lisp/gnus-int.el

   1 ;;; gnus-int.el --- backend interface functions for Gnus
   2
   3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
   4 ;;   2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   5
   6 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   7 ;; Keywords: news
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;;; Code:
  27
  28 (eval-when-compile (require 'cl))
  29
  30 (require 'gnus)
  31 (require 'message)
  32 (require 'gnus-range)
  33
  34 (autoload 'gnus-run-hook-with-args "gnus-util")
  35 (autoload 'gnus-agent-expire "gnus-agent")
  36 (autoload 'gnus-agent-regenerate-group "gnus-agent")
  37 (autoload 'gnus-agent-read-servers-validate-native "gnus-agent")
  38 (autoload 'gnus-agent-possibly-synchronize-flags-server "gnus-agent")
  39
  40 (defcustom gnus-open-server-hook nil
  41   "Hook called just before opening connection to the news server."
  42   :group 'gnus-start
  43   :type 'hook)
  44
  45 (defcustom gnus-after-set-mark-hook nil
  46   "Hook called just after marks are set in a group."
  47   :group 'gnus-start
  48   :type 'hook)
  49
  50 (defcustom gnus-before-update-mark-hook nil
  51   "Hook called just before marks are updated in a group."
  52   :group 'gnus-start
  53   :type 'hook)
  54
  55 (defcustom gnus-server-unopen-status nil
  56   "The default status if the server is not able to open.
  57 If the server is covered by Gnus agent, the possible values are
  58 `denied', set the server denied; `offline', set the server offline;
  59 nil, ask user.  If the server is not covered by Gnus agent, set the
  60 server denied."
  61   :version "22.1"
  62   :group 'gnus-start
  63   :type '(choice (const :tag "Ask" nil)
  64                  (const :tag "Deny server" denied)
  65                  (const :tag "Unplug Agent" offline)))
  66
  67 (defvar gnus-internal-registry-spool-current-method nil
  68   "The current method, for the registry.")
  69
  70
  71 (defun gnus-server-opened (gnus-command-method)
  72   "Check whether a connection to GNUS-COMMAND-METHOD has been opened."
  73   (unless (eq (gnus-server-status gnus-command-method)
  74               'denied)
  75     (when (stringp gnus-command-method)
  76       (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
  77     (funcall (inline (gnus-get-function gnus-command-method 'server-opened))
  78              (nth 1 gnus-command-method))))
  79
  80 (defun gnus-status-message (gnus-command-method)
  81   "Return the status message from GNUS-COMMAND-METHOD.
  82 If GNUS-COMMAND-METHOD is a string, it is interpreted as a group
  83 name.  The method this group uses will be queried."
  84   (let ((gnus-command-method
  85          (if (stringp gnus-command-method)
  86              (gnus-find-method-for-group gnus-command-method)
  87            gnus-command-method)))
  88     (funcall (gnus-get-function gnus-command-method 'status-message)
  89              (nth 1 gnus-command-method))))
  90
  91 ;;;
  92 ;;; Server Communication
  93 ;;;
  94
  95 (defun gnus-start-news-server (&optional confirm)
  96   "Open a method for getting news.
  97 If CONFIRM is non-nil, the user will be asked for an NNTP server."
  98   (let (how)
  99     (if gnus-current-select-method
 100         ;; Stream is already opened.
 101         nil
 102       ;; Open NNTP server.
 103       (when confirm
 104         ;; Read server name with completion.
 105         (setq gnus-nntp-server
 106               (gnus-completing-read "NNTP server"
 107                                     (cons gnus-nntp-server
 108                                           gnus-secondary-servers)
 109                                     nil gnus-nntp-server)))
 110
 111       (when (and gnus-nntp-server
 112                  (stringp gnus-nntp-server)
 113                  (not (string= gnus-nntp-server "")))
 114         (setq gnus-select-method
 115               (cond ((or (string= gnus-nntp-server "")
 116                          (string= gnus-nntp-server "::"))
 117                      (list 'nnspool (system-name)))
 118                     ((string-match "^:" gnus-nntp-server)
 119                      (list 'nnmh gnus-nntp-server
 120                            (list 'nnmh-directory
 121                                  (file-name-as-directory
 122                                   (expand-file-name
 123                                    (substring gnus-nntp-server 1) "~/")))
 124                            (list 'nnmh-get-new-mail nil)))
 125                     (t
 126                      (list 'nntp gnus-nntp-server)))))
 127
 128       (setq how (car gnus-select-method))
 129       (cond
 130        ((eq how 'nnspool)
 131         (require 'nnspool)
 132         (gnus-message 5 "Looking up local news spool..."))
