* files.el (remote-file-name-inhibit-cache): New defcustom.

* time.el (display-time-file-nonempty-p): Use
`remote-file-name-inhibit-cache'.

* net/tramp.el (tramp-completion-reread-directory-timeout): Fix
docstring.

* net/tramp-cache.el (tramp-cache-inhibit-cache): Remove.
(tramp-get-file-property): Replace `tramp-cache-inhibit-cache' by
`remote-file-name-inhibit-cache'.  Check also for an integer
value.  Add/increase counter when `tramp-verbose' >= 10.
(tramp-set-file-property): Add/increase counter when
`tramp-verbose' >= 10.

* net/tramp-cmds.el (tramp-cleanup-all-connections)
(tramp-cleanup-all-buffers): Set tramp-autoload cookie.
(tramp-bug): Set tramp-autoload cookie.  Report all interned
tramp-* variables.  Report also `remote-file-name-inhibit-cache'.
(tramp-reporter-dump-variable): Fix docstring.  Mask non-7bit
characters only in strings.

* net/tramp-compat.el (remote-file-name-inhibit-cache): Define due
to backward compatibility.

* net/tramp-sh.el (tramp-handle-verify-visited-file-modtime)
(tramp-handle-file-name-all-completions)
(tramp-handle-vc-registered): Use
`remote-file-name-inhibit-cache'.
(tramp-open-connection-setup-interactive-shell): Call
`tramp-cleanup-connection' directly.

9 files changed, 146 insertions, 123 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 91374cab45c..044db17a44c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,37 @@
+2010-10-02  Michael Albinus  <michael.albinus@gmx.de>
+
+        * files.el (remote-file-name-inhibit-cache): New defcustom.
+
+        * time.el (display-time-file-nonempty-p): Use
+        `remote-file-name-inhibit-cache'.
+
+        * net/tramp.el (tramp-completion-reread-directory-timeout): Fix
+        docstring.
+
+        * net/tramp-cache.el (tramp-cache-inhibit-cache): Remove.
+        (tramp-get-file-property): Replace `tramp-cache-inhibit-cache' by
+        `remote-file-name-inhibit-cache'.  Check also for an integer
+        value.  Add/increase counter when `tramp-verbose' >= 10.
+        (tramp-set-file-property): Add/increase counter when
+        `tramp-verbose' >= 10.
+
+        * net/tramp-cmds.el (tramp-cleanup-all-connections)
+        (tramp-cleanup-all-buffers): Set tramp-autoload cookie.
+        (tramp-bug): Set tramp-autoload cookie.  Report all interned
+        tramp-* variables.  Report also `remote-file-name-inhibit-cache'.
+        (tramp-reporter-dump-variable): Fix docstring.  Mask non-7bit
+        characters only in strings.
+
+        * net/tramp-compat.el (remote-file-name-inhibit-cache): Define due
+        to backward compatibility.
+
+        * net/tramp-sh.el (tramp-handle-verify-visited-file-modtime)
+        (tramp-handle-file-name-all-completions)
+        (tramp-handle-vc-registered): Use
+        `remote-file-name-inhibit-cache'.
+        (tramp-open-connection-setup-interactive-shell): Call
+        `tramp-cleanup-connection' directly.
+
 2010-10-02  Glenn Morris  <rgm@gnu.org>
 
         * emacs-lisp/checkdoc.el (checkdoc-minor-keymap): Remove obsolete alias.
diff --git a/lisp/files.el b/lisp/files.el
index 92574283dd7..bb49f44fda5 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -949,6 +949,36 @@ to that remote system.
         (funcall handler 'file-remote-p file identification connected)
       nil)))
 
