relations_database.hpp

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#ifndef OSMIUM_RELATIONS_RELATIONS_DATABASE_HPP
#define OSMIUM_RELATIONS_RELATIONS_DATABASE_HPP
 
/*
 
This file is part of Osmium (https://osmcode.org/libosmium).
 
Copyright 2013-2023 Jochen Topf <jochen@topf.org> and others (see README).
 
Boost Software License - Version 1.0 - August 17th, 2003
 
Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license (the "Software") to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
do so, all subject to the following:
 
The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
 
*/
 
#include <osmium/osm/relation.hpp>
#include <osmium/storage/item_stash.hpp>
 
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <utility>
#include <vector>
 
namespace osmium {
 
    namespace relations {
 
        class RelationHandle;
 
        class RelationsDatabase {
 
            friend class RelationHandle;
 
            struct element {
 
                osmium::ItemStash::handle_type handle;
 
                std::size_t members;
 
            }; // struct element
 
            osmium::ItemStash& m_stash;
            std::vector<element> m_elements;
 
            osmium::Relation& get_relation(std::size_t pos) {
                assert(pos < m_elements.size());
                return m_stash.get<osmium::Relation>(m_elements[pos].handle);
            }
 
            std::size_t& members(std::size_t pos) noexcept {
                return m_elements[pos].members;
            }
 
            void remove(std::size_t pos) {
                auto& elem = m_elements[pos];
                m_stash.remove_item(elem.handle);
                elem = element{osmium::ItemStash::handle_type{}, 0};
            }
 
        public:
 
            explicit RelationsDatabase(osmium::ItemStash& stash) :
                m_stash(stash) {
            }
 
            std::size_t used_memory() const noexcept {
                return sizeof(element) * m_elements.capacity() +
                       sizeof(RelationsDatabase);
            }
 
            std::size_t size() const noexcept {
                return m_elements.size();
            }
 
            RelationHandle add(const osmium::Relation& relation);
 
            RelationHandle operator[](std::size_t pos) noexcept;
 
            std::size_t count_relations() const noexcept {
                return std::count_if(m_elements.cbegin(), m_elements.cend(), [&](const element& elem) {
                    return elem.handle.valid();
                });
            }
 
            template <typename TFunc>
            void for_each_relation(TFunc&& func);
 
        }; // RelationsDatabase
 
        class RelationHandle {
 
            friend class RelationsDatabase;
 
            RelationsDatabase* m_relation_database;
            std::size_t m_pos;
 
            RelationHandle(RelationsDatabase* relation_database, std::size_t pos) :
                m_relation_database(relation_database),
                m_pos(pos) {
            }
 
        public:
 
            RelationsDatabase* relation_database() const noexcept {
                return m_relation_database;
            }
 
            std::size_t pos() const noexcept {
                return m_pos;
            }
 
            Relation& operator*() {
                return m_relation_database->get_relation(m_pos);
            }
 
            const Relation& operator*() const {
                return m_relation_database->get_relation(m_pos);
            }
 
            Relation* operator->() {
                return &m_relation_database->get_relation(m_pos);
            }
 
            const Relation* operator->() const {
                return &m_relation_database->get_relation(m_pos);
            }
 
            void remove() {
                m_relation_database->remove(pos());
            }
 
            void set_members(std::size_t value) noexcept {
                m_relation_database->members(m_pos) = value;
            }
 
            void increment_members() noexcept {
                ++(m_relation_database->members(m_pos));
            }
 
            void decrement_members() noexcept {
                assert(m_relation_database->members(m_pos) > 0);
                --(m_relation_database->members(m_pos));
            }
 
            bool has_all_members() const noexcept {
                return m_relation_database->members(m_pos) == 0;
            }
 
        }; // class RelationHandle
 
        inline RelationHandle RelationsDatabase::operator[](std::size_t pos) noexcept {
            assert(pos < m_elements.size());
            return {this, pos};
        }
 
        inline RelationHandle RelationsDatabase::add(const osmium::Relation& relation) {
            m_elements.push_back(element{m_stash.add_item(relation), 0});
            return {this, m_elements.size() - 1};
        }
 
        template <typename TFunc>
        void RelationsDatabase::for_each_relation(TFunc&& func) {
            for (std::size_t pos = 0; pos < m_elements.size(); ++pos) {
                if (m_elements[pos].handle.valid()) {
                    func(RelationHandle{this, pos});
                }
            }
        }
 
    } // namespace relations
 
} // namespace osmium
 
#endif // OSMIUM_RELATIONS_RELATIONS_DATABASE_HPP