lisp/gnus/gnus-int.el

   1 ;;; gnus-int.el --- backend interface functions for Gnus
   2
   3 ;; Copyright (C) 1996-2011 Free Software Foundation, Inc.
   4
   5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   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 3 of the License, or
  13 ;; (at your option) 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
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;;; Code:
  26
  27 (eval-when-compile (require 'cl))
  28
  29 (require 'gnus)
  30 (require 'message)
  31 (require 'gnus-range)
  32
  33 (autoload 'gnus-run-hook-with-args "gnus-util")
  34 (autoload 'gnus-agent-expire "gnus-agent")
  35 (autoload 'gnus-agent-regenerate-group "gnus-agent")
  36 (autoload 'gnus-agent-read-servers-validate-native "gnus-agent")
  37 (autoload 'gnus-agent-possibly-synchronize-flags-server "gnus-agent")
  38
  39 (defcustom gnus-open-server-hook nil
  40   "Hook called just before opening connection to the news server."
  41   :group 'gnus-start
  42   :type 'hook)
  43
  44 (defcustom gnus-after-set-mark-hook nil
  45   "Hook called just after marks are set in a group."
  46   :group 'gnus-start
  47   :type 'hook)
  48
  49 (defcustom gnus-before-update-mark-hook nil
  50   "Hook called just before marks are updated in a group."
  51   :group 'gnus-start
  52   :type 'hook)
  53
  54 (defcustom gnus-server-unopen-status nil
  55   "The default status if the server is not able to open.
  56 If the server is covered by Gnus agent, the possible values are
  57 `denied', set the server denied; `offline', set the server offline;
  58 nil, ask user.  If the server is not covered by Gnus agent, set the
  59 server denied."
  60   :version "22.1"
  61   :group 'gnus-start
  62   :type '(choice (const :tag "Ask" nil)
  63                  (const :tag "Deny server" denied)
  64                  (const :tag "Unplug Agent" offline)))
  65
  66 (defvar gnus-internal-registry-spool-current-method nil
  67   "The current method, for the registry.")
  68
  69
  70 (defun gnus-server-opened (gnus-command-method)
  71   "Check whether a connection to GNUS-COMMAND-METHOD has been opened."
  72   (unless (eq (gnus-server-status gnus-command-method)
  73               'denied)
  74     (when (stringp gnus-command-method)
  75       (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
  76     (funcall (inline (gnus-get-function gnus-command-method 'server-opened))
  77              (nth 1 gnus-command-method))))
  78
  79 (defun gnus-status-message (gnus-command-method)
  80   "Return the status message from GNUS-COMMAND-METHOD.
  81 If GNUS-COMMAND-METHOD is a string, it is interpreted as a group
  82 name.  The method this group uses will be queried."
  83   (let ((gnus-command-method
  84          (if (stringp gnus-command-method)
  85              (gnus-find-method-for-group gnus-command-method)
  86            gnus-command-method)))
  87     (funcall (gnus-get-function gnus-command-method 'status-message)
  88              (nth 1 gnus-command-method))))
  89
  90 ;;;
  91 ;;; Server Communication
  92 ;;;
  93
  94 (defun gnus-start-news-server (&optional confirm)
  95   "Open a method for getting news.
  96 If CONFIRM is non-nil, the user will be asked for an NNTP server."
  97   (let (how)
  98     (if gnus-current-select-method
  99         ;; Stream is already opened.
 100         nil
 101       ;; Open NNTP server.
 102       (when confirm
 103         ;; Read server name with completion.
 104         (setq gnus-nntp-server
 105               (gnus-completing-read "NNTP server"
 106                                     (cons gnus-nntp-server
 107                                           gnus-secondary-servers)
 108                                     nil gnus-nntp-server)))
 109
 110       (when (and gnus-nntp-server
 111                  (stringp gnus-nntp-server)
 112                  (not (string= gnus-nntp-server "")))
 113         (setq gnus-select-method
 114               (cond ((or (string= gnus-nntp-server "")
 115                          (string= gnus-nntp-server "::"))
 116                      (list 'nnspool (system-name)))
 117                     ((string-match "^:" gnus-nntp-server)
 118                      (list 'nnmh gnus-nntp-server
 119                            (list 'nnmh-directory
 120                                  (file-name-as-directory
 121                                   (expand-file-name
 122                                    (substring gnus-nntp-server 1) "~/")))
 123                            (list 'nnmh-get-new-mail nil)))
 124                     (t
 125                      (list 'nntp gnus-nntp-server)))))
 126
 127       (setq how (car gnus-select-method))
 128       (cond
 129        ((eq how 'nnspool)
 130         (require 'nnspool)
 131         (gnus-message 5 "Looking up local news spool..."))
