Fix performance regression when doing property lookups for non-existant properties

Commit 84627464eb11ca1149d46946b12e3c82eb54a8bf introduced a performance
regression of falling back to reading the QMetaObject, when the lookup for a
property in QML failed, after we've tried in the property cache. This is very
very expensive to do and was only due to QQmlPropertyMap not correctly
invalidating the property cache.

Instead remove the property cache from the property map's QObject and on the
lookup side rely on the property cache being correct in the result (positive or
negative).

Change-Id: I8a013483203f2007d48b71feafa10b3ea02c53fd
Reviewed-by: Lars Knoll <[email protected]>

3 files changed, 14 insertions, 6 deletions

diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index 03d839316b..c4566fe2a3 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -263,7 +263,7 @@ QQmlPropertyData *QObjectWrapper::findProperty(ExecutionEngine *engine, QQmlCont
     QQmlPropertyData *result = 0;
     if (ddata && ddata->propertyCache)
         result = ddata->propertyCache->property(name, m_object, qmlContext);
-    if (!result)
+    else
         result = QQmlPropertyCache::property(engine->v8Engine->engine(), m_object, name, qmlContext, *local);
     return result;
 }
diff --git a/src/qml/qml/qqmlopenmetaobject.cpp b/src/qml/qml/qqmlopenmetaobject.cpp
index 278287e697..5745f35498 100644
--- a/src/qml/qml/qqmlopenmetaobject.cpp
+++ b/src/qml/qml/qqmlopenmetaobject.cpp
@@ -357,9 +357,18 @@ void QQmlOpenMetaObject::setCached(bool c)
 
 int QQmlOpenMetaObject::createProperty(const char *name, const char *)
 {
-    if (d->autoCreate)
-        return d->type->createProperty(name);
-    else
+    if (d->autoCreate) {
+        int result = d->type->createProperty(name);
+
+        if (QQmlData *ddata = QQmlData::get(d->object, /*create*/false)) {
+            if (ddata->propertyCache) {
+                ddata->propertyCache->release();
+                ddata->propertyCache = 0;
+            }
+        }
+
+        return result;
+    } else
         return -1;
 }
 
diff --git a/src/qml/qml/qqmlpropertycache.cpp b/src/qml/qml/qqmlpropertycache.cpp
index e498ca5dee..2cb944d824 100644
--- a/src/qml/qml/qqmlpropertycache.cpp
+++ b/src/qml/qml/qqmlpropertycache.cpp
@@ -1419,8 +1419,7 @@ qQmlPropertyCacheProperty(QQmlEngine *engine, QObject *obj, T name,
 
     if (cache) {
         rv = cache->property(name, obj, context);
-    }
-    if (!rv) {
+    } else {
         local = qQmlPropertyCacheCreate(obj->metaObject(), qQmlPropertyCacheToString(name));
         if (local.isValid())
             rv = &local;