lisp/midnight.el

   1 ;;; midnight.el --- run something every midnight, e.g., kill old buffers.
   2
   3 ;;; Copyright (C) 1998 Free Software Foundation, Inc.
   4
   5 ;;; Author: Sam Steingold <sds@usa.net>
   6 ;;; Maintainer: Sam Steingold <sds@usa.net>
   7 ;;; Created: 1998-05-18
   8 ;;; Keywords: utilities
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; To use the file, put (require 'midnight) into your .emacs.  Then, at
  30 ;; midnight, Emacs will run the normal hook `midnight-hook'.  You can
  31 ;; put whatever you like there, say, `calendar'; by default there is
  32 ;; only one function there - `clean-buffer-list'. It will kill the
  33 ;; buffers matching `clean-buffer-list-kill-buffer-names' and
  34 ;; `clean-buffer-list-kill-regexps' and the buffers which where last
  35 ;; displayed more than `clean-buffer-list-delay-general' days ago,
  36 ;; keeping `clean-buffer-list-kill-never-buffer-names' and
  37 ;; `clean-buffer-list-kill-never-regexps'.
  38
  39 ;;; Code:
  40
  41 (eval-when-compile
  42  (require 'cl))
  43
  44 (require 'timer)
  45
  46 (defgroup midnight nil
  47   "Run something every day at midnight."
  48   :group 'calendar
  49   :version "20.3")
  50
  51 (defcustom midnight-mode nil
  52   "*Non-nil means run `midnight-hook' at midnight.
  53 Setting this variable outside customize has no effect;
  54 call `cancel-timer' or `timer-activate' on `midnight-timer' instead."
  55   :type 'boolean
  56   :group 'midnight
  57   :require 'midnight
  58   :initialize 'custom-initialize-default
  59   :set (lambda (symb val)
  60          (set symb val) (require 'midnight)
  61          (if val (timer-activate midnight-timer)
  62              (cancel-timer midnight-timer))))
  63
  64 ;;; time conversion
  65
  66 (defun midnight-float-time (&optional tm)
  67   "Convert `current-time' to a float number of seconds."
  68   (multiple-value-bind (s0 s1 s2) (or tm (current-time))
  69     (+ (* (float (ash 1 16)) s0) (float s1) (* 0.0000001 s2))))
  70
  71 (defun midnight-time-float (num)
  72   "Convert the float number of seconds since epoch to the list of 3 integers."
  73   (let* ((div (ash 1 16)) (1st (floor num div)))
  74     (list 1st (floor (- num (* (float div) 1st)))
  75           (round (* 10000000 (mod num 1))))))
  76
  77 (defun midnight-buffer-display-time (&optional buf)
  78   "Return the time-stamp of the given buffer, or current buffer, as float."
  79   (save-excursion
  80     (set-buffer (or buf (current-buffer)))
  81     (when buffer-display-time (midnight-float-time buffer-display-time))))
  82
  83 ;;; clean-buffer-list stuff
  84
  85 (defcustom clean-buffer-list-delay-general 3
  86   "*The number of days before any buffer becomes eligible for autokilling.
  87 The autokilling is done by `clean-buffer-list' when is it in `midnight-hook'.
  88 Currently displayed and/or modified (unsaved) buffers, as well as buffers
  89 matching `clean-buffer-list-kill-never-buffer-names' and
  90 `clean-buffer-list-kill-never-regexps' are excluded."
  91   :type 'integer
  92   :group 'midnight)
  93
  94 (defcustom clean-buffer-list-delay-special 3600
  95   "*The number of seconds before some buffers become eligible for autokilling.
  96 Buffers matched by `clean-buffer-list-kill-regexps' and
  97 `clean-buffer-list-kill-buffer-names' are killed if they were last
  98 displayed more than this many seconds ago."
  99   :type 'integer
 100   :group 'midnight)
 101
 102 (defcustom clean-buffer-list-kill-regexps nil
 103   "*List of regexps saying which buffers will be killed at midnight.
