gio/gfilemonitor.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Alexander Larsson <alexl@redhat.com>
  21  */
  22
  23 #include "config.h"
  24 #include <string.h>
  25
  26 #include "gfilemonitor.h"
  27 #include "gioenumtypes.h"
  28 #include "gfile.h"
  29 #include "gvfs.h"
  30 #include "glibintl.h"
  31
  32
  33 struct _FileChange;
  34 typedef struct _FileChange FileChange;
  35 static void file_change_free (FileChange *change);
  36
  37 /**
  38  * SECTION:gfilemonitor
  39  * @short_description: File Monitor
  40  * @include: gio/gio.h
  41  *
  42  * Monitors a file or directory for changes.
  43  *
  44  * To obtain a #GFileMonitor for a file or directory, use
  45  * g_file_monitor(), g_file_monitor_file(), or
  46  * g_file_monitor_directory().
  47  *
  48  * To get informed about changes to the file or directory you are
  49  * monitoring, connect to the #GFileMonitor::changed signal. The
  50  * signal will be emitted in the <link
  51  * linkend="g-main-context-push-thread-default">thread-default main
  52  * context</link> of the thread that the monitor was created in
  53  * (though if the global default main context is blocked, this may
  54  * cause notifications to be blocked even if the thread-default
  55  * context is still running).
  56  **/
  57
  58 G_LOCK_DEFINE_STATIC(cancelled);
  59
  60 enum {
  61   CHANGED,
  62   LAST_SIGNAL
  63 };
  64
  65 /* work around a limitation of the aliasing foo */
  66 #undef g_file_monitor
  67
  68 G_DEFINE_ABSTRACT_TYPE (GFileMonitor, g_file_monitor, G_TYPE_OBJECT);
  69
  70 typedef struct {
  71   GFile *file;
  72   guint32 last_sent_change_time; /* 0 == not sent */
  73   guint32 send_delayed_change_at; /* 0 == never */
  74   guint32 send_virtual_changes_done_at; /* 0 == never */
  75 } RateLimiter;
  76
  77 struct _GFileMonitorPrivate {
  78   gboolean cancelled;
  79   int rate_limit_msec;
  80
  81   /* Rate limiting change events */
  82   GHashTable *rate_limiter;
  83
  84   GSource *pending_file_change_source;
  85   GSList *pending_file_changes; /* FileChange */
  86
  87   GSource *timeout;
  88   guint32 timeout_fires_at;
  89
  90   GMainContext *context;
  91 };
  92
  93 enum {
  94   PROP_0,
  95   PROP_RATE_LIMIT,
  96   PROP_CANCELLED
  97 };
  98
  99 static void
 100 g_file_monitor_set_property (GObject      *object,
 101                              guint         prop_id,
 102                              const GValue *value,
 103                              GParamSpec   *pspec)
 104 {
 105   GFileMonitor *monitor;
 106
 107   monitor = G_FILE_MONITOR (object);
 108
 109   switch (prop_id)
 110     {
 111     case PROP_RATE_LIMIT:
 112       g_file_monitor_set_rate_limit (monitor, g_value_get_int (value));
 113       break;
 114
 115     default:
 116       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 117       break;
 118     }
 119 }
 120
 121 static void
 122 g_file_monitor_get_property (GObject    *object,
 123                              guint       prop_id,
 124                              GValue     *value,
 125                              GParamSpec *pspec)
 126 {
 127   GFileMonitor *monitor;
 128   GFileMonitorPrivate *priv;
 129
 130   monitor = G_FILE_MONITOR (object);
