unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
blob 302f52225ef56ad4b7641e01244c09f9dca456d3 13379 bytes (raw)
name: src/inotify.c 	 # note: path name is non-authoritative(*)

  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
 
/* Inotify support for Emacs

Copyright (C) 2012-2017 Free Software Foundation, Inc.

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 <http://www.gnu.org/licenses/>.  */

#include <config.h>

#ifdef HAVE_INOTIFY

#include "lisp.h"
#include "coding.h"
#include "process.h"
#include "keyboard.h"
#include "termhooks.h"

#include <errno.h>
#include <sys/inotify.h>
#include <sys/ioctl.h>

/* Ignore bits that might be undefined on old GNU/Linux systems.  */
#ifndef IN_EXCL_UNLINK
# define IN_EXCL_UNLINK 0
#endif
#ifndef IN_DONT_FOLLOW
# define IN_DONT_FOLLOW 0
#endif
#ifndef IN_ONLYDIR
# define IN_ONLYDIR 0
#endif

/* File handle for inotify.  */
static int inotifyfd = -1;

/* Assoc list of files being watched.
   Format: (watch-descriptor name callback)
 */
static Lisp_Object watch_list;

static Lisp_Object
add_watch_descriptor (int wd, Lisp_Object filename, Lisp_Object callback)
{
  Lisp_Object descriptor = make_number (wd);
  Lisp_Object elt = Fassoc (descriptor, watch_list);
  Lisp_Object list = Fcdr (elt);
  Lisp_Object watch, watch_id;
  int id = 0;

  while (! NILP (list))
    {
      id = max (id, 1 + XINT (XCAR (XCAR (list))));
      list = XCDR (list);
    }

  watch_id = make_number (id);
  watch = list3 (watch_id, filename, callback);

  if (NILP (elt))
    watch_list = Fcons (Fcons (descriptor, Fcons (watch, Qnil)),
                        watch_list);
  else
    XSETCDR (elt, Fcons (watch, XCDR (elt)));

  return Fcons (descriptor, watch_id);
}

static void
remove_watch_descriptor (Lisp_Object descriptor, Lisp_Object id)
{
  Lisp_Object watches = Fassoc (descriptor, watch_list);

  if (CONSP (watches))
    {
      Lisp_Object watch = Fassoc (id, XCDR (watches));

      if (CONSP (watch))
        XSETCDR (watches, Fdelete (watch, XCDR (watches)));

      if (NILP (XCDR (watches)))
        watch_list = Fdelete (watches, watch_list);
    }
}

static Lisp_Object
mask_to_aspects (uint32_t mask) {
  Lisp_Object aspects = Qnil;
  if (mask & IN_ACCESS)
    aspects = Fcons (Qaccess, aspects);
  if (mask & IN_ATTRIB)
    aspects = Fcons (Qattrib, aspects);
  if (mask & IN_CLOSE_WRITE)
    aspects = Fcons (Qclose_write, aspects);
  if (mask & IN_CLOSE_NOWRITE)
    aspects = Fcons (Qclose_nowrite, aspects);
  if (mask & IN_CREATE)
    aspects = Fcons (Qcreate, aspects);
  if (mask & IN_DELETE)
    aspects = Fcons (Qdelete, aspects);
  if (mask & IN_DELETE_SELF)
    aspects = Fcons (Qdelete_self, aspects);
  if (mask & IN_MODIFY)
    aspects = Fcons (Qmodify, aspects);
  if (mask & IN_MOVE_SELF)
    aspects = Fcons (Qmove_self, aspects);
  if (mask & IN_MOVED_FROM)
    aspects = Fcons (Qmoved_from, aspects);
  if (mask & IN_MOVED_TO)
    aspects = Fcons (Qmoved_to, aspects);
  if (mask & IN_OPEN)
    aspects = Fcons (Qopen,  aspects);
  if (mask & IN_IGNORED)
    aspects = Fcons (Qignored, aspects);
  if (mask & IN_ISDIR)
    aspects = Fcons (Qisdir, aspects);
  if (mask & IN_Q_OVERFLOW)
    aspects = Fcons (Qq_overflow, aspects);
  if (mask & IN_UNMOUNT)
    aspects = Fcons (Qunmount, aspects);
  return aspects;
}

static Lisp_Object
inotifyevent_to_event (Lisp_Object watch, struct inotify_event const *ev)
{
  Lisp_Object name = Qnil;
  if (ev->len > 0)
    {
      size_t const len = strlen (ev->name);
      name = make_unibyte_string (ev->name, min (len, ev->len));
      name = DECODE_FILE (name);
    }
  else
    name = XCAR (XCDR (watch));

  return list2 (list4 (Fcons (make_number (ev->wd), XCAR (watch)),
                       mask_to_aspects (ev->mask),
                       name,
                       make_number (ev->cookie)),
		Fnth (make_number (2), watch));
}

