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index.js
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index.js
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'use strict';
(function () {
const magicStr = 'FcwAPNKTMug3GV5Lj7EJnHpWsx4tb8haYeviqBz6rkCy12mUSDQX9RdoZf';
const table = {};
for (let i = 0; i < magicStr.length; i++) table[magicStr[i]] = BigInt(i);
let s = [0, 1, 2, 9, 7, 5, 6, 4, 8, 3, 10, 11];
const BASE = 58n, MAX = (1n << 51n), LEN = 12;
const XOR = 23442827791579n, MASK = 2251799813685247n;
function encode(src) {
if (typeof src !== "bigint") src = BigInt(src);
let r = Array.from('BV1 ');
let it = LEN - 1;
let tmp = (src | MAX) ^ XOR;
while (tmp !== 0n) {
r[s[it]] = magicStr[Number(tmp % BASE)];
tmp /= BASE;
it--;
}
return r.join('');
}
function decode(src) {
let r = 0n;
for (let i = 3; i < LEN; i++) {
r = r * BASE + BigInt(table[src[s[i]]]);
}
return (r & MASK) ^ XOR;
}
window.bvUtil = {encode, decode};
})();