summaryrefslogtreecommitdiff
path: root/lisp/net/tramp-rclone.el
blob: 96f7d9a89b98db0353c1bb11410ca4c91b0d490c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
;;; tramp-rclone.el --- Tramp access functions to cloud storages  -*- lexical-binding:t -*-

;; Copyright (C) 2018-2021 Free Software Foundation, Inc.

;; Author: Michael Albinus <michael.albinus@gmx.de>
;; Keywords: comm, processes
;; Package: tramp

;; 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.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; rclone is a command line program to sync files and directories to
;; and from cloud storages.  Tramp uses its mount utility to access
;; files and directories there.  The configuration of rclone for
;; different storage systems is performed outside Tramp, see rclone(1).

;; A remote file under rclone control has the form
;; "/rclone:<remote>:/path/to/file".  <remote> is the name of a
;; storage system in rclone's configuration.  Therefore, such a remote
;; file name does not know of any user or port specification.

;;; Code:

(eval-when-compile (require 'cl-lib))
(require 'tramp)

;;;###tramp-autoload
(defconst tramp-rclone-method "rclone"
  "When this method name is used, forward all calls to rclone mounts.")

;;;###tramp-autoload
(defcustom tramp-rclone-program "rclone"
  "Name of the rclone program."
  :group 'tramp
  :version "27.1"
  :type 'string)

;;;###tramp-autoload
(tramp--with-startup
 (add-to-list 'tramp-methods
	      `(,tramp-rclone-method
		(tramp-mount-args nil)
		(tramp-copyto-args nil)
		(tramp-moveto-args nil)
		(tramp-about-args ("--full"))))

 (add-to-list 'tramp-default-host-alist `(,tramp-rclone-method nil ""))

 (tramp-set-completion-function
  tramp-rclone-method '((tramp-rclone-parse-device-names ""))))


;; New handlers should be added here.
;;;###tramp-autoload
(defconst tramp-rclone-file-name-handler-alist
  '((access-file . tramp-handle-access-file)
    (add-name-to-file . tramp-handle-add-name-to-file)
    ;; `byte-compiler-base-file-name' performed by default handler.
    (copy-directory . tramp-handle-copy-directory)
    (copy-file . tramp-rclone-handle-copy-file)
    (delete-directory . tramp-rclone-handle-delete-directory)
    (delete-file . tramp-rclone-handle-delete-file)
    ;; `diff-latest-backup-file' performed by default handler.
    (directory-file-name . tramp-handle-directory-file-name)
    (directory-files . tramp-rclone-handle-directory-files)
    (directory-files-and-attributes
     . tramp-handle-directory-files-and-attributes)
    (dired-compress-file . ignore)
    (dired-uncache . tramp-handle-dired-uncache)
    (exec-path . ignore)
    (expand-file-name . tramp-handle-expand-file-name)
    (file-accessible-directory-p . tramp-handle-file-accessible-directory-p)
    (file-acl . ignore)
    (file-attributes . tramp-rclone-handle-file-attributes)
    (file-directory-p . tramp-handle-file-directory-p)
    (file-equal-p . tramp-handle-file-equal-p)
    (file-executable-p . tramp-rclone-handle-file-executable-p)
    (file-exists-p . tramp-handle-file-exists-p)
    (file-in-directory-p . tramp-handle-file-in-directory-p)
    (file-local-copy . tramp-handle-file-local-copy)
    (file-modes . tramp-handle-file-modes)
    (file-name-all-completions . tramp-rclone-handle-file-name-all-completions)
    (file-name-as-directory . tramp-handle-file-name-as-directory)
    (file-name-case-insensitive-p . tramp-handle-file-name-case-insensitive-p)
    (file-name-completion . tramp-handle-file-name-completion)
    (file-name-directory . tramp-handle-file-name-directory)
    (file-name-nondirectory . tramp-handle-file-name-nondirectory)
    ;; `file-name-sans-versions' performed by default handler.
    (file-newer-than-file-p . tramp-handle-file-newer-than-file-p)
    (file-notify-add-watch . ignore)
    (file-notify-rm-watch . ignore)
    (file-notify-valid-p . ignore)
    (file-ownership-preserved-p . ignore)
    (file-readable-p . tramp-rclone-handle-file-readable-p)
    (file-regular-p . tramp-handle-file-regular-p)
    (file-remote-p . tramp-handle-file-remote-p)
    (file-selinux-context . tramp-handle-file-selinux-context)
    (file-symlink-p . tramp-handle-file-symlink-p)
    (file-system-info . tramp-rclone-handle-file-system-info)
    (file-truename . tramp-handle-file-truename)
    (file-writable-p . tramp-handle-file-writable-p)
    (find-backup-file-name . tramp-handle-find-backup-file-name)
    ;; `get-file-buffer' performed by default handler.
    (insert-directory . tramp-handle-insert-directory)
    (insert-file-contents . tramp-handle-insert-file-contents)
    (load . tramp-handle-load)
    (make-auto-save-file-name . tramp-handle-make-auto-save-file-name)
    (make-directory . tramp-rclone-handle-make-directory)
    (make-directory-internal . ignore)
    (make-nearby-temp-file . tramp-handle-make-nearby-temp-file)
    (make-process . ignore)
    (make-symbolic-link . tramp-handle-make-symbolic-link)
    (process-file . ignore)
    (rename-file . tramp-rclone-handle-rename-file)
    (set-file-acl . ignore)
    (set-file-modes . ignore)
    (set-file-selinux-context . ignore)
    (set-file-times . ignore)
    (set-visited-file-modtime . tramp-handle-set-visited-file-modtime)
    (shell-command . ignore)
    (start-file-process . ignore)
    (substitute-in-file-name . tramp-handle-substitute-in-file-name)
    (temporary-file-directory . tramp-handle-temporary-file-directory)
    (tramp-get-remote-gid . ignore)
    (tramp-get-remote-uid . ignore)
    (tramp-set-file-uid-gid . ignore)
    (unhandled-file-name-directory . ignore)
    (vc-registered . ignore)
    (verify-visited-file-modtime . tramp-handle-verify-visited-file-modtime)
    (write-region . tramp-handle-write-region))
  "Alist of handler functions for Tramp RCLONE method.
Operations not mentioned here will be handled by the default Emacs primitives.")

