Ping feature (#2)

Added ping option

Author: Tom32i

demo-client.js

@@ -49,4 +49,9 @@ window.addEventListener('load', () => {
     client.addEventListener('open', () => {
         console.info('Connection open.');
     });
+
+    // Listen for connection close
+    client.addEventListener('close', () => {
+        console.info('Connection closed.');
+    });
 });

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "netcode",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "description": "NetCode for web video games",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
@@ -20,16 +20,16 @@
   ],
   "author": "Thomas Jarrand <thomas.jarrand@gmail.com> (https://thomas.jarrand.fr)",
   "license": "MIT",
+  "dependencies": {
+    "tom32i-event-emitter.js": "^2.0.1",
+    "websocket-driver": "^0.7.0"
+  },
   "devDependencies": {
     "babel-core": "^6.26.3",
     "babel-loader": "^7.1.5",
     "babel-preset-env": "^1.7.0",
-    "eslint": "^5.3.0",
-    "webpack": "^4.16.4",
-    "webpack-cli": "^3.1.0"
-  },
-  "dependencies": {
-    "tom32i-event-emitter.js": "^2.0.1",
-    "websocket-driver": "^0.7.0"
+    "eslint": "^5.8.0",
+    "webpack": "^4.25.1",
+    "webpack-cli": "^3.1.2"
   }
 }

package.json

@@ -39,7 +39,7 @@ export default class Client extends EventEmitter {
      */
     close() {
         this.socket.close();
-        this.onClose();
+        //this.onClose();
     }
 
     /**

src/client/Client.js

@@ -55,6 +55,10 @@ export default class BinaryEncoder {
      * @return {Object}
      */
     decode(buffer) {
+        if (!buffer.byteLength) {
+            throw new Error('Empty buffer');
+        }
+
         const id = this.idCodec.decode(buffer, 0);
         const handler = this.handlersById[id];
 

src/encoder/BinaryEncoder.js

@@ -0,0 +1,17 @@
+import Codec from 'netcode/src/encoder/codec/Codec';
+import BooleanCodec from 'netcode/src/encoder/codec/BooleanCodec';
+import Int8Codec from 'netcode/src/encoder/codec/Int8Codec';
+import Int16Codec from 'netcode/src/encoder/codec/Int16Codec';
+import Int32Codec from 'netcode/src/encoder/codec/Int32Codec';
+import LongIntCodec from 'netcode/src/encoder/codec/LongIntCodec';
+import StringCodec from 'netcode/src/encoder/codec/StringCodec';
+
+module.exports = {
+    Codec,
+    BooleanCodec,
+    Int8Codec,
+    Int16Codec,
+    Int32Codec,
+    LongIntCodec,
+    StringCodec,
+};

src/encoder/codec/index.js

@@ -7,23 +7,30 @@ export default class Client extends EventEmitter {
      * @param {WebSocket} socket
      * @param {String} ip
      * @param {Encoder} encoder
+     * @param {Number} pingFrequency Ping frequency in milliseconds
      */
-    constructor(socket, ip, encoder) {
+    constructor(socket, ip, encoder, pingFrequency = 0) {
         super();
 
-        this.socket = socket;
+        this.id = ++INDEX;
         this.ip = ip;
+        this.socket = socket;
         this.encoder = encoder;
-        this.id = ++INDEX;
+        this.pingInterval = null;
 
         this.onMessage = this.onMessage.bind(this);
         this.onError = this.onError.bind(this);
         this.onClose = this.onClose.bind(this);
+        this.ping = this.ping.bind(this);
 
         this.socket.on('message', this.onMessage);
         this.socket.on('error', this.onError);
         this.socket.on('close', this.onClose);
 
+        if (pingFrequency > 0) {
+            this.socket.on('open', () => this.startPing(pingFrequency));
+        }
+
         this.socket.send = this.encoder.constructor.binaryType === 'arraybuffer' ? this.socket.binary : this.socket.text;
 
         this.socket.start();
@@ -48,15 +55,46 @@ export default class Client extends EventEmitter {
         }
     }
 
+    /**
+     * Start ping at given interval
+     *
+     * @param {Number} frequency Ping frequency in milliseconds
+     */
+    startPing(frequency) {
+        if (frequency) {
+            this.pingInterval = setInterval(this.ping, frequency);
+        }
+    }
+
+    ping() {
+        if (this.socket) {
+            this.socket.ping();
+        }
+    }
+
+    /**
+     * Stop ping interval
+     */
+    stopPing() {
+        if (this.pingInterval) {
+            clearInterval(this.pingInterval);
+            this.pingInterval = null;
+        }
+    }
+
     /**
      * On message
      *
      * @param {Event} event
      */
     onMessage(event) {
-        const { name, data } = this.encoder.decode(event.data);
+        try {
+            const { name, data } = this.encoder.decode(event.data);
 
-        this.emit(name, data, this);
+            this.emit(name, data, this);
+        } catch (error) {
+            console.error('[ERROR] Could not parse message:', error, '\n\r\tEvent: ', event);
+        }
     }
 
     /**
@@ -66,12 +104,14 @@ export default class Client extends EventEmitter {
      */
     onError(event) {
         console.error(`Client ${this.id}: `, event.message);
+        this.close();
     }
 
     /**
      * On close
      */
     onClose() {
+        this.stopPing();
         this.socket = null;
         this.emit('close', this);
     }

src/server/Client.js

@@ -6,12 +6,14 @@ import Client from 'netcode/src/server/Client';
 
 export default class Server extends EventEmitter {
     /**
-     * Constructor
-     *
-     * @param {Number} port
-     * @param {String} host
+     * @param {Number} port Port
+     * @param {String} host Host
+     * @param {JsonEncoder|BinaryEncoder} encoder
+     * @param {Number} ping Ping frequency in seconds (0 for no ping)
+     * @param {Number} maxLength Paquet max length in bit
+     * @param {Array} protocols Supported protocols
      */
-    constructor(port = 8080, host = 'localhost', encoder = new JsonEncoder()) {
+    constructor(port = 8080, host = 'localhost', encoder = new JsonEncoder(), ping = 0, maxLength = Math.pow(2, 9) - 1, protocols = ['websocket']) {
         super();
 
         this.onUpgrade = this.onUpgrade.bind(this);
@@ -22,6 +24,11 @@ export default class Server extends EventEmitter {
         this.encoder = encoder;
         this.server = http.createServer();
         this.clients = new Map();
+        this.ping = ping;
+        this.options = {
+            maxLength,
+            protocols,
+        };
 
         this.server.on('error', this.onError);
         this.server.on('upgrade', this.onUpgrade);
@@ -69,24 +76,19 @@ export default class Server extends EventEmitter {
      * @param {Request} request
      * @param {Socket} socket
      * @param {Object} body
-     *
-     * @return {Boolean}
      */
     onUpgrade(request, socket, body) {
         if (!WebSocket.isWebSocket(request)) {
             return socket.end();
         }
 
         const ip = request.headers['x-real-ip'] || request.connection.remoteAddress;
-        const options = { maxLength: Math.pow(2, 9) - 1, protocols: ['websocket'] };
-        const driver = WebSocket.http(request, options);
+        const driver = WebSocket.http(request, this.options);
 
         driver.io.write(body);
         socket.pipe(driver.io).pipe(socket);
 
-        this.addClient(new Client(driver, ip, this.encoder));
-
-        return true;
+        this.addClient(new Client(driver, ip, this.encoder, this.ping * 1000));
     }
 
     /**