lisp/gnus/gnus-int.el

   1 ;;; gnus-int.el --- backend interface functions for Gnus
   2
   3 ;; Copyright (C) 1996-2013 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                                           gnus-secondary-servers)
 117                                     nil gnus-nntp-server)))
 118
 119       (when (and gnus-nntp-server
 120                  (stringp gnus-nntp-server)
 121                  (not (string= gnus-nntp-server "")))
 122         (setq gnus-select-method
 123               (cond ((or (string= gnus-nntp-server "")
 124                          (string= gnus-nntp-server "::"))
 125                      (list 'nnspool (system-name)))
 126                     ((string-match "^:" gnus-nntp-server)
 127                      (list 'nnmh gnus-nntp-server
 128                            (list 'nnmh-directory
 129                                  (file-name-as-directory
 130                                   (expand-file-name
 131                                    (substring gnus-nntp-server 1) "~/")))
 132                            (list 'nnmh-get-new-mail nil)))
 133                     (t
 134                      (list 'nntp gnus-nntp-server)))))
 135
 136       (setq how (car gnus-select-method))
 137       (cond
 138        ((eq how 'nnspool)
 139         (require 'nnspool)
 140         (gnus-message 5 "Looking up local news spool..."))
 141        ((eq how 'nnmh)
 142         (require 'nnmh)
 143         (gnus-message 5 "Looking up mh spool..."))
 144        (t
 145         (require 'nntp)))
 146       (setq gnus-current-select-method gnus-select-method)
 147       (gnus-run-hooks 'gnus-open-server-hook)
 148
 149       ;; Partially validate agent covered methods now that the
 150       ;; gnus-select-method is known.
 151
 152       (if gnus-agent
 153           ;; NOTE: This is here for one purpose only.  By validating
 154           ;; the current select method, it converts the old 5.10.3,
 155           ;; and earlier, format to the current format.  That enables
 156           ;; the agent code within gnus-open-server to function
 157           ;; correctly.
 158           (gnus-agent-read-servers-validate-native gnus-select-method))
 159
 160       (or
 161        ;; gnus-open-server-hook might have opened it
 162        (gnus-server-opened gnus-select-method)
 163        (gnus-open-server gnus-select-method)
 164        gnus-batch-mode
 165        (gnus-y-or-n-p
 166         (format
 167          "%s (%s) open error: '%s'.  Continue? "
 168          (car gnus-select-method) (cadr gnus-select-method)
 169          (gnus-status-message gnus-select-method)))
 170        (gnus-error 1 "Couldn't open server on %s"
 171                    (nth 1 gnus-select-method))))))
 172
 173 (defun gnus-check-group (group)
 174   "Try to make sure that the server where GROUP exists is alive."
 175   (let ((method (gnus-find-method-for-group group)))
 176     (or (gnus-server-opened method)
 177         (gnus-open-server method))))
 178
 179 (defun gnus-check-server (&optional method silent)
 180   "Check whether the connection to METHOD is down.
 181 If METHOD is nil, use `gnus-select-method'.
 182 If it is down, start it up (again)."
 183   (let ((method (or method gnus-select-method))
 184         result)
 185     ;; Transform virtual server names into select methods.
 186     (when (stringp method)
 187       (setq method (gnus-server-to-method method)))
 188     (if (gnus-server-opened method)
 189         ;; The stream is already opened.
 190         t
 191       ;; Open the server.
 192       (unless silent
 193         (gnus-message 5 "Opening %s server%s..." (car method)
 194                       (if (equal (nth 1 method) "") ""
 195                         (format " on %s" (nth 1 method)))))
 196       (gnus-run-hooks 'gnus-open-server-hook)
 197       (prog1
 198           (setq result (gnus-open-server method))
 199         (unless silent
 200           (gnus-message
 201            (if result 5 3)
 202            "Opening %s server%s...%s" (car method)
 203            (if (equal (nth 1 method) "") ""
 204              (format " on %s" (nth 1 method)))
 205            (if result
 206                "done"
 207              (format "failed: %s"
 208                      (nnheader-get-report-string (car method))))))))))
 209
 210 (defun gnus-get-function (method function &optional noerror)
 211   "Return a function symbol based on METHOD and FUNCTION."
