Initial revision

lisp/midnight.el

+;;; midnight.el --- run something every midnight, e.g., kill old buffers.
+
+;;; Copyright (C) 1998 Free Software Foundation, Inc.
+
+;;; Author: Sam Steingold <sds@usa.net>
+;;; Maintainer: Sam Steingold <sds@usa.net>
+;;; Created: 1998-05-18
+;;; Keywords: utilities
+
+;; 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 2, 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; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+
+;; To use the file, put (require 'midnight) into your .emacs.  Then, at
+;; midnight, Emacs will run the normal hook `midnight-hook'.  You can
+;; put whatever you like there, say, `calendar'; by default there is
+;; only one function there - `clean-buffer-list'. It will kill the
+;; buffers matching `clean-buffer-list-kill-buffer-names' and
+;; `clean-buffer-list-kill-regexps' and the buffers which where last
+;; displayed more than `clean-buffer-list-delay-general' days ago,
+;; keeping `clean-buffer-list-kill-never-buffer-names' and
+;; `clean-buffer-list-kill-never-regexps'.
+
+(eval-when-compile (require 'cl))
+
+(defgroup midnight nil
+  "Run something every day at midnight."
+  :group 'calendar)
+
+;;; time conversion
+
+(defun float-time (&optional tm)
+  "Convert `current-time' to a float number of seconds."
+  (multiple-value-bind (s0 s1 s2) (or tm (current-time))
+    (+ (* (float (ash 1 16)) s0) (float s1) (* 0.0000001 s2))))
+
+(defun time-float (num)
+  "Convert the float number of seconds since epoch to the list of 3 integers."
+  (let* ((div (ash 1 16)) (1st (floor num div)))
+    (list 1st (floor (- num (* (float div) 1st)))
+          (round (* 10000000 (mod num 1))))))
+
+(defun buffer-display-time (&optional buf)
+  "Return the time-stamp of the given buffer, or current buffer, as float."
+  (save-excursion
+    (set-buffer (or buf (current-buffer)))
+    (when buffer-display-time (float-time buffer-display-time))))
+
+;;; clean-buffer-list stuff
+
+(defcustom clean-buffer-list-delay-general 3
+  "*The number of days before any buffer becomes eligible for autokilling.
+The autokilling is done by `clean-buffer-list' when is it in `midnight-hook'.
+Currently displayed and/or modified (unsaved) buffers, as well as buffers
+matching `clean-buffer-list-kill-never-buffer-names' and
+`clean-buffer-list-kill-never-regexps' are excluded."
+  :type 'integer
+  :group 'midnight
+  :version "20.3")
+
+(defcustom clean-buffer-list-delay-special 3600
+  "*The number of seconds before some buffers become eligible for autokilling.
+Buffers matched by `clean-buffer-list-kill-regexps' and
+`clean-buffer-list-kill-buffer-names' are killed if they were last
+displayed more than this many seconds ago."
+  :type 'integer
+  :group 'midnight
+  :version "20.3")
+
+(defcustom clean-buffer-list-kill-regexps nil
+  "*List of regexps saying which buffers will be killed at midnight.
+If buffer name matches a regexp in the list and the buffer was not displayed
+in the last `clean-buffer-list-delay-special' seconds, it is killed by
+`clean-buffer-list' when is it in `midnight-hook'.
+If a member of the list is a cons, it's `car' is the regexp and its `cdr' is
+the number of seconds to use instead of `clean-buffer-list-delay-special'.
+See also `clean-buffer-list-kill-buffer-names',
+`clean-buffer-list-kill-never-regexps' and
+`clean-buffer-list-kill-never-buffer-names'."
+  :type 'list
+  :group 'midnight
+  :version "20.3")
+
+(defcustom clean-buffer-list-kill-buffer-names
+    '("*Help*" "*Apropos*" "*Man " "*Buffer List*" "*Compile-Log*" "*info*")
+  "*List of strings saying which buffers will be killed at midnight.
+Buffers with names in this list, which were not displayed in the last
+`clean-buffer-list-delay-special' seconds, are killed by `clean-buffer-list'
+when is it in `midnight-hook'.
+If a member of the list is a cons, it's `car' is the name and its `cdr' is
+the number of seconds to use instead of `clean-buffer-list-delay-special'.
+See also `clean-buffer-list-kill-regexps',
+`clean-buffer-list-kill-never-regexps' and
+`clean-buffer-list-kill-never-buffer-names'."
+  :type 'list
+  :group 'midnight
+  :version "20.3")
+
+(defcustom clean-buffer-list-kill-never-buffer-names
+    '("*scratch*" "*Messages*")
+  "*List of buffer names which will never be killed by `clean-buffer-list'.
+See also `clean-buffer-list-kill-never-regexps'.
+Note that this does override `clean-buffer-list-kill-regexps' and
+`clean-buffer-list-kill-buffer-names' so a buffer matching any of these
+two lists will NOT be killed if it is also present in this list."
