aboutsummaryrefslogtreecommitdiffstats
path: root/src/inotify_queue.c
blob: 5391a17152f91d7bb28e6b6fc791bc28f753f185 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
/*
 * Copyright (C) 2003-2010 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "inotify_queue.h"
#include "update.h"

#include <glib.h>

#include <string.h>

#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "inotify"

enum {
	/**
	 * Wait this long after the last change before calling
	 * update_enqueue().  This increases the probability that
	 * updates can be bundled.
	 */
	INOTIFY_UPDATE_DELAY_S = 5,
};

static GSList *inotify_queue;
static guint queue_source_id;

void
mpd_inotify_queue_init(void)
{
}

static void
free_callback(gpointer data, G_GNUC_UNUSED gpointer user_data)
{
	g_free(data);
}

void
mpd_inotify_queue_finish(void)
{
	if (queue_source_id != 0)
		g_source_remove(queue_source_id);

	g_slist_foreach(inotify_queue, free_callback, NULL);
	g_slist_free(inotify_queue);
}

static gboolean
mpd_inotify_run_update(G_GNUC_UNUSED gpointer data)
{
	unsigned id;

	while (inotify_queue != NULL) {
		char *uri_utf8 = inotify_queue->data;

		id = update_enqueue(uri_utf8, false);
		if (id == 0)
			/* retry later */
			return true;

		g_debug("updating '%s' job=%u", uri_utf8, id);

		g_free(uri_utf8);
		inotify_queue = g_slist_delete_link(inotify_queue,
						    inotify_queue);
	}

	/* done, remove the timer event by returning false */
	queue_source_id = 0;
	return false;
}

static bool
path_in(const char *path, const char *possible_parent)
{
	size_t length = strlen(possible_parent);

	return path[0] == 0 ||
		(memcmp(possible_parent, path, length) == 0 &&
		 (path[length] == 0 || path[length] == '/'));
}

void
mpd_inotify_enqueue(char *uri_utf8)
{
	GSList *old_queue = inotify_queue;

	if (queue_source_id != 0)
		g_source_remove(queue_source_id);
	queue_source_id = g_timeout_add_seconds(INOTIFY_UPDATE_DELAY_S,
					mpd_inotify_run_update, NULL);

	inotify_queue = NULL;
	while (old_queue != NULL) {
		char *current_uri = old_queue->data;

		if (path_in(uri_utf8, current_uri)) {
			/* already enqueued */
			g_free(uri_utf8);
			inotify_queue = g_slist_concat(inotify_queue,
						       old_queue);
			return;
		}

		old_queue = g_slist_delete_link(old_queue, old_queue);

		if (path_in(current_uri, uri_utf8))
			/* existing path is a sub-path of the new
			   path; we can dequeue the existing path and
			   update the new path instead */
			g_free(current_uri);
		else
			/* move the existing path to the new queue */
			inotify_queue = g_slist_prepend(inotify_queue,
							current_uri);
	}

	inotify_queue = g_slist_prepend(inotify_queue, uri_utf8);
}