PyEnum: Accelerate item access

With the transition to Python 3.11, access to enum items has
become slower by the replacement of direct item access by
Python properties, involving unnecessarily the use of Python
code.

When we are in charge of Enum item access, we circumvent the
slower property access by using the internal mapping directly.

Task-number: PYSIDE-1735
Change-Id: Iabe045be09df847d9587e9d3f6913e9610f5695e
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
(cherry picked from commit 01e048763a372677c358172a66232f15b09a1021)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 11 insertions, 7 deletions

diff --git a/sources/shiboken6/libshiboken/sbkenum.cpp b/sources/shiboken6/libshiboken/sbkenum.cpp
index 655fd9c58..58dafa497 100644
--- a/sources/shiboken6/libshiboken/sbkenum.cpp
+++ b/sources/shiboken6/libshiboken/sbkenum.cpp
@@ -731,13 +731,17 @@ newItem(PyTypeObject *enumType, long itemValue, const char *itemName)
     if (useOldEnum)
         return newItemOld(enumType, itemValue, itemName);
 
-    if (!itemName) {
-        //PyObject *enumObj = getEnumItemFromValue(enumType, itemValue);
-        PyObject *enumObj = PyObject_CallFunction(reinterpret_cast<PyObject *>(enumType), "i", itemValue);
-        //if (enumObj)
-            return enumObj;
-    }
-    return PyObject_GetAttrString(reinterpret_cast<PyObject *>(enumType), itemName);
+    auto *obEnumType = reinterpret_cast<PyObject *>(enumType);
+    if (!itemName)
+        return PyObject_CallFunction(obEnumType, "i", itemValue);
+
+    static PyObject *const _member_map_ = String::createStaticString("_member_map_");
+    auto *member_map = PyDict_GetItem(enumType->tp_dict, _member_map_);
+    if (!(member_map && PyDict_Check(member_map)))
+        return nullptr;
+    auto *result = PyDict_GetItemString(member_map, itemName);
+    Py_XINCREF(result);
+    return result;
 }
 
 } // namespace Shiboken