;; It must be a `defsubst' in order to push the whole code into
;; tramp-loaddefs.el.  Otherwise, there would be recursive autoloading.
;;;###tramp-autoload
(defsubst tramp-rclone-file-name-p (filename)
  "Check if it's a FILENAME for rclone."
  (and (tramp-tramp-file-p filename)
       (string= (tramp-file-name-method (tramp-dissect-file-name filename))
		tramp-rclone-method)))

;;;###tramp-autoload
(defun tramp-rclone-file-name-handler (operation &rest args)
  "Invoke the rclone handler for OPERATION and ARGS.
First arg specifies the OPERATION, second arg is a list of
arguments to pass to the OPERATION."
  (if-let ((fn (assoc operation tramp-rclone-file-name-handler-alist)))
      (save-match-data (apply (cdr fn) args))
    (tramp-run-real-handler operation args)))

;;;###tramp-autoload
(tramp--with-startup
 (tramp-register-foreign-file-name-handler
  #'tramp-rclone-file-name-p #'tramp-rclone-file-name-handler))

;;;###tramp-autoload
(defun tramp-rclone-parse-device-names (_ignore)
  "Return a list of (nil host) tuples allowed to access."
  (with-tramp-connection-property nil "rclone-device-names"
    (delq nil
	  (mapcar
	   (lambda (line)
	     (when (string-match "^\\(\\S-+\\):$" line)
	       `(nil ,(match-string 1 line))))
	   (tramp-process-lines nil tramp-rclone-program "listremotes")))))


;; File name primitives.

(defun tramp-rclone-do-copy-or-rename-file
  (op filename newname &optional ok-if-already-exists keep-date
   preserve-uid-gid preserve-extended-attributes)
  "Copy or rename a remote file.
OP must be `copy' or `rename' and indicates the operation to perform.
FILENAME specifies the file to copy or rename, NEWNAME is the name of
the new file (for copy) or the new name of the file (for rename).
OK-IF-ALREADY-EXISTS means don't barf if NEWNAME exists already.
KEEP-DATE means to make sure that NEWNAME has the same timestamp
as FILENAME.  PRESERVE-UID-GID, when non-nil, instructs to keep
the uid and gid if both files are on the same host.
PRESERVE-EXTENDED-ATTRIBUTES is ignored.

