@polkadot/util/u8a/eq.js

A collection of useful utilities for @polkadot

import { u8aToU8a } from './toU8a.js';
/**
 * @name u8aEq
 * @summary Compares two Uint8Arrays for equality.
 * @description
 * For `UInt8Array` (or hex string) input values true if there is a match.
 * @example
 * <BR>
 *
 * ```javascript
 * import { u8aEq } from '@polkadot/util';
 *
 * u8aEq(new Uint8Array([0x68, 0x65]), new Uint8Array([0x68, 0x65])); // true
 * ```
 */
export function u8aEq(a, b) {
    const u8aa = u8aToU8a(a);
    const u8ab = u8aToU8a(b);
    if (u8aa.length === u8ab.length) {
        const dvA = new DataView(u8aa.buffer, u8aa.byteOffset);
        const dvB = new DataView(u8ab.buffer, u8ab.byteOffset);
        const mod = (u8aa.length % 4) | 0;
        const length = (u8aa.length - mod) | 0;
        for (let i = 0; i < length; i += 4) {
            if (dvA.getUint32(i) !== dvB.getUint32(i)) {
                return false;
            }
        }
        for (let i = length, count = u8aa.length; i < count; i++) {
            if (u8aa[i] !== u8ab[i]) {
                return false;
            }
        }
        return true;
    }
    return false;
}