 212   ;; Translate server names into methods.
 213   (unless method
 214     (error "Attempted use of a nil select method"))
 215   (when (stringp method)
 216     (setq method (gnus-server-to-method method)))
 217   ;; Check cache of constructed names.
 218   (let* ((method-sym (if gnus-agent
 219                          (inline (gnus-agent-get-function method))
 220                        (car method)))
 221          (method-fns (get method-sym 'gnus-method-functions))
 222          (func (let ((method-fnlist-elt (assq function method-fns)))
 223                  (unless method-fnlist-elt
 224                    (setq method-fnlist-elt
 225                          (cons function
 226                                (intern (format "%s-%s" method-sym function))))
 227                    (put method-sym 'gnus-method-functions
 228                         (cons method-fnlist-elt method-fns)))
 229                  (cdr method-fnlist-elt))))
 230     ;; Maybe complain if there is no function.
 231     (unless (fboundp func)
 232       (unless (car method)
 233         (error "Trying to require a method that doesn't exist"))
 234       (require (car method))
 235       (when (not (fboundp func))
 236         (if noerror
 237             (setq func nil)
 238           (error "No such function: %s" func))))
 239     func))
 240
 241 \f
 242 ;;;
 243 ;;; Interface functions to the backends.
 244 ;;;
 245
 246 (defun gnus-method-denied-p (method)
 247   (eq (nth 1 (assoc method gnus-opened-servers))
 248       'denied))
 249
 250 (defvar gnus-backend-trace nil)
 251 (defvar gnus-backend-trace-elapsed nil)
 252
 253 (defun gnus-backend-trace (type form)
 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 " %.2fs %s %S\n"
 260                       (if (numberp gnus-backend-trace-elapsed)
 261                           (- (float-time) gnus-backend-trace-elapsed)
 262                         0)
 263                       type form))
 264       (setq gnus-backend-trace-elapsed (float-time)))))
 265
 266 (defun gnus-open-server (gnus-command-method)
 267   "Open a connection to GNUS-COMMAND-METHOD."
 268   (when (stringp gnus-command-method)
 269     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 270   (gnus-backend-trace :opening gnus-command-method)
 271   (let ((elem (assoc gnus-command-method gnus-opened-servers))
 272         (server (gnus-method-to-server-name gnus-command-method)))
 273     ;; If this method was previously denied, we just return nil.
 274     (if (eq (nth 1 elem) 'denied)
 275         (progn
 276           (gnus-message
 277            1 "Server %s previously determined to be down; not retrying" server)
 278           nil)
 279       ;; Open the server.
 280       (let* ((open-server-function
 281               (gnus-get-function gnus-command-method 'open-server))
 282              (result
 283               (condition-case err
 284                   (funcall open-server-function
 285                            (nth 1 gnus-command-method)
 286                            (nthcdr 2 gnus-command-method))
 287                 (error
 288                  (gnus-message 1 "Unable to open server %s due to: %s"
 289                                server (error-message-string err))
 290                  nil)
 291                 (quit
 292                  (if debug-on-quit
 293                      (debug "Quit")
 294                    (gnus-message 1 "Quit trying to open server %s" server))
 295                  nil)))
 296              open-offline)
 297         ;; If this hasn't been opened before, we add it to the list.
 298         (unless elem
 299           (setq elem (list gnus-command-method nil)
 300                 gnus-opened-servers (cons elem gnus-opened-servers)))
 301         ;; Set the status of this server.
 302         (setcar
 303          (cdr elem)
 304          (cond (result
 305                 (if (eq open-server-function #'nnagent-open-server)
 306                     ;; The agent's backend has a "special" status
 307                     'offline
 308                   'ok))
 309                ((and gnus-agent
 310                      (gnus-agent-method-p gnus-command-method))
 311                 (cond
 312                  (gnus-server-unopen-status
 313                   ;; Set the server's status to the unopen
 314                   ;; status.  If that status is offline,
 315                   ;; recurse to open the agent's backend.
