1 ;;; gnus-int.el --- backend interface functions for Gnus
2 ;; Copyright (C) 1996 Free Software Foundation, Inc.
4 ;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
7 ;; This file is part of GNU Emacs.
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)
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.
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 the
21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
22 ;; Boston, MA 02111-1307, USA.
31 (defcustom gnus-open-server-hook nil
32 "Hook called just before opening connection to the news server."
37 ;;; Server Communication
40 (defun gnus-start-news-server (&optional confirm)
41 "Open a method for getting news.
42 If CONFIRM is non-nil, the user will be asked for an NNTP server."
44 (if gnus-current-select-method
45 ;; Stream is already opened.
48 (unless gnus-nntp-service
49 (setq gnus-nntp-server nil))
51 ;; Read server name with completion.
52 (setq gnus-nntp-server
53 (completing-read "NNTP server: "
54 (mapcar (lambda (server) (list server))
55 (cons (list gnus-nntp-server)
56 gnus-secondary-servers))
57 nil nil gnus-nntp-server)))
59 (when (and gnus-nntp-server
60 (stringp gnus-nntp-server)
61 (not (string= gnus-nntp-server "")))
62 (setq gnus-select-method
63 (cond ((or (string= gnus-nntp-server "")
64 (string= gnus-nntp-server "::"))
65 (list 'nnspool (system-name)))
66 ((string-match "^:" gnus-nntp-server)
67 (list 'nnmh gnus-nntp-server
69 (file-name-as-directory
71 (concat "~/" (substring
72 gnus-nntp-server 1)))))
73 (list 'nnmh-get-new-mail nil)))
75 (list 'nntp gnus-nntp-server)))))
77 (setq how (car gnus-select-method))
81 (gnus-message 5 "Looking up local news spool..."))
84 (gnus-message 5 "Looking up mh spool..."))
87 (setq gnus-current-select-method gnus-select-method)
88 (run-hooks 'gnus-open-server-hook)
90 ;; gnus-open-server-hook might have opened it
91 (gnus-server-opened gnus-select-method)
92 (gnus-open-server gnus-select-method)
95 "%s (%s) open error: '%s'. Continue? "
96 (car gnus-select-method) (cadr gnus-select-method)
97 (gnus-status-message gnus-select-method)))
98 (gnus-error 1 "Couldn't open server on %s"
99 (nth 1 gnus-select-method))))))
101 (defun gnus-check-group (group)
102 "Try to make sure that the server where GROUP exists is alive."
103 (let ((method (gnus-find-method-for-group group)))
104 (or (gnus-server-opened method)
105 (gnus-open-server method))))
107 (defun gnus-check-server (&optional method silent)
108 "Check whether the connection to METHOD is down.
109 If METHOD is nil, use `gnus-select-method'.
110 If it is down, start it up (again)."
111 (let ((method (or method gnus-select-method)))
112 ;; Transform virtual server names into select methods.
113 (when (stringp method)
114 (setq method (gnus-server-to-method method)))
115 (if (gnus-server-opened method)
116 ;; The stream is already opened.
120 (gnus-message 5 "Opening %s server%s..." (car method)
121 (if (equal (nth 1 method) "") ""
122 (format " on %s" (nth 1 method)))))
123 (run-hooks 'gnus-open-server-hook)
125 (gnus-open-server method)
129 (defun gnus-get-function (method function &optional noerror)
130 "Return a function symbol based on METHOD and FUNCTION."
131 ;; Translate server names into methods.
133 (error "Attempted use of a nil select method"))
134 (when (stringp method)
135 (setq method (gnus-server-to-method method)))
136 (let ((func (intern (format "%s-%s" (car method) function))))
137 ;; If the functions isn't bound, we require the backend in
139 (unless (fboundp func)
140 (require (car method))
141 (when (and (not (fboundp func))
143 ;; This backend doesn't implement this function.
144 (error "No such function: %s" func)))
149 ;;; Interface functions to the backends.
152 (defun gnus-open-server (method)
153 "Open a connection to METHOD."
154 (when (stringp method)
155 (setq method (gnus-server-to-method method)))
156 (let ((elem (assoc method gnus-opened-servers)))
157 ;; If this method was previously denied, we just return nil.
158 (if (eq (nth 1 elem) 'denied)
160 (gnus-message 1 "Denied server")
164 (funcall (gnus-get-function method 'open-server)
165 (nth 1 method) (nthcdr 2 method))))
166 ;; If this hasn't been opened before, we add it to the list.
168 (setq elem (list method nil)
169 gnus-opened-servers (cons elem gnus-opened-servers)))
170 ;; Set the status of this server.
171 (setcar (cdr elem) (if result 'ok 'denied))
172 ;; Return the result from the "open" call.
175 (defun gnus-close-server (method)
176 "Close the connection to METHOD."
177 (when (stringp method)
178 (setq method (gnus-server-to-method method)))
179 (funcall (gnus-get-function method 'close-server) (nth 1 method)))
181 (defun gnus-request-list (method)
182 "Request the active file from METHOD."
