osrm-backend/src/extractor/extraction_containers.cpp

#include "extractor/extraction_containers.hpp"
#include "extractor/extraction_way.hpp"

#include "util/coordinate_calculation.hpp"
#include "util/range_table.hpp"

#include "util/exception.hpp"
#include "util/fingerprint.hpp"
#include "util/io.hpp"
#include "util/lua_util.hpp"
#include "util/simple_logger.hpp"
#include "util/timing_util.hpp"

#include <boost/assert.hpp>
#include <boost/filesystem.hpp>
#include <boost/filesystem/fstream.hpp>
#include <boost/numeric/conversion/cast.hpp>
#include <boost/ref.hpp>

#include <luabind/luabind.hpp>

#include <stxxl/sort>

#include <chrono>
#include <limits>

namespace
{
namespace oe = osrm::extractor;

// Needed for STXXL comparison - STXXL requires max_value(), min_value(), so we can not use
// std::less<OSMNodeId>{}. Anonymous namespace to keep translation unit local.
struct OSMNodeIDSTXXLLess
{
    using value_type = OSMNodeID;
    bool operator()(const value_type left, const value_type right) const { return left < right; }
    value_type max_value() { return MAX_OSM_NODEID; }
    value_type min_value() { return MIN_OSM_NODEID; }
};

struct CmpEdgeByOSMStartID
{
    using value_type = oe::InternalExtractorEdge;
    bool operator()(const value_type &lhs, const value_type &rhs) const
    {
        return lhs.result.osm_source_id < rhs.result.osm_source_id;
    }

    value_type max_value() { return value_type::max_osm_value(); }
    value_type min_value() { return value_type::min_osm_value(); }
};

struct CmpEdgeByOSMTargetID
{
    using value_type = oe::InternalExtractorEdge;
    bool operator()(const value_type &lhs, const value_type &rhs) const
    {
        return lhs.result.osm_target_id < rhs.result.osm_target_id;
    }

    value_type max_value() { return value_type::max_osm_value(); }
    value_type min_value() { return value_type::min_osm_value(); }
};

struct CmpEdgeByInternalSourceTargetAndName
{
    using value_type = oe::InternalExtractorEdge;
    bool operator()(const value_type &lhs, const value_type &rhs) const
    {
        if (lhs.result.source != rhs.result.source)
            return lhs.result.source < rhs.result.source;

        if (lhs.result.target != rhs.result.target)
            return lhs.result.target < rhs.result.target;

        if (lhs.result.source == SPECIAL_NODEID)
            return false;

        if (lhs.result.name_id == rhs.result.name_id)
            return false;

        if (lhs.result.name_id == EMPTY_NAMEID)
            return false;

        if (rhs.result.name_id == EMPTY_NAMEID)
            return true;

        BOOST_ASSERT(!name_offsets.empty() && name_offsets.back() == name_data.size());
        const oe::ExtractionContainers::STXXLNameCharData::const_iterator data = name_data.begin();
        return std::lexicographical_compare(data + name_offsets[lhs.result.name_id],
                                            data + name_offsets[lhs.result.name_id + 1],
                                            data + name_offsets[rhs.result.name_id],
                                            data + name_offsets[rhs.result.name_id + 1]);
    }

    value_type max_value() { return value_type::max_internal_value(); }
    value_type min_value() { return value_type::min_internal_value(); }

    const oe::ExtractionContainers::STXXLNameCharData &name_data;
    const oe::ExtractionContainers::STXXLNameOffsets &name_offsets;
};

}

namespace osrm
{
namespace extractor
{

static const int WRITE_BLOCK_BUFFER_SIZE = 8000;

ExtractionContainers::ExtractionContainers()
{
    // Check if stxxl can be instantiated
    stxxl::vector<unsigned> dummy_vector;

    // Insert three empty strings offsets for name, destination and pronunciation
    name_offsets.push_back(0);
    name_offsets.push_back(0);
    name_offsets.push_back(0);
    // Insert the total length sentinel (corresponds to the next name string offset)
    name_offsets.push_back(0);

