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emacs/lisp/gnus/gnus-int.el

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1997-04-16 22:13:18 +00:00
;;; gnus-int.el --- backend interface functions for Gnus
;; Copyright (C) 1996,97 Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
;; Keywords: news
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Commentary:
;;; Code:
(require 'gnus)
(defcustom gnus-open-server-hook nil
"Hook called just before opening connection to the news server."
:group 'gnus-start
:type 'hook)
;;;
;;; Server Communication
;;;
(defun gnus-start-news-server (&optional confirm)
"Open a method for getting news.
If CONFIRM is non-nil, the user will be asked for an NNTP server."
(let (how)
(if gnus-current-select-method
;; Stream is already opened.
nil
;; Open NNTP server.
(unless gnus-nntp-service
(setq gnus-nntp-server nil))
(when confirm
;; Read server name with completion.
(setq gnus-nntp-server
(completing-read "NNTP server: "
(mapcar (lambda (server) (list server))
(cons (list gnus-nntp-server)
gnus-secondary-servers))
nil nil gnus-nntp-server)))
(when (and gnus-nntp-server
(stringp gnus-nntp-server)
(not (string= gnus-nntp-server "")))
(setq gnus-select-method
(cond ((or (string= gnus-nntp-server "")
(string= gnus-nntp-server "::"))
(list 'nnspool (system-name)))
((string-match "^:" gnus-nntp-server)
(list 'nnmh gnus-nntp-server
(list 'nnmh-directory
(file-name-as-directory
(expand-file-name
(concat "~/" (substring
gnus-nntp-server 1)))))
(list 'nnmh-get-new-mail nil)))
(t
(list 'nntp gnus-nntp-server)))))
(setq how (car gnus-select-method))
(cond
((eq how 'nnspool)
(require 'nnspool)
(gnus-message 5 "Looking up local news spool..."))
((eq how 'nnmh)
(require 'nnmh)
(gnus-message 5 "Looking up mh spool..."))
(t
(require 'nntp)))
(setq gnus-current-select-method gnus-select-method)
(run-hooks 'gnus-open-server-hook)
(or
;; gnus-open-server-hook might have opened it
(gnus-server-opened gnus-select-method)
(gnus-open-server gnus-select-method)
(gnus-y-or-n-p
(format
"%s (%s) open error: '%s'. Continue? "
(car gnus-select-method) (cadr gnus-select-method)
(gnus-status-message gnus-select-method)))
(gnus-error 1 "Couldn't open server on %s"
(nth 1 gnus-select-method))))))
(defun gnus-check-group (group)
"Try to make sure that the server where GROUP exists is alive."
(let ((method (gnus-find-method-for-group group)))
(or (gnus-server-opened method)
(gnus-open-server method))))
(defun gnus-check-server (&optional method silent)
"Check whether the connection to METHOD is down.
If METHOD is nil, use `gnus-select-method'.
If it is down, start it up (again)."
(let ((method (or method gnus-select-method)))
;; Transform virtual server names into select methods.
(when (stringp method)
(setq method (gnus-server-to-method method)))
(if (gnus-server-opened method)
;; The stream is already opened.
t
;; Open the server.
(unless silent
(gnus-message 5 "Opening %s server%s..." (car method)
(if (equal (nth 1 method) "") ""
(format " on %s" (nth 1 method)))))
(run-hooks 'gnus-open-server-hook)
(prog1
(gnus-open-server method)
(unless silent
(message ""))))))
(defun gnus-get-function (method function &optional noerror)
"Return a function symbol based on METHOD and FUNCTION."
;; Translate server names into methods.
(unless method
(error "Attempted use of a nil select method"))
(when (stringp method)
(setq method (gnus-server-to-method method)))
(let ((func (intern (format "%s-%s" (car method) function))))
;; If the functions isn't bound, we require the backend in
;; question.
(unless (fboundp func)
(require (car method))
(when (and (not (fboundp func))
(not noerror))
;; This backend doesn't implement this function.
(error "No such function: %s" func)))
func))
;;;
;;; Interface functions to the backends.
;;;
(defun gnus-open-server (method)
"Open a connection to METHOD."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(let ((elem (assoc method gnus-opened-servers)))
;; If this method was previously denied, we just return nil.
(if (eq (nth 1 elem) 'denied)
(progn
(gnus-message 1 "Denied server")
nil)
;; Open the server.
(let ((result
(funcall (gnus-get-function method 'open-server)
(nth 1 method) (nthcdr 2 method))))
;; If this hasn't been opened before, we add it to the list.
(unless elem
(setq elem (list method nil)
gnus-opened-servers (cons elem gnus-opened-servers)))
;; Set the status of this server.