+(defcustom remote-file-name-inhibit-cache 10
+  "Whether to use the remote file-name cache for read access.
+
+When `nil', always use the cached values.
+When `t', never use them.
+A number means use them for that amount of seconds since they were
+cached.
+
+File attributes of remote files are cached for better performance.
+If they are changed out of Emacs' control, the cached values
+become invalid, and must be invalidated.
+
+In case a remote file is checked regularly, it might be
+reasonable to let-bind this variable to a value less then the
+time period between two checks.
+Example:
+
+  \(defun display-time-file-nonempty-p \(file)
+    \(let \(\(remote-file-name-inhibit-cache \(- display-time-interval 5)))
+      \(and \(file-exists-p file)
+           \(< 0 \(nth 7 \(file-attributes \(file-chase-links file)))))))"
+  :group 'files
+  :version "24.1"
+  :type `(choice
+          (const   :tag "Do not inhibit file name cache" nil)
+          (const   :tag "Do not use file name cache" t)
+          (integer :tag "Do not use file name cache"
+                   :format "Do not use file name cache older then %v seconds"
+                   :value 10)))
+
 (defun file-local-copy (file)
   "Copy the file FILE into a temporary file on this machine.
 Returns the name of the local copy, or nil, if FILE is directly
diff --git a/lisp/net/tramp-cache.el b/lisp/net/tramp-cache.el
index 5745546e3e8..7885d143cc2 100644
--- a/lisp/net/tramp-cache.el
+++ b/lisp/net/tramp-cache.el
@@ -59,13 +59,6 @@
 (defvar tramp-cache-data (make-hash-table :test 'equal)
   "Hash table for remote files properties.")
 
-(defvar tramp-cache-inhibit-cache nil
-  "Inhibit cache read access, when `t'.
-`nil' means to accept cache entries unconditionally.  If the
-value is a timestamp (as returned by `current-time'), cache
-entries are not used when they have been written before this
-time.")
-
 (defcustom tramp-persistency-file-name
   (cond
    ;; GNU Emacs.
@@ -104,19 +97,25 @@ Returns DEFAULT if not set."
          (value (when (hash-table-p hash) (gethash property hash))))
     (if
         ;; We take the value only if there is any, and
-        ;; `tramp-cache-inhibit-cache' indicates that it is still
+        ;; `remote-file-name-inhibit-cache' indicates that it is still
         ;; valid.  Otherwise, DEFAULT is set.
         (and (consp value)
-             (or (null tramp-cache-inhibit-cache)
-                 (and (consp tramp-cache-inhibit-cache)
+             (or (null remote-file-name-inhibit-cache)
+                 (and (integerp remote-file-name-inhibit-cache)
+                      (<=
+                       (tramp-time-diff (current-time) (car value))
+                       remote-file-name-inhibit-cache))
+                 (and (consp remote-file-name-inhibit-cache)
                       (tramp-time-less-p
-                       tramp-cache-inhibit-cache (car value)))))
+                       remote-file-name-inhibit-cache (car value)))))
         (setq value (cdr value))
       (setq value default))
 
-    (if (consp tramp-cache-inhibit-cache)
-        (tramp-message vec 1 "%s %s %s" file property value))
     (tramp-message vec 8 "%s %s %s" file property value)
+    (when (>= tramp-verbose 10)
+      (let* ((var (intern (concat "tramp-cache-get-count-" property)))
+             (val (or (ignore-errors (symbol-value var)) 0)))
+        (set var (1+ val))))
     value))
 
 ;;;###tramp-autoload
@@ -132,6 +131,10 @@ Returns VALUE."
     ;; We put the timestamp there.
     (puthash property (cons (current-time) value) hash)
     (tramp-message vec 8 "%s %s %s" file property value)
+    (when (>= tramp-verbose 10)
+      (let* ((var (intern (concat "tramp-cache-set-count-" property)))
+             (val (or (ignore-errors (symbol-value var)) 0)))
+        (set var (1+ val))))
     value))
 
 ;;;###tramp-autoload
diff --git a/lisp/net/tramp-cmds.el b/lisp/net/tramp-cmds.el
index 5937a737b96..e6e1bc671e7 100644
--- a/lisp/net/tramp-cmds.el
+++ b/lisp/net/tramp-cmds.el
@@ -99,6 +99,7 @@ When called interactively, a Tramp connection has to be selected."
                    (tramp-get-connection-property vec "process-buffer" nil)))
       (when (bufferp buf) (kill-buffer buf)))))
 
+;;;###tramp-autoload
 (defun tramp-cleanup-all-connections ()
   "Flush all Tramp internal objects.
 This includes password cache, file cache, connection cache, buffers."
@@ -117,6 +118,7 @@ This includes password cache, file cache, connection cache, buffers."
   (dolist (name (tramp-list-tramp-buffers))
     (when (bufferp (get-buffer name)) (kill-buffer name))))
 
+;;;###tramp-autoload
 (defun tramp-cleanup-all-buffers ()
   "Kill all remote buffers."
   (interactive)
@@ -141,6 +143,7 @@ This includes password cache, file cache, connection cache, buffers."
 