 132        ((eq how 'nnmh)
 133         (require 'nnmh)
 134         (gnus-message 5 "Looking up mh spool..."))
 135        (t
 136         (require 'nntp)))
 137       (setq gnus-current-select-method gnus-select-method)
 138       (gnus-run-hooks 'gnus-open-server-hook)
 139
 140       ;; Partially validate agent covered methods now that the
 141       ;; gnus-select-method is known.
 142
 143       (if gnus-agent
 144           ;; NOTE: This is here for one purpose only.  By validating
 145           ;; the current select method, it converts the old 5.10.3,
 146           ;; and earlier, format to the current format.  That enables
 147           ;; the agent code within gnus-open-server to function
 148           ;; correctly.
 149           (gnus-agent-read-servers-validate-native gnus-select-method))
 150
 151       (or
 152        ;; gnus-open-server-hook might have opened it
 153        (gnus-server-opened gnus-select-method)
 154        (gnus-open-server gnus-select-method)
 155        gnus-batch-mode
 156        (gnus-y-or-n-p
 157         (format
 158          "%s (%s) open error: '%s'.  Continue? "
 159          (car gnus-select-method) (cadr gnus-select-method)
 160          (gnus-status-message gnus-select-method)))
 161        (gnus-error 1 "Couldn't open server on %s"
 162                    (nth 1 gnus-select-method))))))
 163
 164 (defun gnus-check-group (group)
 165   "Try to make sure that the server where GROUP exists is alive."
 166   (let ((method (gnus-find-method-for-group group)))
 167     (or (gnus-server-opened method)
 168         (gnus-open-server method))))
 169
 170 (defun gnus-check-server (&optional method silent)
 171   "Check whether the connection to METHOD is down.
 172 If METHOD is nil, use `gnus-select-method'.
 173 If it is down, start it up (again)."
 174   (let ((method (or method gnus-select-method))
 175         result)
 176     ;; Transform virtual server names into select methods.
 177     (when (stringp method)
 178       (setq method (gnus-server-to-method method)))
 179     (if (gnus-server-opened method)
 180         ;; The stream is already opened.
 181         t
 182       ;; Open the server.
 183       (unless silent
 184         (gnus-message 5 "Opening %s server%s..." (car method)
 185                       (if (equal (nth 1 method) "") ""
 186                         (format " on %s" (nth 1 method)))))
 187       (gnus-run-hooks 'gnus-open-server-hook)
 188       (prog1
 189           (setq result (gnus-open-server method))
 190         (unless silent
 191           (gnus-message
 192            (if result 5 3)
 193            "Opening %s server%s...%s" (car method)
 194            (if (equal (nth 1 method) "") ""
 195              (format " on %s" (nth 1 method)))
 196            (if result
 197                "done"
 198              (format "failed: %s"
 199                      (nnheader-get-report-string (car method))))))))))
 200
 201 (defun gnus-get-function (method function &optional noerror)
 202   "Return a function symbol based on METHOD and FUNCTION."
 203   ;; Translate server names into methods.
 204   (unless method
 205     (error "Attempted use of a nil select method"))
 206   (when (stringp method)
 207     (setq method (gnus-server-to-method method)))
 208   ;; Check cache of constructed names.
 209   (let* ((method-sym (if gnus-agent
 210                          (inline (gnus-agent-get-function method))
 211                        (car method)))
 212          (method-fns (get method-sym 'gnus-method-functions))
 213          (func (let ((method-fnlist-elt (assq function method-fns)))
 214                  (unless method-fnlist-elt
 215                    (setq method-fnlist-elt
 216                          (cons function
 217                                (intern (format "%s-%s" method-sym function))))
 218                    (put method-sym 'gnus-method-functions
 219                         (cons method-fnlist-elt method-fns)))
 220                  (cdr method-fnlist-elt))))
 221     ;; Maybe complain if there is no function.
