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Initial rebrand: @polkadot -> @pezkuwi (14 packages)
- Package namespace: @polkadot/* -> @pezkuwi/* - Repository: polkadot-js/common -> pezkuwichain/pezkuwi-common - Author: Pezkuwi Team <team@pezkuwichain.io> Core packages: - @pezkuwi/util (utilities) - @pezkuwi/util-crypto (crypto primitives) - @pezkuwi/keyring (account management) - @pezkuwi/networks (chain metadata) - @pezkuwi/hw-ledger (Ledger hardware wallet) - @pezkuwi/x-* (10 polyfill packages) Total: 14 packages Upstream: polkadot-js/common v14.0.1
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// Copyright 2017-2025 @polkadot/util authors & contributors
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// SPDX-License-Identifier: Apache-2.0
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import type { ToBn } from '../types.js';
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import { BN } from './bn.js';
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import { BN_MAX_INTEGER, BN_ONE, BN_SQRT_MAX_INTEGER } from './consts.js';
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import { bnToBn } from './toBn.js';
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/**
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* @name bnSqrt
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* @summary Calculates the integer square root of a BN
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* @example
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* <BR>
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*
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* ```javascript
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* import BN from 'bn.js';
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* import { bnSqrt } from '@pezkuwi/util';
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*
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* bnSqrt(new BN(16)).toString(); // => '4'
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* ```
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*/
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export function bnSqrt <ExtToBn extends ToBn> (value: ExtToBn | BN | bigint | string | number | null): BN {
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const n = bnToBn(value);
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if (n.isNeg()) {
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throw new Error('square root of negative numbers is not supported');
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}
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// https://stackoverflow.com/questions/53683995/javascript-big-integer-square-root/
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// shortcut <= 2^53 - 1 to use the JS utils
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if (n.lte(BN_MAX_INTEGER)) {
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// ~~ More performant version of Math.floor
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return new BN(~~Math.sqrt(n.toNumber()));
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}
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// Use sqrt(MAX_SAFE_INTEGER) as starting point. since we already know the
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// output will be larger than this, we expect this to be a safe start
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let x0 = BN_SQRT_MAX_INTEGER.clone();
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while (true) {
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const x1 = n.div(x0).iadd(x0).ishrn(1);
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if (x0.eq(x1) || x0.eq(x1.sub(BN_ONE))) {
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return x0;
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}
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x0 = x1;
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}
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}
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