lisp/gnus/gnus-int.el

   1 ;;; gnus-int.el --- backend interface functions for Gnus
   2
   3 ;; Copyright (C) 1996-2015 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   :version "24.1"
  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   :version "24.1"
  53   :group 'gnus-start
  54   :type 'hook)
  55
  56 (defcustom gnus-server-unopen-status nil
  57   "The default status if the server is not able to open.
  58 If the server is covered by Gnus agent, the possible values are
  59 `denied', set the server denied; `offline', set the server offline;
  60 nil, ask user.  If the server is not covered by Gnus agent, set the
  61 server denied."
  62   :version "22.1"
  63   :group 'gnus-start
  64   :type '(choice (const :tag "Ask" nil)
  65                  (const :tag "Deny server" denied)
  66                  (const :tag "Unplug Agent" offline)))
  67
  68 (defcustom gnus-nntp-server nil
  69   "The name of the host running the NNTP server."
  70   :group 'gnus-server
  71   :type '(choice (const :tag "disable" nil)
  72                  string))
  73 (make-obsolete-variable 'gnus-nntp-server 'gnus-select-method "24.1")
  74
  75 (defvar gnus-internal-registry-spool-current-method nil
  76   "The current method, for the registry.")
  77
  78
  79 (defun gnus-server-opened (gnus-command-method)
  80   "Check whether a connection to GNUS-COMMAND-METHOD has been opened."
  81   (unless (eq (gnus-server-status gnus-command-method)
  82               'denied)
  83     (when (stringp gnus-command-method)
  84       (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
  85     (funcall (inline (gnus-get-function gnus-command-method 'server-opened))
  86              (nth 1 gnus-command-method))))
  87
  88 (defun gnus-status-message (gnus-command-method)
  89   "Return the status message from GNUS-COMMAND-METHOD.
  90 If GNUS-COMMAND-METHOD is a string, it is interpreted as a group
  91 name.  The method this group uses will be queried."
  92   (let ((gnus-command-method
  93          (if (stringp gnus-command-method)
  94              (gnus-find-method-for-group gnus-command-method)
  95            gnus-command-method)))
  96     (funcall (gnus-get-function gnus-command-method 'status-message)
  97              (nth 1 gnus-command-method))))
  98
  99 ;;;
 100 ;;; Server Communication
 101 ;;;
 102
 103 (defun gnus-start-news-server (&optional confirm)
 104   "Open a method for getting news.
 105 If CONFIRM is non-nil, the user will be asked for an NNTP server."
 106   (let (how)
 107     (if gnus-current-select-method
 108         ;; Stream is already opened.
 109         nil
 110       ;; Open NNTP server.
 111       (when confirm
 112         ;; Read server name with completion.
 113         (setq gnus-nntp-server
 114               (gnus-completing-read "NNTP server"
 115                                     (cons gnus-nntp-server
 116                                           (if (boundp 'gnus-secondary-servers)
 117                                               gnus-secondary-servers))
 118                                     nil gnus-nntp-server)))
 119
 120       (when (and gnus-nntp-server
 121                  (stringp gnus-nntp-server)
 122                  (not (string= gnus-nntp-server "")))
 123         (setq gnus-select-method
 124               (cond ((or (string= gnus-nntp-server "")
 125                          (string= gnus-nntp-server "::"))
 126                      (list 'nnspool (system-name)))
 127                     ((string-match "^:" gnus-nntp-server)
 128                      (list 'nnmh gnus-nntp-server
 129                            (list 'nnmh-directory
 130                                  (file-name-as-directory
 131                                   (expand-file-name
 132                                    (substring gnus-nntp-server 1) "~/")))
 133                            (list 'nnmh-get-new-mail nil)))
 134                     (t
 135                      (list 'nntp gnus-nntp-server)))))
 136
 137       (setq how (car gnus-select-method))
 138       (cond
 139        ((eq how 'nnspool)
 140         (require 'nnspool)
 141         (gnus-message 5 "Looking up local news spool..."))
 142        ((eq how 'nnmh)
 143         (require 'nnmh)
 144         (gnus-message 5 "Looking up mh spool..."))
 145        (t
 146         (require 'nntp)))
 147       (setq gnus-current-select-method gnus-select-method)
 148       (gnus-run-hooks 'gnus-open-server-hook)
 149
 150       ;; Partially validate agent covered methods now that the
 151       ;; gnus-select-method is known.
 152
 153       (if gnus-agent
 154           ;; NOTE: This is here for one purpose only.  By validating
 155           ;; the current select method, it converts the old 5.10.3,
 156           ;; and earlier, format to the current format.  That enables
 157           ;; the agent code within gnus-open-server to function
 158           ;; correctly.