 133        ((eq how 'nnmh)
 134         (require 'nnmh)
 135         (gnus-message 5 "Looking up mh spool..."))
 136        (t
 137         (require 'nntp)))
 138       (setq gnus-current-select-method gnus-select-method)
 139       (gnus-run-hooks 'gnus-open-server-hook)
 140
 141       ;; Partially validate agent covered methods now that the
 142       ;; gnus-select-method is known.
 143
 144       (if gnus-agent
 145           ;; NOTE: This is here for one purpose only.  By validating
 146           ;; the current select method, it converts the old 5.10.3,
 147           ;; and earlier, format to the current format.  That enables
 148           ;; the agent code within gnus-open-server to function
 149           ;; correctly.
 150           (gnus-agent-read-servers-validate-native gnus-select-method))
 151
 152       (or
 153        ;; gnus-open-server-hook might have opened it
 154        (gnus-server-opened gnus-select-method)
 155        (gnus-open-server gnus-select-method)
 156        gnus-batch-mode
 157        (gnus-y-or-n-p
 158         (format
 159          "%s (%s) open error: '%s'.  Continue? "
 160          (car gnus-select-method) (cadr gnus-select-method)
 161          (gnus-status-message gnus-select-method)))
 162        (gnus-error 1 "Couldn't open server on %s"
 163                    (nth 1 gnus-select-method))))))
 164
 165 (defun gnus-check-group (group)
 166   "Try to make sure that the server where GROUP exists is alive."
 167   (let ((method (gnus-find-method-for-group group)))
 168     (or (gnus-server-opened method)
 169         (gnus-open-server method))))
 170
 171 (defun gnus-check-server (&optional method silent)
 172   "Check whether the connection to METHOD is down.
 173 If METHOD is nil, use `gnus-select-method'.
 174 If it is down, start it up (again)."
 175   (let ((method (or method gnus-select-method))
 176         result)
 177     ;; Transform virtual server names into select methods.
 178     (when (stringp method)
 179       (setq method (gnus-server-to-method method)))
 180     (if (gnus-server-opened method)
 181         ;; The stream is already opened.
 182         t
 183       ;; Open the server.
 184       (unless silent
 185         (gnus-message 5 "Opening %s server%s..." (car method)
 186                       (if (equal (nth 1 method) "") ""
 187                         (format " on %s" (nth 1 method)))))
 188       (gnus-run-hooks 'gnus-open-server-hook)
 189       (prog1
 190           (setq result (gnus-open-server method))
 191         (unless silent
 192           (gnus-message
 193            (if result 5 3)
 194            "Opening %s server%s...%s" (car method)
 195            (if (equal (nth 1 method) "") ""
 196              (format " on %s" (nth 1 method)))
 197            (if result
 198                "done"
 199              (format "failed: %s"
 200                      (nnheader-get-report-string (car method))))))))))
 201
 202 (defun gnus-get-function (method function &optional noerror)
 203   "Return a function symbol based on METHOD and FUNCTION."
 204   ;; Translate server names into methods.
 205   (unless method
 206     (error "Attempted use of a nil select method"))
 207   (when (stringp method)
 208     (setq method (gnus-server-to-method method)))
 209   ;; Check cache of constructed names.
 210   (let* ((method-sym (if gnus-agent
 211                          (inline (gnus-agent-get-function method))
 212                        (car method)))
 213          (method-fns (get method-sym 'gnus-method-functions))
 214          (func (let ((method-fnlist-elt (assq function method-fns)))
 215                  (unless method-fnlist-elt
 216                    (setq method-fnlist-elt
 217                          (cons function
 218                                (intern (format "%s-%s" method-sym function))))
 219                    (put method-sym 'gnus-method-functions
 220                         (cons method-fnlist-elt method-fns)))
 221                  (cdr method-fnlist-elt))))
 222     ;; Maybe complain if there is no function.
