Re: Concerning marks and the back end.

[Lloyd Zusman <ljz@asfast.com>]

Lloyd Zusman <ljz@asfast.com> writes:

> Simon Josefsson <jas@extundo.com> writes:
>>
>> [ ... ]
>>
>> You can set the display parameter to an array of predicates, e.g.:
>>
>> [or unread (and no-unreads my-article-old-p)]
>>
>>      (defun my-article-old-p ()
>>        "Say whether an article is old."
>>        (< (time-to-days (date-to-time (mail-header-date gnus-headers)))
>>           (- (time-to-days (current-time)) gnus-agent-expire-days)))
>>
>> implementing the no-unreads function is left as an exercise. :-)
>>
>> But this might not work either, as I think display predicates was
>> implemented as limiting, so you will fetch all article headers anyway.
>
> Hmmm ... well, I could always cheat and use `defadvice' to wrap the
> function which enters the group; [ ... ]
>
> Sounds easy, anyway. :)

... and indeed it turned out to be straightforward.  The defadvice'd
function is below.  Yes, I know it's an ugly hack, and I'm still hoping
for a better way to do this.  But at least this works in the mean time.


>> But I still wonder why entering the group is slow for you.  I have
>> 15,000 messages in my ding mailing list mailbox, which is stored on a
>> IMAP server, and entering it and viewing the unread and ticked
>> articles takes no time.  When I get several hundred thousand articles
>> it becomes a little slow though (long coffe break).
>
> Well, I still will do the profiling that you suggested earlier.

... and I'll do this profiling soon.

Here's the function.  I could have used fewer variable definition steps
in the 'let' clause, but I broke it into more pieces for ease of
debugging during development.


 (defvar ljz-group-default-display-count 256
   "*Default count of articles to display when entering a group, if there
 are no unread, dormant, or ticked articles, and if there is no prefix
 argument.")

 (defadvice gnus-group-read-group (around gnus-group-read-group freeze)
   (interactive "P")
   (let* ((the-group (or group (gnus-group-group-name)))
	  (the-unread-count (gnus-group-unread the-group))
	  (the-marks (gnus-info-marks (gnus-get-info the-group)))
	  (the-dormant (cdr (assq 'dormant the-marks)))
	  (the-ticked (cdr (assq 'tick the-marks)))
	  (the-count
	   (+ the-unread-count (length the-dormant) (length the-ticked)))
	  (the-parameter (if all all (if (> the-count 0)
					 nil
				       ljz-group-default-display-count))))
     (ad-set-arg 0 the-parameter)
     ad-do-it))


-- 
 Lloyd Zusman
 ljz@asfast.com