 222     (unless (fboundp func)
 223       (unless (car method)
 224         (error "Trying to require a method that doesn't exist"))
 225       (require (car method))
 226       (when (not (fboundp func))
 227         (if noerror
 228             (setq func nil)
 229           (error "No such function: %s" func))))
 230     func))
 231
 232 \f
 233 ;;;
 234 ;;; Interface functions to the backends.
 235 ;;;
 236
 237 (defun gnus-method-denied-p (method)
 238   (eq (nth 1 (assoc method gnus-opened-servers))
 239       'denied))
 240
 241 (defvar gnus-backend-trace t)
 242
 243 (defun gnus-open-server (gnus-command-method)
 244   "Open a connection to GNUS-COMMAND-METHOD."
 245   (when (stringp gnus-command-method)
 246     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 247   (when gnus-backend-trace
 248     (with-current-buffer (get-buffer-create "*gnus trace*")
 249       (buffer-disable-undo)
 250       (goto-char (point-max))
 251       (insert (format-time-string "%H:%M:%S")
 252               (format " %S\n" gnus-command-method))))
 253   (let ((elem (assoc gnus-command-method gnus-opened-servers))
 254         (server (gnus-method-to-server-name gnus-command-method)))
 255     ;; If this method was previously denied, we just return nil.
 256     (if (eq (nth 1 elem) 'denied)
 257         (progn
 258           (gnus-message 1 "Denied server %s" server)
 259           nil)
 260       ;; Open the server.
 261       (let* ((open-server-function
 262               (gnus-get-function gnus-command-method 'open-server))
 263              (result
 264               (condition-case err
 265                   (funcall open-server-function
 266                            (nth 1 gnus-command-method)
 267                            (nthcdr 2 gnus-command-method))
 268                 (error
 269                  (gnus-message 1 "Unable to open server %s due to: %s"
 270                                server (error-message-string err))
 271                  nil)
 272                 (quit
 273                  (if debug-on-quit
 274                      (debug "Quit")
 275                    (gnus-message 1 "Quit trying to open server %s" server))
 276                  nil)))
 277              open-offline)
 278         ;; If this hasn't been opened before, we add it to the list.
 279         (unless elem
 280           (setq elem (list gnus-command-method nil)
 281                 gnus-opened-servers (cons elem gnus-opened-servers)))
 282         ;; Set the status of this server.
 283         (setcar
 284          (cdr elem)
 285          (cond (result
 286                 (if (eq open-server-function #'nnagent-open-server)
 287                     ;; The agent's backend has a "special" status
 288                     'offline
 289                   'ok))
 290                ((and gnus-agent
 291                      (gnus-agent-method-p gnus-command-method))
 292                 (cond
 293                  (gnus-server-unopen-status
 294                   ;; Set the server's status to the unopen
 295                   ;; status.  If that status is offline,
 296                   ;; recurse to open the agent's backend.
 297                   (setq open-offline (eq gnus-server-unopen-status 'offline))
 298                   gnus-server-unopen-status)
 299                  ((not gnus-batch-mode)
 300                   (setq open-offline t)
 301                   'offline)
 302                  (t
 303                   ;; This agentized server was still denied
 304                   'denied)))
 305                (t
 306                 ;; This unagentized server must be denied
 307                 'denied)))
 308
 309         ;; NOTE: I MUST set the server's status to offline before this
 310         ;; recursive call as this status will drive the
 311         ;; gnus-get-function (called above) to return the agent's
 312         ;; backend.
 313         (if open-offline
 314             ;; Recursively open this offline server to perform the
 315             ;; open-server function of the agent's backend.
 316             (let ((gnus-server-unopen-status 'denied))
 317               ;; Bind gnus-server-unopen-status to avoid recursively
 318               ;; prompting with "go offline?".  This is only a concern
 319               ;; when the agent's backend fails to open the server.
 320               (gnus-open-server gnus-command-method))
 321           (when (and (eq (cadr elem) 'ok) gnus-agent
 322                      (gnus-agent-method-p gnus-command-method))
 323             (save-excursion
 324               (gnus-agent-possibly-synchronize-flags-server
 325                gnus-command-method)))
 326           result)))))
 327
 328 (defun gnus-close-server (gnus-command-method)
 329   "Close the connection to GNUS-COMMAND-METHOD."
 330   (when (stringp gnus-command-method)
 331     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 332   (funcall (gnus-get-function gnus-command-method 'close-server)
 333            (nth 1 gnus-command-method)))
 334
 335 (defun gnus-request-list (gnus-command-method)
 336   "Request the active file from GNUS-COMMAND-METHOD."