 223     (unless (fboundp func)
 224       (unless (car method)
 225         (error "Trying to require a method that doesn't exist"))
 226       (require (car method))
 227       (when (not (fboundp func))
 228         (if noerror
 229             (setq func nil)
 230           (error "No such function: %s" func))))
 231     func))
 232
 233 \f
 234 ;;;
 235 ;;; Interface functions to the backends.
 236 ;;;
 237
 238 (defun gnus-method-denied-p (method)
 239   (eq (nth 1 (assoc method gnus-opened-servers))
 240       'denied))
 241
 242 (defvar gnus-backend-trace t)
 243
 244 (defun gnus-open-server (gnus-command-method)
 245   "Open a connection to GNUS-COMMAND-METHOD."
 246   (when (stringp gnus-command-method)
 247     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 248   (when gnus-backend-trace
 249     (with-current-buffer (get-buffer-create "*gnus trace*")
 250       (buffer-disable-undo)
 251       (goto-char (point-max))
 252       (insert (format-time-string "%H:%M:%S")
 253               (format " %S\n" gnus-command-method))))
 254   (let ((elem (assoc gnus-command-method gnus-opened-servers))
 255         (server (gnus-method-to-server-name gnus-command-method)))
 256     ;; If this method was previously denied, we just return nil.
 257     (if (eq (nth 1 elem) 'denied)
 258         (progn
 259           (gnus-message 1 "Denied server %s" server)
 260           nil)
 261       ;; Open the server.
 262       (let* ((open-server-function (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                 (gnus-message 1 "Quit trying to open server %s" server)
 274                 nil)))
 275             open-offline)
 276         ;; If this hasn't been opened before, we add it to the list.
 277         (unless elem
 278           (setq elem (list gnus-command-method nil)
 279                 gnus-opened-servers (cons elem gnus-opened-servers)))
 280         ;; Set the status of this server.
 281         (setcar
 282          (cdr elem)
 283          (cond (result
 284                 (if (eq open-server-function #'nnagent-open-server)
 285                     ;; The agent's backend has a "special" status
 286                     'offline
 287                   'ok))
 288                ((and gnus-agent
 289                      (gnus-agent-method-p gnus-command-method))
 290                 (cond
 291                  (gnus-server-unopen-status
 292                   ;; Set the server's status to the unopen
 293                   ;; status.  If that status is offline,
 294                   ;; recurse to open the agent's backend.
 295                   (setq open-offline (eq gnus-server-unopen-status 'offline))
 296                   gnus-server-unopen-status)
 297                  ((not gnus-batch-mode)
 298                   (setq open-offline t)
 299                   'offline)
 300                  (t
 301                   ;; This agentized server was still denied
 302                   'denied)))
 303                (t
 304                 ;; This unagentized server must be denied
 305                 'denied)))
 306
 307         ;; NOTE: I MUST set the server's status to offline before this
 308         ;; recursive call as this status will drive the
 309         ;; gnus-get-function (called above) to return the agent's
 310         ;; backend.
 311         (if open-offline
 312             ;; Recursively open this offline server to perform the
 313             ;; open-server function of the agent's backend.
 314             (let ((gnus-server-unopen-status 'denied))
 315               ;; Bind gnus-server-unopen-status to avoid recursively
 316               ;; prompting with "go offline?".  This is only a concern
 317               ;; when the agent's backend fails to open the server.
 318               (gnus-open-server gnus-command-method))
 319           (when (and (eq (cadr elem) 'ok) gnus-agent
 320                      (gnus-agent-method-p gnus-command-method))
 321             (save-excursion
 322               (gnus-agent-possibly-synchronize-flags-server
 323                gnus-command-method)))
 324           result)))))
 325
 326 (defun gnus-close-server (gnus-command-method)
 327   "Close the connection to GNUS-COMMAND-METHOD."
 328   (when (stringp gnus-command-method)
 329     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 330   (funcall (gnus-get-function gnus-command-method 'close-server)
 331            (nth 1 gnus-command-method)))
 332
 333 (defun gnus-request-list (gnus-command-method)
 334   "Request the active file from GNUS-COMMAND-METHOD."
