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 "gio-marshal.h"
28 #include "gioenumtypes.h"
36 * SECTION:gfilemonitor
37 * @short_description: File Monitor
40 * Monitors a file or directory for changes.
42 * To obtain a #GFileMonitor for a file or directory, use
43 * g_file_monitor(), g_file_monitor_file(), or
44 * g_file_monitor_directory().
46 * To get informed about changes to the file or directory you
47 * are monitoring, connect to the #GFileMonitor::changed signal.
50 G_LOCK_DEFINE_STATIC(cancelled);
57 /* work around a limitation of the aliasing foo */
60 G_DEFINE_ABSTRACT_TYPE (GFileMonitor, g_file_monitor, G_TYPE_OBJECT);
64 guint32 last_sent_change_time; /* 0 == not sent */
65 guint32 send_delayed_change_at; /* 0 == never */
66 guint32 send_virtual_changes_done_at; /* 0 == never */
69 struct _GFileMonitorPrivate {
73 /* Rate limiting change events */
74 GHashTable *rate_limiter;
77 guint32 timeout_fires_at;
87 g_file_monitor_set_property (GObject *object,
92 GFileMonitor *monitor;
94 monitor = G_FILE_MONITOR (object);
99 g_file_monitor_set_rate_limit (monitor, g_value_get_int (value));
103 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
109 g_file_monitor_get_property (GObject *object,
114 GFileMonitor *monitor;
115 GFileMonitorPrivate *priv;
117 monitor = G_FILE_MONITOR (object);
118 priv = monitor->priv;
122 case PROP_RATE_LIMIT:
123 g_value_set_int (value, priv->rate_limit_msec);
128 g_value_set_boolean (value, priv->cancelled);
129 G_UNLOCK (cancelled);
133 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
138 #define DEFAULT_RATE_LIMIT_MSECS 800
139 #define DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS 2
141 static guint signals[LAST_SIGNAL] = { 0 };
144 rate_limiter_free (RateLimiter *limiter)
146 g_object_unref (limiter->file);
147 g_slice_free (RateLimiter, limiter);
151 g_file_monitor_finalize (GObject *object)
153 GFileMonitor *monitor;
155 monitor = G_FILE_MONITOR (object);
157 if (monitor->priv->timeout)
159 g_source_destroy (monitor->priv->timeout);
160 g_source_unref (monitor->priv->timeout);
163 g_hash_table_destroy (monitor->priv->rate_limiter);
165 G_OBJECT_CLASS (g_file_monitor_parent_class)->finalize (object);
169 g_file_monitor_dispose (GObject *object)
171 GFileMonitor *monitor;
173 monitor = G_FILE_MONITOR (object);
175 /* Make sure we cancel on last unref */
176 g_file_monitor_cancel (monitor);
178 G_OBJECT_CLASS (g_file_monitor_parent_class)->dispose (object);
182 g_file_monitor_class_init (GFileMonitorClass *klass)
184 GObjectClass *object_class;
186 g_type_class_add_private (klass, sizeof (GFileMonitorPrivate));
188 object_class = G_OBJECT_CLASS (klass);
189 object_class->finalize = g_file_monitor_finalize;
190 object_class->dispose = g_file_monitor_dispose;
191 object_class->get_property = g_file_monitor_get_property;
192 object_class->set_property = g_file_monitor_set_property;
195 * GFileMonitor::changed:
196 * @monitor: a #GFileMonitor.
198 * @other_file: a #GFile.
199 * @event_type: a #GFileMonitorEvent.
201 * Emitted when a file has been changed.
204 g_signal_new (I_("changed"),
207 G_STRUCT_OFFSET (GFileMonitorClass, changed),
209 _gio_marshal_VOID__OBJECT_OBJECT_ENUM,
211 G_TYPE_FILE, G_TYPE_FILE, G_TYPE_FILE_MONITOR_EVENT);
213 g_object_class_install_property (object_class,
215 g_param_spec_int ("rate-limit",
217 P_("The limit of the monitor to watch for changes, in milliseconds"),
219 DEFAULT_RATE_LIMIT_MSECS,
221 G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
223 g_object_class_install_property (object_class,
225 g_param_spec_boolean ("cancelled",
227 P_("Whether the monitor has been cancelled"),
230 G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
234 g_file_monitor_init (GFileMonitor *monitor)
236 monitor->priv = G_TYPE_INSTANCE_GET_PRIVATE (monitor,
238 GFileMonitorPrivate);
239 monitor->priv->rate_limit_msec = DEFAULT_RATE_LIMIT_MSECS;
240 monitor->priv->rate_limiter = g_hash_table_new_full (g_file_hash, (GEqualFunc)g_file_equal,
241 NULL, (GDestroyNotify) rate_limiter_free);
245 * g_file_monitor_is_cancelled:
246 * @monitor: a #GFileMonitor
248 * Returns whether the monitor is canceled.
250 * Returns: %TRUE if monitor is canceled. %FALSE otherwise.
