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 (defcustom gnus-nntp-server nil
  67   "The name of the host running the NNTP server."
  68   :group 'gnus-server
  69   :type '(choice (const :tag "disable" nil)
  70                  string))
  71 (make-obsolete-variable 'gnus-nntp-server 'gnus-select-method "24.1")
  72
  73 (defvar gnus-internal-registry-spool-current-method nil
  74   "The current method, for the registry.")
  75
  76
  77 (defun gnus-server-opened (gnus-command-method)
  78   "Check whether a connection to GNUS-COMMAND-METHOD has been opened."
  79   (unless (eq (gnus-server-status gnus-command-method)
  80               'denied)
  81     (when (stringp gnus-command-method)
  82       (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
  83     (funcall (inline (gnus-get-function gnus-command-method 'server-opened))
  84              (nth 1 gnus-command-method))))
  85
  86 (defun gnus-status-message (gnus-command-method)
  87   "Return the status message from GNUS-COMMAND-METHOD.
  88 If GNUS-COMMAND-METHOD is a string, it is interpreted as a group
  89 name.  The method this group uses will be queried."
  90   (let ((gnus-command-method
  91          (if (stringp gnus-command-method)
  92              (gnus-find-method-for-group gnus-command-method)
  93            gnus-command-method)))
  94     (funcall (gnus-get-function gnus-command-method 'status-message)
  95              (nth 1 gnus-command-method))))
  96
  97 ;;;
  98 ;;; Server Communication
  99 ;;;
 100
 101 (defun gnus-start-news-server (&optional confirm)
 102   "Open a method for getting news.
 103 If CONFIRM is non-nil, the user will be asked for an NNTP server."
 104   (let (how)
 105     (if gnus-current-select-method
 106         ;; Stream is already opened.
 107         nil
 108       ;; Open NNTP server.
 109       (when confirm
 110         ;; Read server name with completion.
 111         (setq gnus-nntp-server
 112               (gnus-completing-read "NNTP server"
 113                                     (cons gnus-nntp-server
 114                                           gnus-secondary-servers)
 115                                     nil gnus-nntp-server)))
 116
 117       (when (and gnus-nntp-server
 118                  (stringp gnus-nntp-server)
 119                  (not (string= gnus-nntp-server "")))
 120         (setq gnus-select-method
 121               (cond ((or (string= gnus-nntp-server "")
 122                          (string= gnus-nntp-server "::"))
 123                      (list 'nnspool (system-name)))
 124                     ((string-match "^:" gnus-nntp-server)
 125                      (list 'nnmh gnus-nntp-server
 126                            (list 'nnmh-directory
 127                                  (file-name-as-directory
 128                                   (expand-file-name
 129                                    (substring gnus-nntp-server 1) "~/")))
 130                            (list 'nnmh-get-new-mail nil)))
 131                     (t
 132                      (list 'nntp gnus-nntp-server)))))
 133
 134       (setq how (car gnus-select-method))
 135       (cond
 136        ((eq how 'nnspool)
 137         (require 'nnspool)
 138         (gnus-message 5 "Looking up local news spool..."))
 139        ((eq how 'nnmh)
 140         (require 'nnmh)
 141         (gnus-message 5 "Looking up mh spool..."))
 142        (t
 143         (require 'nntp)))
 144       (setq gnus-current-select-method gnus-select-method)
 145       (gnus-run-hooks 'gnus-open-server-hook)
 146
 147       ;; Partially validate agent covered methods now that the
 148       ;; gnus-select-method is known.
 149
 150       (if gnus-agent
 151           ;; NOTE: This is here for one purpose only.  By validating
 152           ;; the current select method, it converts the old 5.10.3,
 153           ;; and earlier, format to the current format.  That enables
 154           ;; the agent code within gnus-open-server to function
 155           ;; correctly.
