1 ;;; gnus-bcklg.el --- backlog functions for Gnus
3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
4 ;; 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
6 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
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/>.
28 (eval-when-compile (require 'cl))
33 ;;; Buffering of read articles.
36 (defvar gnus-backlog-buffer " *Gnus Backlog*")
37 (defvar gnus-backlog-articles nil)
38 (defvar gnus-backlog-hashtb nil)
40 (defun gnus-backlog-buffer ()
41 "Return the backlog buffer."
42 (or (get-buffer gnus-backlog-buffer)
43 (with-current-buffer (gnus-get-buffer-create gnus-backlog-buffer)
45 (setq buffer-read-only t)
46 (get-buffer gnus-backlog-buffer))))
48 (defun gnus-backlog-setup ()
49 "Initialize backlog variables."
50 (unless gnus-backlog-hashtb
51 (setq gnus-backlog-hashtb (gnus-make-hashtable 1024))))
53 (gnus-add-shutdown 'gnus-backlog-shutdown 'gnus)
55 (defun gnus-backlog-shutdown ()
56 "Clear all backlog variables and buffers."
58 (when (get-buffer gnus-backlog-buffer)
59 (gnus-kill-buffer gnus-backlog-buffer))
60 (setq gnus-backlog-hashtb nil
61 gnus-backlog-articles nil))
63 (defun gnus-backlog-enter-article (group number buffer)
64 (when (and (numberp number)
65 (not (string-match "^nnvirtual" group)))
67 (let ((ident (intern (concat group ":" (int-to-string number))
70 (if (memq ident gnus-backlog-articles)
71 () ; It's already kept.
72 ;; Remove the oldest article, if necessary.
73 (and (numberp gnus-keep-backlog)
74 (>= (length gnus-backlog-articles) gnus-keep-backlog)
75 (gnus-backlog-remove-oldest-article))
76 (push ident gnus-backlog-articles)
77 ;; Insert the new article.
78 (with-current-buffer (gnus-backlog-buffer)
79 (let (buffer-read-only)
80 (goto-char (point-max))
84 (insert-buffer-substring buffer)
85 ;; Tag the beginning of the article with the ident.
87 (gnus-put-text-property b (1+ b) 'gnus-backlog ident)
88 (gnus-error 3 "Article %d is blank" number))))))))
90 (defun gnus-backlog-remove-oldest-article ()
91 (with-current-buffer (gnus-backlog-buffer)
92 (goto-char (point-min))
93 (if (zerop (buffer-size))
94 () ; The buffer is empty.
95 (let ((ident (get-text-property (point) 'gnus-backlog))
97 ;; Remove the ident from the list of articles.
99 (setq gnus-backlog-articles (delq ident gnus-backlog-articles)))
100 ;; Delete the article itself.
102 (point) (next-single-property-change
103 (1+ (point)) 'gnus-backlog nil (point-max)))))))
105 (defun gnus-backlog-remove-article (group number)
106 "Remove article NUMBER in GROUP from the backlog."
107 (when (numberp number)
109 (let ((ident (intern (concat group ":" (int-to-string number))
110 gnus-backlog-hashtb))
112 (when (memq ident gnus-backlog-articles)
113 ;; It was in the backlog.
114 (with-current-buffer (gnus-backlog-buffer)
115 (let (buffer-read-only)
116 (when (setq beg (text-property-any
117 (point-min) (point-max) 'gnus-backlog
119 ;; Find the end (i. e., the beginning of the next article).
121 (next-single-property-change
122 (1+ beg) 'gnus-backlog (current-buffer) (point-max)))
123 (delete-region beg end)
126 (setq gnus-backlog-articles (delq ident gnus-backlog-articles)))))))
128 (defun gnus-backlog-request-article (group number &optional buffer)
129 (when (and (numberp number)
130 (not (string-match "^nnvirtual" group)))
132 (let ((ident (intern (concat group ":" (int-to-string number))
133 gnus-backlog-hashtb))
135 (when (memq ident gnus-backlog-articles)
136 ;; It was in the backlog.
137 (with-current-buffer (gnus-backlog-buffer)
138 (if (not (setq beg (text-property-any
139 (point-min) (point-max) 'gnus-backlog
141 ;; It wasn't in the backlog after all.
143 (setq gnus-backlog-articles (delq ident gnus-backlog-articles)))
144 ;; Find the end (i. e., the beginning of the next article).
146 (next-single-property-change
147 (1+ beg) 'gnus-backlog (current-buffer) (point-max)))))
148 (with-current-buffer (or (current-buffer) buffer)
149 (let ((buffer-read-only nil))
151 (insert-buffer-substring gnus-backlog-buffer beg end)))
154 (provide 'gnus-bcklg)
156 ;;; gnus-bcklg.el ends here