 337   (when (stringp gnus-command-method)
 338     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 339   (funcall (gnus-get-function gnus-command-method 'request-list)
 340            (nth 1 gnus-command-method)))
 341
 342 (defun gnus-finish-retrieve-group-infos (gnus-command-method infos data)
 343   "Read and update infos from GNUS-COMMAND-METHOD."
 344   (when (stringp gnus-command-method)
 345     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 346   (funcall (gnus-get-function gnus-command-method 'finish-retrieve-group-infos)
 347            (nth 1 gnus-command-method)
 348            infos data))
 349
 350 (defun gnus-retrieve-group-data-early (gnus-command-method infos)
 351   "Start early async retrival of data from GNUS-COMMAND-METHOD."
 352   (when (stringp gnus-command-method)
 353     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 354   (funcall (gnus-get-function gnus-command-method 'retrieve-group-data-early)
 355            (nth 1 gnus-command-method)
 356            infos))
 357
 358 (defun gnus-request-list-newsgroups (gnus-command-method)
 359   "Request the newsgroups file from GNUS-COMMAND-METHOD."
 360   (when (stringp gnus-command-method)
 361     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 362   (funcall (gnus-get-function gnus-command-method 'request-list-newsgroups)
 363            (nth 1 gnus-command-method)))
 364
 365 (defun gnus-request-newgroups (date gnus-command-method)
 366   "Request all new groups since DATE from GNUS-COMMAND-METHOD."
 367   (when (stringp gnus-command-method)
 368     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 369   (let ((func (gnus-get-function gnus-command-method 'request-newgroups t)))
 370     (when func
 371       (funcall func date (nth 1 gnus-command-method)))))
 372
 373 (defun gnus-request-regenerate (gnus-command-method)
 374   "Request a data generation from GNUS-COMMAND-METHOD."
 375   (when (stringp gnus-command-method)
 376     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 377   (funcall (gnus-get-function gnus-command-method 'request-regenerate)
 378            (nth 1 gnus-command-method)))
 379
 380 (defun gnus-request-compact-group (group)
 381   (let* ((method (gnus-find-method-for-group group))
 382          (gnus-command-method method)
 383          (result
 384           (funcall (gnus-get-function gnus-command-method
 385                                       'request-compact-group)
 386                    (gnus-group-real-name group)
 387                    (nth 1 gnus-command-method) t)))
 388     result))
 389
 390 (defun gnus-request-compact (gnus-command-method)
 391   "Request groups compaction  from GNUS-COMMAND-METHOD."
 392   (when (stringp gnus-command-method)
 393     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 394   (funcall (gnus-get-function gnus-command-method 'request-compact)
 395            (nth 1 gnus-command-method)))
 396
 397 (defun gnus-request-group (group &optional dont-check gnus-command-method info)
 398   "Request GROUP.  If DONT-CHECK, no information is required."
 399   (let ((gnus-command-method
 400          (or gnus-command-method (inline (gnus-find-method-for-group group)))))
 401     (when (stringp gnus-command-method)
 402       (setq gnus-command-method
 403             (inline (gnus-server-to-method gnus-command-method))))
 404     (funcall (inline (gnus-get-function gnus-command-method 'request-group))
 405              (gnus-group-real-name group) (nth 1 gnus-command-method)
 406              dont-check
 407              info)))
 408
 409 (defun gnus-list-active-group (group)
 410   "Request active information on GROUP."
 411   (let ((gnus-command-method (gnus-find-method-for-group group))
 412         (func 'list-active-group))
 413     (when (gnus-check-backend-function func group)
 414       (funcall (gnus-get-function gnus-command-method func)
 415                (gnus-group-real-name group) (nth 1 gnus-command-method)))))
 416
 417 (defun gnus-request-group-description (group)
 418   "Request a description of GROUP."
 419   (let ((gnus-command-method (gnus-find-method-for-group group))
 420         (func 'request-group-description))
 421     (when (gnus-check-backend-function func group)
 422       (funcall (gnus-get-function gnus-command-method func)
 423                (gnus-group-real-name group) (nth 1 gnus-command-method)))))
 424
 425 (defun gnus-request-group-articles (group)
 426   "Request a list of existing articles in GROUP."
