code.delx.au - gnu-emacs/blob - lisp/gnus/gnus-int.el

   1 ;;; gnus-int.el --- backend interface functions for Gnus
   2 ;; Copyright (C) 1996,97 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 the
  21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22 ;; Boston, MA 02111-1307, USA.
  23
  24 ;;; Commentary:
  25
  26 ;;; Code:
  27
  28 (eval-when-compile (require 'cl))
  29
  30 (require 'gnus)
  31
  32 (defcustom gnus-open-server-hook nil
  33   "Hook called just before opening connection to the news server."
  34   :group 'gnus-start
  35   :type 'hook)
  36
  37 ;;;
  38 ;;; Server Communication
  39 ;;;
  40
  41 (defun gnus-start-news-server (&optional confirm)
  42   "Open a method for getting news.
  43 If CONFIRM is non-nil, the user will be asked for an NNTP server."
  44   (let (how)
  45     (if gnus-current-select-method
  46         ;; Stream is already opened.
  47         nil
  48       ;; Open NNTP server.
  49       (unless gnus-nntp-service
  50         (setq gnus-nntp-server nil))
  51       (when confirm
  52         ;; Read server name with completion.
  53         (setq gnus-nntp-server
  54               (completing-read "NNTP server: "
  55                                (mapcar (lambda (server) (list server))
  56                                        (cons (list gnus-nntp-server)
  57                                              gnus-secondary-servers))
  58                                nil nil gnus-nntp-server)))
  59
  60       (when (and gnus-nntp-server
  61                  (stringp gnus-nntp-server)
  62                  (not (string= gnus-nntp-server "")))
  63         (setq gnus-select-method
  64               (cond ((or (string= gnus-nntp-server "")
  65                          (string= gnus-nntp-server "::"))
  66                      (list 'nnspool (system-name)))
  67                     ((string-match "^:" gnus-nntp-server)
  68                      (list 'nnmh gnus-nntp-server
  69                            (list 'nnmh-directory
  70                                  (file-name-as-directory
  71                                   (expand-file-name
  72                                    (concat "~/" (substring
  73                                                  gnus-nntp-server 1)))))
  74                            (list 'nnmh-get-new-mail nil)))
  75                     (t
  76                      (list 'nntp gnus-nntp-server)))))
  77
  78       (setq how (car gnus-select-method))
  79       (cond
  80        ((eq how 'nnspool)
  81         (require 'nnspool)
  82         (gnus-message 5 "Looking up local news spool..."))
  83        ((eq how 'nnmh)
  84         (require 'nnmh)
  85         (gnus-message 5 "Looking up mh spool..."))
  86        (t
  87         (require 'nntp)))
  88       (setq gnus-current-select-method gnus-select-method)
  89       (run-hooks 'gnus-open-server-hook)
  90       (or
  91        ;; gnus-open-server-hook might have opened it
  92        (gnus-server-opened gnus-select-method)
  93        (gnus-open-server gnus-select-method)
  94        (gnus-y-or-n-p
  95         (format
  96          "%s (%s) open error: '%s'.  Continue? "
  97          (car gnus-select-method) (cadr gnus-select-method)
  98          (gnus-status-message gnus-select-method)))
  99        (gnus-error 1 "Couldn't open server on %s"
 100                    (nth 1 gnus-select-method))))))
 101
 102 (defun gnus-check-group (group)
 103   "Try to make sure that the server where GROUP exists is alive."
 104   (let ((method (gnus-find-method-for-group group)))
 105     (or (gnus-server-opened method)
 106         (gnus-open-server method))))
 107
 108 (defun gnus-check-server (&optional method silent)
 109   "Check whether the connection to METHOD is down.
 110 If METHOD is nil, use `gnus-select-method'.
 111 If it is down, start it up (again)."
 112   (let ((method (or method gnus-select-method)))
 113     ;; Transform virtual server names into select methods.
 114     (when (stringp method)
 115       (setq method (gnus-server-to-method method)))
 116     (if (gnus-server-opened method)
 117         ;; The stream is already opened.
 118         t
 119       ;; Open the server.
 120       (unless silent
 121         (gnus-message 5 "Opening %s server%s..." (car method)
 122                       (if (equal (nth 1 method) "") ""
 123                         (format " on %s" (nth 1 method)))))
 124       (run-hooks 'gnus-open-server-hook)
 125       (prog1
 126           (gnus-open-server method)
 127         (unless silent
 128           (message ""))))))
 129
 130 (defun gnus-get-function (method function &optional noerror)
 131   "Return a function symbol based on METHOD and FUNCTION."
 132   ;; Translate server names into methods.
