tag.hpp

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#ifndef OSMIUM_OSM_TAG_HPP
#define OSMIUM_OSM_TAG_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/memory/collection.hpp>
#include <osmium/memory/item.hpp>
#include <osmium/osm/item_type.hpp>
 
#include <algorithm>
#include <cassert>
#include <cstring>
#include <iosfwd>
#include <iterator>
 
namespace osmium {
 
    class Tag : public osmium::memory::detail::ItemHelper {
 
        template <typename TMember>
        friend class osmium::memory::CollectionIterator;
 
        static unsigned char* after_null(unsigned char* ptr) noexcept {
            return reinterpret_cast<unsigned char*>(std::strchr(reinterpret_cast<char*>(ptr), 0) + 1);
        }
 
        static const unsigned char* after_null(const unsigned char* ptr) noexcept {
            return reinterpret_cast<const unsigned char*>(std::strchr(reinterpret_cast<const char*>(ptr), 0) + 1);
        }
 
        unsigned char* next() noexcept {
            return after_null(after_null(data()));
        }
 
        const unsigned char* next() const noexcept {
            return after_null(after_null(data()));
        }
 
    public:
 
        Tag(const Tag&) = delete;
        Tag& operator=(const Tag&) = delete;
 
        Tag(Tag&&) = delete;
        Tag& operator=(Tag&&) = delete;
 
        ~Tag() noexcept = default;
 
        static constexpr item_type collection_type = item_type::tag_list;
 
        const char* key() const noexcept {
            return reinterpret_cast<const char*>(data());
        }
 
        const char* value() const noexcept {
            return reinterpret_cast<const char*>(after_null(data()));
        }
 
    }; // class Tag
 
    inline bool operator==(const Tag& lhs, const Tag& rhs) noexcept {
        return !std::strcmp(lhs.key(), rhs.key()) &&
               !std::strcmp(lhs.value(), rhs.value());
    }
 
    inline bool operator<(const Tag& lhs, const Tag& rhs) noexcept {
        const auto c = std::strcmp(lhs.key(), rhs.key());
        return (c == 0 ? std::strcmp(lhs.value(), rhs.value()) : c) < 0;
    }
 
    template <typename TChar, typename TTraits>
    inline std::basic_ostream<TChar, TTraits>& operator<<(std::basic_ostream<TChar, TTraits>& out, const Tag& tag) {
        return out << tag.key() << '=' << tag.value();
    }
 
    class TagList : public osmium::memory::Collection<Tag, osmium::item_type::tag_list> {
 
        const_iterator find_key(const char* key) const noexcept {
            return std::find_if(cbegin(), cend(), [key](const Tag& tag) {
                return !std::strcmp(tag.key(), key);
            });
        }
 
    public:
 
        TagList() noexcept = default;
 
        const char* get_value_by_key(const char* key, const char* default_value = nullptr) const noexcept {
            assert(key);
            const auto result = find_key(key);
            return result == cend() ? default_value : result->value();
        }
 
        const char* operator[](const char* key) const noexcept {
            return get_value_by_key(key);
        }
 
        bool has_key(const char* key) const noexcept {
            assert(key);
            return find_key(key) != cend();
        }
 
        bool has_tag(const char* key, const char* value) const noexcept {
            assert(key);
            assert(value);
            const auto result = find_key(key);
            return result != cend() && !std::strcmp(result->value(), value);
        }
 
    }; // class TagList
 
 
} // namespace osmium
 
#endif // OSMIUM_OSM_TAG_HPP