Improve server performance

src/misc/cache.ts

@@ -0,0 +1,25 @@
+export class Cache<T> {
+	private cache: Map<string | null, { date: number; value: T; }>;
+	private lifetime: number;
+
+	constructor(lifetime: Cache<never>['lifetime']) {
+		this.lifetime = lifetime;
+	}
+
+	public set(key: string | null, value: T):void {
+		this.cache.set(key, {
+			date: Date.now(),
+			value
+		});
+	}
+
+	public get(key: string | null): T | null {
+		const cached = this.cache.get(key);
+		if (cached == null) return null;
+		if ((Date.now() - cached.date) > this.lifetime) {
+			this.cache.delete(key);
+			return null;
+		}
+		return cached.value;
+	}
+}