48 lines
1.6 KiB
JavaScript
48 lines
1.6 KiB
JavaScript
'use strict';
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var $ = require('../internals/export');
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var global = require('../internals/global');
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var uncurryThis = require('../internals/function-uncurry-this');
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var anObjectOrUndefined = require('../internals/an-object-or-undefined');
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var anUint8Array = require('../internals/an-uint8-array');
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var base64Map = require('../internals/base64-map');
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var getAlphabetOption = require('../internals/get-alphabet-option');
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var base64Alphabet = base64Map.i2c;
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var base64UrlAlphabet = base64Map.i2cUrl;
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var Uint8Array = global.Uint8Array;
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var charAt = uncurryThis(''.charAt);
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// `Uint8Array.prototype.toBase64` method
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// https://github.com/tc39/proposal-arraybuffer-base64
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if (Uint8Array) $({ target: 'Uint8Array', proto: true, forced: true }, {
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toBase64: function toBase64(/* options */) {
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var array = anUint8Array(this);
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var options = arguments.length ? anObjectOrUndefined(arguments[0]) : undefined;
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var alphabet = getAlphabetOption(options) === 'base64' ? base64Alphabet : base64UrlAlphabet;
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var result = '';
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var i = 0;
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var length = array.length;
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var triplet;
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var at = function (shift) {
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return charAt(alphabet, (triplet >> (6 * shift)) & 63);
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};
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for (; i + 2 < length; i += 3) {
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triplet = (array[i] << 16) + (array[i + 1] << 8) + array[i + 2];
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result += at(3) + at(2) + at(1) + at(0);
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}
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if (i + 2 === length) {
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triplet = (array[i] << 16) + (array[i + 1] << 8);
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result += at(3) + at(2) + at(1) + '=';
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} else if (i + 1 === length) {
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triplet = array[i] << 16;
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result += at(3) + at(2) + '==';
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}
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return result;
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}
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});
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