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-time-float (num)
  67   "Convert the float number of seconds since epoch to the list of 3 integers."
  68   (let* ((div (ash 1 16)) (1st (floor num div)))
  69     (list 1st (floor (- num (* (float div) 1st)))
  70           (round (* 10000000 (mod num 1))))))
  71
  72 (defun midnight-buffer-display-time (&optional buf)
  73   "Return the time-stamp of the given buffer, or current buffer, as float."
  74   (with-current-buffer (or buf (current-buffer))
  75     (when buffer-display-time (float-time buffer-display-time))))
  76
  77 ;;; clean-buffer-list stuff
  78
  79 (defcustom clean-buffer-list-delay-general 3
  80   "*The number of days before any buffer becomes eligible for autokilling.
  81 The autokilling is done by `clean-buffer-list' when is it in `midnight-hook'.
  82 Currently displayed and/or modified (unsaved) buffers, as well as buffers
  83 matching `clean-buffer-list-kill-never-buffer-names' and
  84 `clean-buffer-list-kill-never-regexps' are excluded."
  85   :type 'integer
  86   :group 'midnight)
  87
  88 (defcustom clean-buffer-list-delay-special 3600
  89   "*The number of seconds before some buffers become eligible for autokilling.
  90 Buffers matched by `clean-buffer-list-kill-regexps' and
  91 `clean-buffer-list-kill-buffer-names' are killed if they were last
  92 displayed more than this many seconds ago."
  93   :type 'integer
  94   :group 'midnight)
  95
  96 (defcustom clean-buffer-list-kill-regexps nil
  97   "*List of regexps saying which buffers will be killed at midnight.
  98 If buffer name matches a regexp in the list and the buffer was not displayed
  99 in the last `clean-buffer-list-delay-special' seconds, it is killed by
 100 `clean-buffer-list' when is it in `midnight-hook'.
 101 If a member of the list is a cons, its `car' is the regexp and its `cdr' is
 102 the number of seconds to use instead of `clean-buffer-list-delay-special'.
 103 See also `clean-buffer-list-kill-buffer-names',
 104 `clean-buffer-list-kill-never-regexps' and
 105 `clean-buffer-list-kill-never-buffer-names'."
 106   :type '(repeat (regexp :tag "Regexp matching Buffer Name"))
 107   :group 'midnight)
 108
 109 (defcustom clean-buffer-list-kill-buffer-names
 110     '("*Help*" "*Apropos*" "*Man " "*Buffer List*" "*Compile-Log*" "*info*"
 111       "*vc*" "*vc-diff*" "*diff*")
 112   "*List of strings saying which buffers will be killed at midnight.
 113 Buffers with names in this list, which were not displayed in the last
 114 `clean-buffer-list-delay-special' seconds, are killed by `clean-buffer-list'
 115 when is it in `midnight-hook'.
 116 If a member of the list is a cons, its `car' is the name and its `cdr' is
 117 the number of seconds to use instead of `clean-buffer-list-delay-special'.
 118 See also `clean-buffer-list-kill-regexps',
 119 `clean-buffer-list-kill-never-regexps' and
 120 `clean-buffer-list-kill-never-buffer-names'."
 121   :type '(repeat (string :tag "Buffer Name"))
 122   :group 'midnight)
 123
 124 (defcustom clean-buffer-list-kill-never-buffer-names
 125     '("*scratch*" "*Messages*")
 126   "*List of buffer names which will never be killed by `clean-buffer-list'.
 127 See also `clean-buffer-list-kill-never-regexps'.
 128 Note that this does override `clean-buffer-list-kill-regexps' and
 129 `clean-buffer-list-kill-buffer-names' so a buffer matching any of these
 130 two lists will NOT be killed if it is also present in this list."
 131   :type '(repeat (string :tag "Buffer Name"))
 132   :group 'midnight)
 133
 134
 135 (defcustom clean-buffer-list-kill-never-regexps '("^ \\*Minibuf-.*\\*$")
 136   "*List of regexp saying which buffers will never be killed at midnight.
 137 See also `clean-buffer-list-kill-never-buffer-names'.
 138 Killing is done by `clean-buffer-list'.
 139 Note that this does override `clean-buffer-list-kill-regexps' and
 140 `clean-buffer-list-kill-buffer-names' so a buffer matching any of these
 141 two lists will NOT be killed if it also matches anything in this list."
 142   :type '(repeat (regexp :tag "Regexp matching Buffer Name"))
 143   :group 'midnight)
 144
 145 (defun midnight-find (el ls test &optional key)
 146   "A stopgap solution to the absence of `find' in ELisp."