 (autoload 'reporter-submit-bug-report "reporter")
 
+;;;###tramp-autoload
 (defun tramp-bug ()
   "Submit a bug report to the Tramp developers."
   (interactive)
@@ -150,65 +153,25 @@ This includes password cache, file cache, connection cache, buffers."
       (reporter-submit-bug-report
        tramp-bug-report-address         ; to-address
        (format "tramp (%s)" tramp-version) ; package name and version
-       (delq nil
-             `(;; Current state
-               tramp-current-method
-               tramp-current-user
-               tramp-current-host
-
-               ;; System defaults
-               tramp-auto-save-directory        ; vars to dump
-               tramp-default-method
-               tramp-default-method-alist
-               tramp-default-host
-               tramp-default-proxies-alist
-               tramp-default-user
-               tramp-default-user-alist
-               tramp-rsh-end-of-line
-               tramp-default-password-end-of-line
-               tramp-login-prompt-regexp
-               ;; Mask non-7bit characters
-               (tramp-password-prompt-regexp . tramp-reporter-dump-variable)
-               tramp-wrong-passwd-regexp
-               tramp-yesno-prompt-regexp
-               tramp-yn-prompt-regexp
-               tramp-terminal-prompt-regexp
-               tramp-temp-name-prefix
-               tramp-file-name-structure
-               tramp-file-name-regexp
-               tramp-methods
-               tramp-end-of-output
-               tramp-local-coding-commands
-               tramp-remote-coding-commands
-               tramp-actions-before-shell
-               tramp-actions-copy-out-of-band
-               tramp-terminal-type
-               ;; Mask non-7bit characters
-               (tramp-shell-prompt-pattern . tramp-reporter-dump-variable)
-               ,(when (boundp 'tramp-backup-directory-alist)
-                  'tramp-backup-directory-alist)
-               ,(when (boundp 'tramp-bkup-backup-directory-info)
-                  'tramp-bkup-backup-directory-info)
-               ;; Dump cache.
-               (tramp-cache-data . tramp-reporter-dump-variable)
-
-               ;; Non-tramp variables of interest
-               ;; Mask non-7bit characters
-               (shell-prompt-pattern . tramp-reporter-dump-variable)
-               backup-by-copying
-               backup-by-copying-when-linked
-               backup-by-copying-when-mismatch
-               ,(when (boundp 'backup-by-copying-when-privileged-mismatch)
-                  'backup-by-copying-when-privileged-mismatch)
-               ,(when (boundp 'password-cache)
-                  'password-cache)
-               ,(when (boundp 'password-cache-expiry)
-                  'password-cache-expiry)
-               ,(when (boundp 'backup-directory-alist)
-                  'backup-directory-alist)
-               ,(when (boundp 'bkup-backup-directory-info)
-                  'bkup-backup-directory-info)
-               file-name-handler-alist))
+       (sort
+        (delq nil (mapcar
+          (lambda (x)
+            (and x (boundp x) (cons x 'tramp-reporter-dump-variable)))
+          (append
+           (mapcar 'intern (all-completions "tramp-" obarray 'boundp))
+           ;; Non-tramp variables of interest.
+           '(shell-prompt-pattern
+             backup-by-copying
+             backup-by-copying-when-linked
+             backup-by-copying-when-mismatch
+             backup-by-copying-when-privileged-mismatch
+             backup-directory-alist
+             bkup-backup-directory-info
+             password-cache
+             password-cache-expiry
+             remote-file-name-inhibit-cache
+             file-name-handler-alist))))
+        (lambda (x y) (string< (symbol-name (car x)) (symbol-name (car y)))))
 
        'tramp-load-report-modules       ; pre-hook
        'tramp-append-tramp-buffers      ; post-hook
@@ -238,8 +201,7 @@ buffer in your bug report.
 "))))
 
 (defun tramp-reporter-dump-variable (varsym mailbuf)
-  "Pretty-print the value of the variable in symbol VARSYM.
-Used for non-7bit chars in strings."
+  "Pretty-print the value of the variable in symbol VARSYM."
   (let* ((reporter-eval-buffer (symbol-value 'reporter-eval-buffer))
          (val (with-current-buffer reporter-eval-buffer
                 (symbol-value varsym))))
@@ -247,12 +209,13 @@ Used for non-7bit chars in strings."
     (if (hash-table-p val)
         ;; Pretty print the cache.
         (set varsym (read (format "(%s)" (tramp-cache-print val))))
-      ;; There are characters to be masked.
+      ;; There are non-7bit characters to be masked.
       (when (and (boundp 'mm-7bit-chars)
+                 (stringp val)
                  (string-match
                   (concat "[^" (symbol-value 'mm-7bit-chars) "]") val))
         (with-current-buffer reporter-eval-buffer
-          (set varsym (format "(base64-decode-string \"%s\""
+          (set varsym (format "(base64-decode-string \"%s\")"
                               (base64-encode-string val))))))
 
