Serialize binary barback assets using typed arrays.

pkg/barback/lib/src/internal_asset.dart

 // Copyright (c) 2013, 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.
 
 library barback.internal_asset;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
+import 'dart:typed_data';
 
 import 'asset.dart';
 import 'asset_id.dart';
 import 'file_pool.dart';
 import 'serialize.dart';
 import 'stream_replayer.dart';
 import 'utils.dart';
 
 /// Serialize an asset to a form that's safe to send across isolates.
 Map serializeAsset(Asset asset) {
   var id = serializeId(asset.id);
   if (asset is BinaryAsset) {
-    // If [_contents] is a custom subclass of List, it won't be serializable, so
-    // we have to convert it to a built-in [List] first.
-    // TODO(nweiz): Send a typed array if that works after issue 14703 is fixed.
-    var contents = asset._contents.runtimeType == List ?
-        asset._contents : asset._contents.toList();
-
     return {
       'type': 'binary',
       'id': id,
-      'contents': contents
+      'contents': asset._contents
     };
   } else if (asset is FileAsset) {
     return {
       'type': 'file',
       'id': id,
       'path': asset._path
     };
   } else if (asset is StringAsset) {
     return {
       'type': 'string',
@@ skipping 23 matching lines @@
       return new StreamAsset(id, deserializeStream(asset['stream']));
     default:
       throw new FormatException('Unknown asset type "${asset['type']}".');
   }
 }
 
 /// An asset whose data is stored in a list of bytes.
 class BinaryAsset implements Asset {
   final AssetId id;
 
-  final List<int> _contents;
+  final Uint8List _contents;
 
-  BinaryAsset(this.id, this._contents);
+  BinaryAsset(this.id, List<int> contents)
+      : _contents = toUint8List(contents);
 
   Future<String> readAsString({Encoding encoding}) {
     if (encoding == null) encoding = UTF8;
 
     return new Future.value(encoding.decode(_contents));
   }
 
   Stream<List<int>> read() => new Future<List<int>>.value(_contents).asStream();
 
   String toString() {
@@ skipping 95 matching lines @@
   Future<String> readAsString({Encoding encoding}) {
     if (encoding == null) encoding = UTF8;
     return _replayer.getReplay().toList()
         .then((chunks) => encoding.decode(flatten(chunks)));
   }
 
   Stream<List<int>> read() => _replayer.getReplay();
 
   String toString() => "Stream";
 }