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 2.1 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, see <http://www.gnu.org/licenses/>.
17  *
18  * Author: Alexander Larsson <alexl@redhat.com>
19  */
20 
21 #include "config.h"
22 #include <string.h>
23 
24 #include "gfilemonitor.h"
25 #include "gioenumtypes.h"
26 #include "gmarshal-internal.h"
27 #include "gfile.h"
28 #include "gvfs.h"
29 #include "glibintl.h"
30 
31 /**
32  * SECTION:gfilemonitor
33  * @short_description: File Monitor
34  * @include: gio/gio.h
35  *
36  * Monitors a file or directory for changes.
37  *
38  * To obtain a #GFileMonitor for a file or directory, use
39  * g_file_monitor(), g_file_monitor_file(), or
40  * g_file_monitor_directory().
41  *
42  * To get informed about changes to the file or directory you are
43  * monitoring, connect to the #GFileMonitor::changed signal. The
44  * signal will be emitted in the
45  * [thread-default main context][g-main-context-push-thread-default]
46  * of the thread that the monitor was created in
47  * (though if the global default main context is blocked, this may
48  * cause notifications to be blocked even if the thread-default
49  * context is still running).
50  **/
51 
52 #define DEFAULT_RATE_LIMIT_MSECS 800
53 
54 struct _GFileMonitorPrivate
55 {
56   gboolean cancelled;
57 };
58 
59 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GFileMonitor, g_file_monitor, G_TYPE_OBJECT)
60 
61 enum
62 {
63   PROP_0,
64   PROP_RATE_LIMIT,
65   PROP_CANCELLED
66 };
67 
68 static guint g_file_monitor_changed_signal;
69 
70 static void
g_file_monitor_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)71 g_file_monitor_set_property (GObject      *object,
72                              guint         prop_id,
73                              const GValue *value,
74                              GParamSpec   *pspec)
75 {
76   //GFileMonitor *monitor;
77 
78   //monitor = G_FILE_MONITOR (object);
79 
80   switch (prop_id)
81     {
82     case PROP_RATE_LIMIT:
83       /* not supported by default */
84       break;
85 
86     default:
87       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
88       break;
89     }
90 }
91 
92 static void
g_file_monitor_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)93 g_file_monitor_get_property (GObject    *object,
94                              guint       prop_id,
95                              GValue     *value,
96                              GParamSpec *pspec)
97 {
98   switch (prop_id)
99     {
100     case PROP_RATE_LIMIT:
101       /* we expect this to be overridden... */
102       g_value_set_int (value, DEFAULT_RATE_LIMIT_MSECS);
103       break;
104 
105     case PROP_CANCELLED:
106       //g_mutex_lock (&fms->lock);
107       g_value_set_boolean (value, FALSE);//fms->cancelled);
108       //g_mutex_unlock (&fms->lock);
109       break;
110 
111     default:
112       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
113       break;
114     }
115 }
116 
117 static void
g_file_monitor_dispose(GObject * object)118 g_file_monitor_dispose (GObject *object)
119 {
120   GFileMonitor *monitor = G_FILE_MONITOR (object);
121 
122   /* Make sure we cancel on last unref */
123   g_file_monitor_cancel (monitor);
124 
125   G_OBJECT_CLASS (g_file_monitor_parent_class)->dispose (object);
126 }
127 
128 static void
g_file_monitor_init(GFileMonitor * monitor)129 g_file_monitor_init (GFileMonitor *monitor)
130 {
131   monitor->priv = g_file_monitor_get_instance_private (monitor);
132 }
133 
134 static void
g_file_monitor_class_init(GFileMonitorClass * klass)135 g_file_monitor_class_init (GFileMonitorClass *klass)
136 {
137   GObjectClass *object_class;
138 
139   object_class = G_OBJECT_CLASS (klass);
140   object_class->dispose = g_file_monitor_dispose;
141   object_class->get_property = g_file_monitor_get_property;
142   object_class->set_property = g_file_monitor_set_property;
143 
144   /**
145    * GFileMonitor::changed:
146    * @monitor: a #GFileMonitor.
147    * @file: a #GFile.
148    * @other_file: (nullable): a #GFile or #NULL.
149    * @event_type: a #GFileMonitorEvent.
150    *
151    * Emitted when @file has been changed.
152    *
153    * If using %G_FILE_MONITOR_WATCH_MOVES on a directory monitor, and
154    * the information is available (and if supported by the backend),
155    * @event_type may be %G_FILE_MONITOR_EVENT_RENAMED,
156    * %G_FILE_MONITOR_EVENT_MOVED_IN or %G_FILE_MONITOR_EVENT_MOVED_OUT.
157    *
158    * In all cases @file will be a child of the monitored directory.  For
159    * renames, @file will be the old name and @other_file is the new
160    * name.  For "moved in" events, @file is the name of the file that
161    * appeared and @other_file is the old name that it was moved from (in
162    * another directory).  For "moved out" events, @file is the name of
163    * the file that used to be in this directory and @other_file is the
164    * name of the file at its new location.
165    *
166    * It makes sense to treat %G_FILE_MONITOR_EVENT_MOVED_IN as
167    * equivalent to %G_FILE_MONITOR_EVENT_CREATED and
168    * %G_FILE_MONITOR_EVENT_MOVED_OUT as equivalent to
169    * %G_FILE_MONITOR_EVENT_DELETED, with extra information.
