Accelerate access to scope object properties in lookups

Task-number: QTBUG-69898
Change-Id: I94bf1aa85c9b2302894f3224e41de81a456211f9
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

4 files changed, 94 insertions, 21 deletions

diff --git a/src/qml/jsruntime/qv4qmlcontext.cpp b/src/qml/jsruntime/qv4qmlcontext.cpp
index e728cfb457..9bdfa10030 100644
--- a/src/qml/jsruntime/qv4qmlcontext.cpp
+++ b/src/qml/jsruntime/qv4qmlcontext.cpp
@@ -261,13 +261,30 @@ ReturnedValue QQmlContextWrapper::getPropertyAndBase(const QQmlContextWrapper *r
         // Search scope object
         if (scopeObject) {
             bool hasProp = false;
+
+            QQmlPropertyData *propertyData = nullptr;
             QV4::ScopedValue result(scope, QV4::QObjectWrapper::getQmlProperty(v4, context, scopeObject,
-                                                                               name, QV4::QObjectWrapper::CheckRevision, &hasProp));
+                                                                               name, QV4::QObjectWrapper::CheckRevision, &hasProp, &propertyData));
             if (hasProp) {
                 if (hasProperty)
                     *hasProperty = true;
                 if (base)
                     *base = QV4::QObjectWrapper::wrap(v4, scopeObject);
+
+                if (lookup && propertyData) {
+                    QQmlData *ddata = QQmlData::get(scopeObject, false);
+                    if (ddata && ddata->propertyCache) {
+                        ScopedValue val(scope, base ? *base : Value::fromReturnedValue(QV4::QObjectWrapper::wrap(v4, scopeObject)));
+                        const QObjectWrapper *That = static_cast<const QObjectWrapper *>(val->objectValue());
+                        lookup->qobjectLookup.ic = That->internalClass();
+                        lookup->qobjectLookup.staticQObject = nullptr;
+                        lookup->qobjectLookup.propertyCache = ddata->propertyCache;
+                        lookup->qobjectLookup.propertyCache->addref();
+                        lookup->qobjectLookup.propertyData = propertyData;
+                        lookup->qmlContextPropertyGetter = QQmlContextWrapper::lookupScopeObjectProperty;
+                    }
+                }
+
                 return result->asReturnedValue();
             }
         }
@@ -466,6 +483,32 @@ ReturnedValue QQmlContextWrapper::lookupIdObject(Lookup *l, ExecutionEngine *eng
     return QV4::QObjectWrapper::wrap(engine, context->idValues[objectId]);
 }
 
+ReturnedValue QQmlContextWrapper::lookupScopeObjectProperty(Lookup *l, ExecutionEngine *engine, Value *base)
+{
+    Q_UNUSED(base)
+    Scope scope(engine);
+    Scoped<QmlContext> qmlContext(scope, engine->qmlContext());
+    if (!qmlContext)
+        return QV4::Encode::undefined();
+
+    QObject *scopeObject = qmlContext->qmlScope();
+    if (!scopeObject)
+        return QV4::Encode::undefined();
+
+    if (QQmlData::wasDeleted(scopeObject))
+        return QV4::Encode::undefined();
+
+    const auto revertLookup = [l, engine, base]() {
+        l->qobjectLookup.propertyCache->release();
+        l->qobjectLookup.propertyCache = nullptr;
+        l->qmlContextPropertyGetter = QQmlContextWrapper::resolveQmlContextPropertyLookupGetter;
+        return QQmlContextWrapper::resolveQmlContextPropertyLookupGetter(l, engine, base);
+    };
+
+    ScopedValue obj(scope, QV4::QObjectWrapper::wrap(engine, scopeObject));
+    return QObjectWrapper::lookupGetterImpl(l, engine, obj, /*useOriginalProperty*/ true, revertLookup);
+}
+
 ReturnedValue QQmlContextWrapper::lookupInGlobalObject(Lookup *l, ExecutionEngine *engine, Value *base)
 {
     Q_UNUSED(base);
diff --git a/src/qml/jsruntime/qv4qmlcontext_p.h b/src/qml/jsruntime/qv4qmlcontext_p.h
index cfcc53c7c9..83bf2a1d3e 100644
--- a/src/qml/jsruntime/qv4qmlcontext_p.h
+++ b/src/qml/jsruntime/qv4qmlcontext_p.h
@@ -108,6 +108,7 @@ struct Q_QML_EXPORT QQmlContextWrapper : Object
     static ReturnedValue lookupScript(Lookup *l, ExecutionEngine *engine, Value *base);
     static ReturnedValue lookupSingleton(Lookup *l, ExecutionEngine *engine, Value *base);
     static ReturnedValue lookupIdObject(Lookup *l, ExecutionEngine *engine, Value *base);
+    static ReturnedValue lookupScopeObjectProperty(Lookup *l, ExecutionEngine *engine, Value *base);
     static ReturnedValue lookupInGlobalObject(Lookup *l, ExecutionEngine *engine, Value *base);
 };
 
