minixyz/utils/base64.js

  var _PADCHAR = "=",
    _ALPHA = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
    _VERSION = "1.1";//Mr. Ruan fix to 1.1 to support asian char(utf8)


  function _getbyte64(s, i) {
    // This is oddly fast, except on Chrome/V8.
    // Minimal or no improvement in performance by using a
    // object with properties mapping chars to value (eg. 'A': 0)

    var idx = _ALPHA.indexOf(s.charAt(i));

    if (idx === -1) {
      throw "Cannot decode base64";
    }

    return idx;
  }

  function _decode_chars(y, x) {
    while (y.length > 0) {
      var ch = y[0];
      if (ch < 0x80) {
        y.shift();
        x.push(String.fromCharCode(ch));
      } else if ((ch & 0x80) == 0xc0) {
        if (y.length < 2) break;
        ch = y.shift();
        var ch1 = y.shift();
        x.push(String.fromCharCode(((ch & 0x1f) << 6) + (ch1 & 0x3f)));
      } else {
        if (y.length < 3) break;
        ch = y.shift();
        var ch1 = y.shift();
        var ch2 = y.shift();
        x.push(String.fromCharCode(((ch & 0x0f) << 12) + ((ch1 & 0x3f) << 6) + (ch2 & 0x3f)));
      }
    }
  }

  function _decode(s) {
    var pads = 0,
      i,
      b10,
      imax = s.length,
      x = [],
      y = [];

    s = String(s);

    if (imax === 0) {
      return s;
    }

    if (imax % 4 !== 0) {
      throw "Cannot decode base64";
    }

    if (s.charAt(imax - 1) === _PADCHAR) {
      pads = 1;

      if (s.charAt(imax - 2) === _PADCHAR) {
        pads = 2;
      }

      // either way, we want to ignore this last block
      imax -= 4;
    }

    for (i = 0; i < imax; i += 4) {
      var ch1 = _getbyte64(s, i);
      var ch2 = _getbyte64(s, i + 1);
      var ch3 = _getbyte64(s, i + 2);
      var ch4 = _getbyte64(s, i + 3);

      b10 = (_getbyte64(s, i) << 18) | (_getbyte64(s, i + 1) << 12) | (_getbyte64(s, i + 2) << 6) | _getbyte64(s, i + 3);
      y.push(b10 >> 16);
      y.push((b10 >> 8) & 0xff);
      y.push(b10 & 0xff);
      _decode_chars(y, x);
    }
    switch (pads) {
      case 1:
        b10 = (_getbyte64(s, i) << 18) | (_getbyte64(s, i + 1) << 12) | (_getbyte64(s, i + 2) << 6);
        y.push(b10 >> 16);
        y.push((b10 >> 8) & 0xff);
        break;

      case 2:
        b10 = (_getbyte64(s, i) << 18) | (_getbyte64(s, i + 1) << 12);
        y.push(b10 >> 16);
        break;
    }
    _decode_chars(y, x);
    if (y.length > 0) throw "Cannot decode base64";
    return x.join("");
  }


  function _get_chars(ch, y) {
    if (ch < 0x80) y.push(ch);
    else if (ch < 0x800) {
      y.push(0xc0 + ((ch >> 6) & 0x1f));
      y.push(0x80 + (ch & 0x3f));
    } else {
      y.push(0xe0 + ((ch >> 12) & 0xf));
      y.push(0x80 + ((ch >> 6) & 0x3f));
      y.push(0x80 + (ch & 0x3f));
    }
  }



  function _encode(s) {
    if (arguments.length !== 1) {
      throw "SyntaxError: exactly one argument required";
    }

    s = String(s);
    if (s.length === 0) {
      return s;
    }

    //s = _encode_utf8(s);
    var i,
      b10,
      y = [],
      x = [],
      len = s.length;
    i = 0;
    while (i < len) {
      _get_chars(s.charCodeAt(i), y);
      while (y.length >= 3) {
        var ch1 = y.shift();
        var ch2 = y.shift();
        var ch3 = y.shift();
        b10 = (ch1 << 16) | (ch2 << 8) | ch3;
        x.push(_ALPHA.charAt(b10 >> 18));
        x.push(_ALPHA.charAt((b10 >> 12) & 0x3F));
        x.push(_ALPHA.charAt((b10 >> 6) & 0x3f));
        x.push(_ALPHA.charAt(b10 & 0x3f));
      }
      i++;
    }


    switch (y.length) {
      case 1:
        var ch = y.shift();
        b10 = ch << 16;
        x.push(_ALPHA.charAt(b10 >> 18) + _ALPHA.charAt((b10 >> 12) & 0x3F) + _PADCHAR + _PADCHAR);
        break;

      case 2:
        var ch1 = y.shift();
        var ch2 = y.shift();
        b10 = (ch1 << 16) | (ch2 << 8);
        x.push(_ALPHA.charAt(b10 >> 18) + _ALPHA.charAt((b10 >> 12) & 0x3F) + _ALPHA.charAt((b10 >> 6) & 0x3f) + _PADCHAR);
        break;
    }

    return x.join("");
  }


  // return {
  //   decode: _decode,
  //   encode: _encode,
  //   VERSION: _VERSION
  // };

  function transformCode(params) {
    return encodeURIComponent(_encode(params))
  }

export default transformCode