This function is invoked by `tramp-rclone-handle-copy-file' and
`tramp-rclone-handle-rename-file'.  It is an error if OP is neither
of `copy' and `rename'.  FILENAME and NEWNAME must be absolute
file names."
  (unless (memq op '(copy rename))
    (error "Unknown operation `%s', must be `copy' or `rename'" op))

  (setq filename (file-truename filename))
  (if (file-directory-p filename)
      (progn
	(copy-directory filename newname keep-date t)
	(when (eq op 'rename) (delete-directory filename 'recursive)))

    (let ((t1 (tramp-tramp-file-p filename))
	  (t2 (tramp-tramp-file-p newname))
	  (rclone-operation (if (eq op 'copy) "copyto" "moveto"))
	  (msg-operation (if (eq op 'copy) "Copying" "Renaming")))

      (with-parsed-tramp-file-name (if t1 filename newname) nil
	(unless (file-exists-p filename)
	  (tramp-compat-file-missing v filename))
	(when (and (not ok-if-already-exists) (file-exists-p newname))
	  (tramp-error v 'file-already-exists newname))
	(when (and (file-directory-p newname)
		   (not (directory-name-p newname)))
	  (tramp-error v 'file-error "File is a directory %s" newname))

	(if (or (and t1 (not (tramp-rclone-file-name-p filename)))
		(and t2 (not (tramp-rclone-file-name-p newname))))

	    ;; We cannot copy or rename directly.
	    (let ((tmpfile (tramp-compat-make-temp-file filename)))
	      (if (eq op 'copy)
		  (copy-file
		   filename tmpfile t keep-date preserve-uid-gid
		   preserve-extended-attributes)
		(rename-file filename tmpfile t))
	      (rename-file tmpfile newname ok-if-already-exists))

	  ;; Direct action.
	  (with-tramp-progress-reporter
	      v 0 (format "%s %s to %s" msg-operation filename newname)
	    (unless (zerop
		     (tramp-rclone-send-command
		      v rclone-operation
		      (tramp-rclone-remote-file-name filename)
		      (tramp-rclone-remote-file-name newname)))
	      (tramp-error
	       v 'file-error
	       "Error %s `%s' `%s'" msg-operation filename newname)))

	  (when (and t1 (eq op 'rename))
	    (with-parsed-tramp-file-name filename v1
	      (tramp-flush-file-properties v1 v1-localname)
	      (when (tramp-rclone-file-name-p filename)
		(tramp-rclone-flush-directory-cache v1)
		;; The mount point's directory cache might need time
		;; to flush.
		(while (file-exists-p filename)
		  (tramp-flush-file-properties v1 v1-localname)))))

	  (when t2
	    (with-parsed-tramp-file-name newname v2
	      (tramp-flush-file-properties v2 v2-localname)
	      (when (tramp-rclone-file-name-p newname)
		(tramp-rclone-flush-directory-cache v2)
		;; The mount point's directory cache might need time
		;; to flush.
		(while (not (file-exists-p newname))
		  (tramp-flush-file-properties v2 v2-localname))))))))))

(defun tramp-rclone-handle-copy-file
  (filename newname &optional ok-if-already-exists keep-date
   preserve-uid-gid preserve-extended-attributes)
  "Like `copy-file' for Tramp files."
  (setq filename (expand-file-name filename)
	newname (expand-file-name newname))
  ;; At least one file a Tramp file?
  (if (or (tramp-tramp-file-p filename)
	  (tramp-tramp-file-p newname))
      (tramp-rclone-do-copy-or-rename-file
       'copy filename newname ok-if-already-exists keep-date
       preserve-uid-gid preserve-extended-attributes)
    (tramp-run-real-handler
     #'copy-file
     (list filename newname ok-if-already-exists keep-date
	   preserve-uid-gid preserve-extended-attributes))))

(defun tramp-rclone-handle-delete-directory
    (directory &optional recursive trash)
  "Like `delete-directory' for Tramp files."
  (with-parsed-tramp-file-name (expand-file-name directory) nil
    (tramp-flush-directory-properties v localname)
    (tramp-rclone-flush-directory-cache v)
    (delete-directory (tramp-rclone-local-file-name directory) recursive trash)))

(defun tramp-rclone-handle-delete-file (filename &optional trash)
  "Like `delete-file' for Tramp files."
  (with-parsed-tramp-file-name (expand-file-name filename) nil
    (tramp-rclone-flush-directory-cache v)
    (delete-file (tramp-rclone-local-file-name filename) trash)
    (tramp-flush-file-properties v localname)))