(setcar (cdr elem) (if result 'ok 'denied))
;; Return the result from the "open" call.
result))))
(defun gnus-close-server (method)
"Close the connection to METHOD."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(funcall (gnus-get-function method 'close-server) (nth 1 method)))
(defun gnus-request-list (method)
"Request the active file from METHOD."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(funcall (gnus-get-function method 'request-list) (nth 1 method)))
(defun gnus-request-list-newsgroups (method)
"Request the newsgroups file from METHOD."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(funcall (gnus-get-function method 'request-list-newsgroups) (nth 1 method)))
(defun gnus-request-newgroups (date method)
"Request all new groups since DATE from METHOD."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(let ((func (gnus-get-function method 'request-newgroups t)))
(when func
(funcall func date (nth 1 method)))))
(defun gnus-server-opened (method)
"Check whether a connection to METHOD has been opened."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(funcall (inline (gnus-get-function method 'server-opened)) (nth 1 method)))
(defun gnus-status-message (method)
"Return the status message from METHOD.
If METHOD is a string, it is interpreted as a group name. The method
this group uses will be queried."
(let ((method (if (stringp method) (gnus-find-method-for-group method)
method)))
(funcall (gnus-get-function method 'status-message) (nth 1 method))))
(defun gnus-request-regenerate (method)
"Request a data generation from METHOD."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(funcall (gnus-get-function method 'request-regenerate) (nth 1 method)))
(defun gnus-request-group (group &optional dont-check method)
"Request GROUP. If DONT-CHECK, no information is required."
(let ((method (or method (inline (gnus-find-method-for-group group)))))
(when (stringp method)
(setq method (inline (gnus-server-to-method method))))
(funcall (inline (gnus-get-function method 'request-group))
(gnus-group-real-name group) (nth 1 method) dont-check)))
(defun gnus-list-active-group (group)
"Request active information on GROUP."
(let ((method (gnus-find-method-for-group group))
(func 'list-active-group))
(when (gnus-check-backend-function func group)
(funcall (gnus-get-function method func)
(gnus-group-real-name group) (nth 1 method)))))
(defun gnus-request-group-description (group)
"Request a description of GROUP."
(let ((method (gnus-find-method-for-group group))
(func 'request-group-description))
(when (gnus-check-backend-function func group)
(funcall (gnus-get-function method func)
(gnus-group-real-name group) (nth 1 method)))))
(defun gnus-close-group (group)
"Request the GROUP be closed."
(let ((method (inline (gnus-find-method-for-group group))))
(funcall (gnus-get-function method 'close-group)
(gnus-group-real-name group) (nth 1 method))))
(defun gnus-retrieve-headers (articles group &optional fetch-old)
"Request headers for ARTICLES in GROUP.
If FETCH-OLD, retrieve all headers (or some subset thereof) in the group."
(let ((method (gnus-find-method-for-group group)))
(if (and gnus-use-cache (numberp (car articles)))
(gnus-cache-retrieve-headers articles group fetch-old)
(funcall (gnus-get-function method 'retrieve-headers)
articles (gnus-group-real-name group) (nth 1 method)
fetch-old))))
(defun gnus-retrieve-groups (groups method)
"Request active information on GROUPS from METHOD."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(funcall (gnus-get-function method 'retrieve-groups) groups (nth 1 method)))
(defun gnus-request-type (group &optional article)
"Return the type (`post' or `mail') of GROUP (and ARTICLE)."
(let ((method (gnus-find-method-for-group group)))
(if (not (gnus-check-backend-function 'request-type (car method)))
'unknown
(funcall (gnus-get-function method 'request-type)
(gnus-group-real-name group) article))))
(defun gnus-request-update-mark (group article mark)
"Return the type (`post' or `mail') of GROUP (and ARTICLE)."
(let ((method (gnus-find-method-for-group group)))
(if (not (gnus-check-backend-function 'request-update-mark (car method)))
mark
(funcall (gnus-get-function method 'request-update-mark)
(gnus-group-real-name group) article mark))))
(defun gnus-request-article (article group &optional buffer)
"Request the ARTICLE in GROUP.
ARTICLE can either be an article number or an article Message-ID.
If BUFFER, insert the article in that group."
(let ((method (gnus-find-method-for-group group)))
(funcall (gnus-get-function method 'request-article)
article (gnus-group-real-name group) (nth 1 method) buffer)))
(defun gnus-request-head (article group)
"Request the head of ARTICLE in GROUP."
(let* ((method (gnus-find-method-for-group group))
(head (gnus-get-function method 'request-head t))
res clean-up)
(cond
;; Check the cache.
((and gnus-use-cache
(numberp article)
(gnus-cache-request-article article group))
(setq res (cons group article)
clean-up t))
;; Use `head' function.
((fboundp head)
(setq res (funcall head article (gnus-group-real-name group)
(nth 1 method))))
;; Use `article' function.
