--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/runtime/PropertyNameArray.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,53 @@
+/*
+ *  Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public License
+ *  along with this library; see the file COPYING.LIB.  If not, write to
+ *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "config.h"
+#include "PropertyNameArray.h"
+
+#include "Structure.h"
+#include "StructureChain.h"
+
+namespace JSC {
+
+static const size_t setThreshold = 20;
+
+void PropertyNameArray::add(UString::Rep* identifier)
+{
+    ASSERT(identifier == UString::null().rep() || identifier == UString::Rep::empty() || identifier->isIdentifier());
+
+    size_t size = m_data->propertyNameVector().size();
+    if (size < setThreshold) {
+        for (size_t i = 0; i < size; ++i) {
+            if (identifier == m_data->propertyNameVector()[i].ustring().rep())
+                return;
+        }
+    } else {
+        if (m_set.isEmpty()) {
+            for (size_t i = 0; i < size; ++i)
+                m_set.add(m_data->propertyNameVector()[i].ustring().rep());
+        }
+        if (!m_set.add(identifier).second)
+            return;
+    }
+
+    addKnownUnique(identifier);
+}
+
+} // namespace JSC