start dbus service by its name if it's not up.

we still guess it was up and try to get its name, if not possible then
try to start it and then get is name.

another way to do it would be to always request start and just then
get its name and just then start to listen to NameOwnerChanged. But
the current way is good enough and should save some roundtrips for
good cases (server is up).



SVN revision: 40955

legacy/ethumb/src/lib/client/Ethumb_Client.c

@@ -58,6 +58,7 @@ struct _Ethumb_Client
    E_DBus_Signal_Handler *name_owner_changed_handler;
    E_DBus_Signal_Handler *generated_signal;
    DBusPendingCall *pending_get_name_owner;
+   DBusPendingCall *pending_start_service_by_name;
    const char *unique_name;
    DBusPendingCall *pending_new;
    ec_connect_callback_t connect_cb;
@@ -73,6 +74,7 @@ struct _Ethumb_Client
 
    Eina_Bool ethumb_dirty : 1;
    Eina_Bool connected : 1;
+   Eina_Bool server_started : 1;
 };
 
 struct _ethumb_pending_add
@@ -119,6 +121,7 @@ static const char fdo_path[] = "/org/freedesktop/DBus";
 static int _initcount = 0;
 
 static void _ethumb_client_generated_cb(void *data, DBusMessage *msg);
+static void _ethumb_client_get_name_owner(void *data, DBusMessage *msg, DBusError *err);
 
 static inline bool
 __dbus_callback_check_and_init(const char *file, int line, const char *function, DBusMessage *msg, DBusMessageIter *itr, DBusError *err)
@@ -265,6 +268,77 @@ _ethumb_client_call_new(Ethumb_Client *client)
    dbus_message_unref(msg);
 }
 
+static void
+_ethumb_client_start_server_cb(void *data, DBusMessage *msg, DBusError *err)
+{
+   Ethumb_Client *client = data;
+   DBusMessageIter iter;
+   unsigned int ret;
+   int t;
+
+   client->pending_start_service_by_name = NULL;
+
+   if (!_dbus_callback_check_and_init(msg, &iter, err))
+     goto error;
+
+   t = dbus_message_iter_get_arg_type(&iter);
+   if (!_dbus_iter_type_check(t, DBUS_TYPE_UINT32))
+     goto error;
+
+   dbus_message_iter_get_basic(&iter, &ret);
+   if ((ret != 1) && (ret != 2))
+     {
+	ERR("Error starting Ethumbd DBus service by its name: retcode %u\n",
+	    ret);
+	goto error;
+     }
+
+   client->server_started = 1;
+   DBG("Ethumbd DBus service started successfully (%d), now request its name\n",
+       ret);
+
+   if (client->pending_get_name_owner)
+     {
+	DBG("already requesting name owner, cancel and try again\n");
+	dbus_pending_call_cancel(client->pending_get_name_owner);
+     }
+
+   client->pending_get_name_owner = e_dbus_get_name_owner
+     (client->conn, _ethumb_dbus_bus_name, _ethumb_client_get_name_owner,
+      client);
+   if (!client->pending_get_name_owner)
+     {
+	ERR("could not create a get_name_owner request.\n");
+	goto error;
+     }
+
+   return;
+
+ error:
+   ERR("failed to start Ethumbd DBus service by its name.\n");
+   client->connect_cb(client, 0, client->connect_cb_data);
+}
+
+static void
+_ethumb_client_start_server(Ethumb_Client *client)
+{
+   if (client->pending_start_service_by_name)
+     {
+	DBG("already pending start service by name.\n");
+	return;
+     }
+
+   client->server_started = 0;
+   client->pending_start_service_by_name = e_dbus_start_service_by_name
+     (client->conn, _ethumb_dbus_bus_name, 0, _ethumb_client_start_server_cb,
+      client);
+   if (!client->pending_start_service_by_name)
+     {
+	ERR("could not start service by name!\n");
+	client->connect_cb(client, 0, client->connect_cb_data);
+     }
+}
+
 static void
 _ethumb_client_get_name_owner(void *data, DBusMessage *msg, DBusError *err)
 {
@@ -275,6 +349,13 @@ _ethumb_client_get_name_owner(void *data, DBusMessage *msg, DBusError *err)
 
    client->pending_get_name_owner = NULL;
 
+   if (dbus_error_is_set(err) && (!client->server_started))
+     {
+	DBG("could not find server (%s), try to start it...\n", err->message);
+	_ethumb_client_start_server(client);
+	return;
+     }
+
    if (!_dbus_callback_check_and_init(msg, &iter, err))
      goto error;
 
@@ -420,6 +501,9 @@ end_connection:
    if (client->pending_get_name_owner)
      dbus_pending_call_cancel(client->pending_get_name_owner);
 
+   if (client->pending_start_service_by_name)
+     dbus_pending_call_cancel(client->pending_start_service_by_name);
+
    ethumb_free(client->ethumb);
 
    e_dbus_signal_handler_del(client->conn, client->name_owner_changed_handler);