/* This Source Code Form is subject to the terms of the Mozilla Public
   * License, v. 2.0. If a copy of the MPL was not distributed with this
   * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  
  // From: http://hg.mozilla.org/mozilla-central/raw-file/ec10630b1a54/js/src/devtools/jint/sunspider/string-base64.js
  
  /*jslint white: false, bitwise: false, plusplus: false */
  /*global console */
  
  var Base64 = {
  
  /* Convert data (an array of integers) to a Base64 string. */
  toBase64Table : 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='.split(''),
  base64Pad     : '=',
  
  encode: function (data) {
      "use strict";
      var result = '';
      var toBase64Table = Base64.toBase64Table;
      var length = data.length
      var lengthpad = (length%3);
      var i = 0, j = 0;
      // Convert every three bytes to 4 ascii characters.
    /* BEGIN LOOP */
      for (i = 0; i < (length - 2); i += 3) {
          result += toBase64Table[data[i] >> 2];
          result += toBase64Table[((data[i] & 0x03) << 4) + (data[i+1] >> 4)];
          result += toBase64Table[((data[i+1] & 0x0f) << 2) + (data[i+2] >> 6)];
          result += toBase64Table[data[i+2] & 0x3f];
      }
    /* END LOOP */
  
      // Convert the remaining 1 or 2 bytes, pad out to 4 characters.
      if (lengthpad === 2) {
          j = length - lengthpad;
          result += toBase64Table[data[j] >> 2];
          result += toBase64Table[((data[j] & 0x03) << 4) + (data[j+1] >> 4)];
          result += toBase64Table[(data[j+1] & 0x0f) << 2];
          result += toBase64Table[64];
      } else if (lengthpad === 1) {
          j = length - lengthpad;
          result += toBase64Table[data[j] >> 2];
          result += toBase64Table[(data[j] & 0x03) << 4];
          result += toBase64Table[64];
          result += toBase64Table[64];
      }
  
      return result;
  },
  
  /* Convert Base64 data to a string */
  toBinaryTable : [
      -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
      -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
      -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
      52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1, 0,-1,-1,
      -1, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,
      15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
      -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
      41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
  ],
  
  decode: function (data, offset) {
      "use strict";
      offset = typeof(offset) !== 'undefined' ? offset : 0;
      var toBinaryTable = Base64.toBinaryTable;
      var base64Pad = Base64.base64Pad;
      var result, result_length, idx, i, c, padding;
      var leftbits = 0; // number of bits decoded, but yet to be appended
      var leftdata = 0; // bits decoded, but yet to be appended
      var data_length = data.indexOf('=') - offset;
  
      if (data_length < 0) { data_length = data.length - offset; }
  
      /* Every four characters is 3 resulting numbers */
      result_length = (data_length >> 2) * 3 + Math.floor((data_length%4)/1.5);
      result = new Array(result_length);
  
      // Convert one by one.
    /* BEGIN LOOP */
      for (idx = 0, i = offset; i < data.length; i++) {
          c = toBinaryTable[data.charCodeAt(i) & 0x7f];
          padding = (data.charAt(i) === base64Pad);
          // Skip illegal characters and whitespace
          if (c === -1) {
              console.error("Illegal character code " + data.charCodeAt(i) + " at position " + i);
              continue;
          }
          
          // Collect data into leftdata, update bitcount
          leftdata = (leftdata << 6) | c;
          leftbits += 6;
  
          // If we have 8 or more bits, append 8 bits to the result
          if (leftbits >= 8) {
              leftbits -= 8;
              // Append if not padding.
              if (!padding) {
                  result[idx++] = (leftdata >> leftbits) & 0xff;
              }
              leftdata &= (1 << leftbits) - 1;
          }
      }
    /* END LOOP */
  
      // If there are any bits left, the base64 string was corrupted
      if (leftbits) {
          throw {name: 'Base64-Error', 
                 message: 'Corrupted base64 string'};
      }
  
      return result;
  }
  
  }; /* End of Base64 namespace */