Set with timestamps of when values were added with a purge by age helper

time-set.ts

export class TimeSet {
  private items: Map<string, number>;

  constructor() {
    this.items = new Map();
  }

  add(item: string) {
    const timestamp = Date.now();
    this.items.set(item, timestamp);
  }

  delete(item: string) {
    return this.items.delete(item);
  }

  has(item: string) {
    return this.items.has(item);
  }

  getTimestamp(item: string) {
    return this.items.get(item) || null;
  }

  clear() {
    this.items.clear();
  }

  size() {
    return this.items.size;
  }

  *entries() {
    for (const [item, timestamp] of this.items) {
      yield { item, timestamp };
    }
  }

  *[Symbol.iterator]() {
    yield* this.entries();
  }

  purgeOlderThan(threshold: number) {
    const now = Date.now();
    const result = [];

    for (const [item, timestamp] of this.items) {
      if (now - timestamp > threshold) {
        result.push({ item, timestamp });
        this.items.delete(item);
      }
    }

    return result;
  }
}