 335   (when (stringp gnus-command-method)
 336     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 337   (funcall (gnus-get-function gnus-command-method 'request-list)
 338            (nth 1 gnus-command-method)))
 339
 340 (defun gnus-finish-retrieve-group-infos (gnus-command-method infos data)
 341   "Read and update infos from GNUS-COMMAND-METHOD."
 342   (when (stringp gnus-command-method)
 343     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 344   (funcall (gnus-get-function gnus-command-method 'finish-retrieve-group-infos)
 345            (nth 1 gnus-command-method)
 346            infos data))
 347
 348 (defun gnus-retrieve-group-data-early (gnus-command-method infos)
 349   "Start early async retrival of data from GNUS-COMMAND-METHOD."
 350   (when (stringp gnus-command-method)
 351     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 352   (funcall (gnus-get-function gnus-command-method 'retrieve-group-data-early)
 353            (nth 1 gnus-command-method)
 354            infos))
 355
 356 (defun gnus-request-list-newsgroups (gnus-command-method)
 357   "Request the newsgroups file from GNUS-COMMAND-METHOD."
 358   (when (stringp gnus-command-method)
 359     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 360   (funcall (gnus-get-function gnus-command-method 'request-list-newsgroups)
 361            (nth 1 gnus-command-method)))
 362
 363 (defun gnus-request-newgroups (date gnus-command-method)
 364   "Request all new groups since DATE from GNUS-COMMAND-METHOD."
 365   (when (stringp gnus-command-method)
 366     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 367   (let ((func (gnus-get-function gnus-command-method 'request-newgroups t)))
 368     (when func
 369       (funcall func date (nth 1 gnus-command-method)))))
 370
 371 (defun gnus-request-regenerate (gnus-command-method)
 372   "Request a data generation from GNUS-COMMAND-METHOD."
 373   (when (stringp gnus-command-method)
 374     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 375   (funcall (gnus-get-function gnus-command-method 'request-regenerate)
 376            (nth 1 gnus-command-method)))
 377
 378 (defun gnus-request-compact-group (group)
 379   (let* ((method (gnus-find-method-for-group group))
 380          (gnus-command-method method)
 381          (result
 382           (funcall (gnus-get-function gnus-command-method
 383                                       'request-compact-group)
 384                    (gnus-group-real-name group)
 385                    (nth 1 gnus-command-method) t)))
 386     result))
 387
 388 (defun gnus-request-compact (gnus-command-method)
 389   "Request groups compaction  from GNUS-COMMAND-METHOD."
 390   (when (stringp gnus-command-method)
 391     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 392   (funcall (gnus-get-function gnus-command-method 'request-compact)
 393            (nth 1 gnus-command-method)))
 394
 395 (defun gnus-request-group (group &optional dont-check gnus-command-method info)
 396   "Request GROUP.  If DONT-CHECK, no information is required."
 397   (let ((gnus-command-method
 398          (or gnus-command-method (inline (gnus-find-method-for-group group)))))
 399     (when (stringp gnus-command-method)
 400       (setq gnus-command-method
 401             (inline (gnus-server-to-method gnus-command-method))))
 402     (funcall (inline (gnus-get-function gnus-command-method 'request-group))
 403              (gnus-group-real-name group) (nth 1 gnus-command-method)
 404              dont-check
 405              info)))
 406
 407 (defun gnus-list-active-group (group)
 408   "Request active information on GROUP."
 409   (let ((gnus-command-method (gnus-find-method-for-group group))
 410         (func 'list-active-group))
 411     (when (gnus-check-backend-function func group)
 412       (funcall (gnus-get-function gnus-command-method func)
 413                (gnus-group-real-name group) (nth 1 gnus-command-method)))))
 414
 415 (defun gnus-request-group-description (group)
 416   "Request a description of GROUP."
 417   (let ((gnus-command-method (gnus-find-method-for-group group))
 418         (func 'request-group-description))
 419     (when (gnus-check-backend-function func group)
 420       (funcall (gnus-get-function gnus-command-method func)
 421                (gnus-group-real-name group) (nth 1 gnus-command-method)))))
 422
 423 (defun gnus-request-group-articles (group)
 424   "Request a list of existing articles in GROUP."
