1 /* GIO - GLib Input, Output and Streaming Library
2 *
3 * Copyright (C) 2006-2007 Red Hat, Inc.
4 *
5 * SPDX-License-Identifier: LGPL-2.1-or-later
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General
18 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
19 *
20 * Author: Alexander Larsson <alexl@redhat.com>
21 */
22
23 #include "config.h"
24 #include <string.h>
25
26 #include "gpollfilemonitor.h"
27 #include "gfile.h"
28 #include "gfilemonitor.h"
29 #include "gfileinfo.h"
30
31
32 static gboolean g_poll_file_monitor_cancel (GFileMonitor* monitor);
33 static void schedule_poll_timeout (GPollFileMonitor* poll_monitor);
34
35 struct _GPollFileMonitor
36 {
37 GFileMonitor parent_instance;
38 GFile *file;
39 GFileInfo *last_info;
40 GSource *timeout;
41 };
42
43 #define POLL_TIME_SECS 5
44
45 #define g_poll_file_monitor_get_type _g_poll_file_monitor_get_type
46 G_DEFINE_TYPE (GPollFileMonitor, g_poll_file_monitor, G_TYPE_FILE_MONITOR)
47
48 static void
49 g_poll_file_monitor_finalize (GObject* object)
50 {
51 GPollFileMonitor* poll_monitor;
52
53 poll_monitor = G_POLL_FILE_MONITOR (object);
54
55 g_poll_file_monitor_cancel (G_FILE_MONITOR (poll_monitor));
56 g_object_unref (poll_monitor->file);
57 g_clear_object (&poll_monitor->last_info);
58
59 G_OBJECT_CLASS (g_poll_file_monitor_parent_class)->finalize (object);
60 }
61
62
63 static void
64 g_poll_file_monitor_class_init (GPollFileMonitorClass* klass)
65 {
66 GObjectClass* gobject_class = G_OBJECT_CLASS (klass);
67 GFileMonitorClass *file_monitor_class = G_FILE_MONITOR_CLASS (klass);
68
69 gobject_class->finalize = g_poll_file_monitor_finalize;
70
71 file_monitor_class->cancel = g_poll_file_monitor_cancel;
72 }
73
74 static void
75 g_poll_file_monitor_init (GPollFileMonitor* poll_monitor)
76 {
77 }
78
79 static int
80 calc_event_type (GFileInfo *last,
81 GFileInfo *new)
82 {
83 if (last == NULL && new == NULL)
84 return -1;
85
86 if (last == NULL && new != NULL)
87 return G_FILE_MONITOR_EVENT_CREATED;
88
89 if (last != NULL && new == NULL)
90 return G_FILE_MONITOR_EVENT_DELETED;
91
92 if (g_file_info_has_attribute (last, G_FILE_ATTRIBUTE_ETAG_VALUE) &&
93 g_file_info_has_attribute (new, G_FILE_ATTRIBUTE_ETAG_VALUE) &&
94 g_strcmp0 (g_file_info_get_etag (last), g_file_info_get_etag (new)) != 0)
95 return G_FILE_MONITOR_EVENT_CHANGED;
96
97 if (g_file_info_has_attribute (last, G_FILE_ATTRIBUTE_STANDARD_SIZE) &&
98 g_file_info_has_attribute (new, G_FILE_ATTRIBUTE_STANDARD_SIZE) &&
99 g_file_info_get_size (last) != g_file_info_get_size (new))
100 return G_FILE_MONITOR_EVENT_CHANGED;
101
102 return -1;
103 }
104
105 static void
106 got_new_info (GObject *source_object,
107 GAsyncResult *res,
108 gpointer user_data)
109 {
110 GPollFileMonitor* poll_monitor = user_data;
111 GFileInfo *info;
112 int event;
113
114 info = g_file_query_info_finish (poll_monitor->file, res, NULL);
115
116 if (!g_file_monitor_is_cancelled (G_FILE_MONITOR (poll_monitor)))
117 {
118 event = calc_event_type (poll_monitor->last_info, info);
119
