treehouse/static/js/ulid.js

33 lines
876 B
JavaScript
Raw Permalink Normal View History

2024-02-06 20:12:37 +01:00
let canonicalBase32 = "0123456789ABCDEFGHJKMNPQRSTVWXYZ";
let canonicalBase32Rev = {};
for (let i = 0; i < canonicalBase32.length; ++i) {
canonicalBase32Rev[canonicalBase32.charAt(i)] = i;
}
// Works on BigInt to support numbers larger than (1 << 31).
function decodeCanonicalBase32(string) {
let result = 0n;
let cursor = 0b1n;
for (let i = string.length - 1; i >= 0; --i) {
result += cursor * BigInt(canonicalBase32Rev[string[i]]);
cursor <<= 5n;
}
return result;
}
export function getTimestamp(ulid) {
return new Date(Number(decodeCanonicalBase32(ulid.substring(0, 10))));
}
export function isCanonicalUlid(id) {
if (id.length != 26) {
return false;
}
for (let i = 0; i < id.length; ++i) {
if (!canonicalBase32.includes(id.charAt(i))) {
return false;
}
}
return true;
}