 131   priv = monitor->priv;
 132
 133   switch (prop_id)
 134     {
 135     case PROP_RATE_LIMIT:
 136       g_value_set_int (value, priv->rate_limit_msec);
 137       break;
 138
 139     case PROP_CANCELLED:
 140       G_LOCK (cancelled);
 141       g_value_set_boolean (value, priv->cancelled);
 142       G_UNLOCK (cancelled);
 143       break;
 144
 145     default:
 146       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 147       break;
 148     }
 149 }
 150
 151 #define DEFAULT_RATE_LIMIT_MSECS 800
 152 #define DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS 2
 153
 154 static guint signals[LAST_SIGNAL] = { 0 };
 155
 156 static void
 157 rate_limiter_free (RateLimiter *limiter)
 158 {
 159   g_object_unref (limiter->file);
 160   g_slice_free (RateLimiter, limiter);
 161 }
 162
 163 static void
 164 g_file_monitor_finalize (GObject *object)
 165 {
 166   GFileMonitor *monitor;
 167
 168   monitor = G_FILE_MONITOR (object);
 169
 170   if (monitor->priv->timeout)
 171     {
 172       g_source_destroy (monitor->priv->timeout);
 173       g_source_unref (monitor->priv->timeout);
 174     }
 175
 176   g_hash_table_destroy (monitor->priv->rate_limiter);
 177
 178   g_main_context_unref (monitor->priv->context);
 179
 180   G_OBJECT_CLASS (g_file_monitor_parent_class)->finalize (object);
 181 }
 182
 183 static void
 184 g_file_monitor_dispose (GObject *object)
 185 {
 186   GFileMonitor *monitor;
 187   GFileMonitorPrivate *priv;
 188
 189   monitor = G_FILE_MONITOR (object);
 190   priv = monitor->priv;
 191
 192   if (priv->pending_file_change_source)
 193     {
 194       g_source_destroy (priv->pending_file_change_source);
 195       g_source_unref (priv->pending_file_change_source);
 196       priv->pending_file_change_source = NULL;
 197     }
 198   g_slist_foreach (priv->pending_file_changes, (GFunc) file_change_free, NULL);
 199   g_slist_free (priv->pending_file_changes);
 200   priv->pending_file_changes = NULL;
 201
 202   /* Make sure we cancel on last unref */
 203   g_file_monitor_cancel (monitor);
 204
 205   G_OBJECT_CLASS (g_file_monitor_parent_class)->dispose (object);
 206 }
 207
 208 static void
 209 g_file_monitor_class_init (GFileMonitorClass *klass)
 210 {
 211   GObjectClass *object_class;
 212
 213   g_type_class_add_private (klass, sizeof (GFileMonitorPrivate));
 214
 215   object_class = G_OBJECT_CLASS (klass);
 216   object_class->finalize = g_file_monitor_finalize;
 217   object_class->dispose = g_file_monitor_dispose;
 218   object_class->get_property = g_file_monitor_get_property;
 219   object_class->set_property = g_file_monitor_set_property;
 220
 221   /**
 222    * GFileMonitor::changed:
 223    * @monitor: a #GFileMonitor.
 224    * @file: a #GFile.
 225    * @other_file: a #GFile or #NULL.
 226    * @event_type: a #GFileMonitorEvent.
 227    *
 228    * Emitted when @file has been changed.
 229    *
 230    * If using #G_FILE_MONITOR_SEND_MOVED flag and @event_type is
 231    * #G_FILE_MONITOR_SEND_MOVED, @file will be set to a #GFile containing the
 232    * old path, and @other_file will be set to a #GFile containing the new path.
 233    *
 234    * In all the other cases, @other_file will be set to #NULL.
