GDBus: add 'monitor' verb to gdbus(1)

This uncovered a bug in name watching if the name wasn't activatable.

Also provoked the need for on_connection variants of g_bus_watch_name
(added g_bus_watch_proxy's variant as well).

docs/reference/gio/gdbus.xml

@@ -23,6 +23,19 @@
     <arg choice="plain">--dest <replaceable>bus_name</replaceable></arg>
     <arg choice="plain">--object-path <replaceable>/path/to/object</replaceable></arg>
   </cmdsynopsis>
+  <cmdsynopsis>
+    <command>gdbus</command>
+    <arg choice="plain">monitor</arg>
+    <group>
+      <arg choice="plain">--system</arg>
+      <arg choice="plain">--session</arg>
+      <arg choice="plain">--address <replaceable>address</replaceable></arg>
+    </group>
+    <arg choice="plain">--dest <replaceable>bus_name</replaceable></arg>
+    <group>
+      <arg choice="plain">--object-path <replaceable>/path/to/object</replaceable></arg>
+    </group>
+  </cmdsynopsis>
   <cmdsynopsis>
     <command>gdbus</command>
     <arg choice="plain">call</arg>
@@ -60,6 +73,13 @@
           <literal>org.freedesktop.DBus.Introspectable</literal> interface.
         </para></listitem>
       </varlistentry>
+      <varlistentry>
+        <term><option>monitor</option></term>
+        <listitem><para>
+          Monitors one or all objects owned by the owned of
+          <replaceable>bus_name</replaceable>.
+        </para></listitem>
+      </varlistentry>
       <varlistentry>
         <term><option>call</option></term>
         <listitem><para>
@@ -189,6 +209,29 @@ $ gdbus call --session \
              5000
 (uint32 12,)
 </programlisting>
+<para>
+  Monitoring all objects on a service:
+</para>
+<programlisting>
+$ gdbus monitor --system --dest org.freedesktop.ConsoleKit
+Monitoring signals from all objects owned by org.freedesktop.ConsoleKit
+The name org.freedesktop.ConsoleKit is owned by :1.15
+/org/freedesktop/ConsoleKit/Session2: org.freedesktop.ConsoleKit.Session.ActiveChanged (false,)
+/org/freedesktop/ConsoleKit/Seat1: org.freedesktop.ConsoleKit.Seat.ActiveSessionChanged ('',)
+/org/freedesktop/ConsoleKit/Session2: org.freedesktop.ConsoleKit.Session.ActiveChanged (true,)
+/org/freedesktop/ConsoleKit/Seat1: org.freedesktop.ConsoleKit.Seat.ActiveSessionChanged ('/org/freedesktop/ConsoleKit/Session2',)
+</programlisting>
+<para>
+  Monitoring a single object on a service:
+</para>
+<programlisting>
+$ gdbus monitor --system --dest org.freedesktop.ConsoleKit --object-path /org/freedesktop/ConsoleKit/Session2
+Monitoring signals on object /org/freedesktop/ConsoleKit/Session2 owned by org.freedesktop.ConsoleKit
+The name org.freedesktop.ConsoleKit is owned by :1.15
+/org/freedesktop/ConsoleKit/Session2: org.freedesktop.ConsoleKit.Session.ActiveChanged (false,)
+/org/freedesktop/ConsoleKit/Session2: org.freedesktop.ConsoleKit.Session.ActiveChanged (true,)
+</programlisting>
+
 </refsect1>
 
 <refsect1>

docs/reference/gio/gio-sections.txt

@@ -2446,6 +2446,7 @@ GBusNameAppearedCallback
 GBusNameVanishedCallback
 GBusNameWatcherFlags
 g_bus_watch_name
+g_bus_watch_name_on_connection
 g_bus_unwatch_name
 </SECTION>
 
@@ -2454,6 +2455,7 @@ g_bus_unwatch_name
 GBusProxyAppearedCallback
 GBusProxyVanishedCallback
 g_bus_watch_proxy
+g_bus_watch_proxy_on_connection
 g_bus_unwatch_proxy
 </SECTION>
 

gio/gdbus-tool.c

@@ -92,6 +92,7 @@ usage (gint *argc, gchar **argv[], gboolean use_stdout)
   s = g_strdup_printf (_("Commands:\n"
                          "  help         Shows this information\n"
                          "  introspect   Introspect a remote object\n"
+                         "  monitor      Monitor a remote object\n"
                          "  call         Invoke a method on a remote object\n"
                          "\n"
                          "Use \"%s COMMAND --help\" to get help on each command.\n"),
@@ -1380,6 +1381,246 @@ handle_introspect (gint        *argc,
 
