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 "gio-marshal.h"
  28 #include "gioenumtypes.h"
  29 #include "gfile.h"
  30 #include "gvfs.h"
  31 #include "glibintl.h"
  32
  33
  34 struct _FileChange;
  35 typedef struct _FileChange FileChange;
  36 static void file_change_free (FileChange *change);
  37
  38 /**
  39  * SECTION:gfilemonitor
  40  * @short_description: File Monitor
  41  * @include: gio/gio.h
  42  *
  43  * Monitors a file or directory for changes.
  44  *
  45  * To obtain a #GFileMonitor for a file or directory, use
  46  * g_file_monitor(), g_file_monitor_file(), or
  47  * g_file_monitor_directory().
  48  *
  49  * To get informed about changes to the file or directory you are
  50  * monitoring, connect to the #GFileMonitor::changed signal. The
  51  * signal will be emitted in the <link
  52  * linkend="g-main-context-push-thread-default">thread-default main
  53  * context</link> of the thread that the monitor was created in
  54  * (though if the global default main context is blocked, this may
  55  * cause notifications to be blocked even if the thread-default
  56  * context is still running).
  57  **/
  58
  59 G_LOCK_DEFINE_STATIC(cancelled);
  60
  61 enum {
  62   CHANGED,
  63   LAST_SIGNAL
  64 };
  65
  66 /* work around a limitation of the aliasing foo */
  67 #undef g_file_monitor
  68
  69 G_DEFINE_ABSTRACT_TYPE (GFileMonitor, g_file_monitor, G_TYPE_OBJECT);
  70
  71 typedef struct {
  72   GFile *file;
  73   guint32 last_sent_change_time; /* 0 == not sent */
  74   guint32 send_delayed_change_at; /* 0 == never */
  75   guint32 send_virtual_changes_done_at; /* 0 == never */
  76 } RateLimiter;
  77
  78 struct _GFileMonitorPrivate {
  79   gboolean cancelled;
  80   int rate_limit_msec;
  81
  82   /* Rate limiting change events */
  83   GHashTable *rate_limiter;
  84
  85   GSource *pending_file_change_source;
  86   GSList *pending_file_changes; /* FileChange */
  87
  88   GSource *timeout;
  89   guint32 timeout_fires_at;
  90
  91   GMainContext *context;
  92 };
  93
  94 enum {
  95   PROP_0,
  96   PROP_RATE_LIMIT,
  97   PROP_CANCELLED
  98 };
  99
 100 static void
 101 g_file_monitor_set_property (GObject      *object,
 102                              guint         prop_id,
 103                              const GValue *value,
 104                              GParamSpec   *pspec)
 105 {
 106   GFileMonitor *monitor;
 107
 108   monitor = G_FILE_MONITOR (object);
 109
 110   switch (prop_id)
 111     {
 112     case PROP_RATE_LIMIT:
 113       g_file_monitor_set_rate_limit (monitor, g_value_get_int (value));
 114       break;
 115
 116     default:
 117       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 118       break;
 119     }
 120 }
 121
 122 static void
 123 g_file_monitor_get_property (GObject    *object,
 124                              guint       prop_id,
 125                              GValue     *value,
 126                              GParamSpec *pspec)
 127 {
 128   GFileMonitor *monitor;
 129   GFileMonitorPrivate *priv;
 130
 131   monitor = G_FILE_MONITOR (object);
 132   priv = monitor->priv;
 133
 134   switch (prop_id)
 135     {
 136     case PROP_RATE_LIMIT:
 137       g_value_set_int (value, priv->rate_limit_msec);
 138       break;
 139
 140     case PROP_CANCELLED:
 141       G_LOCK (cancelled);
 142       g_value_set_boolean (value, priv->cancelled);
 143       G_UNLOCK (cancelled);
 144       break;
 145
 146     default:
 147       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 148       break;
 149     }
 150 }
 151
 152 #define DEFAULT_RATE_LIMIT_MSECS 800
 153 #define DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS 2
 154
 155 static guint signals[LAST_SIGNAL] = { 0 };
 156
 157 static void
 158 rate_limiter_free (RateLimiter *limiter)
 159 {
 160   g_object_unref (limiter->file);
 161   g_slice_free (RateLimiter, limiter);
 162 }
 163
 164 static void
 165 g_file_monitor_finalize (GObject *object)
 166 {
 167   GFileMonitor *monitor;
 168
 169   monitor = G_FILE_MONITOR (object);
 170
 171   if (monitor->priv->timeout)
 172     {
 173       g_source_destroy (monitor->priv->timeout);
 174       g_source_unref (monitor->priv->timeout);
 175     }
 176
 177   g_hash_table_destroy (monitor->priv->rate_limiter);
 178
 179   if (monitor->priv->context)
 180     g_main_context_unref (monitor->priv->context);
 181
 182   G_OBJECT_CLASS (g_file_monitor_parent_class)->finalize (object);