 316                   (setq open-offline (eq gnus-server-unopen-status 'offline))
 317                   gnus-server-unopen-status)
 318                  ((not gnus-batch-mode)
 319                   (setq open-offline t)
 320                   'offline)
 321                  (t
 322                   ;; This agentized server was still denied
 323                   'denied)))
 324                (t
 325                 ;; This unagentized server must be denied
 326                 'denied)))
 327
 328         ;; NOTE: I MUST set the server's status to offline before this
 329         ;; recursive call as this status will drive the
 330         ;; gnus-get-function (called above) to return the agent's
 331         ;; backend.
 332         (if open-offline
 333             ;; Recursively open this offline server to perform the
 334             ;; open-server function of the agent's backend.
 335             (let ((gnus-server-unopen-status 'denied))
 336               ;; Bind gnus-server-unopen-status to avoid recursively
 337               ;; prompting with "go offline?".  This is only a concern
 338               ;; when the agent's backend fails to open the server.
 339               (gnus-open-server gnus-command-method))
 340           (when (and (eq (cadr elem) 'ok) gnus-agent
 341                      (gnus-agent-method-p gnus-command-method))
 342             (save-excursion
 343               (gnus-agent-possibly-synchronize-flags-server
 344                gnus-command-method)))
 345           (gnus-backend-trace :opened gnus-command-method)
 346           result)))))
 347
 348 (defun gnus-close-server (gnus-command-method)
 349   "Close the connection to 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 'close-server)
 353            (nth 1 gnus-command-method)))
 354
 355 (defun gnus-request-list (gnus-command-method)
 356   "Request the active file from GNUS-COMMAND-METHOD."
 357   (when (stringp gnus-command-method)
 358     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 359   (funcall (gnus-get-function gnus-command-method 'request-list)
 360            (nth 1 gnus-command-method)))
 361
 362 (defun gnus-finish-retrieve-group-infos (gnus-command-method infos data)
 363   "Read and update infos from GNUS-COMMAND-METHOD."
 364   (when (stringp gnus-command-method)
 365     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 366   (gnus-backend-trace :finishing gnus-command-method)
 367   (prog1
 368       (funcall (gnus-get-function gnus-command-method
 369                                   'finish-retrieve-group-infos)
 370                (nth 1 gnus-command-method)
 371                infos data)
 372     (gnus-backend-trace :finished gnus-command-method)))
 373
 374 (defun gnus-retrieve-group-data-early (gnus-command-method infos)
 375   "Start early async retrieval of data from GNUS-COMMAND-METHOD."
 376   (when (stringp gnus-command-method)
 377     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 378   (funcall (gnus-get-function gnus-command-method 'retrieve-group-data-early)
 379            (nth 1 gnus-command-method)
 380            infos))
 381
 382 (defun gnus-request-list-newsgroups (gnus-command-method)
 383   "Request the newsgroups file from GNUS-COMMAND-METHOD."
 384   (when (stringp gnus-command-method)
 385     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 386   (funcall (gnus-get-function gnus-command-method 'request-list-newsgroups)
 387            (nth 1 gnus-command-method)))
 388
 389 (defun gnus-request-newgroups (date gnus-command-method)
 390   "Request all new groups since DATE from GNUS-COMMAND-METHOD."
 391   (when (stringp gnus-command-method)
 392     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 393   (let ((func (gnus-get-function gnus-command-method 'request-newgroups t)))
 394     (when func
 395       (funcall func date (nth 1 gnus-command-method)))))
 396
 397 (defun gnus-request-regenerate (gnus-command-method)
 398   "Request a data generation from GNUS-COMMAND-METHOD."