 425   (let ((gnus-command-method (gnus-find-method-for-group group))
 426         (func 'request-group-articles))
 427     (when (gnus-check-backend-function func group)
 428       (funcall (gnus-get-function gnus-command-method func)
 429                (gnus-group-real-name group) (nth 1 gnus-command-method)))))
 430
 431 (defun gnus-close-group (group)
 432   "Request the GROUP be closed."
 433   (let ((gnus-command-method (inline (gnus-find-method-for-group group))))
 434     (funcall (gnus-get-function gnus-command-method 'close-group)
 435              (gnus-group-real-name group) (nth 1 gnus-command-method))))
 436
 437 (defun gnus-retrieve-headers (articles group &optional fetch-old)
 438   "Request headers for ARTICLES in GROUP.
 439 If FETCH-OLD, retrieve all headers (or some subset thereof) in the group."
 440   (let ((gnus-command-method (gnus-find-method-for-group group)))
 441     (cond
 442      ((and gnus-use-cache (numberp (car articles)))
 443       (gnus-cache-retrieve-headers articles group fetch-old))
 444      ((and gnus-agent (gnus-online gnus-command-method)
 445            (gnus-agent-method-p gnus-command-method))
 446       (gnus-agent-retrieve-headers articles group fetch-old))
 447      (t
 448       (funcall (gnus-get-function gnus-command-method 'retrieve-headers)
 449                articles (gnus-group-real-name group)
 450                (nth 1 gnus-command-method) fetch-old)))))
 451
 452 (defun gnus-retrieve-articles (articles group)
 453   "Request ARTICLES in GROUP."
 454   (let ((gnus-command-method (gnus-find-method-for-group group)))
 455     (funcall (gnus-get-function gnus-command-method 'retrieve-articles)
 456              articles (gnus-group-real-name group)
 457              (nth 1 gnus-command-method))))
 458
 459 (defun gnus-retrieve-groups (groups gnus-command-method)
 460   "Request active information on GROUPS from GNUS-COMMAND-METHOD."
 461   (when (stringp gnus-command-method)
 462     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 463   (funcall (gnus-get-function gnus-command-method 'retrieve-groups)
 464            groups (nth 1 gnus-command-method)))
 465
 466 (defun gnus-request-type (group &optional article)
 467   "Return the type (`post' or `mail') of GROUP (and ARTICLE)."
 468   (let ((gnus-command-method (gnus-find-method-for-group group)))
 469     (if (not (gnus-check-backend-function
 470               'request-type (car gnus-command-method)))
 471         'unknown
 472       (funcall (gnus-get-function gnus-command-method 'request-type)
 473                (gnus-group-real-name group) article))))
 474
 475 (defun gnus-request-set-mark (group action)
 476   "Set marks on articles in the back end."
 477   (let ((gnus-command-method (gnus-find-method-for-group group)))
 478     (if (not (gnus-check-backend-function
 479               'request-set-mark (car gnus-command-method)))
 480         action
 481       (funcall (gnus-get-function gnus-command-method 'request-set-mark)
 482                (gnus-group-real-name group) action
 483                (nth 1 gnus-command-method))
 484       (gnus-run-hook-with-args gnus-after-set-mark-hook group action))))
 485
 486 (defun gnus-request-update-mark (group article mark)
 487   "Allow the back end to change the mark the user tries to put on an article."
 488   (let ((gnus-command-method (gnus-find-method-for-group group)))
 489     (if (not (gnus-check-backend-function
 490               'request-update-mark (car gnus-command-method)))
 491         mark
 492       (gnus-run-hook-with-args gnus-before-update-mark-hook group article mark)
 493       (funcall (gnus-get-function gnus-command-method 'request-update-mark)
 494                (gnus-group-real-name group) article mark))))
 495
 496 (defun gnus-request-article (article group &optional buffer)
 497   "Request the ARTICLE in GROUP.
 498 ARTICLE can either be an article number or an article Message-ID.
 499 If BUFFER, insert the article in that group."
 500   (let ((gnus-command-method (gnus-find-method-for-group group)))
 501     (funcall (gnus-get-function gnus-command-method 'request-article)
 502              article (gnus-group-real-name group)
 503              (nth 1 gnus-command-method) buffer)))
 504
 505 (defun gnus-request-thread (id)
 506   "Request the headers in the thread containing the article
 507 specified by Message-ID id."