    // the offsets have to be initialized with two values, since we have the empty turn string for
    // the first id
    turn_lane_offsets.push_back(0);
    turn_lane_offsets.push_back(0);
}

/**
 * Processes the collected data and serializes it.
 * At this point nodes are still referenced by their OSM id.
 *
 * - map start-end nodes of ways to ways used int restrictions to compute compressed
 *   trippe representation
 * - filter nodes list to nodes that are referenced by ways
 * - merge edges with nodes to include location of start/end points and serialize
 *
 */
void ExtractionContainers::PrepareData(const std::string &output_file_name,
                                       const std::string &restrictions_file_name,
                                       const std::string &name_file_name,
                                       const std::string &turn_lane_file_name,
                                       lua_State *segment_state)
{
    try
    {
        std::ofstream file_out_stream;
        file_out_stream.open(output_file_name.c_str(), std::ios::binary);
        const util::FingerPrint fingerprint = util::FingerPrint::GetValid();
        file_out_stream.write((char *)&fingerprint, sizeof(util::FingerPrint));

        PrepareNodes();
        WriteNodes(file_out_stream);
        PrepareEdges(segment_state);
        WriteEdges(file_out_stream);

        PrepareRestrictions();
        WriteRestrictions(restrictions_file_name);

        WriteCharData(name_file_name);
        WriteTurnLaneMasks(turn_lane_file_name, turn_lane_offsets, turn_lane_masks);
    }
    catch (const std::exception &e)
    {
        std::cerr << "Caught Execption:" << e.what() << std::endl;
    }
}

void ExtractionContainers::WriteTurnLaneMasks(
    const std::string &file_name,
    const stxxl::vector<std::uint32_t> &offsets,
    const stxxl::vector<guidance::TurnLaneType::Mask> &masks) const
{
    util::SimpleLogger().Write() << "Writing turn lane masks...";
    TIMER_START(turn_lane_timer);

    std::ofstream ofs(file_name, std::ios::binary);

    if (!util::serializeVector(ofs, offsets))
    {
        util::SimpleLogger().Write(logWARNING) << "Error while writing.";
        return;
    }

    if (!util::serializeVector(ofs, masks))
    {
        util::SimpleLogger().Write(logWARNING) << "Error while writing.";
        return;
    }

    TIMER_STOP(turn_lane_timer);
    util::SimpleLogger().Write() << "done (" << TIMER_SEC(turn_lane_timer) << ")";
}

void ExtractionContainers::WriteCharData(const std::string &file_name)
{
    std::cout << "[extractor] writing street name index ... " << std::flush;
    TIMER_START(write_index);
    boost::filesystem::ofstream file_stream(file_name, std::ios::binary);

    // transforms in-place name offsets to name lengths
    BOOST_ASSERT(!name_offsets.empty());
    for (auto curr = name_offsets.begin(), next = name_offsets.begin() + 1;
         next != name_offsets.end(); ++curr, ++next)
    {
        *curr = *next - *curr;
    }

    // removes the total length sentinel
    unsigned total_length = name_offsets.back();
    name_offsets.pop_back();

    // builds and writes the index
    util::RangeTable<> index_range(name_offsets);
    file_stream << index_range;

    file_stream.write((char *)&total_length, sizeof(unsigned));

    // write all chars consecutively
    char write_buffer[WRITE_BLOCK_BUFFER_SIZE];
    unsigned buffer_len = 0;

    for (const auto c : name_char_data)
    {
        write_buffer[buffer_len++] = c;

        if (buffer_len >= WRITE_BLOCK_BUFFER_SIZE)
        {
            file_stream.write(write_buffer, WRITE_BLOCK_BUFFER_SIZE);
            buffer_len = 0;
        }
    }

    file_stream.write(write_buffer, buffer_len);

