node_modules/source-map/lib/base64.js (raw)
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/* -*- Mode: js; js-indent-level: 2; -*- */ /* * Copyright 2011 Mozilla Foundation and contributors * Licensed under the New BSD license. See LICENSE or: * http://opensource.org/licenses/BSD-3-Clause */ var intToCharMap = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'.split(''); /** * Encode an integer in the range of 0 to 63 to a single base 64 digit. */ exports.encode = function (number) { if (0 <= number && number < intToCharMap.length) { return intToCharMap[number]; } throw new TypeError("Must be between 0 and 63: " + number); }; /** * Decode a single base 64 character code digit to an integer. Returns -1 on * failure. */ exports.decode = function (charCode) { var bigA = 65; // 'A' var bigZ = 90; // 'Z' var littleA = 97; // 'a' var littleZ = 122; // 'z' var zero = 48; // '0' var nine = 57; // '9' var plus = 43; // '+' var slash = 47; // '/' var littleOffset = 26; var numberOffset = 52; // 0 - 25: ABCDEFGHIJKLMNOPQRSTUVWXYZ if (bigA <= charCode && charCode <= bigZ) { return (charCode - bigA); } // 26 - 51: abcdefghijklmnopqrstuvwxyz if (littleA <= charCode && charCode <= littleZ) { return (charCode - littleA + littleOffset); } // 52 - 61: 0123456789 if (zero <= charCode && charCode <= nine) { return (charCode - zero + numberOffset); } // 62: + if (charCode == plus) { return 62; } // 63: / if (charCode == slash) { return 63; } // Invalid base64 digit. return -1; }; |