osrm-backend/include/osmium/io/detail/pbf_output_format.hpp

#ifndef OSMIUM_IO_DETAIL_PBF_OUTPUT_FORMAT_HPP
#define OSMIUM_IO_DETAIL_PBF_OUTPUT_FORMAT_HPP

/*

This file is part of Osmium (http://osmcode.org/libosmium).

Copyright 2013-2016 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 <algorithm>
#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <iterator>
#include <memory>
#include <string>
#include <utility>

#include <protozero/pbf_builder.hpp>
#include <protozero/pbf_writer.hpp>
#include <protozero/types.hpp>

#include <osmium/handler.hpp>
#include <osmium/io/detail/output_format.hpp>
#include <osmium/io/detail/pbf.hpp> // IWYU pragma: export
#include <osmium/io/detail/protobuf_tags.hpp>
#include <osmium/io/detail/queue_util.hpp>
#include <osmium/io/detail/string_table.hpp>
#include <osmium/io/detail/zlib.hpp>
#include <osmium/io/file.hpp>
#include <osmium/io/file_format.hpp>
#include <osmium/io/header.hpp>
#include <osmium/memory/buffer.hpp>
#include <osmium/memory/item_iterator.hpp>
#include <osmium/osm/box.hpp>
#include <osmium/osm/item_type.hpp>
#include <osmium/osm/location.hpp>
#include <osmium/osm/node.hpp>
#include <osmium/osm/node_ref.hpp>
#include <osmium/osm/object.hpp>
#include <osmium/osm/relation.hpp>
#include <osmium/osm/tag.hpp>
#include <osmium/osm/timestamp.hpp>
#include <osmium/osm/types.hpp>
#include <osmium/osm/way.hpp>
#include <osmium/thread/pool.hpp>
#include <osmium/util/cast.hpp>
#include <osmium/util/delta.hpp>
#include <osmium/visitor.hpp>

namespace osmium {

    namespace io {

        namespace detail {

            struct pbf_output_options {

                /// Should nodes be encoded in DenseNodes?
                bool use_dense_nodes;

                /**
                 * Should the PBF blobs contain zlib compressed data?
                 *
                 * The zlib compression is optional, it's possible to store the
                 * blobs in raw format. Disabling the compression can improve
                 * the writing speed a little but the output will be 2x to 3x
                 * bigger.
                 */
                bool use_compression;

                /// Should metadata of objects be written?
                bool add_metadata;

                /// Add the "HistoricalInformation" header flag.
                bool add_historical_information_flag;

                /// Should the visible flag be added to all OSM objects?
                bool add_visible_flag;

                /// Should node locations be added to ways?
                bool locations_on_ways;

            };

            /**
             * Maximum number of items in a primitive block.
             *
             * The uncompressed length of a Blob *should* be less
             * than 16 megabytes and *must* be less than 32 megabytes.
             *
             * A block may contain any number of entities, as long as
             * the size limits for the surrounding blob are obeyed.
             * However, for simplicity, the current Osmosis (0.38)
             * as well as Osmium implementation always
             * uses at most 8k entities in a block.
             */
            constexpr int32_t max_entities_per_block = 8000;

            constexpr int location_granularity = 100;

            /**
             * convert a double lat or lon value to an int, respecting the granularity
             */
            inline int64_t lonlat2int(double lonlat) {
                return static_cast<int64_t>(std::round(lonlat * lonlat_resolution / location_granularity));
            }

            enum class pbf_blob_type {
                header = 0,
                data = 1
            };

            class SerializeBlob {

                std::string m_msg;

                pbf_blob_type m_blob_type;

                bool m_use_compression;

            public:

                /**
                 * Initialize a blob serializer.
                 *
                 * @param msg Protobuf-message containing the blob data
                 * @param type Type of blob.
                 * @param use_compression Should the output be compressed using
                 *        zlib?
                 */
                SerializeBlob(std::string&& msg, pbf_blob_type type, bool use_compression) :
                    m_msg(std::move(msg)),
                    m_blob_type(type),
                    m_use_compression(use_compression) {
                }

