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1 ;;; tramp-cache.el --- file information caching for Tramp
2
3 ;; Copyright (C) 2000, 2005-2014 Free Software Foundation, Inc.
4
5 ;; Author: Daniel Pittman <daniel@inanna.danann.net>
6 ;; Michael Albinus <michael.albinus@gmx.de>
7 ;; Keywords: comm, processes
8 ;; Package: tramp
9
10 ;; This file is part of GNU Emacs.
11
12 ;; GNU Emacs is free software: you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation, either version 3 of the License, or
15 ;; (at your option) any later version.
16
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
21
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
24
25 ;;; Commentary:
26
27 ;; An implementation of information caching for remote files.
28
29 ;; Each connection, identified by a vector [method user host
30 ;; localname] or by a process, has a unique cache. We distinguish 3
31 ;; kind of caches, depending on the key:
32 ;;
33 ;; - localname is NIL. This are reusable properties. Examples:
34 ;; "remote-shell" identifies the POSIX shell to be called on the
35 ;; remote host, or "perl" is the command to be called on the remote
36 ;; host when starting a Perl script. These properties are saved in
37 ;; the file `tramp-persistency-file-name'.
38 ;;
39 ;; - localname is a string. This are temporary properties, which are
40 ;; related to the file localname is referring to. Examples:
41 ;; "file-exists-p" is t or nil, depending on the file existence, or
42 ;; "file-attributes" caches the result of the function
43 ;; `file-attributes'. These entries have a timestamp, and they
44 ;; expire after `remote-file-name-inhibit-cache' seconds if this
45 ;; variable is set.
46 ;;
47 ;; - The key is a process. This are temporary properties related to
48 ;; an open connection. Examples: "scripts" keeps shell script
49 ;; definitions already sent to the remote shell, "last-cmd-time" is
50 ;; the time stamp a command has been sent to the remote process.
51
52 ;;; Code:
53
54 (require 'tramp)
55 (autoload 'time-stamp-string "time-stamp")
56
57 ;;; -- Cache --
58
59 ;;;###tramp-autoload
60 (defvar tramp-cache-data (make-hash-table :test 'equal)
61 "Hash table for remote files properties.")
62
63 ;;;###tramp-autoload
64 (defcustom tramp-connection-properties nil
65 "List of static connection properties.
66 Every entry has the form (REGEXP PROPERTY VALUE). The regexp
67 matches remote file names. It can be nil. PROPERTY is a string,
68 and VALUE the corresponding value. They are used, if there is no
69 matching entry for PROPERTY in `tramp-cache-data'."
70 :group 'tramp
71 :version "24.4"
72 :type '(repeat (list (choice :tag "File Name regexp" regexp (const nil))
73 (choice :tag " Property" string)
74 (choice :tag " Value" sexp))))
75
76 (defcustom tramp-persistency-file-name
77 (cond
78 ;; GNU Emacs.
79 ((and (fboundp 'locate-user-emacs-file))
80 (expand-file-name (tramp-compat-funcall 'locate-user-emacs-file "tramp")))
81 ((and (boundp 'user-emacs-directory)
82 (stringp (symbol-value 'user-emacs-directory))
83 (file-directory-p (symbol-value 'user-emacs-directory)))
84 (expand-file-name "tramp" (symbol-value 'user-emacs-directory)))
85 ((and (not (featurep 'xemacs)) (file-directory-p "~/.emacs.d/"))
86 "~/.emacs.d/tramp")
87 ;; XEmacs.
88 ((and (boundp 'user-init-directory)
89 (stringp (symbol-value 'user-init-directory))
90 (file-directory-p (symbol-value 'user-init-directory)))
91 (expand-file-name "tramp" (symbol-value 'user-init-directory)))
92 ((and (featurep 'xemacs) (file-directory-p "~/.xemacs/"))
93 "~/.xemacs/tramp")
94 ;; For users without `~/.emacs.d/' or `~/.xemacs/'.
95 (t "~/.tramp"))
96 "File which keeps connection history for Tramp connections."
97 :group 'tramp
98 :type 'file)
99
100 (defvar tramp-cache-data-changed nil
101 "Whether persistent cache data have been changed.")
102
103 (defun tramp-get-hash-table (key)
104 "Returns the hash table for KEY.
105 If it doesn't exist yet, it is created and initialized with
106 matching entries of `tramp-connection-properties'."