183 (when (stringp method)
184 (setq method (gnus-server-to-method method)))
185 (funcall (gnus-get-function method 'request-list) (nth 1 method)))
187 (defun gnus-request-list-newsgroups (method)
188 "Request the newsgroups file from METHOD."
189 (when (stringp method)
190 (setq method (gnus-server-to-method method)))
191 (funcall (gnus-get-function method 'request-list-newsgroups) (nth 1 method)))
193 (defun gnus-request-newgroups (date method)
194 "Request all new groups since DATE from METHOD."
195 (when (stringp method)
196 (setq method (gnus-server-to-method method)))
197 (let ((func (gnus-get-function method 'request-newgroups t)))
199 (funcall func date (nth 1 method)))))
201 (defun gnus-server-opened (method)
202 "Check whether a connection to METHOD has been opened."
203 (when (stringp method)
204 (setq method (gnus-server-to-method method)))
205 (funcall (gnus-get-function method 'server-opened) (nth 1 method)))
207 (defun gnus-status-message (method)
208 "Return the status message from METHOD.
209 If METHOD is a string, it is interpreted as a group name. The method
210 this group uses will be queried."
211 (let ((method (if (stringp method) (gnus-find-method-for-group method)
213 (funcall (gnus-get-function method 'status-message) (nth 1 method))))
215 (defun gnus-request-group (group &optional dont-check method)
216 "Request GROUP. If DONT-CHECK, no information is required."
217 (let ((method (or method (gnus-find-method-for-group group))))
218 (when (stringp method)
219 (setq method (gnus-server-to-method method)))
220 (funcall (gnus-get-function method 'request-group)
221 (gnus-group-real-name group) (nth 1 method) dont-check)))
223 (defun gnus-list-active-group (group)
224 "Request active information on GROUP."
225 (let ((method (gnus-find-method-for-group group))
226 (func 'list-active-group))
227 (when (gnus-check-backend-function func group)
228 (funcall (gnus-get-function method func)
229 (gnus-group-real-name group) (nth 1 method)))))
231 (defun gnus-request-group-description (group)
232 "Request a description of GROUP."
233 (let ((method (gnus-find-method-for-group group))
234 (func 'request-group-description))
235 (when (gnus-check-backend-function func group)
236 (funcall (gnus-get-function method func)
237 (gnus-group-real-name group) (nth 1 method)))))
239 (defun gnus-close-group (group)
240 "Request the GROUP be closed."
241 (let ((method (gnus-find-method-for-group group)))
242 (funcall (gnus-get-function method 'close-group)
243 (gnus-group-real-name group) (nth 1 method))))
245 (defun gnus-retrieve-headers (articles group &optional fetch-old)
246 "Request headers for ARTICLES in GROUP.
247 If FETCH-OLD, retrieve all headers (or some subset thereof) in the group."
248 (let ((method (gnus-find-method-for-group group)))
249 (if (and gnus-use-cache (numberp (car articles)))
250 (gnus-cache-retrieve-headers articles group fetch-old)
251 (funcall (gnus-get-function method 'retrieve-headers)
252 articles (gnus-group-real-name group) (nth 1 method)
255 (defun gnus-retrieve-groups (groups method)
256 "Request active information on GROUPS from METHOD."
257 (when (stringp method)
258 (setq method (gnus-server-to-method method)))
259 (funcall (gnus-get-function method 'retrieve-groups) groups (nth 1 method)))
261 (defun gnus-request-type (group &optional article)
262 "Return the type (`post' or `mail') of GROUP (and ARTICLE)."
263 (let ((method (gnus-find-method-for-group group)))
264 (if (not (gnus-check-backend-function 'request-type (car method)))
266 (funcall (gnus-get-function method 'request-type)
267 (gnus-group-real-name group) article))))
269 (defun gnus-request-update-mark (group article mark)
270 "Return the type (`post' or `mail') of GROUP (and ARTICLE)."
271 (let ((method (gnus-find-method-for-group group)))
272 (if (not (gnus-check-backend-function 'request-update-mark (car method)))
274 (funcall (gnus-get-function method 'request-update-mark)
275 (gnus-group-real-name group) article mark))))
277 (defun gnus-request-article (article group &optional buffer)
278 "Request the ARTICLE in GROUP.
279 ARTICLE can either be an article number or an article Message-ID.
280 If BUFFER, insert the article in that group."
281 (let ((method (gnus-find-method-for-group group)))
282 (funcall (gnus-get-function method 'request-article)
283 article (gnus-group-real-name group) (nth 1 method) buffer)))
285 (defun gnus-request-head (article group)
286 "Request the head of ARTICLE in GROUP."
287 (let* ((method (gnus-find-method-for-group group))
288 (head (gnus-get-function method 'request-head t))
294 (gnus-cache-request-article article group))
295 (setq res (cons group article)
297 ;; Use `head' function.
299 (setq res (funcall head article (gnus-group-real-name group)
301 ;; Use `article' function.
