[Emacs-diffs] Changes to net/tramp-cache.el

[Michael Albinus]

CVSROOT:        /cvsroot/emacs
Module name:    emacs
Changes by:     Michael Albinus <albinus>       07/07/08 18:03:20

Index: net/tramp-cache.el
===================================================================
RCS file: net/tramp-cache.el
diff -N net/tramp-cache.el
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ net/tramp-cache.el  8 Jul 2007 18:03:19 -0000       1.1
@@ -0,0 +1,316 @@
+;;; -*- mode: Emacs-Lisp; coding: iso-2022-7bit; -*-
+;;; tramp-cache.el --- file information caching for Tramp
+
+;; Copyright (C) 2000, 2005, 2006, 2007 by Free Software Foundation, Inc.
+
+;; Author: Daniel Pittman <address@hidden>
+;;         Michael Albinus <address@hidden>
+;; Keywords: comm, processes
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, see
+;; <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; An implementation of information caching for remote files.
+
+;; Each connection, identified by a vector [method user host
+;; localname] or by a process, has a unique cache. We distinguish 3
+;; kind of caches, depending on the key:
+;;
+;; - localname is NIL.  This are reusable properties.  Examples:
+;;   "remote-shell" identifies the POSIX shell to be called on the
+;;   remote host, or "perl" is the command to be called on the remote
+;;   host, when starting a Perl script.  These properties are saved in
+;;   the file `tramp-persistency-file-name'.
+;;
+;; - localname is a string.  This are temporary properties, which are
+;;   related to the file localname is referring to.  Examples:
+;;   "file-exists-p" is t or nile, depending on the file existence, or
+;;   "file-attributes" caches the result of the function
+;;  `file-attributes'.
+;;
+;; - The key is a process.  This are temporary properties related to
+;;   an open connection.  Examples: "scripts" keeps shell script
+;;   definitions already sent to the remote shell, "last-cmd-time" is
+;;   the time stamp a command has been sent to the remote process.
+
+;;; Code:
+
+;; Pacify byte-compiler.
+(eval-when-compile
+  (require 'cl)
+  (autoload 'tramp-message "tramp")
+  (autoload 'tramp-tramp-file-p "tramp")
+  ;; We cannot autoload macro `with-parsed-tramp-file-name', it
+  ;; results in problems of byte-compiled code.
+  (autoload 'tramp-dissect-file-name "tramp")
+  (autoload 'tramp-file-name-method "tramp")
+  (autoload 'tramp-file-name-user "tramp")
+  (autoload 'tramp-file-name-host "tramp")
+  (autoload 'tramp-file-name-localname "tramp")
+  (autoload 'time-stamp-string "time-stamp"))
+
+;;; -- Cache --
+
+(defvar tramp-cache-data (make-hash-table :test 'equal)
+  "Hash table for remote files properties.")
+
+(defcustom tramp-persistency-file-name
+  (cond
+   ;; GNU Emacs.
+   ((and (boundp 'user-emacs-directory)
+        (stringp (symbol-value 'user-emacs-directory))
+        (file-directory-p (symbol-value 'user-emacs-directory)))
+    (expand-file-name "tramp" (symbol-value 'user-emacs-directory)))
+   ((and (not (featurep 'xemacs)) (file-directory-p "~/.emacs.d/"))
+    "~/.emacs.d/tramp")
+   ;; XEmacs.
+   ((and (boundp 'user-init-directory)
+        (stringp (symbol-value 'user-init-directory))
+        (file-directory-p (symbol-value 'user-init-directory)))
+    (expand-file-name "tramp" (symbol-value 'user-init-directory)))
+   ((and (featurep 'xemacs) (file-directory-p "~/.xemacs/"))
+    "~/.xemacs/tramp")
+   ;; For users without `~/.emacs.d/' or `~/.xemacs/'.
+   (t "~/.tramp"))
+  "File which keeps connection history for Tramp connections."
+  :group 'tramp
+  :type 'file)
+
+(defun tramp-get-file-property (vec file property default)
+  "Get the PROPERTY of FILE from the cache context of VEC.
+Returns DEFAULT if not set."
+  ;; Unify localname.