 159           (gnus-agent-read-servers-validate-native gnus-select-method))
 160
 161       (or
 162        ;; gnus-open-server-hook might have opened it
 163        (gnus-server-opened gnus-select-method)
 164        (gnus-open-server gnus-select-method)
 165        gnus-batch-mode
 166        (gnus-y-or-n-p
 167         (format
 168          "%s (%s) open error: '%s'.  Continue? "
 169          (car gnus-select-method) (cadr gnus-select-method)
 170          (gnus-status-message gnus-select-method)))
 171        (gnus-error 1 "Couldn't open server on %s"
 172                    (nth 1 gnus-select-method))))))
 173
 174 (defun gnus-check-group (group)
 175   "Try to make sure that the server where GROUP exists is alive."
 176   (let ((method (gnus-find-method-for-group group)))
 177     (or (gnus-server-opened method)
 178         (gnus-open-server method))))
 179
 180 (defun gnus-check-server (&optional method silent)
 181   "Check whether the connection to METHOD is down.
 182 If METHOD is nil, use `gnus-select-method'.
 183 If it is down, start it up (again)."
 184   (let ((method (or method gnus-select-method))
 185         result)
 186     ;; Transform virtual server names into select methods.
 187     (when (stringp method)
 188       (setq method (gnus-server-to-method method)))
 189     (if (gnus-server-opened method)
 190         ;; The stream is already opened.
 191         t
 192       ;; Open the server.
 193       (unless silent
 194         (gnus-message 5 "Opening %s server%s..." (car method)
 195                       (if (equal (nth 1 method) "") ""
 196                         (format " on %s" (nth 1 method)))))
 197       (gnus-run-hooks 'gnus-open-server-hook)
 198       (prog1
 199           (setq result (gnus-open-server method))
 200         (unless silent
 201           (gnus-message
 202            (if result 5 3)
 203            "Opening %s server%s...%s" (car method)
 204            (if (equal (nth 1 method) "") ""
 205              (format " on %s" (nth 1 method)))
 206            (if result
 207                "done"
 208              (format "failed: %s"
 209                      (nnheader-get-report-string (car method))))))))))
 210
 211 (defun gnus-get-function (method function &optional noerror)
 212   "Return a function symbol based on METHOD and FUNCTION."
 213   ;; Translate server names into methods.
 214   (unless method
 215     (error "Attempted use of a nil select method"))
 216   (when (stringp method)
 217     (setq method (gnus-server-to-method method)))
 218   ;; Check cache of constructed names.
 219   (let* ((method-sym (if gnus-agent
 220                          (inline (gnus-agent-get-function method))
 221                        (car method)))
 222          (method-fns (get method-sym 'gnus-method-functions))
 223          (func (let ((method-fnlist-elt (assq function method-fns)))
 224                  (unless method-fnlist-elt
 225                    (setq method-fnlist-elt
 226                          (cons function
 227                                (intern (format "%s-%s" method-sym function))))
 228                    (put method-sym 'gnus-method-functions
 229                         (cons method-fnlist-elt method-fns)))
 230                  (cdr method-fnlist-elt))))
 231     ;; Maybe complain if there is no function.
 232     (unless (fboundp func)
 233       (unless (car method)
 234         (error "Trying to require a method that doesn't exist"))
 235       (require (car method))
 236       (when (not (fboundp func))
 237         (if noerror
 238             (setq func nil)
 239           (error "No such function: %s" func))))
 240     func))
 241
 242 \f
 243 ;;;
 244 ;;; Interface functions to the backends.
 245 ;;;
 246
 247 (defun gnus-method-denied-p (method)
 248   (eq (nth 1 (assoc method gnus-opened-servers))
 249       'denied))
 250
 251 (defvar gnus-backend-trace nil)
 252 (defvar gnus-backend-trace-elapsed nil)
 253
 254 (defun gnus-backend-trace (type form)
 255   (when gnus-backend-trace
 256     (with-current-buffer (get-buffer-create "*gnus trace*")
 257       (buffer-disable-undo)
 258       (goto-char (point-max))
 259       (insert (format-time-string "%H:%M:%S")
 260               (format " %.2fs %s %S\n"
 261                       (if (numberp gnus-backend-trace-elapsed)
 262                           (- (float-time) gnus-backend-trace-elapsed)
 263                         0)
 264                       type form))
 265       (setq gnus-backend-trace-elapsed (float-time)))))
 266
 267 (defun gnus-open-server (gnus-command-method)
 268   "Open a connection to GNUS-COMMAND-METHOD."