 147   (dolist (rr ls)
 148     (when (funcall test (if key (funcall key rr) rr) el)
 149       (return rr))))
 150
 151 (defun clean-buffer-list-delay (name)
 152   "Return the delay, in seconds, before killing a buffer named NAME.
 153 Uses `clean-buffer-list-kill-buffer-names', `clean-buffer-list-kill-regexps'
 154 `clean-buffer-list-delay-general' and `clean-buffer-list-delay-special'.
 155 Autokilling is done by `clean-buffer-list'."
 156   (or (assoc-default name clean-buffer-list-kill-buffer-names 'string=
 157                      clean-buffer-list-delay-special)
 158       (assoc-default name clean-buffer-list-kill-regexps 'string-match
 159                      clean-buffer-list-delay-special)
 160       (* clean-buffer-list-delay-general 24 60 60)))
 161
 162 ;;;###autoload
 163 (defun clean-buffer-list ()
 164   "Kill old buffers that have not been displayed recently.
 165 The relevant variables are `clean-buffer-list-delay-general',
 166 `clean-buffer-list-delay-special', `clean-buffer-list-kill-buffer-names',
 167 `clean-buffer-list-kill-never-buffer-names',
 168 `clean-buffer-list-kill-regexps' and
 169 `clean-buffer-list-kill-never-regexps'.
 170 While processing buffers, this procedure displays messages containing
 171 the current date/time, buffer name, how many seconds ago it was
 172 displayed (can be nil if the buffer was never displayed) and its
 173 lifetime, i.e., its \"age\" when it will be purged."
 174   (interactive)
 175   (let ((tm (float-time)) bts (ts (format-time-string "%Y-%m-%d %T"))
 176         (bufs (buffer-list)) buf delay cbld bn)
 177     (while (setq buf (pop bufs))
 178       (setq bts (midnight-buffer-display-time buf) bn (buffer-name buf)
 179             delay (if bts (- tm bts) 0) cbld (clean-buffer-list-delay bn))
 180       (message "[%s] `%s' [%s %d]" ts bn (if bts (round delay)) cbld)
 181       (unless (or (midnight-find bn clean-buffer-list-kill-never-regexps
 182                                  'string-match)
 183                   (midnight-find bn clean-buffer-list-kill-never-buffer-names
 184                                  'string-equal)
 185                   (get-buffer-process buf)
 186                   (and (buffer-file-name buf) (buffer-modified-p buf))
 187                   (get-buffer-window buf 'visible) (< delay cbld))
 188         (message "[%s] killing `%s'" ts bn)
 189         (kill-buffer buf)))))
 190
 191 ;;; midnight hook
 192
 193 (defvar midnight-period (* 24 60 60)
 194   "The number of seconds in a day--the delta for `midnight-timer'.")
 195
 196 (defcustom midnight-hook '(clean-buffer-list)
 197   "The hook run `midnight-delay' seconds after midnight every day.
 198 The default value is `clean-buffer-list'."
 199   :type 'hook
 200   :group 'midnight)
 201
 202 (defun midnight-next ()
 203   "Return the number of seconds till the next midnight."
 204   (multiple-value-bind (sec min hrs) (decode-time)
 205     (- (* 24 60 60) (* 60 60 hrs) (* 60 min) sec)))
 206
 207 (defvar midnight-timer nil
 208   "Timer running the `midnight-hook' `midnight-delay' seconds after midnight.
 209 Use `cancel-timer' to stop it and `midnight-delay-set' to change
 210 the time when it is run.")
 211
 212 ;;;###autoload
 213 (defun midnight-delay-set (symb tm)
 214   "Modify `midnight-timer' according to `midnight-delay'.
 215 Sets the first argument SYMB (which must be symbol `midnight-delay')
 216 to its second argument TM."
 217   (assert (eq symb 'midnight-delay) t
 218           "Illegal argument to `midnight-delay-set': `%s'" symb)
 219   (set symb tm)
 220   (when (timerp midnight-timer) (cancel-timer midnight-timer))
 221   (setq midnight-timer
 222         (run-at-time (if (numberp tm) (+ (midnight-next) tm) tm)
 223                      midnight-period 'run-hooks 'midnight-hook)))
 224
 225 (defcustom midnight-delay 3600
 226   "*The number of seconds after the midnight when the `midnight-timer' is run.
 227 You should set this variable before loading midnight.el, or
 228 set it by calling `midnight-delay-set', or use `custom'.
 229 If you wish, you can use a string instead, it will be passed as the
 230 first argument to `run-at-time'."
 231   :type 'sexp
 232   :set 'midnight-delay-set
 233   :group 'midnight)
 234
 235 (provide 'midnight)
 236
 237 ;;; midnight.el ends here