replace socket.io usage with WebSockets

lib/app.js

@@ -2,6 +2,7 @@ const Database = require('./database')
 const MojangUpdater = require('./mojang')
 const PingController = require('./ping')
 const Server = require('./server')
+const MessageOf = require('./message')
 
 const config = require('../config')
 const minecraftVersions = require('../minecraft_versions')
@@ -36,43 +37,46 @@ class App {
 
   handleClientConnection = (client) => {
     if (config.logToDatabase) {
-      client.on('requestHistoryGraph', () => {
-        // Send historical graphData built from all serverRegistrations
-        const graphData = {}
+      client.on('message', (message) => {
+        if (message === 'requestHistoryGraph') {
+          // Send historical graphData built from all serverRegistrations
+          const graphData = {}
 
-        this.serverRegistrations.forEach((serverRegistration) => {
-          graphData[serverRegistration.serverId] = serverRegistration.graphData
-        })
+          this.serverRegistrations.forEach((serverRegistration) => {
+            graphData[serverRegistration.serverId] = serverRegistration.graphData
+          })
 
-        client.emit('historyGraph', graphData)
+          // Send graphData in object wrapper to avoid needing to explicity filter
+          // any header data being appended by #MessageOf since the graph data is fed
+          // directly into the flot.js graphing system
+          client.send(MessageOf('historyGraph', {
+            graphData: graphData
+          }))
+        }
       })
     }
 
-    client.emit('setPublicConfig', (() => {
-      // Remap minecraftVersion entries into name values
-      const minecraftVersionNames = {}
-      Object.keys(minecraftVersions).forEach(function (key) {
-        minecraftVersionNames[key] = minecraftVersions[key].map(version => version.name)
-      })
+    const initMessage = {
+      config: (() => {
+        // Remap minecraftVersion entries into name values
+        const minecraftVersionNames = {}
+        Object.keys(minecraftVersions).forEach(function (key) {
+          minecraftVersionNames[key] = minecraftVersions[key].map(version => version.name)
+        })
 
-      // Send configuration data for rendering the page
-      return {
-        graphDuration: config.graphDuration,
-        servers: this.serverRegistrations.map(serverRegistration => serverRegistration.data),
-        minecraftVersions: minecraftVersionNames,
-        isGraphVisible: config.logToDatabase
-      }
-    })())
+        // Send configuration data for rendering the page
+        return {
+          graphDuration: config.graphDuration,
+          servers: this.serverRegistrations.map(serverRegistration => serverRegistration.data),
+          minecraftVersions: minecraftVersionNames,
+          isGraphVisible: config.logToDatabase
+        }
+      })(),
+      mojangServices: this.mojangUpdater.getLastUpdate(),
+      servers: this.serverRegistrations.map(serverRegistration => serverRegistration.getPingHistory())
+    }
 
-    // Send last Mojang update, if any
-    this.mojangUpdater.sendLastUpdate(client)
-
-    // Send pingHistory of all ServerRegistrations
-    client.emit('add', this.serverRegistrations.map(serverRegistration => serverRegistration.getPingHistory()))
-
-    // Always send last
-    // This tells the frontend to do final processing and render
-    client.emit('syncComplete')
+    client.send(MessageOf('init', initMessage))
   }
 }
 

lib/message.js

@@ -0,0 +1,6 @@
+module.exports = function MessageOf (name, data) {
+  return JSON.stringify({
+    message: name,
+    ...data
+  })
+}

lib/mojang.js

@@ -1,6 +1,7 @@
 const request = require('request')
 
 const logger = require('./logger')
+const MessageOf = require('./message')
 
 const config = require('../config')
 
@@ -65,14 +66,12 @@ class MojangUpdater {
     if (this._hasUpdated) {
       this._hasUpdated = false
 
-      this._app.server.broadcast('updateMojangServices', this._services)
+      this._app.server.broadcast(MessageOf('updateMojangServices', this._services))
     }
   }
 
-  sendLastUpdate (client) {
-    if (this._services) {
-      client.emit('updateMojangServices', this._services)
-    }
+  getLastUpdate () {
+    return this._services
   }
 
   handleServiceUpdate (url, color) {

lib/ping.js

@@ -4,6 +4,7 @@ const minecraftJavaPing = require('mc-ping-updated')
 const minecraftBedrockPing = require('mcpe-ping-fixed')
 
 const logger = require('./logger')
+const MessageOf = require('./message')
 
 const config = require('../config')
 
