}

// logicalRemaining implements fileState.logicalRemaining.
func (fr regFileReader) logicalRemaining() int64 {
	return fr.nb
}

// physicalRemaining implements fileState.physicalRemaining.
func (fr regFileReader) physicalRemaining() int64 {
	return fr.nb
}

// sparseFileReader is a fileReader for reading data from a sparse file entry.
type sparseFileReader struct {

// fileState tracks the number of logical (includes sparse holes) and physical
// (actual in tar archive) bytes remaining for the current file.
//
// Invariant: logicalRemaining >= physicalRemaining
type fileState interface {
	logicalRemaining() int64
	physicalRemaining() int64
}

// allowedFormats determines which formats can be used.
// The value returned is the logical OR of multiple possible formats.