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41487370 LMI |
1 | ;;; gnus-cache.el --- cache interface for Gnus |
2 | ;; Copyright (C) 1995 Free Software Foundation, Inc. | |
3 | ||
4 | ;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no> | |
5 | ;; Keywords: news | |
6 | ||
7 | ;; This file is part of GNU Emacs. | |
8 | ||
9 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
10 | ;; it under the terms of the GNU General Public License as published by | |
11 | ;; the Free Software Foundation; either version 2, or (at your option) | |
12 | ;; any later version. | |
13 | ||
14 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
15 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | ;; GNU General Public License for more details. | |
18 | ||
19 | ;; You should have received a copy of the GNU General Public License | |
20 | ;; along with GNU Emacs; see the file COPYING. If not, write to | |
21 | ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
22 | ||
23 | ;;; Commentary: | |
24 | ||
25 | ;;; Code: | |
26 | ||
27 | (require 'gnus) | |
28 | ||
29 | (defvar gnus-cache-directory (concat gnus-article-save-directory "cache/") | |
30 | "*The directory where cached articles will be stored.") | |
31 | ||
32 | (defvar gnus-cache-enter-articles '(ticked dormant) | |
33 | "*Classes of articles to enter into the cache.") | |
34 | ||
35 | (defvar gnus-cache-remove-articles '(read) | |
36 | "*Classes of articles to remove from the cache.") | |
37 | ||
38 | \f | |
39 | ||
40 | (defvar gnus-cache-buffer nil) | |
41 | ||
42 | \f | |
43 | ||
44 | (defun gnus-cache-change-buffer (group) | |
45 | (and gnus-cache-buffer | |
46 | ;; see if the current group's overview cache has been loaded | |
47 | (or (string= group (car gnus-cache-buffer)) | |
48 | ;; another overview cache is current, save it | |
49 | (gnus-cache-save-buffers))) | |
50 | ;; if gnus-cache buffer is nil, create it | |
51 | (or gnus-cache-buffer | |
52 | ;; create cache buffer | |
53 | (save-excursion | |
54 | (setq gnus-cache-buffer | |
55 | (cons group | |
56 | (set-buffer (get-buffer-create " *gnus-cache-overview*")))) | |
57 | (buffer-disable-undo (current-buffer)) | |
58 | ;; insert the contents of this groups cache overview | |
59 | (erase-buffer) | |
60 | (let ((file (gnus-cache-file-name group ".overview"))) | |
61 | (and (file-exists-p file) | |
62 | (insert-file-contents file))) | |
63 | ;; we have a fresh (empty/just loaded) buffer, | |
64 | ;; mark it as unmodified to save a redundant write later. | |
65 | (set-buffer-modified-p nil)))) | |
66 | ||
67 | ||
68 | (defun gnus-cache-save-buffers () | |
69 | ;; save the overview buffer if it exists and has been modified | |
70 | ;; delete empty cache subdirectories | |
71 | (if (null gnus-cache-buffer) | |
72 | () | |
73 | (let ((buffer (cdr gnus-cache-buffer)) | |
74 | (overview-file (gnus-cache-file-name | |
75 | (car gnus-cache-buffer) ".overview"))) | |
76 | ;; write the overview only if it was modified | |
77 | (if (buffer-modified-p buffer) | |
78 | (save-excursion | |
79 | (set-buffer buffer) | |
80 | (if (> (buffer-size) 0) | |
81 | ;; non-empty overview, write it out | |
82 | (progn | |
83 | (gnus-make-directory (file-name-directory overview-file)) | |
84 | (write-region (point-min) (point-max) | |
85 | overview-file nil 'quietly)) | |
86 | ;; empty overview file, remove it | |
87 | (and (file-exists-p overview-file) | |
88 | (delete-file overview-file)) | |
89 | ;; if possible, remove group's cache subdirectory | |
90 | (condition-case nil | |
91 | ;; FIXME: we can detect the error type and warn the user | |
92 | ;; of any inconsistencies (articles w/o nov entries?). | |
