cocos-enhance-kit/engine/cocos2d/renderer/memop/recycle-pool.js

import sort from './timsort';

/**
 * Recycle Pool
 * @class RecyclePool
 */
export default class RecyclePool {
  constructor(fn, size) {
    this._fn = fn;
    this._count = 0;
    this._data = new Array(size);

    for (let i = 0; i < size; ++i) {
      this._data[i] = fn();
    }
  }

  get length() {
    return this._count;
  }

  get data() {
    return this._data;
  }

  reset() {
    this._count = 0;
  }

  resize(size) {
    if (size > this._data.length) {
      for (let i = this._data.length; i < size; ++i) {
        this._data[i] = this._fn();
      }
    }
  }

  add() {
    if (this._count >= this._data.length) {
      this.resize(this._data.length * 2);
    }

    return this._data[this._count++];
  }

  remove(idx) {
    if (idx >= this._count) {
      return;
    }

    let last = this._count - 1;
    let tmp = this._data[idx];
    this._data[idx] = this._data[last];
    this._data[last] = tmp;
    this._count -= 1;
  }

  sort(cmp) {
    return sort(this._data, 0, this._count, cmp);
  }
}

cc.RecyclePool = RecyclePool;