 399   (when (stringp gnus-command-method)
 400     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 401   (funcall (gnus-get-function gnus-command-method 'request-regenerate)
 402            (nth 1 gnus-command-method)))
 403
 404 (defun gnus-request-compact-group (group)
 405   (let* ((method (gnus-find-method-for-group group))
 406          (gnus-command-method method)
 407          (result
 408           (funcall (gnus-get-function gnus-command-method
 409                                       'request-compact-group)
 410                    (gnus-group-real-name group)
 411                    (nth 1 gnus-command-method) t)))
 412     result))
 413
 414 (defun gnus-request-compact (gnus-command-method)
 415   "Request groups compaction from GNUS-COMMAND-METHOD."
 416   (when (stringp gnus-command-method)
 417     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 418   (funcall (gnus-get-function gnus-command-method 'request-compact)
 419            (nth 1 gnus-command-method)))
 420
 421 (defun gnus-request-group (group &optional dont-check gnus-command-method info)
 422   "Request GROUP.  If DONT-CHECK, no information is required."
 423   (let ((gnus-command-method
 424          (or gnus-command-method (inline (gnus-find-method-for-group group)))))
 425     (when (stringp gnus-command-method)
 426       (setq gnus-command-method
 427             (inline (gnus-server-to-method gnus-command-method))))
 428     (funcall (inline (gnus-get-function gnus-command-method 'request-group))
 429              (gnus-group-real-name group) (nth 1 gnus-command-method)
 430              dont-check
 431              info)))
 432
 433 (defun gnus-request-group-description (group)
 434   "Request a description of GROUP."
 435   (let ((gnus-command-method (gnus-find-method-for-group group))
 436         (func 'request-group-description))
 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-select-group-with-message-id (group message-id)
 535   "Activate and select GROUP with the given MESSAGE-ID selected.
 536 Returns the article number of the message.
 537
 538 If GROUP is not already selected, the message will be the only one in
 539 the group's summary.
 540 "
 541   ;; TODO: is there a way to know at this point whether the group will
 542   ;; be newly-selected?  If so we could clean up the logic at the end
 543   ;;
 544   ;; save the new group's display parameter, if any, so we
 545   ;; can replace it temporarily with zero.
 546   (let ((saved-display
 547          (gnus-group-get-parameter group 'display :allow-list)))
 548
 549     ;; Tell gnus we really don't want any articles
 550     (gnus-group-set-parameter group 'display 0)
 551
 552     (unwind-protect
 553         (gnus-summary-read-group-1
 554          group (not :show-all) :no-article (not :kill-buffer)
 555          ;; The combination of no-display and this dummy list of
 556          ;; articles to select somehow makes it possible to open a
 557          ;; group with no articles in it.  Black magic.
 558          :no-display '(-1); select-articles
 559          )
 560       ;; Restore the new group's display parameter
 561       (gnus-group-set-parameter group 'display saved-display)))
 562
 563   ;; The summary buffer was suppressed by :no-display above.
 564   ;; Create it now and insert the message
 565   (let ((group-is-new (gnus-summary-setup-buffer group)))
 566     (condition-case err
 567         (let ((article-number
 568                (gnus-summary-insert-subject message-id)))
 569           (unless article-number
 570             (signal 'error "message-id not in group"))
 571           (gnus-summary-select-article nil nil nil article-number)
 572           article-number)
 573       ;; Clean up the new summary and propagate the error
 574       (error (when group-is-new (gnus-summary-exit))
 575              (apply 'signal err)))))
 576
 577 (defun gnus-simplify-group-name (group)
 578   "Return the simplest representation of the name of GROUP.
 579 This is the string that Gnus uses to identify the group."
 580   (gnus-group-prefixed-name
 581    (gnus-group-real-name group)
 582    (gnus-group-method group)))
 583
 584 (defun gnus-warp-to-article ()
 585   "Look up the current article in the group where it originated.
 586 This command only makes sense for groups shows articles gathered
 587 from other groups -- for instance, search results and the like."
 588   (interactive)
 589   (let ((gnus-command-method
 590          (gnus-find-method-for-group gnus-newsgroup-name)))
 591     (or
 592      (when (gnus-check-backend-function
 593             'warp-to-article (car gnus-command-method))
 594        (funcall (gnus-get-function gnus-command-method 'warp-to-article)))
 595      (and (bound-and-true-p gnus-registry-enabled)
 596           (gnus-try-warping-via-registry)))))
 597
 598 (defun gnus-request-head (article group)
 599   "Request the head of ARTICLE in GROUP."
