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41487370 | 1 | ;;; gnus-cache.el --- cache interface for Gnus |
b578f267 | 2 | |
41487370 LMI |
3 | ;; Copyright (C) 1995 Free Software Foundation, Inc. |
4 | ||
5 | ;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no> | |
6 | ;; Keywords: news | |
7 | ||
8 | ;; This file is part of GNU Emacs. | |
9 | ||
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 2, or (at your option) | |
13 | ;; any later version. | |
14 | ||
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. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
b578f267 EN |
21 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
22 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
23 | ;; Boston, MA 02111-1307, USA. | |
41487370 LMI |
24 | |
25 | ;;; Commentary: | |
26 | ||
27 | ;;; Code: | |
28 | ||
29 | (require 'gnus) | |
30 | ||
31 | (defvar gnus-cache-directory (concat gnus-article-save-directory "cache/") | |
32 | "*The directory where cached articles will be stored.") | |
33 | ||
34 | (defvar gnus-cache-enter-articles '(ticked dormant) | |
35 | "*Classes of articles to enter into the cache.") | |
36 | ||
37 | (defvar gnus-cache-remove-articles '(read) | |
38 | "*Classes of articles to remove from the cache.") | |
39 | ||
40 | \f | |
41 | ||
42 | (defvar gnus-cache-buffer nil) | |
43 | ||
44 | \f | |
45 | ||
46 | (defun gnus-cache-change-buffer (group) | |
47 | (and gnus-cache-buffer | |
48 | ;; see if the current group's overview cache has been loaded | |
49 | (or (string= group (car gnus-cache-buffer)) | |
50 | ;; another overview cache is current, save it | |
51 | (gnus-cache-save-buffers))) | |
52 | ;; if gnus-cache buffer is nil, create it | |
53 | (or gnus-cache-buffer | |
54 | ;; create cache buffer | |
55 | (save-excursion | |
56 | (setq gnus-cache-buffer | |
57 | (cons group | |
58 | (set-buffer (get-buffer-create " *gnus-cache-overview*")))) | |
59 | (buffer-disable-undo (current-buffer)) | |
60 | ;; insert the contents of this groups cache overview | |
61 | (erase-buffer) | |
62 | (let ((file (gnus-cache-file-name group ".overview"))) | |
63 | (and (file-exists-p file) | |
64 | (insert-file-contents file))) | |
65 | ;; we have a fresh (empty/just loaded) buffer, | |
66 | ;; mark it as unmodified to save a redundant write later. | |
67 | (set-buffer-modified-p nil)))) | |
68 | ||
69 | ||
70 | (defun gnus-cache-save-buffers () | |
71 | ;; save the overview buffer if it exists and has been modified | |
72 | ;; delete empty cache subdirectories | |
73 | (if (null gnus-cache-buffer) | |
74 | () | |
75 | (let ((buffer (cdr gnus-cache-buffer)) | |
76 | (overview-file (gnus-cache-file-name | |
77 | (car gnus-cache-buffer) ".overview"))) | |
78 | ;; write the overview only if it was modified | |
79 | (if (buffer-modified-p buffer) | |
80 | (save-excursion | |
81 | (set-buffer buffer) | |
82 | (if (> (buffer-size) 0) | |
83 | ;; non-empty overview, write it out | |
84 | (progn | |
85 | (gnus-make-directory (file-name-directory overview-file)) | |
86 | (write-region (point-min) (point-max) | |
87 | overview-file nil 'quietly)) | |
88 | ;; empty overview file, remove it | |
89 | (and (file-exists-p overview-file) | |
90 | (delete-file overview-file)) | |
91 | ;; if possible, remove group's cache subdirectory | |
92 | (condition-case nil | |
93 | ;; FIXME: we can detect the error type and warn the user | |
94 | ;; of any inconsistencies (articles w/o nov entries?). | |
95 | ;; for now, just be conservative...delete only if safe -- sj | |
96 | (delete-directory (file-name-directory overview-file)) | |