107 (or (gethash key tramp-cache-data)
108 (let ((hash
109 (puthash key (make-hash-table :test 'equal) tramp-cache-data)))
110 (when (vectorp key)
111 (dolist (elt tramp-connection-properties)
112 (when (string-match
113 (or (nth 0 elt) "")
114 (tramp-make-tramp-file-name
115 (aref key 0) (aref key 1) (aref key 2) nil))
116 (tramp-set-connection-property key (nth 1 elt) (nth 2 elt)))))
117 hash)))
118
119 ;;;###tramp-autoload
120 (defun tramp-get-file-property (key file property default)
121 "Get the PROPERTY of FILE from the cache context of KEY.
122 Returns DEFAULT if not set."
123 ;; Unify localname.
124 (setq key (copy-sequence key))
125 (aset key 3 (tramp-run-real-handler 'directory-file-name (list file)))
126 (let* ((hash (tramp-get-hash-table key))
127 (value (when (hash-table-p hash) (gethash property hash))))
128 (if
129 ;; We take the value only if there is any, and
130 ;; `remote-file-name-inhibit-cache' indicates that it is still
131 ;; valid. Otherwise, DEFAULT is set.
132 (and (consp value)
133 (or (null remote-file-name-inhibit-cache)
134 (and (integerp remote-file-name-inhibit-cache)
135 (<=
136 (tramp-time-diff (current-time) (car value))
137 remote-file-name-inhibit-cache))
138 (and (consp remote-file-name-inhibit-cache)
139 (tramp-time-less-p
140 remote-file-name-inhibit-cache (car value)))))
141 (setq value (cdr value))
142 (setq value default))
143
144 (tramp-message key 8 "%s %s %s" file property value)
145 (when (>= tramp-verbose 10)
146 (let* ((var (intern (concat "tramp-cache-get-count-" property)))
147 (val (or (ignore-errors (symbol-value var)) 0)))
148 (set var (1+ val))))
149 value))
150
151 ;;;###tramp-autoload
152 (defun tramp-set-file-property (key file property value)
153 "Set the PROPERTY of FILE to VALUE, in the cache context of KEY.
154 Returns VALUE."
155 ;; Unify localname.
156 (setq key (copy-sequence key))
157 (aset key 3 (tramp-run-real-handler 'directory-file-name (list file)))
158 (let ((hash (tramp-get-hash-table key)))
159 ;; We put the timestamp there.
160 (puthash property (cons (current-time) value) hash)
161 (tramp-message key 8 "%s %s %s" file property value)
162 (when (>= tramp-verbose 10)
163 (let* ((var (intern (concat "tramp-cache-set-count-" property)))
164 (val (or (ignore-errors (symbol-value var)) 0)))
165 (set var (1+ val))))
166 value))
167
168 ;;;###tramp-autoload
169 (defun tramp-flush-file-property (key file)
170 "Remove all properties of FILE in the cache context of KEY."
171 ;; Remove file properties of symlinks.
172 (let ((truename (tramp-get-file-property key file "file-truename" nil)))
173 (when (and (stringp truename)
174 (not (string-equal file truename)))
175 (tramp-flush-file-property key truename)))
176 ;; Unify localname.
177 (setq key (copy-sequence key))
178 (aset key 3 (tramp-run-real-handler 'directory-file-name (list file)))
179 (tramp-message key 8 "%s" file)
180 (remhash key tramp-cache-data))
181
182 ;;;###tramp-autoload
183 (defun tramp-flush-directory-property (key directory)
184 "Remove all properties of DIRECTORY in the cache context of KEY.
185 Remove also properties of all files in subdirectories."
186 (let* ((directory (tramp-run-real-handler
187 'directory-file-name (list directory)))
188 (truename (tramp-get-file-property key directory "file-truename" nil)))
189 ;; Remove file properties of symlinks.
190 (when (and (stringp truename)
191 (not (string-equal directory truename)))
192 (tramp-flush-directory-property key truename))
193 (tramp-message key 8 "%s" directory)
194 (maphash
195 (lambda (key _value)
196 (when (and (stringp (tramp-file-name-localname key))
197 (string-match directory (tramp-file-name-localname key)))
198 (remhash key tramp-cache-data)))
199 tramp-cache-data)))
200
201 ;; Reverting or killing a buffer should also flush file properties.
202 ;; They could have been changed outside Tramp. In eshell, "ls" would
203 ;; not show proper directory contents when a file has been copied or
204 ;; deleted before.
205 (defun tramp-flush-file-function ()
206 "Flush all Tramp cache properties from `buffer-file-name'."