 269   (when (stringp gnus-command-method)
 270     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 271   (gnus-backend-trace :opening gnus-command-method)
 272   (let ((elem (assoc gnus-command-method gnus-opened-servers))
 273         (server (gnus-method-to-server-name gnus-command-method)))
 274     ;; If this method was previously denied, we just return nil.
 275     (if (eq (nth 1 elem) 'denied)
 276         (progn
 277           (gnus-message
 278            1 "Server %s previously determined to be down; not retrying" server)
 279           nil)
 280       ;; Open the server.
 281       (let* ((open-server-function
 282               (gnus-get-function gnus-command-method 'open-server))
 283              (result
 284               (condition-case err
 285                   (funcall open-server-function
 286                            (nth 1 gnus-command-method)
 287                            (nthcdr 2 gnus-command-method))
 288                 (error
 289                  (gnus-message 1 "Unable to open server %s due to: %s"
 290                                server (error-message-string err))
 291                  nil)
 292                 (quit
 293                  (if debug-on-quit
 294                      (debug "Quit")
 295                    (gnus-message 1 "Quit trying to open server %s" server))
 296                  nil)))
 297              open-offline)
 298         ;; If this hasn't been opened before, we add it to the list.
 299         (unless elem
 300           (setq elem (list gnus-command-method nil)
 301                 gnus-opened-servers (cons elem gnus-opened-servers)))
 302         ;; Set the status of this server.
 303         (setcar
 304          (cdr elem)
 305          (cond (result
 306                 (if (eq open-server-function 'nnagent-open-server)
 307                     ;; The agent's backend has a "special" status
 308                     'offline
 309                   'ok))
 310                ((and gnus-agent
 311                      (gnus-agent-method-p gnus-command-method))
 312                 (cond
 313                  (gnus-server-unopen-status
 314                   ;; Set the server's status to the unopen
 315                   ;; status.  If that status is offline,
 316                   ;; recurse to open the agent's backend.
 317                   (setq open-offline (eq gnus-server-unopen-status 'offline))
 318                   gnus-server-unopen-status)
 319                  ((not gnus-batch-mode)
 320                   (setq open-offline t)
 321                   'offline)
 322                  (t
 323                   ;; This agentized server was still denied
 324                   'denied)))
 325                (t
 326                 ;; This unagentized server must be denied
 327                 'denied)))
 328
 329         ;; NOTE: I MUST set the server's status to offline before this
 330         ;; recursive call as this status will drive the
 331         ;; gnus-get-function (called above) to return the agent's
 332         ;; backend.
 333         (if open-offline
 334             ;; Recursively open this offline server to perform the
 335             ;; open-server function of the agent's backend.
 336             (let ((gnus-server-unopen-status 'denied))
 337               ;; Bind gnus-server-unopen-status to avoid recursively
 338               ;; prompting with "go offline?".  This is only a concern
 339               ;; when the agent's backend fails to open the server.
 340               (gnus-open-server gnus-command-method))
 341           (when (and (eq (cadr elem) 'ok) gnus-agent
 342                      (gnus-agent-method-p gnus-command-method))
 343             (save-excursion
 344               (gnus-agent-possibly-synchronize-flags-server
 345                gnus-command-method)))
 346           (gnus-backend-trace :opened gnus-command-method)
 347           result)))))
 348
 349 (defun gnus-close-server (gnus-command-method)
 350   "Close the connection to GNUS-COMMAND-METHOD."
 351   (when (stringp gnus-command-method)
 352     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 353   (funcall (gnus-get-function gnus-command-method 'close-server)
 354            (nth 1 gnus-command-method)))
 355
 356 (defun gnus-request-list (gnus-command-method)
 357   "Request the active 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)
 361            (nth 1 gnus-command-method)))
 362
 363 (defun gnus-finish-retrieve-group-infos (gnus-command-method infos data)
 364   "Read and update infos from GNUS-COMMAND-METHOD."
 365   (when (stringp gnus-command-method)
 366     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 367   (gnus-backend-trace :finishing gnus-command-method)
 368   (prog1
 369       (funcall (gnus-get-function gnus-command-method
 370                                   'finish-retrieve-group-infos)
 371                (nth 1 gnus-command-method)
 372                infos data)
 373     (gnus-backend-trace :finished gnus-command-method)))
 374
 375 (defun gnus-retrieve-group-data-early (gnus-command-method infos)
 376   "Start early async retrieval of data from GNUS-COMMAND-METHOD."