 133   (unless method
 134     (error "Attempted use of a nil select method"))
 135   (when (stringp method)
 136     (setq method (gnus-server-to-method method)))
 137   (let ((func (intern (format "%s-%s" (car method) function))))
 138     ;; If the functions isn't bound, we require the backend in
 139     ;; question.
 140     (unless (fboundp func)
 141       (require (car method))
 142       (when (and (not (fboundp func))
 143                  (not noerror))
 144         ;; This backend doesn't implement this function.
 145         (error "No such function: %s" func)))
 146     func))
 147
 148 \f
 149 ;;;
 150 ;;; Interface functions to the backends.
 151 ;;;
 152
 153 (defun gnus-open-server (method)
 154   "Open a connection to METHOD."
 155   (when (stringp method)
 156     (setq method (gnus-server-to-method method)))
 157   (let ((elem (assoc method gnus-opened-servers)))
 158     ;; If this method was previously denied, we just return nil.
 159     (if (eq (nth 1 elem) 'denied)
 160         (progn
 161           (gnus-message 1 "Denied server")
 162           nil)
 163       ;; Open the server.
 164       (let ((result
 165              (funcall (gnus-get-function method 'open-server)
 166                       (nth 1 method) (nthcdr 2 method))))
 167         ;; If this hasn't been opened before, we add it to the list.
 168         (unless elem
 169           (setq elem (list method nil)
 170                 gnus-opened-servers (cons elem gnus-opened-servers)))
 171         ;; Set the status of this server.
 172         (setcar (cdr elem) (if result 'ok 'denied))
 173         ;; Return the result from the "open" call.
 174         result))))
 175
 176 (defun gnus-close-server (method)
 177   "Close the connection to METHOD."
 178   (when (stringp method)
 179     (setq method (gnus-server-to-method method)))
 180   (funcall (gnus-get-function method 'close-server) (nth 1 method)))
 181
 182 (defun gnus-request-list (method)
 183   "Request the active file from METHOD."
 184   (when (stringp method)
 185     (setq method (gnus-server-to-method method)))
 186   (funcall (gnus-get-function method 'request-list) (nth 1 method)))
 187
 188 (defun gnus-request-list-newsgroups (method)
 189   "Request the newsgroups file from METHOD."
 190   (when (stringp method)
 191     (setq method (gnus-server-to-method method)))
 192   (funcall (gnus-get-function method 'request-list-newsgroups) (nth 1 method)))
 193
 194 (defun gnus-request-newgroups (date method)
 195   "Request all new groups since DATE from METHOD."
 196   (when (stringp method)
 197     (setq method (gnus-server-to-method method)))
 198   (let ((func (gnus-get-function method 'request-newgroups t)))
 199     (when func
 200       (funcall func date (nth 1 method)))))
 201
 202 (defun gnus-server-opened (method)
 203   "Check whether a connection to METHOD has been opened."
 204   (when (stringp method)
 205     (setq method (gnus-server-to-method method)))
 206   (funcall (inline (gnus-get-function method 'server-opened)) (nth 1 method)))
 207
 208 (defun gnus-status-message (method)
 209   "Return the status message from METHOD.
 210 If METHOD is a string, it is interpreted as a group name.   The method
 211 this group uses will be queried."
 212   (let ((method (if (stringp method) (gnus-find-method-for-group method)
 213                   method)))
 214     (funcall (gnus-get-function method 'status-message) (nth 1 method))))
 215
 216 (defun gnus-request-regenerate (method)
 217   "Request a data generation from METHOD."
 218   (when (stringp method)
 219     (setq method (gnus-server-to-method method)))
 220   (funcall (gnus-get-function method 'request-regenerate) (nth 1 method)))
 221
 222 (defun gnus-request-group (group &optional dont-check method)
 223   "Request GROUP.  If DONT-CHECK, no information is required."
 224   (let ((method (or method (inline (gnus-find-method-for-group group)))))
 225     (when (stringp method)
 226       (setq method (inline (gnus-server-to-method method))))
 227     (funcall (inline (gnus-get-function method 'request-group))
 228              (gnus-group-real-name group) (nth 1 method) dont-check)))
 229
 230 (defun gnus-list-active-group (group)
 231   "Request active information on GROUP."
 232   (let ((method (gnus-find-method-for-group group))
 233         (func 'list-active-group))
 234     (when (gnus-check-backend-function func group)
 235       (funcall (gnus-get-function method func)
 236                (gnus-group-real-name group) (nth 1 method)))))
 237
 238 (defun gnus-request-group-description (group)
 239   "Request a description of GROUP."
