Design Patterns: Flyweight Pattern in TypeScript

flyweight-pattern.ts

class UPhoneFlyweight {
  constructor(model: string, screen: number, memory: number) {}
}

class FlyweightFactory {
  public phonesMap: Map<string, UPhoneFlyweight> = new Map();

  public get(model: string, screen: number, memory: number): UPhoneFlyweight {
    const key = model + screen + memory;
    if (!this.phonesMap.has(key)) {
      this.phonesMap.set(key, new UPhoneFlyweight(model, screen, memory));
    }
    return this.phonesMap.get(key)!;
  }
}

class UPhone {
  constructor(flyweight: UPhoneFlyweight, sn: number) {}
}

class UPhoneFactory {
  public static flyweightFactory: FlyweightFactory = new FlyweightFactory();

  public getUPhone(model: string, screen: number, memory: number, sn: number) {
    const flyweight: UPhoneFlyweight = UPhoneFactory.flyweightFactory.get(
      model,
      screen,
      memory
    );
    return new UPhone(flyweight, sn);
  }
}

const uphoneFactory = new UPhoneFactory();

let uphones = [];
for (let i = 0; i < 10000; i++) {
  let memory = i % 2 == 0 ? 64 : 128;
  uphones.push(uphoneFactory.getUPhone("8U", 5.0, memory, i));
}

console.log(
  "UPhoneFlyweight count:",
  UPhoneFactory.flyweightFactory.phonesMap.size
);