 377   (when (stringp gnus-command-method)
 378     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 379   (funcall (gnus-get-function gnus-command-method 'retrieve-group-data-early)
 380            (nth 1 gnus-command-method)
 381            infos))
 382
 383 (defun gnus-request-list-newsgroups (gnus-command-method)
 384   "Request the newsgroups file from GNUS-COMMAND-METHOD."
 385   (when (stringp gnus-command-method)
 386     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 387   (funcall (gnus-get-function gnus-command-method 'request-list-newsgroups)
 388            (nth 1 gnus-command-method)))
 389
 390 (defun gnus-request-newgroups (date gnus-command-method)
 391   "Request all new groups since DATE from GNUS-COMMAND-METHOD."
 392   (when (stringp gnus-command-method)
 393     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 394   (let ((func (gnus-get-function gnus-command-method 'request-newgroups t)))
 395     (when func
 396       (funcall func date (nth 1 gnus-command-method)))))
 397
 398 (defun gnus-request-regenerate (gnus-command-method)
 399   "Request a data generation 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-regenerate)
 403            (nth 1 gnus-command-method)))
 404
 405 (defun gnus-request-compact-group (group)
 406   (let* ((method (gnus-find-method-for-group group))
 407          (gnus-command-method method)
 408          (result
 409           (funcall (gnus-get-function gnus-command-method
 410                                       'request-compact-group)
 411                    (gnus-group-real-name group)
 412                    (nth 1 gnus-command-method) t)))
 413     result))
 414
 415 (defun gnus-request-compact (gnus-command-method)
 416   "Request groups compaction from GNUS-COMMAND-METHOD."
 417   (when (stringp gnus-command-method)
 418     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 419   (funcall (gnus-get-function gnus-command-method 'request-compact)
 420            (nth 1 gnus-command-method)))
 421
 422 (defun gnus-request-group (group &optional dont-check gnus-command-method info)
 423   "Request GROUP.  If DONT-CHECK, no information is required."
 424   (let ((gnus-command-method
 425          (or gnus-command-method (inline (gnus-find-method-for-group group)))))
 426     (when (stringp gnus-command-method)
 427       (setq gnus-command-method
 428             (inline (gnus-server-to-method gnus-command-method))))
 429     (funcall (inline (gnus-get-function gnus-command-method 'request-group))
 430              (gnus-group-real-name group) (nth 1 gnus-command-method)
 431              dont-check
 432              info)))
 433
 434 (defun gnus-request-group-description (group)
 435   "Request a description of GROUP."
 436   (let ((gnus-command-method (gnus-find-method-for-group group))
 437         (func 'request-group-description))
 438     (when (gnus-check-backend-function func group)
 439       (funcall (gnus-get-function gnus-command-method func)
 440                (gnus-group-real-name group) (nth 1 gnus-command-method)))))
 441
 442 (defun gnus-request-group-scan (group info)
 443   "Request that GROUP get a complete rescan."
 444   (let ((gnus-command-method (gnus-find-method-for-group group))
 445         (func 'request-group-scan))
 446     (when (gnus-check-backend-function func group)
 447       (funcall (gnus-get-function gnus-command-method func)
 448                (gnus-group-real-name group) (nth 1 gnus-command-method) info))))
 449
 450 (defun gnus-close-group (group)
 451   "Request the GROUP be closed."
 452   (let ((gnus-command-method (inline (gnus-find-method-for-group group))))
 453     (funcall (gnus-get-function gnus-command-method 'close-group)
 454              (gnus-group-real-name group) (nth 1 gnus-command-method))))
 455
 456 (defun gnus-retrieve-headers (articles group &optional fetch-old)
 457   "Request headers for ARTICLES in GROUP.
 458 If FETCH-OLD, retrieve all headers (or some subset thereof) in the group."
 459   (let ((gnus-command-method (gnus-find-method-for-group group)))
 460     (cond
 461      ((and gnus-use-cache (numberp (car articles)))
 462       (gnus-cache-retrieve-headers articles group fetch-old))
 463      ((and gnus-agent (gnus-online gnus-command-method)
 464            (gnus-agent-method-p gnus-command-method))
 465       (gnus-agent-retrieve-headers articles group fetch-old))
 466      (t
 467       (funcall (gnus-get-function gnus-command-method 'retrieve-headers)
 468                articles (gnus-group-real-name group)
 469                (nth 1 gnus-command-method) fetch-old)))))
 470
 471 (defun gnus-retrieve-articles (articles group)
 472   "Request ARTICLES in GROUP."
