1 /* GIO - GLib Input, Output and Streaming Library
3 * Copyright (C) 2006-2007 Red Hat, Inc.
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.
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.
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.
20 * Author: Alexander Larsson <alexl@redhat.com>
26 #include "gfilemonitor.h"
27 #include "gioenumtypes.h"
34 typedef struct _FileChange FileChange;
35 static void file_change_free (FileChange *change);
38 * SECTION:gfilemonitor
39 * @short_description: File Monitor
42 * Monitors a file or directory for changes.
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().
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).
58 G_LOCK_DEFINE_STATIC(cancelled);
65 /* work around a limitation of the aliasing foo */
68 G_DEFINE_ABSTRACT_TYPE (GFileMonitor, g_file_monitor, G_TYPE_OBJECT);
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 */
77 struct _GFileMonitorPrivate {
81 /* Rate limiting change events */
82 GHashTable *rate_limiter;
84 GSource *pending_file_change_source;
85 GSList *pending_file_changes; /* FileChange */
88 guint32 timeout_fires_at;
90 GMainContext *context;
100 g_file_monitor_set_property (GObject *object,
105 GFileMonitor *monitor;
107 monitor = G_FILE_MONITOR (object);
111 case PROP_RATE_LIMIT:
112 g_file_monitor_set_rate_limit (monitor, g_value_get_int (value));
116 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
122 g_file_monitor_get_property (GObject *object,
127 GFileMonitor *monitor;
128 GFileMonitorPrivate *priv;
130 monitor = G_FILE_MONITOR (object);
131 priv = monitor->priv;
135 case PROP_RATE_LIMIT:
136 g_value_set_int (value, priv->rate_limit_msec);
141 g_value_set_boolean (value, priv->cancelled);
142 G_UNLOCK (cancelled);
146 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
151 #define DEFAULT_RATE_LIMIT_MSECS 800
152 #define DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS 2
154 static guint signals[LAST_SIGNAL] = { 0 };
157 rate_limiter_free (RateLimiter *limiter)
159 g_object_unref (limiter->file);
160 g_slice_free (RateLimiter, limiter);
164 g_file_monitor_finalize (GObject *object)
166 GFileMonitor *monitor;
168 monitor = G_FILE_MONITOR (object);
170 if (monitor->priv->timeout)
172 g_source_destroy (monitor->priv->timeout);
173 g_source_unref (monitor->priv->timeout);
176 g_hash_table_destroy (monitor->priv->rate_limiter);
178 if (monitor->priv->context)
179 g_main_context_unref (monitor->priv->context);
181 G_OBJECT_CLASS (g_file_monitor_parent_class)->finalize (object);
185 g_file_monitor_dispose (GObject *object)
187 GFileMonitor *monitor;
188 GFileMonitorPrivate *priv;
190 monitor = G_FILE_MONITOR (object);
191 priv = monitor->priv;
193 if (priv->pending_file_change_source)
195 g_source_destroy (priv->pending_file_change_source);
196 g_source_unref (priv->pending_file_change_source);
197 priv->pending_file_change_source = NULL;
199 g_slist_foreach (priv->pending_file_changes, (GFunc) file_change_free, NULL);
200 g_slist_free (priv->pending_file_changes);
201 priv->pending_file_changes = NULL;
203 /* Make sure we cancel on last unref */
204 g_file_monitor_cancel (monitor);
206 G_OBJECT_CLASS (g_file_monitor_parent_class)->dispose (object);
210 g_file_monitor_class_init (GFileMonitorClass *klass)
212 GObjectClass *object_class;
214 g_type_class_add_private (klass, sizeof (GFileMonitorPrivate));
216 object_class = G_OBJECT_CLASS (klass);
217 object_class->finalize = g_file_monitor_finalize;
218 object_class->dispose = g_file_monitor_dispose;
219 object_class->get_property = g_file_monitor_get_property;
220 object_class->set_property = g_file_monitor_set_property;
223 * GFileMonitor::changed:
224 * @monitor: a #GFileMonitor.
226 * @other_file: a #GFile or #NULL.
227 * @event_type: a #GFileMonitorEvent.
229 * Emitted when @file has been changed.