 600   (let* ((gnus-command-method (gnus-find-method-for-group group))
 601          (head (gnus-get-function gnus-command-method 'request-head t))
 602          res clean-up)
 603     (cond
 604      ;; Check the cache.
 605      ((and gnus-use-cache
 606            (numberp article)
 607            (gnus-cache-request-article article group))
 608       (setq res (cons group article)
 609             clean-up t))
 610      ;; Check the agent cache.
 611      ((gnus-agent-request-article article group)
 612       (setq res (cons group article)
 613             clean-up t))
 614      ;; Use `head' function.
 615      ((fboundp head)
 616       (setq res (funcall head article
 617                          (and (not gnus-override-method) (gnus-group-real-name group))
 618                          (nth 1 gnus-command-method))))
 619      ;; Use `article' function.
 620      (t
 621       (setq res (gnus-request-article article group)
 622             clean-up t)))
 623     (when clean-up
 624       (with-current-buffer nntp-server-buffer
 625         (goto-char (point-min))
 626         (when (search-forward "\n\n" nil t)
 627           (delete-region (1- (point)) (point-max)))
 628         (nnheader-fold-continuation-lines)))
 629     res))
 630
 631 (defun gnus-request-body (article group)
 632   "Request the body of ARTICLE in GROUP."
 633   (let* ((gnus-command-method (gnus-find-method-for-group group))
 634          (head (gnus-get-function gnus-command-method 'request-body t))
 635          res clean-up)
 636     (cond
 637      ;; Check the cache.
 638      ((and gnus-use-cache
 639            (numberp article)
 640            (gnus-cache-request-article article group))
 641       (setq res (cons group article)
 642             clean-up t))
 643      ;; Check the agent cache.
 644      ((gnus-agent-request-article article group)
 645       (setq res (cons group article)
 646             clean-up t))
 647      ;; Use `head' function.
 648      ((fboundp head)
 649       (setq res (funcall head article (gnus-group-real-name group)
 650                          (nth 1 gnus-command-method))))
 651      ;; Use `article' function.
 652      (t
 653       (setq res (gnus-request-article article group)
 654             clean-up t)))
 655     (when clean-up
 656       (with-current-buffer nntp-server-buffer
 657         (goto-char (point-min))
 658         (when (search-forward "\n\n" nil t)
 659           (delete-region (point-min) (1- (point))))))
 660     res))
 661
 662 (defun gnus-request-post (gnus-command-method)
 663   "Post the current buffer using GNUS-COMMAND-METHOD."
 664   (when (stringp gnus-command-method)
 665     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 666   (funcall (gnus-get-function gnus-command-method 'request-post)
 667            (nth 1 gnus-command-method)))
 668
 669 (defun gnus-request-expunge-group (group gnus-command-method)
 670   "Expunge GROUP, which is removing articles that have been marked as deleted."
 671   (when (stringp gnus-command-method)
 672     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 673   (funcall (gnus-get-function gnus-command-method 'request-expunge-group)
 674            (gnus-group-real-name group)
 675            (nth 1 gnus-command-method)))
 676
 677 (defun gnus-request-scan (group gnus-command-method)
 678   "Request a SCAN being performed in GROUP from GNUS-COMMAND-METHOD.
 679 If GROUP is nil, all groups on GNUS-COMMAND-METHOD are scanned."
 680   (let ((gnus-command-method
 681          (if group (gnus-find-method-for-group group) gnus-command-method))
 682         (gnus-inhibit-demon t)
 683         (mail-source-plugged gnus-plugged))
 684     (when (or gnus-plugged
 685               (not (gnus-agent-method-p gnus-command-method)))
 686       (setq gnus-internal-registry-spool-current-method gnus-command-method)
 687       (funcall (gnus-get-function gnus-command-method 'request-scan)
 688                (and group (gnus-group-real-name group))
 689                (nth 1 gnus-command-method)))))
 690
 691 (defun gnus-request-update-info (info gnus-command-method)
 692   (when (gnus-check-backend-function
 693          'request-update-info (car gnus-command-method))
 694     (when (stringp gnus-command-method)
 695       (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 696     (funcall (gnus-get-function gnus-command-method 'request-update-info)
 697              (gnus-group-real-name (gnus-info-group info)) info
 698              (nth 1 gnus-command-method))))
 699
 700 (defsubst gnus-request-marks (info gnus-command-method)
 701   "Request that GNUS-COMMAND-METHOD update INFO."
