;;; 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
;; Auto-Revert Mode applies to all file buffers. (If the user option
;; `global-auto-revert-non-file-buffers' is non-nil, it also applies
;; to some non-file buffers. This option is disabled by default.)
-;; Since checking a remote file is too slow, these modes do not check
-;; or revert remote files.
+;;
+;; Since checking a remote file is slow, these modes check or revert
+;; remote files only if the user option `auto-revert-remote-files' is
+;; non-nil. It is recommended to disable version control for remote
+;; files.
;;
;; Both modes operate by checking the time stamp of all files at
;; intervals of `auto-revert-interval'. The default is every five
;; 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 notification 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. Alternatively, a regular expression of directories to be
+;; excluded from file notifications can be specified by
+;; `auto-revert-notify-exclude-dir-regexp'.
+;;
;; 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
;; change by growing at the end. It only appends the new output,
;; instead of reverting the entire buffer. It does so even if the
;; buffer contains unsaved changes. (Because they will not be lost.)
-;; Auto Revert Tail Mode works also for remote files.
;; Usage:
;;
;; 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)
This variable becomes buffer local when set in any fashion.")
(make-variable-buffer-local 'global-auto-revert-ignore-buffer)
+(defcustom auto-revert-remote-files nil
+ "If non-nil remote files are also reverted."
+ :group 'auto-revert
+ :type 'boolean
+ :version "24.4")
+
+(defconst auto-revert-notify-enabled
+ (or (featurep 'inotify) (featurep 'w32notify))
+ "Non-nil when Emacs has been compiled with file notification support.")
+
+(defcustom auto-revert-use-notify auto-revert-notify-enabled
+ "If non-nil Auto Revert Mode uses file notification functions.
+This requires Emacs being compiled with file notification
+support (see `auto-revert-notify-enabled'). You should set this
+variable through Custom."
+ :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)))))))
+ :initialize 'custom-initialize-default
+ :version "24.4")
+
+(defcustom auto-revert-notify-exclude-dir-regexp
+ (concat
+ ;; No mounted file systems.
+ "^" (regexp-opt '("/afs/" "/media/" "/mnt" "/net/" "/tmp_mnt/"))
+ ;; No remote files.
+ (unless auto-revert-remote-files "\\|^/[^/|:][^/|]+:"))
+ "Regular expression of directories to be excluded from file notifications."
+ :group 'auto-revert
+ :type 'regexp
+ :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 a list of buffers
+which are related to files being watched and carrying the same
+default directory.")
+
+(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)
+(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 notification 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)
+ (dolist (buf (buffer-list))
+ (with-current-buffer buf
+ (when auto-revert-use-notify
+ (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 notification for current buffer's associated file."
+ (when auto-revert-notify-watch-descriptor
+ (maphash
+ (lambda (key value)
+ (when (equal key auto-revert-notify-watch-descriptor)
+ (setq value (delete (current-buffer) value))
+ (if value
+ (puthash key value auto-revert-notify-watch-descriptor-hash-list)
+ (remhash key auto-revert-notify-watch-descriptor-hash-list)
+ (ignore-errors
+ (funcall (if (fboundp 'inotify-rm-watch)
+ 'inotify-rm-watch 'w32notify-rm-watch)
+ 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 notification for current buffer's associated file."
+ (when (string-match auto-revert-notify-exclude-dir-regexp
+ (expand-file-name default-directory))
+ ;; Fallback to file checks.
+ (set (make-local-variable 'auto-revert-use-notify) nil))
+
+ (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)
+ '(create modify moved-to) '(size last-write-time))))
+ (setq auto-revert-notify-watch-descriptor
+ (ignore-errors
+ (funcall
+ func (directory-file-name (expand-file-name default-directory))
+ aspect 'auto-revert-notify-handler)))
+ (if auto-revert-notify-watch-descriptor
+ (progn
+ (puthash
+ auto-revert-notify-watch-descriptor
+ (cons (current-buffer)
+ (gethash auto-revert-notify-watch-descriptor
+ auto-revert-notify-watch-descriptor-hash-list))
+ 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 notification 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 file notification event, or nil."
+ (and (auto-revert-notify-event-p event) (car event)))
+
+(defun auto-revert-notify-event-action (event)
+ "Return action of file 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 file 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 notification."
+ (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))
+ (buffers (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 (or (memq 'create action)
+ (memq 'modify action)
+ (memq 'moved-to action))))
+ (when (featurep 'w32notify) (cl-assert (eq 'modified action)))
+ ;; Since we watch a directory, a file name must be returned.
+ (cl-assert (stringp file))
+ (dolist (buffer buffers)
+ (when (buffer-live-p buffer)
+ (with-current-buffer buffer
+ (when (and (stringp buffer-file-name)
+ (string-equal
+ (file-name-nondirectory file)
+ (file-name-nondirectory buffer-file-name)))
+ ;; Mark buffer modified.
+ (setq auto-revert-notify-modified-p t)
+ ;; No need to check other buffers.
+ (cl-return)))))))))
+
(defun auto-revert-active-p ()
"Check if auto-revert is active (in current buffer or globally)."
(or auto-revert-mode
This is an internal function used by Auto-Revert Mode."
(when (or auto-revert-tail-mode (not (buffer-modified-p)))
(let* ((buffer (current-buffer)) size
+ ;; Tramp caches the file attributes. Setting
+ ;; `remote-file-name-inhibit-cache' forces Tramp to reread
+ ;; the values.
+ (remote-file-name-inhibit-cache t)
(revert
(or (and buffer-file-name
- (file-readable-p buffer-file-name)
+ (or auto-revert-remote-files
+ (not (file-remote-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
- ;; `remote-file-name-inhibit-cache' forces Tramp
- ;; to reread the values.
- (let ((remote-file-name-inhibit-cache t))
- (/= auto-revert-tail-pos
- (setq size
- (nth 7 (file-attributes
- buffer-file-name)))))
- (and (not (file-remote-p buffer-file-name))
+ (and (file-readable-p buffer-file-name)
+ (/= auto-revert-tail-pos
+ (setq size
+ (nth 7 (file-attributes
+ buffer-file-name)))))
+ (and (file-readable-p buffer-file-name)
(not (verify-visited-file-modtime buffer)))))
(and (or auto-revert-mode
global-auto-revert-non-file-buffers)
(functionp buffer-stale-function)
(funcall buffer-stale-function t))))
eob eoblist)
+ (setq auto-revert-notify-modified-p nil)
(when revert
(when (and auto-revert-verbose
(not (eq revert 'fast)))
(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 notification.
+ (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))))