 156           (gnus-agent-read-servers-validate-native gnus-select-method))
 157
 158       (or
 159        ;; gnus-open-server-hook might have opened it
 160        (gnus-server-opened gnus-select-method)
 161        (gnus-open-server gnus-select-method)
 162        gnus-batch-mode
 163        (gnus-y-or-n-p
 164         (format
 165          "%s (%s) open error: '%s'.  Continue? "
 166          (car gnus-select-method) (cadr gnus-select-method)
 167          (gnus-status-message gnus-select-method)))
 168        (gnus-error 1 "Couldn't open server on %s"
 169                    (nth 1 gnus-select-method))))))
 170
 171 (defun gnus-check-group (group)
 172   "Try to make sure that the server where GROUP exists is alive."
 173   (let ((method (gnus-find-method-for-group group)))
 174     (or (gnus-server-opened method)
 175         (gnus-open-server method))))
 176
 177 (defun gnus-check-server (&optional method silent)
 178   "Check whether the connection to METHOD is down.
 179 If METHOD is nil, use `gnus-select-method'.
 180 If it is down, start it up (again)."
 181   (let ((method (or method gnus-select-method))
 182         result)
 183     ;; Transform virtual server names into select methods.
 184     (when (stringp method)
 185       (setq method (gnus-server-to-method method)))
 186     (if (gnus-server-opened method)
 187         ;; The stream is already opened.
 188         t
 189       ;; Open the server.
 190       (unless silent
 191         (gnus-message 5 "Opening %s server%s..." (car method)
 192                       (if (equal (nth 1 method) "") ""
 193                         (format " on %s" (nth 1 method)))))
 194       (gnus-run-hooks 'gnus-open-server-hook)
 195       (prog1
 196           (setq result (gnus-open-server method))
 197         (unless silent
 198           (gnus-message
 199            (if result 5 3)
 200            "Opening %s server%s...%s" (car method)
 201            (if (equal (nth 1 method) "") ""
 202              (format " on %s" (nth 1 method)))
 203            (if result
 204                "done"
 205              (format "failed: %s"
 206                      (nnheader-get-report-string (car method))))))))))
 207
 208 (defun gnus-get-function (method function &optional noerror)
 209   "Return a function symbol based on METHOD and FUNCTION."
 210   ;; Translate server names into methods.
 211   (unless method
 212     (error "Attempted use of a nil select method"))
 213   (when (stringp method)
 214     (setq method (gnus-server-to-method method)))
 215   ;; Check cache of constructed names.
 216   (let* ((method-sym (if gnus-agent
 217                          (inline (gnus-agent-get-function method))
 218                        (car method)))
 219          (method-fns (get method-sym 'gnus-method-functions))
 220          (func (let ((method-fnlist-elt (assq function method-fns)))
 221                  (unless method-fnlist-elt
 222                    (setq method-fnlist-elt
 223                          (cons function
 224                                (intern (format "%s-%s" method-sym function))))
 225                    (put method-sym 'gnus-method-functions
 226                         (cons method-fnlist-elt method-fns)))
 227                  (cdr method-fnlist-elt))))
 228     ;; Maybe complain if there is no function.
 229     (unless (fboundp func)
 230       (unless (car method)
 231         (error "Trying to require a method that doesn't exist"))
 232       (require (car method))
 233       (when (not (fboundp func))
 234         (if noerror
 235             (setq func nil)
 236           (error "No such function: %s" func))))
 237     func))
 238
 239 \f
 240 ;;;
 241 ;;; Interface functions to the backends.
 242 ;;;
 243
 244 (defun gnus-method-denied-p (method)
 245   (eq (nth 1 (assoc method gnus-opened-servers))
 246       'denied))
 247
 248 (defvar gnus-backend-trace t)
 249
 250 (defun gnus-open-server (gnus-command-method)
 251   "Open a connection to GNUS-COMMAND-METHOD."
 252   (when (stringp gnus-command-method)
 253     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 254   (when gnus-backend-trace
 255     (with-current-buffer (get-buffer-create "*gnus trace*")
 256       (buffer-disable-undo)
 257       (goto-char (point-max))
 258       (insert (format-time-string "%H:%M:%S")
 259               (format " %S\n" gnus-command-method))))
 260   (let ((elem (assoc gnus-command-method gnus-opened-servers))
 261         (server (gnus-method-to-server-name gnus-command-method)))
 262     ;; If this method was previously denied, we just return nil.