 508   (let ((gnus-command-method (gnus-find-method-for-group gnus-newsgroup-name)))
 509     (funcall (gnus-get-function gnus-command-method 'request-thread)
 510              id)))
 511
 512 (defun gnus-warp-to-article ()
 513   "Warps from an article in a virtual group to the article in its
 514 real group. Does nothing on a real group."
 515   (interactive)
 516   (let ((gnus-command-method
 517          (gnus-find-method-for-group gnus-newsgroup-name)))
 518     (when (gnus-check-backend-function
 519            'warp-to-article (car gnus-command-method))
 520       (funcall (gnus-get-function gnus-command-method 'warp-to-article)))))
 521
 522 (defun gnus-request-head (article group)
 523   "Request the head of ARTICLE in GROUP."
 524   (let* ((gnus-command-method (gnus-find-method-for-group group))
 525          (head (gnus-get-function gnus-command-method 'request-head t))
 526          res clean-up)
 527     (cond
 528      ;; Check the cache.
 529      ((and gnus-use-cache
 530            (numberp article)
 531            (gnus-cache-request-article article group))
 532       (setq res (cons group article)
 533             clean-up t))
 534      ;; Check the agent cache.
 535      ((gnus-agent-request-article article group)
 536       (setq res (cons group article)
 537             clean-up t))
 538      ;; Use `head' function.
 539      ((fboundp head)
 540       (setq res (funcall head article (gnus-group-real-name group)
 541                          (nth 1 gnus-command-method))))
 542      ;; Use `article' function.
 543      (t
 544       (setq res (gnus-request-article article group)
 545             clean-up t)))
 546     (when clean-up
 547       (with-current-buffer nntp-server-buffer
 548         (goto-char (point-min))
 549         (when (search-forward "\n\n" nil t)
 550           (delete-region (1- (point)) (point-max)))
 551         (nnheader-fold-continuation-lines)))
 552     res))
 553
 554 (defun gnus-request-body (article group)
 555   "Request the body of ARTICLE in GROUP."
 556   (let* ((gnus-command-method (gnus-find-method-for-group group))
 557          (head (gnus-get-function gnus-command-method 'request-body t))
 558          res clean-up)
 559     (cond
 560      ;; Check the cache.
 561      ((and gnus-use-cache
 562            (numberp article)
 563            (gnus-cache-request-article article group))
 564       (setq res (cons group article)
 565             clean-up t))
 566      ;; Check the agent cache.
 567      ((gnus-agent-request-article article group)
 568       (setq res (cons group article)
 569             clean-up t))
 570      ;; Use `head' function.
 571      ((fboundp head)
 572       (setq res (funcall head article (gnus-group-real-name group)
 573                          (nth 1 gnus-command-method))))
 574      ;; Use `article' function.
 575      (t
 576       (setq res (gnus-request-article article group)
 577             clean-up t)))
 578     (when clean-up
 579       (with-current-buffer nntp-server-buffer
 580         (goto-char (point-min))
 581         (when (search-forward "\n\n" nil t)
 582           (delete-region (point-min) (1- (point))))))
 583     res))
 584
 585 (defun gnus-request-post (gnus-command-method)
 586   "Post the current buffer using GNUS-COMMAND-METHOD."
 587   (when (stringp gnus-command-method)
 588     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 589   (funcall (gnus-get-function gnus-command-method 'request-post)
 590            (nth 1 gnus-command-method)))
 591
 592 (defun gnus-request-expunge-group (group gnus-command-method)
 593   "Expunge GROUP, which is removing articles that have been marked as deleted."
 594   (when (stringp gnus-command-method)
 595     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 596   (funcall (gnus-get-function gnus-command-method 'request-expunge-group)
 597            (gnus-group-real-name group)
 598            (nth 1 gnus-command-method)))
 599
 600 (defun gnus-request-scan (group gnus-command-method)
 601   "Request a SCAN being performed in GROUP from GNUS-COMMAND-METHOD.
