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/*
* 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;
};
})();
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