253 g_file_monitor_is_cancelled (GFileMonitor *monitor)
257 g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
260 res = monitor->priv->cancelled;
261 G_UNLOCK (cancelled);
267 * g_file_monitor_cancel:
268 * @monitor: a #GFileMonitor.
270 * Cancels a file monitor.
272 * Returns: %TRUE if monitor was cancelled.
275 g_file_monitor_cancel (GFileMonitor* monitor)
277 GFileMonitorClass *klass;
279 g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
282 if (monitor->priv->cancelled)
284 G_UNLOCK (cancelled);
288 monitor->priv->cancelled = TRUE;
289 G_UNLOCK (cancelled);
291 g_object_notify (G_OBJECT (monitor), "cancelled");
293 klass = G_FILE_MONITOR_GET_CLASS (monitor);
294 return (* klass->cancel) (monitor);
298 * g_file_monitor_set_rate_limit:
299 * @monitor: a #GFileMonitor.
300 * @limit_msecs: a integer with the limit in milliseconds to
303 * Sets the rate limit to which the @monitor will report
304 * consecutive change events to the same file.
308 g_file_monitor_set_rate_limit (GFileMonitor *monitor,
311 GFileMonitorPrivate *priv;
313 g_return_if_fail (G_IS_FILE_MONITOR (monitor));
315 priv = monitor->priv;
316 if (priv->rate_limit_msec != limit_msecs)
318 monitor->priv->rate_limit_msec = limit_msecs;
319 g_object_notify (G_OBJECT (monitor), "rate-limit");
324 GFileMonitor *monitor;
327 GFileMonitorEvent event_type;
331 emit_cb (gpointer data)
333 FileChange *change = data;
334 g_signal_emit (change->monitor, signals[CHANGED], 0,
335 change->child, change->other_file, change->event_type);
340 file_change_free (FileChange *change)
342 g_object_unref (change->monitor);
343 g_object_unref (change->child);
344 if (change->other_file)
345 g_object_unref (change->other_file);
347 g_slice_free (FileChange, change);
351 emit_in_idle (GFileMonitor *monitor,
354 GFileMonitorEvent event_type)
359 change = g_slice_new (FileChange);
361 change->monitor = g_object_ref (monitor);
362 change->child = g_object_ref (child);
364 change->other_file = g_object_ref (other_file);
366 change->other_file = NULL;
367 change->event_type = event_type;
369 source = g_idle_source_new ();
370 g_source_set_priority (source, 0);
372 g_source_set_callback (source, emit_cb, change, (GDestroyNotify)file_change_free);
373 g_source_attach (source, NULL);
374 g_source_unref (source);
378 get_time_msecs (void)
380 return g_thread_gettime() / (1000 * 1000);
384 time_difference (guint32 from, guint32 to)
391 /* Change event rate limiting support: */
394 new_limiter (GFileMonitor *monitor,
397 RateLimiter *limiter;
399 limiter = g_slice_new0 (RateLimiter);
400 limiter->file = g_object_ref (file);
401 g_hash_table_insert (monitor->priv->rate_limiter, file, limiter);
407 rate_limiter_send_virtual_changes_done_now (GFileMonitor *monitor,
408 RateLimiter *limiter)
410 if (limiter->send_virtual_changes_done_at != 0)
412 emit_in_idle (monitor, limiter->file, NULL,
413 G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT);
414 limiter->send_virtual_changes_done_at = 0;
419 rate_limiter_send_delayed_change_now (GFileMonitor *monitor,
420 RateLimiter *limiter,
423 if (limiter->send_delayed_change_at != 0)
425 emit_in_idle (monitor,
427 G_FILE_MONITOR_EVENT_CHANGED);
428 limiter->send_delayed_change_at = 0;
429 limiter->last_sent_change_time = time_now;
436 GFileMonitor *monitor;
440 calc_min_time (GFileMonitor *monitor,
441 RateLimiter *limiter,
450 if (limiter->last_sent_change_time != 0)
452 /* Set a timeout at 2*rate limit so that we can clear out the change from the hash eventualy */
453 expire_at = limiter->last_sent_change_time + 2 * monitor->priv->rate_limit_msec;
455 if (time_difference (time_now, expire_at) > 0)
458 *min_time = MIN (*min_time,
459 time_difference (time_now, expire_at));
463 if (limiter->send_delayed_change_at != 0)
466 *min_time = MIN (*min_time,
467 time_difference (time_now, limiter->send_delayed_change_at));
470 if (limiter->send_virtual_changes_done_at != 0)
473 *min_time = MIN (*min_time,
474 time_difference (time_now, limiter->send_virtual_changes_done_at));
481 foreach_rate_limiter_fire (gpointer key,
485 RateLimiter *limiter = value;
486 ForEachData *data = user_data;
488 if (limiter->send_delayed_change_at != 0 &&
489 time_difference (data->time_now, limiter->send_delayed_change_at) == 0)
490 rate_limiter_send_delayed_change_now (data->monitor, limiter, data->time_now);
492 if (limiter->send_virtual_changes_done_at != 0 &&
493 time_difference (data->time_now, limiter->send_virtual_changes_done_at) == 0)
494 rate_limiter_send_virtual_changes_done_now (data->monitor, limiter);
