@polkadot/util
Version:
A collection of useful utilities for @polkadot
53 lines (52 loc) • 1.63 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.nToU8a = nToU8a;
const x_bigint_1 = require("@polkadot/x-bigint");
const consts_js_1 = require("./consts.js");
const toBigInt_js_1 = require("./toBigInt.js");
const DIV = (0, x_bigint_1.BigInt)(256);
const NEG_MASK = (0, x_bigint_1.BigInt)(0xff);
function toU8a(value, isLe, isNegative) {
const arr = [];
const withSigned = isNegative && (value < consts_js_1._0n);
if (withSigned) {
value = (value + consts_js_1._1n) * -consts_js_1._1n;
}
while (value !== consts_js_1._0n) {
const mod = value % DIV;
const val = Number(withSigned
? mod ^ NEG_MASK
: mod);
if (isLe) {
arr.push(val);
}
else {
arr.unshift(val);
}
value = (value - mod) / DIV;
}
return Uint8Array.from(arr);
}
/**
* @name nToU8a
* @summary Creates a Uint8Array object from a bigint.
*/
function nToU8a(value, { bitLength = -1, isLe = true, isNegative = false } = {}) {
const valueBi = (0, toBigInt_js_1.nToBigInt)(value);
if (valueBi === consts_js_1._0n) {
return bitLength === -1
? new Uint8Array(1)
: new Uint8Array(Math.ceil((bitLength || 0) / 8));
}
const u8a = toU8a(valueBi, isLe, isNegative);
if (bitLength === -1) {
return u8a;
}
const byteLength = Math.ceil((bitLength || 0) / 8);
const output = new Uint8Array(byteLength);
if (isNegative) {
output.fill(0xff);
}
output.set(u8a, isLe ? 0 : byteLength - u8a.length);
return output;
}