 104 If buffer name matches a regexp in the list and the buffer was not displayed
 105 in the last `clean-buffer-list-delay-special' seconds, it is killed by
 106 `clean-buffer-list' when is it in `midnight-hook'.
 107 If a member of the list is a cons, its `car' is the regexp and its `cdr' is
 108 the number of seconds to use instead of `clean-buffer-list-delay-special'.
 109 See also `clean-buffer-list-kill-buffer-names',
 110 `clean-buffer-list-kill-never-regexps' and
 111 `clean-buffer-list-kill-never-buffer-names'."
 112   :type '(repeat (regexp :tag "Regexp matching Buffer Name"))
 113   :group 'midnight)
 114
 115 (defcustom clean-buffer-list-kill-buffer-names
 116     '("*Help*" "*Apropos*" "*Man " "*Buffer List*" "*Compile-Log*" "*info*"
 117       "*vc*" "*vc-diff*" "*diff*")
 118   "*List of strings saying which buffers will be killed at midnight.
 119 Buffers with names in this list, which were not displayed in the last
 120 `clean-buffer-list-delay-special' seconds, are killed by `clean-buffer-list'
 121 when is it in `midnight-hook'.
 122 If a member of the list is a cons, its `car' is the name and its `cdr' is
 123 the number of seconds to use instead of `clean-buffer-list-delay-special'.
 124 See also `clean-buffer-list-kill-regexps',
 125 `clean-buffer-list-kill-never-regexps' and
 126 `clean-buffer-list-kill-never-buffer-names'."
 127   :type '(repeat (string :tag "Buffer Name"))
 128   :group 'midnight)
 129
 130 (defcustom clean-buffer-list-kill-never-buffer-names
 131     '("*scratch*" "*Messages*")
 132   "*List of buffer names which will never be killed by `clean-buffer-list'.
 133 See also `clean-buffer-list-kill-never-regexps'.
 134 Note that this does override `clean-buffer-list-kill-regexps' and
 135 `clean-buffer-list-kill-buffer-names' so a buffer matching any of these
 136 two lists will NOT be killed if it is also present in this list."
 137   :type '(repeat (string :tag "Buffer Name"))
 138   :group 'midnight)
 139
 140
 141 (defcustom clean-buffer-list-kill-never-regexps '("^ \*Minibuf-.*\*$")
 142   "*List of regexp saying which buffers will never be killed at midnight.
 143 See also `clean-buffer-list-kill-never-buffer-names'.
 144 Killing is done by `clean-buffer-list'.
 145 Note that this does override `clean-buffer-list-kill-regexps' and
 146 `clean-buffer-list-kill-buffer-names' so a buffer matching any of these
 147 two lists will NOT be killed if it also matches anything in this list."
 148   :type '(repeat (regexp :tag "Regexp matching Buffer Name"))
 149   :group 'midnight)
 150
 151 (defun midnight-find (el ls test &optional key)
 152   "A stopgap solution to the absence of `find' in ELisp."
 153   (dolist (rr ls)
 154     (when (funcall test el (if key (funcall key rr) rr))
 155       (return rr))))
 156
 157 (defun clean-buffer-list-delay (name)
 158   "Return the delay, in seconds, before killing a buffer named NAME.
 159 Uses `clean-buffer-list-kill-buffer-names', `clean-buffer-list-kill-regexps'
 160 `clean-buffer-list-delay-general' and `clean-buffer-list-delay-special'.
 161 Autokilling is done by `clean-buffer-list'."
 162   (or (assoc-default name clean-buffer-list-kill-buffer-names 'string=
 163                      clean-buffer-list-delay-special)
 164       (assoc-default name clean-buffer-list-kill-regexps 'string-match
 165                      clean-buffer-list-delay-special)
 166       (* clean-buffer-list-delay-general 24 60 60)))
 167
 168 ;;;###autoload
 169 (defun clean-buffer-list ()
 170   "Kill old buffers that have not been displayed recently.