 /* ---------------------------------------------------------------------------------------------------- */
 
+static gchar *opt_monitor_dest = NULL;
+static gchar *opt_monitor_object_path = NULL;
+
+static guint monitor_filter_id = 0;
+
+static void
+monitor_signal_cb (GDBusConnection *connection,
+                   const gchar     *sender_name,
+                   const gchar     *object_path,
+                   const gchar     *interface_name,
+                   const gchar     *signal_name,
+                   GVariant        *parameters,
+                   gpointer         user_data)
+{
+  gchar *s;
+  s = g_variant_print (parameters, TRUE);
+  g_print ("%s: %s.%s %s\n",
+           object_path,
+           interface_name,
+           signal_name,
+           s);
+  g_free (s);
+}
+
+static void
+monitor_on_name_appeared (GDBusConnection *connection,
+                          const gchar *name,
+                          const gchar *name_owner,
+                          gpointer user_data)
+{
+  g_print ("The name %s is owned by %s\n", name, name_owner);
+  g_assert (monitor_filter_id == 0);
+  monitor_filter_id = g_dbus_connection_signal_subscribe (connection,
+                                                          name_owner,
+                                                          NULL,  /* any interface */
+                                                          NULL,  /* any member */
+                                                          opt_monitor_object_path,
+                                                          NULL,  /* arg0 */
+                                                          monitor_signal_cb,
+                                                          NULL,  /* user_data */
+                                                          NULL); /* user_data destroy notify */
+}
+
+static void
+monitor_on_name_vanished (GDBusConnection *connection,
+                          const gchar *name,
+                          gpointer user_data)
+{
+  g_print ("The name %s does not have an owner\n", name);
+
+  if (monitor_filter_id != 0)
+    {
+      g_dbus_connection_signal_unsubscribe (connection, monitor_filter_id);
+      monitor_filter_id = 0;
+    }
+}
+
+static const GOptionEntry monitor_entries[] =
+{
+  { "dest", 'd', 0, G_OPTION_ARG_STRING, &opt_monitor_dest, N_("Destination name to monitor"), NULL},
+  { "object-path", 'o', 0, G_OPTION_ARG_STRING, &opt_monitor_object_path, N_("Object path to monitor"), NULL},
+  { NULL }
+};
+
+static gboolean
+handle_monitor (gint        *argc,
+                gchar      **argv[],
+                gboolean     request_completion,
+                const gchar *completion_cur,
+                const gchar *completion_prev)
+{
+  gint ret;
+  GOptionContext *o;
+  gchar *s;
+  GError *error;
+  GDBusConnection *c;
+  GVariant *result;
+  GDBusNodeInfo *node;
+  gboolean complete_names;
+  gboolean complete_paths;
+  GMainLoop *loop;
+
+  ret = FALSE;
+  c = NULL;
+  node = NULL;
+  result = NULL;
+
+  modify_argv0_for_command (argc, argv, "monitor");
+
+  o = g_option_context_new (NULL);
+  if (request_completion)
+    g_option_context_set_ignore_unknown_options (o, TRUE);
+  g_option_context_set_help_enabled (o, FALSE);
+  g_option_context_set_summary (o, _("Monitor a remote object."));
+  g_option_context_add_main_entries (o, monitor_entries, NULL /* GETTEXT_PACKAGE*/);
+  g_option_context_add_group (o, connection_get_group ());
+
+  complete_names = FALSE;
+  if (request_completion && *argc > 1 && g_strcmp0 ((*argv)[(*argc)-1], "--dest") == 0)
+    {
+      complete_names = TRUE;
+      remove_arg ((*argc) - 1, argc, argv);
+    }
+
+  complete_paths = FALSE;
+  if (request_completion && *argc > 1 && g_strcmp0 ((*argv)[(*argc)-1], "--object-path") == 0)
+    {
+      complete_paths = TRUE;
+      remove_arg ((*argc) - 1, argc, argv);
+    }
+
+  if (!g_option_context_parse (o, argc, argv, NULL))
+    {
+      if (!request_completion)
+        {
+          s = g_option_context_get_help (o, FALSE, NULL);
+          g_printerr ("%s", s);
+          g_free (s);
+          goto out;
+        }
+    }
+
