range.hpp
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/*********************************************************************/
// dar - disk archive - a backup/restoration program
// Copyright (C) 2002-2023 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 RANGE_HPP
#define RANGE_HPP
#include <string>
#include <set>
#include <list>
#include "../my_config.h"
#include "infinint.hpp"
namespace libdar
{
class range
{
public:
range() { clear(); };
range(const infinint & low, const infinint & high) { parts.push_back(segment(low, high)); };
range(const range & ref) = default;
range(range && ref) noexcept = default;
range & operator = (const range & ref) = default;
range & operator = (range && ref) noexcept = default;
~range() = default;
void operator += (const range & ref);
range operator + (const range & ref) const { range ret = *this; ret += ref; return ret; };
std::string display() const;
void reset_read() const { read_cursor = parts.begin(); };
bool read_next_segment(infinint & low, infinint & high) const;
void clear() { parts.clear(); };
private:
class segment
{
public:
segment(const infinint & x_low, const infinint & x_high) { low = x_low; high = x_high; };
const infinint & get_low() const { return low; };
const infinint & get_high() const { return high; };
bool overlaps_with(const segment & ref) const { return !(ref < *this) && !(ref > *this); };
void merge_with(const segment & ref); // only possible with a segment that overlaps with the current object
// if two segment make < or > true they cannot be replaced by a single segment
bool operator < (const segment & ref) const { return high + 1 < ref.low; };
bool operator > (const segment & ref) const { return ref < *this; };
bool operator == (const segment & ref) const { return ref.high == high && ref.low == low; };
bool operator != (const segment & ref) const { return ! (*this == ref); };
// if two segment make <= or >= true they can be replaced by a single (larger) segment
bool operator <= (const segment & ref) const { return ref.low < low && low <= ref.high + 1 && ref.high < high; };
bool operator >= (const segment &ref) const { return ref <= *this; };
bool contains(const segment & ref) const { return low <= ref.low && ref.high <= high; };
std::string display() const;
private:
infinint low, high;
};
std::list<segment> parts;
mutable std::list<segment>::const_iterator read_cursor;
};
} // end of namespace
#endif
libdar::infinint
the arbitrary large positive integer class
Definition: real_infinint.hpp:62
libdar::range
stores a range of integers or a set of ranges
Definition: range.hpp:44
libdar::range::reset_read
void reset_read() const
provides a way to read range contents segment by segment
Definition: range.hpp:64
libdar::range::read_next_segment
bool read_next_segment(infinint &low, infinint &high) const
read the next available segment
infinint.hpp
switch module to limitint (32 ou 64 bits integers) or infinint
libdar
libdar namespace encapsulate all libdar symbols
Definition: archive.hpp:47