Expose Cloning through API.

Review URL: http://codereview.chromium.org/42339

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -1076,6 +1076,12 @@ class V8EXPORT Object : public Value {
    */
   void TurnOnAccessCheck();
 
+  /**
+   * Clone this object with a fast but shallow copy.  Values will point
+   * to the same values as the original object.
+   */
+  Local<Object> Clone();
+
   static Local<Object> New();
   static Object* Cast(Value* obj);
  private:

src/api.cc

@@ -1919,6 +1919,17 @@ void v8::Object::TurnOnAccessCheck() {
 }
 
 
+Local<v8::Object> v8::Object::Clone() {
+  ON_BAILOUT("v8::Object::Clone()", return Local<Object>());
+  i::Handle<i::JSObject> self = Utils::OpenHandle(this);
+  EXCEPTION_PREAMBLE();
+  i::Handle<i::JSObject> result = i::Copy(self);
+  has_pending_exception = result.is_null();
+  EXCEPTION_BAILOUT_CHECK(Local<Object>());
+  return Utils::ToLocal(result);
+}
+
+
 Local<v8::Object> Function::NewInstance() const {
   return NewInstance(0, NULL);
 }

test/cctest/test-api.cc

@@ -5803,3 +5803,38 @@ TEST(RegExpInterruption) {
 
   local_env->Exit();
 }
+
+
+// Verify that we can clone an object
+TEST(ObjectClone) {
+  v8::HandleScope scope;
+  LocalContext env;
+
+  char* sample =
+    "var rv = {};"      \
+    "rv.alpha = 'hello';" \
+    "rv.beta = 123;"     \
+    "rv;";
+
+  // Create an object, verify basics.
+  Local<Value> val = CompileRun(sample);
+  CHECK(val->IsObject());
+  Local<v8::Object> obj = Local<v8::Object>::Cast(val);
+  obj->Set(v8_str("gamma"), v8_str("cloneme"));
+
+  CHECK_EQ(v8_str("hello"), obj->Get(v8_str("alpha")));
+  CHECK_EQ(v8::Integer::New(123), obj->Get(v8_str("beta")));
+  CHECK_EQ(v8_str("cloneme"), obj->Get(v8_str("gamma")));
+
+  // Clone it.
+  Local<v8::Object> clone = obj->Clone();
+  CHECK_EQ(v8_str("hello"), clone->Get(v8_str("alpha")));
+  CHECK_EQ(v8::Integer::New(123), clone->Get(v8_str("beta")));
+  CHECK_EQ(v8_str("cloneme"), clone->Get(v8_str("gamma")));
+
+  // Set a property on the clone, verify each object.
+  clone->Set(v8_str("beta"), v8::Integer::New(456));
+  CHECK_EQ(v8::Integer::New(123), obj->Get(v8_str("beta")));
+  CHECK_EQ(v8::Integer::New(456), clone->Get(v8_str("beta")));
+}
+