@waku/rln
Version:
RLN (Rate Limiting Nullifier) implementation for Waku
31 lines (29 loc) • 1.18 kB
JavaScript
/**
* Internal helpers for u64. BigUint64Array is too slow as per 2025, so we implement it using Uint32Array.
* @todo re-check https://issues.chromium.org/issues/42212588
* @module
*/
const U32_MASK64 = /* @__PURE__ */ BigInt(2 ** 32 - 1);
const _32n = /* @__PURE__ */ BigInt(32);
function fromBig(n, le = false) {
if (le)
return { h: Number(n & U32_MASK64), l: Number((n >> _32n) & U32_MASK64) };
return { h: Number((n >> _32n) & U32_MASK64) | 0, l: Number(n & U32_MASK64) | 0 };
}
function split(lst, le = false) {
const len = lst.length;
let Ah = new Uint32Array(len);
let Al = new Uint32Array(len);
for (let i = 0; i < len; i++) {
const { h, l } = fromBig(lst[i], le);
[Ah[i], Al[i]] = [h, l];
}
return [Ah, Al];
}
// Left rotate for Shift in [1, 32)
const rotlSH = (h, l, s) => (h << s) | (l >>> (32 - s));
const rotlSL = (h, l, s) => (l << s) | (h >>> (32 - s));
// Left rotate for Shift in (32, 64), NOTE: 32 is special case.
const rotlBH = (h, l, s) => (l << (s - 32)) | (h >>> (64 - s));
const rotlBL = (h, l, s) => (h << (s - 32)) | (l >>> (64 - s));
export { fromBig, rotlBH, rotlBL, rotlSH, rotlSL, split };