git.r.bdr.sh - rbdr/forum/blob - app/socket_coordinator.js

   1 import EventEmitter from 'eventemitter3';
   2 import { socketServer } from './config/config';
   3
   4 const internals = {
   5
   6   kReconnectInterval: 3000, // How often we attempt to reconnect
   7
   8   eventEmitter: new EventEmitter(), // internal event emitter
   9   socket: null, // stores the socket connection
  10   retry: null, // stores the retry operation
  11
  12   connect() {
  13
  14     console.debug('Connecting socket.');
  15     internals.socket = new WebSocket(socketServer);
  16
  17     internals.socket.addEventListener('message', internals.onMessage);
  18     internals.socket.addEventListener('error', internals.onError);
  19     internals.socket.addEventListener('close', internals.onClose);
  20   },
  21
  22   // Handles socket errors.
  23
  24   onError(event) {
  25
  26     console.error('Socket error. Closing connection');
  27     internals.socket.close();
  28   },
  29
  30   // Handles socket errors.
  31
  32   onClose(event) {
  33
  34     console.debug(`Connection closed: ${event.reason || 'Unknown reason'}. Retrying in ${internals.kReconnectInterval}ms`);
  35
  36     internals.retry && clearTimeout(internals.retry);
  37     internals.retry = setTimeout(() => {
  38
  39       console.debug('Reconnecting socket.');
  40       internals.retry = null;
  41       internals.connect();
  42     }, internals.kReconnectInterval);
  43   },
  44
  45   // Forwards events from the socket to our internal event emitter.
  46
  47   onMessage(event)  {
  48
  49     internals.eventEmitter.emit('message', event);
  50   }
  51 };
  52
  53 export const onMessage = function (listener) {
  54
  55   if (!internals.socket) {
  56     internals.connect();
  57   }
  58
  59   internals.eventEmitter.on('message', (message) => {
  60
  61     listener(JSON.parse(message.data));
  62   });
  63 };