@rtsdk/lance-topia/src/network/NetworkMonitor.js

A Node.js based real-time multiplayer game server

import EventEmitter from "event-emitter";
// import http from 'http';

/**
 * Measures network performance between the client and the server
 * Represents both the client and server portions of NetworkMonitor
 */
export default class NetworkMonitor {
  constructor(server) {
    // server-side keep game name
    if (server) {
      this.server = server;
      this.gameName = Object.getPrototypeOf(server.gameEngine).constructor.name;
    }

    // mixin for EventEmitter
    let eventEmitter = new EventEmitter();
    this.on = eventEmitter.on;
    this.once = eventEmitter.once;
    this.removeListener = eventEmitter.removeListener;
    this.emit = eventEmitter.emit;
  }

  // client
  registerClient(clientEngine) {
    this.queryIdCounter = 0;
    this.RTTQueries = {};

    this.movingRTTAverage = 0;
    this.movingRTTAverageFrame = [];
    this.movingFPSAverageSize = clientEngine.options.healthCheckRTTSample;
    this.clientEngine = clientEngine;
    clientEngine.socket.on("RTTResponse", this.onReceivedRTTQuery.bind(this));
    setInterval(this.sendRTTQuery.bind(this), clientEngine.options.healthCheckInterval);
  }

  sendRTTQuery() {
    // todo implement cleanup of older timestamp
    this.RTTQueries[this.queryIdCounter] = new Date().getTime();
    this.clientEngine.socket.emit("RTTQuery", this.queryIdCounter);
    this.queryIdCounter++;
  }

  onReceivedRTTQuery(queryId) {
    let RTT = new Date().getTime() - this.RTTQueries[queryId];

    this.movingRTTAverageFrame.push(RTT);
    if (this.movingRTTAverageFrame.length > this.movingFPSAverageSize) {
      this.movingRTTAverageFrame.shift();
    }
    this.movingRTTAverage = this.movingRTTAverageFrame.reduce((a, b) => a + b) / this.movingRTTAverageFrame.length;
    this.emit("RTTUpdate", {
      RTT: RTT,
      RTTAverage: this.movingRTTAverage,
    });
  }

  // server
  registerPlayerOnServer(socket) {
    socket.on("RTTQuery", this.respondToRTTQuery.bind(this, socket));
    // if (this.server && this.server.options.countConnections) {
    //     http.get(`http://ping.games-eu.lance.gg:2000/${this.gameName}`).on('error', () => {});
    // }
  }

  respondToRTTQuery(socket, queryId) {
    socket.emit("RTTResponse", queryId);
  }
}