 183 }
 184
 185 static void
 186 g_file_monitor_dispose (GObject *object)
 187 {
 188   GFileMonitor *monitor;
 189   GFileMonitorPrivate *priv;
 190
 191   monitor = G_FILE_MONITOR (object);
 192   priv = monitor->priv;
 193
 194   if (priv->pending_file_change_source)
 195     {
 196       g_source_destroy (priv->pending_file_change_source);
 197       g_source_unref (priv->pending_file_change_source);
 198       priv->pending_file_change_source = NULL;
 199     }
 200   g_slist_foreach (priv->pending_file_changes, (GFunc) file_change_free, NULL);
 201   g_slist_free (priv->pending_file_changes);
 202   priv->pending_file_changes = NULL;
 203
 204   /* Make sure we cancel on last unref */
 205   g_file_monitor_cancel (monitor);
 206
 207   G_OBJECT_CLASS (g_file_monitor_parent_class)->dispose (object);
 208 }
 209
 210 static void
 211 g_file_monitor_class_init (GFileMonitorClass *klass)
 212 {
 213   GObjectClass *object_class;
 214
 215   g_type_class_add_private (klass, sizeof (GFileMonitorPrivate));
 216
 217   object_class = G_OBJECT_CLASS (klass);
 218   object_class->finalize = g_file_monitor_finalize;
 219   object_class->dispose = g_file_monitor_dispose;
 220   object_class->get_property = g_file_monitor_get_property;
 221   object_class->set_property = g_file_monitor_set_property;
 222
 223   /**
 224    * GFileMonitor::changed:
 225    * @monitor: a #GFileMonitor.
 226    * @file: a #GFile.
 227    * @other_file: a #GFile or #NULL.
 228    * @event_type: a #GFileMonitorEvent.
 229    *
 230    * Emitted when @file has been changed.
 231    *
 232    * If using #G_FILE_MONITOR_SEND_MOVED flag and @event_type is
 233    * #G_FILE_MONITOR_SEND_MOVED, @file will be set to a #GFile containing the
 234    * old path, and @other_file will be set to a #GFile containing the new path.
 235    *
 236    * In all the other cases, @other_file will be set to #NULL.
 237    **/
 238   signals[CHANGED] =
 239     g_signal_new (I_("changed"),
 240                   G_TYPE_FILE_MONITOR,
 241                   G_SIGNAL_RUN_LAST,
 242                   G_STRUCT_OFFSET (GFileMonitorClass, changed),
 243                   NULL, NULL,
 244                   _gio_marshal_VOID__OBJECT_OBJECT_ENUM,
 245                   G_TYPE_NONE, 3,
 246                   G_TYPE_FILE, G_TYPE_FILE, G_TYPE_FILE_MONITOR_EVENT);
 247
 248   g_object_class_install_property (object_class,
 249                                    PROP_RATE_LIMIT,
 250                                    g_param_spec_int ("rate-limit",
 251                                                      P_("Rate limit"),
 252                                                      P_("The limit of the monitor to watch for changes, in milliseconds"),
 253                                                      0, G_MAXINT,
 254                                                      DEFAULT_RATE_LIMIT_MSECS,
 255                                                      G_PARAM_READWRITE|
 256                                                      G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 257
 258   g_object_class_install_property (object_class,
 259                                    PROP_CANCELLED,
 260                                    g_param_spec_boolean ("cancelled",
 261                                                          P_("Cancelled"),
 262                                                          P_("Whether the monitor has been cancelled"),
 263                                                          FALSE,
 264                                                          G_PARAM_READABLE|
 265                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 266 }
 267
 268 static void
 269 g_file_monitor_init (GFileMonitor *monitor)
 270 {
 271   monitor->priv = G_TYPE_INSTANCE_GET_PRIVATE (monitor,
 272                                                G_TYPE_FILE_MONITOR,
 273                                                GFileMonitorPrivate);
 274   monitor->priv->rate_limit_msec = DEFAULT_RATE_LIMIT_MSECS;
 275   monitor->priv->rate_limiter = g_hash_table_new_full (g_file_hash, (GEqualFunc)g_file_equal,
 276                                                        NULL, (GDestroyNotify) rate_limiter_free);
 277   monitor->priv->context = g_main_context_get_thread_default ();
 278 }
 279
 280 /**
 281  * g_file_monitor_is_cancelled:
 282  * @monitor: a #GFileMonitor
 283  *
 284  * Returns whether the monitor is canceled.
