;;; gnus-demon.el --- daemonic Gnus behavior
;; Copyright (C) 1995-2013 Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; 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 3 of the License, 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. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;;; Code:
(eval-when-compile (require 'cl))
(require 'gnus)
(require 'gnus-int)
(require 'nnheader)
(require 'nntp)
(require 'nnmail)
(defgroup gnus-demon nil
"Demonic behavior."
:group 'gnus)
(defcustom gnus-demon-handlers nil
"Alist of daemonic handlers to be run at intervals.
Each handler is a list on the form
\(FUNCTION TIME IDLE)
FUNCTION is the function to be called. TIME is the number of
`gnus-demon-timestep's between each call.
If nil, never call. If t, call each `gnus-demon-timestep'.
If IDLE is t, only call each time Emacs has been idle for TIME.
If IDLE is a number, only call when Emacs has been idle more than
this number of `gnus-demon-timestep's.
If IDLE is nil, don't care about idleness.
If IDLE is a number and TIME is nil, then call once each time
Emacs has been idle for IDLE `gnus-demon-timestep's."
:group 'gnus-demon
:type '(repeat (list function
(choice :tag "Time"
(const :tag "never" nil)
(const :tag "one" t)
(integer :tag "steps" 1))
(choice :tag "Idle"
(const :tag "don't care" nil)
(const :tag "for a while" t)
(integer :tag "steps" 1)))))
(defcustom gnus-demon-timestep 60
"Number of seconds in each demon timestep."
:group 'gnus-demon
:type 'integer)
;;; Internal variables.
(defvar gnus-demon-timers nil
"Plist of idle timers which are running.")
(defvar gnus-inhibit-demon nil
"If non-nil, no daemonic function will be run.")
;;; Functions.
(defun gnus-demon-add-handler (function time idle)
"Add the handler FUNCTION to be run at TIME and IDLE."
;; First remove any old handlers that use this function.
(gnus-demon-remove-handler function)
;; Then add the new one.
(push (list function time idle) gnus-demon-handlers)
(gnus-demon-init))
(defun gnus-demon-remove-handler (function &optional no-init)
"Remove the handler FUNCTION from the list of handlers."
(gnus-alist-pull function gnus-demon-handlers)
(unless no-init
(gnus-demon-init)))
(defun gnus-demon-idle-since ()
"Return the number of seconds since when Emacs is idle."
(if (featurep 'xemacs)
(itimer-time-difference (current-time) last-command-event-time)
(float-time (or (current-idle-time)
'(0 0 0)))))
(defun gnus-demon-run-callback (func &optional idle time special)
"Run FUNC if Emacs has been idle for longer than IDLE seconds.
If not, and a TIME is given, restart a new idle timer, so FUNC
can be called at the next opportunity. Such a special idle run is
marked with SPECIAL."
(unless gnus-inhibit-demon
(block run-callback
(when (eq idle t)
(setq idle 0.001))
(cond (special
(setq gnus-demon-timers
(plist-put gnus-demon-timers func
(run-with-timer time time 'gnus-demon-run-callback
func idle time))))
((and idle (> idle (gnus-demon-idle-since)))
(when time
(nnheader-cancel-timer (plist-get gnus-demon-timers func))
(setq gnus-demon-timers
(plist-put gnus-demon-timers func
(run-with-idle-timer idle nil
'gnus-demon-run-callback
func idle time t))))
(return-from run-callback)))
(with-local-quit
(ignore-errors
(funcall func))))))
(defun gnus-demon-init ()
"Initialize the Gnus daemon."
(interactive)
(gnus-demon-cancel)
(dolist (handler gnus-demon-handlers)
;; Set up the timer.
(let* ((func (nth 0 handler))
(time (nth 1 handler))
(idle (nth 2 handler))
;; Compute time according with timestep.
;; If t, replace by 1
(time (cond ((eq time t)
gnus-demon-timestep)
((null time)
nil)
((stringp time)
(* (gnus-demon-time-to-step time) gnus-demon-timestep))
(t
(* time gnus-demon-timestep))))
(idle (cond ((numberp idle)
(* idle gnus-demon-timestep))
((and (eq idle t) (numberp time))
time)
(t
idle)))
(timer
(cond
;; (func nil number)
;; Only call when Emacs has been idle for `idle'
((and (null time) (numberp idle))
(run-with-idle-timer idle t 'gnus-demon-run-callback func))
;; (func number any)
;; Call every `time'
((integerp time)
(run-with-timer time time 'gnus-demon-run-callback
func idle time))
;; (func string any)
((stringp time)
(run-with-timer time (* 24 60 60) 'gnus-demon-run-callback
func idle)))))
(when timer
(setq gnus-demon-timers (plist-put gnus-demon-timers func timer))))))
(defun gnus-demon-time-to-step (time)
"Find out how many steps to TIME, which is on the form \"17:43\"."
