/*
 * Copyright (c) 2021 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

export default {

  /**
   * Check obj is empty.
   *
   * @param {object} obj
   * @return {boolean} true(empty)
   */
  isEmpty(obj) {
    return (typeof obj == 'undefined' || obj == null ||
      JSON.stringify(obj) == '{}' || JSON.stringify(obj) == 'undefined');
  },

  /**
   * Check str is empty.
   *
   * @param {string} str
   * @return {boolean} true(empty)
   */
  checkStrIsEmpty(str) {
    return str.trim().length == 0;
  },

  /**
   * Check array is empty.
   *
   * @param {Array}arr
   * @return {boolean} true(empty)
   */
  isEmptyArr(arr) {
    return arr.length == 0;
  },

  // ArrayBuffer转为字符串，参数为ArrayBuffer对象
  ab2str(buf) {
    return String.fromCharCode.apply(null, new Uint8Array(buf));
  },

  // 字符串转为ArrayBuffer对象，参数为字符串
  str2ab(str) {
    var arr = [];
    for (var i = 0, j = str.length; i < j; ++i) {
      arr.push(str.charCodeAt(i));
    }
    var tmpUint8Array = new Uint8Array(arr);
    return tmpUint8Array;
  },

  // 简单阻塞的粗暴实现
  sleep(delay) {
    for (var t = Date.now(); Date.now() - t <= delay;);
  }
}
