getExpiredKeys method

@override Future<Stream<String>> getExpiredKeys()

Streams all keys that have expired. The returned Future completes once the backend has accepted the request (surfacing any setup failure eagerly); the Stream then yields the keys.

Implementation

@override
Future<Stream<String>> getExpiredKeys() async {
  // Answered from _expiryIndex — _effectiveExpiry(n) < now is
  // exactly n.isExpired(), without deserialising every entry.
  final now = DateTime.timestamp();
  final expiredKeys = <String>[];
  _expiryIndex.forEach((key, expiry) {
    if (expiry.isBefore(now)) {
      expiredKeys.add(Utf7.encode(key));
    }
  });
  return Stream.fromIterable(expiredKeys);
}