                /**
                 * Serialize a protobuf message into a Blob, optionally apply
                 * compression and return it together with a BlobHeader ready
                 * to be written to a file.
                 */
                std::string operator()() {
                    assert(m_msg.size() <= max_uncompressed_blob_size);

                    std::string blob_data;
                    protozero::pbf_builder<FileFormat::Blob> pbf_blob(blob_data);

                    if (m_use_compression) {
                        pbf_blob.add_int32(FileFormat::Blob::optional_int32_raw_size, int32_t(m_msg.size()));
                        pbf_blob.add_bytes(FileFormat::Blob::optional_bytes_zlib_data, osmium::io::detail::zlib_compress(m_msg));
                    } else {
                        pbf_blob.add_bytes(FileFormat::Blob::optional_bytes_raw, m_msg);
                    }

                    std::string blob_header_data;
                    protozero::pbf_builder<FileFormat::BlobHeader> pbf_blob_header(blob_header_data);

                    pbf_blob_header.add_string(FileFormat::BlobHeader::required_string_type, m_blob_type == pbf_blob_type::data ? "OSMData" : "OSMHeader");
                    pbf_blob_header.add_int32(FileFormat::BlobHeader::required_int32_datasize, static_cast_with_assert<int32_t>(blob_data.size()));

                    uint32_t sz = htonl(static_cast_with_assert<uint32_t>(blob_header_data.size()));

                    // write to output: the 4-byte BlobHeader-Size followed by the BlobHeader followed by the Blob
                    std::string output;
                    output.reserve(sizeof(sz) + blob_header_data.size() + blob_data.size());
                    output.append(reinterpret_cast<const char*>(&sz), sizeof(sz));
                    output.append(blob_header_data);
                    output.append(blob_data);

                    return output;
                }

            }; // class SerializeBlob

            /**
             * Contains the code to pack any number of nodes into a DenseNode
             * structure.
             *
             * Because this needs to allocate a lot of memory on the heap,
             * only one object of this class will be created and then re-used
             * after calling clear() on it.
             */
            class DenseNodes {

                StringTable& m_stringtable;

                std::vector<int64_t> m_ids;

                std::vector<int32_t> m_versions;
                std::vector<int64_t> m_timestamps;
                std::vector<int64_t> m_changesets;
                std::vector<int32_t> m_uids;
                std::vector<int32_t> m_user_sids;
                std::vector<bool> m_visibles;

                std::vector<int64_t> m_lats;
                std::vector<int64_t> m_lons;
                std::vector<int32_t> m_tags;

                osmium::util::DeltaEncode<object_id_type, int64_t> m_delta_id;

                osmium::util::DeltaEncode<uint32_t, int64_t> m_delta_timestamp;
                osmium::util::DeltaEncode<changeset_id_type, int64_t> m_delta_changeset;
                osmium::util::DeltaEncode<user_id_type, int32_t> m_delta_uid;
                osmium::util::DeltaEncode<uint32_t, int32_t> m_delta_user_sid;

                osmium::util::DeltaEncode<int64_t, int64_t> m_delta_lat;
                osmium::util::DeltaEncode<int64_t, int64_t> m_delta_lon;

                const pbf_output_options& m_options;

            public:

                DenseNodes(StringTable& stringtable, const pbf_output_options& options) :
                    m_stringtable(stringtable),
                    m_options(options) {
                }

                /// Clear object for re-use. Keep the allocated memory.
                void clear() {
                    m_ids.clear();

                    m_versions.clear();
                    m_timestamps.clear();
                    m_changesets.clear();
                    m_uids.clear();
                    m_user_sids.clear();
                    m_visibles.clear();

                    m_lats.clear();
                    m_lons.clear();
                    m_tags.clear();

                    m_delta_id.clear();

                    m_delta_timestamp.clear();
                    m_delta_changeset.clear();
                    m_delta_uid.clear();
                    m_delta_user_sid.clear();

                    m_delta_lat.clear();
                    m_delta_lon.clear();
                }

                size_t size() const {
                    return m_ids.size() * 3 * sizeof(int64_t);
                }

                void add_node(const osmium::Node& node) {
                    m_ids.push_back(m_delta_id.update(node.id()));

                    if (m_options.add_metadata) {
                        m_versions.push_back(static_cast_with_assert<int32_t>(node.version()));
                        m_timestamps.push_back(m_delta_timestamp.update(uint32_t(node.timestamp())));
                        m_changesets.push_back(m_delta_changeset.update(node.changeset()));
                        m_uids.push_back(m_delta_uid.update(node.uid()));
                        m_user_sids.push_back(m_delta_user_sid.update(m_stringtable.add(node.user())));
                        if (m_options.add_visible_flag) {
                            m_visibles.push_back(node.visible());
                        }
                    }

