QtQuick: clean up shader effect property connections

- Don't use a signal mapper, but handle the mapping using a custom slot
  object and a lambda to do the dispatching ourselves.
- Don't do meta-calls by property name, but by index.
- Cache the meta-object.
- Resolve the property indices by using the QML property cache.

For a shader with 6 property connections, the time spent goes from 320k
instructions to 80k instructions (valgrind on x86_64).

Task-number: QTBUG-53901
Change-Id: I2809198cf62f9716b3683798222203fc3e97fbb3
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>

1 files changed, 7 insertions, 5 deletions

diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index 6cd32852e1..f7191feec5 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -1805,14 +1805,16 @@ void QQmlData::setPendingBindingBit(QObject *obj, int coreIndex)
     QQmlData_setBit(this, obj, coreIndex * 2 + 1);
 }
 
-void QQmlData::ensurePropertyCache(QJSEngine *engine, QObject *object)
+QQmlPropertyCache *QQmlData::ensurePropertyCache(QJSEngine *engine, QObject *object)
 {
     Q_ASSERT(engine);
     QQmlData *ddata = QQmlData::get(object, /*create*/true);
-    if (ddata->propertyCache)
-        return;
-    ddata->propertyCache = QJSEnginePrivate::get(engine)->cache(object);
-    if (ddata->propertyCache) ddata->propertyCache->addref();
+    if (!ddata->propertyCache) {
+        ddata->propertyCache = QJSEnginePrivate::get(engine)->cache(object);
+        if (ddata->propertyCache)
+            ddata->propertyCache->addref();
+    }
+    return ddata->propertyCache;
 }
 
 void QQmlEnginePrivate::sendQuit()