+  error = NULL;
+  c = connection_get_dbus_connection (&error);
+  if (c == NULL)
+    {
+      if (request_completion)
+        {
+          if (g_strcmp0 (completion_prev, "--address") == 0)
+            {
+              g_print ("unix:\n"
+                       "tcp:\n"
+                       "nonce-tcp:\n");
+            }
+          else
+            {
+              g_print ("--system \n--session \n--address \n");
+            }
+        }
+      else
+        {
+          g_printerr (_("Error connecting: %s\n"), error->message);
+          g_error_free (error);
+        }
+      goto out;
+    }
+
+  if (g_dbus_connection_get_unique_name (c) != NULL)
+    {
+      if (complete_names)
+        {
+          print_names (c, FALSE);
+          goto out;
+        }
+      /* this only makes sense on message bus connections */
+      if (opt_monitor_dest == NULL)
+        {
+          if (request_completion)
+            g_print ("--dest \n");
+          else
+            g_printerr (_("Error: Destination is not specified\n"));
+          goto out;
+        }
+      if (request_completion && g_strcmp0 ("--dest", completion_prev) == 0)
+        {
+          print_names (c, g_str_has_prefix (opt_monitor_dest, ":"));
+          goto out;
+        }
+    }
+  if (complete_paths)
+    {
+      print_paths (c, opt_monitor_dest, "/");
+      goto out;
+    }
+  if (opt_monitor_object_path == NULL)
+    {
+      if (request_completion)
+        {
+          g_print ("--object-path \n");
+          goto out;
+        }
+      /* it's fine to not have an object path */
+    }
+  if (request_completion && g_strcmp0 ("--object-path", completion_prev) == 0)
+    {
+      gchar *p;
+      s = g_strdup (opt_monitor_object_path);
+      p = strrchr (s, '/');
+      if (p != NULL)
+        {
+          if (p == s)
+            p++;
+          *p = '\0';
+        }
+      print_paths (c, opt_monitor_dest, s);
+      g_free (s);
+      goto out;
+    }
+  if (!request_completion && (opt_monitor_object_path != NULL && !g_variant_is_object_path (opt_monitor_object_path)))
+    {
+      g_printerr (_("Error: %s is not a valid object path\n"), opt_monitor_object_path);
+      goto out;
+    }
+
+  /* All done with completion now */
+  if (request_completion)
+    goto out;
+
+  if (opt_monitor_object_path != NULL)
+    g_print ("Monitoring signals on object %s owned by %s\n", opt_monitor_object_path, opt_monitor_dest);
+  else
+    g_print ("Monitoring signals from all objects owned by %s\n", opt_monitor_dest);
+
+  loop = g_main_loop_new (NULL, FALSE);
+  g_bus_watch_name_on_connection (c,
+                                  opt_monitor_dest,
+                                  G_BUS_NAME_WATCHER_FLAGS_AUTO_START,
+                                  monitor_on_name_appeared,
+                                  monitor_on_name_vanished,
+                                  NULL,
+                                  NULL);
+
+  g_main_loop_run (loop);
+  g_main_loop_unref (loop);
+
+  ret = TRUE;
+
+ out:
+  if (node != NULL)
+    g_dbus_node_info_unref (node);
+  if (result != NULL)
+    g_variant_unref (result);
+  if (c != NULL)
+    g_object_unref (c);
+  g_option_context_free (o);
+  return ret;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
 static gchar *
 pick_word_at (const gchar  *s,
               gint          cursor,
@@ -1476,6 +1717,16 @@ main (gint argc, gchar *argv[])
         ret = 0;
       goto out;
     }
+  else if (g_strcmp0 (command, "monitor") == 0)
+    {
+      if (handle_monitor (&argc,
+                          &argv,
+                          request_completion,
+                          completion_cur,
+                          completion_prev))
+        ret = 0;
+      goto out;
+    }
   else if (g_strcmp0 (command, "complete") == 0 && argc == 4 && !request_completion)
     {
       const gchar *completion_line;
@@ -1545,7 +1796,7 @@ main (gint argc, gchar *argv[])
     {
       if (request_completion)
         {
-          g_print ("help \ncall \nintrospect \n");
+          g_print ("help \ncall \nintrospect \nmonitor \n");
           ret = 0;
           goto out;
         }