                    m_lats.push_back(m_delta_lat.update(lonlat2int(node.location().lat_without_check())));
                    m_lons.push_back(m_delta_lon.update(lonlat2int(node.location().lon_without_check())));

                    for (const auto& tag : node.tags()) {
                        m_tags.push_back(static_cast_with_assert<int32_t>(m_stringtable.add(tag.key())));
                        m_tags.push_back(static_cast_with_assert<int32_t>(m_stringtable.add(tag.value())));
                    }
                    m_tags.push_back(0);
                }

                std::string serialize() const {
                    std::string data;
                    protozero::pbf_builder<OSMFormat::DenseNodes> pbf_dense_nodes(data);

                    pbf_dense_nodes.add_packed_sint64(OSMFormat::DenseNodes::packed_sint64_id, m_ids.cbegin(), m_ids.cend());

                    if (m_options.add_metadata) {
                        protozero::pbf_builder<OSMFormat::DenseInfo> pbf_dense_info(pbf_dense_nodes, OSMFormat::DenseNodes::optional_DenseInfo_denseinfo);
                        pbf_dense_info.add_packed_int32(OSMFormat::DenseInfo::packed_int32_version, m_versions.cbegin(), m_versions.cend());
                        pbf_dense_info.add_packed_sint64(OSMFormat::DenseInfo::packed_sint64_timestamp, m_timestamps.cbegin(), m_timestamps.cend());
                        pbf_dense_info.add_packed_sint64(OSMFormat::DenseInfo::packed_sint64_changeset, m_changesets.cbegin(), m_changesets.cend());
                        pbf_dense_info.add_packed_sint32(OSMFormat::DenseInfo::packed_sint32_uid, m_uids.cbegin(), m_uids.cend());
                        pbf_dense_info.add_packed_sint32(OSMFormat::DenseInfo::packed_sint32_user_sid, m_user_sids.cbegin(), m_user_sids.cend());

                        if (m_options.add_visible_flag) {
                            pbf_dense_info.add_packed_bool(OSMFormat::DenseInfo::packed_bool_visible, m_visibles.cbegin(), m_visibles.cend());
                        }
                    }

                    pbf_dense_nodes.add_packed_sint64(OSMFormat::DenseNodes::packed_sint64_lat, m_lats.cbegin(), m_lats.cend());
                    pbf_dense_nodes.add_packed_sint64(OSMFormat::DenseNodes::packed_sint64_lon, m_lons.cbegin(), m_lons.cend());

                    pbf_dense_nodes.add_packed_int32(OSMFormat::DenseNodes::packed_int32_keys_vals, m_tags.cbegin(), m_tags.cend());

                    return data;
                }

            }; // class DenseNodes

            class PrimitiveBlock {

                std::string m_pbf_primitive_group_data;
                protozero::pbf_builder<OSMFormat::PrimitiveGroup> m_pbf_primitive_group;
                StringTable m_stringtable;
                DenseNodes m_dense_nodes;
                OSMFormat::PrimitiveGroup m_type;
                int m_count;

            public:

                explicit PrimitiveBlock(const pbf_output_options& options) :
                    m_pbf_primitive_group_data(),
                    m_pbf_primitive_group(m_pbf_primitive_group_data),
                    m_stringtable(),
                    m_dense_nodes(m_stringtable, options),
                    m_type(OSMFormat::PrimitiveGroup::unknown),
                    m_count(0) {
                }

                const std::string& group_data() {
                    if (type() == OSMFormat::PrimitiveGroup::optional_DenseNodes_dense) {
                        m_pbf_primitive_group.add_message(OSMFormat::PrimitiveGroup::optional_DenseNodes_dense, m_dense_nodes.serialize());
                    }
                    return m_pbf_primitive_group_data;
                }

                void reset(OSMFormat::PrimitiveGroup type) {
                    m_pbf_primitive_group_data.clear();
                    m_stringtable.clear();
                    m_dense_nodes.clear();
                    m_type = type;
                    m_count = 0;
                }

                void write_stringtable(protozero::pbf_builder<OSMFormat::StringTable>& pbf_string_table) {
                    for (const char* s : m_stringtable) {
                        pbf_string_table.add_bytes(OSMFormat::StringTable::repeated_bytes_s, s);
                    }
                }

                protozero::pbf_builder<OSMFormat::PrimitiveGroup>& group() {
                    ++m_count;
                    return m_pbf_primitive_group;
                }

                void add_dense_node(const osmium::Node& node) {
                    m_dense_nodes.add_node(node);
                    ++m_count;
                }

                uint32_t store_in_stringtable(const char* s) {
                    return m_stringtable.add(s);
                }

                int count() const {
                    return m_count;
                }

                OSMFormat::PrimitiveGroup type() const {
                    return m_type;
                }

                size_t size() const {
                    return m_pbf_primitive_group_data.size() + m_stringtable.size() + m_dense_nodes.size();
                }

