[runtime] Fancify KeyAccumulator

src/runtime/runtime-object.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/debug/debug.h"
 #include "src/isolate-inl.h"
@@ skipping 965 matching lines @@
 RUNTIME_FUNCTION(Runtime_OwnKeys) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(JSObject, raw_object, 0);
   Handle<JSObject> object(raw_object);
 
   Handle<FixedArray> contents;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, contents, JSReceiver::GetKeys(object, JSReceiver::OWN_ONLY));
 
-  // Some fast paths through GetKeysInFixedArrayFor reuse a cached
-  // property array and since the result is mutable we have to create
-  // a fresh clone on each invocation.
   int length = contents->length();
-  Handle<FixedArray> copy = isolate->factory()->NewFixedArray(length);
   int offset = 0;
   // Use an outer loop to avoid creating too many handles in the current
   // handle scope.
   while (offset < length) {
     HandleScope scope(isolate);
     offset += 100;
     int end = Min(offset, length);
     for (int i = offset - 100; i < end; i++) {
       Object* entry = contents->get(i);
-      if (entry->IsString()) {
-        copy->set(i, entry);
-      } else {
-        DCHECK(entry->IsNumber());
-        Handle<Object> entry_handle(entry, isolate);
-        Handle<Object> entry_str =
-            isolate->factory()->NumberToString(entry_handle);
-        copy->set(i, *entry_str);
-      }
+      if (entry->IsString()) continue;
+
+      DCHECK(entry->IsNumber());
+      Handle<Object> entry_handle(entry, isolate);
+      Handle<Object> entry_str =
+          isolate->factory()->NumberToString(entry_handle);
+      contents->set(i, *entry_str);
     }
   }
-  return *isolate->factory()->NewJSArrayWithElements(copy);
+  return *isolate->factory()->NewJSArrayWithElements(contents);
 }
 
 
 RUNTIME_FUNCTION(Runtime_ToFastProperties) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
   if (object->IsJSObject() && !object->IsGlobalObject()) {
     JSObject::MigrateSlowToFast(Handle<JSObject>::cast(object), 0,
                                 "RuntimeToFastProperties");
@@ skipping 600 matching lines @@
 RUNTIME_FUNCTION(Runtime_IsAccessCheckNeeded) {
   SealHandleScope shs(isolate);
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_CHECKED(Object, object, 0);
   return isolate->heap()->ToBoolean(object->IsAccessCheckNeeded());
 }
 
 
 }  // namespace internal
 }  // namespace v8