* autorevert.el (auto-revert-remote-files)

(auto-revert-notify-exclude-dir-regexp): New defcustoms.
(auto-revert-notify-enabled, auto-revert-use-notify)
(auto-revert-notify-watch-descriptor-hash-list)
(auto-revert-notify-modified-p, auto-revert-notify-event-p)
(auto-revert-notify-event-descriptor)
(auto-revert-notify-event-action)
(auto-revert-notify-event-file-name): Doc fix.
(global-auto-revert-mode): Reorder checks.
(auto-revert-notify-rm-watch): Respect changed values of
`auto-revert-notify-watch-descriptor-hash-list'.
(auto-revert-notify-add-watch): Check for
`auto-revert-notify-exclude-dir-regexp'.  Adapt filters for
`inotify-add-watch'.  Watch `default-directory' instead of
`buffer-file-name'.  `auto-revert-notify-watch-descriptor-hash-list'
has a changed meaning now.  (Bug#13540)
(auto-revert-notify-handler): Change implementation wrt events
returning from a directory.
(auto-revert-handler): Reorder implementation for checks of remote
files.
(auto-revert-buffers): Fix parentheses error.

2 files changed, 138 insertions, 64 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 1fc7b5d49ce..7c600ca7e6f 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,27 @@
+2013-01-25  Michael Albinus  <michael.albinus@gmx.de>
+
+        * autorevert.el (auto-revert-remote-files)
+        (auto-revert-notify-exclude-dir-regexp): New defcustoms.
+        (auto-revert-notify-enabled, auto-revert-use-notify)
+        (auto-revert-notify-watch-descriptor-hash-list)
+        (auto-revert-notify-modified-p, auto-revert-notify-event-p)
+        (auto-revert-notify-event-descriptor)
+        (auto-revert-notify-event-action)
+        (auto-revert-notify-event-file-name): Doc fix.
+        (global-auto-revert-mode): Reorder checks.
+        (auto-revert-notify-rm-watch): Respect changed values of
+        `auto-revert-notify-watch-descriptor-hash-list'.
+        (auto-revert-notify-add-watch): Check for
+        `auto-revert-notify-exclude-dir-regexp'.  Adapt filters for
+        `inotify-add-watch'.  Watch `default-directory' instead of
+        `buffer-file-name'.  `auto-revert-notify-watch-descriptor-hash-list'
+        has a changed meaning now.  (Bug#13540)
+        (auto-revert-notify-handler): Change implementation wrt events
+        returning from a directory.
+        (auto-revert-handler): Reorder implementation for checks of remote
+        files.
+        (auto-revert-buffers): Fix parentheses error.
+
 2013-01-25  Fabián Ezequiel Gallina  <fgallina@cuca>
 
         * progmodes/python.el: Enhancements to header documentation about
diff --git a/lisp/autorevert.el b/lisp/autorevert.el
index 1b5460ff2cf..25a953e1719 100644
--- a/lisp/autorevert.el
+++ b/lisp/autorevert.el
@@ -39,8 +39,11 @@
 ;; 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
@@ -48,10 +51,12 @@
 ;; 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
+;; 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.
+;; 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,
@@ -70,7 +75,6 @@
 ;; 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:
 ;;
@@ -260,15 +264,21 @@ 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)
 
+(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 watch support.")
+  "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 watch functions.
-This requires Emacs being compiled with file watch support (see
-`auto-revert-notify-enabled').  You should set this variable
-through Custom only."
+  "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 only."
   :group 'auto-revert
   :type 'boolean
   :set (lambda (variable value)
@@ -281,6 +291,17 @@ through Custom only."
                    (auto-revert-notify-rm-watch)))))))
   :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 ()
@@ -306,7 +327,9 @@ the list of old buffers.")
 (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.")
+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.")
@@ -315,7 +338,7 @@ Hash key is a watch descriptor, hash value is the corresponding buffer.")
 
 (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.")
+This has been reported by a file notification event.")
 (make-variable-buffer-local 'auto-revert-notify-modified-p)
 
 ;; Functions:
@@ -444,9 +467,9 @@ specifies in the mode line."
   (auto-revert-set-timer)
   (if global-auto-revert-mode
       (auto-revert-buffers)
-    (when auto-revert-use-notify
-      (dolist (buf (buffer-list))
-        (with-current-buffer buf
+    (dolist (buf (buffer-list))
+      (with-current-buffer buf
+        (when auto-revert-use-notify
           (auto-revert-notify-rm-watch))))))
 
 (defun auto-revert-set-timer ()
@@ -465,85 +488,106 @@ will use an up-to-date value of `auto-revert-interval'"
                             'auto-revert-buffers))))
 
 (defun auto-revert-notify-rm-watch ()
-  "Disable file watch for current buffer's associated file."
+  "Disable file notification 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)
+    (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 watch for current buffer's associated file."
+  "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)
-                      '(modify) '(size last-write-time))))
+                      '(create modify moved-to) '(size last-write-time))))
       (setq auto-revert-notify-watch-descriptor
             (ignore-errors
               (funcall
-               func buffer-file-name aspect 'auto-revert-notify-handler)))
+               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
-                     (current-buffer)
-                     auto-revert-notify-watch-descriptor-hash-list)
+            (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 watch 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 notification event, or nil."
+  "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 notification event, or nil."
+  "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 notification event, or nil."
+  "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 watch."
+  "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))
-           (buffer (gethash descriptor
-                            auto-revert-notify-watch-descriptor-hash-list)))
+           (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 (memq 'modify action)))
+        (when (featurep 'inotify)
+          (cl-assert (or (memq 'create action)
+                         (memq 'modify action)
+                         (memq 'moved-to 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))))))
+        ;; 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)."
@@ -560,23 +604,29 @@ will use an up-to-date value of `auto-revert-interval'"
 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
-                     (or (not auto-revert-use-notify)
-                         auto-revert-notify-modified-p)
+                     (or auto-revert-remote-files
+                         (not (file-remote-p buffer-file-name)))
                      (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))
-                           (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 (not auto-revert-use-notify)
+                                  auto-revert-notify-modified-p)
+                              (file-readable-p buffer-file-name)
+                              (/= auto-revert-tail-pos
+                                  (setq size
+                                        (nth 7 (file-attributes
+                                                buffer-file-name)))))
+                       ;; When `auto-revert-use-notify' is set, we do
+                       ;; not apply further checks for performance
+                       ;; reasons.
+                       (if auto-revert-use-notify
+                           auto-revert-notify-modified-p
+                         (and (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
@@ -692,10 +742,10 @@ the timer when no buffers need to be checked."
                     (setq auto-revert-buffer-list
                           (delq buf auto-revert-buffer-list)))
                 (when (auto-revert-active-p)
-                  ;; Enable file watches.
+                  ;; Enable file notification.
                   (when (and auto-revert-use-notify buffer-file-name
-                             (not auto-revert-notify-watch-descriptor)
-                      (auto-revert-notify-add-watch)))
+                             (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