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utils: optimize hexToBytes by 4%

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Paul Miller 2023-09-25 18:22:57 +00:00
parent f58002e6d4
commit 4752ab1f1e
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1 changed files with 9 additions and 10 deletions
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19
src/abstract/utils.ts
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@ -58,19 +58,18 @@ function asciiToBase16(char: number): number | undefined {
*/
export function hexToBytes(hex: string): Uint8Array {
if (typeof hex !== 'string') throw new Error('hex string expected, got ' + typeof hex);
const len = hex.length;
if (len % 2) throw new Error('padded hex string expected, got unpadded hex of length ' + len);
const al = len / 2;
const hl = hex.length;
const al = hl / 2;
if (hl % 2) throw new Error('padded hex string expected, got unpadded hex of length ' + hl);
const array = new Uint8Array(al);
for (let i = 0, j = 0; i < al; i++) {
const n1 = asciiToBase16(hex.charCodeAt(j++));
const n2 = asciiToBase16(hex.charCodeAt(j++));
for (let ai = 0, hi = 0; ai < al; ai++, hi += 2) {
const n1 = asciiToBase16(hex.charCodeAt(hi));
const n2 = asciiToBase16(hex.charCodeAt(hi + 1));
if (n1 === undefined || n2 === undefined) {
const index = j - 2;
const chr = hex[index] + hex[index + 1];
throw new Error('hex string expected, got non-hex character "' + chr + '" at index ' + index);
const char = hex[hi] + hex[hi + 1];
throw new Error('hex string expected, got non-hex character "' + char + '" at index ' + hi);
}
array[i] = n1 * 16 + n2;
array[ai] = n1 * 16 + n2;
}
return array;
}