 602 If GROUP is nil, all groups on GNUS-COMMAND-METHOD are scanned."
 603   (let ((gnus-command-method
 604          (if group (gnus-find-method-for-group group) gnus-command-method))
 605         (gnus-inhibit-demon t)
 606         (mail-source-plugged gnus-plugged))
 607     (when (or gnus-plugged
 608               (not (gnus-agent-method-p gnus-command-method)))
 609       (setq gnus-internal-registry-spool-current-method gnus-command-method)
 610       (funcall (gnus-get-function gnus-command-method 'request-scan)
 611                (and group (gnus-group-real-name group))
 612                (nth 1 gnus-command-method)))))
 613
 614 (defun gnus-request-update-info (info gnus-command-method)
 615   (when (gnus-check-backend-function
 616          'request-update-info (car gnus-command-method))
 617     (when (stringp gnus-command-method)
 618       (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 619     (funcall (gnus-get-function gnus-command-method 'request-update-info)
 620              (gnus-group-real-name (gnus-info-group info)) info
 621              (nth 1 gnus-command-method))))
 622
 623 (defsubst gnus-request-marks (info gnus-command-method)
 624   "Request that GNUS-COMMAND-METHOD update INFO."
 625   (when (stringp gnus-command-method)
 626     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 627   (when (gnus-check-backend-function
 628          'request-marks (car gnus-command-method))
 629     (let ((group (gnus-info-group info)))
 630       (and (funcall (gnus-get-function gnus-command-method
 631                                        'request-update-info)
 632                     (gnus-group-real-name group)
 633                     info (nth 1 gnus-command-method))
 634            ;; If the minimum article number is greater than 1, then all
 635            ;; smaller article numbers are known not to exist; we'll
 636            ;; artificially add those to the 'read range.
 637            (let* ((active (gnus-active group))
 638                   (min (car active)))
 639              (when (> min 1)
 640                (let* ((range (if (= min 2) 1 (cons 1 (1- min))))
 641                       (read (gnus-info-read info))
 642                       (new-read (gnus-range-add read (list range))))
 643                  (gnus-info-set-read info new-read)))
 644              info)))))
 645
 646 (defun gnus-request-expire-articles (articles group &optional force)
 647   (let* ((gnus-command-method (gnus-find-method-for-group group))
 648          (gnus-inhibit-demon t)
 649          (not-deleted
 650           (funcall
 651            (gnus-get-function gnus-command-method 'request-expire-articles)
 652            articles (gnus-group-real-name group) (nth 1 gnus-command-method)
 653            force)))
 654     (when (and gnus-agent
 655                (gnus-agent-method-p gnus-command-method))
 656       (let ((expired-articles (gnus-sorted-difference articles not-deleted)))
 657         (when expired-articles
 658           (gnus-agent-expire expired-articles group 'force))))
 659     not-deleted))
 660
 661 (defun gnus-request-move-article (article group server accept-function
 662                                           &optional last move-is-internal)
 663   (let* ((gnus-command-method (gnus-find-method-for-group group))
 664          (result (funcall (gnus-get-function gnus-command-method
 665                                              'request-move-article)
 666                           article (gnus-group-real-name group)
 667                           (nth 1 gnus-command-method) accept-function
 668                           last move-is-internal)))
 669     (when (and result gnus-agent
 670                (gnus-agent-method-p gnus-command-method))
 671       (gnus-agent-unfetch-articles group (list article)))
 672     result))
 673
 674 (defun gnus-request-accept-article (group &optional gnus-command-method last
 675                                           no-encode)
 676   ;; Make sure there's a newline at the end of the article.