303 (setq res (gnus-request-article article group)
307 (set-buffer nntp-server-buffer)
308 (goto-char (point-min))
309 (when (search-forward "\n\n" nil t)
310 (delete-region (1- (point)) (point-max)))
311 (nnheader-fold-continuation-lines)))
314 (defun gnus-request-body (article group)
315 "Request the body of ARTICLE in GROUP."
316 (let ((method (gnus-find-method-for-group group)))
317 (funcall (gnus-get-function method 'request-body)
318 article (gnus-group-real-name group) (nth 1 method))))
320 (defun gnus-request-post (method)
321 "Post the current buffer using METHOD."
322 (when (stringp method)
323 (setq method (gnus-server-to-method method)))
324 (funcall (gnus-get-function method 'request-post) (nth 1 method)))
326 (defun gnus-request-scan (group method)
327 "Request a SCAN being performed in GROUP from METHOD.
328 If GROUP is nil, all groups on METHOD are scanned."
329 (let ((method (if group (gnus-find-method-for-group group) method)))
330 (funcall (gnus-get-function method 'request-scan)
331 (and group (gnus-group-real-name group)) (nth 1 method))))
333 (defsubst gnus-request-update-info (info method)
334 "Request that METHOD update INFO."
335 (when (stringp method)
336 (setq method (gnus-server-to-method method)))
337 (when (gnus-check-backend-function 'request-update-info (car method))
338 (funcall (gnus-get-function method 'request-update-info)
339 (gnus-group-real-name (gnus-info-group info))
340 info (nth 1 method))))
342 (defun gnus-request-expire-articles (articles group &optional force)
343 (let ((method (gnus-find-method-for-group group)))
344 (funcall (gnus-get-function method 'request-expire-articles)
345 articles (gnus-group-real-name group) (nth 1 method)
348 (defun gnus-request-move-article
349 (article group server accept-function &optional last)
350 (let ((method (gnus-find-method-for-group group)))
351 (funcall (gnus-get-function method 'request-move-article)
352 article (gnus-group-real-name group)
353 (nth 1 method) accept-function last)))
355 (defun gnus-request-accept-article (group method &optional last)
356 ;; Make sure there's a newline at the end of the article.
357 (when (stringp method)
358 (setq method (gnus-server-to-method method)))
359 (when (and (not method)
361 (setq method (gnus-group-name-to-method group)))
362 (goto-char (point-max))
365 (let ((func (car (or method (gnus-find-method-for-group group)))))
366 (funcall (intern (format "%s-request-accept-article" func))
367 (if (stringp group) (gnus-group-real-name group) group)
371 (defun gnus-request-replace-article (article group buffer)
372 (let ((func (car (gnus-find-method-for-group group))))
373 (funcall (intern (format "%s-request-replace-article" func))
374 article (gnus-group-real-name group) buffer)))
376 (defun gnus-request-associate-buffer (group)
377 (let ((method (gnus-find-method-for-group group)))
378 (funcall (gnus-get-function method 'request-associate-buffer)
379 (gnus-group-real-name group))))
381 (defun gnus-request-restore-buffer (article group)
382 "Request a new buffer restored to the state of ARTICLE."
383 (let ((method (gnus-find-method-for-group group)))
384 (funcall (gnus-get-function method 'request-restore-buffer)
385 article (gnus-group-real-name group) (nth 1 method))))
387 (defun gnus-request-create-group (group &optional method args)
388 (when (stringp method)
389 (setq method (gnus-server-to-method method)))
390 (let ((method (or method (gnus-find-method-for-group group))))
391 (funcall (gnus-get-function method 'request-create-group)
392 (gnus-group-real-name group) (nth 1 method) args)))
394 (defun gnus-request-delete-group (group &optional force)
395 (let ((method (gnus-find-method-for-group group)))
396 (funcall (gnus-get-function method 'request-delete-group)
397 (gnus-group-real-name group) force (nth 1 method))))
399 (defun gnus-request-rename-group (group new-name)
400 (let ((method (gnus-find-method-for-group group)))
401 (funcall (gnus-get-function method 'request-rename-group)
402 (gnus-group-real-name group)
403 (gnus-group-real-name new-name) (nth 1 method))))
405 (defun gnus-close-backends ()
406 ;; Send a close request to all backends that support such a request.
407 (let ((methods gnus-valid-select-methods)
409 (while (setq method (pop methods))
410 (when (fboundp (setq func (intern
411 (concat (car method) "-request-close"))))
414 (defun gnus-asynchronous-p (method)
415 (let ((func (gnus-get-function method 'asynchronous-p t)))
419 (defun gnus-remove-denial (method)
420 (when (stringp method)
421 (setq method (gnus-server-to-method method)))
422 (let* ((elem (assoc method gnus-opened-servers))
423 (status (cadr elem)))
424 ;; If this hasn't been opened before, we add it to the list.
425 (when (eq status 'denied)
426 ;; Set the status of this server.
427 (setcar (cdr elem) 'closed))))
431 ;;; gnus-int.el ends here