    TIMER_STOP(write_index);
    std::cout << "ok, after " << TIMER_SEC(write_index) << "s" << std::endl;
}

void ExtractionContainers::PrepareNodes()
{
    std::cout << "[extractor] Sorting used nodes        ... " << std::flush;
    TIMER_START(sorting_used_nodes);
    stxxl::sort(
        used_node_id_list.begin(), used_node_id_list.end(), OSMNodeIDSTXXLLess(), stxxl_memory);
    TIMER_STOP(sorting_used_nodes);
    std::cout << "ok, after " << TIMER_SEC(sorting_used_nodes) << "s" << std::endl;

    std::cout << "[extractor] Erasing duplicate nodes   ... " << std::flush;
    TIMER_START(erasing_dups);
    auto new_end = std::unique(used_node_id_list.begin(), used_node_id_list.end());
    used_node_id_list.resize(new_end - used_node_id_list.begin());
    TIMER_STOP(erasing_dups);
    std::cout << "ok, after " << TIMER_SEC(erasing_dups) << "s" << std::endl;

    std::cout << "[extractor] Sorting all nodes         ... " << std::flush;
    TIMER_START(sorting_nodes);
    stxxl::sort(all_nodes_list.begin(),
                all_nodes_list.end(),
                ExternalMemoryNodeSTXXLCompare(),
                stxxl_memory);
    TIMER_STOP(sorting_nodes);
    std::cout << "ok, after " << TIMER_SEC(sorting_nodes) << "s" << std::endl;

    std::cout << "[extractor] Building node id map      ... " << std::flush;
    TIMER_START(id_map);
    external_to_internal_node_id_map.reserve(used_node_id_list.size());
    auto node_iter = all_nodes_list.begin();
    auto ref_iter = used_node_id_list.begin();
    const auto all_nodes_list_end = all_nodes_list.end();
    const auto used_node_id_list_end = used_node_id_list.end();
    // Note: despite being able to handle 64 bit OSM node ids, we can't
    // handle > uint32_t actual usable nodes.  This should be OK for a while
    // because we usually route on a *lot* less than 2^32 of the OSM
    // graph nodes.
    std::uint64_t internal_id = 0;

    // compute the intersection of nodes that were referenced and nodes we actually have
    while (node_iter != all_nodes_list_end && ref_iter != used_node_id_list_end)
    {
        if (node_iter->node_id < *ref_iter)
        {
            node_iter++;
            continue;
        }
        if (node_iter->node_id > *ref_iter)
        {
            ref_iter++;
            continue;
        }
        BOOST_ASSERT(node_iter->node_id == *ref_iter);
        external_to_internal_node_id_map[*ref_iter] = static_cast<NodeID>(internal_id++);
        node_iter++;
        ref_iter++;
    }
    if (internal_id > std::numeric_limits<NodeID>::max())
    {
        throw util::exception("There are too many nodes remaining after filtering, OSRM only "
                              "supports 2^32 unique nodes");
    }
    max_internal_node_id = boost::numeric_cast<NodeID>(internal_id);
    TIMER_STOP(id_map);
    std::cout << "ok, after " << TIMER_SEC(id_map) << "s" << std::endl;
}

void ExtractionContainers::PrepareEdges(lua_State *segment_state)
{
    // Sort edges by start.
    std::cout << "[extractor] Sorting edges by start    ... " << std::flush;
    TIMER_START(sort_edges_by_start);
    stxxl::sort(all_edges_list.begin(), all_edges_list.end(), CmpEdgeByOSMStartID(), stxxl_memory);
    TIMER_STOP(sort_edges_by_start);
    std::cout << "ok, after " << TIMER_SEC(sort_edges_by_start) << "s" << std::endl;

    std::cout << "[extractor] Setting start coords      ... " << std::flush;
    TIMER_START(set_start_coords);
    // Traverse list of edges and nodes in parallel and set start coord
    auto node_iterator = all_nodes_list.begin();
    auto edge_iterator = all_edges_list.begin();

    const auto all_edges_list_end = all_edges_list.end();
    const auto all_nodes_list_end = all_nodes_list.end();

    while (edge_iterator != all_edges_list_end && node_iterator != all_nodes_list_end)
    {
        if (edge_iterator->result.osm_source_id < node_iterator->node_id)
        {
            util::SimpleLogger().Write(LogLevel::logWARNING) << "Found invalid node reference "
                                                             << edge_iterator->result.source;
            edge_iterator->result.source = SPECIAL_NODEID;
            ++edge_iterator;
            continue;
        }
        if (edge_iterator->result.osm_source_id > node_iterator->node_id)
        {
            node_iterator++;
            continue;
        }