97 | (error nil))))) | |
98 | ;; kill the buffer, it's either unmodified or saved | |
99 | (gnus-kill-buffer buffer) | |
100 | (setq gnus-cache-buffer nil)))) | |
101 | ||
102 | ||
103 | ;; Return whether an article is a member of a class. | |
104 | (defun gnus-cache-member-of-class (class ticked dormant unread) | |
105 | (or (and ticked (memq 'ticked class)) | |
106 | (and dormant (memq 'dormant class)) | |
107 | (and unread (memq 'unread class)) | |
108 | (and (not unread) (memq 'read class)))) | |
109 | ||
110 | (defun gnus-cache-file-name (group article) | |
111 | (concat (file-name-as-directory gnus-cache-directory) | |
112 | (if (gnus-use-long-file-name 'not-cache) | |
113 | group | |
114 | (let ((group (concat group ""))) | |
115 | (if (string-match ":" group) | |
116 | (aset group (match-beginning 0) ?/)) | |
117 | (gnus-replace-chars-in-string group ?. ?/))) | |
118 | "/" (if (stringp article) article (int-to-string article)))) | |
119 | ||
120 | (defun gnus-cache-possibly-enter-article | |
121 | (group article headers ticked dormant unread) | |
122 | (let ((number (mail-header-number headers)) | |
123 | file dir) | |
124 | (if (or (not (vectorp headers)) ; This might be a dummy article. | |
125 | (< number 0) ; Reffed article from other group. | |
126 | (not (gnus-cache-member-of-class | |
127 | gnus-cache-enter-articles ticked dormant unread)) | |
128 | (file-exists-p (setq file (gnus-cache-file-name group article)))) | |
129 | () ; Do nothing. | |
130 | ;; Possibly create the cache directory. | |
131 | (or (file-exists-p (setq dir (file-name-directory file))) | |
132 | (gnus-make-directory dir)) | |
133 | ;; Save the article in the cache. | |
134 | (if (file-exists-p file) | |
135 | t ; The article already is saved, so we end here. | |
136 | (let ((gnus-use-cache nil)) | |
137 | (gnus-summary-select-article)) | |
138 | (save-excursion | |
139 | (set-buffer gnus-article-buffer) | |
140 | (save-restriction | |
141 | (widen) | |
142 | (write-region (point-min) (point-max) file nil 'quiet)) | |
143 | (gnus-cache-change-buffer group) | |
144 | (set-buffer (cdr gnus-cache-buffer)) | |
145 | (goto-char (point-max)) | |
146 | (forward-line -1) | |
147 | (while (condition-case () | |
148 | (and (not (bobp)) | |
149 | (> (read (current-buffer)) number)) | |
150 | (error | |
151 | ;; The line was malformed, so we just remove it!! | |
152 | (gnus-delete-line) | |
153 | t)) | |
154 | (forward-line -1)) | |
155 | (if (bobp) | |
156 | (if (not (eobp)) | |
157 | (progn | |
158 | (beginning-of-line) | |
159 | (if (< (read (current-buffer)) number) | |
160 | (forward-line 1))) | |
161 | (beginning-of-line)) | |
162 | (forward-line 1)) | |
163 | (beginning-of-line) | |
164 | ;; [number subject from date id references chars lines xref] | |
165 | (insert (format "%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t\n" | |
166 | (mail-header-number headers) | |
167 | (mail-header-subject headers) | |
168 | (mail-header-from headers) | |
169 | (mail-header-date headers) | |
170 | (mail-header-id headers) | |
171 | (or (mail-header-references headers) "") | |
172 | (or (mail-header-chars headers) "") | |
173 | (or (mail-header-lines headers) "") | |
174 | (or (mail-header-xref headers) "")))) | |
175 | t)))) | |
176 | ||
177 | (defun gnus-cache-enter-remove-article (article) | |
da62804e KH |
178 | (setq gnus-cache-removable-articles |
179 | (cons article gnus-cache-removable-articles))) | |
41487370 LMI |
180 | |
181 | (defsubst gnus-cache-possibly-remove-article | |
182 | (article ticked dormant unread) | |
