lisp/midnight.el

   1 ;;; midnight.el --- run something every midnight, e.g., kill old buffers
   2
   3 ;; Copyright (C) 1998, 2001-2011 Free Software Foundation, Inc.
   4
   5 ;; Author: Sam Steingold <sds@gnu.org>
   6 ;; Maintainer: Sam Steingold <sds@gnu.org>
   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 3 of the License, or
  15 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; To use the file, put (require 'midnight) into your .emacs.  Then, at
  28 ;; midnight, Emacs will run the normal hook `midnight-hook'.  You can
  29 ;; put whatever you like there, say, `calendar'; by default there is
  30 ;; only one function there - `clean-buffer-list'. It will kill the
  31 ;; buffers matching `clean-buffer-list-kill-buffer-names' and
  32 ;; `clean-buffer-list-kill-regexps' and the buffers which where last
  33 ;; displayed more than `clean-buffer-list-delay-general' days ago,
  34 ;; keeping `clean-buffer-list-kill-never-buffer-names' and
  35 ;; `clean-buffer-list-kill-never-regexps'.
  36
  37 ;;; Code:
  38
  39 (eval-when-compile
  40  (require 'cl))
  41
  42 (defgroup midnight nil
  43   "Run something every day at midnight."
  44   :group 'calendar
  45   :version "20.3")
  46
  47 (defvar midnight-timer nil
  48   "Timer running the `midnight-hook' `midnight-delay' seconds after midnight.
  49 Use `cancel-timer' to stop it and `midnight-delay-set' to change
  50 the time when it is run.")
  51
  52 (defcustom midnight-mode nil
  53   "Non-nil means run `midnight-hook' at midnight.
  54 Setting this variable outside customize has no effect;
  55 call `cancel-timer' or `timer-activate' on `midnight-timer' instead."
  56   :type 'boolean
  57   :group 'midnight
  58   :require 'midnight
  59   :initialize 'custom-initialize-default
  60   :set (lambda (symb val)
  61          (set symb val) (require 'midnight)
  62          (if val (timer-activate midnight-timer)
  63              (cancel-timer midnight-timer))))
  64
  65 ;;; time conversion
  66
  67 (defun midnight-buffer-display-time (&optional buffer)
  68   "Return the time-stamp of BUFFER, or current buffer, as float."
  69   (with-current-buffer (or buffer (current-buffer))
  70     (when buffer-display-time (float-time buffer-display-time))))
  71
  72 ;;; clean-buffer-list stuff
  73
  74 (defcustom clean-buffer-list-delay-general 3
  75   "The number of days before any buffer becomes eligible for autokilling.
  76 The autokilling is done by `clean-buffer-list' when is it in `midnight-hook'.
  77 Currently displayed and/or modified (unsaved) buffers, as well as buffers
  78 matching `clean-buffer-list-kill-never-buffer-names' and
  79 `clean-buffer-list-kill-never-regexps' are excluded."
  80   :type 'integer
  81   :group 'midnight)
  82
  83 (defcustom clean-buffer-list-delay-special 3600
  84   "The number of seconds before some buffers become eligible for autokilling.
  85 Buffers matched by `clean-buffer-list-kill-regexps' and
  86 `clean-buffer-list-kill-buffer-names' are killed if they were last
  87 displayed more than this many seconds ago."
  88   :type 'integer
  89   :group 'midnight)
  90
  91 (defcustom clean-buffer-list-kill-regexps nil
  92   "List of regexps saying which buffers will be killed at midnight.
  93 If buffer name matches a regexp in the list and the buffer was not displayed
  94 in the last `clean-buffer-list-delay-special' seconds, it is killed by
  95 `clean-buffer-list' when is it in `midnight-hook'.
  96 If a member of the list is a cons, its `car' is the regexp and its `cdr' is
  97 the number of seconds to use instead of `clean-buffer-list-delay-special'.
  98 See also `clean-buffer-list-kill-buffer-names',
  99 `clean-buffer-list-kill-never-regexps' and
 100 `clean-buffer-list-kill-never-buffer-names'."
 101   :type '(repeat (regexp :tag "Regexp matching Buffer Name"))
 102   :group 'midnight)
 103
 104 (defcustom clean-buffer-list-kill-buffer-names
 105     '("*Help*" "*Apropos*" "*Man " "*Buffer List*" "*Compile-Log*" "*info*"
 106       "*vc*" "*vc-diff*" "*diff*")
 107   "List of strings saying which buffers will be killed at midnight.
 108 Buffers with names in this list, which were not displayed in the last
 109 `clean-buffer-list-delay-special' seconds, are killed by `clean-buffer-list'
 110 when is it in `midnight-hook'.
 111 If a member of the list is a cons, its `car' is the name and its `cdr' is
 112 the number of seconds to use instead of `clean-buffer-list-delay-special'.
 113 See also `clean-buffer-list-kill-regexps',
 114 `clean-buffer-list-kill-never-regexps' and
 115 `clean-buffer-list-kill-never-buffer-names'."
 116   :type '(repeat (string :tag "Buffer Name"))
 117   :group 'midnight)
 118
 119 (defcustom clean-buffer-list-kill-never-buffer-names
 120     '("*scratch*" "*Messages*")
 121   "List of buffer names which will never be killed by `clean-buffer-list'.
 122 See also `clean-buffer-list-kill-never-regexps'.
 123 Note that this does override `clean-buffer-list-kill-regexps' and
 124 `clean-buffer-list-kill-buffer-names' so a buffer matching any of these
 125 two lists will NOT be killed if it is also present in this list."