        // remove loops
        if (edge_iterator->result.osm_source_id == edge_iterator->result.osm_target_id)
        {
            edge_iterator->result.source = SPECIAL_NODEID;
            edge_iterator->result.target = SPECIAL_NODEID;
            ++edge_iterator;
            continue;
        }

        BOOST_ASSERT(edge_iterator->result.osm_source_id == node_iterator->node_id);

        // assign new node id
        auto id_iter = external_to_internal_node_id_map.find(node_iterator->node_id);
        BOOST_ASSERT(id_iter != external_to_internal_node_id_map.end());
        edge_iterator->result.source = id_iter->second;

        edge_iterator->source_coordinate.lat = node_iterator->lat;
        edge_iterator->source_coordinate.lon = node_iterator->lon;
        ++edge_iterator;
    }

    // Remove all remaining edges. They are invalid because there are no corresponding nodes for
    // them. This happens when using osmosis with bbox or polygon to extract smaller areas.
    auto markSourcesInvalid = [](InternalExtractorEdge &edge) {
        util::SimpleLogger().Write(LogLevel::logWARNING) << "Found invalid node reference "
                                                         << edge.result.source;
        edge.result.source = SPECIAL_NODEID;
        edge.result.osm_source_id = SPECIAL_OSM_NODEID;
    };
    std::for_each(edge_iterator, all_edges_list_end, markSourcesInvalid);
    TIMER_STOP(set_start_coords);
    std::cout << "ok, after " << TIMER_SEC(set_start_coords) << "s" << std::endl;

    // Sort Edges by target
    std::cout << "[extractor] Sorting edges by target   ... " << std::flush;
    TIMER_START(sort_edges_by_target);
    stxxl::sort(all_edges_list.begin(), all_edges_list.end(), CmpEdgeByOSMTargetID(), stxxl_memory);
    TIMER_STOP(sort_edges_by_target);
    std::cout << "ok, after " << TIMER_SEC(sort_edges_by_target) << "s" << std::endl;

    // Compute edge weights
    std::cout << "[extractor] Computing edge weights    ... " << std::flush;
    TIMER_START(compute_weights);
    node_iterator = all_nodes_list.begin();
    edge_iterator = all_edges_list.begin();
    const auto all_edges_list_end_ = all_edges_list.end();
    const auto all_nodes_list_end_ = all_nodes_list.end();

    const auto has_segment_function = util::luaFunctionExists(segment_state, "segment_function");

    while (edge_iterator != all_edges_list_end_ && node_iterator != all_nodes_list_end_)
    {
        // skip all invalid edges
        if (edge_iterator->result.source == SPECIAL_NODEID)
        {
            ++edge_iterator;
            continue;
        }

        if (edge_iterator->result.osm_target_id < node_iterator->node_id)
        {
            util::SimpleLogger().Write(LogLevel::logWARNING)
                << "Found invalid node reference "
                << static_cast<uint64_t>(edge_iterator->result.osm_target_id);
            edge_iterator->result.target = SPECIAL_NODEID;
            ++edge_iterator;
            continue;
        }
        if (edge_iterator->result.osm_target_id > node_iterator->node_id)
        {
            ++node_iterator;
            continue;
        }

