X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/cf20dee0248049a925275f54381cf63bb2017e35..68a08a32e3979396d53fc5da371d928b9c7df881:/lisp/autorevert.el diff --git a/lisp/autorevert.el b/lisp/autorevert.el index 11005f49f4..1ee1db0165 100644 --- a/lisp/autorevert.el +++ b/lisp/autorevert.el @@ -1,6 +1,6 @@ ;;; 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 ;; Keywords: convenience @@ -48,6 +48,11 @@ ;; 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 @@ -92,11 +97,9 @@ ;; 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 @@ -257,6 +260,27 @@ buffers. CPU usage depends on the version control system." 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 () @@ -279,6 +303,20 @@ the list of old buffers.") (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 @@ -299,6 +337,7 @@ 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) @@ -402,9 +441,12 @@ It displays the text that `global-auto-revert-mode-text' 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. @@ -421,6 +463,87 @@ will use an up-to-date value of `auto-revert-interval'" 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 @@ -438,6 +561,8 @@ This is an internal function used by Auto-Revert Mode." (let* ((buffer (current-buffer)) size (revert (or (and 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 @@ -459,6 +584,7 @@ This is an internal function used by Auto-Revert Mode." (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))) @@ -564,7 +690,12 @@ the timer when no buffers need to be checked." (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))))