kami-parse-server/src/LiveQuery/ParseWebSocketServer.js

import { loadAdapter } from '../Adapters/AdapterLoader';
import { WSAdapter } from '../Adapters/WebSocketServer/WSAdapter';
import logger from '../logger';
import events from 'events';

export class ParseWebSocketServer {
  server: Object;

  constructor(
    server: any,
    onConnect: Function,
    config
  ) {
    config.server = server;
    const wss = loadAdapter(
      config.wssAdapter,
      WSAdapter,
      config,
    );
    wss.onListen = () => {
      logger.info('Parse LiveQuery Server starts running');
    };
    wss.onConnection = (ws) => {
      onConnect(new ParseWebSocket(ws));
      // Send ping to client periodically
      const pingIntervalId = setInterval(() => {
        if (ws.readyState == ws.OPEN) {
          ws.ping();
        } else {
          clearInterval(pingIntervalId);
        }
      }, config.websocketTimeout || 10 * 1000);
    };
    wss.start();
    this.server = wss;
  }

  close() {
    if (this.server && this.server.close) {
      this.server.close();
    }
  }
}

export class ParseWebSocket extends events.EventEmitter {
  ws: any;

  constructor(ws: any) {
    super();
    ws.onmessage = (request) => this.emit('message', request);
    ws.onclose = () => this.emit('disconnect');
    this.ws = ws;
  }

  send(message: any): void {
    this.ws.send(message);
  }
}