constructSetFingerprint function

String constructSetFingerprint(List<ConstructYaml> constructs, { String? sdkVersion, })

Stable identity for a set of constructs (ignores absolute package paths).

Implementation

String constructSetFingerprint(
  List<ConstructYaml> constructs, {
  String? sdkVersion,
}) {
  final parts = <String>[
    for (final yaml in constructs)
      [
        yaml.packageName,
        yaml.packageUri,
        for (final c in yaml.constructs)
          '${c.name}:${c.method}:${c.isServer}:${c.isBuild}:${c.optIn}',
      ].join(';'),
  ]..sort();

  final payload = '${parts.join('|')}|${sdkVersion ?? io.Platform.version}';
  // FNV-1a 64-bit — stable across isolates, no crypto dependency.
  // Use BigInt so the offset/prime are exact (avoid_js_rounded_ints).
  var hash = BigInt.parse('cbf29ce484222325', radix: 16);
  final prime = BigInt.parse('100000001b3', radix: 16);
  final mask = (BigInt.one << 64) - BigInt.one;
  for (final unit in utf8.encode(payload)) {
    hash ^= BigInt.from(unit);
    hash = (hash * prime) & mask;
  }
  return hash.toRadixString(16).padLeft(16, '0');
}