Re: Packing nnml folders...

[Lloyd Zusman <ljz@asfast.com>]

prj@po.cwru.edu (Paul Jarc) writes:

> Lloyd Zusman <ljz@asfast.com> writes:
>> As soon as I figure out how to mass-copy the customization settings,
>> I'll write the function that does this "repacking from 1" operation
>> for nnml groups.
> 
> I don't think it would have to be specific to nnml.  If you were going
> to involve a particular backend, then you might as well make the
> backend store marks.  Then the renumbering could be done
> automatically, without requiring user intervention.

I agree that this would be the ideal way to handle group renumbering.

However, I'm not too familiar with backend processing, and so for the
moment, I don't feel confident enough to tackle that task.  Maybe one
of these days ... <sigh>

But for the time being, I've hacked out a function that will renumber
and repack an nnml group.  You can see it below.

WARNING!!! ... this is experimental.  I've tested it within my own
environment and it seems to work, but I wouldn't rely on it without a
lot more testing.  Be sure to BACK UP EVERYTHING before playing with
it.

And even if it seems to work, I strongly recommend to not yet make it
part of Gnus until a lot more error checking is inserted into the
code.  Also, I think that it can be rewritten to be more efficient.
Please remember that THIS IS STILL EXPERIMENTAL.

Nevertheless, it works for me, and if nothing else, it's a proof of
concept.  What do you folks think of it?

;; Helper function: return a unique, temporary group name
;; that's based on a specified nnml group name.
(defun create-temp-nnml-group-name (group)
  (let ((temp-name-pattern (concat group "-temp-%d"))
	(n 0)
	temp-name)
    ;; Uniqueness test:  1. make sure that no group exists
    ;;                      with the same name
    ;;                   2. make sure that there's no
    ;;                      nnml directory for a group
    ;;                      of this name (such a directory
    ;;                      might still exist if a group
    ;;                      with the specified name was
    ;;                      previously deleted)
    (while (or (gnus-gethash
		(setq temp-name (format temp-name-pattern n))
		gnus-newsrc-hashtb)
	       (file-directory-p
		(nnmail-group-pathname
		 (gnus-group-real-name temp-name) nnml-directory)))
      (setq n (1+ n)))
    temp-name))

;; Repack and renumber an nnml group.  I only allow this to work
;; if it's invoked from within the Group buffer.
(defun repack-and-renumber-nnml-group (group)
  (interactive (list
		(gnus-completing-read
		 (gnus-group-group-name)
		 "Group:" gnus-active-hashtb
		 nil 'require-match)))
  (unless (eq (current-buffer) (get-buffer gnus-group-buffer))
    (error "Must be invoked from within the %s buffer"
	   gnus-group-buffer))
  ;; Get the first temporary group name.
  (let ((temp-group-1 (create-temp-nnml-group-name group))
	temp-group-2)
    ;; Enter the group, with all articles visible.
    (gnus-group-read-group t t group)
    ;; Mark every article
    (gnus-uu-mark-all)
    ;; Copy the articles to the temporary group.
    ;; NOTE: if you're confident that all of this will
    ;;       work, you can change the following
    ;;       function to `gnus-summary-move-article'.
    (gnus-summary-copy-article nil temp-group-1)
    ;; Make sure we're back in the Group buffer
    (gnus-summary-exit)
    ;; Make sure that tne newly created temporary
    ;; group is of the same level as the original;
    ;; also positions the new group right before
    ;; the original.
    (gnus-group-change-level temp-group-1
			     (gnus-group-level group)
			     (gnus-group-level temp-group-1)
			     group)
    ;; Make sure that the new group has the same
    ;; customization parameters as the original.
    (gnus-group-set-info 
     (gnus-info-params (gnus-get-info group))
     temp-group-1
     'params)
    ;; We need to get the next temporary group name
    ;; now, *after* the first temporary group has
    ;; been created.
    (setq temp-group-2 (create-temp-nnml-group-name group))
    ;; Rename everything.  For some reason, it's
    ;; necessary to list all the groups before
    ;; renaming and deleting.
    (gnus-group-list-groups gnus-level-unsubscribed t)
    (gnus-group-rename-group group temp-group-2)
    (gnus-group-list-groups gnus-level-unsubscribed t)
    (gnus-group-rename-group temp-group-1 group)
    ;; Delete the original group, which has now been
    ;; renamed.  You'll be prompted for this.  If
    ;; you're really brave, add a fourth parameter
    ;; `t' to the following function invocation
    ;; to avoid the prompt.
    (gnus-group-list-groups gnus-level-unsubscribed t)
    (gnus-group-delete-group temp-group-2 t)))



-- 
 Lloyd Zusman
 ljz@asfast.com