;;; autorevert.el --- revert buffers when files on disk change
-;; Copyright (C) 1997-1999, 2001-2012 Free Software Foundation, Inc.
+;; Copyright (C) 1997-1999, 2001-2013 Free Software Foundation, Inc.
;; Author: Anders Lindgren <andersl@andersl.com>
;; Keywords: convenience
;; Emacs. You should never even notice that this package is active
;; (except that your buffers will be reverted, of course).
;;
+;; If Emacs is compiled with file watch support, notifications are
+;; used instead of checking the time stamp of the files.
+;;
;; After reverting a file buffer, Auto Revert Mode normally puts point
;; at the same position that a regular manual revert would. However,
;; there is one exception to this rule. If point is at the end of the
(set (make-local-variable 'auto-revert-tail-pos)
(nth 7 (file-attributes buffer-file-name)))))
+(defconst auto-revert-notify-enabled
+ (or (featurep 'inotify) (featurep 'w32notify))
+ "Non-nil when Emacs has been compiled with file watch support.")
+
+(when auto-revert-notify-enabled
+ (add-hook 'kill-buffer-hook 'auto-revert-notify-rm-watch))
+
+(defvar auto-revert-notify-watch-descriptor-hash-list
+ (make-hash-table :test 'equal)
+ "A hash table collecting all file watch descriptors.
+Hash key is a watch descriptor, hash value is the corresponding buffer.")
+
+(defvar auto-revert-notify-watch-descriptor nil
+ "The file watch descriptor active for the current buffer.")
+(make-variable-buffer-local 'auto-revert-notify-watch-descriptor)
+
+(defvar auto-revert-notify-modified-p nil
+ "Non-nil when file has been modified on the file system.
+This has been reported by a file watch event.")
+(make-variable-buffer-local 'auto-revert-notify-modified-p)
+
;; Functions:
;;;###autoload
(if auto-revert-mode
(if (not (memq (current-buffer) auto-revert-buffer-list))
(push (current-buffer) auto-revert-buffer-list))
+ (when auto-revert-notify-enabled (auto-revert-notify-rm-watch))
(setq auto-revert-buffer-list
(delq (current-buffer) auto-revert-buffer-list)))
(auto-revert-set-timer)
specifies in the mode line."
:global t :group 'auto-revert :lighter global-auto-revert-mode-text
(auto-revert-set-timer)
- (when global-auto-revert-mode
- (auto-revert-buffers)))
-
+ (if global-auto-revert-mode
+ (auto-revert-buffers)
+ (when auto-revert-notify-enabled
+ (dolist (buf (buffer-list))
+ (with-current-buffer buf
+ (auto-revert-notify-rm-watch))))))
(defun auto-revert-set-timer ()
"Restart or cancel the timer used by Auto-Revert Mode.
auto-revert-interval
'auto-revert-buffers))))
+(defun auto-revert-notify-rm-watch ()
+ "Disable file watch for current buffer's associated file."
+ (when auto-revert-notify-watch-descriptor
+ (funcall (if (fboundp 'inotify-rm-watch) 'inotify-rm-watch 'w32-rm-watch)
+ auto-revert-notify-watch-descriptor)
+ (remhash auto-revert-notify-watch-descriptor
+ auto-revert-notify-watch-descriptor-hash-list))
+ (setq auto-revert-notify-watch-descriptor nil
+ auto-revert-notify-modified-p nil))
+
+(defun auto-revert-notify-add-watch ()
+ "Enable file watch for current buffer's associated file."
+ (when (and buffer-file-name auto-revert-notify-enabled)
+ (auto-revert-notify-rm-watch)
+ (let ((func (if (fboundp 'inotify-add-watch)
+ 'inotify-add-watch 'w32-add-watch))
+ (aspect (if (fboundp 'inotify-add-watch)
+ '(close-write) '(last-write-time))))
+ (setq auto-revert-notify-watch-descriptor
+ (funcall func buffer-file-name aspect 'auto-revert-notify-handler))
+ (puthash auto-revert-notify-watch-descriptor
+ (current-buffer)
+ auto-revert-notify-watch-descriptor-hash-list))))
+
+(defun auto-revert-notify-handler (event)
+ "Handle an event returned from file watch."
+ (when (listp event)
+ (let ((buffer
+ (gethash (car event) auto-revert-notify-watch-descriptor-hash-list)))
+ (when (bufferp buffer)
+ (with-current-buffer buffer
+ (setq auto-revert-notify-modified-p t))))))
+
(defun auto-revert-active-p ()
"Check if auto-revert is active (in current buffer or globally)."
(or auto-revert-mode
(setq size
(nth 7 (file-attributes
buffer-file-name))))))
- (and (not (file-remote-p buffer-file-name))
- (file-readable-p buffer-file-name)
- (not (verify-visited-file-modtime buffer)))))
+ (if auto-revert-notify-enabled
+ ;; There are file watches.
+ auto-revert-notify-modified-p
+ (and (not (file-remote-p buffer-file-name))
+ (file-readable-p buffer-file-name)
+ (not (verify-visited-file-modtime buffer))))))
(and (or auto-revert-mode
global-auto-revert-non-file-buffers)
revert-buffer-function
(funcall buffer-stale-function t))))
eob eoblist)
(when revert
+ (setq auto-revert-notify-modified-p nil)
(when (and auto-revert-verbose
(not (eq revert 'fast)))
(message "Reverting buffer `%s'." (buffer-name)))
(memq buf auto-revert-buffer-list))
(setq auto-revert-buffer-list
(delq buf auto-revert-buffer-list)))
- (when (auto-revert-active-p) (auto-revert-handler)))
+ (when (auto-revert-active-p)
+ ;; Enable file watches.
+ (when (and auto-revert-notify-enabled buffer-file-name
+ (not auto-revert-notify-watch-descriptor)
+ (auto-revert-notify-add-watch)))
+ (auto-revert-handler)))
;; Remove dead buffer from `auto-revert-buffer-list'.
(setq auto-revert-buffer-list
(delq buf auto-revert-buffer-list))))