* lisp/gnus/*registry.el: Use slot names rather than initarg names
[emacs.git] / lisp / gnus / gnus-dup.el
blobb6686a30b85cc1e56fc4bd87227ad5aae5a59fca
1 ;;; gnus-dup.el --- suppression of duplicate articles in Gnus
3 ;; Copyright (C) 1996-2015 Free Software Foundation, Inc.
5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
6 ;; Keywords: news
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software: you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation, either version 3 of the License, or
13 ;; (at your option) any later version.
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
23 ;;; Commentary:
25 ;; This package tries to mark articles as read the second time the
26 ;; user reads a copy. This is useful if the server doesn't support
27 ;; Xref properly, or if the user reads the same group from several
28 ;; servers.
30 ;;; Code:
32 (eval-when-compile (require 'cl))
34 (require 'gnus)
35 (require 'gnus-art)
37 (defgroup gnus-duplicate nil
38 "Suppression of duplicate articles."
39 :group 'gnus)
41 (defcustom gnus-save-duplicate-list nil
42 "*If non-nil, save the duplicate list when shutting down Gnus.
43 If nil, duplicate suppression will only work on duplicates
44 seen in the same session."
45 :group 'gnus-duplicate
46 :type 'boolean)
48 (defcustom gnus-duplicate-list-length 10000
49 "*The number of Message-IDs to keep in the duplicate suppression list."
50 :group 'gnus-duplicate
51 :type 'integer)
53 (defcustom gnus-duplicate-file (nnheader-concat gnus-directory "suppression")
54 "*The name of the file to store the duplicate suppression list."
55 :group 'gnus-duplicate
56 :type 'file)
58 ;;; Internal variables
60 (defvar gnus-dup-list nil)
61 (defvar gnus-dup-hashtb nil)
63 (defvar gnus-dup-list-dirty nil)
65 ;;;
66 ;;; Starting and stopping
67 ;;;
69 (gnus-add-shutdown 'gnus-dup-close 'gnus)
71 (defun gnus-dup-close ()
72 "Possibly save the duplicate suppression list and shut down the subsystem."
73 (gnus-dup-save)
74 (setq gnus-dup-list nil
75 gnus-dup-hashtb nil
76 gnus-dup-list-dirty nil))
78 (defun gnus-dup-open ()
79 "Possibly read the duplicate suppression list and start the subsystem."
80 (if gnus-save-duplicate-list
81 (gnus-dup-read)
82 (setq gnus-dup-list nil))
83 (setq gnus-dup-hashtb (gnus-make-hashtable gnus-duplicate-list-length))
84 ;; Enter all Message-IDs into the hash table.
85 (let ((obarray gnus-dup-hashtb))
86 (mapc 'intern gnus-dup-list)))
88 (defun gnus-dup-read ()
89 "Read the duplicate suppression list."
90 (setq gnus-dup-list nil)
91 (when (file-exists-p gnus-duplicate-file)
92 (load gnus-duplicate-file t t t)))
94 (defun gnus-dup-save ()
95 "Save the duplicate suppression list."
96 (when (and gnus-save-duplicate-list
97 gnus-dup-list-dirty)
98 (with-temp-file gnus-duplicate-file
99 (gnus-prin1 `(setq gnus-dup-list ',gnus-dup-list))))
100 (setq gnus-dup-list-dirty nil))
103 ;;; Interface functions
106 (defun gnus-dup-enter-articles ()
107 "Enter articles from the current group for future duplicate suppression."
108 (unless gnus-dup-list
109 (gnus-dup-open))
110 (setq gnus-dup-list-dirty t) ; mark list for saving
111 (let (msgid)
112 ;; Enter the Message-IDs of all read articles into the list
113 ;; and hash table.
114 (dolist (datum gnus-newsgroup-data)
115 (when (and (not (gnus-data-pseudo-p datum))
116 (> (gnus-data-number datum) 0)
117 (not (memq (gnus-data-number datum) gnus-newsgroup-unreads))
118 (not (= (gnus-data-mark datum) gnus-canceled-mark))
119 (setq msgid (mail-header-id (gnus-data-header datum)))
120 (not (nnheader-fake-message-id-p msgid))
121 (not (intern-soft msgid gnus-dup-hashtb)))
122 (push msgid gnus-dup-list)
123 (intern msgid gnus-dup-hashtb))))
124 ;; Chop off excess Message-IDs from the list.
125 (let ((end (nthcdr gnus-duplicate-list-length gnus-dup-list)))
126 (when end
127 (mapc (lambda (id) (unintern id gnus-dup-hashtb)) (cdr end))
128 (setcdr end nil))))
130 (defun gnus-dup-suppress-articles ()
131 "Mark duplicate articles as read."
132 (unless gnus-dup-list
133 (gnus-dup-open))
134 (gnus-message 8 "Suppressing duplicates...")
135 (let ((auto (and gnus-newsgroup-auto-expire
136 (memq gnus-duplicate-mark gnus-auto-expirable-marks)))
137 number)
138 (dolist (header gnus-newsgroup-headers)
139 (when (and (intern-soft (mail-header-id header) gnus-dup-hashtb)
140 (gnus-summary-article-unread-p (mail-header-number header)))
141 (setq gnus-newsgroup-unreads
142 (delq (setq number (mail-header-number header))
143 gnus-newsgroup-unreads))
144 (if (not auto)
145 (push (cons number gnus-duplicate-mark) gnus-newsgroup-reads)
146 (push number gnus-newsgroup-expirable)
147 (push (cons number gnus-expirable-mark) gnus-newsgroup-reads)))))
148 (gnus-message 8 "Suppressing duplicates...done"))
150 (defun gnus-dup-unsuppress-article (article)
151 "Stop suppression of ARTICLE."
152 (let* ((header (gnus-data-header (gnus-data-find article)))
153 (id (when header (mail-header-id header))))
154 (when id
155 (setq gnus-dup-list-dirty t)
156 (setq gnus-dup-list (delete id gnus-dup-list))
157 (unintern id gnus-dup-hashtb))))
159 (provide 'gnus-dup)
161 ;;; gnus-dup.el ends here