                /**
                 * The output buffer (block) will be filled to about
                 * 95% and then written to disk. This leaves more than
                 * enough space for the string table (which typically
                 * needs about 0.1 to 0.3% of the block size).
                 */
                constexpr static size_t max_used_blob_size = max_uncompressed_blob_size * 95 / 100;

                bool can_add(OSMFormat::PrimitiveGroup type) const {
                    if (type != m_type) {
                        return false;
                    }
                    if (count() >= max_entities_per_block) {
                        return false;
                    }
                    return size() < max_used_blob_size;
                }

            }; // class PrimitiveBlock

            class PBFOutputFormat : public osmium::io::detail::OutputFormat, public osmium::handler::Handler {

                pbf_output_options m_options;

                PrimitiveBlock m_primitive_block;

                void store_primitive_block() {
                    if (m_primitive_block.count() == 0) {
                        return;
                    }

                    std::string primitive_block_data;
                    protozero::pbf_builder<OSMFormat::PrimitiveBlock> primitive_block(primitive_block_data);

                    {
                        protozero::pbf_builder<OSMFormat::StringTable> pbf_string_table(primitive_block, OSMFormat::PrimitiveBlock::required_StringTable_stringtable);
                        m_primitive_block.write_stringtable(pbf_string_table);
                    }

                    primitive_block.add_message(OSMFormat::PrimitiveBlock::repeated_PrimitiveGroup_primitivegroup, m_primitive_block.group_data());

                    m_output_queue.push(osmium::thread::Pool::instance().submit(
                        SerializeBlob{std::move(primitive_block_data),
                                      pbf_blob_type::data,
                                      m_options.use_compression}
                    ));
                }

                template <typename T>
                void add_meta(const osmium::OSMObject& object, T& pbf_object) {
                    {
                        protozero::packed_field_uint32 field{pbf_object, protozero::pbf_tag_type(T::enum_type::packed_uint32_keys)};
                        for (const auto& tag : object.tags()) {
                            field.add_element(m_primitive_block.store_in_stringtable(tag.key()));
                        }
                    }

                    {
                        protozero::packed_field_uint32 field{pbf_object, protozero::pbf_tag_type(T::enum_type::packed_uint32_vals)};
                        for (const auto& tag : object.tags()) {
                            field.add_element(m_primitive_block.store_in_stringtable(tag.value()));
                        }
                    }

                    if (m_options.add_metadata) {
                        protozero::pbf_builder<OSMFormat::Info> pbf_info(pbf_object, T::enum_type::optional_Info_info);

                        pbf_info.add_int32(OSMFormat::Info::optional_int32_version, static_cast_with_assert<int32_t>(object.version()));
                        pbf_info.add_int64(OSMFormat::Info::optional_int64_timestamp, uint32_t(object.timestamp()));
                        pbf_info.add_int64(OSMFormat::Info::optional_int64_changeset, object.changeset());
                        pbf_info.add_int32(OSMFormat::Info::optional_int32_uid, static_cast_with_assert<int32_t>(object.uid()));
                        pbf_info.add_uint32(OSMFormat::Info::optional_uint32_user_sid, m_primitive_block.store_in_stringtable(object.user()));
                        if (m_options.add_visible_flag) {
                            pbf_info.add_bool(OSMFormat::Info::optional_bool_visible, object.visible());
                        }
                    }
                }

                void switch_primitive_block_type(OSMFormat::PrimitiveGroup type) {
                    if (!m_primitive_block.can_add(type)) {
                        store_primitive_block();
                        m_primitive_block.reset(type);
                    }
                }

            public:

                PBFOutputFormat(const osmium::io::File& file, future_string_queue_type& output_queue) :
                    OutputFormat(output_queue),
                    m_options(),
                    m_primitive_block(m_options) {
                    m_options.use_dense_nodes = file.is_not_false("pbf_dense_nodes");
                    m_options.use_compression = file.get("pbf_compression") != "none" && file.is_not_false("pbf_compression");
                    m_options.add_metadata = file.is_not_false("pbf_add_metadata") && file.is_not_false("add_metadata");
                    m_options.add_historical_information_flag = file.has_multiple_object_versions();
                    m_options.add_visible_flag = file.has_multiple_object_versions();
                    m_options.locations_on_ways = file.is_true("locations_on_ways");
                }