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index 351076ac28..377c30617a 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -357,7 +357,7 @@ ReturnedValue QObjectWrapper::getQmlProperty(QQmlContextData *qmlContext, String
     return getProperty(v4, d()->object(), result);
 }
 
-ReturnedValue QObjectWrapper::getQmlProperty(QV4::ExecutionEngine *engine, QQmlContextData *qmlContext, QObject *object, String *name, QObjectWrapper::RevisionMode revisionMode, bool *hasProperty)
+ReturnedValue QObjectWrapper::getQmlProperty(QV4::ExecutionEngine *engine, QQmlContextData *qmlContext, QObject *object, String *name, QObjectWrapper::RevisionMode revisionMode, bool *hasProperty, QQmlPropertyData **property)
 {
     if (QQmlData::wasDeleted(object)) {
         if (hasProperty)
@@ -384,6 +384,9 @@ ReturnedValue QObjectWrapper::getQmlProperty(QV4::ExecutionEngine *engine, QQmlC
         if (hasProperty)
             *hasProperty = true;
 
+        if (property)
+            *property = result;
+
         return getProperty(engine, object, result);
     } else {
         // Check if this object is already wrapped.
@@ -884,24 +887,7 @@ ReturnedValue QObjectWrapper::lookupGetter(Lookup *lookup, ExecutionEngine *engi
         return Lookup::getterGeneric(lookup, engine, object);
     };
 
-    // we can safely cast to a QV4::Object here. If object is something else,
-    // the internal class won't match
-    Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
-    if (!o || o->internalClass != lookup->qobjectLookup.ic)
-        return revertLookup();
-
-    const Heap::QObjectWrapper *This = lookup->qobjectLookup.staticQObject ? lookup->qobjectLookup.staticQObject :
-                                                                             static_cast<const Heap::QObjectWrapper *>(o);
-    QObject *qobj = This->object();
-    if (QQmlData::wasDeleted(qobj))
-        return QV4::Encode::undefined();
-
-    QQmlData *ddata = QQmlData::get(qobj, /*create*/false);
-    if (!ddata || ddata->propertyCache != lookup->qobjectLookup.propertyCache)
-        return revertLookup();
-
-    QQmlPropertyData *property = lookup->qobjectLookup.propertyData;
-    return getProperty(engine, qobj, property);
+    return lookupGetterImpl(lookup, engine, object, /*useOriginalProperty*/ false, revertLookup);
 }
 
 bool QObjectWrapper::virtualResolveLookupSetter(Object *object, ExecutionEngine *engine, Lookup *lookup,
diff --git a/src/qml/jsruntime/qv4qobjectwrapper_p.h b/src/qml/jsruntime/qv4qobjectwrapper_p.h
index 471f352c2a..2558ede401 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper_p.h
+++ b/src/qml/jsruntime/qv4qobjectwrapper_p.h
@@ -62,6 +62,7 @@
 
