[Orgmode] Re: Fixing slowness of following Gnus links to IMAP articles

[Tassilo Horn]

David Maus <address@hidden> writes:

Hi David,

> Finally I got a novcache:

Congratulations! ;-)

> ,----[ gnus.el ]
> | ;;; Experimental Gnus setup
> |
> | (setq gnus-select-method '(nntp "news.gmane.org"))
> | (setq gnus-secondary-select-methods
> |       '((nnimap "localhost"
> |             (nnimap-address "localhost")
> |             (nnimap-server-port 993)
> |             (nnimap-stream ssl))))
> |
> | (setq nnimap-nov-is-evil nil)
> | (setq gnus-cache-enter-articles '(ticked dormant unread read))
> |
> | (setq org-gnus-nnimap-query-article-no-from-file t)
> `----
>
> Now the strange thing is that the novcache file in ~/News/overview is
> 100% identical to .overview in ~/News/agent

Two are better than one!  (I have no idea why.)

> ,----
> | address@hidden ~/News % md5sum 
> overview/nnimap/localhost/INBOX/1280089306/novcache 
> agent/nnimap/localhost/INBOX/.overview
> | b4a78e25a064f0c260f76080a00991cd  
> overview/nnimap/localhost/INBOX/1280089306/novcache
> | b4a78e25a064f0c260f76080a00991cd  agent/nnimap/localhost/INBOX/.overview
> | address@hidden ~/News %
> `----
>
> Anyway: `nnimap-retrieve-headers-from-file' does not work as expected.
> First, it requires the group parameter without backend and server
> prefix (e.g. "INBOX" instead of "nnimap+localhost:INBOX".

I've expected that.

> Second it would return a cons (min-UID . max-UID).  That wouldn't help
> us, would it?

What an appropriately named function that is. ;-) No, that wouldn't
help.  But its code could be stolen to write and own function to insert
the right NOV file in a temp buffer, to search for the message-id.
Something like that:

--8<---------------cut here---------------start------------->8---
(defun org-gnus-nnimap-get-article-number (group server message-id)
  (with-current-buffer nntp-server-buffer
    (let ((nov (nnimap-group-overview-filename group server)))
      (when (file-exists-p nov)
        (mm-insert-file-contents nov)
        (set-buffer-modified-p nil)
        (when (search-forward message-id nil t)
          (goto-char (line-beginning-position))
          (read (current-buffer)))))))
--8<---------------cut here---------------end--------------->8---

That function is totally untested, but might do what it should.

> Third and amazingly my novcache seems to be corrupt right after
> creation: `nnimap-retrieve-headers-from-file' does not get the maximum
> UID but reads "INBOX" (?!) -- A string that looks kind of a header
> information for nov -- and not "18753" what is the highest UID in the
> mailbox.
>
> Last line of the cache:
> (it's a local copy of wanderlust general newsgroup accessed via IMAP)
>
> ,----
> | 18753       Re: checking imap folder unplugged      Yoichi NAKAYAMA 
> <address@hidden>        Sun, 13 Oct 2002 10:19:13 +0900 <address@hidden>      
>   <address@hidden>        4424    13      Xref: t41.ictsoc.de INBOX:18753 
> Newsgroups: gmane.mail.wanderlust.general.japanese
> `----

Really strange.  Maybe the corruption comes from replacing TABs by
spaces using some home-brewn auto-replace-all-tabs-with-spaces function?

Bye,
Tassilo