label.hpp

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/*********************************************************************/
// dar - disk archive - a backup/restoration program
// Copyright (C) 2002-2024 Denis Corbin
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// to contact the author, see the AUTHOR file
/*********************************************************************/
 
 
#ifndef LABEL_HPP
#define LABEL_HPP
 
#include "../my_config.h"
 
#include "integers.hpp"
#include "generic_file.hpp"
 
namespace libdar
{
 
 
 
    class label
    {
    public:
    label(); // builds a label equal to 'zero'
    label(const label & ref) { copy_from(ref); };
    label(label && ref) noexcept { move_from(std::move(ref)); };
    label & operator = (const label & ref) { copy_from(ref); return *this; };
    label & operator = (label && ref) noexcept { move_from(std::move(ref)); return *this; };
    ~label() = default;
 
    bool operator == (const label & ref) const;
    bool operator != (const label & ref) const { return ! ((*this) == ref); };
 
    void clear();
    bool is_cleared() const;
 
    void generate_internal_filename();
 
    void read(generic_file & f);
    void dump(generic_file & f) const;
 
    void invert_first_byte() { val[0] = ~val[0]; };
 
        // avoid using these two calls, only here for backward compatibility
        // where the cost to move to object is really too heavy than
        // sticking with a char array.
    U_I size() const { return LABEL_SIZE; };
    char *data() { return (char *)&val; };
    const char *data() const { return (char *)&val; };
 
    static U_I common_size() { return LABEL_SIZE; };
 
    private:
    static constexpr U_I LABEL_SIZE = 10;
 
    char val[LABEL_SIZE];
 
    void copy_from(const label & ref);
    void move_from(label && ref) noexcept;
    };
 
 
    extern const label label_zero;
 
 
} // end of namespace
 
#endif