gio/gdbusnamewatching.c

@@ -417,10 +417,11 @@ start_service_by_name_cb (GObject      *source_object,
        *   org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.Epiphany2
        *   was not provided by any .service files
        *
-       * so just report vanished.
+       * This doesn't mean that the name doesn't have an owner, just
+       * that it's not provided by a .service file. So proceed to
+       * invoke GetNameOwner().
        */
-      call_vanished_handler (client, FALSE);
+      invoke_get_name_owner (client);
-      client->initialized = TRUE;
     }
 
   if (result != NULL)
@@ -586,6 +587,68 @@ g_bus_watch_name (GBusType                  bus_type,
   return client->id;
 }
 
+/**
+ * g_bus_watch_name_on_connection:
+ * @connection: A #GDBusConnection that is not closed.
+ * @name: The name (well-known or unique) to watch.
+ * @flags: Flags from the #GBusNameWatcherFlags enumeration.
+ * @name_appeared_handler: Handler to invoke when @name is known to exist or %NULL.
+ * @name_vanished_handler: Handler to invoke when @name is known to not exist or %NULL.
+ * @user_data: User data to pass to handlers.
+ * @user_data_free_func: Function for freeing @user_data or %NULL.
+ *
+ * Like g_bus_watch_name() but takes a #GDBusConnection instead of a
+ * #GBusType.
+ *
+ * Returns: An identifier (never 0) that an be used with
+ * g_bus_unwatch_name() to stop watching the name.
+ *
+ * Since: 2.26
+ */
+guint g_bus_watch_name_on_connection (GDBusConnection          *connection,
+                                      const gchar              *name,
+                                      GBusNameWatcherFlags      flags,
+                                      GBusNameAppearedCallback  name_appeared_handler,
+                                      GBusNameVanishedCallback  name_vanished_handler,
+                                      gpointer                  user_data,
+                                      GDestroyNotify            user_data_free_func)
+{
+  Client *client;
+
+  g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), 0);
+  g_return_val_if_fail (g_dbus_is_name (name), 0);
+
+  G_LOCK (lock);
+
+  client = g_new0 (Client, 1);
+  client->ref_count = 1;
+  client->id = next_global_id++; /* TODO: uh oh, handle overflow */
+  client->name = g_strdup (name);
+  client->flags = flags;
+  client->name_appeared_handler = name_appeared_handler;
+  client->name_vanished_handler = name_vanished_handler;
+  client->user_data = user_data;
+  client->user_data_free_func = user_data_free_func;
+  client->main_context = g_main_context_get_thread_default ();
+  if (client->main_context != NULL)
+    g_main_context_ref (client->main_context);
+
+  if (map_id_to_client == NULL)
+    {
+      map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
+    }
+  g_hash_table_insert (map_id_to_client,
+                       GUINT_TO_POINTER (client->id),
+                       client);
+
+  client->connection = g_object_ref (connection);
+  G_UNLOCK (lock);
+
+  has_connection (client);
+
+  return client->id;
+}
+
 /**
  * g_bus_unwatch_name:
  * @watcher_id: An identifier obtained from g_bus_watch_name()

gio/gdbusnamewatching.h

@@ -65,6 +65,13 @@ guint g_bus_watch_name   (GBusType                  bus_type,
                                       GBusNameVanishedCallback  name_vanished_handler,
                                       gpointer                  user_data,
                                       GDestroyNotify            user_data_free_func);
+guint g_bus_watch_name_on_connection (GDBusConnection          *connection,
+                                      const gchar              *name,
+                                      GBusNameWatcherFlags      flags,
+                                      GBusNameAppearedCallback  name_appeared_handler,
+                                      GBusNameVanishedCallback  name_vanished_handler,
+                                      gpointer                  user_data,
+                                      GDestroyNotify            user_data_free_func);
 void  g_bus_unwatch_name             (guint                     watcher_id);
 
 G_END_DECLS

gio/gdbusproxywatching.c

@@ -25,6 +25,7 @@
 #include <stdlib.h>
 
 #include "gdbusutils.h"
+#include "gdbusconnection.h"
 #include "gdbusnamewatching.h"
 #include "gdbusproxywatching.h"
 #include "gdbuserror.h"
@@ -362,6 +363,91 @@ g_bus_watch_proxy (GBusType                   bus_type,
   return client->id;
 }
 