 677   (when (stringp gnus-command-method)
 678     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 679   (when (and (not gnus-command-method)
 680              (stringp group))
 681     (setq gnus-command-method (or (gnus-find-method-for-group group)
 682                                   (gnus-group-name-to-method group))))
 683   (goto-char (point-max))
 684   (unless (bolp)
 685     (insert "\n"))
 686   (unless no-encode
 687     (let ((message-options message-options))
 688       (message-options-set-recipient)
 689       (save-restriction
 690         (message-narrow-to-head)
 691         (let ((mail-parse-charset message-default-charset))
 692           (mail-encode-encoded-word-buffer)))
 693       (message-encode-message-body)))
 694   (let ((gnus-command-method (or gnus-command-method
 695                                  (gnus-find-method-for-group group)))
 696         (result
 697          (funcall
 698           (gnus-get-function gnus-command-method 'request-accept-article)
 699           (if (stringp group) (gnus-group-real-name group) group)
 700           (cadr gnus-command-method)
 701           last)))
 702     (when (and gnus-agent (gnus-agent-method-p gnus-command-method))
 703       (gnus-agent-regenerate-group group (list (cdr result))))
 704     result))
 705
 706 (defun gnus-request-replace-article (article group buffer &optional no-encode)
 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* ((func (car (gnus-group-name-to-method group)))
 716          (result (funcall (intern (format "%s-request-replace-article" func))
 717                           article (gnus-group-real-name group) buffer)))
 718     (when (and gnus-agent (gnus-agent-method-p gnus-command-method))
 719       (gnus-agent-regenerate-group group (list article)))
 720     result))
 721
 722 (defun gnus-request-associate-buffer (group)
 723   (let ((gnus-command-method (gnus-find-method-for-group group)))
 724     (funcall (gnus-get-function gnus-command-method 'request-associate-buffer)
 725              (gnus-group-real-name group))))
 726
 727 (defun gnus-request-restore-buffer (article group)
 728   "Request a new buffer restored to the state of ARTICLE."
 729   (let ((gnus-command-method (gnus-find-method-for-group group)))
 730     (funcall (gnus-get-function gnus-command-method 'request-restore-buffer)
 731              article (gnus-group-real-name group)
 732              (nth 1 gnus-command-method))))
 733
 734 (defun gnus-request-create-group (group &optional gnus-command-method args)
 735   (when (stringp gnus-command-method)
 736     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 737   (let ((gnus-command-method
 738          (or gnus-command-method (gnus-find-method-for-group group))))
 739     (funcall (gnus-get-function gnus-command-method 'request-create-group)
 740              (gnus-group-real-name group) (nth 1 gnus-command-method) args)))
 741
 742 (defun gnus-request-delete-group (group &optional force)
 743   (let* ((gnus-command-method (gnus-find-method-for-group group))
 744          (result
 745           (funcall (gnus-get-function gnus-command-method 'request-delete-group)
 746                    (gnus-group-real-name group) force (nth 1 gnus-command-method))))
 747     (when result
 748       (gnus-cache-delete-group group)
 749       (gnus-agent-delete-group group))
 750     result))
 751
 752 (defun gnus-request-rename-group (group new-name)
 753   (let* ((gnus-command-method (gnus-find-method-for-group group))
 754          (result
 755           (funcall (gnus-get-function gnus-command-method 'request-rename-group)
 756                    (gnus-group-real-name group)
 757                    (gnus-group-real-name new-name) (nth 1 gnus-command-method))))
 758     (when result
 759       (gnus-cache-rename-group group new-name)
 760       (gnus-agent-rename-group group new-name))
 761     result))
 762
 763 (defun gnus-close-backends ()
 764   ;; Send a close request to all backends that support such a request.
 765   (let ((methods gnus-valid-select-methods)
 766         (gnus-inhibit-demon t)
 767         func gnus-command-method)
 768     (while (setq gnus-command-method (pop methods))
 769       (when (fboundp (setq func (intern
 770                                  (concat (car gnus-command-method)
 771                                          "-request-close"))))
 772         (funcall func)))))
 773
 774 (defun gnus-asynchronous-p (gnus-command-method)
 775   (let ((func (gnus-get-function gnus-command-method 'asynchronous-p t)))
 776     (when (fboundp func)
 777       (funcall func))))
 778
 779 (defun gnus-remove-denial (gnus-command-method)
 780   (when (stringp gnus-command-method)
 781     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 782   (let* ((elem (assoc gnus-command-method gnus-opened-servers))
 783          (status (cadr elem)))
 784     ;; If this hasn't been opened before, we add it to the list.
 785     (when (eq status 'denied)
 786       ;; Set the status of this server.
 787       (setcar (cdr elem) 'closed))))
 788
 789 (provide 'gnus-int)
 790
 791 ;;; gnus-int.el ends here