base64-arraybuffer.es5.js 1.9 KB

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  1. /*
  2. * base64-arraybuffer 1.0.1 <https://github.com/niklasvh/base64-arraybuffer>
  3. * Copyright (c) 2022 Niklas von Hertzen <https://hertzen.com>
  4. * Released under MIT License
  5. */
  6. var chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
  7. // Use a lookup table to find the index.
  8. var lookup = typeof Uint8Array === 'undefined' ? [] : new Uint8Array(256);
  9. for (var i = 0; i < chars.length; i++) {
  10. lookup[chars.charCodeAt(i)] = i;
  11. }
  12. var encode = function (arraybuffer) {
  13. var bytes = new Uint8Array(arraybuffer), i, len = bytes.length, base64 = '';
  14. for (i = 0; i < len; i += 3) {
  15. base64 += chars[bytes[i] >> 2];
  16. base64 += chars[((bytes[i] & 3) << 4) | (bytes[i + 1] >> 4)];
  17. base64 += chars[((bytes[i + 1] & 15) << 2) | (bytes[i + 2] >> 6)];
  18. base64 += chars[bytes[i + 2] & 63];
  19. }
  20. if (len % 3 === 2) {
  21. base64 = base64.substring(0, base64.length - 1) + '=';
  22. }
  23. else if (len % 3 === 1) {
  24. base64 = base64.substring(0, base64.length - 2) + '==';
  25. }
  26. return base64;
  27. };
  28. var decode = function (base64) {
  29. var bufferLength = base64.length * 0.75, len = base64.length, i, p = 0, encoded1, encoded2, encoded3, encoded4;
  30. if (base64[base64.length - 1] === '=') {
  31. bufferLength--;
  32. if (base64[base64.length - 2] === '=') {
  33. bufferLength--;
  34. }
  35. }
  36. var arraybuffer = new ArrayBuffer(bufferLength), bytes = new Uint8Array(arraybuffer);
  37. for (i = 0; i < len; i += 4) {
  38. encoded1 = lookup[base64.charCodeAt(i)];
  39. encoded2 = lookup[base64.charCodeAt(i + 1)];
  40. encoded3 = lookup[base64.charCodeAt(i + 2)];
  41. encoded4 = lookup[base64.charCodeAt(i + 3)];
  42. bytes[p++] = (encoded1 << 2) | (encoded2 >> 4);
  43. bytes[p++] = ((encoded2 & 15) << 4) | (encoded3 >> 2);
  44. bytes[p++] = ((encoded3 & 3) << 6) | (encoded4 & 63);
  45. }
  46. return arraybuffer;
  47. };
  48. export { decode, encode };
  49. //# sourceMappingURL=base64-arraybuffer.es5.js.map