lisp/midnight.el

   1 ;;; midnight.el --- run something every midnight, e.g., kill old buffers
   2
   3 ;; Copyright (C) 1998, 2001-2014 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 (require 'cl-lib))
  40
  41 (defgroup midnight nil
  42   "Run something every day at midnight."
  43   :group 'calendar
  44   :version "20.3")
  45
  46 (defvar midnight-timer nil
  47   "Timer running the `midnight-hook' `midnight-delay' seconds after midnight.
  48 Use `cancel-timer' to stop it and `midnight-delay-set' to change
  49 the time when it is run.")
  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-buffer-display-time (&optional buffer)
  67   "Return the time-stamp of BUFFER, or current buffer, as float."
  68   (with-current-buffer (or buffer (current-buffer))
  69     (when buffer-display-time (float-time buffer-display-time))))
  70
  71 ;;; clean-buffer-list stuff
  72
  73 (defcustom clean-buffer-list-delay-general 3
  74   "The number of days before any buffer becomes eligible for autokilling.
  75 The autokilling is done by `clean-buffer-list' when is it in `midnight-hook'.
  76 Currently displayed and/or modified (unsaved) buffers, as well as buffers
  77 matching `clean-buffer-list-kill-never-buffer-names' and
  78 `clean-buffer-list-kill-never-regexps' are excluded."
  79   :type 'integer
  80   :group 'midnight)
  81
  82 (defcustom clean-buffer-list-delay-special 3600
  83   "The number of seconds before some buffers become eligible for autokilling.
  84 Buffers matched by `clean-buffer-list-kill-regexps' and
  85 `clean-buffer-list-kill-buffer-names' are killed if they were last
  86 displayed more than this many seconds ago."
  87   :type 'integer
  88   :group 'midnight)
  89
  90 (defcustom clean-buffer-list-kill-regexps '("^\\*Man ")
  91   "List of regexps saying which buffers will be killed at midnight.
  92 If buffer name matches a regexp in the list and the buffer was not displayed
  93 in the last `clean-buffer-list-delay-special' seconds, it is killed by
  94 `clean-buffer-list' when is it in `midnight-hook'.
  95 If a member of the list is a cons, its `car' is the regexp and its `cdr' is
  96 the number of seconds to use instead of `clean-buffer-list-delay-special'.
  97 See also `clean-buffer-list-kill-buffer-names',
  98 `clean-buffer-list-kill-never-regexps' and
  99 `clean-buffer-list-kill-never-buffer-names'."
 100   :type '(repeat (regexp :tag "Regexp matching Buffer Name"))
 101   :group 'midnight)
 102
 103 (defcustom clean-buffer-list-kill-buffer-names
 104     '("*Help*" "*Apropos*" "*Buffer List*" "*Compile-Log*" "*info*"
 105       "*vc*" "*vc-diff*" "*diff*")
 106   "List of strings saying which buffers will be killed at midnight.
 107 Buffers with names in this list, which were not displayed in the last
 108 `clean-buffer-list-delay-special' seconds, are killed by `clean-buffer-list'
 109 when is it in `midnight-hook'.
 110 If a member of the list is a cons, its `car' is the name and its `cdr' is
 111 the number of seconds to use instead of `clean-buffer-list-delay-special'.
 112 See also `clean-buffer-list-kill-regexps',
 113 `clean-buffer-list-kill-never-regexps' and
 114 `clean-buffer-list-kill-never-buffer-names'."
 115   :type '(repeat (string :tag "Buffer Name"))
 116   :group 'midnight)
 117
 118 (defcustom clean-buffer-list-kill-never-buffer-names
 119     '("*scratch*" "*Messages*")
 120   "List of buffer names which will never be killed by `clean-buffer-list'.
 121 See also `clean-buffer-list-kill-never-regexps'.
 122 Note that this does override `clean-buffer-list-kill-regexps' and
 123 `clean-buffer-list-kill-buffer-names' so a buffer matching any of these
 124 two lists will NOT be killed if it is also present in this list."
 125   :type '(repeat (string :tag "Buffer Name"))
 126   :group 'midnight)
 127
 128 (defcustom clean-buffer-list-kill-never-regexps '("^ \\*Minibuf-.*\\*$")
 129   "List of regexp saying which buffers will never be killed at midnight.
 130 See also `clean-buffer-list-kill-never-buffer-names'.
 131 Killing is done by `clean-buffer-list'.
 132 Note that this does override `clean-buffer-list-kill-regexps' and
 133 `clean-buffer-list-kill-buffer-names' so a buffer matching any of these
 134 two lists will NOT be killed if it also matches anything in this list."
