prev, err := seeker.Seek(0, io.SeekCurrent)
		if err != nil {
			return r.wrapError(0, err)
		}
		end, err := seeker.Seek(0, io.SeekEnd)
		if err != nil {
			return r.wrapError(0, err)
		}
		if prev > end-int64(size) {
			r.blockOffset += end - prev
			return r.makeEOFError(0)
		}

		// The new offset is valid, so seek to it.
		_, err = seeker.Seek(prev+int64(size), io.SeekStart)

	return LineReaderPos{r.buf.off, len(r.fileEntries), r.state, r.fileIndex}
}

// Seek restores the line table reader to a position returned by [LineReader.Tell].
//
// The argument pos must have been returned by a call to [LineReader.Tell] on this
// line table.
func (r *LineReader) Seek(pos LineReaderPos) {
	r.buf.off = pos.off
	r.buf.data = r.section[r.buf.off:r.endOffset]

type Segment struct {
	LoadBytes
	SegmentHeader

	// 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.
	io.ReaderAt
	sr *io.SectionReader
}

// Data reads and returns the contents of the segment.
func (s *Segment) Data() ([]byte, error) {

	return errno
}

// Underlying system call writes to newoffset via pointer.
// Implemented in assembly to avoid allocation.
func seek(fd int, offset int64, whence int) (newoffset int64, err Errno)

func Seek(fd int, offset int64, whence int) (newoffset int64, err error) {
	newoffset, errno := seek(fd, offset, whence)
	if errno != 0 {
		return 0, errno
	}
	return newoffset, nil
}

	for i := len(posTable) - 1; i >= 0; i-- {
		lr.Seek(posTable[i])
		err := lr.Next(&line)
		if i == len(posTable)-1 {
			if err != io.EOF {
				t.Fatal("expected io.EOF after seek to end, got", err)
			}
		} else if err != nil {
			t.Fatal("lr.Next after seek to", posTable[i], "failed:", err)
		} else if line != table[i] {
			t.Fatal("lr.Next after seek to", posTable[i], "returned", line, "instead of", table[i])
		}

	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)
}

    if (frameLength > 0L) {
      source.readFully(controlFrameBuffer, frameLength)

      if (!isClient) {
        controlFrameBuffer.readAndWriteUnsafe(maskCursor!!)
        maskCursor.seek(0)
        toggleMask(maskCursor, maskKey!!)
        maskCursor.close()
      }
    }

    when (opcode) {
      OPCODE_CONTROL_PING -> {

	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)