(defun tramp-rclone-handle-directory-files
    (directory &optional full match nosort count)
  "Like `directory-files' for Tramp files."
  (unless (file-exists-p directory)
    (tramp-compat-file-missing (tramp-dissect-file-name directory) directory))
  (when (file-directory-p directory)
    (setq directory (file-name-as-directory (expand-file-name directory)))
    (with-parsed-tramp-file-name directory nil
      (let ((result
	     (tramp-compat-directory-files
	      (tramp-rclone-local-file-name directory) full match nosort count)))
	;; Massage the result.
	(when full
	  (let ((local (concat "^" (regexp-quote (tramp-rclone-mount-point v))))
		(remote (funcall (if (tramp-compat-file-name-quoted-p directory)
				     #'tramp-compat-file-name-quote #'identity)
				 (file-remote-p directory))))
	    (setq result
		  (mapcar
		   (lambda (x) (replace-regexp-in-string local remote x))
		   result))))
	;; Some storage systems do not return "." and "..".
	(dolist (item '(".." "."))
	  (when (and (string-match-p (or match (regexp-quote item)) item)
		     (not
		      (member (if full (setq item (concat directory item)) item)
			      result)))
	    (setq result (cons item result))))
	;; Return result.
	(if nosort result (sort result #'string<))))))

(defun tramp-rclone-handle-file-attributes (filename &optional id-format)
  "Like `file-attributes' for Tramp files."
  (with-parsed-tramp-file-name (expand-file-name filename) nil
    (with-tramp-file-property
	v localname (format "file-attributes-%s" id-format)
      (file-attributes (tramp-rclone-local-file-name filename) id-format))))

(defun tramp-rclone-handle-file-executable-p (filename)
  "Like `file-executable-p' for Tramp files."
  (with-parsed-tramp-file-name (expand-file-name filename) nil
    (with-tramp-file-property v localname "file-executable-p"
      (file-executable-p (tramp-rclone-local-file-name filename)))))

(defun tramp-rclone-handle-file-name-all-completions (filename directory)
  "Like `file-name-all-completions' for Tramp files."
  (all-completions
   filename
   (delete-dups
    (append
     (file-name-all-completions
      filename (tramp-rclone-local-file-name directory))
     ;; Some storage systems do not return "." and "..".
     (let (result)
       (dolist (item '(".." ".") result)
	 (when (string-prefix-p filename item)
	   (catch 'match
	     (dolist (elt completion-regexp-list)
	       (unless (string-match-p elt item) (throw 'match nil)))
	     (setq result (cons (concat item "/") result))))))))))

(defun tramp-rclone-handle-file-readable-p (filename)
  "Like `file-readable-p' for Tramp files."
  (with-parsed-tramp-file-name (expand-file-name filename) nil
    (with-tramp-file-property v localname "file-readable-p"
      (file-readable-p (tramp-rclone-local-file-name filename)))))

(defun tramp-rclone-handle-file-system-info (filename)
  "Like `file-system-info' for Tramp files."
  (ignore-errors
    (unless (file-directory-p filename)
      (setq filename (file-name-directory filename)))
    (with-parsed-tramp-file-name (expand-file-name filename) nil
      (tramp-message v 5 "file system info: %s" localname)
      (tramp-rclone-send-command v "about" (concat host ":"))
      (with-current-buffer (tramp-get-connection-buffer v)
	(let (total used free)
	  (goto-char (point-min))
	  (while (not (eobp))
	    (when (looking-at "Total: [[:space:]]+\\([[:digit:]]+\\)")
	      (setq total (string-to-number (match-string 1))))
	    (when (looking-at "Used: [[:space:]]+\\([[:digit:]]+\\)")
	      (setq used (string-to-number (match-string 1))))
	    (when (looking-at "Free: [[:space:]]+\\([[:digit:]]+\\)")
	      (setq free (string-to-number (match-string 1))))
	    (forward-line))
	  (when used
	    ;; The used number of bytes is not part of the result.  As
	    ;; side effect, we store it as file property.
	    (tramp-set-file-property v localname "used-bytes" used))
	  ;; Result.
	  (when (and total free)
	    (list total free (- total free))))))))

(defun tramp-rclone-handle-insert-directory
  (filename switches &optional wildcard full-directory-p)
  "Like `insert-directory' for Tramp files."
  (insert-directory
   (tramp-rclone-local-file-name filename) switches wildcard full-directory-p)
  (goto-char (point-min))
  (while (search-forward (tramp-rclone-local-file-name filename) nil 'noerror)
    (replace-match filename)))

