// ruthlessly stolen from @trunarla on twitter export class LRUCache { #cache: Map>>; #capacity: number; constructor(capacity: number) { this.#capacity = capacity; this.#cache = new Map>>(); } set(key: string, value: string | Record>) { // If we're at capacity, we need to delete the least-recently-used item: if (this.#cache.size >= this.#capacity) { // Manually invoke the keys iterator to get the least-recently-used key: const keyToDelete = this.#cache.keys().next().value; this.#cache.delete(keyToDelete); } this.#cache.delete(key); this.#cache.set(key, value); } get(key: string): Record> | string | undefined { if (this.#cache.has(key)) { const value = this.#cache.get(key); if (!value) return; this.#cache.delete(key); this.#cache.set(key, value); return value; } } }