183 | (let ((file (gnus-cache-file-name gnus-newsgroup-name article))) | |
184 | (if (or (not (file-exists-p file)) | |
185 | (not (gnus-cache-member-of-class | |
186 | gnus-cache-remove-articles ticked dormant unread))) | |
187 | nil | |
188 | (save-excursion | |
189 | (delete-file file) | |
190 | (set-buffer (cdr gnus-cache-buffer)) | |
191 | (goto-char (point-min)) | |
192 | (if (or (looking-at (concat (int-to-string article) "\t")) | |
193 | (search-forward (concat "\n" (int-to-string article) "\t") | |
194 | (point-max) t)) | |
195 | (delete-region (progn (beginning-of-line) (point)) | |
196 | (progn (forward-line 1) (point)))))))) | |
197 | ||
198 | (defun gnus-cache-possibly-remove-articles () | |
da62804e | 199 | (let ((articles gnus-cache-removable-articles) |
41487370 LMI |
200 | (cache-articles (gnus-cache-articles-in-group gnus-newsgroup-name)) |
201 | article) | |
202 | (gnus-cache-change-buffer gnus-newsgroup-name) | |
203 | (while articles | |
204 | (setq article (car articles) | |
205 | articles (cdr articles)) | |
206 | (if (memq article cache-articles) | |
207 | ;; The article was in the cache, so we see whether we are | |
208 | ;; supposed to remove it from the cache. | |
209 | (gnus-cache-possibly-remove-article | |
210 | article (memq article gnus-newsgroup-marked) | |
211 | (memq article gnus-newsgroup-dormant) | |
212 | (or (memq article gnus-newsgroup-unreads) | |
213 | (memq article gnus-newsgroup-unselected)))))) | |
214 | ;; the overview file might have been modified, save it | |
215 | ;; safe because we're only called at group exit anyway | |
216 | (gnus-cache-save-buffers)) | |
217 | ||
218 | ||
219 | (defun gnus-cache-request-article (article group) | |
220 | (let ((file (gnus-cache-file-name group article))) | |
221 | (if (not (file-exists-p file)) | |
222 | () | |
223 | (erase-buffer) | |
224 | ;; There may be some overlays that we have to kill... | |
225 | (insert "i") | |
226 | (let ((overlays (overlays-at (point-min)))) | |
227 | (while overlays | |
228 | (delete-overlay (car overlays)) | |
229 | (setq overlays (cdr overlays)))) | |
230 | (erase-buffer) | |
231 | (insert-file-contents file) | |
232 | t))) | |
233 | ||
234 | (defun gnus-cache-articles-in-group (group) | |
235 | (let ((dir (file-name-directory (gnus-cache-file-name group 1))) | |
236 | articles) | |
237 | (if (not (file-exists-p dir)) | |
238 | nil | |
239 | (setq articles (directory-files dir nil "^[0-9]+$" t)) | |
240 | (if (not articles) | |
241 | nil | |
242 | (sort (mapcar (function (lambda (name) | |
243 | (string-to-int name))) | |
244 | articles) | |
245 | '<))))) | |
246 | ||
247 | (defun gnus-cache-active-articles (group) | |
248 | (let ((articles (gnus-cache-articles-in-group group))) | |
249 | (and articles | |
250 | (cons (car articles) (gnus-last-element articles))))) | |
251 | ||
252 | (defun gnus-cache-possibly-alter-active (group active) | |
253 | (let ((cache-active (gnus-cache-active-articles group))) | |
254 | (and cache-active (< (car cache-active) (car active)) | |
255 | (setcar active (car cache-active))) | |
256 | (and cache-active (> (cdr cache-active) (cdr active)) | |
257 | (setcdr active (cdr cache-active))))) | |
258 | ||
259 | (defun gnus-cache-retrieve-headers (articles group) | |
260 | (let* ((cached (gnus-cache-articles-in-group group)) | |
261 | (articles (gnus-sorted-complement articles cached)) | |
262 | (cache-file (gnus-cache-file-name group ".overview")) | |
263 | type) | |
264 | (let ((gnus-use-cache nil)) | |
265 | (setq type (and articles (gnus-retrieve-headers articles group)))) | |
266 | (gnus-cache-save-buffers) | |