 235    **/
 236   signals[CHANGED] =
 237     g_signal_new (I_("changed"),
 238                   G_TYPE_FILE_MONITOR,
 239                   G_SIGNAL_RUN_LAST,
 240                   G_STRUCT_OFFSET (GFileMonitorClass, changed),
 241                   NULL, NULL,
 242                   NULL,
 243                   G_TYPE_NONE, 3,
 244                   G_TYPE_FILE, G_TYPE_FILE, G_TYPE_FILE_MONITOR_EVENT);
 245
 246   g_object_class_install_property (object_class,
 247                                    PROP_RATE_LIMIT,
 248                                    g_param_spec_int ("rate-limit",
 249                                                      P_("Rate limit"),
 250                                                      P_("The limit of the monitor to watch for changes, in milliseconds"),
 251                                                      0, G_MAXINT,
 252                                                      DEFAULT_RATE_LIMIT_MSECS,
 253                                                      G_PARAM_READWRITE|
 254                                                      G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 255
 256   g_object_class_install_property (object_class,
 257                                    PROP_CANCELLED,
 258                                    g_param_spec_boolean ("cancelled",
 259                                                          P_("Cancelled"),
 260                                                          P_("Whether the monitor has been cancelled"),
 261                                                          FALSE,
 262                                                          G_PARAM_READABLE|
 263                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 264 }
 265
 266 static void
 267 g_file_monitor_init (GFileMonitor *monitor)
 268 {
 269   monitor->priv = G_TYPE_INSTANCE_GET_PRIVATE (monitor,
 270                                                G_TYPE_FILE_MONITOR,
 271                                                GFileMonitorPrivate);
 272   monitor->priv->rate_limit_msec = DEFAULT_RATE_LIMIT_MSECS;
 273   monitor->priv->rate_limiter = g_hash_table_new_full (g_file_hash, (GEqualFunc)g_file_equal,
 274                                                        NULL, (GDestroyNotify) rate_limiter_free);
 275   monitor->priv->context = g_main_context_ref_thread_default ();
 276 }
 277
 278 /**
 279  * g_file_monitor_is_cancelled:
 280  * @monitor: a #GFileMonitor
 281  *
 282  * Returns whether the monitor is canceled.
 283  *
 284  * Returns: %TRUE if monitor is canceled. %FALSE otherwise.
 285  **/
 286 gboolean
 287 g_file_monitor_is_cancelled (GFileMonitor *monitor)
 288 {
 289   gboolean res;
 290
 291   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 292
 293   G_LOCK (cancelled);
 294   res = monitor->priv->cancelled;
 295   G_UNLOCK (cancelled);
 296
 297   return res;
 298 }
 299
 300 /**
 301  * g_file_monitor_cancel:
 302  * @monitor: a #GFileMonitor.
 303  *
 304  * Cancels a file monitor.
 305  *
 306  * Returns: %TRUE if monitor was cancelled.
 307  **/
 308 gboolean
 309 g_file_monitor_cancel (GFileMonitor* monitor)
 310 {
 311   GFileMonitorClass *klass;
 312
 313   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 314
 315   G_LOCK (cancelled);
 316   if (monitor->priv->cancelled)
 317     {
 318       G_UNLOCK (cancelled);
 319       return TRUE;
 320     }
 321
 322   monitor->priv->cancelled = TRUE;
 323   G_UNLOCK (cancelled);
 324
 325   g_object_notify (G_OBJECT (monitor), "cancelled");
 326
 327   klass = G_FILE_MONITOR_GET_CLASS (monitor);
 328   return (* klass->cancel) (monitor);
 329 }
 330
 331 /**
 332  * g_file_monitor_set_rate_limit:
 333  * @monitor: a #GFileMonitor.
 334  * @limit_msecs: a non-negative integer with the limit in milliseconds
 335  *     to poll for changes
 336  *
 337  * Sets the rate limit to which the @monitor will report
 338  * consecutive change events to the same file.
 339  */
 340 void
 341 g_file_monitor_set_rate_limit (GFileMonitor *monitor,
 342                                gint          limit_msecs)
 343 {
 344   GFileMonitorPrivate *priv;
 345
 346   g_return_if_fail (G_IS_FILE_MONITOR (monitor));
 347   g_return_if_fail (limit_msecs >= 0);
 348
 349   priv = monitor->priv;
 350   if (priv->rate_limit_msec != limit_msecs)
 351     {
 352       monitor->priv->rate_limit_msec = limit_msecs;
 353       g_object_notify (G_OBJECT (monitor), "rate-limit");
 354     }
 355 }
 356
 357 struct _FileChange {
 358   GFile             *child;
 359   GFile             *other_file;
 360   GFileMonitorEvent  event_type;
 361 };
 362
 363 static void
