ObjectPool.js

ObjectPool.js

export default class ObjectPool {
  constructor(options = {}) {
    this.options = Object.assign({
      number: 10,
      Create() {
        return {};
      },
    }, options);

    this.available = [];
    this.busy = [];
    this.init();
  }

  init() {
    for (let i = 0; i < this.options.number; i++) {
      const instance = new this.options.Create();

      this.available.push(instance);
    }
  }

  get() {
    if (!this.available.length) {
      throw new Error(`ObjectPool has no more items! default was ${this.number}`);
    }

    const instance = this.available.shift();

    instance._busy = true;
    this.busy.push(instance);

    return instance;
  }

  free(object) {
    const index = this.busy.indexOf(object);

    if (index > -1) {
      object._busy = false;
      this.busy.splice(index, 1);
      this.available.push(object);
    }
  }

  freeAll() {
    this.busy.forEach(object => {
      object._busy = false;
      this.available.push(object);
    });

    this.busy = [];
  }
}