93 | ;; for now, just be conservative...delete only if safe -- sj | |
94 | (delete-directory (file-name-directory overview-file)) | |
95 | (error nil))))) | |
96 | ;; kill the buffer, it's either unmodified or saved | |
97 | (gnus-kill-buffer buffer) | |
98 | (setq gnus-cache-buffer nil)))) | |
99 | ||
100 | ||
101 | ;; Return whether an article is a member of a class. | |
102 | (defun gnus-cache-member-of-class (class ticked dormant unread) | |
103 | (or (and ticked (memq 'ticked class)) | |
104 | (and dormant (memq 'dormant class)) | |
105 | (and unread (memq 'unread class)) | |
106 | (and (not unread) (memq 'read class)))) | |
107 | ||
108 | (defun gnus-cache-file-name (group article) | |
109 | (concat (file-name-as-directory gnus-cache-directory) | |
110 | (if (gnus-use-long-file-name 'not-cache) | |
111 | group | |
112 | (let ((group (concat group ""))) | |
113 | (if (string-match ":" group) | |
114 | (aset group (match-beginning 0) ?/)) | |
115 | (gnus-replace-chars-in-string group ?. ?/))) | |
116 | "/" (if (stringp article) article (int-to-string article)))) | |
117 | ||
118 | (defun gnus-cache-possibly-enter-article | |
119 | (group article headers ticked dormant unread) | |
120 | (let ((number (mail-header-number headers)) | |
121 | file dir) | |
122 | (if (or (not (vectorp headers)) ; This might be a dummy article. | |
123 | (< number 0) ; Reffed article from other group. | |
124 | (not (gnus-cache-member-of-class | |
125 | gnus-cache-enter-articles ticked dormant unread)) | |
126 | (file-exists-p (setq file (gnus-cache-file-name group article)))) | |
127 | () ; Do nothing. | |
128 | ;; Possibly create the cache directory. | |
129 | (or (file-exists-p (setq dir (file-name-directory file))) | |
130 | (gnus-make-directory dir)) | |
131 | ;; Save the article in the cache. | |
132 | (if (file-exists-p file) | |
133 | t ; The article already is saved, so we end here. | |
134 | (let ((gnus-use-cache nil)) | |
135 | (gnus-summary-select-article)) | |
136 | (save-excursion | |
137 | (set-buffer gnus-article-buffer) | |
138 | (save-restriction | |
139 | (widen) | |
140 | (write-region (point-min) (point-max) file nil 'quiet)) | |
141 | (gnus-cache-change-buffer group) | |
142 | (set-buffer (cdr gnus-cache-buffer)) | |
143 | (goto-char (point-max)) | |
144 | (forward-line -1) | |
145 | (while (condition-case () | |
146 | (and (not (bobp)) | |
147 | (> (read (current-buffer)) number)) | |
148 | (error | |
149 | ;; The line was malformed, so we just remove it!! | |
150 | (gnus-delete-line) | |
151 | t)) | |
152 | (forward-line -1)) | |
153 | (if (bobp) | |
154 | (if (not (eobp)) | |
155 | (progn | |
156 | (beginning-of-line) | |
157 | (if (< (read (current-buffer)) number) | |
158 | (forward-line 1))) | |
159 | (beginning-of-line)) | |
160 | (forward-line 1)) | |
161 | (beginning-of-line) | |
162 | ;; [number subject from date id references chars lines xref] | |
163 | (insert (format "%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t\n" | |
164 | (mail-header-number headers) | |
165 | (mail-header-subject headers) | |
166 | (mail-header-from headers) | |
167 | (mail-header-date headers) | |
168 | (mail-header-id headers) | |
169 | (or (mail-header-references headers) "") | |
170 | (or (mail-header-chars headers) "") | |
171 | (or (mail-header-lines headers) "") | |
172 | (or (mail-header-xref headers) "")))) | |
173 | t)))) | |
174 | ||
175 | (defun gnus-cache-enter-remove-article (article) | |
da62804e KH |
176 | (setq gnus-cache-removable-articles |
177 | (cons article gnus-cache-removable-articles))) | |
41487370 LMI |
178 | |