 364 file_change_free (FileChange *change)
 365 {
 366   g_object_unref (change->child);
 367   if (change->other_file)
 368     g_object_unref (change->other_file);
 369
 370   g_slice_free (FileChange, change);
 371 }
 372
 373 static gboolean
 374 emit_cb (gpointer data)
 375 {
 376   GFileMonitor *monitor = G_FILE_MONITOR (data);
 377   GSList *pending, *iter;
 378
 379   pending = g_slist_reverse (monitor->priv->pending_file_changes);
 380   monitor->priv->pending_file_changes = NULL;
 381   if (monitor->priv->pending_file_change_source)
 382     {
 383       g_source_unref (monitor->priv->pending_file_change_source);
 384       monitor->priv->pending_file_change_source = NULL;
 385     }
 386
 387   g_object_ref (monitor);
 388   for (iter = pending; iter; iter = iter->next)
 389     {
 390        FileChange *change = iter->data;
 391        g_signal_emit (monitor, signals[CHANGED], 0,
 392                       change->child, change->other_file, change->event_type);
 393        file_change_free (change);
 394     }
 395   g_slist_free (pending);
 396   g_object_unref (monitor);
 397
 398   return FALSE;
 399 }
 400
 401 static void
 402 emit_in_idle (GFileMonitor      *monitor,
 403               GFile             *child,
 404               GFile             *other_file,
 405               GFileMonitorEvent  event_type)
 406 {
 407   GSource *source;
 408   FileChange *change;
 409   GFileMonitorPrivate *priv;
 410
 411   priv = monitor->priv;
 412
 413   change = g_slice_new (FileChange);
 414
 415   change->child = g_object_ref (child);
 416   if (other_file)
 417     change->other_file = g_object_ref (other_file);
 418   else
 419     change->other_file = NULL;
 420   change->event_type = event_type;
 421
 422   if (!priv->pending_file_change_source)
 423     {
 424       source = g_idle_source_new ();
 425       priv->pending_file_change_source = source;
 426       g_source_set_priority (source, 0);
 427
 428       /* We don't ref monitor here - instead dispose will free any
 429        * pending idles.
 430        */
 431       g_source_set_callback (source, emit_cb, monitor, NULL);
 432       g_source_attach (source, monitor->priv->context);
 433     }
 434   /* We reverse this in the processor */
 435   priv->pending_file_changes = g_slist_prepend (priv->pending_file_changes, change);
 436 }
 437
 438 static guint32
 439 get_time_msecs (void)
 440 {
 441   return g_get_monotonic_time () / G_TIME_SPAN_MILLISECOND;
 442 }
 443
 444 static guint32
 445 time_difference (guint32 from, guint32 to)
 446 {
 447   if (from > to)
 448     return 0;
 449   return to - from;
 450 }
 451
 452 /* Change event rate limiting support: */
 453
 454 static RateLimiter *
 455 new_limiter (GFileMonitor *monitor,
 456              GFile             *file)
 457 {
 458   RateLimiter *limiter;
 459
 460   limiter = g_slice_new0 (RateLimiter);
 461   limiter->file = g_object_ref (file);
 462   g_hash_table_insert (monitor->priv->rate_limiter, file, limiter);
 463
 464   return limiter;
 465 }
 466
 467 static void
 468 rate_limiter_send_virtual_changes_done_now (GFileMonitor *monitor,
 469                                             RateLimiter  *limiter)
 470 {
 471   if (limiter->send_virtual_changes_done_at != 0)
 472     {
 473       emit_in_idle (monitor, limiter->file, NULL,
 474                     G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT);
 475       limiter->send_virtual_changes_done_at = 0;
 476     }
 477 }
 478
 479 static void
 480 rate_limiter_send_delayed_change_now (GFileMonitor *monitor,
 481                                       RateLimiter *limiter,
 482                                       guint32 time_now)
 483 {
 484   if (limiter->send_delayed_change_at != 0)
 485     {
 486       emit_in_idle (monitor,
 487                     limiter->file, NULL,
 488                     G_FILE_MONITOR_EVENT_CHANGED);
 489       limiter->send_delayed_change_at = 0;
 490       limiter->last_sent_change_time = time_now;
 491     }
 492 }
 493
 494 typedef struct {
 495   guint32 min_time;
 496   guint32 time_now;
 497   GFileMonitor *monitor;
 498 } ForEachData;
 499
 500 static gboolean
 501 calc_min_time (GFileMonitor *monitor,
 502                RateLimiter *limiter,
 503                guint32 time_now,
 504                guint32 *min_time)
 505 {
 506   gboolean delete_me;
 507   guint32 expire_at;
 508
 509   delete_me = TRUE;
 510
 511   if (limiter->last_sent_change_time != 0)
 512     {
 513       /* Set a timeout at 2*rate limit so that we can clear out the change from the hash eventually */
 514       expire_at = limiter->last_sent_change_time + 2 * monitor->priv->rate_limit_msec;