+/**
+ * g_bus_watch_proxy_on_connection:
+ * @connection: A #GDBusConnection that is not closed.
+ * @name: The name (well-known or unique) to watch.
+ * @flags: Flags from the #GBusNameWatcherFlags enumeration.
+ * @object_path: The object path of the remote object to watch.
+ * @interface_name: The D-Bus interface name for the proxy.
+ * @interface_type: The #GType for the kind of proxy to create. This must be a #GDBusProxy derived type.
+ * @proxy_flags: Flags from #GDBusProxyFlags to use when constructing the proxy.
+ * @proxy_appeared_handler: Handler to invoke when @name is known to exist and the
+ * requested proxy is available.
+ * @proxy_vanished_handler: Handler to invoke when @name is known to not exist
+ * and the previously created proxy is no longer available.
+ * @user_data: User data to pass to handlers.
+ * @user_data_free_func: Function for freeing @user_data or %NULL.
+ *
+ * Like g_bus_watch_proxy() but takes a #GDBusConnection instead of a
+ * #GBusType.
+ *
+ * Returns: An identifier (never 0) that can be used with
+ * g_bus_unwatch_proxy() to stop watching the remote object.
+ *
+ * Since: 2.26
+ */
+guint
+g_bus_watch_proxy_on_connection (GDBusConnection           *connection,
+                                 const gchar               *name,
+                                 GBusNameWatcherFlags       flags,
+                                 const gchar               *object_path,
+                                 const gchar               *interface_name,
+                                 GType                      interface_type,
+                                 GDBusProxyFlags            proxy_flags,
+                                 GBusProxyAppearedCallback  proxy_appeared_handler,
+                                 GBusProxyVanishedCallback  proxy_vanished_handler,
+                                 gpointer                   user_data,
+                                 GDestroyNotify             user_data_free_func)
+{
+  Client *client;
+
+  g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), 0);
+  g_return_val_if_fail (g_dbus_is_name (name), 0);
+  g_return_val_if_fail (g_variant_is_object_path (object_path), 0);
+  g_return_val_if_fail (g_dbus_is_interface_name (interface_name), 0);
+  g_return_val_if_fail (g_type_is_a (interface_type, G_TYPE_DBUS_PROXY), 0);
+
+  G_LOCK (lock);
+
+  client = g_new0 (Client, 1);
+  client->id = next_global_id++; /* TODO: uh oh, handle overflow */
+  client->name = g_strdup (name);
+  client->proxy_appeared_handler = proxy_appeared_handler;
+  client->proxy_vanished_handler = proxy_vanished_handler;
+  client->user_data = user_data;
+  client->user_data_free_func = user_data_free_func;
+  client->main_context = g_main_context_get_thread_default ();
+  if (client->main_context != NULL)
+    g_main_context_ref (client->main_context);
+  client->name_watcher_id = g_bus_watch_name_on_connection (connection,
+                                                            name,
+                                                            flags,
+                                                            on_name_appeared,
+                                                            on_name_vanished,
+                                                            client,
+                                                            NULL);
+
+  client->object_path = g_strdup (object_path);
+  client->interface_name = g_strdup (interface_name);
+  client->interface_type = interface_type;
+  client->proxy_flags = proxy_flags;
+  client->initial_construction = TRUE;
+
+  if (map_id_to_client == NULL)
+    {
+      map_id_to_client = g_hash_table_new (g_direct_hash, g_direct_equal);
+    }
+  g_hash_table_insert (map_id_to_client,
+                       GUINT_TO_POINTER (client->id),
+                       client);
+
+  G_UNLOCK (lock);
+
+  return client->id;
+}
+
+
 /**
  * g_bus_unwatch_proxy:
  * @watcher_id: An identifier obtained from g_bus_watch_proxy()

gio/gdbusproxywatching.h

@@ -74,6 +74,17 @@ guint g_bus_watch_proxy   (GBusType                   bus_type,
                                        GBusProxyVanishedCallback  proxy_vanished_handler,
                                        gpointer                   user_data,
                                        GDestroyNotify             user_data_free_func);
+guint g_bus_watch_proxy_on_connection (GDBusConnection           *connection,
+                                       const gchar               *name,
+                                       GBusNameWatcherFlags       flags,
+                                       const gchar               *object_path,
+                                       const gchar               *interface_name,
+                                       GType                      interface_type,
+                                       GDBusProxyFlags            proxy_flags,
+                                       GBusProxyAppearedCallback  proxy_appeared_handler,
+                                       GBusProxyVanishedCallback  proxy_vanished_handler,
+                                       gpointer                   user_data,
+                                       GDestroyNotify             user_data_free_func);
 void  g_bus_unwatch_proxy             (guint                      watcher_id);
 
 G_END_DECLS

gio/gio.symbols

@@ -1652,6 +1652,7 @@ g_bus_unown_name
 #if IN_HEADER(__G_DBUS_NAME_WATCHING_H__)
 #if IN_FILE(__G_DBUS_NAME_WATCHING_C__)
 g_bus_watch_name
+g_bus_watch_name_on_connection
 g_bus_unwatch_name
 #endif
 #endif
@@ -1683,6 +1684,7 @@ g_dbus_proxy_call_sync
 #if IN_HEADER(__G_DBUS_PROXY_WATCHING_H__)
 #if IN_FILE(__G_DBUS_PROXY_WATCHING_C__)
 g_bus_watch_proxy
+g_bus_watch_proxy_on_connection
 g_bus_unwatch_proxy
 #endif
 #endif