 135   :type '(repeat (regexp :tag "Regexp matching Buffer Name"))
 136   :group 'midnight)
 137
 138 (defun midnight-find (el ls test &optional key)
 139   "A stopgap solution to the absence of `find' in ELisp."
 140   (cl-dolist (rr ls)
 141     (when (funcall test (if key (funcall key rr) rr) el)
 142       (cl-return rr))))
 143
 144 (defun clean-buffer-list-delay (name)
 145   "Return the delay, in seconds, before killing a buffer named NAME.
 146 Uses `clean-buffer-list-kill-buffer-names', `clean-buffer-list-kill-regexps'
 147 `clean-buffer-list-delay-general' and `clean-buffer-list-delay-special'.
 148 Autokilling is done by `clean-buffer-list'."
 149   (or (assoc-default name clean-buffer-list-kill-buffer-names 'string=
 150                      clean-buffer-list-delay-special)
 151       (assoc-default name clean-buffer-list-kill-regexps 'string-match
 152                      clean-buffer-list-delay-special)
 153       (* clean-buffer-list-delay-general 24 60 60)))
 154
 155 ;;;###autoload
 156 (defun clean-buffer-list ()
 157   "Kill old buffers that have not been displayed recently.
 158 The relevant variables are `clean-buffer-list-delay-general',
 159 `clean-buffer-list-delay-special', `clean-buffer-list-kill-buffer-names',
 160 `clean-buffer-list-kill-never-buffer-names',
 161 `clean-buffer-list-kill-regexps' and
 162 `clean-buffer-list-kill-never-regexps'.
 163 While processing buffers, this procedure displays messages containing
 164 the current date/time, buffer name, how many seconds ago it was
 165 displayed (can be nil if the buffer was never displayed) and its
 166 lifetime, i.e., its \"age\" when it will be purged."
 167   (interactive)
 168   (let ((tm (float-time)) bts (ts (format-time-string "%Y-%m-%d %T"))
 169         delay cbld bn)
 170     (dolist (buf (buffer-list))
 171       (when (buffer-live-p buf)
 172         (setq bts (midnight-buffer-display-time buf) bn (buffer-name buf)
 173               delay (if bts (- tm bts) 0) cbld (clean-buffer-list-delay bn))
 174         (message "[%s] `%s' [%s %d]" ts bn (if bts (round delay)) cbld)
 175         (unless (or (midnight-find bn clean-buffer-list-kill-never-regexps
 176                                    'string-match)
 177                     (midnight-find bn clean-buffer-list-kill-never-buffer-names
 178                                    'string-equal)
 179                     (get-buffer-process buf)
 180                     (and (buffer-file-name buf) (buffer-modified-p buf))
 181                     (get-buffer-window buf 'visible) (< delay cbld))
 182           (message "[%s] killing `%s'" ts bn)
 183           (kill-buffer buf))))))
 184
 185 ;;; midnight hook
 186
 187 (defvar midnight-period (* 24 60 60)
 188   "The number of seconds in a day--the delta for `midnight-timer'.")
 189
 190 (defcustom midnight-hook '(clean-buffer-list)
 191   "The hook run `midnight-delay' seconds after midnight every day.
 192 The default value is `clean-buffer-list'."
 193   :type 'hook
 194   :group 'midnight)
 195
 196 (defun midnight-next ()
 197   "Return the number of seconds till the next midnight."
 198   (pcase-let ((`(,sec ,min ,hrs) (decode-time)))
 199     (- (* 24 60 60) (* 60 60 hrs) (* 60 min) sec)))
 200
 201 ;;;###autoload
 202 (defun midnight-delay-set (symb tm)
 203   "Modify `midnight-timer' according to `midnight-delay'.
 204 Sets the first argument SYMB (which must be symbol `midnight-delay')
 205 to its second argument TM."
 206   (cl-assert (eq symb 'midnight-delay) t
 207              "Invalid argument to `midnight-delay-set': `%s'")
 208   (set symb tm)
 209   (when (timerp midnight-timer) (cancel-timer midnight-timer))
 210   (setq midnight-timer
 211         (run-at-time (if (numberp tm) (+ (midnight-next) tm) tm)
 212                      midnight-period 'run-hooks 'midnight-hook)))
 213
 214 (defcustom midnight-delay 3600
 215   "The number of seconds after the midnight when the `midnight-timer' is run.
 216 You should set this variable before loading midnight.el, or
 217 set it by calling `midnight-delay-set', or use `custom'.
 218 If you wish, you can use a string instead, it will be passed as the
 219 first argument to `run-at-time'."
 220   :type 'sexp
 221   :set 'midnight-delay-set
 222   :group 'midnight)
 223
 224 (provide 'midnight)
 225
 226 ;;; midnight.el ends here