 515
 516       if (time_difference (time_now, expire_at) > 0)
 517         {
 518           delete_me = FALSE;
 519           *min_time = MIN (*min_time,
 520                            time_difference (time_now, expire_at));
 521         }
 522     }
 523
 524   if (limiter->send_delayed_change_at != 0)
 525     {
 526       delete_me = FALSE;
 527       *min_time = MIN (*min_time,
 528                        time_difference (time_now, limiter->send_delayed_change_at));
 529     }
 530
 531   if (limiter->send_virtual_changes_done_at != 0)
 532     {
 533       delete_me = FALSE;
 534       *min_time = MIN (*min_time,
 535                        time_difference (time_now, limiter->send_virtual_changes_done_at));
 536     }
 537
 538   return delete_me;
 539 }
 540
 541 static gboolean
 542 foreach_rate_limiter_fire (gpointer key,
 543                            gpointer value,
 544                            gpointer user_data)
 545 {
 546   RateLimiter *limiter = value;
 547   ForEachData *data = user_data;
 548
 549   if (limiter->send_delayed_change_at != 0 &&
 550       time_difference (data->time_now, limiter->send_delayed_change_at) == 0)
 551     rate_limiter_send_delayed_change_now (data->monitor, limiter, data->time_now);
 552
 553   if (limiter->send_virtual_changes_done_at != 0 &&
 554       time_difference (data->time_now, limiter->send_virtual_changes_done_at) == 0)
 555     rate_limiter_send_virtual_changes_done_now (data->monitor, limiter);
 556
 557   return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
 558 }
 559
 560 static gboolean
 561 rate_limiter_timeout (gpointer timeout_data)
 562 {
 563   GFileMonitor *monitor = timeout_data;
 564   ForEachData data;
 565   GSource *source;
 566
 567   data.min_time = G_MAXUINT32;
 568   data.monitor = monitor;
 569   data.time_now = get_time_msecs ();
 570   g_hash_table_foreach_remove (monitor->priv->rate_limiter,
 571                                foreach_rate_limiter_fire,
 572                                &data);
 573
 574   /* Remove old timeout */
 575   if (monitor->priv->timeout)
 576     {
 577       g_source_destroy (monitor->priv->timeout);
 578       g_source_unref (monitor->priv->timeout);
 579       monitor->priv->timeout = NULL;
 580       monitor->priv->timeout_fires_at = 0;
 581     }
 582
 583   /* Set up new timeout */
 584   if (data.min_time != G_MAXUINT32)
 585     {
 586       source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
 587       g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
 588       g_source_attach (source, monitor->priv->context);
 589
 590       monitor->priv->timeout = source;
 591       monitor->priv->timeout_fires_at = data.time_now + data.min_time;
 592     }
 593
 594   return FALSE;
 595 }
 596
 597 static gboolean
 598 foreach_rate_limiter_update (gpointer key,
 599                              gpointer value,
 600                              gpointer user_data)
 601 {
 602   RateLimiter *limiter = value;
 603   ForEachData *data = user_data;
 604
 605   return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
 606 }
 607
 608 static void
 609 update_rate_limiter_timeout (GFileMonitor *monitor,
 610                              guint new_time)
 611 {
 612   ForEachData data;
 613   GSource *source;
 614
 615   if (monitor->priv->timeout_fires_at != 0 && new_time != 0 &&
 616       time_difference (new_time, monitor->priv->timeout_fires_at) == 0)
 617     return; /* Nothing to do, we already fire earlier than that */
 618
 619   data.min_time = G_MAXUINT32;
 620   data.monitor = monitor;
 621   data.time_now = get_time_msecs ();
 622   g_hash_table_foreach_remove (monitor->priv->rate_limiter,
 623                                foreach_rate_limiter_update,
 624                                &data);
 625
 626   /* Remove old timeout */
 627   if (monitor->priv->timeout)
 628     {
 629       g_source_destroy (monitor->priv->timeout);
 630       g_source_unref (monitor->priv->timeout);
 631       monitor->priv->timeout_fires_at = 0;
 632       monitor->priv->timeout = NULL;
 633     }
 634
 635   /* Set up new timeout */
 636   if (data.min_time != G_MAXUINT32)
 637     {
 638       source = g_timeout_source_new (data.min_time + 1);  /* + 1 to make sure we've really passed the time */
 639       g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
 640       g_source_attach (source, monitor->priv->context);
 641
 642       monitor->priv->timeout = source;
 643       monitor->priv->timeout_fires_at = data.time_now + data.min_time;
 644     }
 645 }
 646
 647 /**
 648  * g_file_monitor_emit_event:
 649  * @monitor: a #GFileMonitor.
