Pinsave/counterstrike

1/* -*- Mode: js; js-indent-level: 2; -*- */2/*3 * Copyright 2011 Mozilla Foundation and contributors4 * Licensed under the New BSD license. See LICENSE or:5 * http://opensource.org/licenses/BSD-3-Clause6 */7 8var intToCharMap = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'.split('');9 10/**11 * Encode an integer in the range of 0 to 63 to a single base 64 digit.12 */13exports.encode = function (number) {14  if (0 <= number && number < intToCharMap.length) {15    return intToCharMap[number];16  }17  throw new TypeError("Must be between 0 and 63: " + number);18};19 20/**21 * Decode a single base 64 character code digit to an integer. Returns -1 on22 * failure.23 */24exports.decode = function (charCode) {25  var bigA = 65;     // 'A'26  var bigZ = 90;     // 'Z'27 28  var littleA = 97;  // 'a'29  var littleZ = 122; // 'z'30 31  var zero = 48;     // '0'32  var nine = 57;     // '9'33 34  var plus = 43;     // '+'35  var slash = 47;    // '/'36 37  var littleOffset = 26;38  var numberOffset = 52;39 40  // 0 - 25: ABCDEFGHIJKLMNOPQRSTUVWXYZ41  if (bigA <= charCode && charCode <= bigZ) {42    return (charCode - bigA);43  }44 45  // 26 - 51: abcdefghijklmnopqrstuvwxyz46  if (littleA <= charCode && charCode <= littleZ) {47    return (charCode - littleA + littleOffset);48  }49 50  // 52 - 61: 012345678951  if (zero <= charCode && charCode <= nine) {52    return (charCode - zero + numberOffset);53  }54 55  // 62: +56  if (charCode == plus) {57    return 62;58  }59 60  // 63: /61  if (charCode == slash) {62    return 63;63  }64 65  // Invalid base64 digit.66  return -1;67};68