 263     (if (eq (nth 1 elem) 'denied)
 264         (progn
 265           (gnus-message
 266            1 "Server %s previously determined to be down; not retrying" server)
 267           nil)
 268       ;; Open the server.
 269       (let* ((open-server-function
 270               (gnus-get-function gnus-command-method 'open-server))
 271              (result
 272               (condition-case err
 273                   (funcall open-server-function
 274                            (nth 1 gnus-command-method)
 275                            (nthcdr 2 gnus-command-method))
 276                 (error
 277                  (gnus-message 1 "Unable to open server %s due to: %s"
 278                                server (error-message-string err))
 279                  nil)
 280                 (quit
 281                  (if debug-on-quit
 282                      (debug "Quit")
 283                    (gnus-message 1 "Quit trying to open server %s" server))
 284                  nil)))
 285              open-offline)
 286         ;; If this hasn't been opened before, we add it to the list.
 287         (unless elem
 288           (setq elem (list gnus-command-method nil)
 289                 gnus-opened-servers (cons elem gnus-opened-servers)))
 290         ;; Set the status of this server.
 291         (setcar
 292          (cdr elem)
 293          (cond (result
 294                 (if (eq open-server-function #'nnagent-open-server)
 295                     ;; The agent's backend has a "special" status
 296                     'offline
 297                   'ok))
 298                ((and gnus-agent
 299                      (gnus-agent-method-p gnus-command-method))
 300                 (cond
 301                  (gnus-server-unopen-status
 302                   ;; Set the server's status to the unopen
 303                   ;; status.  If that status is offline,
 304                   ;; recurse to open the agent's backend.
 305                   (setq open-offline (eq gnus-server-unopen-status 'offline))
 306                   gnus-server-unopen-status)
 307                  ((not gnus-batch-mode)
 308                   (setq open-offline t)
 309                   'offline)
 310                  (t
 311                   ;; This agentized server was still denied
 312                   'denied)))
 313                (t
 314                 ;; This unagentized server must be denied
 315                 'denied)))
 316
 317         ;; NOTE: I MUST set the server's status to offline before this
 318         ;; recursive call as this status will drive the
 319         ;; gnus-get-function (called above) to return the agent's
 320         ;; backend.
 321         (if open-offline
 322             ;; Recursively open this offline server to perform the
 323             ;; open-server function of the agent's backend.
 324             (let ((gnus-server-unopen-status 'denied))
 325               ;; Bind gnus-server-unopen-status to avoid recursively
 326               ;; prompting with "go offline?".  This is only a concern
 327               ;; when the agent's backend fails to open the server.
 328               (gnus-open-server gnus-command-method))
 329           (when (and (eq (cadr elem) 'ok) gnus-agent
 330                      (gnus-agent-method-p gnus-command-method))
 331             (save-excursion
 332               (gnus-agent-possibly-synchronize-flags-server
 333                gnus-command-method)))
 334           result)))))
 335
 336 (defun gnus-close-server (gnus-command-method)
 337   "Close the connection to GNUS-COMMAND-METHOD."
 338   (when (stringp gnus-command-method)
 339     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 340   (funcall (gnus-get-function gnus-command-method 'close-server)
 341            (nth 1 gnus-command-method)))
 342
 343 (defun gnus-request-list (gnus-command-method)
 344   "Request the active file from GNUS-COMMAND-METHOD."
 345   (when (stringp gnus-command-method)
 346     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 347   (funcall (gnus-get-function gnus-command-method 'request-list)
 348            (nth 1 gnus-command-method)))
 349
 350 (defun gnus-finish-retrieve-group-infos (gnus-command-method infos data)
 351   "Read and update infos 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 'finish-retrieve-group-infos)
 355            (nth 1 gnus-command-method)
 356            infos data))
 357
 358 (defun gnus-retrieve-group-data-early (gnus-command-method infos)
 359   "Start early async retrieval of data 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 'retrieve-group-data-early)
 363            (nth 1 gnus-command-method)
 364            infos))
 365
 366 (defun gnus-request-list-newsgroups (gnus-command-method)
 367   "Request the newsgroups file from GNUS-COMMAND-METHOD."