/* This callback is called when the FD is available for read.  The inotify
   events are read from FD and converted into input_events.  */
static void
inotify_callback (int fd, void *_)
{
  struct input_event event;
  int to_read;
  char *buffer;
  ssize_t n;
  size_t i;

  to_read = 0;
  if (ioctl (fd, FIONREAD, &to_read) == -1)
    report_file_notify_error ("Error while retrieving file system events",
			      Qnil);
  buffer = xmalloc (to_read);
  n = read (fd, buffer, to_read);
  if (n < 0)
    {
      xfree (buffer);
      report_file_notify_error ("Error while reading file system events", Qnil);
    }

  EVENT_INIT (event);
  event.kind = FILE_NOTIFY_EVENT;

  i = 0;
  while (i < (size_t)n)
    {
      struct inotify_event *ev = (struct inotify_event *) &buffer[i];
      Lisp_Object descriptor = make_number (ev->wd);
      Lisp_Object watches = Fassoc (descriptor, watch_list);

      if (CONSP (watches))
        {
          for (Lisp_Object elt = XCDR (watches); CONSP (elt); elt = XCDR (elt))
            {
              event.arg = inotifyevent_to_event (XCAR (elt), ev);

              if (!NILP (event.arg))
                kbd_buffer_store_event (&event);
            }
          /* If event was removed automatically: Drop it from watch list.  */
          if (ev->mask & IN_IGNORED)
            for (Lisp_Object elt = XCDR (watches); CONSP (elt); elt = XCDR (elt))
              remove_watch_descriptor (descriptor, XCAR (elt));
        }
      i += sizeof (*ev) + ev->len;
    }

  xfree (buffer);
}

static uint32_t
symbol_to_inotifymask (Lisp_Object symb)
{
  if (EQ (symb, Qaccess))
    return IN_ACCESS;
  else if (EQ (symb, Qattrib))
    return IN_ATTRIB;
  else if (EQ (symb, Qclose_write))
    return IN_CLOSE_WRITE;
  else if (EQ (symb, Qclose_nowrite))
    return IN_CLOSE_NOWRITE;
  else if (EQ (symb, Qcreate))
    return IN_CREATE;
  else if (EQ (symb, Qdelete))
    return IN_DELETE;
  else if (EQ (symb, Qdelete_self))
    return IN_DELETE_SELF;
  else if (EQ (symb, Qmodify))
    return IN_MODIFY;
  else if (EQ (symb, Qmove_self))
    return IN_MOVE_SELF;
  else if (EQ (symb, Qmoved_from))
    return IN_MOVED_FROM;
  else if (EQ (symb, Qmoved_to))
    return IN_MOVED_TO;
  else if (EQ (symb, Qopen))
    return IN_OPEN;
  else if (EQ (symb, Qmove))
    return IN_MOVE;
  else if (EQ (symb, Qclose))
    return IN_CLOSE;

  else if (EQ (symb, Qdont_follow))
    return IN_DONT_FOLLOW;
  else if (EQ (symb, Qexcl_unlink))
    return IN_EXCL_UNLINK;
  else if (EQ (symb, Qmask_add))
    return IN_MASK_ADD;
  else if (EQ (symb, Qoneshot))
    return IN_ONESHOT;
  else if (EQ (symb, Qonlydir))
    return IN_ONLYDIR;

  else if (EQ (symb, Qt) || EQ (symb, Qall_events))
    return IN_ALL_EVENTS;
  else
    {
      errno = EINVAL;
      report_file_notify_error ("Unknown aspect", symb);
    }
}

static uint32_t
aspect_to_inotifymask (Lisp_Object aspect)
{
  if (CONSP (aspect))
    {
      Lisp_Object x = aspect;
      uint32_t mask = 0;
      while (CONSP (x))
        {
          mask |= symbol_to_inotifymask (XCAR (x));
          x = XCDR (x);
        }
      return mask;
    }
  else
    return symbol_to_inotifymask (aspect);
}

DEFUN ("inotify-add-watch", Finotify_add_watch, Sinotify_add_watch, 3, 3, 0,
       doc: /* Add a watch for FILE-NAME to inotify.

