1 ;;; gnus-cache.el --- cache interface for Gnus
2 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
3 ;; Free Software Foundation, Inc.
5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
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 2, or (at your option)
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; 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.
29 (eval-when-compile (require 'cl))
36 (if (not (fboundp 'gnus-agent-load-alist))
37 (defun gnus-agent-load-alist (group)))
40 (defcustom gnus-cache-active-file
41 (expand-file-name "active" gnus-cache-directory)
42 "*The cache active file."
46 (defcustom gnus-cache-enter-articles '(ticked dormant)
47 "Classes of articles to enter into the cache."
49 :type '(set (const ticked) (const dormant) (const unread) (const read)))
51 (defcustom gnus-cache-remove-articles '(read)
52 "Classes of articles to remove from the cache."
54 :type '(set (const ticked) (const dormant) (const unread) (const read)))
56 (defcustom gnus-cacheable-groups nil
57 "*Groups that match this regexp will be cached.
59 If you only want to cache your nntp groups, you could set this
60 variable to \"^nntp\".
62 If a group matches both gnus-cacheable-groups and gnus-uncacheable-groups
65 :type '(choice (const :tag "off" nil)
68 (defcustom gnus-uncacheable-groups nil
69 "*Groups that match this regexp will not be cached.
71 If you want to avoid caching your nnml groups, you could set this
72 variable to \"^nnml\".
74 If a group matches both gnus-cacheable-groups and gnus-uncacheable-groups
77 :type '(choice (const :tag "off" nil)
80 (defvar gnus-cache-overview-coding-system 'raw-text
81 "Coding system used on Gnus cache files.")
83 (defvar gnus-cache-coding-system 'raw-text
84 "Coding system used on Gnus cache files.")
88 ;;; Internal variables.
90 (defvar gnus-cache-removable-articles nil)
91 (defvar gnus-cache-buffer nil)
92 (defvar gnus-cache-active-hashtb nil)
93 (defvar gnus-cache-active-altered nil)
96 (autoload 'nnml-generate-nov-databases-1 "nnml")
97 (autoload 'nnvirtual-find-group-art "nnvirtual"))
101 ;;; Functions called from Gnus.
103 (defun gnus-cache-open ()
104 "Initialize the cache."
105 (when (or (file-exists-p gnus-cache-directory)
107 (not (eq gnus-use-cache 'passive))))
108 (gnus-cache-read-active)))
110 ;; Complexities of byte-compiling make this kludge necessary. Eeek.
112 (gnus-add-shutdown 'gnus-cache-close 'gnus))
114 (defun gnus-cache-close ()
115 "Shut down the cache."
116 (gnus-cache-write-active)
117 (gnus-cache-save-buffers)
118 (setq gnus-cache-active-hashtb nil))
120 (defun gnus-cache-save-buffers ()
121 ;; save the overview buffer if it exists and has been modified
122 ;; delete empty cache subdirectories
123 (when gnus-cache-buffer
124 (let ((buffer (cdr gnus-cache-buffer))
125 (overview-file (gnus-cache-file-name
126 (car gnus-cache-buffer) ".overview")))
127 ;; write the overview only if it was modified
128 (when (buffer-modified-p buffer)
131 (if (> (buffer-size) 0)
132 ;; Non-empty overview, write it to a file.
133 (let ((coding-system-for-write
134 gnus-cache-overview-coding-system))
135 (gnus-write-buffer overview-file))
136 ;; Empty overview file, remove it
137 (when (file-exists-p overview-file)
138 (delete-file overview-file))
139 ;; If possible, remove group's cache subdirectory.
141 ;; FIXME: we can detect the error type and warn the user
142 ;; of any inconsistencies (articles w/o nov entries?).
143 ;; for now, just be conservative...delete only if safe -- sj
144 (delete-directory (file-name-directory overview-file))
146 ;; Kill the buffer -- it's either unmodified or saved.
147 (gnus-kill-buffer buffer)
148 (setq gnus-cache-buffer nil))))
150 (defun gnus-cache-possibly-enter-article
151 (group article ticked dormant unread &optional force)
152 (when (and (or force (not (eq gnus-use-cache 'passive)))
154 (> article 0)) ; This might be a dummy article.
155 (let ((number article) file headers)
156 ;; If this is a virtual group, we find the real group.
157 (when (gnus-virtual-group-p group)
158 (let ((result (nnvirtual-find-group-art
159 (gnus-group-real-name group) article)))
160 (setq group (car result)
161 number (cdr result))))
163 (> number 0) ; Reffed article.
165 (and (gnus-cache-fully-p group)
166 (gnus-cache-member-of-class
167 gnus-cache-enter-articles ticked dormant unread)))
168 (not (file-exists-p (setq file (gnus-cache-file-name
170 ;; Possibly create the cache directory.