     ;; Dump variable.
@@ -268,7 +231,7 @@ Used for non-7bit chars in strings."
                      "\\(\")\\)" "\"$"))                    ;; \4 "
         (replace-match "\\1\\2\\3\\4")
         (beginning-of-line)
-        (insert " ;; variable encoded due to non-printable characters\n"))
+        (insert " ;; Variable encoded due to non-printable characters.\n"))
       (forward-line 1))
 
     ;; Reset VARSYM to old value.
@@ -277,7 +240,6 @@ Used for non-7bit chars in strings."
 
 (defun tramp-load-report-modules ()
   "Load needed modules for reporting."
-
   ;; We load message.el and mml.el from Gnus.
   (if (featurep 'xemacs)
       (progn
@@ -290,7 +252,6 @@ Used for non-7bit chars in strings."
 
 (defun tramp-append-tramp-buffers ()
   "Append Tramp buffers and buffer local variables into the bug report."
-
   (goto-char (point-max))
 
   ;; Dump buffer local variables.
diff --git a/lisp/net/tramp-compat.el b/lisp/net/tramp-compat.el
index 5156711fa47..afbaa8064dc 100644
--- a/lisp/net/tramp-compat.el
+++ b/lisp/net/tramp-compat.el
@@ -96,6 +96,11 @@
     (defvar byte-compile-not-obsolete-vars nil))
   (setq byte-compile-not-obsolete-vars '(directory-sep-char))
 
+  ;; `remote-file-name-inhibit-cache' has been introduced with Emacs 24.1.
+  ;; Besides `t', `nil', and integer, we use also timestamps (as
+  ;; returned by `current-time') internally.
+  (defvar remote-file-name-inhibit-cache nil)
+
   ;; For not existing functions, or functions with a changed argument
   ;; list, there are compiler warnings.  We want to avoid them in
   ;; cases we know what we do.
diff --git a/lisp/net/tramp-gvfs.el b/lisp/net/tramp-gvfs.el
index cd2bab26f47..151e03e88ab 100644
--- a/lisp/net/tramp-gvfs.el
+++ b/lisp/net/tramp-gvfs.el
@@ -531,7 +531,6 @@ is no information where to trace the message.")
 (defun tramp-gvfs-dbus-event-error (event err)
   "Called when a D-Bus error message arrives, see `dbus-event-error-hooks'."
   (when tramp-gvfs-dbus-event-vector
-    ;(tramp-cleanup-connection tramp-gvfs-dbus-event-vector)
     (tramp-message tramp-gvfs-dbus-event-vector 10 "%S" event)
     (tramp-error tramp-gvfs-dbus-event-vector 'file-error "%s" (cadr err))))
 
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index 423b4fcbd5e..e31e2e23745 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -1366,8 +1366,8 @@ of."
               (not (tramp-file-name-handler 'file-remote-p f nil 'connected)))
           t
         (with-parsed-tramp-file-name f nil
-          (tramp-flush-file-property v localname)
-          (let* ((attr (file-attributes f))
+          (let* ((remote-file-name-inhibit-cache t)
+                 (attr (file-attributes f))
                  (modtime (nth 5 attr))
                  (mt (visited-file-modtime)))
 