Return a watch descriptor.  The watch will look for ASPECT events and
invoke CALLBACK when an event occurs.

ASPECT might be one of the following symbols or a list of those symbols:

access
attrib
close-write
close-nowrite
create
delete
delete-self
modify
move-self
moved-from
moved-to
open

all-events or t
move
close

The following symbols can also be added to a list of aspects:

dont-follow
excl-unlink
mask-add
oneshot
onlydir

Watching a directory is not recursive.  CALLBACK is passed a single argument
EVENT which contains an event structure of the format

\(WATCH-DESCRIPTOR ASPECTS NAME COOKIE)

WATCH-DESCRIPTOR is the same object that was returned by this function.  It can
be tested for equality using `equal'.  ASPECTS describes the event.  It is a
list of ASPECT symbols described above and can also contain one of the following
symbols

ignored
isdir
q-overflow
unmount

If a directory is watched then NAME is the name of file that caused the event.

COOKIE is an object that can be compared using `equal' to identify two matching
renames (moved-from and moved-to).

See inotify(7) and inotify_add_watch(2) for further information.  The inotify fd
is managed internally and there is no corresponding inotify_init.  Use
`inotify-rm-watch' to remove a watch.
            */)
     (Lisp_Object file_name, Lisp_Object aspect, Lisp_Object callback)
{
  uint32_t mask;
  Lisp_Object encoded_file_name;
  int wd = -1;

  CHECK_STRING (file_name);

  if (inotifyfd < 0)
    {
      inotifyfd = inotify_init1 (IN_NONBLOCK|IN_CLOEXEC);
      if (inotifyfd < 0)
	report_file_notify_error ("File watching is not available", Qnil);
      watch_list = Qnil;
      add_read_fd (inotifyfd, &inotify_callback, NULL);
    }

  mask = aspect_to_inotifymask (aspect);
  encoded_file_name = ENCODE_FILE (file_name);
  wd = inotify_add_watch (inotifyfd, SSDATA (encoded_file_name), mask);
  if (wd == -1)
    report_file_notify_error ("Could not add watch for file", file_name);

  return add_watch_descriptor (wd, file_name, callback);
}

DEFUN ("inotify-rm-watch", Finotify_rm_watch, Sinotify_rm_watch, 1, 1, 0,
       doc: /* Remove an existing WATCH-DESCRIPTOR.

WATCH-DESCRIPTOR should be an object returned by `inotify-add-watch'.

See inotify_rm_watch(2) for more information.
             */)
     (Lisp_Object watch_descriptor)
{

  Lisp_Object descriptor, id;

  if (! (CONSP (watch_descriptor)
         && INTEGERP (XCAR (watch_descriptor))
         && INTEGERP (XCDR (watch_descriptor))))
    report_file_notify_error ("Invalid descriptor ", watch_descriptor);

  descriptor = XCAR (watch_descriptor);
  id = XCDR (watch_descriptor);
  remove_watch_descriptor (descriptor, id);

  if (NILP (Fassoc (descriptor, watch_list)))
    {
      int wd = XINT (descriptor);
      if (inotify_rm_watch (inotifyfd, wd) == -1)
        report_file_notify_error ("Could not rm watch", watch_descriptor);
    }

  /* Cleanup if no more files are watched.  */
  if (NILP (watch_list))
    {
      emacs_close (inotifyfd);
      delete_read_fd (inotifyfd);
      inotifyfd = -1;
    }

  return Qt;
}

DEFUN ("inotify-valid-p", Finotify_valid_p, Sinotify_valid_p, 1, 1, 0,
       doc: /* Check a watch specified by its WATCH-DESCRIPTOR.

WATCH-DESCRIPTOR should be an object returned by `inotify-add-watch'.