+  :type 'list
+  :group 'midnight
+  :version "20.3")
+
+(defcustom clean-buffer-list-kill-never-regexps '("^ \*Minibuf-.*\*$")
+  "*List of regexp saying which buffers will never be killed at midnight.
+See also `clean-buffer-list-kill-never-buffer-names'.
+Killing is done by `clean-buffer-list'.
+Note that this does override `clean-buffer-list-kill-regexps' and
+`clean-buffer-list-kill-buffer-names' so a buffer matching any of these
+two lists will NOT be killed if it also matches anything in this list."
+  :type 'list
+  :group 'midnight
+  :version "20.3")
+
+(defun midnight-find (el ls test &optional key)
+  "A stopgap solution to the absence of `find' in ELisp."
+  (if (fboundp 'find)
+      (find el ls :test test :key (or key 'eql))
+      (loop for rr in ls when (funcall test el (if key (funcall key rr) rr))
+            return rr)))
+
+(defun clean-buffer-list-delay (bn)
+  "Return the delay, in seconds, before this buffer name is auto-killed.
+Uses `clean-buffer-list-kill-buffer-names', `clean-buffer-list-kill-regexps'
+`clean-buffer-list-delay-general' and `clean-buffer-list-delay-special'.
+Autokilling is done by `clean-buffer-list'."
+  (flet ((ff (ls ts)
+           (let ((zz (midnight-find
+                      bn ls ts (lambda (xx) (if (consp xx) (car xx) xx)))))
+             (cond ((consp zz) (cdr zz))
+                   ((null zz) nil)
+                   (clean-buffer-list-delay-special)))))
+    (or (ff clean-buffer-list-kill-buffer-names 'string=)
+        (ff clean-buffer-list-kill-regexps 'string-match)
+        (* clean-buffer-list-delay-general 24 60 60))))
+
+(defun clean-buffer-list ()
+  "Kill old buffers.
+The relevant vartiables are `clean-buffer-list-delay-general',
+`clean-buffer-list-delay-special', `clean-buffer-list-kill-buffer-names',
+`clean-buffer-list-kill-never-buffer-names',
+`clean-buffer-list-kill-regexps' and `clean-buffer-list-kill-never-regexps'."
+  (interactive)
+  (let ((tm (float-time)) bts (ts (format-time-string "%Y-%m-%d %T")) bn)
+    (dolist (buf (buffer-list))
+      (message "[%s] processing `%s'..." ts buf)
+      (setq bts (buffer-display-time buf) bn (buffer-name buf))
+      (unless (or ;; (string-match clean-buffer-list-kill-never bn)
+                  (midnight-find bn clean-buffer-list-kill-never-regexps
+                                 'string-match)
+                  (midnight-find bn clean-buffer-list-kill-never-buffer-names
+                                 'string-equal)
+                  (buffer-modified-p buf) (get-buffer-window buf 'visible)
+                  (null bts) (< (- tm bts) (clean-buffer-list-delay bn)))
+        (message "[%s] killing `%s'" ts bn)
+        (kill-buffer buf)))))
+
+;;; midnight hook
+
+(defvar midnight-period (* 24 60 60)
+  "The number of seconds in a day - the delta for `midnight-timer'.")
+
+(defcustom midnight-hook 'clean-buffer-list
+  "The hook run `midnight-delay' seconds after midnight every day.
+The default value is `clean-buffer-list'."
+  :type 'hook
+  :group 'midnight
+  :version "20.3")
+
+(defun midnight-next ()
+  "Return the number of seconds till the next midnight."
+  (multiple-value-bind (sec min hrs) (decode-time)
+    (- (* 24 60 60) (* 60 60 hrs) (* 60 min) sec)))
+
+(defvar midnight-timer nil
+  "Timer running the `midnight-hook' `midnight-delay' seconds after midnight.
+Use `cancel-timer' to stop it and `midnight-delay-set' to change
+the time when it is run.")
+
+;;;###autoload
+(defun midnight-delay-set (symb tm)
+  "Modify `midnight-timer' according to `midnight-delay'.
+Sets the first argument (which must be symbol `midnight-delay')
+to its second argument."
+  (unless (eq symb 'midnight-delay)
+    (error "Illegal argument to `midnight-delay-set': `%s'" symb))
+  (set symb tm)
+  (when (timerp midnight-timer) (cancel-timer midnight-timer))
+  (setq midnight-timer
+        (run-at-time (if (numberp tm) (+ (midnight-next) tm) tm)
+                     midnight-period 'run-hooks 'midnight-hook)))
+
+(defcustom midnight-delay 3600
+  "*The number of seconds after the midnight when the `midnight-timer' is run.
+You should set this variable before loading midnight.el, or
+set it by calling `midnight-delay-set', or use `custom'.
+If you wish, you can use a string instead, it will be passed as the
+first argument to `run-at-time'."
+  :type 'sexp
+  :set 'midnight-delay-set
+  :group 'midnight
+  :version "20.3")
+
+(provide 'midnight)
+
+;;; midnight.el ends here