default:
		return n, nil
	}
}

func (sw *sparseFileWriter) ReadFrom(r io.Reader) (n int64, err error) {
	rs, ok := r.(io.ReadSeeker)
	if ok {
		if _, err := rs.Seek(0, io.SeekCurrent); err != nil {
			ok = false // Not all io.Seeker can really seek
		}
	}
	if !ok {
		return io.Copy(struct{ io.Writer }{sw}, r)
	}

	var readLastByte bool
	pos0 := sw.pos

		}
	}
}

// Seek wraps syscall.Seek.
func (fd *FD) Seek(offset int64, whence int) (int64, error) {
	if fd.kind == kindPipe {
		return 0, syscall.ESPIPE
	}
	if err := fd.incref(); err != nil {
		return 0, err
	}
	defer fd.decref()

	fd.l.Lock()
	defer fd.l.Unlock()

	return syscall.Seek(fd.Sysfd, offset, whence)
}

	runtime.SetFinalizer(file, nil)
	return err
}

// seek sets the offset for the next Read or Write on file to offset, interpreted
// according to whence: 0 means relative to the origin of the file, 1 means
// relative to the current offset, and 2 means relative to the end.
// It returns the new offset and an error, if any.
func (f *File) seek(offset int64, whence int) (ret int64, err error) {

		file, err := os.OpenFile(filename, os.O_RDWR, 0)
		if err != nil {
			return nil, err
		}
		defer file.Close()

		_, err = file.Seek(0, io.SeekStart)
		if err != nil {
			return nil, err
		}
		_, err = file.WriteString(query)
		if err != nil {
			return nil, err
		}
		_, err = file.Seek(0, io.SeekStart)
		if err != nil {
			return nil, err
		}
		buf := make([]byte, bufSize)
		for {
			n, _ := file.Read(buf)

* `write(daten)`: Schreibt `daten` (`str` oder `bytes`) in die Datei.
* `read(anzahl)`: Liest `anzahl` (`int`) bytes/Zeichen aus der Datei.
* `seek(versatz)`: Geht zur Position `versatz` (`int`) in der Datei.
    * Z. B. würde `await myfile.seek(0)` zum Anfang der Datei gehen.
    * Das ist besonders dann nützlich, wenn Sie `await myfile.read()` einmal ausführen und dann diese Inhalte erneut auslesen müssen.

* `write(data)`: Записать данные `data` (`str` или `bytes`) в файл.
* `read(size)`: Прочитать количество `size` (`int`) байт/символов из файла.
* `seek(offset)`: Перейти к байту на позиции `offset` (`int`) в файле.
    * Наример, `await myfile.seek(0)` перейдет к началу файла.
    * Это особенно удобно, если вы один раз выполнили команду `await myfile.read()`, а затем вам нужно прочитать содержимое файла еще раз.

* `write(data)`: Writes `data` (`str` or `bytes`) to the file.
* `read(size)`: Reads `size` (`int`) bytes/characters of the file.
* `seek(offset)`: Goes to the byte position `offset` (`int`) in the file.
    * E.g., `await myfile.seek(0)` would go to the start of the file.
    * This is especially useful if you run `await myfile.read()` once and then need to read the contents again.
* `close()`: Closes the file.

	runtime.SetFinalizer(file, nil)
	return err
}

// seek sets the offset for the next Read or Write on file to offset, interpreted
// according to whence: 0 means relative to the origin of the file, 1 means
// relative to the current offset, and 2 means relative to the end.
// It returns the new offset and an error, if any.
func (f *File) seek(offset int64, whence int) (ret int64, err error) {

	// exist on disk for until Close is called (at the end of the process).
	Get(ActionID) (Entry, error)

	// Put adds an item to the cache.
	//
	// The seeker is only used to seek to the beginning. After a call to Put,
	// the seek position is not guaranteed to be in any particular state.
	//
	// As a special case, if the ReadSeeker is of type noVerifyReadSeeker,
	// the verification from GODEBUG=goverifycache=1 is skipped.
	//

type Section struct {
	SectionHeader

	// Embed ReaderAt for ReadAt method.
	// Do not embed SectionReader directly
	// to avoid having Read and Seek.
	// If a client wants Read and Seek it must use
	// Open() to avoid fighting over the seek offset
	// with other clients.
	//
	// ReaderAt may be nil if the section is not easily available
	// in a random-access form. For example, a compressed section