 240   (let ((method (gnus-find-method-for-group group))
 241         (func 'request-group-description))
 242     (when (gnus-check-backend-function func group)
 243       (funcall (gnus-get-function method func)
 244                (gnus-group-real-name group) (nth 1 method)))))
 245
 246 (defun gnus-close-group (group)
 247   "Request the GROUP be closed."
 248   (let ((method (inline (gnus-find-method-for-group group))))
 249     (funcall (gnus-get-function method 'close-group)
 250              (gnus-group-real-name group) (nth 1 method))))
 251
 252 (defun gnus-retrieve-headers (articles group &optional fetch-old)
 253   "Request headers for ARTICLES in GROUP.
 254 If FETCH-OLD, retrieve all headers (or some subset thereof) in the group."
 255   (let ((method (gnus-find-method-for-group group)))
 256     (if (and gnus-use-cache (numberp (car articles)))
 257         (gnus-cache-retrieve-headers articles group fetch-old)
 258       (funcall (gnus-get-function method 'retrieve-headers)
 259                articles (gnus-group-real-name group) (nth 1 method)
 260                fetch-old))))
 261
 262 (defun gnus-retrieve-groups (groups method)
 263   "Request active information on GROUPS from METHOD."
 264   (when (stringp method)
 265     (setq method (gnus-server-to-method method)))
 266   (funcall (gnus-get-function method 'retrieve-groups) groups (nth 1 method)))
 267
 268 (defun gnus-request-type (group &optional article)
 269   "Return the type (`post' or `mail') of GROUP (and ARTICLE)."
 270   (let ((method (gnus-find-method-for-group group)))
 271     (if (not (gnus-check-backend-function 'request-type (car method)))
 272         'unknown
 273       (funcall (gnus-get-function method 'request-type)
 274                (gnus-group-real-name group) article))))
 275
 276 (defun gnus-request-update-mark (group article mark)
 277   "Return the type (`post' or `mail') of GROUP (and ARTICLE)."
 278   (let ((method (gnus-find-method-for-group group)))
 279     (if (not (gnus-check-backend-function 'request-update-mark (car method)))
 280         mark
 281       (funcall (gnus-get-function method 'request-update-mark)
 282                (gnus-group-real-name group) article mark))))
 283
 284 (defun gnus-request-article (article group &optional buffer)
 285   "Request the ARTICLE in GROUP.
 286 ARTICLE can either be an article number or an article Message-ID.
 287 If BUFFER, insert the article in that group."
 288   (let ((method (gnus-find-method-for-group group)))
 289     (funcall (gnus-get-function method 'request-article)
 290              article (gnus-group-real-name group) (nth 1 method) buffer)))
 291
 292 (defun gnus-request-head (article group)
 293   "Request the head of ARTICLE in GROUP."
 294   (let* ((method (gnus-find-method-for-group group))
 295          (head (gnus-get-function method 'request-head t))
 296          res clean-up)
 297     (cond
 298      ;; Check the cache.
 299      ((and gnus-use-cache
 300            (numberp article)
 301            (gnus-cache-request-article article group))
 302       (setq res (cons group article)
 303             clean-up t))
 304      ;; Use `head' function.
 305      ((fboundp head)
 306       (setq res (funcall head article (gnus-group-real-name group)
 307                          (nth 1 method))))
 308      ;; Use `article' function.
 309      (t
 310       (setq res (gnus-request-article article group)
 311             clean-up t)))
 312     (when clean-up
 313       (save-excursion
 314         (set-buffer nntp-server-buffer)
 315         (goto-char (point-min))
 316         (when (search-forward "\n\n" nil t)
 317           (delete-region (1- (point)) (point-max)))
 318         (nnheader-fold-continuation-lines)))
 319     res))
 320
 321 (defun gnus-request-body (article group)
 322   "Request the body of ARTICLE in GROUP."
 323   (let ((method (gnus-find-method-for-group group)))
 324     (funcall (gnus-get-function method 'request-body)
 325              article (gnus-group-real-name group) (nth 1 method))))
 326
 327 (defun gnus-request-post (method)
 328   "Post the current buffer using METHOD."
 329   (when (stringp method)
 330     (setq method (gnus-server-to-method method)))
 331   (funcall (gnus-get-function method 'request-post) (nth 1 method)))
 332
 333 (defun gnus-request-scan (group method)
 334   "Request a SCAN being performed in GROUP from METHOD.
 335 If GROUP is nil, all groups on METHOD are scanned."
 336   (let ((method (if group (gnus-find-method-for-group group) method))
 337         (gnus-inhibit-demon t))
 338     (funcall (gnus-get-function method 'request-scan)
 339              (and group (gnus-group-real-name group)) (nth 1 method))))
 340
 341 (defsubst gnus-request-update-info (info method)
 342   "Request that METHOD update INFO."