@@ -1770,46 +1770,39 @@ and gid of the corresponding user is taken.  Both parameters must be integers."
        (mapcar
         'list
         (or
-         ;; Try cache first
-         (and
-          ;; Ignore if expired
-          (or (not (integerp tramp-completion-reread-directory-timeout))
-              (<= (tramp-time-diff
-                   (current-time)
-                   (tramp-get-file-property
-                    v localname "last-completion" '(0 0 0)))
-                  tramp-completion-reread-directory-timeout))
-
-          ;; Try cache entries for filename, filename with last
-          ;; character removed, filename with last two characters
-          ;; removed, ..., and finally the empty string - all
-          ;; concatenated to the local directory name
-
-          ;; This is inefficient for very long filenames, pity
-          ;; `reduce' is not available...
-          (car
-           (apply
-            'append
-            (mapcar
-             (lambda (x)
-               (let ((cache-hit
-                      (tramp-get-file-property
-                       v
-                       (concat localname (substring filename 0 x))
-                       "file-name-all-completions"
-                       nil)))
-                 (when cache-hit (list cache-hit))))
-             (tramp-compat-number-sequence (length filename) 0 -1)))))
+         ;; Try cache entries for filename, filename with last
+         ;; character removed, filename with last two characters
+         ;; removed, ..., and finally the empty string - all
+         ;; concatenated to the local directory name.
+         (let ((remote-file-name-inhibit-cache
+                (or remote-file-name-inhibit-cache
+                    tramp-completion-reread-directory-timeout)))
+
+           ;; This is inefficient for very long filenames, pity
+           ;; `reduce' is not available...
+           (car
+            (apply
+             'append
+             (mapcar
+              (lambda (x)
+                (let ((cache-hit
+                       (tramp-get-file-property
+                        v
+                        (concat localname (substring filename 0 x))
+                        "file-name-all-completions"
+                        nil)))
+                  (when cache-hit (list cache-hit))))
+              (tramp-compat-number-sequence (length filename) 0 -1)))))
 
          ;; Cache expired or no matching cache entry found so we need
-         ;; to perform a remote operation
+         ;; to perform a remote operation.
          (let (result)
            ;; Get a list of directories and files, including reliably
            ;; tagging the directories with a trailing '/'.  Because I
            ;; rock.  --daniel@danann.net
 
            ;; Changed to perform `cd' in the same remote op and only
-           ;; get entries starting with `filename'. Capture any `cd'
+           ;; get entries starting with `filename'.  Capture any `cd'
            ;; error messages.  Ensure any `cd' and `echo' aliases are
            ;; ignored.
            (tramp-send-command
@@ -1904,9 +1897,6 @@ tramp-handle-file-name-all-completions: internal error accessing `%s': `%s'"
                     v (concat localname entry) "file-exists-p" t))
                  result)
 
-           (tramp-set-file-property
-            v localname "last-completion" (current-time))
-
            ;; Store result in the cache
            (tramp-set-file-property
             v (concat localname filename)
@@ -3669,7 +3659,7 @@ Returns a file name in `tramp-auto-save-directory' for autosaving this file."
         ;; There could be new files, created by the vc backend.  We
         ;; cannot reuse the old cache entries, therefore.
         (let (tramp-vc-registered-file-names
-              (tramp-cache-inhibit-cache (current-time))
+              (remote-file-name-inhibit-cache (current-time))
               (file-name-handler-alist
                `((,tramp-file-name-regexp . tramp-vc-file-name-handler))))
 
@@ -4085,7 +4075,7 @@ process to set up.  VEC specifies the connection."
         ;; Keep the debug buffer.
         (rename-buffer
          (generate-new-buffer-name tramp-temp-buffer-name) 'unique)
-        (tramp-compat-funcall 'tramp-cleanup-connection vec)
+        (tramp-cleanup-connection vec)
         (if (= (point-min) (point-max))
             (kill-buffer nil)
           (rename-buffer (tramp-debug-buffer-name vec) 'unique))
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 3a3b3ad35e0..fa61aa02d70 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -974,8 +974,8 @@ A remote directory might have changed its contents.  In order to
 make it visible during file name completion in the minibuffer,
 Tramp flushes its cache and rereads the directory contents when
 more than `tramp-completion-reread-directory-timeout' seconds
-have been gone since last remote command execution.  A value of 0
-would require an immediate reread during filename completion, nil
+have been gone since last remote command execution.  A value of `t'
+would require an immediate reread during filename completion, `nil'
 means to use always cached values for the directory contents."
   :group 'tramp
   :type '(choice (const nil) integer))
diff --git a/lisp/time.el b/lisp/time.el
index d512faefee0..006fd758a7c 100644
--- a/lisp/time.el
+++ b/lisp/time.el
@@ -454,8 +454,9 @@ update which can wait for the next redisplay."
   (force-mode-line-update))
 
 (defun display-time-file-nonempty-p (file)
-  (and (file-exists-p file)
-       (< 0 (nth 7 (file-attributes (file-chase-links file))))))
+  (let ((remote-file-name-inhibit-cache (- display-time-interval 5)))
+    (and (file-exists-p file)
+         (< 0 (nth 7 (file-attributes (file-chase-links file)))))))
 
 ;;;###autoload
 (define-minor-mode display-time-mode