207 (let ((bfn (if (stringp (buffer-file-name))
208 (buffer-file-name)
209 default-directory)))
210 (when (tramp-tramp-file-p bfn)
211 (with-parsed-tramp-file-name bfn nil
212 (tramp-flush-file-property v localname)))))
213
214 (add-hook 'before-revert-hook 'tramp-flush-file-function)
215 (add-hook 'eshell-pre-command-hook 'tramp-flush-file-function)
216 (add-hook 'kill-buffer-hook 'tramp-flush-file-function)
217 (add-hook 'tramp-cache-unload-hook
218 (lambda ()
219 (remove-hook 'before-revert-hook
220 'tramp-flush-file-function)
221 (remove-hook 'eshell-pre-command-hook
222 'tramp-flush-file-function)
223 (remove-hook 'kill-buffer-hook
224 'tramp-flush-file-function)))
225
226 ;;; -- Properties --
227
228 ;;;###tramp-autoload
229 (defun tramp-get-connection-property (key property default)
230 "Get the named PROPERTY for the connection.
231 KEY identifies the connection, it is either a process or a vector.
232 If the value is not set for the connection, returns DEFAULT."
233 ;; Unify key by removing localname from vector. Work with a copy in
234 ;; order to avoid side effects.
235 (when (vectorp key)
236 (setq key (copy-sequence key))
237 (aset key 3 nil))
238 (let* ((hash (tramp-get-hash-table key))
239 (value (if (hash-table-p hash)
240 (gethash property hash default)
241 default)))
242 (tramp-message key 7 "%s %s" property value)
243 value))
244
245 ;;;###tramp-autoload
246 (defun tramp-set-connection-property (key property value)
247 "Set the named PROPERTY of a connection to VALUE.
248 KEY identifies the connection, it is either a process or a vector.
249 PROPERTY is set persistent when KEY is a vector."
250 ;; Unify key by removing localname from vector. Work with a copy in
251 ;; order to avoid side effects.
252 (when (vectorp key)
253 (setq key (copy-sequence key))
254 (aset key 3 nil))
255 (let ((hash (tramp-get-hash-table key)))
256 (puthash property value hash)
257 (setq tramp-cache-data-changed t)
258 (tramp-message key 7 "%s %s" property value)
259 value))
260
261 ;;;###tramp-autoload
262 (defun tramp-connection-property-p (key property)
263 "Check whether named PROPERTY of a connection is defined.
264 KEY identifies the connection, it is either a process or a vector."
265 (not (eq (tramp-get-connection-property key property 'undef) 'undef)))
266
267 ;;;###tramp-autoload
268 (defun tramp-flush-connection-property (key)
269 "Remove all properties identified by KEY.
270 KEY identifies the connection, it is either a process or a vector."
271 ;; Unify key by removing localname from vector. Work with a copy in
272 ;; order to avoid side effects.
273 (when (vectorp key)
274 (setq key (copy-sequence key))
275 (aset key 3 nil))
276 (tramp-message
277 key 7 "%s %s" key
278 (let ((hash (gethash key tramp-cache-data))
279 properties)
280 (when (hash-table-p hash)
281 (maphash (lambda (x _y) (add-to-list 'properties x 'append)) hash))
282 properties))
283 (setq tramp-cache-data-changed t)
284 (remhash key tramp-cache-data))
285
286 ;;;###tramp-autoload
287 (defun tramp-cache-print (table)
288 "Print hash table TABLE."
289 (when (hash-table-p table)
290 (let (result)
291 (maphash
292 (lambda (key value)
293 ;; Remove text properties from KEY and VALUE.
294 ;; `substring-no-properties' does not exist in XEmacs.
295 (when (functionp 'substring-no-properties)
296 (when (vectorp key)
297 (dotimes (i (length key))
298 (when (stringp (aref key i))
299 (aset key i
300 (tramp-compat-funcall
301 'substring-no-properties (aref key i))))))
302 (when (stringp key)
303 (setq key (tramp-compat-funcall 'substring-no-properties key)))
304 (when (stringp value)
305 (setq value
306 (tramp-compat-funcall 'substring-no-properties value))))
307 ;; Dump.
308 (let ((tmp (format
309 "(%s %s)"
310 (if (processp key)
311 (prin1-to-string (prin1-to-string key))
312 (prin1-to-string key))
313 (if (hash-table-p value)
314 (tramp-cache-print value)
315 (if (bufferp value)
316 (prin1-to-string (prin1-to-string value))
317 (prin1-to-string value))))))
318 (setq result (if result (concat result " " tmp) tmp))))
319 table)
320 result)))
321
322 ;;;###tramp-autoload
323 (defun tramp-list-connections ()
324 "Return a list of all known connection vectors according to `tramp-cache'."
