73 lines
2.6 KiB
JavaScript
73 lines
2.6 KiB
JavaScript
(function(){
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'use strict';
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let chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_';
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// Use a lookup table to find the index.
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let lookup = new Uint8Array(256);
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for (let i = 0; i < chars.length; i++) {
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lookup[chars.charCodeAt(i)] = i;
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}
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let encode = function(arraybuffer) {
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let bytes = new Uint8Array(arraybuffer),
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i, len = bytes.length, base64url = '';
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for (i = 0; i < len; i+=3) {
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base64url += chars[bytes[i] >> 2];
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base64url += chars[((bytes[i] & 3) << 4) | (bytes[i + 1] >> 4)];
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base64url += chars[((bytes[i + 1] & 15) << 2) | (bytes[i + 2] >> 6)];
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base64url += chars[bytes[i + 2] & 63];
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}
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if ((len % 3) === 2) {
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base64url = base64url.substring(0, base64url.length - 1);
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} else if (len % 3 === 1) {
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base64url = base64url.substring(0, base64url.length - 2);
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}
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return base64url;
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};
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let decode = function(base64string) {
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let bufferLength = base64string.length * 0.75,
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len = base64string.length, i, p = 0,
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encoded1, encoded2, encoded3, encoded4;
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let bytes = new Uint8Array(bufferLength);
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for (i = 0; i < len; i+=4) {
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encoded1 = lookup[base64string.charCodeAt(i)];
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encoded2 = lookup[base64string.charCodeAt(i+1)];
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encoded3 = lookup[base64string.charCodeAt(i+2)];
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encoded4 = lookup[base64string.charCodeAt(i+3)];
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bytes[p++] = (encoded1 << 2) | (encoded2 >> 4);
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bytes[p++] = ((encoded2 & 15) << 4) | (encoded3 >> 2);
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bytes[p++] = ((encoded3 & 3) << 6) | (encoded4 & 63);
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}
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return bytes.buffer
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};
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let methods = {
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'decode': decode,
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'encode': encode
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}
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/**
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* Exporting and stuff
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*/
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if (typeof module !== 'undefined' && typeof module.exports !== 'undefined') {
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module.exports = methods;
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} else {
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if (typeof define === 'function' && define.amd) {
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define([], function() {
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return methods
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});
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} else {
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window.base64url = methods;
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}
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}
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})(); |