safe_storage.go

type Storage interface {
	Add(key, val string)
}

type SafeStorage struct {
	storageMu *sync.Mutex
	storage   Storage
}

func NewSafeStorage(storage Storage) *SafeStorage {
	return &SafeStorage{
		storageMu: &sync.Mutex{},
		storage:   storage,
	}
}

func (s *SafeStorage) Add(key, val string) {
	s.storageMu.Lock()
	s.storage.Add(key, val)
	s.storageMu.Unlock()
}