171 (gnus-make-directory (file-name-directory file))
172 ;; Save the article in the cache.
173 (if (file-exists-p file)
174 t ; The article already is saved.
176 (set-buffer nntp-server-buffer)
178 (let ((gnus-use-cache nil)
179 (gnus-article-decode-hook nil))
180 (gnus-request-article-this-buffer number group))
181 (when (> (buffer-size) 0)
182 (let ((coding-system-for-write gnus-cache-coding-system))
183 (gnus-write-buffer file))
184 (nnheader-remove-body)
185 (setq headers (nnheader-parse-naked-head))
186 (mail-header-set-number headers number)
187 (gnus-cache-change-buffer group)
188 (set-buffer (cdr gnus-cache-buffer))
189 (goto-char (point-max))
191 (while (condition-case ()
193 (> (read (current-buffer)) number))
195 ;; The line was malformed, so we just remove it!!
203 (when (< (read (current-buffer)) number)
208 (nnheader-insert-nov headers)
209 ;; Update the active info.
210 (set-buffer gnus-summary-buffer)
211 (gnus-cache-possibly-update-active group (cons number number))
212 (setq gnus-newsgroup-cached
213 (gnus-add-to-sorted-list gnus-newsgroup-cached article))
214 (gnus-summary-update-secondary-mark article))
217 (defun gnus-cache-enter-remove-article (article)
218 "Mark ARTICLE for later possible removal."
220 (push article gnus-cache-removable-articles)))
222 (defun gnus-cache-possibly-remove-articles ()
223 "Possibly remove some of the removable articles."
224 (if (not (gnus-virtual-group-p gnus-newsgroup-name))
225 (gnus-cache-possibly-remove-articles-1)
226 (let ((arts gnus-cache-removable-articles)
229 (when (setq ga (nnvirtual-find-group-art
230 (gnus-group-real-name gnus-newsgroup-name) (pop arts)))
231 (let ((gnus-cache-removable-articles (list (cdr ga)))
232 (gnus-newsgroup-name (car ga)))
233 (gnus-cache-possibly-remove-articles-1)))))
234 (setq gnus-cache-removable-articles nil)))
236 (defun gnus-cache-possibly-remove-articles-1 ()
237 "Possibly remove some of the removable articles."
238 (when (gnus-cache-fully-p gnus-newsgroup-name)
239 (let ((articles gnus-cache-removable-articles)
240 (cache-articles gnus-newsgroup-cached)
242 (gnus-cache-change-buffer gnus-newsgroup-name)
244 (when (memq (setq article (pop articles)) cache-articles)
245 ;; The article was in the cache, so we see whether we are
246 ;; supposed to remove it from the cache.
247 (gnus-cache-possibly-remove-article
248 article (memq article gnus-newsgroup-marked)
249 (memq article gnus-newsgroup-dormant)
250 (or (memq article gnus-newsgroup-unreads)
251 (memq article gnus-newsgroup-unselected))))))
252 ;; The overview file might have been modified, save it
253 ;; safe because we're only called at group exit anyway.
254 (gnus-cache-save-buffers)))
256 (defun gnus-cache-request-article (article group)
257 "Retrieve ARTICLE in GROUP from the cache."
258 (let ((file (gnus-cache-file-name group article))
259 (buffer-read-only nil))
260 (when (file-exists-p file)
262 (gnus-kill-all-overlays)
263 (let ((coding-system-for-read gnus-cache-coding-system))
264 (insert-file-contents file))
267 (defun gnus-cache-possibly-alter-active (group active)
268 "Alter the ACTIVE info for GROUP to reflect the articles in the cache."
269 (when gnus-cache-active-hashtb
270 (let ((cache-active (gnus-gethash group gnus-cache-active-hashtb)))
272 (when (< (car cache-active) (car active))
273 (setcar active (car cache-active)))
274 (when (> (cdr cache-active) (cdr active))
275 (setcdr active (cdr cache-active)))))))
277 (defun gnus-cache-retrieve-headers (articles group &optional fetch-old)
278 "Retrieve the headers for ARTICLES in GROUP."
280 (setq gnus-newsgroup-cached (gnus-cache-articles-in-group group))))
282 ;; No cached articles here, so we just retrieve them
284 (let ((gnus-use-cache nil))
285 (gnus-retrieve-headers articles group fetch-old))
286 (let ((uncached-articles (gnus-sorted-difference articles cached))
287 (cache-file (gnus-cache-file-name group ".overview"))
289 ;; We first retrieve all the headers that we don't have in
291 (let ((gnus-use-cache nil))
292 (when uncached-articles
293 (setq type (and articles
294 (gnus-retrieve-headers
295 uncached-articles group fetch-old)))))
296 (gnus-cache-save-buffers)
297 ;; Then we insert the cached headers.