@@ -125,7 +126,9 @@ class PingController {
     // Generate a combined update payload
     // This includes any modified fields and flags used by the frontend
     // This will not be cached and can contain live metadata
-    this._app.server.broadcast('update', serverRegistration.getUpdate(timestamp, resp, err, version, updateHistoryGraph))
+    const updateMessage = serverRegistration.getUpdate(timestamp, resp, err, version, updateHistoryGraph)
+
+    this._app.server.broadcast(MessageOf('updateServer', updateMessage))
   }
 }
 

lib/server.js

@@ -1,8 +1,8 @@
 const http = require('http')
 
+const WebSocket = require('ws')
 const finalHttpHandler = require('finalhandler')
 const serveStatic = require('serve-static')
-const io = require('socket.io')
 
 const logger = require('./logger')
 
@@ -12,52 +12,65 @@ function getRemoteAddr (req) {
 
 class Server {
   constructor (clientSocketHandler) {
-    this._clientSocketHandler = clientSocketHandler
-    this._connectedSockets = 0
+    this.createHttpServer()
+    this.createWebSocketServer(clientSocketHandler)
+  }
 
-    this._http = http.createServer(this.handleHttpRequest)
+  createHttpServer () {
+    const distServeStatic = serveStatic('dist/')
+    const faviconsServeStatic = serveStatic('favicons/')
 
-    this._distServeStatic = serveStatic('dist/')
-    this._faviconsServeStatic = serveStatic('favicons/')
+    this._http = http.createServer((req, res) => {
+      logger.log('info', '%s requested: %s', getRemoteAddr(req), req.url)
+
+      // Attempt to handle req using distServeStatic, otherwise fail over to faviconServeStatic
+      // If faviconServeStatic fails, pass to finalHttpHandler to terminate
+      distServeStatic(req, res, () => {
+        faviconsServeStatic(req, res, finalHttpHandler(req, res))
+      })
+    })
+  }
+
+  createWebSocketServer (proxyClientSocketHandler) {
+    this._wss = new WebSocket.Server({
+      server: this._http
+    })
+
+    this._wss.on('connection', (client, req) => {
+      logger.log('info', '%s connected, total clients: %d', getRemoteAddr(req), this.getConnectedClients())
+
+      // Bind disconnect event for logging
+      client.on('close', () => {
+        logger.log('info', '%s disconnected, total clients: %d', getRemoteAddr(req), this.getConnectedClients())
+      })
+
+      // Pass client off to proxy handler
+      proxyClientSocketHandler(client)
+    })
   }
 
   listen (host, port) {
     this._http.listen(port, host)
 
-    this._io = io.listen(this._http)
-    this._io.on('connect', this.handleClientSocket)
-
     logger.log('info', 'Started on %s:%d', host, port)
   }
 
-  broadcast (event, payload) {
-    this._io.sockets.emit(event, payload)
-  }
-
-  handleHttpRequest = (req, res) => {
-    logger.log('info', '%s requested: %s', getRemoteAddr(req), req.url)
-
-    // Attempt to handle req using distServeStatic, otherwise fail over to faviconServeStatic
-    // If faviconServeStatic fails, pass to finalHttpHandler to terminate
-    this._distServeStatic(req, res, () => {
-      this._faviconsServeStatic(req, res, finalHttpHandler(req, res))
+  broadcast (payload) {
+    this._wss.clients.forEach(client => {
+      if (client.readyState === WebSocket.OPEN) {
+        client.send(payload)
+      }
     })
   }
 
-  handleClientSocket = (client) => {
-    this._connectedSockets++
-
-    logger.log('info', '%s connected, total clients: %d', getRemoteAddr(client.request), this._connectedSockets)
-
-    // Bind disconnect event for logging
-    client.on('disconnect', () => {
-      this._connectedSockets--
-
-      logger.log('info', '%s disconnected, total clients: %d', getRemoteAddr(client.request), this._connectedSockets)
+  getConnectedClients () {
+    let count = 0
+    this._wss.clients.forEach(client => {
+      if (client.readyState === WebSocket.OPEN) {
+        count++
+      }
     })
-
-    // Pass client off to proxy handler
-    this._clientSocketHandler(client)
+    return count
   }
 }