| <!DOCTYPE html> |
| <!-- |
| Copyright (c) 2014 The Chromium Authors. All rights reserved. |
| Use of this source code is governed by a BSD-style license that can be |
| found in the LICENSE file. |
| --> |
| <link rel="import" href="/base/base.html"> |
| <script> |
| 'use strict'; |
| |
| tr.exportTo('tr.b', function() { |
| |
| function Base64() { |
| } |
| |
| function b64ToUint6(nChr) { |
| if (nChr > 64 && nChr < 91) |
| return nChr - 65; |
| if (nChr > 96 && nChr < 123) |
| return nChr - 71; |
| if (nChr > 47 && nChr < 58) |
| return nChr + 4; |
| if (nChr === 43) |
| return 62; |
| if (nChr === 47) |
| return 63; |
| return 0; |
| } |
| |
| Base64.getDecodedBufferLength = function(input) { |
| return input.length * 3 + 1 >> 2; |
| } |
| |
| Base64.EncodeArrayBufferToString = function(input) { |
| // http://stackoverflow.com/questions/9267899/ |
| var binary = ''; |
| var bytes = new Uint8Array(input); |
| var len = bytes.byteLength; |
| for (var i = 0; i < len; i++) |
| binary += String.fromCharCode(bytes[i]); |
| return btoa(binary); |
| } |
| |
| Base64.DecodeToTypedArray = function(input, output) { |
| |
| var nInLen = input.length; |
| var nOutLen = nInLen * 3 + 1 >> 2; |
| var nMod3 = 0; |
| var nMod4 = 0; |
| var nUint24 = 0; |
| var nOutIdx = 0; |
| |
| if (nOutLen > output.byteLength) |
| throw new Error('Output buffer too small to decode.'); |
| |
| for (var nInIdx = 0; nInIdx < nInLen; nInIdx++) { |
| nMod4 = nInIdx & 3; |
| nUint24 |= b64ToUint6(input.charCodeAt(nInIdx)) << 18 - 6 * nMod4; |
| if (nMod4 === 3 || nInLen - nInIdx === 1) { |
| for (nMod3 = 0; nMod3 < 3 && nOutIdx < nOutLen; nMod3++, nOutIdx++) { |
| output.setUint8(nOutIdx, nUint24 >>> (16 >>> nMod3 & 24) & 255); |
| } |
| nUint24 = 0; |
| } |
| } |
| return nOutIdx - 1; |
| } |
| |
| return { |
| Base64: Base64 |
| }; |
| |
| }); |
| </script> |