 473   (let ((gnus-command-method (gnus-find-method-for-group group)))
 474     (funcall (gnus-get-function gnus-command-method 'retrieve-articles)
 475              articles (gnus-group-real-name group)
 476              (nth 1 gnus-command-method))))
 477
 478 (defun gnus-retrieve-groups (groups gnus-command-method)
 479   "Request active information on GROUPS from GNUS-COMMAND-METHOD."
 480   (when (stringp gnus-command-method)
 481     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 482   (funcall (gnus-get-function gnus-command-method 'retrieve-groups)
 483            groups (nth 1 gnus-command-method)))
 484
 485 (defun gnus-request-type (group &optional article)
 486   "Return the type (`post' or `mail') of GROUP (and ARTICLE)."
 487   (let ((gnus-command-method (gnus-find-method-for-group group)))
 488     (if (not (gnus-check-backend-function
 489               'request-type (car gnus-command-method)))
 490         'unknown
 491       (funcall (gnus-get-function gnus-command-method 'request-type)
 492                (gnus-group-real-name group) article))))
 493
 494 (defun gnus-request-update-group-status (group status)
 495   "Change the status of a group.
 496 Valid statuses include `subscribe' and `unsubscribe'."
 497   (let ((gnus-command-method (gnus-find-method-for-group group)))
 498     (if (not (gnus-check-backend-function
 499               'request-update-group-status (car gnus-command-method)))
 500         nil
 501       (funcall
 502        (gnus-get-function gnus-command-method 'request-update-group-status)
 503        (gnus-group-real-name group) status
 504        (nth 1 gnus-command-method)))))
 505
 506 (defun gnus-request-set-mark (group action)
 507   "Set marks on articles in the back end."
 508   (let ((gnus-command-method (gnus-find-method-for-group group)))
 509     (if (not (gnus-check-backend-function
 510               'request-set-mark (car gnus-command-method)))
 511         action
 512       (funcall (gnus-get-function gnus-command-method 'request-set-mark)
 513                (gnus-group-real-name group) action
 514                (nth 1 gnus-command-method))
 515       (gnus-run-hook-with-args gnus-after-set-mark-hook group action))))
 516
 517 (defun gnus-request-update-mark (group article mark)
 518   "Allow the back end to change the mark the user tries to put on an article."
 519   (let ((gnus-command-method (gnus-find-method-for-group group)))
 520     (if (not (gnus-check-backend-function
 521               'request-update-mark (car gnus-command-method)))
 522         mark
 523       (gnus-run-hook-with-args gnus-before-update-mark-hook group article mark)
 524       (funcall (gnus-get-function gnus-command-method 'request-update-mark)
 525                (gnus-group-real-name group) article mark))))
 526
 527 (defun gnus-request-article (article group &optional buffer)
 528   "Request the ARTICLE in GROUP.
 529 ARTICLE can either be an article number or an article Message-ID.
 530 If BUFFER, insert the article in that group."
 531   (let ((gnus-command-method (gnus-find-method-for-group group)))
 532     (funcall (gnus-get-function gnus-command-method 'request-article)
 533              article (gnus-group-real-name group)
 534              (nth 1 gnus-command-method) buffer)))
 535
 536 (defun gnus-request-thread (header group)
 537   "Request the headers in the thread containing the article specified by HEADER."
 538   (let ((gnus-command-method (gnus-find-method-for-group group)))
 539     (funcall (gnus-get-function gnus-command-method 'request-thread)
 540              header
 541              (gnus-group-real-name group))))
 542
 543 (defun gnus-select-group-with-message-id (group message-id)
 544   "Activate and select GROUP with the given MESSAGE-ID selected.
 545 Returns the article number of the message.
 546
 547 If GROUP is not already selected, the message will be the only one in
 548 the group's summary.
 549 "
 550   ;; TODO: is there a way to know at this point whether the group will
 551   ;; be newly-selected?  If so we could clean up the logic at the end
 552   ;;
 553   ;; save the new group's display parameter, if any, so we
 554   ;; can replace it temporarily with zero.
 555   (let ((saved-display
 556          (gnus-group-get-parameter group 'display :allow-list)))
 557
 558     ;; Tell gnus we really don't want any articles
 559     (gnus-group-set-parameter group 'display 0)
 560
 561     (unwind-protect
 562         (gnus-summary-read-group-1
 563          group (not :show-all) :no-article (not :kill-buffer)
 564          ;; The combination of no-display and this dummy list of
 565          ;; articles to select somehow makes it possible to open a
 566          ;; group with no articles in it.  Black magic.
