WIP: WebSocket connection control

Author: Taulim

.vscode/settings.json

@@ -6,5 +6,6 @@
     "editor.formatOnPaste": false,
     "editor.formatOnType": false,
     "editor.formatOnSave": true,
+    "prettier.singleQuote": true,
     //"editor.formatOnSaveMode": "modifications",
 }

src/index.ts

@@ -1,6 +1,24 @@
-import { serve } from "https://deno.land/std@0.76.0/http/server.ts";
-const s = serve({ port: 8080 });
-console.log("http://localhost:8080/");
-for await (const req of s) {
-	req.respond({ body: "Hello World\n" });
+import { serve } from 'https://deno.land/std@0.76.0/http/server.ts';
+import {
+	acceptable,
+	acceptWebSocket,
+} from 'https://deno.land/std@0.76.0/ws/mod.ts';
+import { HandleWSConn } from './server/WebSocket.ts';
+
+const PORT = 8080;
+const SERVER = serve({ port: PORT });
+console.log(`http://localhost:${PORT}/`);
+
+for await (const req of SERVER) {
+	if (acceptable(req)) {
+		const { conn, headers, r: bufReader, w: bufWriter } = req;
+		acceptWebSocket({ conn, bufReader, bufWriter, headers })
+			.then(HandleWSConn)
+			.catch(async (err: any) => {
+				console.error(`failed to accept websocket: ${err}`);
+				await req.respond({ status: 400 });
+			});
+	} else {
+		req.respond({ body: 'Hello World\n' });
+	}
 }

src/server/Connections.ts

@@ -0,0 +1,56 @@
+import { WebSocket } from 'https://deno.land/std@0.76.0/ws/mod.ts';
+
+type Connection = Readonly<{ id: String; ws: WebSocket }>;
+const Connections: Map<String, WebSocket> = new Map();
+
+export function GetConnections(): Promise<Array<Connection>> {
+	return new Promise((resolve) => {
+		const lConnection: Array<Connection> = [];
+		Connections.forEach((pWebSocket, pId) => {
+			lConnection.push(
+				Object.freeze({
+					id: pId,
+					ws: pWebSocket,
+				})
+			);
+		});
+		resolve(lConnection);
+	});
+}
+
+let id = 0;
+export function AddConn(pWebSocket: WebSocket): Promise<String> {
+	return new Promise((resolve) => {
+		const _id = (id++).toString();
+		Connections.set(_id, pWebSocket);
+		return resolve(_id);
+	});
+}
+
+export function FindConnById(pId: String): Promise<WebSocket | null> {
+	return new Promise((resolve) => {
+		const conn = Connections.get(pId);
+		return resolve(conn ? conn : null);
+	});
+}
+
+export function RemoveConnById(pId: String): Promise<Boolean> {
+	return new Promise((resolve) => {
+		const deleted = Connections.delete(pId);
+		resolve(deleted);
+	});
+}
+
+export function CheckConnById(pId: String): Promise<Boolean> {
+	return new Promise((resolve) => {
+		const conn = Connections.get(pId);
+		const isValid = !(!conn || conn.isClosed);
+		resolve(isValid);
+	});
+}
+
+export function CountConn(): Promise<number> {
+	return new Promise((resolve) => {
+		return resolve(Connections.size);
+	});
+}

src/server/WebSocket.ts

@@ -0,0 +1,51 @@
+import {
+	isWebSocketCloseEvent,
+	isWebSocketPingEvent,
+	WebSocket,
+} from 'https://deno.land/std@0.76.0/ws/mod.ts';
+
+import {
+	GetConnections,
+	AddConn,
+	RemoveConnById,
+	CheckConnById,
+} from './Connections.ts';
+
+export async function HandleWSConn(pWebSocket: WebSocket): Promise<void> {
+	const _connId = await AddConn(pWebSocket);
+	console.log('socket connected!', _connId);
+	try {
+		for await (const event of pWebSocket) {
+			if (typeof event === 'string') {
+				// text message.
+				console.log(`ws:Text = ${event}`);
+				for (const conn of await GetConnections()) {
+					if (_connId !== conn.id && (await CheckConnById(conn.id))) {
+						await conn.ws.send(
+							`Text: ${_connId} -> ${conn.id}: ${event}`
+						);
+					}
+				}
+			} else if (event instanceof Uint8Array) {
+				// binary message.
+				console.log('ws:Binary', event);
+			} else if (isWebSocketPingEvent(event)) {
+				// ping.
+				const [, body] = event;
+				console.log('ws:Ping', _connId, body);
+			} else if (isWebSocketCloseEvent(event)) {
+				// close.
+				const { code, reason } = event;
+				console.log('ws:Close', _connId, code, reason);
+				await RemoveConnById(_connId);
+			} else {
+				console.log('Another type: ', typeof event, event);
+			}
+		}
+	} catch (err) {
+		console.error(`failed to receive frame: ${err}`);
+		if (!pWebSocket.isClosed) {
+			await pWebSocket.close(1000).catch(console.error);
+		}
+	}
+}