es.uint8-array.to-base64.js 2.0 KB

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  1. 'use strict';
  2. var $ = require('../internals/export');
  3. var globalThis = require('../internals/global-this');
  4. var uncurryThis = require('../internals/function-uncurry-this');
  5. var anObjectOrUndefined = require('../internals/an-object-or-undefined');
  6. var anUint8Array = require('../internals/an-uint8-array');
  7. var notDetached = require('../internals/array-buffer-not-detached');
  8. var base64Map = require('../internals/base64-map');
  9. var getAlphabetOption = require('../internals/get-alphabet-option');
  10. var base64Alphabet = base64Map.i2c;
  11. var base64UrlAlphabet = base64Map.i2cUrl;
  12. var charAt = uncurryThis(''.charAt);
  13. var Uint8Array = globalThis.Uint8Array;
  14. var INCORRECT_BEHAVIOR_OR_DOESNT_EXISTS = !Uint8Array || !Uint8Array.prototype.toBase64 || !function () {
  15. try {
  16. var target = new Uint8Array();
  17. target.toBase64(null);
  18. } catch (error) {
  19. return true;
  20. }
  21. }();
  22. // `Uint8Array.prototype.toBase64` method
  23. // https://github.com/tc39/proposal-arraybuffer-base64
  24. if (Uint8Array) $({ target: 'Uint8Array', proto: true, forced: INCORRECT_BEHAVIOR_OR_DOESNT_EXISTS }, {
  25. toBase64: function toBase64(/* options */) {
  26. var array = anUint8Array(this);
  27. var options = arguments.length ? anObjectOrUndefined(arguments[0]) : undefined;
  28. var alphabet = getAlphabetOption(options) === 'base64' ? base64Alphabet : base64UrlAlphabet;
  29. var omitPadding = !!options && !!options.omitPadding;
  30. notDetached(this.buffer);
  31. var result = '';
  32. var i = 0;
  33. var length = array.length;
  34. var triplet;
  35. var at = function (shift) {
  36. return charAt(alphabet, (triplet >> (6 * shift)) & 63);
  37. };
  38. for (; i + 2 < length; i += 3) {
  39. triplet = (array[i] << 16) + (array[i + 1] << 8) + array[i + 2];
  40. result += at(3) + at(2) + at(1) + at(0);
  41. }
  42. if (i + 2 === length) {
  43. triplet = (array[i] << 16) + (array[i + 1] << 8);
  44. result += at(3) + at(2) + at(1) + (omitPadding ? '' : '=');
  45. } else if (i + 1 === length) {
  46. triplet = array[i] << 16;
  47. result += at(3) + at(2) + (omitPadding ? '' : '==');
  48. }
  49. return result;
  50. }
  51. });