                PBFOutputFormat(const PBFOutputFormat&) = delete;
                PBFOutputFormat& operator=(const PBFOutputFormat&) = delete;

                ~PBFOutputFormat() noexcept final = default;

                void write_header(const osmium::io::Header& header) final {
                    std::string data;
                    protozero::pbf_builder<OSMFormat::HeaderBlock> pbf_header_block(data);

                    if (!header.boxes().empty()) {
                        protozero::pbf_builder<OSMFormat::HeaderBBox> pbf_header_bbox(pbf_header_block, OSMFormat::HeaderBlock::optional_HeaderBBox_bbox);

                        osmium::Box box = header.joined_boxes();
                        pbf_header_bbox.add_sint64(OSMFormat::HeaderBBox::required_sint64_left,   int64_t(box.bottom_left().lon() * lonlat_resolution));
                        pbf_header_bbox.add_sint64(OSMFormat::HeaderBBox::required_sint64_right,  int64_t(box.top_right().lon()   * lonlat_resolution));
                        pbf_header_bbox.add_sint64(OSMFormat::HeaderBBox::required_sint64_top,    int64_t(box.top_right().lat()   * lonlat_resolution));
                        pbf_header_bbox.add_sint64(OSMFormat::HeaderBBox::required_sint64_bottom, int64_t(box.bottom_left().lat() * lonlat_resolution));
                    }

                    pbf_header_block.add_string(OSMFormat::HeaderBlock::repeated_string_required_features, "OsmSchema-V0.6");

                    if (m_options.use_dense_nodes) {
                        pbf_header_block.add_string(OSMFormat::HeaderBlock::repeated_string_required_features, "DenseNodes");
                    }

                    if (m_options.add_historical_information_flag) {
                        pbf_header_block.add_string(OSMFormat::HeaderBlock::repeated_string_required_features, "HistoricalInformation");
                    }

                    if (m_options.locations_on_ways) {
                        pbf_header_block.add_string(OSMFormat::HeaderBlock::repeated_string_optional_features, "LocationsOnWays");
                    }

                    pbf_header_block.add_string(OSMFormat::HeaderBlock::optional_string_writingprogram, header.get("generator"));

                    const std::string osmosis_replication_timestamp = header.get("osmosis_replication_timestamp");
                    if (!osmosis_replication_timestamp.empty()) {
                        osmium::Timestamp ts(osmosis_replication_timestamp.c_str());
                        pbf_header_block.add_int64(OSMFormat::HeaderBlock::optional_int64_osmosis_replication_timestamp, uint32_t(ts));
                    }

                    const std::string osmosis_replication_sequence_number = header.get("osmosis_replication_sequence_number");
                    if (!osmosis_replication_sequence_number.empty()) {
                        pbf_header_block.add_int64(OSMFormat::HeaderBlock::optional_int64_osmosis_replication_sequence_number, std::atoll(osmosis_replication_sequence_number.c_str()));
                    }

                    const std::string osmosis_replication_base_url = header.get("osmosis_replication_base_url");
                    if (!osmosis_replication_base_url.empty()) {
                        pbf_header_block.add_string(OSMFormat::HeaderBlock::optional_string_osmosis_replication_base_url, osmosis_replication_base_url);
                    }

                    m_output_queue.push(osmium::thread::Pool::instance().submit(
                        SerializeBlob{std::move(data),
                                      pbf_blob_type::header,
                                      m_options.use_compression}
                        ));
                }

                void write_buffer(osmium::memory::Buffer&& buffer) final {
                    osmium::apply(buffer.cbegin(), buffer.cend(), *this);
                }

                void write_end() final {
                    store_primitive_block();
                }

                void node(const osmium::Node& node) {
                    if (m_options.use_dense_nodes) {
                        switch_primitive_block_type(OSMFormat::PrimitiveGroup::optional_DenseNodes_dense);
                        m_primitive_block.add_dense_node(node);
                        return;
                    }

                    switch_primitive_block_type(OSMFormat::PrimitiveGroup::repeated_Node_nodes);
                    protozero::pbf_builder<OSMFormat::Node> pbf_node{ m_primitive_block.group(), OSMFormat::PrimitiveGroup::repeated_Node_nodes };