496 return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
500 rate_limiter_timeout (gpointer timeout_data)
502 GFileMonitor *monitor = timeout_data;
506 data.min_time = G_MAXUINT32;
507 data.monitor = monitor;
508 data.time_now = get_time_msecs ();
509 g_hash_table_foreach_remove (monitor->priv->rate_limiter,
510 foreach_rate_limiter_fire,
513 /* Remove old timeout */
514 if (monitor->priv->timeout)
516 g_source_destroy (monitor->priv->timeout);
517 g_source_unref (monitor->priv->timeout);
518 monitor->priv->timeout = NULL;
519 monitor->priv->timeout_fires_at = 0;
522 /* Set up new timeout */
523 if (data.min_time != G_MAXUINT32)
525 source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
526 g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
527 g_source_attach (source, NULL);
529 monitor->priv->timeout = source;
530 monitor->priv->timeout_fires_at = data.time_now + data.min_time;
537 foreach_rate_limiter_update (gpointer key,
541 RateLimiter *limiter = value;
542 ForEachData *data = user_data;
544 return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
548 update_rate_limiter_timeout (GFileMonitor *monitor,
554 if (monitor->priv->timeout_fires_at != 0 && new_time != 0 &&
555 time_difference (new_time, monitor->priv->timeout_fires_at) == 0)
556 return; /* Nothing to do, we already fire earlier than that */
558 data.min_time = G_MAXUINT32;
559 data.monitor = monitor;
560 data.time_now = get_time_msecs ();
561 g_hash_table_foreach_remove (monitor->priv->rate_limiter,
562 foreach_rate_limiter_update,
565 /* Remove old timeout */
566 if (monitor->priv->timeout)
568 g_source_destroy (monitor->priv->timeout);
569 g_source_unref (monitor->priv->timeout);
570 monitor->priv->timeout_fires_at = 0;
571 monitor->priv->timeout = NULL;
574 /* Set up new timeout */
575 if (data.min_time != G_MAXUINT32)
577 source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
578 g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
579 g_source_attach (source, NULL);
581 monitor->priv->timeout = source;
582 monitor->priv->timeout_fires_at = data.time_now + data.min_time;
587 * g_file_monitor_emit_event:
588 * @monitor: a #GFileMonitor.
590 * @other_file: a #GFile.
591 * @event_type: a set of #GFileMonitorEvent flags.
593 * Emits the #GFileMonitor::changed signal if a change
594 * has taken place. Should be called from file monitor
595 * implementations only.
597 * The signal will be emitted from an idle handler.
600 g_file_monitor_emit_event (GFileMonitor *monitor,
603 GFileMonitorEvent event_type)
605 guint32 time_now, since_last;
607 RateLimiter *limiter;
609 g_return_if_fail (G_IS_FILE_MONITOR (monitor));
610 g_return_if_fail (G_IS_FILE (child));
612 limiter = g_hash_table_lookup (monitor->priv->rate_limiter, child);
614 if (event_type != G_FILE_MONITOR_EVENT_CHANGED)
618 rate_limiter_send_delayed_change_now (monitor, limiter, get_time_msecs ());
619 if (event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT)
620 limiter->send_virtual_changes_done_at = 0;
622 rate_limiter_send_virtual_changes_done_now (monitor, limiter);
623 update_rate_limiter_timeout (monitor, 0);
625 emit_in_idle (monitor, child, other_file, event_type);
629 /* Changed event, rate limit */
630 time_now = get_time_msecs ();
635 since_last = time_difference (limiter->last_sent_change_time, time_now);
636 if (since_last < monitor->priv->rate_limit_msec)
638 /* We ignore this change, but arm a timer so that we can fire it later if we
639 don't get any other events (that kill this timeout) */
641 if (limiter->send_delayed_change_at == 0)
643 limiter->send_delayed_change_at = time_now + monitor->priv->rate_limit_msec;
644 update_rate_limiter_timeout (monitor, limiter->send_delayed_change_at);
650 limiter = new_limiter (monitor, child);
654 emit_in_idle (monitor, child, other_file, event_type);
656 limiter->last_sent_change_time = time_now;
657 limiter->send_delayed_change_at = 0;
658 /* Set a timeout of 2*rate limit so that we can clear out the change from the hash eventualy */
659 update_rate_limiter_timeout (monitor, time_now + 2 * monitor->priv->rate_limit_msec);
662 /* Schedule a virtual change done. This is removed if we get a real one, and
663 postponed if we get more change events. */
665 limiter->send_virtual_changes_done_at = time_now + DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS * 1000;
666 update_rate_limiter_timeout (monitor, limiter->send_virtual_changes_done_at);
670 #define __G_FILE_MONITOR_C__
671 #include "gioaliasdef.c"