;;; autorevert.el --- revert buffers when files on disk change
-;; Copyright (C) 1997-1999, 2001-2011 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. You can
+;; disable this by setting the user option `auto-revert-use-notify' to
+;; nil.
+;;
;; 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
;; M-x global-auto-revert-mode RET
;;
;; To activate Global Auto-Revert Mode every time Emacs is started
-;; customise the option `global-auto-revert-mode' or the following
+;; customize the option `global-auto-revert-mode' or the following
;; line could be added to your ~/.emacs:
;; (global-auto-revert-mode 1)
;;
;; Dependencies:
+(eval-when-compile (require 'cl-lib))
(require 'timer)
-(eval-when-compile (require 'cl))
-
-
;; Custom Group:
;;
;; The two modes will be placed next to Auto Save Mode under the
(defgroup auto-revert nil
"Revert individual buffers when files on disk change.
-
-Auto-Revert Mode can be activated for individual buffer.
-Global Auto-Revert Mode applies to all buffers."
+Auto-Revert mode enables auto-revert in individual buffers.
+Global Auto-Revert mode does so in all buffers."
:group 'files
:group 'convenience)
;;; What's this?: ;; Autoload for the benefit of `make-mode-line-mouse-sensitive'.
;;; What's this?: ;;;###autoload
(defvar auto-revert-mode nil
- "*Non-nil when Auto-Revert Mode is active.
+ "Non-nil when Auto-Revert Mode is active.
Never set this variable directly, use the command `auto-revert-mode' instead.")
(put 'auto-revert-mode 'permanent-local t)
(defvar auto-revert-tail-mode nil
- "*Non-nil when Auto-Revert Tail Mode is active.
+ "Non-nil when Auto-Revert Tail Mode is active.
Never set this variable directly, use the command
`auto-revert-tail-mode' instead.")
(put 'auto-revert-tail-mode 'permanent-local t)
:version "22.1")
(defvar global-auto-revert-ignore-buffer nil
- "*When non-nil, Global Auto-Revert Mode will not revert this buffer.
-
+ "When non-nil, Global Auto-Revert Mode will not revert this buffer.
This variable becomes buffer local when set in any fashion.")
(make-variable-buffer-local 'global-auto-revert-ignore-buffer)
+(defconst auto-revert-notify-enabled
+ (or (featurep 'inotify) (featurep 'w32notify))
+ "Non-nil when Emacs has been compiled with file watch support.")
+
+(defcustom auto-revert-use-notify auto-revert-notify-enabled
+ "If non-nil Auto Revert Mode uses file watch functions.
+This requires Emacs being compiled with file watch support (see
+`auto-revert-notify-enabled'). You should set this variable
+through Custom only."
+ :group 'auto-revert
+ :type 'boolean
+ :set (lambda (variable value)
+ (set-default variable (and auto-revert-notify-enabled value))
+ (unless (symbol-value variable)
+ (when auto-revert-notify-enabled
+ (dolist (buf (buffer-list))
+ (with-current-buffer buf
+ (when (symbol-value 'auto-revert-notify-watch-descriptor)
+ (auto-revert-notify-rm-watch)))))))
+ :version "24.4")
+
;; Internal variables:
(defvar auto-revert-buffer-list ()
(set (make-local-variable 'auto-revert-tail-pos)
(nth 7 (file-attributes buffer-file-name)))))
+(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.")
+(put 'auto-revert-notify-watch-descriptor 'permanent-local t)
+
+(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
(define-minor-mode auto-revert-mode
- "Toggle reverting buffer when file on disk changes.
+ "Toggle reverting buffer when the file changes (Auto Revert mode).
+With a prefix argument ARG, enable Auto Revert mode if ARG is
+positive, and disable it otherwise. If called from Lisp, enable
+the mode if ARG is omitted or nil.
+
+Auto Revert mode is a minor mode that affects only the current
+buffer. When enabled, it reverts the buffer when the file on
+disk changes.