+  (setq vec (copy-sequence vec))
+  (aset vec 3 (directory-file-name file))
+  (let* ((hash (or (gethash vec tramp-cache-data)
+                  (puthash vec (make-hash-table :test 'equal)
+                           tramp-cache-data)))
+        (value (if (hash-table-p hash)
+                   (gethash property hash default)
+                 default)))
+    (tramp-message vec 8 "%s %s %s" file property value)
+    value))
+
+(defun tramp-set-file-property (vec file property value)
+  "Set the PROPERTY of FILE to VALUE, in the cache context of VEC.
+Returns VALUE."
+  ;; Unify localname.
+  (setq vec (copy-sequence vec))
+  (aset vec 3 (directory-file-name file))
+  (let ((hash (or (gethash vec tramp-cache-data)
+                 (puthash vec (make-hash-table :test 'equal)
+                          tramp-cache-data))))
+    (puthash property value hash)
+    (tramp-message vec 8 "%s %s %s" file property value)
+    value))
+
+(defun tramp-flush-file-property (vec file)
+  "Remove all properties of FILE in the cache context of VEC."
+  ;; Unify localname.
+  (setq vec (copy-sequence vec))
+  (aset vec 3 (directory-file-name file))
+  (tramp-message vec 8 "%s" file)
+  (remhash vec tramp-cache-data))
+
+(defun tramp-flush-directory-property (vec directory)
+  "Remove all properties of DIRECTORY in the cache context of VEC.
+Remove also properties of all files in subdirectories."
+  (let ((directory (directory-file-name directory)))
+  (tramp-message vec 8 "%s" directory)
+    (maphash
+     '(lambda (key value)
+       (when (and (stringp key)
+                  (string-match directory (tramp-file-name-localname key)))
+         (remhash key tramp-cache-data)))
+     tramp-cache-data)))
+
+(defun tramp-cache-print (table)
+  "Prints hash table TABLE."
+  (when (hash-table-p table)
+    (let (result tmp)
+      (maphash
+       '(lambda (key value)
+         (setq tmp (format
+                    "(%s %s)"
+                    (if (processp key)
+                        (prin1-to-string (prin1-to-string key))
+                      (prin1-to-string key))
+                    (if (hash-table-p value)
+                        (tramp-cache-print value)
+                      (if (bufferp value)
+                          (prin1-to-string (prin1-to-string value))
+                        (prin1-to-string value))))
+               result (if result (concat result " " tmp) tmp)))
+       table)
+      result)))
+
+;; Reverting or killing a buffer should also flush file properties.
+;; They could have been changed outside Tramp.
+(defun tramp-flush-file-function ()
+  "Flush all Tramp cache properties from buffer-file-name."
+  (let ((bfn (buffer-file-name)))
+    (when (and (stringp bfn) (tramp-tramp-file-p bfn))
+      (let* ((v (tramp-dissect-file-name bfn))
+            (localname (tramp-file-name-localname v)))
+       (tramp-flush-file-property v localname)))))
+
+(add-hook 'before-revert-hook 'tramp-flush-file-function)
+(add-hook 'kill-buffer-hook 'tramp-flush-file-function)
+(add-hook 'tramp-cache-unload-hook
+         '(lambda ()
+            (remove-hook 'before-revert-hook
+                         'tramp-flush-file-function)
+            (remove-hook 'kill-buffer-hook
+                         'tramp-flush-file-function)))
+
+;;; -- Properties --
+
+(defun tramp-get-connection-property (key property default)
+  "Get the named PROPERTY for the connection.
+KEY identifies the connection, it is either a process or a vector.
+If the value is not set for the connection, returns DEFAULT."
+  ;; Unify key by removing localname from vector.  Work with a copy in
+  ;; order to avoid side effects.
+  (when (vectorp key)
+    (setq key (copy-sequence key))
+    (aset key 3 nil))
+  (let* ((hash (gethash key tramp-cache-data))
+        (value (if (hash-table-p hash)
+                  (gethash property hash default)
+                default)))
+    (tramp-message key 7 "%s %s" property value)
+    value))
+
+(defun tramp-set-connection-property (key property value)
+  "Set the named PROPERTY of a connection to VALUE.
+KEY identifies the connection, it is either a process or a vector.
+PROPERTY is set persistent when KEY is a vector."
+  ;; Unify key by removing localname from vector.  Work with a copy in
+  ;; order to avoid side effects.