 285  *
 286  * Returns: %TRUE if monitor is canceled. %FALSE otherwise.
 287  **/
 288 gboolean
 289 g_file_monitor_is_cancelled (GFileMonitor *monitor)
 290 {
 291   gboolean res;
 292
 293   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 294
 295   G_LOCK (cancelled);
 296   res = monitor->priv->cancelled;
 297   G_UNLOCK (cancelled);
 298
 299   return res;
 300 }
 301
 302 /**
 303  * g_file_monitor_cancel:
 304  * @monitor: a #GFileMonitor.
 305  *
 306  * Cancels a file monitor.
 307  *
 308  * Returns: %TRUE if monitor was cancelled.
 309  **/
 310 gboolean
 311 g_file_monitor_cancel (GFileMonitor* monitor)
 312 {
 313   GFileMonitorClass *klass;
 314
 315   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 316
 317   G_LOCK (cancelled);
 318   if (monitor->priv->cancelled)
 319     {
 320       G_UNLOCK (cancelled);
 321       return TRUE;
 322     }
 323
 324   monitor->priv->cancelled = TRUE;
 325   G_UNLOCK (cancelled);
 326
 327   g_object_notify (G_OBJECT (monitor), "cancelled");
 328
 329   klass = G_FILE_MONITOR_GET_CLASS (monitor);
 330   return (* klass->cancel) (monitor);
 331 }
 332
 333 /**
 334  * g_file_monitor_set_rate_limit:
 335  * @monitor: a #GFileMonitor.
 336  * @limit_msecs: a non-negative integer with the limit in milliseconds
 337  *     to poll for changes
 338  *
 339  * Sets the rate limit to which the @monitor will report
 340  * consecutive change events to the same file.
 341  */
 342 void
 343 g_file_monitor_set_rate_limit (GFileMonitor *monitor,
 344                                gint          limit_msecs)
 345 {
 346   GFileMonitorPrivate *priv;
 347
 348   g_return_if_fail (G_IS_FILE_MONITOR (monitor));
 349   g_return_if_fail (limit_msecs >= 0);
 350
 351   priv = monitor->priv;
 352   if (priv->rate_limit_msec != limit_msecs)
 353     {
 354       monitor->priv->rate_limit_msec = limit_msecs;
 355       g_object_notify (G_OBJECT (monitor), "rate-limit");
 356     }
 357 }
 358
 359 struct _FileChange {
 360   GFile             *child;
 361   GFile             *other_file;
 362   GFileMonitorEvent  event_type;
 363 };
 364
 365 static void
 366 file_change_free (FileChange *change)
 367 {
 368   g_object_unref (change->child);
 369   if (change->other_file)
 370     g_object_unref (change->other_file);
 371
 372   g_slice_free (FileChange, change);
 373 }
 374
 375 static gboolean
 376 emit_cb (gpointer data)
 377 {
 378   GFileMonitor *monitor = G_FILE_MONITOR (data);
 379   GSList *pending, *iter;
 380
 381   pending = g_slist_reverse (monitor->priv->pending_file_changes);
 382   monitor->priv->pending_file_changes = NULL;
 383   if (monitor->priv->pending_file_change_source)
 384     {
 385       g_source_unref (monitor->priv->pending_file_change_source);
 386       monitor->priv->pending_file_change_source = NULL;
 387     }
 388
 389   g_object_ref (monitor);
 390   for (iter = pending; iter; iter = iter->next)
 391     {
 392        FileChange *change = iter->data;
 393        g_signal_emit (monitor, signals[CHANGED], 0,
 394                       change->child, change->other_file, change->event_type);
 395        file_change_free (change);
 396     }
 397   g_slist_free (pending);
 398   g_object_unref (monitor);
 399
 400   return FALSE;
 401 }
 402
 403 static void
 404 emit_in_idle (GFileMonitor      *monitor,
 405               GFile             *child,
 406               GFile             *other_file,
 407               GFileMonitorEvent  event_type)
 408 {
 409   GSource *source;
 410   FileChange *change;
 411   GFileMonitorPrivate *priv;
 412
 413   priv = monitor->priv;
 414
 415   change = g_slice_new (FileChange);
 416
 417   change->child = g_object_ref (child);
 418   if (other_file)
 419     change->other_file = g_object_ref (other_file);
 420   else
 421     change->other_file = NULL;