 #include <private/qv4value_p.h>
 #include <private/qv4functionobject_p.h>
+#include <private/qv4lookup_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -167,7 +168,7 @@ struct Q_QML_EXPORT QObjectWrapper : public Object
     QObject *object() const { return d()->object(); }
 
     ReturnedValue getQmlProperty(QQmlContextData *qmlContext, String *name, RevisionMode revisionMode, bool *hasProperty = nullptr, bool includeImports = false) const;
-    static ReturnedValue getQmlProperty(ExecutionEngine *engine, QQmlContextData *qmlContext, QObject *object, String *name, RevisionMode revisionMode, bool *hasProperty = nullptr);
+    static ReturnedValue getQmlProperty(ExecutionEngine *engine, QQmlContextData *qmlContext, QObject *object, String *name, RevisionMode revisionMode, bool *hasProperty = nullptr, QQmlPropertyData **property = nullptr);
 
     static bool setQmlProperty(ExecutionEngine *engine, QQmlContextData *qmlContext, QObject *object, String *name, RevisionMode revisionMode, const Value &value);
 
@@ -185,6 +186,7 @@ struct Q_QML_EXPORT QObjectWrapper : public Object
 
     static ReturnedValue virtualResolveLookupGetter(const Object *object, ExecutionEngine *engine, Lookup *lookup);
     static ReturnedValue lookupGetter(Lookup *l, ExecutionEngine *engine, const Value &object);
+    template <typename ReversalFunctor> static ReturnedValue lookupGetterImpl(Lookup *l, ExecutionEngine *engine, const Value &object, bool useOriginalProperty, ReversalFunctor revert);
     static bool virtualResolveLookupSetter(Object *object, ExecutionEngine *engine, Lookup *lookup, const Value &value);
 
 protected:
@@ -222,6 +224,47 @@ inline ReturnedValue QObjectWrapper::wrap(ExecutionEngine *engine, QObject *obje
     return wrap_slowPath(engine, object);
 }
 
+template <typename ReversalFunctor>
+inline ReturnedValue QObjectWrapper::lookupGetterImpl(Lookup *lookup, ExecutionEngine *engine, const Value &object, bool useOriginalProperty, ReversalFunctor revertLookup)
+{
+    // we can safely cast to a QV4::Object here. If object is something else,
+    // the internal class won't match
+    Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
+    if (!o || o->internalClass != lookup->qobjectLookup.ic)
+        return revertLookup();
+
+    const Heap::QObjectWrapper *This = lookup->qobjectLookup.staticQObject ? lookup->qobjectLookup.staticQObject :
+                                                                             static_cast<const Heap::QObjectWrapper *>(o);
+    QObject *qobj = This->object();
+    if (QQmlData::wasDeleted(qobj))
+        return QV4::Encode::undefined();
+
+    QQmlData *ddata = QQmlData::get(qobj, /*create*/false);
+    if (!ddata)
+        return revertLookup();
+
+    QQmlPropertyData *property = lookup->qobjectLookup.propertyData;
+    if (ddata->propertyCache != lookup->qobjectLookup.propertyCache) {
+        if (property->isOverridden() && (!useOriginalProperty || property->isFunction() || property->isSignalHandler()))
+            return revertLookup();
+
+        QQmlPropertyCache *fromMo = ddata->propertyCache;
+        QQmlPropertyCache *toMo = lookup->qobjectLookup.propertyCache;
+        bool canConvert = false;
+        while (fromMo) {
+            if (fromMo == toMo) {
+                canConvert = true;
+                break;
+            }
+            fromMo = fromMo->parent();
+        }
+        if (!canConvert)
+            return revertLookup();
+    }
+
+    return getProperty(engine, qobj, property);
+}
+
 struct QQmlValueTypeWrapper;
 
 struct Q_QML_EXPORT QObjectMethod : public QV4::FunctionObject