retrieve, and
> issues a "UID FETCH 1:N (UID RFC822.SIZE BODYSTRUCTURE
> BODY.PEEK[HEADER.FIELDS (...)])" IMAP command, which can take quite
> some time to complete when N is large.
>
> Is there a way to convince Gnus to cache the result of that command
> (without caching all emails), and to issue a command only for the new
> UIDs?  Caching the result of that command should not eat too much disk
> space.

No, not at the moment. You can avoid the prompt by customizing the value
of `gnus-large-newsgroup', but it's still going to retrieve all the
headers for the group.

There's currently no way around this, as Gnus only lets you have one
active Summary buffer at a time, which means all the old data is dumped
every time you switch groups. In the back of my head I have some ideas
for removing this restriction, but it will take a long time to get
there.

Eric