 368   (when (stringp gnus-command-method)
 369     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 370   (funcall (gnus-get-function gnus-command-method 'request-list-newsgroups)
 371            (nth 1 gnus-command-method)))
 372
 373 (defun gnus-request-newgroups (date gnus-command-method)
 374   "Request all new groups since DATE from GNUS-COMMAND-METHOD."
 375   (when (stringp gnus-command-method)
 376     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 377   (let ((func (gnus-get-function gnus-command-method 'request-newgroups t)))
 378     (when func
 379       (funcall func date (nth 1 gnus-command-method)))))
 380
 381 (defun gnus-request-regenerate (gnus-command-method)
 382   "Request a data generation from GNUS-COMMAND-METHOD."
 383   (when (stringp gnus-command-method)
 384     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 385   (funcall (gnus-get-function gnus-command-method 'request-regenerate)
 386            (nth 1 gnus-command-method)))
 387
 388 (defun gnus-request-compact-group (group)
 389   (let* ((method (gnus-find-method-for-group group))
 390          (gnus-command-method method)
 391          (result
 392           (funcall (gnus-get-function gnus-command-method
 393                                       'request-compact-group)
 394                    (gnus-group-real-name group)
 395                    (nth 1 gnus-command-method) t)))
 396     result))
 397
 398 (defun gnus-request-compact (gnus-command-method)
 399   "Request groups compaction  from GNUS-COMMAND-METHOD."
 400   (when (stringp gnus-command-method)
 401     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 402   (funcall (gnus-get-function gnus-command-method 'request-compact)
 403            (nth 1 gnus-command-method)))
 404
 405 (defun gnus-request-group (group &optional dont-check gnus-command-method info)
 406   "Request GROUP.  If DONT-CHECK, no information is required."
 407   (let ((gnus-command-method
 408          (or gnus-command-method (inline (gnus-find-method-for-group group)))))
 409     (when (stringp gnus-command-method)
 410       (setq gnus-command-method
 411             (inline (gnus-server-to-method gnus-command-method))))
 412     (funcall (inline (gnus-get-function gnus-command-method 'request-group))
 413              (gnus-group-real-name group) (nth 1 gnus-command-method)
 414              dont-check
 415              info)))
 416
 417 (defun gnus-list-active-group (group)
 418   "Request active information on GROUP."
 419   (let ((gnus-command-method (gnus-find-method-for-group group))
 420         (func 'list-active-group))
 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-description (group)
 426   "Request a description of GROUP."
 427   (let ((gnus-command-method (gnus-find-method-for-group group))
 428         (func 'request-group-description))
 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-request-group-articles (group)
 434   "Request a list of existing articles in GROUP."
 435   (let ((gnus-command-method (gnus-find-method-for-group group))
 436         (func 'request-group-articles))
 437     (when (gnus-check-backend-function func group)
 438       (funcall (gnus-get-function gnus-command-method func)
 439                (gnus-group-real-name group) (nth 1 gnus-command-method)))))
 440
 441 (defun gnus-close-group (group)
 442   "Request the GROUP be closed."
 443   (let ((gnus-command-method (inline (gnus-find-method-for-group group))))
 444     (funcall (gnus-get-function gnus-command-method 'close-group)
 445              (gnus-group-real-name group) (nth 1 gnus-command-method))))
 446
 447 (defun gnus-retrieve-headers (articles group &optional fetch-old)
 448   "Request headers for ARTICLES in GROUP.
 449 If FETCH-OLD, retrieve all headers (or some subset thereof) in the group."
 450   (let ((gnus-command-method (gnus-find-method-for-group group)))
 451     (cond
 452      ((and gnus-use-cache (numberp (car articles)))
 453       (gnus-cache-retrieve-headers articles group fetch-old))
 454      ((and gnus-agent (gnus-online gnus-command-method)
 455            (gnus-agent-method-p gnus-command-method))
 456       (gnus-agent-retrieve-headers articles group fetch-old))
 457      (t
 458       (funcall (gnus-get-function gnus-command-method 'retrieve-headers)
 459                articles (gnus-group-real-name group)
 460                (nth 1 gnus-command-method) fetch-old)))))
 461
 462 (defun gnus-retrieve-articles (articles group)
 463   "Request ARTICLES in GROUP."