 427   (let ((gnus-command-method (gnus-find-method-for-group group))
 428         (func 'request-group-articles))
 429     (when (gnus-check-backend-function func group)
 430       (funcall (gnus-get-function gnus-command-method func)
 431                (gnus-group-real-name group) (nth 1 gnus-command-method)))))
 432
 433 (defun gnus-close-group (group)
 434   "Request the GROUP be closed."
 435   (let ((gnus-command-method (inline (gnus-find-method-for-group group))))
 436     (funcall (gnus-get-function gnus-command-method 'close-group)
 437              (gnus-group-real-name group) (nth 1 gnus-command-method))))
 438
 439 (defun gnus-retrieve-headers (articles group &optional fetch-old)
 440   "Request headers for ARTICLES in GROUP.
 441 If FETCH-OLD, retrieve all headers (or some subset thereof) in the group."
 442   (let ((gnus-command-method (gnus-find-method-for-group group)))
 443     (cond
 444      ((and gnus-use-cache (numberp (car articles)))
 445       (gnus-cache-retrieve-headers articles group fetch-old))
 446      ((and gnus-agent (gnus-online gnus-command-method)
 447            (gnus-agent-method-p gnus-command-method))
 448       (gnus-agent-retrieve-headers articles group fetch-old))
 449      (t
 450       (funcall (gnus-get-function gnus-command-method 'retrieve-headers)
 451                articles (gnus-group-real-name group)
 452                (nth 1 gnus-command-method) fetch-old)))))
 453
 454 (defun gnus-retrieve-articles (articles group)
 455   "Request ARTICLES in GROUP."
 456   (let ((gnus-command-method (gnus-find-method-for-group group)))
 457     (funcall (gnus-get-function gnus-command-method 'retrieve-articles)
 458              articles (gnus-group-real-name group)
 459              (nth 1 gnus-command-method))))
 460
 461 (defun gnus-retrieve-groups (groups gnus-command-method)
 462   "Request active information on GROUPS from GNUS-COMMAND-METHOD."
 463   (when (stringp gnus-command-method)
 464     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 465   (funcall (gnus-get-function gnus-command-method 'retrieve-groups)
 466            groups (nth 1 gnus-command-method)))
 467
 468 (defun gnus-request-type (group &optional article)
 469   "Return the type (`post' or `mail') of GROUP (and ARTICLE)."
 470   (let ((gnus-command-method (gnus-find-method-for-group group)))
 471     (if (not (gnus-check-backend-function
 472               'request-type (car gnus-command-method)))
 473         'unknown
 474       (funcall (gnus-get-function gnus-command-method 'request-type)
 475                (gnus-group-real-name group) article))))
 476
 477 (defun gnus-request-update-group-status (group status)
 478   "Change the status of a group.
 479 Valid statuses include `subscribe' and `unsubscribe'."
 480   (let ((gnus-command-method (gnus-find-method-for-group group)))
 481     (if (not (gnus-check-backend-function
 482               'request-update-group-status (car gnus-command-method)))
 483         nil
 484       (funcall
 485        (gnus-get-function gnus-command-method 'request-update-group-status)
 486        (gnus-group-real-name group) status
 487        (nth 1 gnus-command-method)))))
 488
 489 (defun gnus-request-set-mark (group action)
 490   "Set marks on articles in the back end."
 491   (let ((gnus-command-method (gnus-find-method-for-group group)))
 492     (if (not (gnus-check-backend-function
 493               'request-set-mark (car gnus-command-method)))
 494         action
 495       (funcall (gnus-get-function gnus-command-method 'request-set-mark)
 496                (gnus-group-real-name group) action
 497                (nth 1 gnus-command-method))
 498       (gnus-run-hook-with-args gnus-after-set-mark-hook group action))))
 499
 500 (defun gnus-request-update-mark (group article mark)
 501   "Allow the back end to change the mark the user tries to put on an article."
 502   (let ((gnus-command-method (gnus-find-method-for-group group)))
 503     (if (not (gnus-check-backend-function
 504               'request-update-mark (car gnus-command-method)))
 505         mark
 506       (gnus-run-hook-with-args gnus-before-update-mark-hook group article mark)
 507       (funcall (gnus-get-function gnus-command-method 'request-update-mark)
 508                (gnus-group-real-name group) article mark))))
 509
 510 (defun gnus-request-article (article group &optional buffer)
 511   "Request the ARTICLE in GROUP.