(defun tramp-rclone-handle-insert-file-contents
  (filename &optional visit beg end replace)
  "Like `insert-file-contents' for Tramp files."
  (let ((result
	 (insert-file-contents
	  (tramp-rclone-local-file-name filename) visit beg end replace)))
    (prog1
	(list (expand-file-name filename) (cadr result))
      (when visit (setq buffer-file-name filename)))))

(defun tramp-rclone-handle-make-directory (dir &optional parents)
  "Like `make-directory' for Tramp files."
  (with-parsed-tramp-file-name (expand-file-name dir) nil
    (make-directory (tramp-rclone-local-file-name dir) parents)
    ;; When PARENTS is non-nil, DIR could be a chain of non-existent
    ;; directories a/b/c/...  Instead of checking, we simply flush the
    ;; whole file cache.
    (tramp-flush-file-properties v localname)
    (tramp-flush-directory-properties
     v (if parents "/" (file-name-directory localname)))
    (tramp-rclone-flush-directory-cache v)))

(defun tramp-rclone-handle-rename-file
  (filename newname &optional ok-if-already-exists)
  "Like `rename-file' for Tramp files."
  (setq filename (expand-file-name filename)
	newname (expand-file-name newname))
  ;; At least one file a Tramp file?
  (if (or (tramp-tramp-file-p filename)
          (tramp-tramp-file-p newname))
      (tramp-rclone-do-copy-or-rename-file
       'rename filename newname ok-if-already-exists
       'keep-date 'preserve-uid-gid)
    (tramp-run-real-handler
     #'rename-file (list filename newname ok-if-already-exists))))


;; File name conversions.

(defun tramp-rclone-mount-point (vec)
  "Return local mount point of VEC."
  (expand-file-name
   (concat
    tramp-temp-name-prefix (tramp-file-name-method vec)
    "." (tramp-file-name-host vec))
   (tramp-compat-temporary-file-directory)))

(defun tramp-rclone-mounted-p (vec)
  "Check, whether storage system determined by VEC is mounted."
  (when (tramp-get-connection-process vec)
    ;; We cannot use `with-connection-property', because we don't want
    ;; to cache a nil result.
    (or (tramp-get-connection-property
	 (tramp-get-connection-process vec) "mounted" nil)
	(let* ((default-directory (tramp-compat-temporary-file-directory))
	       (mount (shell-command-to-string "mount -t fuse.rclone")))
	  (tramp-message vec 6 "%s" "mount -t fuse.rclone")
	  (tramp-message vec 6 "\n%s" mount)
	  (tramp-set-connection-property
	   (tramp-get-connection-process vec) "mounted"
	   (when (string-match
		  (format
		   "^\\(%s:\\S-*\\)" (regexp-quote (tramp-file-name-host vec)))
		  mount)
	     (match-string 1 mount)))))))

(defun tramp-rclone-flush-directory-cache (vec)
  "Flush directory cache of VEC mount."
  (let ((rclone-pid
	 ;; Identify rclone process.
	 (when (tramp-get-connection-process vec)
	   (with-tramp-connection-property
	       (tramp-get-connection-process vec) "rclone-pid"
	     (catch 'pid
	       (dolist
		   (pid
		    ;; Until Emacs 25, `process-attributes' could
		    ;; crash Emacs for some processes.  So we use
		    ;; "pidof", which might not work everywhere.
		    (if (<= emacs-major-version 25)
			(let ((default-directory
				(tramp-compat-temporary-file-directory)))
			  (mapcar
			   #'string-to-number
			   (split-string
			    (shell-command-to-string "pidof rclone"))))
		      (list-system-processes)))
		 (and (string-match-p
		       (regexp-quote
			(format "rclone mount %s:" (tramp-file-name-host vec)))
		       (or (cdr (assoc 'args (process-attributes pid))) ""))
		      (throw 'pid pid))))))))
    ;; Send a SIGHUP in order to flush directory cache.
    (when rclone-pid
      (tramp-message
       vec 6 "Send SIGHUP %d: %s"
       rclone-pid (cdr (assoc 'args (process-attributes rclone-pid))))
      (signal-process rclone-pid 'SIGHUP))))

(defun tramp-rclone-local-file-name (filename)
  "Return local mount name of FILENAME."
  (setq filename (tramp-compat-file-name-unquote (expand-file-name filename)))
  (with-parsed-tramp-file-name filename nil
    ;; As long as we call `tramp-rclone-maybe-open-connection' here,
    ;; we cache the result.
    (with-tramp-file-property v localname "local-file-name"
      (tramp-rclone-maybe-open-connection v)
      (let ((quoted (tramp-compat-file-name-quoted-p localname))
	    (localname (tramp-compat-file-name-unquote localname)))
	(funcall
	 (if quoted #'tramp-compat-file-name-quote #'identity)
	 (expand-file-name
	  (if (file-name-absolute-p localname)
	      (substring localname 1) localname)
	  (tramp-rclone-mount-point v)))))))

