[gnome-builder/wip/chergert/multi-process] gdbus: add basic async support to Builder.py overrides

[Christian Hergert <chergert src gnome org>]

commit 58c3ecd8dc4b52537be44e668f7c82b790a7527f
Author: Christian Hergert <chergert redhat com>
Date:   Tue Oct 20 13:04:53 2015 -0700

    gdbus: add basic async support to Builder.py overrides
    
    This allows us to do (async=True) in the decorator so that the callee
    can delay the response to further async work.

 src/Builder.py |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)
---
diff --git a/src/Builder.py b/src/Builder.py
index a6784ef..6485e63 100644
--- a/src/Builder.py
+++ b/src/Builder.py
@@ -41,8 +41,10 @@ class _Gio_DBusMethodInfo:
     in_args = None
     out_signature = None
 
-def DBusMethod(dbus_interface, in_signature=None, out_signature=None):
+def DBusMethod(dbus_interface, in_signature=None, out_signature=None, async=False):
     def decorator(func):
+        func._is_async = async
+
         func._dbus_method = _Gio_DBusMethodInfo()
         func._dbus_method.interface = dbus_interface
         #func._dbus_method.out_signature = '(' + (out_signature or '') + ')'
@@ -52,6 +54,7 @@ def DBusMethod(dbus_interface, in_signature=None, out_signature=None):
         in_signature_list = GLib.Variant.split_signature(in_signature)
         arg_names = inspect.getargspec(func).args
         arg_names.pop(0) # eat "self" argument
+        if async: arg_names.pop(0) # eat "invocation"
         if len(in_signature) != len(arg_names):
             raise TypeError('specified signature %s for method %s does not match length of arguments' % 
(str(in_signature_list), func.func_name))
         for pair in zip(in_signature_list, arg_names):
@@ -135,8 +138,12 @@ class DBusService:
             return
 
         try:
-            ret = getattr(self, method_name)(*parameters.unpack())
-            invocation.return_value(GLib.Variant('(' + info['out_signature'] + ')', (ret,)))
+            func = getattr(self, method_name)
+            if func._is_async:
+                ret = func(invocation, *parameters.unpack())
+            else:
+                ret = func(*parameters.unpack())
+                invocation.return_value(GLib.Variant('(' + info['out_signature'] + ')', (ret,)))
         except Exception as e:
             invocation.return_error_literal(Gio.dbus_error_quark(), 
                                             Gio.DBusError.IO_ERROR,