 512 ARTICLE can either be an article number or an article Message-ID.
 513 If BUFFER, insert the article in that group."
 514   (let ((gnus-command-method (gnus-find-method-for-group group)))
 515     (funcall (gnus-get-function gnus-command-method 'request-article)
 516              article (gnus-group-real-name group)
 517              (nth 1 gnus-command-method) buffer)))
 518
 519 (defun gnus-request-thread (header group)
 520   "Request the headers in the thread containing the article specified by HEADER."
 521   (let ((gnus-command-method (gnus-find-method-for-group group)))
 522     (funcall (gnus-get-function gnus-command-method 'request-thread)
 523              header
 524              (gnus-group-real-name group))))
 525
 526 (defun gnus-warp-to-article ()
 527   "Warps from an article in a virtual group to the article in its
 528 real group. Does nothing on a real group."
 529   (interactive)
 530   (let ((gnus-command-method
 531          (gnus-find-method-for-group gnus-newsgroup-name)))
 532     (when (gnus-check-backend-function
 533            'warp-to-article (car gnus-command-method))
 534       (funcall (gnus-get-function gnus-command-method 'warp-to-article)))))
 535
 536 (defun gnus-request-head (article group)
 537   "Request the head of ARTICLE in GROUP."
 538   (let* ((gnus-command-method (gnus-find-method-for-group group))
 539          (head (gnus-get-function gnus-command-method 'request-head t))
 540          res clean-up)
 541     (cond
 542      ;; Check the cache.
 543      ((and gnus-use-cache
 544            (numberp article)
 545            (gnus-cache-request-article article group))
 546       (setq res (cons group article)
 547             clean-up t))
 548      ;; Check the agent cache.
 549      ((gnus-agent-request-article article group)
 550       (setq res (cons group article)
 551             clean-up t))
 552      ;; Use `head' function.
 553      ((fboundp head)
 554       (setq res (funcall head article (gnus-group-real-name group)
 555                          (nth 1 gnus-command-method))))
 556      ;; Use `article' function.
 557      (t
 558       (setq res (gnus-request-article article group)
 559             clean-up t)))
 560     (when clean-up
 561       (with-current-buffer nntp-server-buffer
 562         (goto-char (point-min))
 563         (when (search-forward "\n\n" nil t)
 564           (delete-region (1- (point)) (point-max)))
 565         (nnheader-fold-continuation-lines)))
 566     res))
 567
 568 (defun gnus-request-body (article group)
 569   "Request the body of ARTICLE in GROUP."
 570   (let* ((gnus-command-method (gnus-find-method-for-group group))
 571          (head (gnus-get-function gnus-command-method 'request-body t))
 572          res clean-up)
 573     (cond
 574      ;; Check the cache.
 575      ((and gnus-use-cache
 576            (numberp article)
 577            (gnus-cache-request-article article group))
 578       (setq res (cons group article)
 579             clean-up t))
 580      ;; Check the agent cache.
 581      ((gnus-agent-request-article article group)
 582       (setq res (cons group article)
 583             clean-up t))
 584      ;; Use `head' function.
 585      ((fboundp head)
 586       (setq res (funcall head article (gnus-group-real-name group)
 587                          (nth 1 gnus-command-method))))
 588      ;; Use `article' function.
 589      (t
 590       (setq res (gnus-request-article article group)
 591             clean-up t)))
 592     (when clean-up
 593       (with-current-buffer nntp-server-buffer
 594         (goto-char (point-min))
 595         (when (search-forward "\n\n" nil t)
 596           (delete-region (point-min) (1- (point))))))
 597     res))
 598
 599 (defun gnus-request-post (gnus-command-method)
 600   "Post the current buffer using GNUS-COMMAND-METHOD."
 601   (when (stringp gnus-command-method)
 602     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 603   (funcall (gnus-get-function gnus-command-method 'request-post)
 604            (nth 1 gnus-command-method)))
 605
 606 (defun gnus-request-expunge-group (group gnus-command-method)
 607   "Expunge GROUP, which is removing articles that have been marked as deleted."
 608   (when (stringp gnus-command-method)
 609     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 610   (funcall (gnus-get-function gnus-command-method 'request-expunge-group)
 611            (gnus-group-real-name group)
 612            (nth 1 gnus-command-method)))
 613
 614 (defun gnus-request-scan (group gnus-command-method)
 615   "Request a SCAN being performed in GROUP from GNUS-COMMAND-METHOD.