(defun tramp-rclone-remote-file-name (filename)
  "Return FILENAME as used in the `rclone' command."
  (setq filename (tramp-compat-file-name-unquote (expand-file-name filename)))
  (if (tramp-rclone-file-name-p filename)
      (with-parsed-tramp-file-name filename nil
	;; As long as we call `tramp-rclone-maybe-open-connection' here,
	;; we cache the result.
	(with-tramp-file-property v localname "remote-file-name"
	  (tramp-rclone-maybe-open-connection v)
	  ;; TODO: This shall be handled by `expand-file-name'.
	  (setq localname
		(replace-regexp-in-string "^\\." "" (or localname "")))
	  (format "%s%s" (tramp-rclone-mounted-p v) localname)))
    ;; It is a local file name.
    filename))

(defun tramp-rclone-maybe-open-connection (vec)
  "Maybe open a connection VEC.
Does not do anything if a connection is already open, but re-opens the
connection if a previous connection has died for some reason."
  ;; During completion, don't reopen a new connection.
  (unless (tramp-connectable-p vec)
    (throw 'non-essential 'non-essential))

  (let ((host (tramp-file-name-host vec)))
    (when (rassoc `(,host) (tramp-rclone-parse-device-names nil))
      (if (zerop (length host))
	  (tramp-error vec 'file-error "Storage %s not connected" host))
      ;; We need a process bound to the connection buffer.  Therefore,
      ;; we create a dummy process.  Maybe there is a better solution?
      (unless (get-buffer-process (tramp-get-connection-buffer vec))
	(let ((p (make-network-process
		  :name (tramp-get-connection-name vec)
		  :buffer (tramp-get-connection-buffer vec)
		  :server t :host 'local :service t :noquery t)))
	  (process-put p 'vector vec)
	  (set-process-query-on-exit-flag p nil)

	  ;; Set connection-local variables.
	  (tramp-set-connection-local-variables vec)))

      ;; Create directory.
      (unless (file-directory-p (tramp-rclone-mount-point vec))
	(make-directory (tramp-rclone-mount-point vec) 'parents))

      ;; Mount.  This command does not return, so we use 0 as
      ;; DESTINATION of `tramp-call-process'.
      (unless (tramp-rclone-mounted-p vec)
	(apply
	 #'tramp-call-process
	 vec tramp-rclone-program nil 0 nil
	 (delq nil
	       `("mount" ,(concat host ":/")
		 ,(tramp-rclone-mount-point vec)
		 ;; This could be nil.
		 ,(tramp-get-method-parameter vec 'tramp-mount-args))))
	(while (not (file-exists-p (tramp-make-tramp-file-name vec 'noloc)))
	  (tramp-cleanup-connection vec 'keep-debug 'keep-password))

	;; Mark it as connected.
	(tramp-set-connection-property
	 (tramp-get-connection-process vec) "connected" t))))

  ;; In `tramp-check-cached-permissions', the connection properties
  ;; "{uid,gid}-{integer,string}" are used.  We set them to proper values.
  (with-tramp-connection-property
      vec "uid-integer" (tramp-get-local-uid 'integer))
  (with-tramp-connection-property
      vec "gid-integer" (tramp-get-local-gid 'integer))
  (with-tramp-connection-property
      vec "uid-string" (tramp-get-local-uid 'string))
  (with-tramp-connection-property
      vec "gid-string" (tramp-get-local-gid 'string)))

(defun tramp-rclone-send-command (vec &rest args)
  "Send a command to connection VEC.
The command is the list of strings ARGS."
  (with-current-buffer (tramp-get-connection-buffer vec)
    (erase-buffer)
    (let ((flags (tramp-get-method-parameter
		  vec (intern (format "tramp-%s-args" (car args))))))
      (apply #'tramp-call-process
	     vec tramp-rclone-program nil t nil (append args flags)))))

(add-hook 'tramp-unload-hook
	  (lambda ()
	    (unload-feature 'tramp-rclone 'force)))

(provide 'tramp-rclone)

;;; TODO:

;; * If possible, get rid of "rclone mount".  Maybe it is more
;;   performant then.

;;; tramp-rclone.el ends here