 567          :no-display '(-1); select-articles
 568          )
 569       ;; Restore the new group's display parameter
 570       (gnus-group-set-parameter group 'display saved-display)))
 571
 572   ;; The summary buffer was suppressed by :no-display above.
 573   ;; Create it now and insert the message
 574   (let ((group-is-new (gnus-summary-setup-buffer group)))
 575     (condition-case err
 576         (let ((article-number
 577                (gnus-summary-insert-subject message-id)))
 578           (unless article-number
 579             (signal 'error "message-id not in group"))
 580           (gnus-summary-select-article nil nil nil article-number)
 581           article-number)
 582       ;; Clean up the new summary and propagate the error
 583       (error (when group-is-new (gnus-summary-exit))
 584              (apply 'signal err)))))
 585
 586 (defun gnus-simplify-group-name (group)
 587   "Return the simplest representation of the name of GROUP.
 588 This is the string that Gnus uses to identify the group."
 589   (gnus-group-prefixed-name
 590    (gnus-group-real-name group)
 591    (gnus-group-method group)))
 592
 593 (defun gnus-warp-to-article ()
 594   "Look up the current article in the group where it originated.
 595 This command only makes sense for groups shows articles gathered
 596 from other groups -- for instance, search results and the like."
 597   (interactive)
 598   (let ((gnus-command-method
 599          (gnus-find-method-for-group gnus-newsgroup-name)))
 600     (or
 601      (when (gnus-check-backend-function
 602             'warp-to-article (car gnus-command-method))
 603        (funcall (gnus-get-function gnus-command-method 'warp-to-article)))
 604      (and (bound-and-true-p gnus-registry-enabled)
 605           (gnus-try-warping-via-registry)))))
 606
 607 (defun gnus-request-head (article group)
 608   "Request the head of ARTICLE in GROUP."
 609   (let* ((gnus-command-method (gnus-find-method-for-group group))
 610          (head (gnus-get-function gnus-command-method 'request-head t))
 611          res clean-up)
 612     (cond
 613      ;; Check the cache.
 614      ((and gnus-use-cache
 615            (numberp article)
 616            (gnus-cache-request-article article group))
 617       (setq res (cons group article)
 618             clean-up t))
 619      ;; Check the agent cache.
 620      ((gnus-agent-request-article article group)
 621       (setq res (cons group article)
 622             clean-up t))
 623      ;; Use `head' function.
 624      ((fboundp head)
 625       (setq res (funcall head article
 626                          (and (not gnus-override-method) (gnus-group-real-name group))
 627                          (nth 1 gnus-command-method))))
 628      ;; Use `article' function.
 629      (t
 630       (setq res (gnus-request-article article group)
 631             clean-up t)))
 632     (when clean-up
 633       (with-current-buffer nntp-server-buffer
 634         (goto-char (point-min))
 635         (when (search-forward "\n\n" nil t)
 636           (delete-region (1- (point)) (point-max)))
 637         (nnheader-fold-continuation-lines)))
 638     res))
 639
 640 (defun gnus-request-body (article group)
 641   "Request the body of ARTICLE in GROUP."
 642   (let* ((gnus-command-method (gnus-find-method-for-group group))
 643          (head (gnus-get-function gnus-command-method 'request-body t))
 644          res clean-up)
 645     (cond
 646      ;; Check the cache.
 647      ((and gnus-use-cache
 648            (numberp article)
 649            (gnus-cache-request-article article group))
 650       (setq res (cons group article)
 651             clean-up t))
 652      ;; Check the agent cache.
 653      ((gnus-agent-request-article article group)
 654       (setq res (cons group article)
 655             clean-up t))
 656      ;; Use `head' function.
 657      ((fboundp head)
 658       (setq res (funcall head article (gnus-group-real-name group)
 659                          (nth 1 gnus-command-method))))
 660      ;; Use `article' function.
 661      (t
 662       (setq res (gnus-request-article article group)
 663             clean-up t)))
 664     (when clean-up
 665       (with-current-buffer nntp-server-buffer
 666         (goto-char (point-min))
 667         (when (search-forward "\n\n" nil t)
 668           (delete-region (point-min) (1- (point))))))
 669     res))
 670
 671 (defun gnus-request-post (gnus-command-method)
 672   "Post the current buffer using GNUS-COMMAND-METHOD."
 673   (when (stringp gnus-command-method)
 674     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 675   (funcall (gnus-get-function gnus-command-method 'request-post)
 676            (nth 1 gnus-command-method)))
 677
 678 (defun gnus-request-expunge-group (group gnus-command-method)
 679   "Expunge GROUP, which is removing articles that have been marked as deleted."
