Rework QJSValue internals

Use a flagged pointer to either store a pointer to a
QV4::Value (from the persistent storage) or a pointer to
a QVariant in QJSValue::d. Like this we don't need to malloc
to create a QJSValue for most use cases.

Significantly reduces the memory consumption of QJSValue and
speeds it up a lot.

Change-Id: I10902cc4b6cc3f43d3f816875dc6c4bbb6b4490f
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/src/qml/jsapi/qjsvalue.h b/src/qml/jsapi/qjsvalue.h
index 4ff86b1edc..19736803c1 100644
--- a/src/qml/jsapi/qjsvalue.h
+++ b/src/qml/jsapi/qjsvalue.h
@@ -49,7 +49,6 @@ struct QMetaObject;
 class QDateTime;
 
 typedef QList<QJSValue> QJSValueList;
-class QJSValuePrivate;
 namespace QV4 {
     struct ExecutionEngine;
     struct Value;
@@ -140,7 +139,7 @@ private:
     // force compile error, prevent QJSValue(bool) to be called
     QJSValue(void *) Q_DECL_EQ_DELETE;
 
-    QJSValuePrivate *d;
+    mutable quintptr d;
 };
 
 QT_END_NAMESPACE