(t
(setq res (gnus-request-article article group)
clean-up t)))
(when clean-up
(save-excursion
(set-buffer nntp-server-buffer)
(goto-char (point-min))
(when (search-forward "\n\n" nil t)
(delete-region (1- (point)) (point-max)))
(nnheader-fold-continuation-lines)))
res))
(defun gnus-request-body (article group)
"Request the body of ARTICLE in GROUP."
(let ((method (gnus-find-method-for-group group)))
(funcall (gnus-get-function method 'request-body)
article (gnus-group-real-name group) (nth 1 method))))
(defun gnus-request-post (method)
"Post the current buffer using METHOD."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(funcall (gnus-get-function method 'request-post) (nth 1 method)))
(defun gnus-request-scan (group method)
"Request a SCAN being performed in GROUP from METHOD.
If GROUP is nil, all groups on METHOD are scanned."
(let ((method (if group (gnus-find-method-for-group group) method))
(gnus-inhibit-demon t))
(funcall (gnus-get-function method 'request-scan)
(and group (gnus-group-real-name group)) (nth 1 method))))
(defsubst gnus-request-update-info (info method)
"Request that METHOD update INFO."
(when (stringp method)
(setq method (gnus-server-to-method method)))
(when (gnus-check-backend-function 'request-update-info (car method))
(funcall (gnus-get-function method 'request-update-info)
(gnus-group-real-name (gnus-info-group info))
info (nth 1 method))))
(defun gnus-request-expire-articles (articles group &optional force)
(let ((method (gnus-find-method-for-group group)))
(funcall (gnus-get-function method 'request-expire-articles)
articles (gnus-group-real-name group) (nth 1 method)
force)))
(defun gnus-request-move-article
(article group server accept-function &optional last)
(let ((method (gnus-find-method-for-group group)))
(funcall (gnus-get-function method 'request-move-article)
article (gnus-group-real-name group)
(nth 1 method) accept-function last)))
(defun gnus-request-accept-article (group method &optional last)
;; Make sure there's a newline at the end of the article.
(when (stringp method)
(setq method (gnus-server-to-method method)))
(when (and (not method)
(stringp group))
(setq method (gnus-group-name-to-method group)))
(goto-char (point-max))
(unless (bolp)
(insert "\n"))
(let ((func (car (or method (gnus-find-method-for-group group)))))
(funcall (intern (format "%s-request-accept-article" func))
(if (stringp group) (gnus-group-real-name group) group)
(cadr method)
last)))
(defun gnus-request-replace-article (article group buffer)
(let ((func (car (gnus-find-method-for-group group))))
(funcall (intern (format "%s-request-replace-article" func))
article (gnus-group-real-name group) buffer)))
(defun gnus-request-associate-buffer (group)
(let ((method (gnus-find-method-for-group group)))
(funcall (gnus-get-function method 'request-associate-buffer)
(gnus-group-real-name group))))
(defun gnus-request-restore-buffer (article group)
"Request a new buffer restored to the state of ARTICLE."
(let ((method (gnus-find-method-for-group group)))
(funcall (gnus-get-function method 'request-restore-buffer)
article (gnus-group-real-name group) (nth 1 method))))
(defun gnus-request-create-group (group &optional method args)
(when (stringp method)
(setq method (gnus-server-to-method method)))
(let ((method (or method (gnus-find-method-for-group group))))
(funcall (gnus-get-function method 'request-create-group)
(gnus-group-real-name group) (nth 1 method) args)))
(defun gnus-request-delete-group (group &optional force)
(let ((method (gnus-find-method-for-group group)))
(funcall (gnus-get-function method 'request-delete-group)
(gnus-group-real-name group) force (nth 1 method))))
(defun gnus-request-rename-group (group new-name)
(let ((method (gnus-find-method-for-group group)))
(funcall (gnus-get-function method 'request-rename-group)
(gnus-group-real-name group)
(gnus-group-real-name new-name) (nth 1 method))))
(defun gnus-close-backends ()
;; Send a close request to all backends that support such a request.
(let ((methods gnus-valid-select-methods)
(gnus-inhibit-demon t)
func method)
(while (setq method (pop methods))
(when (fboundp (setq func (intern
(concat (car method) "-request-close"))))
(funcall func)))))
(defun gnus-asynchronous-p (method)
(let ((func (gnus-get-function method 'asynchronous-p t)))
(when (fboundp func)
(funcall func))))
(defun gnus-remove-denial (method)
(when (stringp method)
(setq method (gnus-server-to-method method)))
(let* ((elem (assoc method gnus-opened-servers))
(status (cadr elem)))
;; If this hasn't been opened before, we add it to the list.
(when (eq status 'denied)
;; Set the status of this server.
(setcar (cdr elem) 'closed))))
(provide 'gnus-int)
;;; gnus-int.el ends here