 680   (when (stringp gnus-command-method)
 681     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 682   (funcall (gnus-get-function gnus-command-method 'request-expunge-group)
 683            (gnus-group-real-name group)
 684            (nth 1 gnus-command-method)))
 685
 686 (defun gnus-request-scan (group gnus-command-method)
 687   "Request a SCAN being performed in GROUP from GNUS-COMMAND-METHOD.
 688 If GROUP is nil, all groups on GNUS-COMMAND-METHOD are scanned."
 689   (let ((gnus-command-method
 690          (if group (gnus-find-method-for-group group) gnus-command-method))
 691         (gnus-inhibit-demon t)
 692         (mail-source-plugged gnus-plugged))
 693     (when (or gnus-plugged
 694               (not (gnus-agent-method-p gnus-command-method)))
 695       (setq gnus-internal-registry-spool-current-method gnus-command-method)
 696       (funcall (gnus-get-function gnus-command-method 'request-scan)
 697                (and group (gnus-group-real-name group))
 698                (nth 1 gnus-command-method)))))
 699
 700 (defun gnus-request-update-info (info gnus-command-method)
 701   (when (gnus-check-backend-function
 702          'request-update-info (car gnus-command-method))
 703     (when (stringp gnus-command-method)
 704       (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 705     (funcall (gnus-get-function gnus-command-method 'request-update-info)
 706              (gnus-group-real-name (gnus-info-group info)) info
 707              (nth 1 gnus-command-method))))
 708
 709 (defsubst gnus-request-marks (info gnus-command-method)
 710   "Request that GNUS-COMMAND-METHOD update INFO."
 711   (when (stringp gnus-command-method)
 712     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 713   (when (gnus-check-backend-function
 714          'request-marks (car gnus-command-method))
 715     (let ((group (gnus-info-group info)))
 716       (and (funcall (gnus-get-function gnus-command-method 'request-marks)
 717                     (gnus-group-real-name group)
 718                     info (nth 1 gnus-command-method))
 719            ;; If the minimum article number is greater than 1, then all
 720            ;; smaller article numbers are known not to exist; we'll
 721            ;; artificially add those to the 'read range.
 722            (let* ((active (gnus-active group))
 723                   (min (car active)))
 724              (when (> min 1)
 725                (let* ((range (if (= min 2) 1 (cons 1 (1- min))))
 726                       (read (gnus-info-read info))
 727                       (new-read (gnus-range-add read (list range))))
 728                  (gnus-info-set-read info new-read)))
 729              info)))))
 730
 731 (defun gnus-request-expire-articles (articles group &optional force)
 732   (let* ((gnus-command-method (gnus-find-method-for-group group))
 733          ;; Filter out any negative article numbers; they can't be
 734          ;; expired here.
 735          (articles
 736           (delq nil (mapcar (lambda (n) (and (>= n 0) n)) articles)))
 737          (gnus-inhibit-demon t)
 738          (not-deleted
 739           (funcall
 740            (gnus-get-function gnus-command-method 'request-expire-articles)
 741            articles (gnus-group-real-name group) (nth 1 gnus-command-method)
 742            force)))
 743     (when (and gnus-agent
 744                (gnus-agent-method-p gnus-command-method))
 745       (let ((expired-articles (gnus-sorted-difference articles not-deleted)))
 746         (when expired-articles
 747           (gnus-agent-expire expired-articles group 'force))))
 748     not-deleted))
 749
 750 (defun gnus-request-move-article (article group server accept-function
 751                                           &optional last move-is-internal)
 752   (let* ((gnus-command-method (gnus-find-method-for-group group))
 753          (result (funcall (gnus-get-function gnus-command-method
 754                                              'request-move-article)
 755                           article (gnus-group-real-name group)
 756                           (nth 1 gnus-command-method) accept-function
 757                           last move-is-internal)))
 758     (when (and result gnus-agent
 759                (gnus-agent-method-p gnus-command-method))
 760       (gnus-agent-unfetch-articles group (list article)))
 761     result))
 762
 763 (defun gnus-request-accept-article (group &optional gnus-command-method last
 764                                           no-encode)
 765   (when (stringp gnus-command-method)
 766     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 767   (when (and (not gnus-command-method)
 768              (stringp group))
 769     (setq gnus-command-method (or (gnus-find-method-for-group group)
 770                                   (gnus-group-name-to-method group))))
 771   (goto-char (point-max))
 772   ;; Make sure there's a newline at the end of the article.