 702   (when (stringp gnus-command-method)
 703     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 704   (when (gnus-check-backend-function
 705          'request-marks (car gnus-command-method))
 706     (let ((group (gnus-info-group info)))
 707       (and (funcall (gnus-get-function gnus-command-method 'request-marks)
 708                     (gnus-group-real-name group)
 709                     info (nth 1 gnus-command-method))
 710            ;; If the minimum article number is greater than 1, then all
 711            ;; smaller article numbers are known not to exist; we'll
 712            ;; artificially add those to the 'read range.
 713            (let* ((active (gnus-active group))
 714                   (min (car active)))
 715              (when (> min 1)
 716                (let* ((range (if (= min 2) 1 (cons 1 (1- min))))
 717                       (read (gnus-info-read info))
 718                       (new-read (gnus-range-add read (list range))))
 719                  (gnus-info-set-read info new-read)))
 720              info)))))
 721
 722 (defun gnus-request-expire-articles (articles group &optional force)
 723   (let* ((gnus-command-method (gnus-find-method-for-group group))
 724          ;; Filter out any negative article numbers; they can't be
 725          ;; expired here.
 726          (articles
 727           (delq nil (mapcar (lambda (n) (and (>= n 0) n)) articles)))
 728          (gnus-inhibit-demon t)
 729          (not-deleted
 730           (funcall
 731            (gnus-get-function gnus-command-method 'request-expire-articles)
 732            articles (gnus-group-real-name group) (nth 1 gnus-command-method)
 733            force)))
 734     (when (and gnus-agent
 735                (gnus-agent-method-p gnus-command-method))
 736       (let ((expired-articles (gnus-sorted-difference articles not-deleted)))
 737         (when expired-articles
 738           (gnus-agent-expire expired-articles group 'force))))
 739     not-deleted))
 740
 741 (defun gnus-request-move-article (article group server accept-function
 742                                           &optional last move-is-internal)
 743   (let* ((gnus-command-method (gnus-find-method-for-group group))
 744          (result (funcall (gnus-get-function gnus-command-method
 745                                              'request-move-article)
 746                           article (gnus-group-real-name group)
 747                           (nth 1 gnus-command-method) accept-function
 748                           last move-is-internal)))
 749     (when (and result gnus-agent
 750                (gnus-agent-method-p gnus-command-method))
 751       (gnus-agent-unfetch-articles group (list article)))
 752     result))
 753
 754 (defun gnus-request-accept-article (group &optional gnus-command-method last
 755                                           no-encode)
 756   ;; Make sure there's a newline at the end of the article.