+  (when (vectorp key)
+    (setq key (copy-sequence key))
+    (aset key 3 nil))
+  (let ((hash (or (gethash key tramp-cache-data)
+                 (puthash key (make-hash-table :test 'equal)
+                           tramp-cache-data))))
+    (puthash property value hash)
+    ;; This function is called also during initialization of
+    ;; tramp-cache.el.  `tramp-message´ is not defined yet at this
+    ;; time, so we ignore the corresponding error.
+    (condition-case nil
+       (tramp-message key 7 "%s %s" property value)
+      (error nil))
+    value))
+
+(defun tramp-flush-connection-property (key event)
+  "Remove all properties identified by KEY.
+KEY identifies the connection, it is either a process or a
+vector.  EVENT is not used, it is just applied because this
+function is intended to run also as process sentinel."
+  ;; Unify key by removing localname from vector.  Work with a copy in
+  ;; order to avoid side effects.
+  (when (vectorp key)
+    (setq key (copy-sequence key))
+    (aset key 3 nil))
+;  (tramp-message key 7 "%s" event)
+  (remhash key tramp-cache-data))
+
+(defun tramp-dump-connection-properties ()
+"Writes persistent connection properties into file
+`tramp-persistency-file-name'."
+  ;; We shouldn't fail, otherwise (X)Emacs might not be able to be closed.
+  (condition-case nil
+      (when (and (hash-table-p tramp-cache-data)
+                (not (zerop (hash-table-count tramp-cache-data)))
+                (stringp tramp-persistency-file-name))
+       (let ((cache (copy-hash-table tramp-cache-data)))
+         ;; Remove temporary data.
+         (maphash
+          '(lambda (key value)
+             (if (and (vectorp key) (not (tramp-file-name-localname key)))
+                 (progn
+                   (remhash "process-name" value)
+                   (remhash "process-buffer" value))
+               (remhash key cache)))
+          cache)
+         ;; Dump it.
+         (with-temp-buffer
+           (insert
+            ";; -*- emacs-lisp -*-"
+            ;; `time-stamp-string' might not exist in all (X)Emacs flavors.
+            (condition-case nil
+                (progn
+                  (format
+                   " <%s %s>\n"
+                   (time-stamp-string "%02y/%02m/%02d %02H:%02M:%02S")
+                   tramp-persistency-file-name))
+              (error "\n"))
+            ";; Tramp connection history.  Don't change this file.\n"
+            ";; You can delete it, forcing Tramp to reapply the checks.\n\n"
+            (with-output-to-string
+              (pp (read (format "(%s)" (tramp-cache-print cache))))))
+           (write-region
+            (point-min) (point-max) tramp-persistency-file-name))))
+    (error nil)))
+
+(add-hook 'kill-emacs-hook 'tramp-dump-connection-properties)
+(add-hook 'tramp-cache-unload-hook
+         '(lambda ()
+            (remove-hook 'kill-emacs-hook
+                         'tramp-dump-connection-properties)))
+
+(defun tramp-parse-connection-properties (method)
+  "Return a list of (user host) tuples allowed to access for METHOD.
+This function is added always in `tramp-get-completion-function'
+for all methods.  Resulting data are derived from connection
+history."
+  (let (res)
+    (maphash
+     '(lambda (key value)
+       (if (and (vectorp key)
+                (string-equal method (tramp-file-name-method key))
+                (not (tramp-file-name-localname key)))
+           (push (list (tramp-file-name-user key)
+                       (tramp-file-name-host key))
+                 res)))
+     tramp-cache-data)
+    res))
+
+;; Read persistent connection history.  Applied with
+;; `load-in-progress', because it shall be evaluated only once.
+(when load-in-progress
+  (condition-case err
+      (with-temp-buffer
+       (insert-file-contents tramp-persistency-file-name)
+       (let ((list (read (current-buffer)))
+             element key item)
+         (while (setq element (pop list))
+           (setq key (pop element))
+           (while (setq item (pop element))
+             (tramp-set-connection-property key (pop item) (car item))))))
+    (file-error
+     ;; Most likely because the file doesn't exist yet.  No message.
+     (clrhash tramp-cache-data))
+    (error
+     ;; File is corrupted.
+     (message "%s" (error-message-string err))
+     (clrhash tramp-cache-data))))
+
+(provide 'tramp-cache)
+
+;;; tramp-cache.el ends here