[pygobject] GObject.Value: add a static helper for fetching the GType

[Christoph Reiter <creiter src gnome org>]

commit 48f80f8b763d84294c73f428bf7ede39cef57027
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Fri Jan 18 20:07:17 2019 +0100

    GObject.Value: add a static helper for fetching the GType
    
    The field marshalling code is slow and doesn't do any caching at all
    which in turn makes accessing Value.g_type slow.
    
    Add a static helper function for fetching the GType and use that instead.
    This reduced the time for creating a GValue + setting it by ~30%

 gi/gimodule.c           |  2 ++
 gi/overrides/GObject.py | 16 +++++++++++-----
 gi/pygi-value.c         | 16 ++++++++++++++++
 gi/pygi-value.h         |  1 +
 4 files changed, 30 insertions(+), 5 deletions(-)
---
diff --git a/gi/gimodule.c b/gi/gimodule.c
index 7ff9b0eb..2be5e478 100644
--- a/gi/gimodule.c
+++ b/gi/gimodule.c
@@ -2291,6 +2291,8 @@ static PyMethodDef _gi_functions[] = {
       (PyCFunction)pyg__install_metaclass, METH_O },
     { "_gvalue_get",
       (PyCFunction)pyg__gvalue_get, METH_O },
+    { "_gvalue_get_type",
+      (PyCFunction)pyg__gvalue_get_type, METH_O },
     { "_gvalue_set",
       (PyCFunction)pyg__gvalue_set, METH_VARARGS },
     { NULL, NULL, 0 }
diff --git a/gi/overrides/GObject.py b/gi/overrides/GObject.py
index 4cc08a9a..04b5be65 100644
--- a/gi/overrides/GObject.py
+++ b/gi/overrides/GObject.py
@@ -209,8 +209,14 @@ class Value(GObjectModule.Value):
             if py_value is not None:
                 self.set_value(py_value)
 
+    @property
+    def __g_type(self):
+        # XXX: This is the same as self.g_type, but the field marshalling
+        # code is currently very slow.
+        return _gi._gvalue_get_type(self)
+
     def set_boxed(self, boxed):
-        if not self.g_type.is_a(TYPE_BOXED):
+        if not self.__g_type.is_a(TYPE_BOXED):
             warnings.warn('Calling set_boxed() on a non-boxed type deprecated',
                           PyGIDeprecationWarning, stacklevel=2)
         # Workaround the introspection marshalers inability to know
@@ -219,13 +225,13 @@ class Value(GObjectModule.Value):
         _gi._gvalue_set(self, boxed)
 
     def get_boxed(self):
-        if not self.g_type.is_a(TYPE_BOXED):
+        if not self.__g_type.is_a(TYPE_BOXED):
             warnings.warn('Calling get_boxed() on a non-boxed type deprecated',
                           PyGIDeprecationWarning, stacklevel=2)
         return _gi._gvalue_get(self)
 
     def set_value(self, py_value):
-        gtype = self.g_type
+        gtype = self.__g_type
 
         if gtype == _gi.TYPE_INVALID:
             raise TypeError("GObject.Value needs to be initialized first")
@@ -288,7 +294,7 @@ class Value(GObjectModule.Value):
             _gi._gvalue_set(self, py_value)
 
     def get_value(self):
-        gtype = self.g_type
+        gtype = self.__g_type
 
         if gtype == TYPE_BOOLEAN:
             return self.get_boolean()
@@ -340,7 +346,7 @@ class Value(GObjectModule.Value):
             return _gi._gvalue_get(self)
 
     def __repr__(self):
-        return '<Value (%s) %s>' % (self.g_type.name, self.get_value())
+        return '<Value (%s) %s>' % (self.__g_type.name, self.get_value())
 
 
 Value = override(Value)
diff --git a/gi/pygi-value.c b/gi/pygi-value.c
index 93669345..8376231e 100644
--- a/gi/pygi-value.c
+++ b/gi/pygi-value.c
@@ -886,6 +886,22 @@ pyg__gvalue_get(PyObject *module, PyObject *pygvalue)
                                   /*copy_boxed=*/ TRUE);
 }
 
+PyObject *
+pyg__gvalue_get_type(PyObject *module, PyObject *pygvalue)
+{
+    GValue *value;
+    GType type;
+
+    if (!pyg_boxed_check (pygvalue, G_TYPE_VALUE)) {
+        PyErr_SetString (PyExc_TypeError, "Expected GValue argument.");
+        return NULL;
+    }
+
+    value = pyg_boxed_get (pygvalue, GValue);
+    type = G_VALUE_TYPE (value);
+    return pyg_type_wrapper_new (type);
+}
+
 PyObject *
 pyg__gvalue_set(PyObject *module, PyObject *args)
 {
diff --git a/gi/pygi-value.h b/gi/pygi-value.h
index 6450112d..5778a22c 100644
--- a/gi/pygi-value.h
+++ b/gi/pygi-value.h
@@ -45,6 +45,7 @@ PyObject *pygi_value_to_py_basic_type      (const GValue *value,
 
 PyObject *pyg__gvalue_get(PyObject *module, PyObject *pygvalue);
 PyObject *pyg__gvalue_set(PyObject *module, PyObject *args);
+PyObject *pyg__gvalue_get_type(PyObject *module, PyObject *pygvalue);
 
 G_END_DECLS