 757   (when (stringp gnus-command-method)
 758     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 759   (when (and (not gnus-command-method)
 760              (stringp group))
 761     (setq gnus-command-method (or (gnus-find-method-for-group group)
 762                                   (gnus-group-name-to-method group))))
 763   (goto-char (point-max))
 764   (unless (bolp)
 765     (insert "\n"))
 766   (unless no-encode
 767     (let ((message-options message-options))
 768       (message-options-set-recipient)
 769       (save-restriction
 770         (message-narrow-to-head)
 771         (let ((mail-parse-charset message-default-charset))
 772           (mail-encode-encoded-word-buffer)))
 773       (message-encode-message-body)))
 774   (let ((gnus-command-method (or gnus-command-method
 775                                  (gnus-find-method-for-group group)))
 776         (result
 777          (funcall
 778           (gnus-get-function gnus-command-method 'request-accept-article)
 779           (if (stringp group) (gnus-group-real-name group) group)
 780           (cadr gnus-command-method)
 781           last)))
 782     (when (and gnus-agent
 783                (gnus-agent-method-p gnus-command-method)
 784                (cdr result))
 785       (gnus-agent-regenerate-group group (list (cdr result))))
 786     result))
 787
 788 (defun gnus-request-replace-article (article group buffer &optional no-encode)
 789   (unless no-encode
 790     (let ((message-options message-options))
 791       (message-options-set-recipient)
 792       (save-restriction
 793         (message-narrow-to-head)
 794         (let ((mail-parse-charset message-default-charset))
 795           (mail-encode-encoded-word-buffer)))
 796       (message-encode-message-body)))
 797   (let* ((func (car (gnus-group-name-to-method group)))
 798          (result (funcall (intern (format "%s-request-replace-article" func))
 799                           article (gnus-group-real-name group) buffer)))
 800     (when (and gnus-agent (gnus-agent-method-p gnus-command-method))
 801       (gnus-agent-regenerate-group group (list article)))
 802     result))
 803
 804 (defun gnus-request-restore-buffer (article group)
 805   "Request a new buffer restored to the state of ARTICLE."
 806   (let ((gnus-command-method (gnus-find-method-for-group group)))
 807     (funcall (gnus-get-function gnus-command-method 'request-restore-buffer)
 808              article (gnus-group-real-name group)
 809              (nth 1 gnus-command-method))))
 810
 811 (defun gnus-request-create-group (group &optional gnus-command-method args)
 812   (when (stringp gnus-command-method)
 813     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 814   (let ((gnus-command-method
 815          (or gnus-command-method (gnus-find-method-for-group group))))
 816     (funcall (gnus-get-function gnus-command-method 'request-create-group)
 817              (gnus-group-real-name group) (nth 1 gnus-command-method) args)))
 818
 819 (defun gnus-request-delete-group (group &optional force)
 820   (let* ((gnus-command-method (gnus-find-method-for-group group))
 821          (result
 822           (funcall (gnus-get-function gnus-command-method 'request-delete-group)
 823                    (gnus-group-real-name group) force (nth 1 gnus-command-method))))
 824     (when result
 825       (gnus-cache-delete-group group)
 826       (gnus-agent-delete-group group))
 827     result))
 828
 829 (defun gnus-request-rename-group (group new-name)
 830   (let* ((gnus-command-method (gnus-find-method-for-group group))
 831          (result
 832           (funcall (gnus-get-function gnus-command-method 'request-rename-group)
 833                    (gnus-group-real-name group)
 834                    (gnus-group-real-name new-name) (nth 1 gnus-command-method))))
 835     (when result
 836       (gnus-cache-rename-group group new-name)
 837       (gnus-agent-rename-group group new-name))
 838     result))
 839
 840 (defun gnus-close-backends ()
 841   ;; Send a close request to all backends that support such a request.
 842   (let ((methods gnus-valid-select-methods)
 843         (gnus-inhibit-demon t)
 844         func gnus-command-method)
 845     (while (setq gnus-command-method (pop methods))
 846       (when (fboundp (setq func (intern
 847                                  (concat (car gnus-command-method)
 848                                          "-request-close"))))
 849         (funcall func)))))
 850
 851 (defun gnus-asynchronous-p (gnus-command-method)
 852   (let ((func (gnus-get-function gnus-command-method 'asynchronous-p t)))
 853     (when (fboundp func)
 854       (funcall func))))
 855
 856 (defun gnus-remove-denial (gnus-command-method)
 857   (when (stringp gnus-command-method)
 858     (setq gnus-command-method (gnus-server-to-method gnus-command-method)))
 859   (let* ((elem (assoc gnus-command-method gnus-opened-servers))
 860          (status (cadr elem)))
 861     ;; If this hasn't been opened before, we add it to the list.
 862     (when (eq status 'denied)
 863       ;; Set the status of this server.
 864       (setcar (cdr elem) 'closed))))
 865
 866 (provide 'gnus-int)
 867
 868 ;;; gnus-int.el ends here