etcd

type DAO interface {
	io.Closer
	Create(key string, entity interface{}) error
	Upsert(key string, entity interface{}) error
	Get(key string, entity interface{}) error
	Query(query Query, slice interface{}) error
	Delete(key string) error
	Watch(ctx context.Context, query Query) (clientv3.WatchChan, error)
	RequestLocker() KeyLocker
}

type Error struct {
	Key  string
	Code int
}

type KeyLocker interface {
	// Lock is creating a lock for the given key
	Lock(key string) error
	// Unlock is removing the lock for the given key
	Unlock(key string)
}

type Query interface {
	Build() (string, error)
}