231 * If using #G_FILE_MONITOR_SEND_MOVED flag and @event_type is
232 * #G_FILE_MONITOR_SEND_MOVED, @file will be set to a #GFile containing the
233 * old path, and @other_file will be set to a #GFile containing the new path.
235 * In all the other cases, @other_file will be set to #NULL.
238 g_signal_new (I_("changed"),
241 G_STRUCT_OFFSET (GFileMonitorClass, changed),
243 g_cclosure_marshal_generic,
245 G_TYPE_FILE, G_TYPE_FILE, G_TYPE_FILE_MONITOR_EVENT);
247 g_object_class_install_property (object_class,
249 g_param_spec_int ("rate-limit",
251 P_("The limit of the monitor to watch for changes, in milliseconds"),
253 DEFAULT_RATE_LIMIT_MSECS,
255 G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
257 g_object_class_install_property (object_class,
259 g_param_spec_boolean ("cancelled",
261 P_("Whether the monitor has been cancelled"),
264 G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
268 g_file_monitor_init (GFileMonitor *monitor)
270 monitor->priv = G_TYPE_INSTANCE_GET_PRIVATE (monitor,
272 GFileMonitorPrivate);
273 monitor->priv->rate_limit_msec = DEFAULT_RATE_LIMIT_MSECS;
274 monitor->priv->rate_limiter = g_hash_table_new_full (g_file_hash, (GEqualFunc)g_file_equal,
275 NULL, (GDestroyNotify) rate_limiter_free);
276 monitor->priv->context = g_main_context_get_thread_default ();
280 * g_file_monitor_is_cancelled:
281 * @monitor: a #GFileMonitor
283 * Returns whether the monitor is canceled.
285 * Returns: %TRUE if monitor is canceled. %FALSE otherwise.
288 g_file_monitor_is_cancelled (GFileMonitor *monitor)
292 g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
295 res = monitor->priv->cancelled;
296 G_UNLOCK (cancelled);
302 * g_file_monitor_cancel:
303 * @monitor: a #GFileMonitor.
305 * Cancels a file monitor.
307 * Returns: %TRUE if monitor was cancelled.
310 g_file_monitor_cancel (GFileMonitor* monitor)
312 GFileMonitorClass *klass;
314 g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
317 if (monitor->priv->cancelled)
319 G_UNLOCK (cancelled);
323 monitor->priv->cancelled = TRUE;
324 G_UNLOCK (cancelled);
326 g_object_notify (G_OBJECT (monitor), "cancelled");
328 klass = G_FILE_MONITOR_GET_CLASS (monitor);
329 return (* klass->cancel) (monitor);
333 * g_file_monitor_set_rate_limit:
334 * @monitor: a #GFileMonitor.
335 * @limit_msecs: a non-negative integer with the limit in milliseconds
336 * to poll for changes
338 * Sets the rate limit to which the @monitor will report
339 * consecutive change events to the same file.
342 g_file_monitor_set_rate_limit (GFileMonitor *monitor,
345 GFileMonitorPrivate *priv;
347 g_return_if_fail (G_IS_FILE_MONITOR (monitor));
348 g_return_if_fail (limit_msecs >= 0);
350 priv = monitor->priv;
351 if (priv->rate_limit_msec != limit_msecs)
353 monitor->priv->rate_limit_msec = limit_msecs;
354 g_object_notify (G_OBJECT (monitor), "rate-limit");
361 GFileMonitorEvent event_type;
365 file_change_free (FileChange *change)
367 g_object_unref (change->child);
368 if (change->other_file)
369 g_object_unref (change->other_file);
371 g_slice_free (FileChange, change);
375 emit_cb (gpointer data)
377 GFileMonitor *monitor = G_FILE_MONITOR (data);
378 GSList *pending, *iter;
380 pending = g_slist_reverse (monitor->priv->pending_file_changes);
381 monitor->priv->pending_file_changes = NULL;
382 if (monitor->priv->pending_file_change_source)
384 g_source_unref (monitor->priv->pending_file_change_source);
385 monitor->priv->pending_file_change_source = NULL;
388 g_object_ref (monitor);
389 for (iter = pending; iter; iter = iter->next)
391 FileChange *change = iter->data;
392 g_signal_emit (monitor, signals[CHANGED], 0,
393 change->child, change->other_file, change->event_type);
394 file_change_free (change);
396 g_slist_free (pending);
397 g_object_unref (monitor);
