func (s3Select *S3Select) Open(rsc io.ReadSeekCloser) error {
	offset, length, err := s3Select.ScanRange.StartLen()
	if err != nil {
		return err
	}
	seekDirection := io.SeekStart
	if offset < 0 {
		seekDirection = io.SeekEnd
	}
	switch s3Select.Input.format {
	case csvFormat:
		_, err = rsc.Seek(offset, seekDirection)
		if err != nil {
			return err
		}

	buf := NewReader(r)
	allocs := testing.AllocsPerRun(100, func() {
		r.Seek(0, io.SeekStart)
		buf.Reset(r)

		_, err := buf.ReadString('\n')
		if err != nil {
			t.Fatal(err)
		}
	})
	if allocs != 1 {
		t.Errorf("Unexpected number of allocations, got %f, want 1", allocs)
	}
}

		for _, list := range cfV1.Pools {
			pools = append(pools, poolArgs{
				args:          list,
				setDriveCount: setDriveCount,
			})
		}
	case "v2":
		cf := config.ServerConfig{}
		cfReader.Seek(0, io.SeekStart)
		if err = yaml.Unmarshal(rd, &cf); err != nil {
			return err
		}

		pools = make([]poolArgs, 0, len(cf.Pools))
		for _, list := range cf.Pools {
			driveCount := list.SetDriveCount

		// Expected size cannot be satisfied for
		// requested offset and length
		file.Close()
		return nil, errFileCorrupt
	}

	if offset > 0 {
		if _, err = file.Seek(offset, io.SeekStart); err != nil {
			file.Close()
			return nil, err
		}
	}
	return &sendFileReader{Reader: io.LimitReader(file, length), Closer: file}, nil
}

// CreateFile - creates the file.