 422   change->event_type = event_type;
 423
 424   if (!priv->pending_file_change_source)
 425     {
 426       source = g_idle_source_new ();
 427       priv->pending_file_change_source = source;
 428       g_source_set_priority (source, 0);
 429
 430       /* We don't ref monitor here - instead dispose will free any
 431        * pending idles.
 432        */
 433       g_source_set_callback (source, emit_cb, monitor, NULL);
 434       g_source_attach (source, monitor->priv->context);
 435     }
 436   /* We reverse this in the processor */
 437   priv->pending_file_changes = g_slist_prepend (priv->pending_file_changes, change);
 438 }
 439
 440 static guint32
 441 get_time_msecs (void)
 442 {
 443   return g_thread_gettime() / (1000 * 1000);
 444 }
 445
 446 static guint32
 447 time_difference (guint32 from, guint32 to)
 448 {
 449   if (from > to)
 450     return 0;
 451   return to - from;
 452 }
 453
 454 /* Change event rate limiting support: */
 455
 456 static RateLimiter *
 457 new_limiter (GFileMonitor *monitor,
 458              GFile             *file)
 459 {
 460   RateLimiter *limiter;
 461
 462   limiter = g_slice_new0 (RateLimiter);
 463   limiter->file = g_object_ref (file);
 464   g_hash_table_insert (monitor->priv->rate_limiter, file, limiter);
 465
 466   return limiter;
 467 }
 468
 469 static void
 470 rate_limiter_send_virtual_changes_done_now (GFileMonitor *monitor,
 471                                             RateLimiter  *limiter)
 472 {
 473   if (limiter->send_virtual_changes_done_at != 0)
 474     {
 475       emit_in_idle (monitor, limiter->file, NULL,
 476                     G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT);
 477       limiter->send_virtual_changes_done_at = 0;
 478     }
 479 }
 480
 481 static void
 482 rate_limiter_send_delayed_change_now (GFileMonitor *monitor,
 483                                       RateLimiter *limiter,
 484                                       guint32 time_now)
 485 {
 486   if (limiter->send_delayed_change_at != 0)
 487     {
 488       emit_in_idle (monitor,
 489                     limiter->file, NULL,
 490                     G_FILE_MONITOR_EVENT_CHANGED);
 491       limiter->send_delayed_change_at = 0;
 492       limiter->last_sent_change_time = time_now;
 493     }
 494 }
 495
 496 typedef struct {
 497   guint32 min_time;
 498   guint32 time_now;
 499   GFileMonitor *monitor;
 500 } ForEachData;
 501
 502 static gboolean
 503 calc_min_time (GFileMonitor *monitor,
 504                RateLimiter *limiter,
 505                guint32 time_now,
 506                guint32 *min_time)
 507 {
 508   gboolean delete_me;
 509   guint32 expire_at;
 510
 511   delete_me = TRUE;
 512
 513   if (limiter->last_sent_change_time != 0)
 514     {
 515       /* Set a timeout at 2*rate limit so that we can clear out the change from the hash eventualy */
 516       expire_at = limiter->last_sent_change_time + 2 * monitor->priv->rate_limit_msec;
 517
 518       if (time_difference (time_now, expire_at) > 0)
 519         {
 520           delete_me = FALSE;
 521           *min_time = MIN (*min_time,
 522                            time_difference (time_now, expire_at));
 523         }
 524     }
 525
 526   if (limiter->send_delayed_change_at != 0)
 527     {
 528       delete_me = FALSE;
 529       *min_time = MIN (*min_time,
 530                        time_difference (time_now, limiter->send_delayed_change_at));
 531     }
 532
 533   if (limiter->send_virtual_changes_done_at != 0)
 534     {
 535       delete_me = FALSE;
 536       *min_time = MIN (*min_time,
 537                        time_difference (time_now, limiter->send_virtual_changes_done_at));
 538     }
 539
 540   return delete_me;
 541 }
 542
 543 static gboolean
 544 foreach_rate_limiter_fire (gpointer key,
