Support posting of external data into dart as external uint8 arrays through the Dart API.

runtime/bin/file.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/file.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/thread.h"
 #include "bin/utils.h"
@@ skipping 756 matching lines @@
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
+static void FinalizeExternalByteArray(void* peer) {
+  delete[] reinterpret_cast<uint8_t*>(peer);
+}
+
+
 static CObject* FileReadListRequest(const CObjectArray& request) {
   if (request.Length() == 3 &&
       request[1]->IsIntptr() &&
       request[2]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[1]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       int64_t length = CObjectInt32OrInt64ToInt64(request[2]);
-      CObjectUint8Array* byte_array =
-          new CObjectUint8Array(CObject::NewUint8Array(length));
-      void* buffer = reinterpret_cast<void*>(byte_array->Buffer());
-      int bytes_read = file->Read(buffer, byte_array->Length());
+      uint8_t* buffer = new uint8_t[length];
+      int bytes_read = file->Read(buffer, length);
       if (bytes_read >= 0) {
+        void* peer = reinterpret_cast<void*>(buffer);
+        CObject* external_array =
+            new CObjectExternalUint8Array(
+                CObject::NewExternalUint8Array(length,
+                                               buffer,
+                                               peer,
+                                               FinalizeExternalByteArray));
         CObjectArray* result = new CObjectArray(CObject::NewArray(3));
         result->SetAt(0, new CObjectIntptr(CObject::NewInt32(0)));
         result->SetAt(1, new CObjectIntptr(CObject::NewIntptr(bytes_read)));
-        result->SetAt(2, byte_array);
+        result->SetAt(2, external_array);
         return result;
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
@@ skipping 171 matching lines @@
   Dart_EnterScope();
   Dart_SetReturnValue(args, Dart_Null());
   Dart_Port service_port = File::GetServicePort();
   if (service_port != kIllegalPort) {
     // Return a send port for the service port.
     Dart_Handle send_port = Dart_NewSendPort(service_port);
     Dart_SetReturnValue(args, send_port);
   }
   Dart_ExitScope();
 }