 773   (unless (bolp)
 774     (insert "\n"))
 775   (unless no-encode
 776     (let ((message-options message-options))
 777       (message-options-set-recipient)
 778       (save-restriction
 779         (message-narrow-to-head)
 780         (let ((mail-parse-charset message-default-charset))
 781           (mail-encode-encoded-word-buffer)))
 782       (message-encode-message-body)))
 783   (let ((gnus-command-method (or gnus-command-method
 784                                  (gnus-find-method-for-group group)))
 785         (result
 786          (funcall
 787           (gnus-get-function gnus-command-method 'request-accept-article)
 788           (if (stringp group) (gnus-group-real-name group) group)
 789           (cadr gnus-command-method)
 790           last)))
 791     (when (and gnus-agent
 792                (gnus-agent-method-p gnus-command-method)
 793                (cdr result))
 794       (gnus-agent-regenerate-group group (list (cdr result))))
 795     result))
 796
 797 (defun gnus-request-replace-article (article group buffer &optional no-encode)
 798   (unless no-encode
 799     (let ((message-options message-options))
 800       (message-options-set-recipient)
 801       (save-restriction
 802         (message-narrow-to-head)
 803         (let ((mail-parse-charset message-default-charset))
 804           (mail-encode-encoded-word-buffer)))
 805       (message-encode-message-body)))
 806   (let* ((func (car (gnus-group-name-to-method group)))
 807          (result (funcall (intern (format "%s-request-replace-article" func))
 808                           article (gnus-group-real-name group) buffer)))
 809     (when (and gnus-agent (gnus-agent-method-p gnus-command-method))
 810       (gnus-agent-regenerate-group group (list article)))
 811     result))
 812
 813 (defun gnus-request-restore-buffer (article group)
 814   "Request a new buffer restored to the state of ARTICLE."
 815   (let ((gnus-command-method (gnus-find-method-for-group group)))
 816     (funcall (gnus-get-function gnus-command-method 'request-restore-buffer)
 817              article (gnus-group-real-name group)
 818              (nth 1 gnus-command-method))))
 819
 820 (defun gnus-request-create-group (group &optional gnus-command-method args)
 821   (when (stringp gnus-command-method)
 822     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 823   (let ((gnus-command-method
 824          (or gnus-command-method (gnus-find-method-for-group group))))
 825     (funcall (gnus-get-function gnus-command-method 'request-create-group)
 826              (gnus-group-real-name group) (nth 1 gnus-command-method) args)))
 827
 828 (defun gnus-request-delete-group (group &optional force)
 829   (let* ((gnus-command-method (gnus-find-method-for-group group))
 830          (result
 831           (funcall (gnus-get-function gnus-command-method 'request-delete-group)
 832                    (gnus-group-real-name group) force (nth 1 gnus-command-method))))
 833     (when result
 834       (gnus-cache-delete-group group)
 835       (gnus-agent-delete-group group))
 836     result))
 837
 838 (defun gnus-request-rename-group (group new-name)
 839   (let* ((gnus-command-method (gnus-find-method-for-group group))
 840          (result
 841           (funcall (gnus-get-function gnus-command-method 'request-rename-group)
 842                    (gnus-group-real-name group)
 843                    (gnus-group-real-name new-name) (nth 1 gnus-command-method))))
 844     (when result
 845       (gnus-cache-rename-group group new-name)
 846       (gnus-agent-rename-group group new-name))
 847     result))
 848
 849 (defun gnus-close-backends ()
 850   ;; Send a close request to all backends that support such a request.
 851   (let ((methods gnus-valid-select-methods)
 852         (gnus-inhibit-demon t)
 853         func gnus-command-method)
 854     (while (setq gnus-command-method (pop methods))
 855       (when (fboundp (setq func (intern
 856                                  (concat (car gnus-command-method)
 857                                          "-request-close"))))
 858         (funcall func)))))
 859
 860 (defun gnus-asynchronous-p (gnus-command-method)
 861   (let ((func (gnus-get-function gnus-command-method 'asynchronous-p t)))
 862     (when (fboundp func)
 863       (funcall func))))
 864
 865 (defun gnus-remove-denial (gnus-command-method)
 866   (when (stringp gnus-command-method)
 867     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 868   (let* ((elem (assoc gnus-command-method gnus-opened-servers))
 869          (status (cadr elem)))
 870     ;; If this hasn't been opened before, we add it to the list.
 871     (when (eq status 'denied)
 872       ;; Set the status of this server.
 873       (setcar (cdr elem) 'closed))))
 874
 875 (provide 'gnus-int)
 876
 877 ;;; gnus-int.el ends here