                    pbf_node.add_sint64(OSMFormat::Node::required_sint64_id, node.id());
                    add_meta(node, pbf_node);

                    pbf_node.add_sint64(OSMFormat::Node::required_sint64_lat, lonlat2int(node.location().lat_without_check()));
                    pbf_node.add_sint64(OSMFormat::Node::required_sint64_lon, lonlat2int(node.location().lon_without_check()));
                }

                void way(const osmium::Way& way) {
                    switch_primitive_block_type(OSMFormat::PrimitiveGroup::repeated_Way_ways);
                    protozero::pbf_builder<OSMFormat::Way> pbf_way{ m_primitive_block.group(), OSMFormat::PrimitiveGroup::repeated_Way_ways };

                    pbf_way.add_int64(OSMFormat::Way::required_int64_id, way.id());
                    add_meta(way, pbf_way);

                    {
                        osmium::util::DeltaEncode<object_id_type, int64_t> delta_id;
                        protozero::packed_field_sint64 field{pbf_way, protozero::pbf_tag_type(OSMFormat::Way::packed_sint64_refs)};
                        for (const auto& node_ref : way.nodes()) {
                            field.add_element(delta_id.update(node_ref.ref()));
                        }
                    }

                    if (m_options.locations_on_ways) {
                        {
                            osmium::util::DeltaEncode<int64_t, int64_t> delta_id;
                            protozero::packed_field_sint64 field{pbf_way, protozero::pbf_tag_type(OSMFormat::Way::packed_sint64_lon)};
                            for (const auto& node_ref : way.nodes()) {
                                field.add_element(delta_id.update(lonlat2int(node_ref.location().lon_without_check())));
                            }
                        }
                        {
                            osmium::util::DeltaEncode<int64_t, int64_t> delta_id;
                            protozero::packed_field_sint64 field{pbf_way, protozero::pbf_tag_type(OSMFormat::Way::packed_sint64_lat)};
                            for (const auto& node_ref : way.nodes()) {
                                field.add_element(delta_id.update(lonlat2int(node_ref.location().lat_without_check())));
                            }
                        }
                    }
                }

                void relation(const osmium::Relation& relation) {
                    switch_primitive_block_type(OSMFormat::PrimitiveGroup::repeated_Relation_relations);
                    protozero::pbf_builder<OSMFormat::Relation> pbf_relation { m_primitive_block.group(), OSMFormat::PrimitiveGroup::repeated_Relation_relations };

                    pbf_relation.add_int64(OSMFormat::Relation::required_int64_id, relation.id());
                    add_meta(relation, pbf_relation);

                    {
                        protozero::packed_field_int32 field{pbf_relation, protozero::pbf_tag_type(OSMFormat::Relation::packed_int32_roles_sid)};
                        for (const auto& member : relation.members()) {
                            field.add_element(m_primitive_block.store_in_stringtable(member.role()));
                        }
                    }

                    {
                        osmium::util::DeltaEncode<object_id_type, int64_t> delta_id;
                        protozero::packed_field_sint64 field{pbf_relation, protozero::pbf_tag_type(OSMFormat::Relation::packed_sint64_memids)};
                        for (const auto& member : relation.members()) {
                            field.add_element(delta_id.update(member.ref()));
                        }
                    }

                    {
                        protozero::packed_field_int32 field{pbf_relation, protozero::pbf_tag_type(OSMFormat::Relation::packed_MemberType_types)};
                        for (const auto& member : relation.members()) {
                            field.add_element(int32_t(osmium::item_type_to_nwr_index(member.type())));
                        }
                    }
                }

            }; // class PBFOutputFormat

            // we want the register_output_format() function to run, setting
            // the variable is only a side-effect, it will never be used
            const bool registered_pbf_output = osmium::io::detail::OutputFormatFactory::instance().register_output_format(osmium::io::file_format::pbf,
                [](const osmium::io::File& file, future_string_queue_type& output_queue) {
                    return new osmium::io::detail::PBFOutputFormat(file, output_queue);
            });

            // dummy function to silence the unused variable warning from above
            inline bool get_registered_pbf_output() noexcept {
                return registered_pbf_output;
            }

        } // namespace detail

    } // namespace io

} // namespace osmium

#endif // OSMIUM_IO_DETAIL_PBF_OUTPUT_FORMAT_HPP