runtime/observatory_2/lib/service_html.dart

// Copyright (c) 2014, 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 service_html;

import 'dart:async';
import 'dart:convert';
import 'dart:html';
import 'dart:typed_data';

import 'package:observatory_2/service_common.dart';

// Export the service library.
export 'package:observatory_2/service_common.dart';

class _HtmlWebSocket implements CommonWebSocket {
  WebSocket _webSocket;

  Future<void> connect(WebSocketVMTarget target, void onOpen(),
      void onMessage(dynamic data), void onError(), void onClose()) async {
    // The VM service will attempt to redirect our websocket connection request
    // to DDS, but the dart:html WebSocket doesn't follow redirects. Instead of
    // relying on a redirect, we'll request the websocket URI from the service.

    // TODO(bkonyi): re-enable when DDS is enabled. Currently causing Observatory
    // failures when running with Flutter (see
    // https://github.com/flutter/flutter/issues/64333)
    /*Uri getWebSocketUriRequest = Uri.parse(target.networkAddress);
    getWebSocketUriRequest =
        getWebSocketUriRequest.replace(scheme: 'http', pathSegments: [
      ...getWebSocketUriRequest.pathSegments.where((e) => e != 'ws'),
      'getWebSocketTarget',
    ]);
    final response = json.decode(await HttpRequest.getString(
      getWebSocketUriRequest.toString(),
    ));
    if (!response.containsKey('result') ||
        !response['result'].containsKey('uri')) {
      onError();
      return;
    }
    target.networkAddress = response['result']['uri'];
    */
    _webSocket = new WebSocket(target.networkAddress);
    _webSocket.onClose.listen((CloseEvent) => onClose());
    _webSocket.onError.listen((Event) => onError());
    _webSocket.onOpen.listen((Event) => onOpen());
    _webSocket.onMessage.listen((MessageEvent event) => onMessage(event.data));
  }

  bool get isOpen => _webSocket.readyState == WebSocket.OPEN;

  void send(dynamic data) {
    _webSocket.send(data);
  }

  void close() {
    _webSocket.close();
  }

  Future<ByteData> nonStringToByteData(dynamic data) {
    assert(data is Blob);
    FileReader fileReader = new FileReader();
    fileReader.readAsArrayBuffer(data);
    return fileReader.onLoadEnd.first.then((e) {
      Uint8List result = fileReader.result as Uint8List;
      return new ByteData.view(
          result.buffer, result.offsetInBytes, result.length);
    });
  }
}

/// The [WebSocketVM] communicates with a Dart VM over WebSocket. The Dart VM
/// can be embedded in Chromium or standalone. In the case of Chromium, we
/// make the service requests via the Chrome Remote Debugging Protocol.
class WebSocketVM extends CommonWebSocketVM {
  WebSocketVM(WebSocketVMTarget target) : super(target, new _HtmlWebSocket());
}