300 ((not (file-exists-p cache-file))
301 ;; There are no cached headers.
304 ;; There were no uncached headers (or retrieval was
305 ;; unsuccessful), so we use the cached headers exclusively.
306 (set-buffer nntp-server-buffer)
308 (let ((coding-system-for-read
309 gnus-cache-overview-coding-system))
310 (insert-file-contents cache-file))
313 ;; We have both cached and uncached NOV headers, so we
315 (gnus-cache-braid-nov group cached)
319 (gnus-cache-braid-heads group (gnus-sorted-intersection
323 (defun gnus-cache-enter-article (&optional n)
324 "Enter the next N articles into the cache.
325 If not given a prefix, use the process marked articles instead.
326 Returns the list of articles entered."
328 (let ((articles (gnus-summary-work-articles n))
330 (while (setq article (pop articles))
331 (gnus-summary-remove-process-mark article)
332 (if (natnump article)
333 (when (gnus-cache-possibly-enter-article
334 gnus-newsgroup-name article
336 (setq gnus-newsgroup-undownloaded (delq article gnus-newsgroup-undownloaded))
338 (gnus-message 2 "Can't cache article %d" article))
339 (gnus-summary-update-download-mark article)
340 (gnus-summary-update-secondary-mark article))
341 (gnus-summary-next-subject 1)
342 (gnus-summary-position-point)
345 (defun gnus-cache-remove-article (&optional n)
346 "Remove the next N articles from the cache.
347 If not given a prefix, use the process marked articles instead.
348 Returns the list of articles removed."
350 (gnus-cache-change-buffer gnus-newsgroup-name)
351 (let ((articles (gnus-summary-work-articles n))
354 (setq article (pop articles))
355 (gnus-summary-remove-process-mark article)
356 (when (gnus-cache-possibly-remove-article article nil nil nil t)
357 (when gnus-newsgroup-agentized
358 (let ((alist (gnus-agent-load-alist gnus-newsgroup-name)))
359 (unless (cdr (assoc article alist))
360 (setq gnus-newsgroup-undownloaded
361 (gnus-add-to-sorted-list
362 gnus-newsgroup-undownloaded article)))))
364 (gnus-summary-update-download-mark article)
365 (gnus-summary-update-secondary-mark article))
366 (gnus-summary-next-subject 1)
367 (gnus-summary-position-point)
370 (defun gnus-cached-article-p (article)
371 "Say whether ARTICLE is cached in the current group."
372 (memq article gnus-newsgroup-cached))
374 (defun gnus-summary-insert-cached-articles ()
375 "Insert all the articles cached for this group into the current buffer."
377 (let ((gnus-verbose (max 6 gnus-verbose)))
378 (if (not gnus-newsgroup-cached)
379 (gnus-message 3 "No cached articles for this group")
380 (gnus-summary-goto-subjects gnus-newsgroup-cached))))
382 (defun gnus-summary-limit-include-cached ()
383 "Limit the summary buffer to articles that are cached."
385 (let ((gnus-verbose (max 6 gnus-verbose)))
386 (if gnus-newsgroup-cached
388 (gnus-summary-limit gnus-newsgroup-cached)
389 (gnus-summary-position-point))
390 (gnus-message 3 "No cached articles for this group"))))
392 ;;; Internal functions.
394 (defun gnus-cache-change-buffer (group)
395 (and gnus-cache-buffer
396 ;; See if the current group's overview cache has been loaded.
397 (or (string= group (car gnus-cache-buffer))
398 ;; Another overview cache is current, save it.
399 (gnus-cache-save-buffers)))
400 ;; if gnus-cache buffer is nil, create it
401 (unless gnus-cache-buffer
402 ;; Create cache buffer
404 (setq gnus-cache-buffer
406 (set-buffer (gnus-get-buffer-create
407 " *gnus-cache-overview*"))))
408 ;; Insert the contents of this group's cache overview.
410 (let ((file (gnus-cache-file-name group ".overview")))
411 (when (file-exists-p file)
412 (nnheader-insert-file-contents file)))
413 ;; We have a fresh (empty/just loaded) buffer,
414 ;; mark it as unmodified to save a redundant write later.
415 (set-buffer-modified-p nil))))
417 ;; Return whether an article is a member of a class.
418 (defun gnus-cache-member-of-class (class ticked dormant unread)
419 (or (and ticked (memq 'ticked class))
420 (and dormant (memq 'dormant class))
421 (and unread (memq 'unread class))
422 (and (not unread) (not ticked) (not dormant) (memq 'read class))))
424 (defun gnus-cache-file-name (group article)
426 (if (stringp article) article (int-to-string article))
427 (file-name-as-directory