403 emit_in_idle (GFileMonitor *monitor,
406 GFileMonitorEvent event_type)
410 GFileMonitorPrivate *priv;
412 priv = monitor->priv;
414 change = g_slice_new (FileChange);
416 change->child = g_object_ref (child);
418 change->other_file = g_object_ref (other_file);
420 change->other_file = NULL;
421 change->event_type = event_type;
423 if (!priv->pending_file_change_source)
425 source = g_idle_source_new ();
426 priv->pending_file_change_source = source;
427 g_source_set_priority (source, 0);
429 /* We don't ref monitor here - instead dispose will free any
432 g_source_set_callback (source, emit_cb, monitor, NULL);
433 g_source_attach (source, monitor->priv->context);
435 /* We reverse this in the processor */
436 priv->pending_file_changes = g_slist_prepend (priv->pending_file_changes, change);
440 get_time_msecs (void)
442 return g_thread_gettime() / (1000 * 1000);
446 time_difference (guint32 from, guint32 to)
453 /* Change event rate limiting support: */
456 new_limiter (GFileMonitor *monitor,
459 RateLimiter *limiter;
461 limiter = g_slice_new0 (RateLimiter);
462 limiter->file = g_object_ref (file);
463 g_hash_table_insert (monitor->priv->rate_limiter, file, limiter);
469 rate_limiter_send_virtual_changes_done_now (GFileMonitor *monitor,
470 RateLimiter *limiter)
472 if (limiter->send_virtual_changes_done_at != 0)
474 emit_in_idle (monitor, limiter->file, NULL,
475 G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT);
476 limiter->send_virtual_changes_done_at = 0;
481 rate_limiter_send_delayed_change_now (GFileMonitor *monitor,
482 RateLimiter *limiter,
485 if (limiter->send_delayed_change_at != 0)
487 emit_in_idle (monitor,
489 G_FILE_MONITOR_EVENT_CHANGED);
490 limiter->send_delayed_change_at = 0;
491 limiter->last_sent_change_time = time_now;
498 GFileMonitor *monitor;
502 calc_min_time (GFileMonitor *monitor,
503 RateLimiter *limiter,
512 if (limiter->last_sent_change_time != 0)
514 /* Set a timeout at 2*rate limit so that we can clear out the change from the hash eventualy */
515 expire_at = limiter->last_sent_change_time + 2 * monitor->priv->rate_limit_msec;
517 if (time_difference (time_now, expire_at) > 0)
520 *min_time = MIN (*min_time,
521 time_difference (time_now, expire_at));
525 if (limiter->send_delayed_change_at != 0)
528 *min_time = MIN (*min_time,
529 time_difference (time_now, limiter->send_delayed_change_at));
532 if (limiter->send_virtual_changes_done_at != 0)
535 *min_time = MIN (*min_time,
536 time_difference (time_now, limiter->send_virtual_changes_done_at));
543 foreach_rate_limiter_fire (gpointer key,
547 RateLimiter *limiter = value;
548 ForEachData *data = user_data;
550 if (limiter->send_delayed_change_at != 0 &&
551 time_difference (data->time_now, limiter->send_delayed_change_at) == 0)
552 rate_limiter_send_delayed_change_now (data->monitor, limiter, data->time_now);
554 if (limiter->send_virtual_changes_done_at != 0 &&
555 time_difference (data->time_now, limiter->send_virtual_changes_done_at) == 0)
556 rate_limiter_send_virtual_changes_done_now (data->monitor, limiter);
558 return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
562 rate_limiter_timeout (gpointer timeout_data)
564 GFileMonitor *monitor = timeout_data;
568 data.min_time = G_MAXUINT32;
569 data.monitor = monitor;
570 data.time_now = get_time_msecs ();
571 g_hash_table_foreach_remove (monitor->priv->rate_limiter,
572 foreach_rate_limiter_fire,
575 /* Remove old timeout */
576 if (monitor->priv->timeout)
578 g_source_destroy (monitor->priv->timeout);
579 g_source_unref (monitor->priv->timeout);
580 monitor->priv->timeout = NULL;
581 monitor->priv->timeout_fires_at = 0;
584 /* Set up new timeout */
585 if (data.min_time != G_MAXUINT32)
587 source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
588 g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
