Use ByteArray's native for Socket and File.

runtime/bin/file_impl.dart

 // 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.
 
 class _FileInputStream extends _BaseDataInputStream implements InputStream {
   _FileInputStream(File file) {
     _file = file.openSync();
     _length = _file.lengthSync();
     _streamMarkedClosed = true;
     _checkScheduleCallbacks();
   }
 
   int available() {
     return _closed ? 0 : _length - _file.positionSync();
   }
 
   void pipe(OutputStream output, [bool close = true]) {
     _pipe(this, output, close: close);
   }
 
   List<int> _read(int bytesToRead) {
-    List<int> result = new List<int>(bytesToRead);
+    ByteArray result = new ByteArray(bytesToRead);
     int bytesRead = _file.readListSync(result, 0, bytesToRead);
     if (bytesRead < bytesToRead) {
-      List<int> buffer = new List<int>(bytesRead);
-      buffer.copyFrom(result, 0, 0, bytesRead);
+      ByteArray buffer = new ByteArray(bytesRead);
+      buffer.setRange(0, bytesRead, result);
       result = buffer;
     }
     _checkScheduleCallbacks();
     return result;
   }
 
   int _readInto(List<int> buffer, int offset, int len) {
     int result = _file.readListSync(buffer, offset, len);
     _checkScheduleCallbacks();
     return result;
@@ skipping 131 matching lines @@
       _replyPort.send(0, port.toSendPort());
       return;
     }
     int index =
         _FileUtils.checkReadWriteListArguments(_length, _offset, _bytes);
     if (index != 0) {
       _replyPort.send("index out of range in readList: $index",
                       port.toSendPort());
       return;
     }
-    var buffer = new List(_bytes);
+    ByteArray buffer = new ByteArray(_bytes);
     var result =
         new _ReadListResult(_FileUtils.readList(_id, buffer, 0, _bytes),
                             buffer);
     _replyPort.send(result, port.toSendPort());
   }
 
   int _id;
   int _length;
   int _offset;
   int _bytes;
@@ skipping 225 matching lines @@
   static int open(String name, int mode) native "File_Open";
   static bool create(String name) native "File_Create";
   static bool delete(String name) native "File_Delete";
   static String fullPath(String name) native "File_FullPath";
   static int close(int id) native "File_Close";
   static int readByte(int id) native "File_ReadByte";
   static int readList(int id, List<int> buffer, int offset, int bytes)
       native "File_ReadList";
   static int writeByte(int id, int value) native "File_WriteByte";
   static int writeList(int id, List<int> buffer, int offset, int bytes) {
-    // When using the Dart C API access to ObjectArray by index is
+    // When using the Dart C API to access raw data, using a ByteArray is
     // currently much faster. This function will make a copy of the
-    // supplied List to an ObjectArray if it isn't already.
-    ObjectArray outBuffer;
+    // supplied List to a ByteArray if it isn't already.
+    List outBuffer;
     int outOffset = offset;
-    if (buffer is ObjectArray) {
+    if (buffer is ByteArray || buffer is ObjectArray) {
       outBuffer = buffer;
     } else {
-      outBuffer = new ObjectArray(bytes);
+      outBuffer = new ByteArray(bytes);
       outOffset = 0;
       int j = offset;
       for (int i = 0; i < bytes; i++) {
-        outBuffer[i] = buffer[j];
+        int value = buffer[j];
+        if (value is! int) {
+          throw new FileIOException(
+              "List element is not an integer at index $j");
+        }
+        outBuffer[i] = value;
         j++;
       }
     }
     return writeListNative(id, outBuffer, outOffset, bytes);
   }
   static int writeListNative(int id, List<int> buffer, int offset, int bytes)
       native "File_WriteList";
   static int writeString(int id, String string) native "File_WriteString";
   static int position(int id) native "File_Position";
   static bool setPosition(int id, int position) native "File_SetPosition";
@@ skipping 635 matching lines @@
   var _readByteHandler;
   var _readListHandler;
   var _noPendingWriteHandler;
   var _positionHandler;
   var _setPositionHandler;
   var _truncateHandler;
   var _lengthHandler;
   var _flushHandler;
   var _errorHandler;
 }