179 | (defsubst gnus-cache-possibly-remove-article | |
180 | (article ticked dormant unread) | |
181 | (let ((file (gnus-cache-file-name gnus-newsgroup-name article))) | |
182 | (if (or (not (file-exists-p file)) | |
183 | (not (gnus-cache-member-of-class | |
184 | gnus-cache-remove-articles ticked dormant unread))) | |
185 | nil | |
186 | (save-excursion | |
187 | (delete-file file) | |
188 | (set-buffer (cdr gnus-cache-buffer)) | |
189 | (goto-char (point-min)) | |
190 | (if (or (looking-at (concat (int-to-string article) "\t")) | |
191 | (search-forward (concat "\n" (int-to-string article) "\t") | |
192 | (point-max) t)) | |
193 | (delete-region (progn (beginning-of-line) (point)) | |
194 | (progn (forward-line 1) (point)))))))) | |
195 | ||
196 | (defun gnus-cache-possibly-remove-articles () | |
da62804e | 197 | (let ((articles gnus-cache-removable-articles) |
41487370 LMI |
198 | (cache-articles (gnus-cache-articles-in-group gnus-newsgroup-name)) |
199 | article) | |
200 | (gnus-cache-change-buffer gnus-newsgroup-name) | |
201 | (while articles | |
202 | (setq article (car articles) | |
203 | articles (cdr articles)) | |
204 | (if (memq article cache-articles) | |
205 | ;; The article was in the cache, so we see whether we are | |
206 | ;; supposed to remove it from the cache. | |
207 | (gnus-cache-possibly-remove-article | |
208 | article (memq article gnus-newsgroup-marked) | |
209 | (memq article gnus-newsgroup-dormant) | |
210 | (or (memq article gnus-newsgroup-unreads) | |
211 | (memq article gnus-newsgroup-unselected)))))) | |
212 | ;; the overview file might have been modified, save it | |
213 | ;; safe because we're only called at group exit anyway | |
214 | (gnus-cache-save-buffers)) | |
215 | ||
216 | ||
217 | (defun gnus-cache-request-article (article group) | |
218 | (let ((file (gnus-cache-file-name group article))) | |
219 | (if (not (file-exists-p file)) | |
220 | () | |
221 | (erase-buffer) | |
222 | ;; There may be some overlays that we have to kill... | |
223 | (insert "i") | |
224 | (let ((overlays (overlays-at (point-min)))) | |
225 | (while overlays | |
226 | (delete-overlay (car overlays)) | |
227 | (setq overlays (cdr overlays)))) | |
228 | (erase-buffer) | |
229 | (insert-file-contents file) | |
230 | t))) | |
231 | ||
232 | (defun gnus-cache-articles-in-group (group) | |
233 | (let ((dir (file-name-directory (gnus-cache-file-name group 1))) | |
234 | articles) | |
235 | (if (not (file-exists-p dir)) | |
236 | nil | |
237 | (setq articles (directory-files dir nil "^[0-9]+$" t)) | |
238 | (if (not articles) | |
239 | nil | |
240 | (sort (mapcar (function (lambda (name) | |
241 | (string-to-int name))) | |
242 | articles) | |
243 | '<))))) | |
244 | ||
245 | (defun gnus-cache-active-articles (group) | |
246 | (let ((articles (gnus-cache-articles-in-group group))) | |
247 | (and articles | |
248 | (cons (car articles) (gnus-last-element articles))))) | |
249 | ||
250 | (defun gnus-cache-possibly-alter-active (group active) | |
251 | (let ((cache-active (gnus-cache-active-articles group))) | |
252 | (and cache-active (< (car cache-active) (car active)) | |
253 | (setcar active (car cache-active))) | |
254 | (and cache-active (> (cdr cache-active) (cdr active)) | |
255 | (setcdr active (cdr cache-active))))) | |
256 | ||
257 | (defun gnus-cache-retrieve-headers (articles group) | |
258 | (let* ((cached (gnus-cache-articles-in-group group)) | |
259 | (articles (gnus-sorted-complement articles cached)) | |
260 | (cache-file (gnus-cache-file-name group ".overview")) | |
261 | type) | |
262 | (let ((gnus-use-cache nil)) | |
263 | (setq type (and articles (gnus-retrieve-headers articles group)))) | |
