text: /**
   * 
   * @param {*} num1 
   * @param {*} num2 
   * @param {*} len 
   * @returns 
   */
  function randomId (num1 = 52, num2 = 2, len = 4) {
      return (Math.random() * Math.pow(num1, num2)).toString(36).slice(len, 10);
  }
  
  /**
   * 
   * @param {*} uid 随机数
   * @returns 
   */
  function fileId (uid) {
      return (parseInt(uid) + Date.now() + Math.random() * Math.pow(52, 10)).toString(16);
  }
  
  /**
   * 
   * @param {*} uid 
   * @returns 
   */
  function shortId (uid) {
      return parseInt(uid + Math.random() * Math.pow(52, 4));
  }
  
  /**
   * 
   * @returns 16位数
   */
  function getUuid() {
      return 'xxxx-xxxx-xxxx-xxxx-xxxx'.replace(/[xy]/g, function (c) {
          var r = Math.random() * 16 | 0,
              v = c == 'x' ? r : (r & 0x3 | 0x8);
          return v.toString(16);
      });
  }
  
  function Guid() {
      var d = new Date().getTime();
      if (globalThis.performance && typeof globalThis.performance.now === "function") {
          d += performance.now(); //use high-precision timer if available
      }
      var uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
          var r = (d + Math.random() * 16) % 16 | 0;
          d = Math.floor(d / 16);
          return (c == 'x' ? r : (r & 0x3 | 0x8)).toString(16);
      });
      return uuid;
  }
  
  // 十进制转64进制
  function str10To64(number) {
      var chars = '0123456789abcdefghigklmnopqrstuvwxyzABCDEFGHIGKLMNOPQRSTUVWXYZ'.split(''),
          radix = chars.length,
          qutient = +number,
          mod = '',
          arr = [];
      do {
          mod = qutient % radix;
          qutient = (qutient - mod) / radix;
          arr.unshift(chars[mod]);
      } while (qutient);
      return arr.join('');
  }
  
  // 十进制转64进制
  function str64To10(number_code) {
      var chars = '0123456789abcdefghigklmnopqrstuvwxyzABCDEFGHIGKLMNOPQRSTUVWXYZ',
          radix = chars.length,
          number_code = String(number_code),
          len = number_code.length,
          i = 0,
          origin_number = 0;
      while (i < len) {
          origin_number += Math.pow(radix, i++) * chars.indexOf(number_code.charAt(len - i) || 0);
      }
      return origin_number;
  }
  
  // 10进制转16进制
  function str10To16(n) {
      typeof n == "string" ? n = Number(n) : ''
      return n.toString(16);
  }
  
  // 16进制转10进制
  function str16To10(n) {
      return Number('0x' + n);
  }
  
  function Base64() {  
  
      // private property  
      _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";  
  
      // public method for encoding  
      this.encode = function (input) {  
          var output = "";  
          var chr1, chr2, chr3, enc1, enc2, enc3, enc4;  
          var i = 0;  
          input = _utf8_encode(input);  
          while (i < input.length) {  
              chr1 = input.charCodeAt(i++);  
              chr2 = input.charCodeAt(i++);  
              chr3 = input.charCodeAt(i++);  
              enc1 = chr1 >> 2;  
              enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);  
              enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);  
              enc4 = chr3 & 63;  
              if (isNaN(chr2)) {  
                  enc3 = enc4 = 64;  
              } else if (isNaN(chr3)) {  
                  enc4 = 64;  
              }  
              output = output +  
              _keyStr.charAt(enc1) + _keyStr.charAt(enc2) +  
              _keyStr.charAt(enc3) + _keyStr.charAt(enc4);  
          }  
          return output;  
      }  
  
      // public method for decoding  
      this.decode = function (input) {  
          var output = "";  
          var chr1, chr2, chr3;  
          var enc1, enc2, enc3, enc4;  
          var i = 0;  
          input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");  
          while (i < input.length) {  
              enc1 = _keyStr.indexOf(input.charAt(i++));  
              enc2 = _keyStr.indexOf(input.charAt(i++));  
              enc3 = _keyStr.indexOf(input.charAt(i++));  
              enc4 = _keyStr.indexOf(input.charAt(i++));  
              chr1 = (enc1 << 2) | (enc2 >> 4);  
              chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);  
              chr3 = ((enc3 & 3) << 6) | enc4;  
              output = output + String.fromCharCode(chr1);  
              if (enc3 != 64) {  
                  output = output + String.fromCharCode(chr2);  
              }  
              if (enc4 != 64) {  
                  output = output + String.fromCharCode(chr3);  
              }  
          }  
          output = _utf8_decode(output);  
          return output;  
      }  
  
      // private method for UTF-8 encoding  
      _utf8_encode = function (string) {  
          string = string.replace(/\r\n/g,"\n");  
          var utftext = "";  
          for (var n = 0; n < string.length; n++) {  
              var c = string.charCodeAt(n);  
              if (c < 128) {  
                  utftext += String.fromCharCode(c);  
              } else if((c > 127) && (c < 2048)) {  
                  utftext += String.fromCharCode((c >> 6) | 192);  
                  utftext += String.fromCharCode((c & 63) | 128);  
              } else {  
                  utftext += String.fromCharCode((c >> 12) | 224);  
                  utftext += String.fromCharCode(((c >> 6) & 63) | 128);  
                  utftext += String.fromCharCode((c & 63) | 128);  
              }  
  
          }  
          return utftext;  
      }  
  
      // private method for UTF-8 decoding  
      _utf8_decode = function (utftext) {  
          var string = "";  
          var i = 0;  
          var c = c1 = c2 = 0;  
          while ( i < utftext.length ) {  
              c = utftext.charCodeAt(i);  
              if (c < 128) {  
                  string += String.fromCharCode(c);  
                  i++;  
              } else if((c > 191) && (c < 224)) {  
                  c2 = utftext.charCodeAt(i+1);  
                  string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));  
                  i += 2;  
              } else {  
                  c2 = utftext.charCodeAt(i+1);  
                  c3 = utftext.charCodeAt(i+2);  
                  string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));  
                  i += 3;  
              }  
          }  
          return string;  
      }  
  }
  
  module.exports = {
      randomId,
      fileId,
      shortId,
      getUuid,
      Guid,
      str10To64,
      str64To10,
      str10To16,
      str16To10,
      Base64
  }