 545                            gpointer value,
 546                            gpointer user_data)
 547 {
 548   RateLimiter *limiter = value;
 549   ForEachData *data = user_data;
 550
 551   if (limiter->send_delayed_change_at != 0 &&
 552       time_difference (data->time_now, limiter->send_delayed_change_at) == 0)
 553     rate_limiter_send_delayed_change_now (data->monitor, limiter, data->time_now);
 554
 555   if (limiter->send_virtual_changes_done_at != 0 &&
 556       time_difference (data->time_now, limiter->send_virtual_changes_done_at) == 0)
 557     rate_limiter_send_virtual_changes_done_now (data->monitor, limiter);
 558
 559   return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
 560 }
 561
 562 static gboolean
 563 rate_limiter_timeout (gpointer timeout_data)
 564 {
 565   GFileMonitor *monitor = timeout_data;
 566   ForEachData data;
 567   GSource *source;
 568
 569   data.min_time = G_MAXUINT32;
 570   data.monitor = monitor;
 571   data.time_now = get_time_msecs ();
 572   g_hash_table_foreach_remove (monitor->priv->rate_limiter,
 573                                foreach_rate_limiter_fire,
 574                                &data);
 575
 576   /* Remove old timeout */
 577   if (monitor->priv->timeout)
 578     {
 579       g_source_destroy (monitor->priv->timeout);
 580       g_source_unref (monitor->priv->timeout);
 581       monitor->priv->timeout = NULL;
 582       monitor->priv->timeout_fires_at = 0;
 583     }
 584
 585   /* Set up new timeout */
 586   if (data.min_time != G_MAXUINT32)
 587     {
 588       source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
 589       g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
 590       g_source_attach (source, monitor->priv->context);
 591
 592       monitor->priv->timeout = source;
 593       monitor->priv->timeout_fires_at = data.time_now + data.min_time;
 594     }
 595
 596   return FALSE;
 597 }
 598
 599 static gboolean
 600 foreach_rate_limiter_update (gpointer key,
 601                              gpointer value,
 602                              gpointer user_data)
 603 {
 604   RateLimiter *limiter = value;
 605   ForEachData *data = user_data;
 606
 607   return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
 608 }
 609
 610 static void
 611 update_rate_limiter_timeout (GFileMonitor *monitor,
 612                              guint new_time)
 613 {
 614   ForEachData data;
 615   GSource *source;
 616
 617   if (monitor->priv->timeout_fires_at != 0 && new_time != 0 &&
 618       time_difference (new_time, monitor->priv->timeout_fires_at) == 0)
 619     return; /* Nothing to do, we already fire earlier than that */
 620
 621   data.min_time = G_MAXUINT32;
 622   data.monitor = monitor;
 623   data.time_now = get_time_msecs ();
 624   g_hash_table_foreach_remove (monitor->priv->rate_limiter,
 625                                foreach_rate_limiter_update,
 626                                &data);
 627
 628   /* Remove old timeout */
 629   if (monitor->priv->timeout)
 630     {
 631       g_source_destroy (monitor->priv->timeout);
 632       g_source_unref (monitor->priv->timeout);
 633       monitor->priv->timeout_fires_at = 0;
 634       monitor->priv->timeout = NULL;
 635     }
 636
 637   /* Set up new timeout */
 638   if (data.min_time != G_MAXUINT32)
 639     {
 640       source = g_timeout_source_new (data.min_time + 1);  /* + 1 to make sure we've really passed the time */
 641       g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
 642       g_source_attach (source, monitor->priv->context);
 643
 644       monitor->priv->timeout = source;
 645       monitor->priv->timeout_fires_at = data.time_now + data.min_time;
 646     }
 647 }
 648
 649 /**
 650  * g_file_monitor_emit_event:
 651  * @monitor: a #GFileMonitor.
