First cut at API for ES6 ArrayBuffers

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 644 matching lines @@
   size_t allocated_length = NumberToSize(
       isolate, JSArrayBuffer::cast(*internal_object)->byte_length());
   isolate->heap()->AdjustAmountOfExternalAllocatedMemory(
       -static_cast<intptr_t>(allocated_length));
   if (data != NULL)
     free(data);
   object.Dispose(external_isolate);
 }
 
 
+bool Runtime::SetupArrayBuffer(Isolate* isolate,
+                               Handle<JSArrayBuffer> array_buffer,
+                               void* data,
+                               size_t allocated_length) {
+  array_buffer->set_backing_store(data);
+
+  Handle<Object> byte_length =
+      isolate->factory()->NewNumber(static_cast<double>(allocated_length));
+  CHECK(byte_length->IsSmi() || byte_length->IsHeapNumber());
+  array_buffer->set_byte_length(*byte_length);
+  return true;
+}
+
+
+bool Runtime::SetupArrayBufferAllocatingData(
+    Isolate* isolate,
+    Handle<JSArrayBuffer> array_buffer,
+    size_t allocated_length) {
+  void* data;
+  if (allocated_length != 0) {
+    data = malloc(allocated_length);
+    if (data == NULL) return false;
+    memset(data, 0, allocated_length);
+  } else {
+    data = NULL;
+  }
+
+  if (!SetupArrayBuffer(isolate, array_buffer, data, allocated_length))
+    return false;
+
+  v8::Isolate* external_isolate = reinterpret_cast<v8::Isolate*>(isolate);
+  v8::Persistent<v8::Value> weak_handle = v8::Persistent<v8::Value>::New(
+      external_isolate, v8::Utils::ToLocal(Handle<Object>::cast(array_buffer)));
+  weak_handle.MakeWeak(external_isolate, data, ArrayBufferWeakCallback);
+  weak_handle.MarkIndependent(external_isolate);
+  isolate->heap()->AdjustAmountOfExternalAllocatedMemory(allocated_length);
+
+  return true;
+}
+
+
 RUNTIME_FUNCTION(MaybeObject*, Runtime_ArrayBufferInitialize) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, holder, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, byteLength, 1);
   size_t allocated_length;
   if (byteLength->IsSmi()) {
     allocated_length = Smi::cast(*byteLength)->value();
   } else {
     ASSERT(byteLength->IsHeapNumber());
     double value = HeapNumber::cast(*byteLength)->value();
 
     ASSERT(value >= 0);
 
     if (value > std::numeric_limits<size_t>::max()) {
       return isolate->Throw(
           *isolate->factory()->NewRangeError("invalid_array_buffer_length",
             HandleVector<Object>(NULL, 0)));
     }
 
     allocated_length = static_cast<size_t>(value);
   }
 
-  void* data;
-  if (allocated_length != 0) {
-    data = malloc(allocated_length);
-
-    if (data == NULL) {
+  if (!Runtime::SetupArrayBufferAllocatingData(isolate,
+                                               holder, allocated_length)) {
       return isolate->Throw(*isolate->factory()->
           NewRangeError("invalid_array_buffer_length",
             HandleVector<Object>(NULL, 0)));
-    }
-
-    memset(data, 0, allocated_length);
-  } else {
-    data = NULL;
   }
-  holder->set_backing_store(data);
-
-  Object* byte_length;
-  {
-    MaybeObject* maybe_byte_length =
-        isolate->heap()->NumberFromDouble(
-            static_cast<double>(allocated_length));
-    if (!maybe_byte_length->ToObject(&byte_length)) return maybe_byte_length;
-  }
-  CHECK(byte_length->IsSmi() || byte_length->IsHeapNumber());
-  holder->set_byte_length(byte_length);
-
-  v8::Isolate* external_isolate = reinterpret_cast<v8::Isolate*>(isolate);
-  v8::Persistent<v8::Value> weak_handle = v8::Persistent<v8::Value>::New(
-      external_isolate, v8::Utils::ToLocal(Handle<Object>::cast(holder)));
-  weak_handle.MakeWeak(external_isolate, data, ArrayBufferWeakCallback);
-  weak_handle.MarkIndependent(external_isolate);
-  isolate->heap()->AdjustAmountOfExternalAllocatedMemory(allocated_length);
 
   return *holder;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_ArrayBufferGetByteLength) {
   NoHandleAllocation ha(isolate);
   ASSERT(args.length() == 1);
   CONVERT_ARG_CHECKED(JSArrayBuffer, holder, 0);
   return holder->byte_length();
@@ skipping 12620 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal