acquire method

@override Future<void> acquire()

Wait until a token is available, then consume it.

Implementation

@override
Future<void> acquire() async {
  while (true) {
    _refill();
    if (_tokens >= 1) {
      _tokens -= 1;
      return;
    }
    final need = 1 - _tokens;
    final waitMs = math.max(10, (need / refillPerSecond * 1000).ceil());
    await Future<void>.delayed(Duration(milliseconds: waitMs));
  }
}