1 ;;; gnus-sync.el --- synchronization facility for Gnus
4 ;;; Free Software Foundation, Inc.
6 ;; Author: Ted Zlatanov <tzz@lifelogs.com>
7 ;; Keywords: news synchronization nntp nnrss
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software: you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation, either version 3 of the License, or
14 ;; (at your option) any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
26 ;; This is the gnus-sync.el package.
28 ;; Put this in your startup file (~/.gnus.el for instance)
30 ;; (setq gnus-sync-backend `("/remote:/path.gpg") ; will use Tramp+EPA if loaded
31 ;; gnus-sync-global-vars `(gnus-newsrc-last-checked-date)
32 ;; gnus-sync-newsrc-groups `("nntp" "nnrss")
33 ;; gnus-sync-newsrc-vars `(read marks))
37 ;; - after gnus-sync-read, the message counts are wrong
41 (eval-when-compile (require 'cl))
44 (defgroup gnus-sync nil
45 "The Gnus synchronization facility."
49 (defcustom gnus-sync-newsrc-groups `("nntp" "nnrss")
50 "List of groups to be synchronized in the gnus-newsrc-alist.
51 The group names are matched, they don't have to be fully
52 qualified. Typically you would choose all of these. That's the
53 default because there is no active sync backend by default, so
54 this setting is harmless until the user chooses a sync backend."
56 :type '(repeat regexp))
58 (defcustom gnus-sync-newsrc-offsets '(2 3)
59 "List of per-group data to be synchronized."
61 :type '(set (const :tag "Read ranges" 2)
62 (const :tag "Marks" 3)))
64 (defcustom gnus-sync-global-vars nil
65 "List of global variables to be synchronized.
66 You may want to sync `gnus-newsrc-last-checked-date' but pretty
67 much any symbol is fair game. You could additionally sync
68 `gnus-newsrc-alist', `gnus-server-alist', `gnus-topic-topology',
69 and `gnus-topic-alist' to cover all the variables in
70 newsrc.eld (except for `gnus-format-specs' which should not be
71 synchronized, I believe). Also see `gnus-variable-list'."
73 :type '(repeat (choice (variable :tag "A known variable")
74 (symbol :tag "Any symbol"))))
76 (defcustom gnus-sync-backend nil
77 "The synchronization backend."
79 :type '(radio (const :format "None" nil)
80 (string :tag "Sync to a file")))
82 (defvar gnus-sync-newsrc-loader nil
83 "Carrier for newsrc data")
85 (defun gnus-sync-save ()
86 "Save the Gnus sync data to the backend."
88 (gnus-message 6 "Saving the Gnus sync data")
90 ((stringp gnus-sync-backend)
91 (gnus-message 7 "gnus-sync: saving to backend %s" gnus-sync-backend)
92 ;; populate gnus-sync-newsrc-loader from all but the first dummy
93 ;; entry in gnus-newsrc-alist whose group matches any of the
94 ;; gnus-sync-newsrc-groups
95 (let ((gnus-sync-newsrc-loader
96 (loop for entry in (cdr gnus-newsrc-alist)
97 when (gnus-grep-in-list
98 (car entry) ;the group name
99 gnus-sync-newsrc-groups)
100 collect (cons (car entry)
101 (mapcar (lambda (offset)
102 (cons offset (nth offset entry)))
103 gnus-sync-newsrc-offsets)))))
105 (with-temp-file gnus-sync-backend
107 (let ((coding-system-for-write gnus-ding-file-coding-system)
108 (standard-output (current-buffer)))
109 (princ (format ";; -*- mode:emacs-lisp; coding: %s; -*-\n"
110 gnus-ding-file-coding-system))
111 (princ ";; Gnus sync data v. 0.0.1\n")
112 (let* ((print-quoted t)
114 (print-escape-multibyte nil)
115 (print-escape-nonascii t)
119 (print-escape-newlines t)
120 (variables (cons 'gnus-sync-newsrc-loader
121 gnus-sync-global-vars))
124 (when (and (boundp (setq variable (pop variables)))
125 (symbol-value variable))
127 (princ (symbol-name variable))
129 (prin1 (symbol-value variable))
133 "gnus-sync: stored variables %s and %d groups in %s"
134 gnus-sync-global-vars
135 (length gnus-sync-newsrc-loader)
138 ;; Idea from Dan Christensen <jdc@chow.mat.jhu.edu>
139 ;; Save the .eld file with extra line breaks.
140 (gnus-message 8 "gnus-sync: adding whitespace to %s"
143 (goto-char (point-min))
144 (while (re-search-forward "^(\\|(\\\"" nil t)
145 (replace-match "\n\\&" t))
146 (goto-char (point-min))
147 (while (re-search-forward " $" nil t)
148 (replace-match "" t t))))))))
149 ;; the pass-through case: gnus-sync-backend is not a known choice
152 (defun gnus-sync-read ()
153 "Load the Gnus sync data from the backend."
155 (when gnus-sync-backend
156 (gnus-message 7 "gnus-sync: loading from backend %s" gnus-sync-backend)
157 (cond ((stringp gnus-sync-backend)
159 (if (or debug-on-error debug-on-quit)
160 (load gnus-sync-backend nil t)
162 (load gnus-sync-backend nil t)
164 (error "Error in %s: %s" gnus-sync-backend (cadr var)))))
166 (loop for node in gnus-sync-newsrc-loader
167 if (gnus-gethash (car node) gnus-newsrc-hashtb)
169 (dolist (node valid-nodes)
170 (loop for store in (cdr node)
171 do (setf (nth (car store)
172 (assoc (car node) gnus-newsrc-alist))
176 "gnus-sync: loaded %d groups (out of %d) from %s"
178 (length gnus-sync-newsrc-loader)
180 (setq gnus-sync-newsrc-loader nil)))
182 ;; make the hashtable again because the newsrc-alist may have been modified
183 (when gnus-sync-newsrc-offsets
184 (gnus-message 9 "gnus-sync: remaking the newsrc hashtable")
185 (gnus-make-hashtable-from-newsrc-alist))))
188 (defun gnus-sync-initialize ()
189 "Initialize the Gnus sync facility."
191 (gnus-message 5 "Initializing the sync facility")
192 (gnus-sync-install-hooks))
195 (defun gnus-sync-install-hooks ()
196 "Install the sync hooks."
198 (add-hook 'gnus-get-new-news-hook 'gnus-sync-read)
199 (add-hook 'gnus-save-newsrc-hook 'gnus-sync-save)
200 (add-hook 'gnus-read-newsrc-el-hook 'gnus-sync-read))
202 (defun gnus-sync-unload-hook ()
203 "Uninstall the sync hooks."
205 (remove-hook 'gnus-get-new-news-hook 'gnus-sync-read)
206 (remove-hook 'gnus-save-newsrc-hook 'gnus-sync-save)
207 (remove-hook 'gnus-read-newsrc-el-hook 'gnus-sync-read))
209 (add-hook 'gnus-sync-unload-hook 'gnus-sync-unload-hook)
211 ;; this is harmless by default, until the gnus-sync-backend is set
212 (gnus-sync-initialize)
216 ;;; gnus-sync.el ends here