app/lib/fingerprint.mjs

Functions

Imports

It imports no other module of this repo. Imported by app/lib/bearer.server.ts, app/lib/content/og-card-text.mjs.

Source

1// A short stable fingerprint shared by the Worker, the build scripts and node tests. The byte encodings (hex, base64)
2// are site-runtime's ./encoding.
3
4/**
5 * FNV-1a, 32 bits, over UTF-16 code units: a short stable fingerprint, not a security boundary.
6 *
7 * @param {string} input
8 * @returns {string} eight lowercase hex digits
9 */
10export function fnv1a32(input) {
11  let hash = 0x811c9dc5;
12  for (let i = 0; i < input.length; i += 1) {
13    hash ^= input.charCodeAt(i);
14    hash = Math.imul(hash, 0x01000193) >>> 0;
15  }
16  return hash.toString(16).padStart(8, "0");
17}