 650  * @child: a #GFile.
 651  * @other_file: a #GFile.
 652  * @event_type: a set of #GFileMonitorEvent flags.
 653  *
 654  * Emits the #GFileMonitor::changed signal if a change
 655  * has taken place. Should be called from file monitor
 656  * implementations only.
 657  *
 658  * The signal will be emitted from an idle handler (in the <link
 659  * linkend="g-main-context-push-thread-default">thread-default main
 660  * context</link>).
 661  **/
 662 void
 663 g_file_monitor_emit_event (GFileMonitor      *monitor,
 664                            GFile             *child,
 665                            GFile             *other_file,
 666                            GFileMonitorEvent  event_type)
 667 {
 668   guint32 time_now, since_last;
 669   gboolean emit_now;
 670   RateLimiter *limiter;
 671
 672   g_return_if_fail (G_IS_FILE_MONITOR (monitor));
 673   g_return_if_fail (G_IS_FILE (child));
 674
 675   limiter = g_hash_table_lookup (monitor->priv->rate_limiter, child);
 676
 677   if (event_type != G_FILE_MONITOR_EVENT_CHANGED)
 678     {
 679       if (limiter)
 680         {
 681           rate_limiter_send_delayed_change_now (monitor, limiter, get_time_msecs ());
 682           if (event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT)
 683             limiter->send_virtual_changes_done_at = 0;
 684           else
 685             rate_limiter_send_virtual_changes_done_now (monitor, limiter);
 686           update_rate_limiter_timeout (monitor, 0);
 687         }
 688       emit_in_idle (monitor, child, other_file, event_type);
 689     }
 690   else
 691     {
 692       /* Changed event, rate limit */
 693       time_now = get_time_msecs ();
 694       emit_now = TRUE;
 695
 696       if (limiter)
 697         {
 698           since_last = time_difference (limiter->last_sent_change_time, time_now);
 699           if (since_last < monitor->priv->rate_limit_msec)
 700             {
 701               /* We ignore this change, but arm a timer so that we can fire it later if we
 702                  don't get any other events (that kill this timeout) */
 703               emit_now = FALSE;
 704               if (limiter->send_delayed_change_at == 0)
 705                 {
 706                   limiter->send_delayed_change_at = time_now + monitor->priv->rate_limit_msec;
 707                   update_rate_limiter_timeout (monitor, limiter->send_delayed_change_at);
 708                 }
 709             }
 710         }
 711
 712       if (limiter == NULL)
 713         limiter = new_limiter (monitor, child);
 714
 715       if (emit_now)
 716         {
 717           emit_in_idle (monitor, child, other_file, event_type);
 718
 719           limiter->last_sent_change_time = time_now;
 720           limiter->send_delayed_change_at = 0;
 721           /* Set a timeout of 2*rate limit so that we can clear out the change from the hash eventually */
 722           update_rate_limiter_timeout (monitor, time_now + 2 * monitor->priv->rate_limit_msec);
 723         }
 724
 725       /* Schedule a virtual change done. This is removed if we get a real one, and
 726          postponed if we get more change events. */
 727
 728       limiter->send_virtual_changes_done_at = time_now + DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS * 1000;
 729       update_rate_limiter_timeout (monitor, limiter->send_virtual_changes_done_at);
 730     }
 731 }