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emacs/lisp/gnus/gnus-demon.el
2009-01-05 03:18:22 +00:00

324 lines
11 KiB
EmacsLisp

;;; gnus-demon.el --- daemonic Gnus behavior
;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
;; 2005, 2006, 2007, 2008, 2009 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)
(require 'gnus-util)
(autoload 'parse-time-string "parse-time" nil nil)
(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 if Emacs has been idle for a while. 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-timer nil)
(defvar gnus-demon-idle-has-been-called nil)
(defvar gnus-demon-idle-time 0)
(defvar gnus-demon-handler-state nil)
(defvar gnus-demon-last-keys nil)
(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-pull function gnus-demon-handlers)
(unless no-init
(gnus-demon-init)))
(defun gnus-demon-init ()
"Initialize the Gnus daemon."
(interactive)
(gnus-demon-cancel)
(when gnus-demon-handlers
;; Set up the timer.
(setq gnus-demon-timer
(run-at-time
gnus-demon-timestep gnus-demon-timestep 'gnus-demon))
;; Reset control variables.
(setq gnus-demon-handler-state
(mapcar
(lambda (handler)
(list (car handler) (gnus-demon-time-to-step (nth 1 handler))
(nth 2 handler)))
gnus-demon-handlers))
(setq gnus-demon-idle-time 0)
(setq gnus-demon-idle-has-been-called nil)))
(gnus-add-shutdown 'gnus-demon-cancel 'gnus)
(defun gnus-demon-cancel ()
"Cancel any Gnus daemons."
(interactive)
(when gnus-demon-timer
(nnheader-cancel-timer gnus-demon-timer))
(setq gnus-demon-timer nil
gnus-demon-idle-has-been-called nil)
(condition-case ()
(nnheader-cancel-function-timers 'gnus-demon)
(error t)))
(defun gnus-demon-is-idle-p ()
"Whether Emacs is idle or not."
;; We do this simply by comparing the 100 most recent keystrokes
;; with the ones we had last time. If they are the same, one might
;; guess that Emacs is indeed idle. This only makes sense if one
;; calls this function seldom -- like once a minute, which is what
;; we do here.
(let ((keys (recent-keys)))
(or (equal keys gnus-demon-last-keys)
(progn
(setq gnus-demon-last-keys keys)
nil))))
(defun gnus-demon-time-to-step (time)
"Find out how many seconds to TIME, which is on the form \"17:43\"."
(if (not (stringp time))
time
(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)))))
(defun gnus-demon ()
"The Gnus daemon that takes care of running all Gnus handlers."
;; Increase or reset the time Emacs has been idle.
(if (gnus-demon-is-idle-p)
(incf gnus-demon-idle-time)
(setq gnus-demon-idle-time 0)
(setq gnus-demon-idle-has-been-called nil))
;; Disable all daemonic stuff if we're in the minibuffer
(when (and (not (window-minibuffer-p (selected-window)))
(not gnus-inhibit-demon))
;; Then we go through all the handler and call those that are
;; sufficiently ripe.
(let ((handlers gnus-demon-handler-state)
(gnus-inhibit-demon t)
;; Try to avoid dialog boxes, e.g. by Mailcrypt.
;; Unfortunately, Emacs 20's `message-or-box...' doesn't
;; obey `use-dialog-box'.
use-dialog-box (last-nonmenu-event 10)
handler time idle)
(while handlers
(setq handler (pop handlers))
(cond
((numberp (setq time (nth 1 handler)))
;; These handlers use a regular timeout mechanism. We decrease
;; the timer if it hasn't reached zero yet.
(unless (zerop time)
(setcar (nthcdr 1 handler) (decf time)))
(and (zerop time) ; If the timer now is zero...
;; Test for appropriate idleness
(progn
(setq idle (nth 2 handler))
(cond
((null idle) t) ; Don't care about idle.
((numberp idle) ; Numerical idle...
(< idle gnus-demon-idle-time)) ; Idle timed out.
(t (< 0 gnus-demon-idle-time)))) ; Or just need to be idle.
;; So we call the handler.
(gnus-with-local-quit
(ignore-errors (funcall (car handler)))
;; And reset the timer.
(setcar (nthcdr 1 handler)
(gnus-demon-time-to-step
(nth 1 (assq (car handler) gnus-demon-handlers)))))))
;; These are only supposed to be called when Emacs is idle.
((null (setq idle (nth 2 handler)))
;; We do nothing.
)
((and (not (numberp idle))
(gnus-demon-is-idle-p))
;; We want to call this handler each and every time that
;; Emacs is idle.
(gnus-with-local-quit
(ignore-errors (funcall (car handler)))))
(t
;; We want to call this handler only if Emacs has been idle
;; for a specified number of timesteps.
(and (not (memq (car handler) gnus-demon-idle-has-been-called))
(< idle gnus-demon-idle-time)
(gnus-demon-is-idle-p)
(gnus-with-local-quit
(ignore-errors (funcall (car handler)))
;; Make sure the handler won't be called once more in
;; this idle-cycle.
(push (car handler) gnus-demon-idle-has-been-called)))))))))
(defun gnus-demon-add-nocem ()
"Add daemonic NoCeM handling to Gnus."
(gnus-demon-add-handler 'gnus-demon-scan-nocem 60 30))
(defun gnus-demon-scan-nocem ()
"Scan NoCeM groups for NoCeM messages."
(save-window-excursion
(gnus-nocem-scan-groups)))
(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-connections 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
(save-excursion
(when (gnus-alive-p)
(save-excursion
(set-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)
;; arch-tag: 8dd5cd3d-6ae4-46b4-9b15-f5fca09fd392
;;; gnus-demon.el ends here