move polymer.dart into dart svn

pkg/polymer/lib/src/file_system/console.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.
+
+library console;
+
+import 'dart:async';
+import 'dart:io';
+import 'dart:utf';
+import 'package:polymer/src/file_system.dart';
+
+/** File system implementation for console VM (i.e. no browser). */
+class ConsoleFileSystem implements FileSystem {
+
+  /** Pending futures for file write requests. */
+  final _pending = <String, Future>{};
+
+  Future flush() => Future.wait(_pending.values.toList());
+
+  void writeString(String path, String text) {
+    if(!_pending.containsKey(path)) {
+      _pending[path] = new File(path).open(mode: FileMode.WRITE)
+          .then((file) => file.writeString(text))
+          .then((file) => file.close())
+          .whenComplete(() { _pending.remove(path); });
+    }
+  }
+
+  // TODO(jmesserly): even better would be to pass the RandomAccessFile directly
+  // to html5lib. This will require a further restructuring of FileSystem.
+  // Probably it just needs "readHtml" and "readText" methods.
+  Future<List<int>> readTextOrBytes(String path) {
+    return new File(path).open().then(
+        (file) => file.length().then((length) {
+      // TODO(jmesserly): is this guaranteed to read all of the bytes?
+      var buffer = new List<int>(length);
+      return file.readInto(buffer, 0, length)
+          .then((_) => file.close())
+          .then((_) => buffer);
+    }));
+  }
+
+  // TODO(jmesserly): do we support any encoding other than UTF-8 for Dart?
+  Future<String> readText(String path) {
+    return readTextOrBytes(path).then(decodeUtf8);
+  }
+}