(let* ((now (current-time))
;; obtain NOW as discrete components -- make a vector for speed
(nowParts (decode-time now))
;; obtain THEN as discrete components
(thenParts (parse-time-string time))
(thenHour (elt thenParts 2))
(thenMin (elt thenParts 1))
;; convert time as elements into number of seconds since EPOCH.
(then (encode-time 0
thenMin
thenHour
;; If THEN is earlier than NOW, make it
;; same time tomorrow. Doc for encode-time
;; says that this is OK.
(+ (elt nowParts 3)
(if (or (< thenHour (elt nowParts 2))
(and (= thenHour (elt nowParts 2))
(<= thenMin (elt nowParts 1))))
1 0))
(elt nowParts 4)
(elt nowParts 5)
(elt nowParts 6)
(elt nowParts 7)
(elt nowParts 8)))
;; calculate number of seconds between NOW and THEN
(diff (+ (* 65536 (- (car then) (car now)))
(- (cadr then) (cadr now)))))
;; return number of timesteps in the number of seconds
(round (/ diff gnus-demon-timestep))))
(gnus-add-shutdown 'gnus-demon-cancel 'gnus)
(defun gnus-demon-cancel ()
"Cancel any Gnus daemons."
(interactive)
(dotimes (i (/ (length gnus-demon-timers) 2))
(nnheader-cancel-timer (nth (1+ (* i 2)) gnus-demon-timers)))
(setq gnus-demon-timers nil))
(defun gnus-demon-add-disconnection ()
"Add daemonic server disconnection to Gnus."
(gnus-demon-add-handler 'gnus-demon-close-connections nil 30))
(defun gnus-demon-close-connections ()
(save-window-excursion
(gnus-close-backends)))
(defun gnus-demon-add-nntp-close-connection ()
"Add daemonic nntp server disconnection to Gnus.
If no commands have gone out via nntp during the last five
minutes, the connection is closed."
(gnus-demon-add-handler 'gnus-demon-nntp-close-connection 5 nil))
(defun gnus-demon-nntp-close-connection ()
(save-window-excursion
(when (time-less-p '(0 300) (time-since nntp-last-command-time))
(nntp-close-server))))
(defun gnus-demon-add-scanmail ()
"Add daemonic scanning of mail from the mail backends."
(gnus-demon-add-handler 'gnus-demon-scan-mail 120 60))
(defun gnus-demon-scan-mail ()
(save-window-excursion
(let ((servers gnus-opened-servers)
server
(nnmail-fetched-sources (list t)))
(while (setq server (car (pop servers)))
(and (gnus-check-backend-function 'request-scan (car server))
(or (gnus-server-opened server)
(gnus-open-server server))
(gnus-request-scan nil server))))))
(defun gnus-demon-add-rescan ()
"Add daemonic scanning of new articles from all backends."
(gnus-demon-add-handler 'gnus-demon-scan-news 120 60))
(defun gnus-demon-scan-news ()
(let ((win (current-window-configuration)))
(unwind-protect
(save-window-excursion
(when (gnus-alive-p)
(with-current-buffer gnus-group-buffer
(gnus-group-get-new-news))))
(set-window-configuration win))))
(defun gnus-demon-add-scan-timestamps ()
"Add daemonic updating of timestamps in empty newgroups."
(gnus-demon-add-handler 'gnus-demon-scan-timestamps nil 30))
(defun gnus-demon-scan-timestamps ()
"Set the timestamp on all newsgroups with no unread and no ticked articles."
(when (gnus-alive-p)
(let ((cur-time (current-time))
(newsrc (cdr gnus-newsrc-alist))
info group unread has-ticked)
(while (setq info (pop newsrc))
(setq group (gnus-info-group info)
unread (gnus-group-unread group)
has-ticked (cdr (assq 'tick (gnus-info-marks info))))
(when (and (numberp unread)
(= unread 0)
(not has-ticked))
(gnus-group-set-parameter group 'timestamp cur-time))))))
(provide 'gnus-demon)
;;; gnus-demon.el ends here