@21epub/epub-thirdparty
Version:
epub-thirdparty
52 lines (51 loc) • 1.55 kB
JavaScript
// prep-work
const _data = new Uint8Array(16);
const _hex = [];
for (let i = 0; i < 256; i++) {
_hex.push(i.toString(16).padStart(2, '0'));
}
// todo@jrieken - with node@15 crypto#getRandomBytes is available everywhere, https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues#browser_compatibility
let _fillRandomValues;
if (typeof crypto === 'object' && typeof crypto.getRandomValues === 'function') {
// browser
_fillRandomValues = crypto.getRandomValues.bind(crypto);
}
else {
_fillRandomValues = function (bucket) {
for (let i = 0; i < bucket.length; i++) {
bucket[i] = Math.floor(Math.random() * 256);
}
return bucket;
};
}
export function generateUuid() {
// get data
_fillRandomValues(_data);
// set version bits
_data[6] = (_data[6] & 0x0f) | 0x40;
_data[8] = (_data[8] & 0x3f) | 0x80;
// print as string
let i = 0;
let result = '';
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += '-';
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += '-';
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += '-';
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += '-';
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += _hex[_data[i++]];
result += _hex[_data[i++]];
return result;
}