        BOOST_ASSERT(edge_iterator->result.osm_target_id == node_iterator->node_id);
        BOOST_ASSERT(edge_iterator->weight_data.speed >= 0);
        BOOST_ASSERT(edge_iterator->source_coordinate.lat !=
                     util::FixedLatitude{std::numeric_limits<std::int32_t>::min()});
        BOOST_ASSERT(edge_iterator->source_coordinate.lon !=
                     util::FixedLongitude{std::numeric_limits<std::int32_t>::min()});

        const double distance = util::coordinate_calculation::greatCircleDistance(
            edge_iterator->source_coordinate,
            util::Coordinate(node_iterator->lon, node_iterator->lat));

        if (has_segment_function)
        {
            luabind::call_function<void>(segment_state,
                                         "segment_function",
                                         boost::cref(edge_iterator->source_coordinate),
                                         boost::cref(*node_iterator),
                                         distance,
                                         boost::ref(edge_iterator->weight_data));
        }

        const double weight = [distance](const InternalExtractorEdge::WeightData &data) {
            switch (data.type)
            {
            case InternalExtractorEdge::WeightType::EDGE_DURATION:
            case InternalExtractorEdge::WeightType::WAY_DURATION:
                return data.duration * 10.;
                break;
            case InternalExtractorEdge::WeightType::SPEED:
                return (distance * 10.) / (data.speed / 3.6);
                break;
            case InternalExtractorEdge::WeightType::INVALID:
                util::exception("invalid weight type");
            }
            return -1.0;
        }(edge_iterator->weight_data);

        auto &edge = edge_iterator->result;
        edge.weight = std::max(1, static_cast<int>(std::floor(weight + .5)));

        // assign new node id
        auto id_iter = external_to_internal_node_id_map.find(node_iterator->node_id);
        BOOST_ASSERT(id_iter != external_to_internal_node_id_map.end());
        edge.target = id_iter->second;

        // orient edges consistently: source id < target id
        // important for multi-edge removal
        if (edge.source > edge.target)
        {
            std::swap(edge.source, edge.target);

            // std::swap does not work with bit-fields
            bool temp = edge.forward;
            edge.forward = edge.backward;
            edge.backward = temp;
        }
        ++edge_iterator;
    }

    // Remove all remaining edges. They are invalid because there are no corresponding nodes for
    // them. This happens when using osmosis with bbox or polygon to extract smaller areas.
    auto markTargetsInvalid = [](InternalExtractorEdge &edge) {
        util::SimpleLogger().Write(LogLevel::logWARNING) << "Found invalid node reference "
                                                         << edge.result.target;
        edge.result.target = SPECIAL_NODEID;
    };
    std::for_each(edge_iterator, all_edges_list_end_, markTargetsInvalid);
    TIMER_STOP(compute_weights);
    std::cout << "ok, after " << TIMER_SEC(compute_weights) << "s" << std::endl;

    // Sort edges by start.
    std::cout << "[extractor] Sorting edges by renumbered start ... " << std::flush;
    TIMER_START(sort_edges_by_renumbered_start);
    stxxl::sort(all_edges_list.begin(),
                all_edges_list.end(),
                CmpEdgeByInternalSourceTargetAndName{name_char_data, name_offsets},
                stxxl_memory);
    TIMER_STOP(sort_edges_by_renumbered_start);
    std::cout << "ok, after " << TIMER_SEC(sort_edges_by_renumbered_start) << "s" << std::endl;

    BOOST_ASSERT(all_edges_list.size() > 0);
    for (unsigned i = 0; i < all_edges_list.size();)
    {
        // only invalid edges left
        if (all_edges_list[i].result.source == SPECIAL_NODEID)
        {
            break;
        }
        // skip invalid edges
        if (all_edges_list[i].result.target == SPECIAL_NODEID)
        {
            ++i;
            continue;
        }

        unsigned start_idx = i;
        NodeID source = all_edges_list[i].result.source;
        NodeID target = all_edges_list[i].result.target;

        int min_forward_weight = std::numeric_limits<int>::max();
        int min_backward_weight = std::numeric_limits<int>::max();
        unsigned min_forward_idx = std::numeric_limits<unsigned>::max();
        unsigned min_backward_idx = std::numeric_limits<unsigned>::max();

        // find minimal edge in both directions
        while (all_edges_list[i].result.source == source &&
               all_edges_list[i].result.target == target)
        {
            if (all_edges_list[i].result.forward &&
                all_edges_list[i].result.weight < min_forward_weight)
            {
                min_forward_idx = i;
                min_forward_weight = all_edges_list[i].result.weight;
            }
            if (all_edges_list[i].result.backward &&
                all_edges_list[i].result.weight < min_backward_weight)
            {
                min_backward_idx = i;
                min_backward_weight = all_edges_list[i].result.weight;
            }