 652  * @child: a #GFile.
 653  * @other_file: a #GFile.
 654  * @event_type: a set of #GFileMonitorEvent flags.
 655  *
 656  * Emits the #GFileMonitor::changed signal if a change
 657  * has taken place. Should be called from file monitor
 658  * implementations only.
 659  *
 660  * The signal will be emitted from an idle handler (in the <link
 661  * linkend="g-main-context-push-thread-default">thread-default main
 662  * context</link>).
 663  **/
 664 void
 665 g_file_monitor_emit_event (GFileMonitor      *monitor,
 666                            GFile             *child,
 667                            GFile             *other_file,
 668                            GFileMonitorEvent  event_type)
 669 {
 670   guint32 time_now, since_last;
 671   gboolean emit_now;
 672   RateLimiter *limiter;
 673
 674   g_return_if_fail (G_IS_FILE_MONITOR (monitor));
 675   g_return_if_fail (G_IS_FILE (child));
 676
 677   limiter = g_hash_table_lookup (monitor->priv->rate_limiter, child);
 678
 679   if (event_type != G_FILE_MONITOR_EVENT_CHANGED)
 680     {
 681       if (limiter)
 682         {
 683           rate_limiter_send_delayed_change_now (monitor, limiter, get_time_msecs ());
 684           if (event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT)
 685             limiter->send_virtual_changes_done_at = 0;
 686           else
 687             rate_limiter_send_virtual_changes_done_now (monitor, limiter);
 688           update_rate_limiter_timeout (monitor, 0);
 689         }
 690       emit_in_idle (monitor, child, other_file, event_type);
 691     }
 692   else
 693     {
 694       /* Changed event, rate limit */
 695       time_now = get_time_msecs ();
 696       emit_now = TRUE;
 697
 698       if (limiter)
 699         {
 700           since_last = time_difference (limiter->last_sent_change_time, time_now);
 701           if (since_last < monitor->priv->rate_limit_msec)
 702             {
 703               /* We ignore this change, but arm a timer so that we can fire it later if we
 704                  don't get any other events (that kill this timeout) */
 705               emit_now = FALSE;
 706               if (limiter->send_delayed_change_at == 0)
 707                 {
 708                   limiter->send_delayed_change_at = time_now + monitor->priv->rate_limit_msec;
 709                   update_rate_limiter_timeout (monitor, limiter->send_delayed_change_at);
 710                 }
 711             }
 712         }
 713
 714       if (limiter == NULL)
 715         limiter = new_limiter (monitor, child);
 716
 717       if (emit_now)
 718         {
 719           emit_in_idle (monitor, child, other_file, event_type);
 720
 721           limiter->last_sent_change_time = time_now;
 722           limiter->send_delayed_change_at = 0;
 723           /* Set a timeout of 2*rate limit so that we can clear out the change from the hash eventualy */
 724           update_rate_limiter_timeout (monitor, time_now + 2 * monitor->priv->rate_limit_msec);
 725         }
 726
 727       /* Schedule a virtual change done. This is removed if we get a real one, and
 728          postponed if we get more change events. */
 729
 730       limiter->send_virtual_changes_done_at = time_now + DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS * 1000;
 731       update_rate_limiter_timeout (monitor, limiter->send_virtual_changes_done_at);
 732     }
 733 }