-With arg, turn Auto Revert mode on if and only if arg is positive.
-This is a minor mode that affects only the current buffer.
Use `global-auto-revert-mode' to automatically revert all buffers.
Use `auto-revert-tail-mode' if you know that the file will only grow
without being changed in the part that is already in the buffer."
(if auto-revert-mode
(if (not (memq (current-buffer) auto-revert-buffer-list))
(push (current-buffer) auto-revert-buffer-list))
+ (when auto-revert-use-notify (auto-revert-notify-rm-watch))
(setq auto-revert-buffer-list
(delq (current-buffer) auto-revert-buffer-list)))
(auto-revert-set-timer)
;;;###autoload
(define-minor-mode auto-revert-tail-mode
- "Toggle reverting tail of buffer when file on disk grows.
-With arg, turn Tail mode on if arg is positive, otherwise turn it off.
+ "Toggle reverting tail of buffer when the file grows.
+With a prefix argument ARG, enable Auto-Revert Tail mode if ARG
+is positive, and disable it otherwise. If called from Lisp,
+enable the mode if ARG is omitted or nil.
-When Tail mode is enabled, the tail of the file is constantly
-followed, as with the shell command `tail -f'. This means that
-whenever the file grows on disk (presumably because some
-background process is appending to it from time to time), this is
-reflected in the current buffer.
+When Auto Revert Tail mode is enabled, the tail of the file is
+constantly followed, as with the shell command `tail -f'. This
+means that whenever the file grows on disk (presumably because
+some background process is appending to it from time to time),
+this is reflected in the current buffer.
You can edit the buffer and turn this mode off and on again as
you please. But make sure the background process has stopped
;;;###autoload
(defun turn-on-auto-revert-tail-mode ()
- "Turn on Auto-Revert Tail Mode.
+ "Turn on Auto-Revert Tail mode.
This function is designed to be added to hooks, for example:
(add-hook 'my-logfile-mode-hook 'turn-on-auto-revert-tail-mode)"
;;;###autoload
(define-minor-mode global-auto-revert-mode
"Toggle Global Auto Revert mode.
-With optional prefix argument ARG, enable Global Auto Revert Mode
-if ARG > 0, else disable it.
+With a prefix argument ARG, enable Global Auto Revert mode if ARG
+is positive, and disable it otherwise. If called from Lisp,
+enable the mode if ARG is omitted or nil.
-This is a global minor mode that reverts any buffer associated
-with a file when the file changes on disk. Use `auto-revert-mode'
-to revert a particular buffer.
+Global Auto Revert mode is a global minor mode that reverts any
+buffer associated with a file when the file changes on disk. Use
+`auto-revert-mode' to revert a particular buffer.
If `global-auto-revert-non-file-buffers' is non-nil, this mode
may also revert some non-file buffers, as described in the
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-use-notify
+ (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
+ (ignore-errors
+ (funcall (if (fboundp 'inotify-rm-watch)
+ 'inotify-rm-watch 'w32notify-rm-watch)
+ auto-revert-notify-watch-descriptor))
+ (remhash auto-revert-notify-watch-descriptor
+ auto-revert-notify-watch-descriptor-hash-list)
+ (remove-hook 'kill-buffer-hook 'auto-revert-notify-rm-watch))
+ (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-use-notify
+ (not auto-revert-notify-watch-descriptor))
+ (let ((func (if (fboundp 'inotify-add-watch)
+ 'inotify-add-watch 'w32notify-add-watch))
+ (aspect (if (fboundp 'inotify-add-watch)
+ '(modify) '(size last-write-time))))
+ (setq auto-revert-notify-watch-descriptor
+ (ignore-errors
+ (funcall
+ func buffer-file-name aspect 'auto-revert-notify-handler)))
+ (if auto-revert-notify-watch-descriptor
+ (progn
+ (puthash auto-revert-notify-watch-descriptor
+ (current-buffer)
+ auto-revert-notify-watch-descriptor-hash-list)
+ (add-hook (make-local-variable 'kill-buffer-hook)
+ 'auto-revert-notify-rm-watch))
+ ;; Fallback to file checks.
