func (store *Store) ReadAt(b []byte, off uint64) (n uint64, err error) {
	store.Lock()
	defer store.Unlock()

	var cnt int
	cnt, err = store.file.ReadAt(b, int64(off))
	n = uint64(cnt)
	return
}
// ReadAt returns the data at the requested location.
ReadAt returns the data at the requested location.
// ReadAt returns the data at the requested location .
func (store *Store) ReadAt(b []byte, off uint64) (n uint64, err error) {
	store.Lock()
	defer store.Unlock()
	var cnt int
	cnt, err = store.file.ReadAt(b, int64(off))
	n = uint64(cnt)
	return
}
func ( store * Store ) ReadAt ( b [ ] byte , off uint64 ) ( n uint64 , err error ) { store . Lock ( ) defer store . Unlock ( ) var cnt int cnt , err = store . file . ReadAt ( b , int64 ( off ) ) n = uint64 ( cnt ) return }
ReadAt returns the data at the requested location.
ReadAt returns the data at the requested location .