A watch can become invalid if the file or directory it watches is
deleted, or if the watcher thread exits abnormally for any other
reason.  Removing the watch by calling `inotify-rm-watch' also makes
it invalid.  */)
     (Lisp_Object watch_descriptor)
{
  Lisp_Object watches;

  if (! (CONSP (watch_descriptor)
         && INTEGERP (XCAR (watch_descriptor))
         && INTEGERP (XCDR (watch_descriptor))))
    return Qnil;

  watches = Fassoc (XCAR (watch_descriptor), watch_list);

  if (! CONSP (watches))
    return Qnil;
  return CONSP (Fassoc (XCDR (watch_descriptor), XCDR (watches)));
}

#ifdef DEBUG
DEFUN ("inotify-watch-list", Finotify_watch_list, Sinotify_watch_list, 0, 0, 0,
       doc: /* Return a copy of the internal watch_list. */)
{
  return Fcopy_sequence (watch_list);
}

DEFUN ("inotify-allocated-p", Finotify_allocated_p, Sinotify_allocated_p, 0, 0, 0,
       doc: /* Return non-nil, if a inotify instance is allocated. */)
{
  return inotifyfd < 0 ? Qnil : Qt;
}
#endif

void
syms_of_inotify (void)
{
  DEFSYM (Qaccess, "access");		/* IN_ACCESS */
  DEFSYM (Qattrib, "attrib");		/* IN_ATTRIB */
  DEFSYM (Qclose_write, "close-write");	/* IN_CLOSE_WRITE */
  DEFSYM (Qclose_nowrite, "close-nowrite");
					/* IN_CLOSE_NOWRITE */
  DEFSYM (Qcreate, "create");		/* IN_CREATE */
  DEFSYM (Qdelete, "delete");		/* IN_DELETE */
  DEFSYM (Qdelete_self, "delete-self");	/* IN_DELETE_SELF */
  DEFSYM (Qmodify, "modify");		/* IN_MODIFY */
  DEFSYM (Qmove_self, "move-self");	/* IN_MOVE_SELF */
  DEFSYM (Qmoved_from, "moved-from");	/* IN_MOVED_FROM */
  DEFSYM (Qmoved_to, "moved-to");	/* IN_MOVED_TO */
  DEFSYM (Qopen, "open");		/* IN_OPEN */

  DEFSYM (Qall_events, "all-events");	/* IN_ALL_EVENTS */
  DEFSYM (Qmove, "move");		/* IN_MOVE */
  DEFSYM (Qclose, "close");		/* IN_CLOSE */

  DEFSYM (Qdont_follow, "dont-follow");	/* IN_DONT_FOLLOW */
  DEFSYM (Qexcl_unlink, "excl-unlink");	/* IN_EXCL_UNLINK */
  DEFSYM (Qmask_add, "mask-add");	/* IN_MASK_ADD */
  DEFSYM (Qoneshot, "oneshot");		/* IN_ONESHOT */
  DEFSYM (Qonlydir, "onlydir");		/* IN_ONLYDIR */

  DEFSYM (Qignored, "ignored");		/* IN_IGNORED */
  DEFSYM (Qisdir, "isdir");		/* IN_ISDIR */
  DEFSYM (Qq_overflow, "q-overflow");	/* IN_Q_OVERFLOW */
  DEFSYM (Qunmount, "unmount");		/* IN_UNMOUNT */

  defsubr (&Sinotify_add_watch);
  defsubr (&Sinotify_rm_watch);
  defsubr (&Sinotify_valid_p);

#ifdef DEBUG
  defsubr (&Sinotify_watch_list);
  defsubr (&Sinotify_allocated_p);
#endif
  staticpro (&watch_list);

  Fprovide (intern_c_string ("inotify"), Qnil);
}

#endif /* HAVE_INOTIFY */

debug log:

solving 302f52225e ...
found 302f52225e in https://yhetil.org/emacs-bugs/8737e8excq.fsf@luca/
found 61ef615328 in https://git.savannah.gnu.org/cgit/emacs.git
preparing index
index prepared:
100644 61ef6153286e87113fc54d2b4640f01287cb967e	src/inotify.c

applying [1/1] https://yhetil.org/emacs-bugs/8737e8excq.fsf@luca/
diff --git a/src/inotify.c b/src/inotify.c
index 61ef615328..302f52225e 100644

Checking patch src/inotify.c...
Applied patch src/inotify.c cleanly.

index at:
100644 302f52225ef56ad4b7641e01244c09f9dca456d3	src/inotify.c

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).