+ (set (make-local-variable 'auto-revert-use-notify) nil)))))
+
+(defun auto-revert-notify-event-p (event)
+ "Check that event is a file watch event."
+ (cond ((featurep 'inotify)
+ (and (listp event) (= (length event) 4)))
+ ((featurep 'w32notify)
+ (and (listp event) (= (length event) 3) (stringp (nth 2 event))))))
+
+(defun auto-revert-notify-event-descriptor (event)
+ "Return watch descriptor of notification event, or nil."
+ (and (auto-revert-notify-event-p event) (car event)))
+
+(defun auto-revert-notify-event-action (event)
+ "Return action of notification event, or nil."
+ (and (auto-revert-notify-event-p event) (nth 1 event)))
+
+(defun auto-revert-notify-event-file-name (event)
+ "Return file name of notification event, or nil."
+ (and (auto-revert-notify-event-p event)
+ (cond ((featurep 'inotify) (nth 3 event))
+ ((featurep 'w32notify) (nth 2 event)))))
+
+(defun auto-revert-notify-handler (event)
+ "Handle an event returned from file watch."
+ (when (auto-revert-notify-event-p event)
+ (let* ((descriptor (auto-revert-notify-event-descriptor event))
+ (action (auto-revert-notify-event-action event))
+ (file (auto-revert-notify-event-file-name event))
+ (buffer (gethash descriptor
+ auto-revert-notify-watch-descriptor-hash-list)))
+ (ignore-errors
+ ;; Check, that event is meant for us.
+ ;; TODO: Filter events which stop watching, like `move' or `removed'.
+ (cl-assert descriptor)
+ (when (featurep 'inotify) (cl-assert (memq 'modify action)))
+ (when (featurep 'w32notify) (cl-assert (eq 'modified action)))
+ (cl-assert (bufferp buffer))
+ (with-current-buffer buffer
+ (when (and (stringp file) (stringp buffer-file-name))
+ ;; w32notify returns the basename of the file without its
+ ;; leading directories; inotify returns its full absolute
+ ;; file name.
+ (cl-assert (file-equal-p file buffer-file-name)))
+
+ ;; Mark buffer modified.
+ (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
(let* ((buffer (current-buffer)) size
(revert
(or (and buffer-file-name
- (file-readable-p buffer-file-name)
+ (or (not auto-revert-use-notify)
+ auto-revert-notify-modified-p)
(if auto-revert-tail-mode
;; Tramp caches the file attributes. Setting
- ;; `tramp-cache-inhibit' forces Tramp to
- ;; reread the values.
- (let ((tramp-cache-inhibit-cache t))
- (/= auto-revert-tail-pos
- (setq size
- (nth 7 (file-attributes
- buffer-file-name)))))
+ ;; `remote-file-name-inhibit-cache' forces Tramp
+ ;; to reread the values.
+ (let ((remote-file-name-inhibit-cache t))
+ (and (file-readable-p buffer-file-name)
+ (/= auto-revert-tail-pos
+ (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)))))
(and (or auto-revert-mode
global-auto-revert-non-file-buffers)
(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)))
(when buffer-file-name
(setq eob (eobp))
(walk-windows
- #'(lambda (window)
- (and (eq (window-buffer window) buffer)
- (= (window-point window) (point-max))
- (push window eoblist)))
+ (lambda (window)
+ (and (eq (window-buffer window) buffer)
+ (= (window-point window) (point-max))
+ (push window eoblist)))
'no-mini t))
(if auto-revert-tail-mode
(auto-revert-tail-handler size)
(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-use-notify 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))))