emacs/lisp/erc/erc-truncate.el

184 lines
7.9 KiB
EmacsLisp

;;; erc-truncate.el --- Functions for truncating ERC buffers -*- lexical-binding: t; -*-
;; Copyright (C) 2003-2004, 2006-2024 Free Software Foundation, Inc.
;; Author: Andreas Fuchs <asf@void.at>
;; Maintainer: Amin Bandali <bandali@gnu.org>, F. Jason Park <jp@neverwas.me>
;; URL: https://www.emacswiki.org/emacs/ErcTruncation
;; Keywords: IRC, chat, client, Internet, logging
;; 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 3 of the License, 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. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; This file implements buffer truncation through the `truncate'
;; module, with optional `log' module integration.
;;; Code:
(require 'erc)
(defgroup erc-truncate nil
"Truncate buffers when they reach a certain size."
:group 'erc)
(defcustom erc-max-buffer-size 30000
"Buffer size in characters after truncation.
Only applies when the `truncate' module is enabled."
:type 'integer)
(defcustom erc-truncate-padding-size 4096
"Headroom threshold triggering truncation and determining its frequency.
Truncation occurs when the buffer's size meets or exceeds this value
plus `erc-max-buffer-size'."
:type 'integer
:package-version '(ERC . "5.6.1"))
;;;###autoload(autoload 'erc-truncate-mode "erc-truncate" nil t)
(define-erc-module truncate nil
"Truncate a query buffer if it gets too large.
This prevents the query buffer from getting too large, which can
bring any grown Emacs to its knees after a few days worth of
tracking heavy-traffic channels.
Before ERC 5.6, this module performed logging whenever the \\+`log'
module's library, \\+`erc-log', happened to be loaded, regardless of
whether the \\+`log' module itself was enabled. (Loading can of course
happen in any number of ways, such as when browsing options via
\\[customize-group] or completing autoloaded symbol names at the
\\[describe-variable] prompt.) Users of \\+`truncate' who prefer the
old behavior can add \\+`log' to `erc-modules' to get the same effect.
Those who don't want logging but need to load the \\+`erc-log' library
for other purposes should customize either `erc-enable-logging' or
`erc-log-channels-directory' to avoid the annoying warning."
;;enable
((add-hook 'erc-insert-done-hook #'erc-truncate-buffer)
(add-hook 'erc-connect-pre-hook #'erc-truncate--warn-about-logging)
(add-hook 'erc-mode-hook #'erc-truncate--setup)
(unless erc--updating-modules-p (erc-buffer-do #'erc-truncate--setup)))
;; disable
((remove-hook 'erc-insert-done-hook #'erc-truncate-buffer)
(remove-hook 'erc-connect-pre-hook #'erc-truncate--warn-about-logging)
(remove-hook 'erc-mode-hook #'erc-truncate--setup)
(erc-buffer-do #'erc-truncate--setup)))
(defvar-local erc-truncate--buffer-size nil
"Temporary buffer-local override for `erc-max-buffer-size'.")
(defun erc-truncate--setup ()
"Enable or disable buffer-local `erc-truncate-mode' modifications."
(if erc-truncate-mode
(progn
(when-let* ((priors (or erc--server-reconnecting erc--target-priors))
(val (alist-get 'erc-truncate--buffer-size priors)))
(setq erc-truncate--buffer-size val))
(add-function :before (local 'erc--clear-function)
#'erc-truncate--inhibit-when-local-and-interactive
'((depth . 20))))
(remove-function (local 'erc--clear-function)
#'erc-truncate--inhibit-when-local-and-interactive)
(kill-local-variable 'erc-truncate--buffer-size)))
(defun erc-truncate--warn-about-logging (&rest _)
(when (and (not erc--target)
(fboundp 'erc-log--check-legacy-implicit-enabling-by-truncate)
(erc-log--check-legacy-implicit-enabling-by-truncate))
;; Emit a real Emacs warning because the message may be
;; truncated away before it can be read if merely inserted.
(erc-button--display-error-notice-with-keys-and-warn
"The `truncate' module no longer enables logging implicitly."
" See the doc string for `erc-truncate-mode' for details.")))
;;;###autoload
(defun erc-truncate-buffer-to-size (size &optional buffer)
"Truncate BUFFER or the current buffer to SIZE.
Log the deleted region when the `log' module is active and
`erc-logging-enabled' returns non-nil.
Note that prior to ERC 5.6, whenever erc-log.el happened to be
loaded and the option `erc-enable-logging' was left at its
default value, this function would cause logging to commence
regardless of whether `erc-log-mode' was enabled or `log' was
present in `erc-modules'."
;; If buffer is non-nil, but get-buffer does not return anything,
;; then this is a bug. If buffer is a buffer name, get the buffer
;; object. If buffer is nil, use the current buffer.
(if (not buffer)
(setq buffer (current-buffer))
(unless (get-buffer buffer)
(error "erc-truncate-buffer-to-size: %S is not a buffer" buffer)))
(when (and (> (buffer-size buffer) (+ size erc-truncate-padding-size))
(not (buffer-local-value 'erc--inhibit-clear-p buffer)))
(with-current-buffer buffer
(let ((wc (and (get-buffer-window) (current-window-configuration))))
(save-excursion
;; Widen to preserve pre-5.5 behavior.
(save-restriction
(widen)
(let ((beg (point-min-marker))
(end (goto-char (- erc-insert-marker size))))
;; Truncate at message boundary (formerly line boundary
;; before 5.6).
(goto-char (or (erc--get-inserted-msg-beg end) (pos-bol)))
(setq end (point-marker))
(with-silent-modifications
(let ((erc--inhibit-clear-p t))
(funcall erc--clear-function beg end)))
(set-marker beg nil)
(set-marker end nil))))
(when wc
(set-window-configuration wc))))))
;;;###autoload
(defun erc-truncate-buffer ()
"Truncate current buffer to `erc-max-buffer-size'."
(interactive)
;; This `save-excursion' only exists for historical reasons because
;; `erc-truncate-buffer-to-size' normally runs in a different buffer.
(save-excursion
(if (and erc--parsed-response erc--msg-props)
(when-let*
(((not erc--inhibit-clear-p))
((not (erc--memq-msg-prop 'erc--skip 'truncate)))
;; Determine here because this may be a target buffer and
;; the hook always runs in the server buffer.
(size (if (and erc-truncate--buffer-size
(> erc-truncate--buffer-size erc-max-buffer-size))
erc-truncate--buffer-size
erc-max-buffer-size))
(symbol (make-symbol "erc-truncate--buffer-deferred"))
(buffer (current-buffer)))
(fset symbol
(lambda (&rest _)
(remove-hook 'erc-timer-hook symbol t)
(erc-truncate-buffer-to-size size buffer)))
(erc-with-server-buffer (add-hook 'erc-timer-hook symbol -80 t)))
(unless erc--inhibit-clear-p
(erc-truncate-buffer-to-size erc-max-buffer-size)))))
(defun erc-truncate--inhibit-when-local-and-interactive (&rest _)
"Ensure `erc-truncate--buffer-size' is nil on /CLEAR."
(when (and erc--called-as-input-p erc-truncate--buffer-size)
(message "Resetting max buffer size to %d" erc-max-buffer-size)
(setq erc-truncate--buffer-size nil)))
(provide 'erc-truncate)
;;; erc-truncate.el ends here
;;
;; Local Variables:
;; generated-autoload-file: "erc-loaddefs.el"
;; End: