QML Engine: Share data for ArrayBuffer created from QByteArray.

ExecutionEngine performs shallow copy of internal data for ArrayBuffer
created from QByteArray.

Change-Id: I514cd9708a7fbe9a989937fac62d00b464d7362d
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>
Reviewed-by: Valery Kotov <kotov.valery@gmail.com>
Reviewed-by: Pasi Keränen <pasi.keranen@digia.com>

1 files changed, 5 insertions, 8 deletions

diff --git a/src/qml/jsruntime/qv4arraybuffer_p.h b/src/qml/jsruntime/qv4arraybuffer_p.h
index 9e19a83f1e..fe3150618d 100644
--- a/src/qml/jsruntime/qv4arraybuffer_p.h
+++ b/src/qml/jsruntime/qv4arraybuffer_p.h
@@ -48,6 +48,7 @@ struct ArrayBufferCtor : FunctionObject {
 
 struct Q_QML_PRIVATE_EXPORT ArrayBuffer : Object {
     ArrayBuffer(ExecutionEngine *e, size_t length);
+    ArrayBuffer(ExecutionEngine *e, const QByteArray& array);
     ~ArrayBuffer();
     QTypedArrayData<char> *data;
 
@@ -74,15 +75,11 @@ struct Q_QML_PRIVATE_EXPORT ArrayBuffer : Object
 
     QByteArray asByteArray() const;
     uint byteLength() const { return d()->byteLength(); }
-    char *data() {
-        // ### detach if refcount > 1
-        return d()->data->data();
-    }
-    const char *constData() {
-        // ### detach if refcount > 1
-        return d()->data->data();
-    }
+    char *data() { detach(); return d()->data ? d()->data->data() : 0; }
+    const char *constData() { detach(); return d()->data ? d()->data->data() : 0; }
 
+private:
+    void detach();
 };
 
 struct ArrayBufferPrototype: Object