Add D-Bus helper library for GLib integration

1 files changed, 391 insertions, 0 deletions

diff --git a/gdbus/watch.c b/gdbus/watch.c
new file mode 100644
index 00000000..7d7853fc
--- /dev/null
+++ b/gdbus/watch.c
@@ -0,0 +1,391 @@
+/*
+ *
+ *  D-Bus helper library
+ *
+ *  Copyright (C) 2004-2009  Marcel Holtmann <marcel@holtmann.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 St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+
+#include <glib.h>
+#include <dbus/dbus.h>
+
+#include "gdbus.h"
+
+#define info(fmt...)
+#define error(fmt...)
+#define debug(fmt...)
+
+static DBusHandlerResult name_exit_filter(DBusConnection *connection,
+					DBusMessage *message, void *user_data);
+
+static guint listener_id = 0;
+static GSList *name_listeners = NULL;
+
+struct name_callback {
+	GDBusWatchFunction conn_func;
+	GDBusWatchFunction disc_func;
+	void *user_data;
+	guint id;
+};
+
+struct name_data {
+	DBusConnection *connection;
+	char *name;
+	GSList *callbacks;
+};
+
+static struct name_data *name_data_find(DBusConnection *connection,
+							const char *name)
+{
+	GSList *current;
+
+	for (current = name_listeners;
+			current != NULL; current = current->next) {
+		struct name_data *data = current->data;
+
+		if (connection != data->connection)
+			continue;
+
+		if (name == NULL || g_str_equal(name, data->name))
+			return data;
+	}
+
+	return NULL;
+}
+
+static struct name_callback *name_callback_find(GSList *callbacks, guint id)
+{
+	GSList *current;
+
+	for (current = callbacks; current != NULL; current = current->next) {
+		struct name_callback *cb = current->data;
+		if (cb->id == id)
+			return cb;
+	}
+
+	return NULL;
+}
+
+static void name_data_call_and_free(struct name_data *data)
+{
+	GSList *l;
+
+	for (l = data->callbacks; l != NULL; l = l->next) {
+		struct name_callback *cb = l->data;
+		if (cb->disc_func)
+			cb->disc_func(data->connection, cb->user_data);
+		g_free(cb);
+	}
+
+	g_slist_free(data->callbacks);
+	g_free(data->name);
+	g_free(data);
+}
+
+static void name_data_free(struct name_data *data)
+{
+	GSList *l;
+
+	for (l = data->callbacks; l != NULL; l = l->next)
+		g_free(l->data);
+
+	g_slist_free(data->callbacks);
+	g_free(data->name);
+	g_free(data);
+}
+
+static int name_data_add(DBusConnection *connection, const char *name,
+						GDBusWatchFunction connect,
+						GDBusWatchFunction disconnect,
+						void *user_data, guint id)
+{
+	int first = 1;
+	struct name_data *data = NULL;
+	struct name_callback *cb = NULL;
+
+	cb = g_new(struct name_callback, 1);
+
+	cb->conn_func = connect;
+	cb->disc_func = disconnect;
+	cb->user_data = user_data;
+	cb->id = id;
+
+	data = name_data_find(connection, name);
+	if (data) {
+		first = 0;
+		goto done;
+	}
+
+	data = g_new0(struct name_data, 1);
+
+	data->connection = connection;
+	data->name = g_strdup(name);
+
+	name_listeners = g_slist_append(name_listeners, data);
+
+done:
+	data->callbacks = g_slist_append(data->callbacks, cb);
+	return first;
+}
+
+static void name_data_remove(DBusConnection *connection,
+					const char *name, guint id)
+{
+	struct name_data *data;
+	struct name_callback *cb = NULL;
+
+	data = name_data_find(connection, name);
+	if (!data)
+		return;
+
+	cb = name_callback_find(data->callbacks, id);
+	if (cb) {
+		data->callbacks = g_slist_remove(data->callbacks, cb);
+		g_free(cb);
+	}
+
+	if (data->callbacks)
+		return;
+
+	name_listeners = g_slist_remove(name_listeners, data);
+	name_data_free(data);
+
+	/* Remove filter if there are no listeners left for the connection */
+	data = name_data_find(connection, NULL);
+	if (!data)
+		dbus_connection_remove_filter(connection,
+						name_exit_filter,
+						NULL);
+}
+
+static gboolean add_match(DBusConnection *connection, const char *name)
+{
+	DBusError err;
+	char match_string[128];
+
+	snprintf(match_string, sizeof(match_string),
+			"interface=%s,member=NameOwnerChanged,arg0=%s",
+			DBUS_INTERFACE_DBUS, name);
+
+	dbus_error_init(&err);
+
+	dbus_bus_add_match(connection, match_string, &err);
+
+	if (dbus_error_is_set(&err)) {
+		error("Adding match rule \"%s\" failed: %s", match_string,
+				err.message);
+		dbus_error_free(&err);
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+static gboolean remove_match(DBusConnection *connection, const char *name)
+{
+	DBusError err;
+	char match_string[128];
+
+	snprintf(match_string, sizeof(match_string),
+			"interface=%s,member=NameOwnerChanged,arg0=%s",
+			DBUS_INTERFACE_DBUS, name);
+
+	dbus_error_init(&err);
+