 464   (let ((gnus-command-method (gnus-find-method-for-group group)))
 465     (funcall (gnus-get-function gnus-command-method 'retrieve-articles)
 466              articles (gnus-group-real-name group)
 467              (nth 1 gnus-command-method))))
 468
 469 (defun gnus-retrieve-groups (groups gnus-command-method)
 470   "Request active information on GROUPS from GNUS-COMMAND-METHOD."
 471   (when (stringp gnus-command-method)
 472     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 473   (funcall (gnus-get-function gnus-command-method 'retrieve-groups)
 474            groups (nth 1 gnus-command-method)))
 475
 476 (defun gnus-request-type (group &optional article)
 477   "Return the type (`post' or `mail') of GROUP (and ARTICLE)."
 478   (let ((gnus-command-method (gnus-find-method-for-group group)))
 479     (if (not (gnus-check-backend-function
 480               'request-type (car gnus-command-method)))
 481         'unknown
 482       (funcall (gnus-get-function gnus-command-method 'request-type)
 483                (gnus-group-real-name group) article))))
 484
 485 (defun gnus-request-update-group-status (group status)
 486   "Change the status of a group.
 487 Valid statuses include `subscribe' and `unsubscribe'."
 488   (let ((gnus-command-method (gnus-find-method-for-group group)))
 489     (if (not (gnus-check-backend-function
 490               'request-update-group-status (car gnus-command-method)))
 491         nil
 492       (funcall
 493        (gnus-get-function gnus-command-method 'request-update-group-status)
 494        (gnus-group-real-name group) status
 495        (nth 1 gnus-command-method)))))
 496
 497 (defun gnus-request-set-mark (group action)
 498   "Set marks on articles in the back end."
 499   (let ((gnus-command-method (gnus-find-method-for-group group)))
 500     (if (not (gnus-check-backend-function
 501               'request-set-mark (car gnus-command-method)))
 502         action
 503       (funcall (gnus-get-function gnus-command-method 'request-set-mark)
 504                (gnus-group-real-name group) action
 505                (nth 1 gnus-command-method))
 506       (gnus-run-hook-with-args gnus-after-set-mark-hook group action))))
 507
 508 (defun gnus-request-update-mark (group article mark)
 509   "Allow the back end to change the mark the user tries to put on an article."
 510   (let ((gnus-command-method (gnus-find-method-for-group group)))
 511     (if (not (gnus-check-backend-function
 512               'request-update-mark (car gnus-command-method)))
 513         mark
 514       (gnus-run-hook-with-args gnus-before-update-mark-hook group article mark)
 515       (funcall (gnus-get-function gnus-command-method 'request-update-mark)
 516                (gnus-group-real-name group) article mark))))
 517
 518 (defun gnus-request-article (article group &optional buffer)
 519   "Request the ARTICLE in GROUP.
 520 ARTICLE can either be an article number or an article Message-ID.
 521 If BUFFER, insert the article in that group."
 522   (let ((gnus-command-method (gnus-find-method-for-group group)))
 523     (funcall (gnus-get-function gnus-command-method 'request-article)
 524              article (gnus-group-real-name group)
 525              (nth 1 gnus-command-method) buffer)))
 526
 527 (defun gnus-request-thread (header group)
 528   "Request the headers in the thread containing the article specified by HEADER."
 529   (let ((gnus-command-method (gnus-find-method-for-group group)))
 530     (funcall (gnus-get-function gnus-command-method 'request-thread)
 531              header
 532              (gnus-group-real-name group))))
 533
 534 (defun gnus-warp-to-article ()
 535   "Warps from an article in a virtual group to the article in its
 536 real group. Does nothing on a real group."
