root/trunk/lisp/gnus/gnus-move.el

;;; gnus-move.el --- commands for moving Gnus from one server to another

;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;;; Code:

(eval-when-compile (require 'cl))

(require 'gnus)
(require 'gnus-start)
(require 'gnus-int)
(require 'gnus-range)

;;;
;;; Moving by comparing Message-ID's.
;;;

;;;###autoload
(defun gnus-change-server (from-server to-server)
  "Move from FROM-SERVER to TO-SERVER.
Update the .newsrc.eld file to reflect the change of nntp server."
  (interactive
   (list gnus-select-method (gnus-read-method "Move to method: ")))

  ;; First start Gnus.
  (let ((gnus-activate-level 0)
        (mail-sources nil)
        (nnmail-spool-file nil))
    (gnus))

  (save-excursion
    ;; Go through all groups and translate.
    (let ((newsrc gnus-newsrc-alist)
          (nntp-nov-gap nil)
          info)
      (while (setq info (pop newsrc))
        (when (gnus-group-native-p (gnus-info-group info))
          (gnus-move-group-to-server info from-server to-server))))))

(defun gnus-move-group-to-server (info from-server to-server)
  "Move group INFO from FROM-SERVER to TO-SERVER."
  (let ((group (gnus-info-group info))
        to-active hashtb type mark marks
        to-article to-reads to-marks article
        act-articles)
    (gnus-message 7 "Translating %s..." group)
    (when (gnus-request-group group nil to-server)
      (setq to-active (gnus-parse-active)
            hashtb (gnus-make-hashtable 1024)
            act-articles (gnus-uncompress-range to-active))
      ;; Fetch the headers from the `to-server'.
      (when (and to-active
                 act-articles
                 (setq type (gnus-retrieve-headers
                             act-articles
                             group to-server)))
        ;; Convert HEAD headers.  I don't care.
        (when (eq type 'headers)
          (nnvirtual-convert-headers))
        ;; Create a mapping from Message-ID to article number.
        (set-buffer nntp-server-buffer)
        (goto-char (point-min))
        (while (looking-at
                "^[0-9]+\t[^\t]*\t[^\t]*\t[^\t]*\t\\([^\t]*\\)\t")
          (gnus-sethash
           (buffer-substring (match-beginning 1) (match-end 1))
           (read (current-buffer))
           hashtb)
          (forward-line 1))
        ;; Then we read the headers from the `from-server'.
        (when (and (gnus-request-group group nil from-server)
                   (gnus-active group)
                   (gnus-uncompress-range
                    (gnus-active group))
                   (setq type (gnus-retrieve-headers
                               (gnus-uncompress-range
                                (gnus-active group))
                               group from-server)))
          ;; Make it easier to map marks.
          (let ((mark-lists (gnus-info-marks info))
                ms type m)
            (while mark-lists
              (setq type (caar mark-lists)
                    ms (gnus-uncompress-range (cdr (pop mark-lists))))
              (while ms
                (if (setq m (assq (car ms) marks))
                    (setcdr m (cons type (cdr m)))
                  (push (list (car ms) type) marks))
                (pop ms))))
          ;; Convert.
          (when (eq type 'headers)
            (nnvirtual-convert-headers))
          ;; Go through the headers and map away.
          (set-buffer nntp-server-buffer)
          (goto-char (point-min))
          (while (looking-at
                  "^[0-9]+\t[^\t]*\t[^\t]*\t[^\t]*\t\\([^\t]*\\)\t")
            (when (setq to-article
                        (gnus-gethash
                         (buffer-substring (match-beginning 1) (match-end 1))
                         hashtb))
              ;; Add this article to the list of read articles.
              (push to-article to-reads)
              ;; See if there are any marks and then add them.
              (when (setq mark (assq (read (current-buffer)) marks))
                (setq marks (delq mark marks))
                (setcar mark to-article)
                (push mark to-marks))
              (forward-line 1)))
          ;; Now we know what the read articles are and what the
          ;; article marks are.  We transform the information
          ;; into the Gnus info format.
          (setq to-reads
                (gnus-range-add
                 (gnus-compress-sequence
                  (and (setq to-reads (delq nil to-reads))
                       (sort to-reads '<))
                  t)
                 (cons 1 (1- (car to-active)))))
          (gnus-info-set-read info to-reads)
          ;; Do the marks.  I'm sure y'all understand what's
          ;; going on down below, so I won't bother with any
          ;; further comments.  <duck>
          (let ((mlists gnus-article-mark-lists)
                lists ms a)
            (while mlists
              (push (list (cdr (pop mlists))) lists))
            (while (setq ms (pop marks))
              (setq article (pop ms))
              (while ms
                (setcdr (setq a (assq (pop ms) lists))
                        (cons article (cdr a)))))
            (setq a lists)
            (while a
              (setcdr (car a) (gnus-compress-sequence
                               (and (cdar a) (sort (cdar a) '<))))
              (pop a))
            (gnus-info-set-marks info lists t)))))
    (gnus-message 7 "Translating %s...done" group)))

(defun gnus-group-move-group-to-server (info from-server to-server)
  "Move the group on the current line from FROM-SERVER to TO-SERVER."
  (interactive
   (let ((info (gnus-get-info (gnus-group-group-name))))
     (list info (gnus-find-method-for-group (gnus-info-group info))
           (gnus-read-method (format "Move group %s to method: "
                                     (gnus-info-group info))))))
  (save-excursion
    (gnus-move-group-to-server info from-server to-server)
    ;; We have to update the group info to point use the right server.
    (gnus-info-set-method info to-server t)
    ;; We also have to change the name of the group and stuff.
    (let* ((group (gnus-info-group info))
           (new-name (gnus-group-prefixed-name
                      (gnus-group-real-name group) to-server)))
      (gnus-info-set-group info new-name)
      (gnus-sethash new-name (gnus-gethash group gnus-newsrc-hashtb)
                    gnus-newsrc-hashtb)
      (gnus-sethash group nil gnus-newsrc-hashtb))))

(provide 'gnus-move)

;;; arch-tag: 503742b8-7d66-4d79-bb31-4a698070707b
;;; gnus-move.el ends here