120 if (event != -1)
121 {
122 g_file_monitor_emit_event (G_FILE_MONITOR (poll_monitor),
123 poll_monitor->file,
124 NULL, event);
125 /* We're polling so slowly anyway, so always emit the done hint */
126 if (!g_file_monitor_is_cancelled (G_FILE_MONITOR (poll_monitor)) &&
127 (event == G_FILE_MONITOR_EVENT_CHANGED || event == G_FILE_MONITOR_EVENT_CREATED))
128 g_file_monitor_emit_event (G_FILE_MONITOR (poll_monitor),
129 poll_monitor->file,
130 NULL, G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT);
131 }
132
133 if (poll_monitor->last_info)
134 {
135 g_object_unref (poll_monitor->last_info);
136 poll_monitor->last_info = NULL;
137 }
138
139 if (info)
140 poll_monitor->last_info = g_object_ref (info);
141
142 schedule_poll_timeout (poll_monitor);
143 }
144
145 if (info)
146 g_object_unref (info);
147
148 g_object_unref (poll_monitor);
149 }
150
151 static gboolean
152 poll_file_timeout (gpointer data)
153 {
154 GPollFileMonitor* poll_monitor = data;
155
156 g_source_unref (poll_monitor->timeout);
157 poll_monitor->timeout = NULL;
158
159 g_file_query_info_async (poll_monitor->file, G_FILE_ATTRIBUTE_ETAG_VALUE "," G_FILE_ATTRIBUTE_STANDARD_SIZE,
160 0, 0, NULL, got_new_info, g_object_ref (poll_monitor));
161
162 return G_SOURCE_REMOVE;
163 }
164
165 static void
166 schedule_poll_timeout (GPollFileMonitor* poll_monitor)
167 {
168 poll_monitor->timeout = g_timeout_source_new_seconds (POLL_TIME_SECS);
169 g_source_set_callback (poll_monitor->timeout, poll_file_timeout, poll_monitor, NULL);
170 g_source_attach (poll_monitor->timeout, g_main_context_get_thread_default ());
171 }
172
173 static void
174 got_initial_info (GObject *source_object,
175 GAsyncResult *res,
176 gpointer user_data)
177 {
178 GPollFileMonitor* poll_monitor = user_data;
179 GFileInfo *info;
180
181 info = g_file_query_info_finish (poll_monitor->file, res, NULL);
182
183 poll_monitor->last_info = info;
184
185 if (!g_file_monitor_is_cancelled (G_FILE_MONITOR (poll_monitor)))
186 schedule_poll_timeout (poll_monitor);
187
188 g_object_unref (poll_monitor);
189 }
190
191 /**
192 * _g_poll_file_monitor_new:
193 * @file: a #GFile.
194 *
195 * Polls @file for changes.
196 *
197 * Returns: a new #GFileMonitor for the given #GFile.
198 **/
199 GFileMonitor*
200 _g_poll_file_monitor_new (GFile *file)
201 {
202 GPollFileMonitor* poll_monitor;
203
204 poll_monitor = g_object_new (G_TYPE_POLL_FILE_MONITOR, NULL);
205
206 poll_monitor->file = g_object_ref (file);
207
208 g_file_query_info_async (file, G_FILE_ATTRIBUTE_ETAG_VALUE "," G_FILE_ATTRIBUTE_STANDARD_SIZE,
209 0, 0, NULL, got_initial_info, g_object_ref (poll_monitor));
210
211 return G_FILE_MONITOR (poll_monitor);
212 }
213
214 static gboolean
215 g_poll_file_monitor_cancel (GFileMonitor* monitor)
216 {
217 GPollFileMonitor *poll_monitor = G_POLL_FILE_MONITOR (monitor);
218
219 if (poll_monitor->timeout)
220 {
221 g_source_destroy (poll_monitor->timeout);
222 g_source_unref (poll_monitor->timeout);
223 poll_monitor->timeout = NULL;
224 }
225
226 return TRUE;
227 }