 126   :type '(repeat (string :tag "Buffer Name"))
 127   :group 'midnight)
 128
 129 (defcustom clean-buffer-list-kill-never-regexps '("^ \\*Minibuf-.*\\*$")
 130   "List of regexp saying which buffers will never be killed at midnight.
 131 See also `clean-buffer-list-kill-never-buffer-names'.
 132 Killing is done by `clean-buffer-list'.
 133 Note that this does override `clean-buffer-list-kill-regexps' and
 134 `clean-buffer-list-kill-buffer-names' so a buffer matching any of these
 135 two lists will NOT be killed if it also matches anything in this list."
 136   :type '(repeat (regexp :tag "Regexp matching Buffer Name"))
 137   :group 'midnight)
 138
 139 (defun midnight-find (el ls test &optional key)
 140   "A stopgap solution to the absence of `find' in ELisp."
 141   (dolist (rr ls)
 142     (when (funcall test (if key (funcall key rr) rr) el)
 143       (return rr))))
 144
 145 (defun clean-buffer-list-delay (name)
 146   "Return the delay, in seconds, before killing a buffer named NAME.
 147 Uses `clean-buffer-list-kill-buffer-names', `clean-buffer-list-kill-regexps'
 148 `clean-buffer-list-delay-general' and `clean-buffer-list-delay-special'.
 149 Autokilling is done by `clean-buffer-list'."
 150   (or (assoc-default name clean-buffer-list-kill-buffer-names 'string=
 151                      clean-buffer-list-delay-special)
 152       (assoc-default name clean-buffer-list-kill-regexps 'string-match
 153                      clean-buffer-list-delay-special)
 154       (* clean-buffer-list-delay-general 24 60 60)))
 155
 156 ;;;###autoload
 157 (defun clean-buffer-list ()
 158   "Kill old buffers that have not been displayed recently.
 159 The relevant variables are `clean-buffer-list-delay-general',
 160 `clean-buffer-list-delay-special', `clean-buffer-list-kill-buffer-names',
 161 `clean-buffer-list-kill-never-buffer-names',
 162 `clean-buffer-list-kill-regexps' and
 163 `clean-buffer-list-kill-never-regexps'.
 164 While processing buffers, this procedure displays messages containing
 165 the current date/time, buffer name, how many seconds ago it was
 166 displayed (can be nil if the buffer was never displayed) and its
 167 lifetime, i.e., its \"age\" when it will be purged."
 168   (interactive)
 169   (let ((tm (float-time)) bts (ts (format-time-string "%Y-%m-%d %T"))
 170         delay cbld bn)
 171     (dolist (buf (buffer-list))
 172       (when (buffer-live-p buf)
 173         (setq bts (midnight-buffer-display-time buf) bn (buffer-name buf)
 174               delay (if bts (- tm bts) 0) cbld (clean-buffer-list-delay bn))
 175         (message "[%s] `%s' [%s %d]" ts bn (if bts (round delay)) cbld)
 176         (unless (or (midnight-find bn clean-buffer-list-kill-never-regexps
 177                                    'string-match)
 178                     (midnight-find bn clean-buffer-list-kill-never-buffer-names
 179                                    'string-equal)
 180                     (get-buffer-process buf)
 181                     (and (buffer-file-name buf) (buffer-modified-p buf))
 182                     (get-buffer-window buf 'visible) (< delay cbld))
 183           (message "[%s] killing `%s'" ts bn)
 184           (kill-buffer buf))))))
 185
 186 ;;; midnight hook
 187
 188 (defvar midnight-period (* 24 60 60)
 189   "The number of seconds in a day--the delta for `midnight-timer'.")
 190
 191 (defcustom midnight-hook '(clean-buffer-list)
 192   "The hook run `midnight-delay' seconds after midnight every day.
 193 The default value is `clean-buffer-list'."
 194   :type 'hook
 195   :group 'midnight)
 196
 197 (defun midnight-next ()
 198   "Return the number of seconds till the next midnight."
 199   (multiple-value-bind (sec min hrs)
 200       (values-list (decode-time))
 201     (- (* 24 60 60) (* 60 60 hrs) (* 60 min) sec)))
 202
 203 ;;;###autoload
 204 (defun midnight-delay-set (symb tm)
 205   "Modify `midnight-timer' according to `midnight-delay'.
 206 Sets the first argument SYMB (which must be symbol `midnight-delay')
 207 to its second argument TM."
 208   (assert (eq symb 'midnight-delay) t
 209           "Invalid argument to `midnight-delay-set': `%s'")
 210   (set symb tm)
 211   (when (timerp midnight-timer) (cancel-timer midnight-timer))
 212   (setq midnight-timer
 213         (run-at-time (if (numberp tm) (+ (midnight-next) tm) tm)
 214                      midnight-period 'run-hooks 'midnight-hook)))
 215
 216 (defcustom midnight-delay 3600
 217   "The number of seconds after the midnight when the `midnight-timer' is run.
 218 You should set this variable before loading midnight.el, or
 219 set it by calling `midnight-delay-set', or use `custom'.
 220 If you wish, you can use a string instead, it will be passed as the
 221 first argument to `run-at-time'."
 222   :type 'sexp
 223   :set 'midnight-delay-set
 224   :group 'midnight)
 225
 226 (provide 'midnight)
 227
 228 ;;; midnight.el ends here