/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2024 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

#ifndef MAPNIK_MAPPED_MEMORY_CACHE_HPP
#define MAPNIK_MAPPED_MEMORY_CACHE_HPP

// mapnik
#include <mapnik/config.hpp>
#include <mapnik/warning.hpp>
#include <mapnik/util/singleton.hpp>
#include <mapnik/util/noncopyable.hpp>

#include <memory>
#include <string>
#include <unordered_map>
#include <optional>

namespace boost {
namespace interprocess {
class mapped_region;
}
} // namespace boost

namespace mapnik {

using mapped_region_ptr = std::shared_ptr<boost::interprocess::mapped_region>;

class MAPNIK_DECL mapped_memory_cache : public singleton<mapped_memory_cache, CreateStatic>,
                                        private util::noncopyable
{
    friend class CreateStatic<mapped_memory_cache>;
    std::unordered_map<std::string, mapped_region_ptr> cache_;

  public:
    bool insert(std::string const& key, mapped_region_ptr);
    /**
     * @brief removes the resource identified by key from the cache, if exists
     *
     * @param key unique identifier for the resource
     * @return true if the resource was removed
     * @return false if the resource was not removed or wasn't in the cache
     */
    bool remove(std::string const& key);
    std::optional<mapped_region_ptr> find(std::string const& key, bool update_cache = false);
    void clear();
};

MAPNIK_DISABLE_WARNING_PUSH
MAPNIK_DISABLE_WARNING_ATTRIBUTES
extern template class MAPNIK_DECL singleton<mapped_memory_cache, CreateStatic>;
MAPNIK_DISABLE_WARNING_POP

} // namespace mapnik

#endif // MAPNIK_MAPPED_MEMORY_CACHE_HPP