170    * %G_FILE_MONITOR_EVENT_RENAMED is equivalent to a delete/create
171    * pair.  This is exactly how the events will be reported in the case
172    * that the %G_FILE_MONITOR_WATCH_MOVES flag is not in use.
173    *
174    * If using the deprecated flag %G_FILE_MONITOR_SEND_MOVED flag and @event_type is
175    * #G_FILE_MONITOR_EVENT_MOVED, @file will be set to a #GFile containing the
176    * old path, and @other_file will be set to a #GFile containing the new path.
177    *
178    * In all the other cases, @other_file will be set to #NULL.
179    **/
180   g_file_monitor_changed_signal = g_signal_new (I_("changed"),
181                                                 G_TYPE_FILE_MONITOR,
182                                                 G_SIGNAL_RUN_LAST,
183                                                 G_STRUCT_OFFSET (GFileMonitorClass, changed),
184                                                 NULL, NULL,
185                                                 _g_cclosure_marshal_VOID__OBJECT_OBJECT_ENUM,
186                                                 G_TYPE_NONE, 3,
187                                                 G_TYPE_FILE, G_TYPE_FILE, G_TYPE_FILE_MONITOR_EVENT);
188   g_signal_set_va_marshaller (g_file_monitor_changed_signal,
189                               G_TYPE_FROM_CLASS (klass),
190                               _g_cclosure_marshal_VOID__OBJECT_OBJECT_ENUMv);
191 
192   g_object_class_install_property (object_class, PROP_RATE_LIMIT,
193                                    g_param_spec_int ("rate-limit",
194                                                      P_("Rate limit"),
195                                                      P_("The limit of the monitor to watch for changes, in milliseconds"),
196                                                      0, G_MAXINT, DEFAULT_RATE_LIMIT_MSECS, G_PARAM_READWRITE |
197                                                      G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS));
198 
199   g_object_class_install_property (object_class, PROP_CANCELLED,
200                                    g_param_spec_boolean ("cancelled",
201                                                          P_("Cancelled"),
202                                                          P_("Whether the monitor has been cancelled"),
203                                                          FALSE, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
204 }
205 
206 /**
207  * g_file_monitor_is_cancelled:
208  * @monitor: a #GFileMonitor
209  *
210  * Returns whether the monitor is canceled.
211  *
212  * Returns: %TRUE if monitor is canceled. %FALSE otherwise.
213  **/
214 gboolean
g_file_monitor_is_cancelled(GFileMonitor * monitor)215 g_file_monitor_is_cancelled (GFileMonitor *monitor)
216 {
217   gboolean res;
218 
219   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
220 
221   res = monitor->priv->cancelled;
222 
223   return res;
224 }
225 
226 /**
227  * g_file_monitor_cancel:
228  * @monitor: a #GFileMonitor.
229  *
230  * Cancels a file monitor.
231  *
232  * Returns: always %TRUE
233  **/
234 gboolean
g_file_monitor_cancel(GFileMonitor * monitor)235 g_file_monitor_cancel (GFileMonitor *monitor)
236 {
237   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
238 
239   if (!monitor->priv->cancelled)
240     {
241       G_FILE_MONITOR_GET_CLASS (monitor)->cancel (monitor);
242 
243       monitor->priv->cancelled = TRUE;
244       g_object_notify (G_OBJECT (monitor), "cancelled");
245     }
246 
247   return TRUE;
248 }
249 
250 /**
251  * g_file_monitor_set_rate_limit:
252  * @monitor: a #GFileMonitor.
253  * @limit_msecs: a non-negative integer with the limit in milliseconds
254  *     to poll for changes
255  *
256  * Sets the rate limit to which the @monitor will report
257  * consecutive change events to the same file.
258  */
259 void
g_file_monitor_set_rate_limit(GFileMonitor * monitor,gint limit_msecs)260 g_file_monitor_set_rate_limit (GFileMonitor *monitor,
261                                gint          limit_msecs)
262 {
263   g_object_set (monitor, "rate-limit", limit_msecs, NULL);
264 }
265 
266 /**
267  * g_file_monitor_emit_event:
268  * @monitor: a #GFileMonitor.
269  * @child: a #GFile.
270  * @other_file: a #GFile.
271  * @event_type: a set of #GFileMonitorEvent flags.
272  *
273  * Emits the #GFileMonitor::changed signal if a change
274  * has taken place. Should be called from file monitor
275  * implementations only.
276  *
277  * Implementations are responsible to call this method from the
278  * [thread-default main context][g-main-context-push-thread-default] of the
279  * thread that the monitor was created in.
280  **/
281 void
g_file_monitor_emit_event(GFileMonitor * monitor,GFile * child,GFile * other_file,GFileMonitorEvent event_type)282 g_file_monitor_emit_event (GFileMonitor      *monitor,
283                            GFile             *child,
284                            GFile             *other_file,
285                            GFileMonitorEvent  event_type)
286 {
287   g_return_if_fail (G_IS_FILE_MONITOR (monitor));
288   g_return_if_fail (G_IS_FILE (child));
289   g_return_if_fail (!other_file || G_IS_FILE (other_file));
290 
291   if (monitor->priv->cancelled)
292     return;
293 
294   g_signal_emit (monitor, g_file_monitor_changed_signal, 0, child, other_file, event_type);
295 }
296