            // this also increments the outer loop counter!
            i++;
        }

        BOOST_ASSERT(min_forward_idx == std::numeric_limits<unsigned>::max() ||
                     min_forward_idx < i);
        BOOST_ASSERT(min_backward_idx == std::numeric_limits<unsigned>::max() ||
                     min_backward_idx < i);
        BOOST_ASSERT(min_backward_idx != std::numeric_limits<unsigned>::max() ||
                     min_forward_idx != std::numeric_limits<unsigned>::max());

        if (min_backward_idx == min_forward_idx)
        {
            all_edges_list[min_forward_idx].result.is_split = false;
            all_edges_list[min_forward_idx].result.forward = true;
            all_edges_list[min_forward_idx].result.backward = true;
        }
        else
        {
            bool has_forward = min_forward_idx != std::numeric_limits<unsigned>::max();
            bool has_backward = min_backward_idx != std::numeric_limits<unsigned>::max();
            if (has_forward)
            {
                all_edges_list[min_forward_idx].result.forward = true;
                all_edges_list[min_forward_idx].result.backward = false;
                all_edges_list[min_forward_idx].result.is_split = has_backward;
            }
            if (has_backward)
            {
                std::swap(all_edges_list[min_backward_idx].result.source,
                          all_edges_list[min_backward_idx].result.target);
                all_edges_list[min_backward_idx].result.forward = true;
                all_edges_list[min_backward_idx].result.backward = false;
                all_edges_list[min_backward_idx].result.is_split = has_forward;
            }
        }

        // invalidate all unused edges
        for (unsigned j = start_idx; j < i; j++)
        {
            if (j == min_forward_idx || j == min_backward_idx)
            {
                continue;
            }
            all_edges_list[j].result.source = SPECIAL_NODEID;
            all_edges_list[j].result.target = SPECIAL_NODEID;
        }
    }
}

void ExtractionContainers::WriteEdges(std::ofstream &file_out_stream) const
{
    std::cout << "[extractor] Writing used edges       ... " << std::flush;
    TIMER_START(write_edges);
    // Traverse list of edges and nodes in parallel and set target coord
    std::uint64_t used_edges_counter = 0;
    std::uint32_t used_edges_counter_buffer = 0;

    auto start_position = file_out_stream.tellp();
    file_out_stream.write((char *)&used_edges_counter_buffer, sizeof(used_edges_counter_buffer));

    for (const auto &edge : all_edges_list)
    {
        if (edge.result.source == SPECIAL_NODEID || edge.result.target == SPECIAL_NODEID)
        {
            continue;
        }

        // IMPORTANT: here, we're using slicing to only write the data from the base
        // class of NodeBasedEdgeWithOSM
        NodeBasedEdge tmp = edge.result;
        file_out_stream.write((char *)&tmp, sizeof(NodeBasedEdge));
        used_edges_counter++;
    }

    if (used_edges_counter > std::numeric_limits<unsigned>::max())
    {
        throw util::exception("There are too many edges, OSRM only supports 2^32");
    }
    TIMER_STOP(write_edges);
    std::cout << "ok, after " << TIMER_SEC(write_edges) << "s" << std::endl;

    std::cout << "[extractor] setting number of edges   ... " << std::flush;

    used_edges_counter_buffer = boost::numeric_cast<std::uint32_t>(used_edges_counter);

    file_out_stream.seekp(start_position);
    file_out_stream.write((char *)&used_edges_counter_buffer, sizeof(used_edges_counter_buffer));
    std::cout << "ok" << std::endl;

    util::SimpleLogger().Write() << "Processed " << used_edges_counter << " edges";
}

void ExtractionContainers::WriteNodes(std::ofstream &file_out_stream) const
{
    // write dummy value, will be overwritten later
    std::cout << "[extractor] setting number of nodes   ... " << std::flush;
    file_out_stream.write((char *)&max_internal_node_id, sizeof(unsigned));
    std::cout << "ok" << std::endl;