 171 The relevant variables are `clean-buffer-list-delay-general',
 172 `clean-buffer-list-delay-special', `clean-buffer-list-kill-buffer-names',
 173 `clean-buffer-list-kill-never-buffer-names',
 174 `clean-buffer-list-kill-regexps' and
 175 `clean-buffer-list-kill-never-regexps'.
 176 While processing buffers, this procedure displays messages containing
 177 the current date/time, buffer name, how many seconds ago it was
 178 displayed (can be nil if the buffer was never displayed) and its
 179 lifetime, i.e., its \"age\" when it will be purged."
 180   (interactive)
 181   (let ((tm (midnight-float-time)) bts (ts (format-time-string "%Y-%m-%d %T"))
 182         (bufs (buffer-list)) buf delay cbld bn)
 183     (while (setq buf (pop bufs))
 184       (setq bts (midnight-buffer-display-time buf) bn (buffer-name buf)
 185             delay (if bts (- tm bts) 0) cbld (clean-buffer-list-delay bn))
 186       (message "[%s] `%s' [%s %d]" ts bn (if bts (round delay)) cbld)
 187       (unless (or (midnight-find bn clean-buffer-list-kill-never-regexps
 188                                  'string-match)
 189                   (midnight-find bn clean-buffer-list-kill-never-buffer-names
 190                                  'string-equal)
 191                   (get-buffer-process buf)
 192                   (and (buffer-file-name buf) (buffer-modified-p buf))
 193                   (get-buffer-window buf 'visible) (< delay cbld))
 194         (message "[%s] killing `%s'" ts bn)
 195         (kill-buffer buf)))))
 196
 197 ;;; midnight hook
 198
 199 (defvar midnight-period (* 24 60 60)
 200   "The number of seconds in a day--the delta for `midnight-timer'.")
 201
 202 (defcustom midnight-hook '(clean-buffer-list)
 203   "The hook run `midnight-delay' seconds after midnight every day.
 204 The default value is `clean-buffer-list'."
 205   :type 'hook
 206   :group 'midnight)
 207
 208 (defun midnight-next ()
 209   "Return the number of seconds till the next midnight."
 210   (multiple-value-bind (sec min hrs) (decode-time)
 211     (- (* 24 60 60) (* 60 60 hrs) (* 60 min) sec)))
 212
 213 (defvar midnight-timer nil
 214   "Timer running the `midnight-hook' `midnight-delay' seconds after midnight.
 215 Use `cancel-timer' to stop it and `midnight-delay-set' to change
 216 the time when it is run.")
 217
 218 ;;;###autoload
 219 (defun midnight-delay-set (symb tm)
 220   "Modify `midnight-timer' according to `midnight-delay'.
 221 Sets the first argument SYMB (which must be symbol `midnight-delay')
 222 to its second argument TM."
 223   (assert (eq symb 'midnight-delay) t
 224           "Illegal argument to `midnight-delay-set': `%s'" symb)
 225   (set symb tm)
 226   (when (timerp midnight-timer) (cancel-timer midnight-timer))
 227   (setq midnight-timer
 228         (run-at-time (if (numberp tm) (+ (midnight-next) tm) tm)
 229                      midnight-period 'run-hooks 'midnight-hook)))
 230
 231 (defcustom midnight-delay 3600
 232   "*The number of seconds after the midnight when the `midnight-timer' is run.
 233 You should set this variable before loading midnight.el, or
 234 set it by calling `midnight-delay-set', or use `custom'.
 235 If you wish, you can use a string instead, it will be passed as the
 236 first argument to `run-at-time'."
 237   :type 'sexp
 238   :set 'midnight-delay-set
 239   :group 'midnight)
 240
 241 (provide 'midnight)
 242
 243 ;;; midnight.el ends here