Add an external array type to support typed arrays.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index a00c5049b767f339f3ba80d2c723d1f042c4a7fb..e809b0cb98ce03f84f6869c0f69c7d0a62a231fd 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -397,6 +397,9 @@ void Object::Init(Isolate* isolate) {
   cls = Class::New<Bool>();
   object_store->set_bool_class(cls);
 
+  cls = Class::New<ByteBuffer>();
+  object_store->set_byte_buffer_class(cls);
+
   cls = Class::New<UnhandledException>();
   object_store->set_unhandled_exception_class(cls);
 
@@ -527,6 +530,12 @@ void Object::Init(Isolate* isolate) {
   cls.set_script(script);
   core_lib.AddClass(cls);
 
+  name = String::NewSymbol("ByteBuffer");
+  cls = object_store->byte_buffer_class();
+  cls.set_name(name);
+  cls.set_script(script);
+  core_lib.AddClass(cls);
+
   name = String::NewSymbol("Function");
   cls = Class::NewInterface(name, script);
   core_lib.AddClass(cls);
@@ -625,6 +634,9 @@ void Object::InitFromSnapshot(Isolate* isolate) {
   cls = Class::New<ImmutableArray>();
   object_store->set_immutable_array_class(cls);
 
+  cls = Class::New<ByteBuffer>();
+  object_store->set_byte_buffer_class(cls);
+
   cls = Class::New<Instance>();
   object_store->set_object_class(cls);
 
@@ -1109,6 +1121,9 @@ RawClass* Class::GetClass(ObjectKind kind) {
     case kImmutableArray:
       ASSERT(object_store->immutable_array_class() != Class::null());
       return object_store->immutable_array_class();
+    case kByteBuffer:
+      ASSERT(object_store->byte_buffer_class() != Class::null());
+      return object_store->byte_buffer_class();
     case kStacktrace:
       ASSERT(object_store->stacktrace_class() != Class::null());
       return object_store->stacktrace_class();
@@ -6662,6 +6677,53 @@ const char* ImmutableArray::ToCString() const {
 }
 
 
+RawByteBuffer* ByteBuffer::New(uint8_t* data,
+                               intptr_t len,
+                               Heap::Space space) {
+  Isolate* isolate = Isolate::Current();
+  const Class& byte_buffer_class =
+      Class::Handle(isolate->object_store()->byte_buffer_class());
+  ByteBuffer& result = ByteBuffer::Handle();
+  {
+    RawObject* raw = Object::Allocate(byte_buffer_class,
+                                      ByteBuffer::InstanceSize(),
+                                      space);
+    NoGCScope no_gc;
+    result ^= raw;
+    result.SetLength(len);
+    result.SetData(data);
+  }
+  return result.raw();
+}
+
+
+bool ByteBuffer::Equals(const Instance& other) const {
+  if (this->raw() == other.raw()) {
+    // Both handles point to the same raw instance.
+    return true;
+  }
+
+  if (!other.IsByteBuffer() || other.IsNull()) {
+    return false;
+  }
+
+  ByteBuffer& other_array = ByteBuffer::Handle();
+  other_array ^= other.raw();
+
+  intptr_t len = this->Length();
+  if (len != other_array.Length()) {
+    return false;
+  }
+
+  return !memcmp(this->Addr<uint8_t>(0), other_array.Addr<uint8_t>(0), len);

[Ivan Posva, 2011/11/16 22:50:01]

Please do not use ints as boolean:
return memcmp(....) == 0;

[cshapiro, 2011/11/17 03:17:02]

Certainly.  Done.

+}
+
+
+const char* ByteBuffer::ToCString() const {
+  return "ByteBuffer";
+}
+
+
 RawClosure* Closure::New(const Function& function,
                          const Context& context,
                          Heap::Space space) {