map.hpp

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#ifndef OSMIUM_INDEX_MAP_HPP
#define OSMIUM_INDEX_MAP_HPP
 
/*
 
This file is part of Osmium (https://osmcode.org/libosmium).
 
Copyright 2013-2021 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/util/string.hpp>
 
#include <algorithm>
#include <cstddef>
#include <functional>
#include <map>
#include <memory>
#include <stdexcept>
#include <string>
#include <type_traits>
#include <vector>
 
namespace osmium {
 
    struct map_factory_error : public std::runtime_error {
 
        explicit map_factory_error(const char* message) :
            std::runtime_error(message) {
        }
 
        explicit map_factory_error(const std::string& message) :
            std::runtime_error(message) {
        }
 
    }; // struct map_factory_error
 
    namespace index {
 
        namespace map {
 
            template <typename TId, typename TValue>
            class Map {
 
                              "TId template parameter for class Map must be unsigned integral type");
 
            protected:
 
                Map(Map&&) noexcept = default;
                Map& operator=(Map&&) noexcept = default;
 
            public:
 
                using key_type = TId;
 
                using value_type = TValue;
 
                Map() noexcept = default;
 
                Map(const Map&) = delete;
                Map& operator=(const Map&) = delete;
 
                virtual ~Map() noexcept = default;
 
                virtual void reserve(const std::size_t /*size*/) {
                    // default implementation is empty
                }
 
                virtual void set(const TId id, const TValue value) = 0;
 
                virtual TValue get(const TId id) const = 0;
 
                virtual TValue get_noexcept(const TId id) const noexcept = 0;
 
                virtual std::size_t size() const = 0;
 
                virtual std::size_t used_memory() const = 0;
 
                virtual void clear() = 0;
 
                virtual void sort() {
                    // default implementation is empty
                }
 
                // This function can usually be const in derived classes,
                // but not always. It could, for instance, sort internal data.
                // This is why it is not declared const here.
                virtual void dump_as_list(const int /*fd*/) {
                    throw std::runtime_error{"can't dump as list"};
                }
 
                // This function can usually be const in derived classes,
                // but not always. It could, for instance, sort internal data.
                // This is why it is not declared const here.
                virtual void dump_as_array(const int /*fd*/) {
                    throw std::runtime_error{"can't dump as array"};
                }
 
            }; // class Map
 
        } // namespace map
 
        template <typename TId, typename TValue>
        class MapFactory {
 
        public:
 
            using id_type         = TId;
            using value_type      = TValue;
            using map_type        = osmium::index::map::Map<id_type, value_type>;
            using create_map_func = std::function<map_type*(const std::vector<std::string>&)>;
 
        private:
 
            std::map<const std::string, create_map_func> m_callbacks;
 
            MapFactory() = default;
 
        public:
 
            MapFactory(const MapFactory&) = delete;
            MapFactory& operator=(const MapFactory&) = delete;
 
            MapFactory(MapFactory&&) = delete;
            MapFactory& operator=(MapFactory&&) = delete;
 
            ~MapFactory() = default;
 
            static MapFactory<id_type, value_type>& instance() {
                static MapFactory<id_type, value_type> factory;
                return factory;
            }
 
            bool register_map(const std::string& map_type_name, create_map_func func) {
                return m_callbacks.emplace(map_type_name, func).second;
            }
 
            bool has_map_type(const std::string& map_type_name) const {
                return m_callbacks.count(map_type_name) != 0;
            }
 
            std::vector<std::string> map_types() const {
                std::vector<std::string> result;
 
                for (const auto& cb : m_callbacks) {
                    result.push_back(cb.first);
                }
 
                std::sort(result.begin(), result.end());
 
                return result;
            }
 
            std::unique_ptr<map_type> create_map(const std::string& config_string) const {
                std::vector<std::string> config{osmium::split_string(config_string, ',')};
 
                if (config.empty()) {
                    throw map_factory_error{"Need non-empty map type name"};
                }
 
                const auto it = m_callbacks.find(config[0]);
                if (it != m_callbacks.end()) {
                    return std::unique_ptr<map_type>((it->second)(config));
                }
 
                throw map_factory_error{std::string{"Support for map type '"} + config[0] + "' not compiled into this binary"};
            }
 
        }; // class MapFactory
 
        namespace map {
 
            template <typename TId, typename TValue, template <typename, typename> class TMap>
            struct create_map {
                TMap<TId, TValue>* operator()(const std::vector<std::string>& /*config_string*/) {
                    return new TMap<TId, TValue>();
                }
            };
 
        } // namespace map
 
        template <typename TId, typename TValue, template <typename, typename> class TMap>
        inline bool register_map(const std::string& name) {
            return osmium::index::MapFactory<TId, TValue>::instance().register_map(name, [](const std::vector<std::string>& config) {
                return map::create_map<TId, TValue, TMap>()(config);
            });
        }
 
#define OSMIUM_CONCATENATE_DETAIL_(x, y) x##y
#define OSMIUM_CONCATENATE_(x, y) OSMIUM_CONCATENATE_DETAIL_(x, y)
 
#define REGISTER_MAP(id, value, klass, name) \
namespace osmium { namespace index { namespace detail { \
    namespace OSMIUM_CONCATENATE_(register_map_, __COUNTER__) { \
    const bool registered = osmium::index::register_map<id, value, klass>(#name); \
    inline bool get_registered() noexcept { \
        return registered; \
    } } \
} } }
 
    } // namespace index
 
} // namespace osmium
 
#endif // OSMIUM_INDEX_MAP_HPP