589 g_source_attach (source, monitor->priv->context);
591 monitor->priv->timeout = source;
592 monitor->priv->timeout_fires_at = data.time_now + data.min_time;
599 foreach_rate_limiter_update (gpointer key,
603 RateLimiter *limiter = value;
604 ForEachData *data = user_data;
606 return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
610 update_rate_limiter_timeout (GFileMonitor *monitor,
616 if (monitor->priv->timeout_fires_at != 0 && new_time != 0 &&
617 time_difference (new_time, monitor->priv->timeout_fires_at) == 0)
618 return; /* Nothing to do, we already fire earlier than that */
620 data.min_time = G_MAXUINT32;
621 data.monitor = monitor;
622 data.time_now = get_time_msecs ();
623 g_hash_table_foreach_remove (monitor->priv->rate_limiter,
624 foreach_rate_limiter_update,
627 /* Remove old timeout */
628 if (monitor->priv->timeout)
630 g_source_destroy (monitor->priv->timeout);
631 g_source_unref (monitor->priv->timeout);
632 monitor->priv->timeout_fires_at = 0;
633 monitor->priv->timeout = NULL;
636 /* Set up new timeout */
637 if (data.min_time != G_MAXUINT32)
639 source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
640 g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
641 g_source_attach (source, monitor->priv->context);
643 monitor->priv->timeout = source;
644 monitor->priv->timeout_fires_at = data.time_now + data.min_time;
649 * g_file_monitor_emit_event:
650 * @monitor: a #GFileMonitor.
652 * @other_file: a #GFile.
653 * @event_type: a set of #GFileMonitorEvent flags.
655 * Emits the #GFileMonitor::changed signal if a change
656 * has taken place. Should be called from file monitor
657 * implementations only.
659 * The signal will be emitted from an idle handler (in the <link
660 * linkend="g-main-context-push-thread-default">thread-default main
664 g_file_monitor_emit_event (GFileMonitor *monitor,
667 GFileMonitorEvent event_type)
669 guint32 time_now, since_last;
671 RateLimiter *limiter;
673 g_return_if_fail (G_IS_FILE_MONITOR (monitor));
674 g_return_if_fail (G_IS_FILE (child));
676 limiter = g_hash_table_lookup (monitor->priv->rate_limiter, child);
678 if (event_type != G_FILE_MONITOR_EVENT_CHANGED)
682 rate_limiter_send_delayed_change_now (monitor, limiter, get_time_msecs ());
683 if (event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT)
684 limiter->send_virtual_changes_done_at = 0;
686 rate_limiter_send_virtual_changes_done_now (monitor, limiter);
687 update_rate_limiter_timeout (monitor, 0);
689 emit_in_idle (monitor, child, other_file, event_type);
693 /* Changed event, rate limit */
694 time_now = get_time_msecs ();
699 since_last = time_difference (limiter->last_sent_change_time, time_now);
700 if (since_last < monitor->priv->rate_limit_msec)
702 /* We ignore this change, but arm a timer so that we can fire it later if we
703 don't get any other events (that kill this timeout) */
705 if (limiter->send_delayed_change_at == 0)
707 limiter->send_delayed_change_at = time_now + monitor->priv->rate_limit_msec;
708 update_rate_limiter_timeout (monitor, limiter->send_delayed_change_at);
714 limiter = new_limiter (monitor, child);
718 emit_in_idle (monitor, child, other_file, event_type);
720 limiter->last_sent_change_time = time_now;
721 limiter->send_delayed_change_at = 0;
722 /* Set a timeout of 2*rate limit so that we can clear out the change from the hash eventualy */
723 update_rate_limiter_timeout (monitor, time_now + 2 * monitor->priv->rate_limit_msec);
726 /* Schedule a virtual change done. This is removed if we get a real one, and
727 postponed if we get more change events. */
729 limiter->send_virtual_changes_done_at = time_now + DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS * 1000;
730 update_rate_limiter_timeout (monitor, limiter->send_virtual_changes_done_at);