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>

3 files changed, 10 insertions, 8 deletions

diff --git a/src/qml/qml/ftw/qhashedstring_p.h b/src/qml/qml/ftw/qhashedstring_p.h
index 6ff3e4a11b..03361f47f7 100644
--- a/src/qml/qml/ftw/qhashedstring_p.h
+++ b/src/qml/qml/ftw/qhashedstring_p.h
@@ -67,7 +67,7 @@ QT_BEGIN_NAMESPACE
 // #define QSTRINGHASH_LINK_DEBUG
 
 class QHashedStringRef;
-class Q_AUTOTEST_EXPORT QHashedString : public QString
+class Q_QML_PRIVATE_EXPORT QHashedString : public QString
 {
 public:
     inline QHashedString();
@@ -94,7 +94,7 @@ private:
 };
 
 class QHashedCStringRef;
-class Q_AUTOTEST_EXPORT QHashedStringRef
+class Q_QML_PRIVATE_EXPORT QHashedStringRef
 {
 public:
     inline QHashedStringRef();
diff --git a/src/qml/qml/qqmldata_p.h b/src/qml/qml/qqmldata_p.h
index 94a3b0f198..a9f2acdb06 100644
--- a/src/qml/qml/qqmldata_p.h
+++ b/src/qml/qml/qqmldata_p.h
@@ -229,7 +229,7 @@ public:
 
     static inline void flushPendingBinding(QObject *, int coreIndex);
 
-    static void ensurePropertyCache(QJSEngine *engine, QObject *object);
+    static QQmlPropertyCache *ensurePropertyCache(QJSEngine *engine, QObject *object);
 
 private:
     // For attachedProperties
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()