 616 If GROUP is nil, all groups on GNUS-COMMAND-METHOD are scanned."
 617   (let ((gnus-command-method
 618          (if group (gnus-find-method-for-group group) gnus-command-method))
 619         (gnus-inhibit-demon t)
 620         (mail-source-plugged gnus-plugged))
 621     (when (or gnus-plugged
 622               (not (gnus-agent-method-p gnus-command-method)))
 623       (setq gnus-internal-registry-spool-current-method gnus-command-method)
 624       (funcall (gnus-get-function gnus-command-method 'request-scan)
 625                (and group (gnus-group-real-name group))
 626                (nth 1 gnus-command-method)))))
 627
 628 (defun gnus-request-update-info (info gnus-command-method)
 629   (when (gnus-check-backend-function
 630          'request-update-info (car gnus-command-method))
 631     (when (stringp gnus-command-method)
 632       (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 633     (funcall (gnus-get-function gnus-command-method 'request-update-info)
 634              (gnus-group-real-name (gnus-info-group info)) info
 635              (nth 1 gnus-command-method))))
 636
 637 (defsubst gnus-request-marks (info gnus-command-method)
 638   "Request that GNUS-COMMAND-METHOD update INFO."
 639   (when (stringp gnus-command-method)
 640     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 641   (when (gnus-check-backend-function
 642          'request-marks (car gnus-command-method))
 643     (let ((group (gnus-info-group info)))
 644       (and (funcall (gnus-get-function gnus-command-method 'request-marks)
 645                     (gnus-group-real-name group)
 646                     info (nth 1 gnus-command-method))
 647            ;; If the minimum article number is greater than 1, then all
 648            ;; smaller article numbers are known not to exist; we'll
 649            ;; artificially add those to the 'read range.
 650            (let* ((active (gnus-active group))
 651                   (min (car active)))
 652              (when (> min 1)
 653                (let* ((range (if (= min 2) 1 (cons 1 (1- min))))
 654                       (read (gnus-info-read info))
 655                       (new-read (gnus-range-add read (list range))))
 656                  (gnus-info-set-read info new-read)))
 657              info)))))
 658
 659 (defun gnus-request-expire-articles (articles group &optional force)
 660   (let* ((gnus-command-method (gnus-find-method-for-group group))
 661          (gnus-inhibit-demon t)
 662          (not-deleted
 663           (funcall
 664            (gnus-get-function gnus-command-method 'request-expire-articles)
 665            articles (gnus-group-real-name group) (nth 1 gnus-command-method)
 666            force)))
 667     (when (and gnus-agent
 668                (gnus-agent-method-p gnus-command-method))
 669       (let ((expired-articles (gnus-sorted-difference articles not-deleted)))
 670         (when expired-articles
 671           (gnus-agent-expire expired-articles group 'force))))
 672     not-deleted))
 673
 674 (defun gnus-request-move-article (article group server accept-function
 675                                           &optional last move-is-internal)
 676   (let* ((gnus-command-method (gnus-find-method-for-group group))
 677          (result (funcall (gnus-get-function gnus-command-method
 678                                              'request-move-article)
 679                           article (gnus-group-real-name group)
 680                           (nth 1 gnus-command-method) accept-function
 681                           last move-is-internal)))
 682     (when (and result gnus-agent
 683                (gnus-agent-method-p gnus-command-method))
 684       (gnus-agent-unfetch-articles group (list article)))
 685     result))
 686
 687 (defun gnus-request-accept-article (group &optional gnus-command-method last
 688                                           no-encode)
 689   ;; Make sure there's a newline at the end of the article.
