lisp/riece-shrink-buffer.el

   1 ;;; riece-shrink-buffer.el --- free old IRC messages to save memory usage
   2 ;; Copyright (C) 1998-2005 Daiki Ueno
   3
   4 ;; Author: Daiki Ueno <ueno@unixuser.org>
   5 ;; Created: 1998-09-28
   6 ;; Keywords: IRC, riece
   7
   8 ;; This file is part of Riece.
   9
  10 ;; This program is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; This program is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23 ;; Boston, MA 02110-1301, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; NOTE: This is an add-on module for Riece.
  28
  29 ;;; Code:
  30
  31 (require 'riece-globals)
  32 (require 'derived)
  33
  34 (defgroup riece-shrink-buffer nil
  35   "Free old IRC messages to save memory usage."
  36   :prefix "riece-"
  37   :group 'riece)
  38
  39 (defcustom riece-shrink-buffer-idle-time-delay 5
  40   "Number of idle seconds to wait before shrinking channel buffers."
  41   :type 'integer
  42   :group 'riece-shrink-buffer)
  43
  44 (defcustom riece-max-buffer-size 65536
  45   "Maximum size of channel buffers."
  46   :type '(integer :tag "Number of characters")
  47   :group 'riece-shrink-buffer)
  48
  49 (defcustom riece-shrink-buffer-remove-chars (/ riece-max-buffer-size 2)
  50   "Number of chars removed when shrinking channel buffers."
  51   :type 'integer
  52   :group 'riece-shrink-buffer)
  53
  54 (defvar riece-shrink-buffer-idle-timer nil
  55   "Timer object to periodically shrink channel buffers.")
  56
  57 (defconst riece-shrink-buffer-description
  58   "Free old IRC messages to save memory usage.")
  59
  60 (defun riece-shrink-buffer-idle-timer ()
  61   (let ((buffers riece-buffer-list))
  62     (while buffers
  63       (if (and (get 'riece-shrink-buffer 'riece-addon-enabled)
  64                (buffer-live-p (car buffers))
  65                (with-current-buffer (car buffers)
  66                  (riece-derived-mode-p 'riece-dialogue-mode)))
  67           (riece-shrink-buffer (car buffers)))
  68       (setq buffers (cdr buffers)))))
  69
  70 (defun riece-shrink-buffer (buffer)
  71   (save-excursion
  72     (set-buffer buffer)
  73     (goto-char (point-min))
  74     (while (> (buffer-size) riece-max-buffer-size)
  75       (let* ((inhibit-read-only t)
  76              buffer-read-only
  77              (end (progn
  78                     (goto-char riece-shrink-buffer-remove-chars)
  79                     (beginning-of-line 2)
  80                     (point)))
  81              (overlays (riece-overlays-in (point-min) end)))
  82         (while overlays
  83           (riece-delete-overlay (car overlays))
  84           (setq overlays (cdr overlays)))
  85         (delete-region (point-min) end)))))
  86
  87 (defun riece-shrink-buffer-startup-hook ()
  88   (setq riece-shrink-buffer-idle-timer
  89         (riece-run-with-idle-timer
  90          riece-shrink-buffer-idle-time-delay t
  91          'riece-shrink-buffer-idle-timer)))
  92
  93 (defun riece-shrink-buffer-exit-hook ()
  94   (if riece-shrink-buffer-idle-timer
  95       (riece-cancel-timer riece-shrink-buffer-idle-timer)))
  96
  97 (defun riece-shrink-buffer-insinuate ()
  98   (add-hook 'riece-startup-hook
  99             'riece-shrink-buffer-startup-hook)
 100   ;; Reset the timer since riece-shrink-buffer-insinuate will be
 101   ;; called before running riece-startup-hook.
 102   (unless riece-shrink-buffer-idle-timer
 103     (riece-shrink-buffer-startup-hook))
 104   (add-hook 'riece-exit-hook
 105             'riece-shrink-buffer-exit-hook))
 106
 107 (defun riece-shrink-buffer-uninstall ()
 108   (riece-shrink-buffer-exit-hook)
 109   (remove-hook 'riece-startup-hook
 110                'riece-shrink-buffer-startup-hook)
 111   (remove-hook 'riece-exit-hook
 112                'riece-shrink-buffer-exit-hook))
 113
 114 (provide 'riece-shrink-buffer)
 115
 116 ;;; riece-shrink-buffer.el ends here