[Telepathy-commits] [telepathy-glib/master] TpDBusDaemon: add internal _tp_dbus_daemon_request_name() method

[Simon McVittie]

To avoid unnecessarily broad signal matching (fd.o #14183) we should
avoid instantiating a DBusGProxy for the dbus-daemon (since that
will probably always have to bind to signals from the whole
interface for backwards compatibility). We can reduce the need to
instantiate such a DBusGProxy by replicating basic functionality.

This is only internal API for now, but it could be promoted to
public API later.
---
 telepathy-glib/dbus-internal.h |    3 ++
 telepathy-glib/dbus.c          |   74 +++++++++++++++++++++++++++++++++++++++-
 2 files changed, 76 insertions(+), 1 deletions(-)

diff --git a/telepathy-glib/dbus-internal.h b/telepathy-glib/dbus-internal.h
index 8465c6f..1e5f53d 100644
--- a/telepathy-glib/dbus-internal.h
+++ b/telepathy-glib/dbus-internal.h
@@ -29,6 +29,9 @@ G_BEGIN_DECLS
 gboolean _tp_dbus_daemon_get_name_owner (TpDBusDaemon *self, gint timeout_ms,
     const gchar *well_known_name, gchar **unique_name, GError **error);
 
+gboolean _tp_dbus_daemon_request_name (TpDBusDaemon *self,
+    const gchar *well_known_name, gboolean idempotent, GError **error);
+
 void _tp_register_dbus_glib_marshallers (void);
 
 G_END_DECLS
diff --git a/telepathy-glib/dbus.c b/telepathy-glib/dbus.c
index 88ec078..649b51a 100644
--- a/telepathy-glib/dbus.c
+++ b/telepathy-glib/dbus.c
@@ -57,7 +57,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <dbus/dbus-shared.h>
+#include <dbus/dbus.h>
+#include <dbus/dbus-glib-lowlevel.h>
 
 #include <telepathy-glib/errors.h>
 #include <telepathy-glib/interfaces.h>
@@ -984,6 +985,77 @@ _tp_dbus_daemon_get_name_owner (TpDBusDaemon *self,
       G_TYPE_INVALID);
 }
 
+/**
+ * _tp_dbus_daemon_request_name:
+ * @self: a TpDBusDaemon
+ * @well_known_name: a well-known name to acquire
+ * @idempotent: whether to consider it to be a success if this process
+ *              already owns the name
+ * @error: used to raise an error if %FALSE is returned
+ *
+ * Claim the given well-known name without queueing, allowing replacement
+ * or replacing an existing name-owner.
+ *
+ * For internal use by TpBaseConnection, TpBaseConnectionManager.
+ */
+gboolean
+_tp_dbus_daemon_request_name (TpDBusDaemon *self,
+                              const gchar *well_known_name,
+                              gboolean idempotent,
+                              GError **error)
+{
+  TpProxy *as_proxy = (TpProxy *) self;
+  DBusGConnection *gconn = as_proxy->dbus_connection;
+  DBusConnection *dbc = dbus_g_connection_get_connection (gconn);
+  DBusError dbus_error;
+  int result;
+
+  g_return_val_if_fail (TP_IS_DBUS_DAEMON (self), FALSE);
+  g_return_val_if_fail (tp_dbus_check_valid_bus_name (well_known_name,
+        TP_DBUS_NAME_TYPE_WELL_KNOWN, error), FALSE);
+
+  dbus_error_init (&dbus_error);
+  result = dbus_bus_request_name (dbc, well_known_name,
+      DBUS_NAME_FLAG_DO_NOT_QUEUE, &dbus_error);
+
+  switch (result)
+    {
+    case DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER:
+      return TRUE;
+
+    case DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER:
+      if (idempotent)
+        {
+          return TRUE;
+        }
+      else
+        {
+          g_set_error (error, TP_ERRORS, TP_ERROR_NOT_AVAILABLE,
+              "Name '%s' already in use by this process", well_known_name);
+          return FALSE;
+        }
+
+    case DBUS_REQUEST_NAME_REPLY_EXISTS:
+    case DBUS_REQUEST_NAME_REPLY_IN_QUEUE:
+      /* the latter shouldn't actually happen since we said DO_NOT_QUEUE */
+      g_set_error (error, TP_ERRORS, TP_ERROR_NOT_AVAILABLE,
+          "Name '%s' already in use by another process", well_known_name);
+      return FALSE;
+
+    case -1:
+      g_set_error (error, TP_ERRORS, TP_ERROR_NOT_AVAILABLE,
+          "%s: %s", dbus_error.name, dbus_error.message);
+      dbus_error_free (&dbus_error);
+      return FALSE;
+
+    default:
+      g_set_error (error, TP_ERRORS, TP_ERROR_NOT_AVAILABLE,
+          "RequestName('%s') returned %d and I don't know what that means",
+          well_known_name, result);
+      return FALSE;
+    }
+}
+
 static GObject *
 tp_dbus_daemon_constructor (GType type,
                             guint n_params,
-- 
1.5.6.5