 690   (when (stringp gnus-command-method)
 691     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 692   (when (and (not gnus-command-method)
 693              (stringp group))
 694     (setq gnus-command-method (or (gnus-find-method-for-group group)
 695                                   (gnus-group-name-to-method group))))
 696   (goto-char (point-max))
 697   (unless (bolp)
 698     (insert "\n"))
 699   (unless no-encode
 700     (let ((message-options message-options))
 701       (message-options-set-recipient)
 702       (save-restriction
 703         (message-narrow-to-head)
 704         (let ((mail-parse-charset message-default-charset))
 705           (mail-encode-encoded-word-buffer)))
 706       (message-encode-message-body)))
 707   (let ((gnus-command-method (or gnus-command-method
 708                                  (gnus-find-method-for-group group)))
 709         (result
 710          (funcall
 711           (gnus-get-function gnus-command-method 'request-accept-article)
 712           (if (stringp group) (gnus-group-real-name group) group)
 713           (cadr gnus-command-method)
 714           last)))
 715     (when (and gnus-agent
 716                (gnus-agent-method-p gnus-command-method)
 717                (cdr result))
 718       (gnus-agent-regenerate-group group (list (cdr result))))
 719     result))
 720
 721 (defun gnus-request-replace-article (article group buffer &optional no-encode)
 722   (unless no-encode
 723     (let ((message-options message-options))
 724       (message-options-set-recipient)
 725       (save-restriction
 726         (message-narrow-to-head)
 727         (let ((mail-parse-charset message-default-charset))
 728           (mail-encode-encoded-word-buffer)))
 729       (message-encode-message-body)))
 730   (let* ((func (car (gnus-group-name-to-method group)))
 731          (result (funcall (intern (format "%s-request-replace-article" func))
 732                           article (gnus-group-real-name group) buffer)))
 733     (when (and gnus-agent (gnus-agent-method-p gnus-command-method))
 734       (gnus-agent-regenerate-group group (list article)))
 735     result))
 736
 737 (defun gnus-request-associate-buffer (group)
 738   (let ((gnus-command-method (gnus-find-method-for-group group)))
 739     (funcall (gnus-get-function gnus-command-method 'request-associate-buffer)
 740              (gnus-group-real-name group))))
 741
 742 (defun gnus-request-restore-buffer (article group)
 743   "Request a new buffer restored to the state of ARTICLE."
 744   (let ((gnus-command-method (gnus-find-method-for-group group)))
 745     (funcall (gnus-get-function gnus-command-method 'request-restore-buffer)
 746              article (gnus-group-real-name group)
 747              (nth 1 gnus-command-method))))
 748
 749 (defun gnus-request-create-group (group &optional gnus-command-method args)
 750   (when (stringp gnus-command-method)
 751     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 752   (let ((gnus-command-method
 753          (or gnus-command-method (gnus-find-method-for-group group))))
 754     (funcall (gnus-get-function gnus-command-method 'request-create-group)
 755              (gnus-group-real-name group) (nth 1 gnus-command-method) args)))
 756
 757 (defun gnus-request-delete-group (group &optional force)
 758   (let* ((gnus-command-method (gnus-find-method-for-group group))
 759          (result
 760           (funcall (gnus-get-function gnus-command-method 'request-delete-group)
 761                    (gnus-group-real-name group) force (nth 1 gnus-command-method))))
 762     (when result
 763       (gnus-cache-delete-group group)
 764       (gnus-agent-delete-group group))
 765     result))
 766
 767 (defun gnus-request-rename-group (group new-name)
 768   (let* ((gnus-command-method (gnus-find-method-for-group group))
 769          (result
 770           (funcall (gnus-get-function gnus-command-method 'request-rename-group)
 771                    (gnus-group-real-name group)
 772                    (gnus-group-real-name new-name) (nth 1 gnus-command-method))))
 773     (when result
 774       (gnus-cache-rename-group group new-name)
 775       (gnus-agent-rename-group group new-name))
 776     result))
 777
 778 (defun gnus-close-backends ()
 779   ;; Send a close request to all backends that support such a request.
 780   (let ((methods gnus-valid-select-methods)
 781         (gnus-inhibit-demon t)
 782         func gnus-command-method)
 783     (while (setq gnus-command-method (pop methods))
 784       (when (fboundp (setq func (intern
 785                                  (concat (car gnus-command-method)
 786                                          "-request-close"))))
 787         (funcall func)))))
 788
 789 (defun gnus-asynchronous-p (gnus-command-method)
 790   (let ((func (gnus-get-function gnus-command-method 'asynchronous-p t)))
 791     (when (fboundp func)
 792       (funcall func))))
 793
 794 (defun gnus-remove-denial (gnus-command-method)
 795   (when (stringp gnus-command-method)
 796     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 797   (let* ((elem (assoc gnus-command-method gnus-opened-servers))
 798          (status (cadr elem)))
 799     ;; If this hasn't been opened before, we add it to the list.
 800     (when (eq status 'denied)
 801       ;; Set the status of this server.
 802       (setcar (cdr elem) 'closed))))
 803
 804 (provide 'gnus-int)
 805
 806 ;;; gnus-int.el ends here