Add etf encoding support with erlpack (#943)

* the performance from this is astounding

* help uws

* save 15 bytes in webpacks

* update readme

* why is markdown like this

* optimizations

* Update WebSocketManager.js

README.md

@@ -27,7 +27,8 @@ Usability and performance are key focuses of discord.js, and it also has nearly
 Without voice support: `npm install discord.js --save`  
 With voice support ([node-opus](https://www.npmjs.com/package/node-opus)): `npm install discord.js node-opus --save`  
 With voice support ([opusscript](https://www.npmjs.com/package/opusscript)): `npm install discord.js opusscript --save`  
-With fast websockets ([uws](https://www.npmjs.com/package/uws)) `npm install discord.js uws --save`
+With a fast websocket client ([uws](https://www.npmjs.com/package/uws)) `npm install discord.js uws --save`  
+With fast websocket encoding ([erlpack](https://github.com/hammerandchisel/erlpack)) `npm install disscord.js hammerandchisel/erlpack --save`
 
 The preferred audio engine is node-opus, as it performs significantly better than opusscript. When both are available, discord.js will automatically choose node-opus.
 Using opusscript is only recommended for development environments where node-opus is tough to get working.

package.json

@@ -37,6 +37,7 @@
     "ws": "^1.1.1"
   },
   "peerDependencies": {
+    "erlpack": "github:hammerandchisel/erlpack",
     "node-opus": "^0.2.0",
     "opusscript": "^0.0.1",
     "uws": "^0.11.1"
@@ -58,6 +59,7 @@
   "browser": {
     "ws": false,
     "uws": false,
+    "erlpack": false,
     "opusscript": false,
     "node-opus": false,
     "tweet-nacl": false,

src/client/rest/RESTMethods.js

@@ -38,7 +38,7 @@ class RESTMethods {
 
   getGateway() {
     return this.rest.makeRequest('get', Constants.Endpoints.gateway, true).then(res => {
-      this.rest.client.ws.gateway = `${res.url}/?encoding=json&v=${Constants.PROTOCOL_VERSION}`;
+      this.rest.client.ws.gateway = `${res.url}/?v=${Constants.PROTOCOL_VERSION}`;
       return this.rest.client.ws.gateway;
     });
   }

src/client/websocket/WebSocketManager.js

@@ -1,6 +1,7 @@
 const browser = typeof window !== 'undefined';
 const EventEmitter = require('events').EventEmitter;
 const Constants = require('../../util/Constants');
+const convertArrayBuffer = require('../../util/ConvertArrayBuffer');
 const pako = require('pako');
 const zlib = require('zlib');
 const PacketManager = require('./packets/WebSocketPacketManager');
@@ -16,6 +17,15 @@ if (browser) {
   }
 }
 
+let erlpack, serialize;
+try {
+  erlpack = require('erlpack');
+  serialize = erlpack.pack;
+} catch (err) {
+  erlpack = null;
+  serialize = JSON.stringify;
+}
+
 /**
  * The WebSocket Manager of the Client
  * @private
@@ -100,6 +110,7 @@ class WebSocketManager extends EventEmitter {
   }
 
   connect(gateway) {
+    gateway = `${gateway}&encoding=${erlpack ? 'etf' : 'json'}`;
     if (this.first) {
       this._connect(gateway);
       this.first = false;
@@ -115,10 +126,10 @@ class WebSocketManager extends EventEmitter {
    */
   send(data, force = false) {
     if (force) {
-      this._send(JSON.stringify(data));
+      this._send(serialize(data));
       return;
     }
-    this._queue.push(JSON.stringify(data));
+    this._queue.push(serialize(data));
     this.doQueue();
   }
 
@@ -240,9 +251,14 @@ class WebSocketManager extends EventEmitter {
    * @returns {Object}
    */
   parseEventData(data) {
-    if (data instanceof ArrayBuffer) data = pako.inflate(data, { to: 'string' });
-    else if (data instanceof Buffer) data = zlib.inflateSync(data).toString();
-    return JSON.parse(data);
+    if (erlpack) {
+      if (data instanceof ArrayBuffer) data = convertArrayBuffer(data);
+      return erlpack.unpack(data);
+    } else {
+      if (data instanceof ArrayBuffer) data = pako.inflate(data, { to: 'string' });
+      else if (data instanceof Buffer) data = zlib.inflateSync(data).toString();
+      return JSON.parse(data);
+    }
   }
 
   /**