267 | (save-excursion | |
268 | (cond ((not (file-exists-p cache-file)) | |
269 | type) | |
270 | ((null type) | |
271 | (set-buffer nntp-server-buffer) | |
272 | (erase-buffer) | |
273 | (insert-file-contents cache-file) | |
274 | 'nov) | |
275 | ((eq type 'nov) | |
276 | (gnus-cache-braid-nov group cached) | |
277 | type) | |
278 | (t | |
279 | (gnus-cache-braid-heads group cached) | |
280 | type))))) | |
281 | ||
282 | (defun gnus-cache-braid-nov (group cached) | |
283 | (let ((cache-buf (get-buffer-create " *gnus-cache*")) | |
284 | beg end) | |
285 | (gnus-cache-save-buffers) | |
286 | (save-excursion | |
287 | (set-buffer cache-buf) | |
288 | (buffer-disable-undo (current-buffer)) | |
289 | (erase-buffer) | |
290 | (insert-file-contents (gnus-cache-file-name group ".overview")) | |
291 | (goto-char (point-min)) | |
292 | (insert "\n") | |
293 | (goto-char (point-min))) | |
294 | (set-buffer nntp-server-buffer) | |
295 | (goto-char (point-min)) | |
296 | (while cached | |
297 | (while (and (not (eobp)) | |
298 | (< (read (current-buffer)) (car cached))) | |
299 | (forward-line 1)) | |
300 | (beginning-of-line) | |
301 | (save-excursion | |
302 | (set-buffer cache-buf) | |
303 | (if (search-forward (concat "\n" (int-to-string (car cached)) "\t") | |
304 | nil t) | |
305 | (setq beg (progn (beginning-of-line) (point)) | |
306 | end (progn (end-of-line) (point))) | |
307 | (setq beg nil))) | |
308 | (if beg (progn (insert-buffer-substring cache-buf beg end) | |
309 | (insert "\n"))) | |
310 | (setq cached (cdr cached))) | |
311 | (kill-buffer cache-buf))) | |
312 | ||
313 | (defun gnus-cache-braid-heads (group cached) | |
314 | (let ((cache-buf (get-buffer-create " *gnus-cache*"))) | |
315 | (save-excursion | |
316 | (set-buffer cache-buf) | |
317 | (buffer-disable-undo (current-buffer)) | |
318 | (erase-buffer)) | |
319 | (set-buffer nntp-server-buffer) | |
320 | (goto-char (point-min)) | |
321 | (while cached | |
322 | (while (and (not (eobp)) | |
323 | (looking-at "2.. +\\([0-9]+\\) ") | |
324 | (< (progn (goto-char (match-beginning 1)) | |
325 | (read (current-buffer))) | |
326 | (car cached))) | |
327 | (search-forward "\n.\n" nil 'move)) | |
328 | (beginning-of-line) | |
329 | (save-excursion | |
330 | (set-buffer cache-buf) | |
331 | (erase-buffer) | |
332 | (insert-file-contents (gnus-cache-file-name group (car cached))) | |
333 | (goto-char (point-min)) | |
334 | (insert "220 " (int-to-string (car cached)) " Article retrieved.\n") | |
335 | (search-forward "\n\n" nil 'move) | |
336 | (delete-region (point) (point-max)) | |
337 | (forward-char -1) | |
338 | (insert ".")) | |
339 | (insert-buffer-substring cache-buf) | |
340 | (setq cached (cdr cached))) | |
341 | (kill-buffer cache-buf))) | |
342 | ||
343 | (defun gnus-jog-cache () | |
344 | "Go through all groups and put the articles into the cache." | |
345 | (interactive) | |
346 | (let ((newsrc (cdr gnus-newsrc-alist)) | |
347 | (gnus-cache-enter-articles '(unread)) | |
348 | (gnus-mark-article-hook nil) | |
349 | (gnus-expert-user t) | |
350 | (gnus-large-newsgroup nil)) | |
351 | (while newsrc | |
352 | (gnus-summary-read-group (car (car newsrc))) | |
353 | (if (not (eq major-mode 'gnus-summary-mode)) | |
354 | () | |
355 | (while gnus-newsgroup-unreads | |
356 | (gnus-summary-select-article t t nil (car gnus-newsgroup-unreads)) | |
357 | (setq gnus-newsgroup-unreads (cdr gnus-newsgroup-unreads))) | |
358 | (kill-buffer (current-buffer))) | |
359 | (setq newsrc (cdr newsrc))))) | |
360 | ||
361 | (provide 'gnus-cache) | |
362 | ||
363 | ;;; gnus-cache.el ends here |