requestThrottle<T, P> function

Implementation

RequestServiceWrapper<T, P> requestThrottle<T, P>(Duration duration) {
  if (duration < Duration.zero) {
    throw ArgumentError.value(duration, 'duration', 'Cannot be negative.');
  }
  return (next) {
    DateTime? lastStartedAt;
    Future<T>? shared;

    return (params, context) {
      final now = DateTime.now();
      final last = lastStartedAt;
      if (last != null && now.difference(last) < duration && shared != null) {
        return raceCancellation(shared!, context.cancellationToken);
      }
      lastStartedAt = now;
      final future = next(params, context);
      shared = future;
      return future;
    };
  };
}