68 lines
1.9 KiB
JavaScript
Executable File
68 lines
1.9 KiB
JavaScript
Executable File
/*
|
|
* base64-arraybuffer
|
|
* https://github.com/niklasvh/base64-arraybuffer
|
|
*
|
|
* Copyright (c) 2012 Niklas von Hertzen
|
|
* Licensed under the MIT license.
|
|
*/
|
|
(function(){
|
|
"use strict";
|
|
|
|
var chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
|
|
|
|
// Use a lookup table to find the index.
|
|
var lookup = new Uint8Array(256);
|
|
for (var i = 0; i < chars.length; i++) {
|
|
lookup[chars.charCodeAt(i)] = i;
|
|
}
|
|
|
|
exports.encode = function(arraybuffer) {
|
|
var bytes = new Uint8Array(arraybuffer),
|
|
i, len = bytes.length, base64 = "";
|
|
|
|
for (i = 0; i < len; i+=3) {
|
|
base64 += chars[bytes[i] >> 2];
|
|
base64 += chars[((bytes[i] & 3) << 4) | (bytes[i + 1] >> 4)];
|
|
base64 += chars[((bytes[i + 1] & 15) << 2) | (bytes[i + 2] >> 6)];
|
|
base64 += chars[bytes[i + 2] & 63];
|
|
}
|
|
|
|
if ((len % 3) === 2) {
|
|
base64 = base64.substring(0, base64.length - 1) + "=";
|
|
} else if (len % 3 === 1) {
|
|
base64 = base64.substring(0, base64.length - 2) + "==";
|
|
}
|
|
|
|
return base64;
|
|
};
|
|
|
|
exports.decode = function(base64) {
|
|
var bufferLength = base64.length * 0.75,
|
|
len = base64.length, i, p = 0,
|
|
encoded1, encoded2, encoded3, encoded4;
|
|
|
|
if (base64[base64.length - 1] === "=") {
|
|
bufferLength--;
|
|
if (base64[base64.length - 2] === "=") {
|
|
bufferLength--;
|
|
}
|
|
}
|
|
|
|
var arraybuffer = new ArrayBuffer(bufferLength),
|
|
bytes = new Uint8Array(arraybuffer);
|
|
|
|
for (i = 0; i < len; i+=4) {
|
|
encoded1 = lookup[base64.charCodeAt(i)];
|
|
encoded2 = lookup[base64.charCodeAt(i+1)];
|
|
encoded3 = lookup[base64.charCodeAt(i+2)];
|
|
encoded4 = lookup[base64.charCodeAt(i+3)];
|
|
|
|
bytes[p++] = (encoded1 << 2) | (encoded2 >> 4);
|
|
bytes[p++] = ((encoded2 & 15) << 4) | (encoded3 >> 2);
|
|
bytes[p++] = ((encoded3 & 3) << 6) | (encoded4 & 63);
|
|
}
|
|
|
|
return arraybuffer;
|
|
};
|
|
})();
|