From cc67742d3ad81c5474d71fba3172d45c61abcc52 Mon Sep 17 00:00:00 2001
From: Ylian Saint-Hilaire <ysainthilaire@hotmail.com>
Date: Wed, 10 Jun 2020 12:10:32 -0700
Subject: [PATCH] Improved websocket speed for MSTSC.js bitmaps.

---
 mstsc.js                  |  4 ++-
 public/mstsc/js/client.js | 61 ++++++++++++++++++++++-----------------
 2 files changed, 38 insertions(+), 27 deletions(-)

diff --git a/mstsc.js b/mstsc.js
index 3344aebf..74025fd5 100644
--- a/mstsc.js
+++ b/mstsc.js
@@ -84,7 +84,9 @@ module.exports.CreateMstscRelay = function (parent, db, ws, req, args, domain, u
         }).on('connect', function () {
             send(['rdp-connect']);
         }).on('bitmap', function (bitmap) {
-            send(['rdp-bitmap', bitmap]);
+            try { ws.send(bitmap.data); } catch (ex) { } // Send the bitmap data as binary
+            delete bitmap.data;
+            send(['rdp-bitmap', bitmap]); // Send the bitmap metadata seperately, without bitmap data.
         }).on('close', function () {
             send(['rdp-close']);
         }).on('error', function (err) {
diff --git a/public/mstsc/js/client.js b/public/mstsc/js/client.js
index 61842fc4..de9c93ce 100644
--- a/public/mstsc/js/client.js
+++ b/public/mstsc/js/client.js
@@ -129,6 +129,7 @@
 			// start connection
             var self = this;
             this.socket = new WebSocket("wss://" + window.location.host + "/mstsc/relay.ashx");
+            this.socket.binaryType = 'arraybuffer';
             this.socket.onopen = function () {
                 console.log("WS-OPEN");
                 self.socket.send(JSON.stringify(['infos', {
@@ -145,33 +146,41 @@
                 }]));
             };
             this.socket.onmessage = function (evt) {
-                var msg = JSON.parse(evt.data);
-                switch (msg[0]) {
-                    case 'rdp-connect': {
-                        //console.log('[mstsc.js] connected');
-                        self.activeSession = true;
-                        break;
-                    }
-                    case 'rdp-bitmap': {
-                        var bitmap = msg[1];
-                        bitmap.data = new Uint8Array(bitmap.data.data).buffer;
-                        //console.log('[mstsc.js] bitmap update bpp : ' + bitmap.bitsPerPixel);
-                        self.render.update(bitmap);
-                        break;
-                    }
-                    case 'rdp-close': {
-                        //console.log('[mstsc.js] close');
-                        self.activeSession = false;
-                        next(null);
-                        break;
-                    }
-                    case 'rdp-error': {
-                        var err = msg[1];
-                        console.log('[mstsc.js] error : ' + err.code + '(' + err.message + ')');
-                        self.activeSession = false;
-                        next(err);
-                        break;
+                if (typeof evt.data == 'string') {
+                    // This is a JSON text string, parse it.
+                    var msg = JSON.parse(evt.data);
+                    switch (msg[0]) {
+                        case 'rdp-connect': {
+                            //console.log('[mstsc.js] connected');
+                            self.activeSession = true;
+                            break;
+                        }
+                        case 'rdp-bitmap': {
+                            if (self.bitmapData == null) break;
+                            var bitmap = msg[1];
+                            bitmap.data = self.bitmapData; // Use the binary data that was sent earlier.
+                            delete self.bitmapData;
+                            //console.log('[mstsc.js] bitmap update bpp : ' + bitmap.bitsPerPixel);
+                            self.render.update(bitmap);
+                            break;
+                        }
+                        case 'rdp-close': {
+                            //console.log('[mstsc.js] close');
+                            self.activeSession = false;
+                            next(null);
+                            break;
+                        }
+                        case 'rdp-error': {
+                            var err = msg[1];
+                            console.log('[mstsc.js] error : ' + err.code + '(' + err.message + ')');
+                            self.activeSession = false;
+                            next(err);
+                            break;
+                        }
                     }
+                } else {
+                    // This is binary bitmap data, store it.
+                    self.bitmapData = evt.data;
                 }
             };
             this.socket.onclose = function () {