+	dbus_bus_remove_match(connection, match_string, &err);
+
+	if (dbus_error_is_set(&err)) {
+		error("Removing owner match rule for %s failed: %s",
+				name, err.message);
+		dbus_error_free(&err);
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+static DBusHandlerResult name_exit_filter(DBusConnection *connection,
+					DBusMessage *message, void *user_data)
+{
+	GSList *l;
+	struct name_data *data;
+	char *name, *old, *new;
+	int keep = 0;
+
+	if (!dbus_message_is_signal(message, DBUS_INTERFACE_DBUS,
+							"NameOwnerChanged"))
+		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+
+	if (!dbus_message_get_args(message, NULL,
+				DBUS_TYPE_STRING, &name,
+				DBUS_TYPE_STRING, &old,
+				DBUS_TYPE_STRING, &new,
+				DBUS_TYPE_INVALID)) {
+		error("Invalid arguments for NameOwnerChanged signal");
+		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+	}
+
+	data = name_data_find(connection, name);
+	if (!data) {
+		error("Got NameOwnerChanged signal for %s which has no listeners", name);
+		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+	}
+
+	for (l = data->callbacks; l != NULL; l = l->next) {
+		struct name_callback *cb = l->data;
+		if (*new == '\0') {
+			if (cb->disc_func)
+				cb->disc_func(connection, cb->user_data);
+		} else {
+			if (cb->conn_func)
+				cb->conn_func(connection, cb->user_data);
+		}
+		if (cb->conn_func && cb->disc_func)
+			keep = 1;
+	}
+
+	if (keep)
+		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+
+	name_listeners = g_slist_remove(name_listeners, data);
+	name_data_free(data);
+
+	/* Remove filter if there no listener left for the connection */
+	data = name_data_find(connection, NULL);
+	if (!data)
+		dbus_connection_remove_filter(connection, name_exit_filter,
+						NULL);
+
+	remove_match(connection, name);
+
+	return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+}
+
+guint g_dbus_add_service_watch(DBusConnection *connection, const char *name,
+				GDBusWatchFunction connect,
+				GDBusWatchFunction disconnect,
+				void *user_data, GDBusDestroyFunction destroy)
+{
+	int first;
+
+	if (!name_data_find(connection, NULL)) {
+		if (!dbus_connection_add_filter(connection,
+					name_exit_filter, NULL, NULL)) {
+			error("dbus_connection_add_filter() failed");
+			return 0;
+		}
+	}
+
+	listener_id++;
+	first = name_data_add(connection, name, connect, disconnect,
+						user_data, listener_id);
+	/* The filter is already added if this is not the first callback
+	 * registration for the name */
+	if (!first)
+		return listener_id;
+
+	if (name) {
+		debug("name_listener_add(%s)", name);
+
+		if (!add_match(connection, name)) {
+			name_data_remove(connection, name, listener_id);
+			return 0;
+		}
+	}
+
+	return listener_id;
+}
+
+guint g_dbus_add_disconnect_watch(DBusConnection *connection, const char *name,
+				GDBusWatchFunction func,
+				void *user_data, GDBusDestroyFunction destroy)
+{
+	return g_dbus_add_service_watch(connection, name, NULL, func,
+							user_data, destroy);
+}
+
+guint g_dbus_add_signal_watch(DBusConnection *connection,
+				const char *rule, GDBusSignalFunction function,
+				void *user_data, GDBusDestroyFunction destroy)
+{
+	return 0;
+}
+
+gboolean g_dbus_remove_watch(DBusConnection *connection, guint id)
+{
+	struct name_data *data;
+	struct name_callback *cb;
+	GSList *ldata, *lcb;
+
+	if (id == 0)
+		return FALSE;
+
+	for (ldata = name_listeners; ldata; ldata = ldata->next) {
+		data = ldata->data;
+		for (lcb = data->callbacks; lcb; lcb = lcb->next) {
+			cb = lcb->data;
+			if (cb->id == id)
+				goto remove;
+		}
+	}
+
+	return FALSE;
+
+remove:
+	data->callbacks = g_slist_remove(data->callbacks, cb);
+	g_free(cb);
+
+	/* Don't remove the filter if other callbacks exist */
+	if (data->callbacks)
+		return TRUE;
+
+	if (data->name) {
+		if (!remove_match(data->connection, data->name))
+			return FALSE;
+	}
+
+	name_listeners = g_slist_remove(name_listeners, data);
+	name_data_free(data);
+
+	/* Remove filter if there are no listeners left for the connection */
+	data = name_data_find(connection, NULL);
+	if (!data)
+		dbus_connection_remove_filter(connection, name_exit_filter,
+						NULL);
+
+	return TRUE;
+}
+
+void g_dbus_remove_all_watches(DBusConnection *connection)
+{
+	struct name_data *data;
+
+	while ((data = name_data_find(connection, NULL))) {
+		name_listeners = g_slist_remove(name_listeners, data);
+		name_data_call_and_free(data);
+	}
+
+	dbus_connection_remove_filter(connection, name_exit_filter, NULL);
+}