 537   (interactive)
 538   (let ((gnus-command-method
 539          (gnus-find-method-for-group gnus-newsgroup-name)))
 540     (when (gnus-check-backend-function
 541            'warp-to-article (car gnus-command-method))
 542       (funcall (gnus-get-function gnus-command-method 'warp-to-article)))))
 543
 544 (defun gnus-request-head (article group)
 545   "Request the head of ARTICLE in GROUP."
 546   (let* ((gnus-command-method (gnus-find-method-for-group group))
 547          (head (gnus-get-function gnus-command-method 'request-head t))
 548          res clean-up)
 549     (cond
 550      ;; Check the cache.
 551      ((and gnus-use-cache
 552            (numberp article)
 553            (gnus-cache-request-article article group))
 554       (setq res (cons group article)
 555             clean-up t))
 556      ;; Check the agent cache.
 557      ((gnus-agent-request-article article group)
 558       (setq res (cons group article)
 559             clean-up t))
 560      ;; Use `head' function.
 561      ((fboundp head)
 562       (setq res (funcall head article (gnus-group-real-name group)
 563                          (nth 1 gnus-command-method))))
 564      ;; Use `article' function.
 565      (t
 566       (setq res (gnus-request-article article group)
 567             clean-up t)))
 568     (when clean-up
 569       (with-current-buffer nntp-server-buffer
 570         (goto-char (point-min))
 571         (when (search-forward "\n\n" nil t)
 572           (delete-region (1- (point)) (point-max)))
 573         (nnheader-fold-continuation-lines)))
 574     res))
 575
 576 (defun gnus-request-body (article group)
 577   "Request the body of ARTICLE in GROUP."
 578   (let* ((gnus-command-method (gnus-find-method-for-group group))
 579          (head (gnus-get-function gnus-command-method 'request-body t))
 580          res clean-up)
 581     (cond
 582      ;; Check the cache.
 583      ((and gnus-use-cache
 584            (numberp article)
 585            (gnus-cache-request-article article group))
 586       (setq res (cons group article)
 587             clean-up t))
 588      ;; Check the agent cache.
 589      ((gnus-agent-request-article article group)
 590       (setq res (cons group article)
 591             clean-up t))
 592      ;; Use `head' function.
 593      ((fboundp head)
 594       (setq res (funcall head article (gnus-group-real-name group)
 595                          (nth 1 gnus-command-method))))
 596      ;; Use `article' function.
 597      (t
 598       (setq res (gnus-request-article article group)
 599             clean-up t)))
 600     (when clean-up
 601       (with-current-buffer nntp-server-buffer
 602         (goto-char (point-min))
 603         (when (search-forward "\n\n" nil t)
 604           (delete-region (point-min) (1- (point))))))
 605     res))
 606
 607 (defun gnus-request-post (gnus-command-method)
 608   "Post the current buffer using GNUS-COMMAND-METHOD."
 609   (when (stringp gnus-command-method)
 610     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 611   (funcall (gnus-get-function gnus-command-method 'request-post)
 612            (nth 1 gnus-command-method)))
 613
 614 (defun gnus-request-expunge-group (group gnus-command-method)
 615   "Expunge GROUP, which is removing articles that have been marked as deleted."
 616   (when (stringp gnus-command-method)
 617     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 618   (funcall (gnus-get-function gnus-command-method 'request-expunge-group)
 619            (gnus-group-real-name group)
 620            (nth 1 gnus-command-method)))
 621
 622 (defun gnus-request-scan (group gnus-command-method)
 623   "Request a SCAN being performed in GROUP from GNUS-COMMAND-METHOD.