 343   (when (stringp method)
 344     (setq method (gnus-server-to-method method)))
 345   (when (gnus-check-backend-function 'request-update-info (car method))
 346     (funcall (gnus-get-function method 'request-update-info)
 347              (gnus-group-real-name (gnus-info-group info))
 348              info (nth 1 method))))
 349
 350 (defun gnus-request-expire-articles (articles group &optional force)
 351   (let ((method (gnus-find-method-for-group group)))
 352     (funcall (gnus-get-function method 'request-expire-articles)
 353              articles (gnus-group-real-name group) (nth 1 method)
 354              force)))
 355
 356 (defun gnus-request-move-article
 357   (article group server accept-function &optional last)
 358   (let ((method (gnus-find-method-for-group group)))
 359     (funcall (gnus-get-function method 'request-move-article)
 360              article (gnus-group-real-name group)
 361              (nth 1 method) accept-function last)))
 362
 363 (defun gnus-request-accept-article (group method &optional last)
 364   ;; Make sure there's a newline at the end of the article.
 365   (when (stringp method)
 366     (setq method (gnus-server-to-method method)))
 367   (when (and (not method)
 368              (stringp group))
 369     (setq method (gnus-group-name-to-method group)))
 370   (goto-char (point-max))
 371   (unless (bolp)
 372     (insert "\n"))
 373   (let ((func (car (or method (gnus-find-method-for-group group)))))
 374     (funcall (intern (format "%s-request-accept-article" func))
 375              (if (stringp group) (gnus-group-real-name group) group)
 376              (cadr method)
 377              last)))
 378
 379 (defun gnus-request-replace-article (article group buffer)
 380   (let ((func (car (gnus-group-name-to-method group))))
 381     (funcall (intern (format "%s-request-replace-article" func))
 382              article (gnus-group-real-name group) buffer)))
 383
 384 (defun gnus-request-associate-buffer (group)
 385   (let ((method (gnus-find-method-for-group group)))
 386     (funcall (gnus-get-function method 'request-associate-buffer)
 387              (gnus-group-real-name group))))
 388
 389 (defun gnus-request-restore-buffer (article group)
 390   "Request a new buffer restored to the state of ARTICLE."
 391   (let ((method (gnus-find-method-for-group group)))
 392     (funcall (gnus-get-function method 'request-restore-buffer)
 393              article (gnus-group-real-name group) (nth 1 method))))
 394
 395 (defun gnus-request-create-group (group &optional method args)
 396   (when (stringp method)
 397     (setq method (gnus-server-to-method method)))
 398   (let ((method (or method (gnus-find-method-for-group group))))
 399     (funcall (gnus-get-function method 'request-create-group)
 400              (gnus-group-real-name group) (nth 1 method) args)))
 401
 402 (defun gnus-request-delete-group (group &optional force)
 403   (let ((method (gnus-find-method-for-group group)))
 404     (funcall (gnus-get-function method 'request-delete-group)
 405              (gnus-group-real-name group) force (nth 1 method))))
 406
 407 (defun gnus-request-rename-group (group new-name)
 408   (let ((method (gnus-find-method-for-group group)))
 409     (funcall (gnus-get-function method 'request-rename-group)
 410              (gnus-group-real-name group)
 411              (gnus-group-real-name new-name) (nth 1 method))))
 412
 413 (defun gnus-close-backends ()
 414   ;; Send a close request to all backends that support such a request.
 415   (let ((methods gnus-valid-select-methods)
 416         (gnus-inhibit-demon t)
 417         func method)
 418     (while (setq method (pop methods))
 419       (when (fboundp (setq func (intern
 420                                  (concat (car method) "-request-close"))))
 421         (funcall func)))))
 422
 423 (defun gnus-asynchronous-p (method)
 424   (let ((func (gnus-get-function method 'asynchronous-p t)))
 425     (when (fboundp func)
 426       (funcall func))))
 427
 428 (defun gnus-remove-denial (method)
 429   (when (stringp method)
 430     (setq method (gnus-server-to-method method)))
 431   (let* ((elem (assoc method gnus-opened-servers))
 432          (status (cadr elem)))
 433     ;; If this hasn't been opened before, we add it to the list.
 434     (when (eq status 'denied)
 435       ;; Set the status of this server.
 436       (setcar (cdr elem) 'closed))))
 437
 438 (provide 'gnus-int)
 439
 440 ;;; gnus-int.el ends here