kubernetes/vendor/go.etcd.io/etcd/server/v3/etcdserver/api/snap/db.go

var ErrNoDBSnapshot …

// SaveDBFrom saves snapshot of the database from the given reader. It
// guarantees the save operation is atomic.
func (s *Snapshotter) SaveDBFrom(r io.Reader, id uint64) (int64, error) { … }

// DBFilePath returns the file path for the snapshot of the database with
// given id. If the snapshot does not exist, it returns error.
func (s *Snapshotter) DBFilePath(id uint64) (string, error) { … }

func (s *Snapshotter) dbFilePath(id uint64) string { … }