heap.hpp

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/*********************************************************************/
// dar - disk archive - a backup/restoration program
// Copyright (C) 2002-2026 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 HEAP_HPP
#define HEAP_HPP
 
#include "../my_config.h"
#include <string>
 
#include "integers.hpp"
#include <memory>
#include <deque>
#if HAVE_LIBTHREADAR_LIBTHREADAR_HPP
#include <libthreadar/libthreadar.hpp>
#endif
 
namespace libdar
{


 
    template <class T> class heap
    {
    public:
    heap() {}; // start with an empty heap
    heap(const heap & ref) = delete;
    heap(heap && ref) = default;
    heap & operator = (const heap & ref) = delete;
    heap & operator = (heap && ref) noexcept = default;
 
    std::unique_ptr<T> get();
    void put(std::unique_ptr<T> && obj);
    void put(std::deque<std::unique_ptr<T> > & list);
    U_I get_size() const { return tas.size(); };
 
    private:
    std::deque<std::unique_ptr<T> > tas;
#ifdef LIBTHREADAR_AVAILABLE
    libthreadar::mutex access;
#endif
    };
 
    template <class T> std::unique_ptr<T> heap<T>::get()
    {
    std::unique_ptr<T> ret;
 
#ifdef LIBTHREADAR_AVAILABLE
    access.lock();
    try
    {
#endif
 
        if(tas.empty())
        throw Erange("heap::get", "heap is empty, it should have be set larger");
 
        ret = std::move(tas.back()); // moving the object pointed to by tas.back() to ret
        tas.pop_back(); // removing the now empty pointer at the end of 'tas'
 
#ifdef LIBTHREADAR_AVAILABLE
    }
    catch(...)
    {
        access.unlock();
        throw;
    }
    access.unlock();
#endif
 
    return ret;
    }
 
    template <class T> void heap<T>::put(std::unique_ptr<T> && obj)
    {
#ifdef LIBTHREADAR_AVAILABLE
    access.lock();
    try
    {
#endif
 
        tas.push_back(std::move(obj));
 
#ifdef LIBTHREADAR_AVAILABLE
    }
    catch(...)
    {
        access.unlock();
        throw;
    }
    access.unlock();
#endif
    }
 
    template <class T> void heap<T>::put(std::deque<std::unique_ptr<T> > & list)
    {
    typename std::deque<std::unique_ptr<T> >::iterator it = list.begin();
 
#ifdef LIBTHREADAR_AVAILABLE
    access.lock();
    try
    {
#endif
 
        while(it != list.end())
        {
        tas.push_back(std::move(*it));
        ++it;
        }
 
#ifdef LIBTHREADAR_AVAILABLE
    }
    catch(...)
    {
        access.unlock();
        throw;
    }
    access.unlock();
#endif
    }

 
} // end of namespace
 
#endif