264 | (gnus-cache-save-buffers) | |
265 | (save-excursion | |
266 | (cond ((not (file-exists-p cache-file)) | |
267 | type) | |
268 | ((null type) | |
269 | (set-buffer nntp-server-buffer) | |
270 | (erase-buffer) | |
271 | (insert-file-contents cache-file) | |
272 | 'nov) | |
273 | ((eq type 'nov) | |
274 | (gnus-cache-braid-nov group cached) | |
275 | type) | |
276 | (t | |
277 | (gnus-cache-braid-heads group cached) | |
278 | type))))) | |
279 | ||
280 | (defun gnus-cache-braid-nov (group cached) | |
281 | (let ((cache-buf (get-buffer-create " *gnus-cache*")) | |
282 | beg end) | |
283 | (gnus-cache-save-buffers) | |
284 | (save-excursion | |
285 | (set-buffer cache-buf) | |
286 | (buffer-disable-undo (current-buffer)) | |
287 | (erase-buffer) | |
288 | (insert-file-contents (gnus-cache-file-name group ".overview")) | |
289 | (goto-char (point-min)) | |
290 | (insert "\n") | |
291 | (goto-char (point-min))) | |
292 | (set-buffer nntp-server-buffer) | |
293 | (goto-char (point-min)) | |
294 | (while cached | |
295 | (while (and (not (eobp)) | |
296 | (< (read (current-buffer)) (car cached))) | |
297 | (forward-line 1)) | |
298 | (beginning-of-line) | |
299 | (save-excursion | |
300 | (set-buffer cache-buf) | |
301 | (if (search-forward (concat "\n" (int-to-string (car cached)) "\t") | |
302 | nil t) | |
303 | (setq beg (progn (beginning-of-line) (point)) | |
304 | end (progn (end-of-line) (point))) | |
305 | (setq beg nil))) | |
306 | (if beg (progn (insert-buffer-substring cache-buf beg end) | |
307 | (insert "\n"))) | |
308 | (setq cached (cdr cached))) | |
309 | (kill-buffer cache-buf))) | |
310 | ||
311 | (defun gnus-cache-braid-heads (group cached) | |
312 | (let ((cache-buf (get-buffer-create " *gnus-cache*"))) | |
313 | (save-excursion | |
314 | (set-buffer cache-buf) | |
315 | (buffer-disable-undo (current-buffer)) | |
316 | (erase-buffer)) | |
317 | (set-buffer nntp-server-buffer) | |
318 | (goto-char (point-min)) | |
319 | (while cached | |
320 | (while (and (not (eobp)) | |
321 | (looking-at "2.. +\\([0-9]+\\) ") | |
322 | (< (progn (goto-char (match-beginning 1)) | |
323 | (read (current-buffer))) | |
324 | (car cached))) | |
325 | (search-forward "\n.\n" nil 'move)) | |
326 | (beginning-of-line) | |
327 | (save-excursion | |
328 | (set-buffer cache-buf) | |
329 | (erase-buffer) | |
330 | (insert-file-contents (gnus-cache-file-name group (car cached))) | |
331 | (goto-char (point-min)) | |
332 | (insert "220 " (int-to-string (car cached)) " Article retrieved.\n") | |
333 | (search-forward "\n\n" nil 'move) | |
334 | (delete-region (point) (point-max)) | |
335 | (forward-char -1) | |
336 | (insert ".")) | |
337 | (insert-buffer-substring cache-buf) | |
338 | (setq cached (cdr cached))) | |
339 | (kill-buffer cache-buf))) | |
340 | ||
341 | (defun gnus-jog-cache () | |
342 | "Go through all groups and put the articles into the cache." | |
343 | (interactive) | |
344 | (let ((newsrc (cdr gnus-newsrc-alist)) | |
345 | (gnus-cache-enter-articles '(unread)) | |
346 | (gnus-mark-article-hook nil) | |
347 | (gnus-expert-user t) | |
348 | (gnus-large-newsgroup nil)) | |
349 | (while newsrc | |
350 | (gnus-summary-read-group (car (car newsrc))) | |
351 | (if (not (eq major-mode 'gnus-summary-mode)) | |
352 | () | |
353 | (while gnus-newsgroup-unreads | |
354 | (gnus-summary-select-article t t nil (car gnus-newsgroup-unreads)) | |
355 | (setq gnus-newsgroup-unreads (cdr gnus-newsgroup-unreads))) | |
356 | (kill-buffer (current-buffer))) | |
357 | (setq newsrc (cdr newsrc))))) | |
358 | ||
359 | (provide 'gnus-cache) | |
360 | ||
361 | ;;; gnus-cache.el ends here |