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Diffstat (limited to 'node_modules/source-map/lib/base64.js')
-rw-r--r-- | node_modules/source-map/lib/base64.js | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/node_modules/source-map/lib/base64.js b/node_modules/source-map/lib/base64.js new file mode 100644 index 0000000..8aa86b3 --- /dev/null +++ b/node_modules/source-map/lib/base64.js @@ -0,0 +1,67 @@ +/* -*- 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; +}; |