 624 If GROUP is nil, all groups on GNUS-COMMAND-METHOD are scanned."
 625   (let ((gnus-command-method
 626          (if group (gnus-find-method-for-group group) gnus-command-method))
 627         (gnus-inhibit-demon t)
 628         (mail-source-plugged gnus-plugged))
 629     (when (or gnus-plugged
 630               (not (gnus-agent-method-p gnus-command-method)))
 631       (setq gnus-internal-registry-spool-current-method gnus-command-method)
 632       (funcall (gnus-get-function gnus-command-method 'request-scan)
 633                (and group (gnus-group-real-name group))
 634                (nth 1 gnus-command-method)))))
 635
 636 (defun gnus-request-update-info (info gnus-command-method)
 637   (when (gnus-check-backend-function
 638          'request-update-info (car gnus-command-method))
 639     (when (stringp gnus-command-method)
 640       (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 641     (funcall (gnus-get-function gnus-command-method 'request-update-info)
 642              (gnus-group-real-name (gnus-info-group info)) info
 643              (nth 1 gnus-command-method))))
 644
 645 (defsubst gnus-request-marks (info gnus-command-method)
 646   "Request that GNUS-COMMAND-METHOD update INFO."
 647   (when (stringp gnus-command-method)
 648     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 649   (when (gnus-check-backend-function
 650          'request-marks (car gnus-command-method))
 651     (let ((group (gnus-info-group info)))
 652       (and (funcall (gnus-get-function gnus-command-method 'request-marks)
 653                     (gnus-group-real-name group)
 654                     info (nth 1 gnus-command-method))
 655            ;; If the minimum article number is greater than 1, then all
 656            ;; smaller article numbers are known not to exist; we'll
 657            ;; artificially add those to the 'read range.
 658            (let* ((active (gnus-active group))
 659                   (min (car active)))
 660              (when (> min 1)
 661                (let* ((range (if (= min 2) 1 (cons 1 (1- min))))
 662                       (read (gnus-info-read info))
 663                       (new-read (gnus-range-add read (list range))))
 664                  (gnus-info-set-read info new-read)))
 665              info)))))
 666
 667 (defun gnus-request-expire-articles (articles group &optional force)
 668   (let* ((gnus-command-method (gnus-find-method-for-group group))
 669          (gnus-inhibit-demon t)
 670          (not-deleted
 671           (funcall
 672            (gnus-get-function gnus-command-method 'request-expire-articles)
 673            articles (gnus-group-real-name group) (nth 1 gnus-command-method)
 674            force)))
 675     (when (and gnus-agent
 676                (gnus-agent-method-p gnus-command-method))
 677       (let ((expired-articles (gnus-sorted-difference articles not-deleted)))
 678         (when expired-articles
 679           (gnus-agent-expire expired-articles group 'force))))
 680     not-deleted))
 681
 682 (defun gnus-request-move-article (article group server accept-function
 683                                           &optional last move-is-internal)
 684   (let* ((gnus-command-method (gnus-find-method-for-group group))
 685          (result (funcall (gnus-get-function gnus-command-method
 686                                              'request-move-article)
 687                           article (gnus-group-real-name group)
 688                           (nth 1 gnus-command-method) accept-function
 689                           last move-is-internal)))
 690     (when (and result gnus-agent
 691                (gnus-agent-method-p gnus-command-method))
 692       (gnus-agent-unfetch-articles group (list article)))
 693     result))
 694
 695 (defun gnus-request-accept-article (group &optional gnus-command-method last
 696                                           no-encode)
 697   ;; Make sure there's a newline at the end of the article.
