refactor(socket.io): complete rewrite to manage dynamic rooms and seeding better

backend/socket.io/roomEmitter.socket.ts

@@ -1,27 +1,73 @@
 // the emitter setup
+// TODO: validate if we want to add event back in later..
+// let emitFn: ((roomId: string, event: string, payload: unknown) => void) | null =
+// 	null;
 
-import type { RoomId } from "./roomDefinitions.socket.js";
+import { createLogger } from "../logger/logger.controller.js";
 
-let addDataToRoom: ((roomId: RoomId, payload: unknown[]) => void) | null = null;
+type QueuedPayload = unknown;
+
+let emitFn: ((roomId: string, payload: QueuedPayload[]) => void) | null = null;
+
+const queues = new Map<string, QueuedPayload[]>();
+const timers = new Map<string, NodeJS.Timeout>();
+
+const FLUSH_MS = 500;
+const MAX_QUEUE_SIZE = 200;
 
 export const registerEmitter = (
-	fn: (roomId: RoomId, payload: unknown[]) => void,
+	fn: (roomId: string, payload: QueuedPayload) => void,
 ) => {
-	addDataToRoom = fn;
+	emitFn = fn;
 };
 
-export const emitToRoom = (roomId: RoomId, payload: unknown[]) => {
-	if (!addDataToRoom) {
+export const emitToRoom = (roomId: string, payload: QueuedPayload) => {
+	const log = createLogger({ module: "socket.io", subModule: "emitter" });
+	if (!emitFn) {
 		console.error("Socket emitter not initialized");
 		return;
 	}
 
-	addDataToRoom(roomId, payload);
+	const queue = queues.get(roomId) ?? [];
+
+	if (queue.length > MAX_QUEUE_SIZE) {
+		log.error(
+			{ stack: { roomId, size: queue.length }, notify: true },
+			`Socket queue exceeded max size for ${roomId}`,
+		);
+	}
+	queue.push(payload);
+	queues.set(roomId, queue);
+
+	if (timers.has(roomId)) return;
+
+	const timer = setTimeout(() => {
+		try {
+			const payloads = queues.get(roomId) ?? [];
+
+			if (payloads.length === 0) return;
+			emitFn?.(roomId, payloads);
+
+			queues.delete(roomId);
+		} catch (e) {
+			console.error("Socket emit failed", { roomId, e });
+		} finally {
+			timers.delete(roomId);
+		}
+	}, FLUSH_MS);
+
+	timers.set(roomId, timer);
 };
 
 /*
-import { emitToRoom } from "../socket/socketEmitter.js";
-// room name
-// its payload
-emitToRoom("logs", newLogRow);
+example emitToRoom(room, payload)
+
+payload can be anything json serilized example below.
+
+emitToRoom("inventory:ppoo", {
+  type: "snapshot",
+  location: "ppoo",
+  items,
+  createdAt: new Date().toISOString(),
+});
 */