325 (let (result)
326 (maphash
327 (lambda (key _value)
328 (when (and (vectorp key) (null (aref key 3)))
329 (add-to-list 'result key)))
330 tramp-cache-data)
331 result))
332
333 (defun tramp-dump-connection-properties ()
334 "Write persistent connection properties into file `tramp-persistency-file-name'."
335 ;; We shouldn't fail, otherwise (X)Emacs might not be able to be closed.
336 (ignore-errors
337 (when (and (hash-table-p tramp-cache-data)
338 (not (zerop (hash-table-count tramp-cache-data)))
339 tramp-cache-data-changed
340 (stringp tramp-persistency-file-name))
341 (let ((cache (copy-hash-table tramp-cache-data))
342 print-length print-level)
343 ;; Remove temporary data. If there is the key "login-as", we
344 ;; don't save either, because all other properties might
345 ;; depend on the login name, and we want to give the
346 ;; possibility to use another login name later on.
347 (maphash
348 (lambda (key value)
349 (if (and (vectorp key)
350 (not (tramp-file-name-localname key))
351 (not (gethash "login-as" value)))
352 (progn
353 (remhash "process-name" value)
354 (remhash "process-buffer" value)
355 (remhash "first-password-request" value))
356 (remhash key cache)))
357 cache)
358 ;; Dump it.
359 (with-temp-buffer
360 (insert
361 ";; -*- emacs-lisp -*-"
362 ;; `time-stamp-string' might not exist in all (X)Emacs flavors.
363 (condition-case nil
364 (progn
365 (format
366 " <%s %s>\n"
367 (time-stamp-string "%02y/%02m/%02d %02H:%02M:%02S")
368 tramp-persistency-file-name))
369 (error "\n"))
370 ";; Tramp connection history. Don't change this file.\n"
371 ";; You can delete it, forcing Tramp to reapply the checks.\n\n"
372 (with-output-to-string
373 (pp (read (format "(%s)" (tramp-cache-print cache))))))
374 (write-region
375 (point-min) (point-max) tramp-persistency-file-name))))))
376
377 (unless noninteractive
378 (add-hook 'kill-emacs-hook 'tramp-dump-connection-properties))
379 (add-hook 'tramp-cache-unload-hook
380 (lambda ()
381 (remove-hook 'kill-emacs-hook
382 'tramp-dump-connection-properties)))
383
384 ;;;###tramp-autoload
385 (defun tramp-parse-connection-properties (method)
386 "Return a list of (user host) tuples allowed to access for METHOD.
387 This function is added always in `tramp-get-completion-function'
388 for all methods. Resulting data are derived from connection history."
389 (let (res)
390 (maphash
391 (lambda (key _value)
392 (if (and (vectorp key)
393 (string-equal method (tramp-file-name-method key))
394 (not (tramp-file-name-localname key)))
395 (push (list (tramp-file-name-user key)
396 (tramp-file-name-host key))
397 res)))
398 tramp-cache-data)
399 res))
400
401 ;; Read persistent connection history.
402 (when (and (stringp tramp-persistency-file-name)
403 (zerop (hash-table-count tramp-cache-data))
404 ;; When "emacs -Q" has been called, both variables are nil.
405 ;; We do not load the persistency file then, in order to
406 ;; have a clean test environment.
407 (or (and (boundp 'init-file-user) (symbol-value 'init-file-user))
408 (and (boundp 'site-run-file) (symbol-value 'site-run-file))))
409 (condition-case err
410 (with-temp-buffer
411 (insert-file-contents tramp-persistency-file-name)
412 (let ((list (read (current-buffer)))
413 (tramp-verbose 0)
414 element key item)
415 (while (setq element (pop list))
416 (setq key (pop element))
417 (while (setq item (pop element))
418 ;; We set only values which are not contained in
419 ;; `tramp-connection-properties'. The cache is
420 ;; initialized properly by side effect.
421 (unless (tramp-connection-property-p key (car item))
422 (tramp-set-connection-property key (pop item) (car item))))))
423 (setq tramp-cache-data-changed nil))
424 (file-error
425 ;; Most likely because the file doesn't exist yet. No message.
426 (clrhash tramp-cache-data))
427 (error
428 ;; File is corrupted.
429 (message "Tramp persistency file '%s' is corrupted: %s"
430 tramp-persistency-file-name (error-message-string err))
431 (clrhash tramp-cache-data))))
432
433 (add-hook 'tramp-unload-hook
434 (lambda ()
435 (unload-feature 'tramp-cache 'force)))
436
437 (provide 'tramp-cache)
438
439 ;;; tramp-cache.el ends here