 698   (when (stringp gnus-command-method)
 699     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 700   (when (and (not gnus-command-method)
 701              (stringp group))
 702     (setq gnus-command-method (or (gnus-find-method-for-group group)
 703                                   (gnus-group-name-to-method group))))
 704   (goto-char (point-max))
 705   (unless (bolp)
 706     (insert "\n"))
 707   (unless no-encode
 708     (let ((message-options message-options))
 709       (message-options-set-recipient)
 710       (save-restriction
 711         (message-narrow-to-head)
 712         (let ((mail-parse-charset message-default-charset))
 713           (mail-encode-encoded-word-buffer)))
 714       (message-encode-message-body)))
 715   (let ((gnus-command-method (or gnus-command-method
 716                                  (gnus-find-method-for-group group)))
 717         (result
 718          (funcall
 719           (gnus-get-function gnus-command-method 'request-accept-article)
 720           (if (stringp group) (gnus-group-real-name group) group)
 721           (cadr gnus-command-method)
 722           last)))
 723     (when (and gnus-agent
 724                (gnus-agent-method-p gnus-command-method)
 725                (cdr result))
 726       (gnus-agent-regenerate-group group (list (cdr result))))
 727     result))
 728
 729 (defun gnus-request-replace-article (article group buffer &optional no-encode)
 730   (unless no-encode
 731     (let ((message-options message-options))
 732       (message-options-set-recipient)
 733       (save-restriction
 734         (message-narrow-to-head)
 735         (let ((mail-parse-charset message-default-charset))
 736           (mail-encode-encoded-word-buffer)))
 737       (message-encode-message-body)))
 738   (let* ((func (car (gnus-group-name-to-method group)))
 739          (result (funcall (intern (format "%s-request-replace-article" func))
 740                           article (gnus-group-real-name group) buffer)))
 741     (when (and gnus-agent (gnus-agent-method-p gnus-command-method))
 742       (gnus-agent-regenerate-group group (list article)))
 743     result))
 744
 745 (defun gnus-request-associate-buffer (group)
 746   (let ((gnus-command-method (gnus-find-method-for-group group)))
 747     (funcall (gnus-get-function gnus-command-method 'request-associate-buffer)
 748              (gnus-group-real-name group))))
 749
 750 (defun gnus-request-restore-buffer (article group)
 751   "Request a new buffer restored to the state of ARTICLE."
 752   (let ((gnus-command-method (gnus-find-method-for-group group)))
 753     (funcall (gnus-get-function gnus-command-method 'request-restore-buffer)
 754              article (gnus-group-real-name group)
 755              (nth 1 gnus-command-method))))
 756
 757 (defun gnus-request-create-group (group &optional gnus-command-method args)
 758   (when (stringp gnus-command-method)
 759     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 760   (let ((gnus-command-method
 761          (or gnus-command-method (gnus-find-method-for-group group))))
 762     (funcall (gnus-get-function gnus-command-method 'request-create-group)
 763              (gnus-group-real-name group) (nth 1 gnus-command-method) args)))
 764
 765 (defun gnus-request-delete-group (group &optional force)
 766   (let* ((gnus-command-method (gnus-find-method-for-group group))
 767          (result
 768           (funcall (gnus-get-function gnus-command-method 'request-delete-group)
 769                    (gnus-group-real-name group) force (nth 1 gnus-command-method))))
 770     (when result
 771       (gnus-cache-delete-group group)
 772       (gnus-agent-delete-group group))
 773     result))
 774
 775 (defun gnus-request-rename-group (group new-name)
 776   (let* ((gnus-command-method (gnus-find-method-for-group group))
 777          (result
 778           (funcall (gnus-get-function gnus-command-method 'request-rename-group)
 779                    (gnus-group-real-name group)
 780                    (gnus-group-real-name new-name) (nth 1 gnus-command-method))))
 781     (when result
 782       (gnus-cache-rename-group group new-name)
 783       (gnus-agent-rename-group group new-name))
 784     result))
 785
 786 (defun gnus-close-backends ()
 787   ;; Send a close request to all backends that support such a request.
 788   (let ((methods gnus-valid-select-methods)
 789         (gnus-inhibit-demon t)
 790         func gnus-command-method)
 791     (while (setq gnus-command-method (pop methods))
 792       (when (fboundp (setq func (intern
 793                                  (concat (car gnus-command-method)
 794                                          "-request-close"))))
 795         (funcall func)))))
 796
 797 (defun gnus-asynchronous-p (gnus-command-method)
 798   (let ((func (gnus-get-function gnus-command-method 'asynchronous-p t)))
 799     (when (fboundp func)
 800       (funcall func))))
 801
 802 (defun gnus-remove-denial (gnus-command-method)
 803   (when (stringp gnus-command-method)
 804     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 805   (let* ((elem (assoc gnus-command-method gnus-opened-servers))
 806          (status (cadr elem)))
 807     ;; If this hasn't been opened before, we add it to the list.
 808     (when (eq status 'denied)
 809       ;; Set the status of this server.
 810       (setcar (cdr elem) 'closed))))
 811
 812 (provide 'gnus-int)
 813
 814 ;;; gnus-int.el ends here