    std::cout << "[extractor] Confirming/Writing used nodes     ... " << std::flush;
    TIMER_START(write_nodes);
    // identify all used nodes by a merging step of two sorted lists
    auto node_iterator = all_nodes_list.begin();
    auto node_id_iterator = used_node_id_list.begin();
    const auto used_node_id_list_end = used_node_id_list.end();
    const auto all_nodes_list_end = all_nodes_list.end();

    while (node_id_iterator != used_node_id_list_end && node_iterator != all_nodes_list_end)
    {
        if (*node_id_iterator < node_iterator->node_id)
        {
            ++node_id_iterator;
            continue;
        }
        if (*node_id_iterator > node_iterator->node_id)
        {
            ++node_iterator;
            continue;
        }
        BOOST_ASSERT(*node_id_iterator == node_iterator->node_id);

        file_out_stream.write((char *)&(*node_iterator), sizeof(ExternalMemoryNode));

        ++node_id_iterator;
        ++node_iterator;
    }
    TIMER_STOP(write_nodes);
    std::cout << "ok, after " << TIMER_SEC(write_nodes) << "s" << std::endl;

    util::SimpleLogger().Write() << "Processed " << max_internal_node_id << " nodes";
}

void ExtractionContainers::WriteRestrictions(const std::string &path) const
{
    // serialize restrictions
    std::ofstream restrictions_out_stream;
    unsigned written_restriction_count = 0;
    restrictions_out_stream.open(path.c_str(), std::ios::binary);
    const util::FingerPrint fingerprint = util::FingerPrint::GetValid();
    restrictions_out_stream.write((char *)&fingerprint, sizeof(util::FingerPrint));
    const auto count_position = restrictions_out_stream.tellp();
    restrictions_out_stream.write((char *)&written_restriction_count, sizeof(unsigned));

    for (const auto &restriction_container : restrictions_list)
    {
        if (SPECIAL_NODEID != restriction_container.restriction.from.node &&
            SPECIAL_NODEID != restriction_container.restriction.via.node &&
            SPECIAL_NODEID != restriction_container.restriction.to.node)
        {
            restrictions_out_stream.write((char *)&(restriction_container.restriction),
                                          sizeof(TurnRestriction));
            ++written_restriction_count;
        }
    }
    restrictions_out_stream.seekp(count_position);
    restrictions_out_stream.write((char *)&written_restriction_count, sizeof(unsigned));
    util::SimpleLogger().Write() << "usable restrictions: " << written_restriction_count;
}

void ExtractionContainers::PrepareRestrictions()
{
    std::cout << "[extractor] Sorting used ways         ... " << std::flush;
    TIMER_START(sort_ways);
    stxxl::sort(way_start_end_id_list.begin(),
                way_start_end_id_list.end(),
                FirstAndLastSegmentOfWayStxxlCompare(),
                stxxl_memory);
    TIMER_STOP(sort_ways);
    std::cout << "ok, after " << TIMER_SEC(sort_ways) << "s" << std::endl;

    std::cout << "[extractor] Sorting " << restrictions_list.size() << " restriction. by from... "
              << std::flush;
    TIMER_START(sort_restrictions);
    stxxl::sort(restrictions_list.begin(),
                restrictions_list.end(),
                CmpRestrictionContainerByFrom(),
                stxxl_memory);
    TIMER_STOP(sort_restrictions);
    std::cout << "ok, after " << TIMER_SEC(sort_restrictions) << "s" << std::endl;

    std::cout << "[extractor] Fixing restriction starts ... " << std::flush;
    TIMER_START(fix_restriction_starts);
    auto restrictions_iterator = restrictions_list.begin();
    auto way_start_and_end_iterator = way_start_end_id_list.cbegin();
    const auto restrictions_list_end = restrictions_list.end();
    const auto way_start_end_id_list_end = way_start_end_id_list.cend();

    while (way_start_and_end_iterator != way_start_end_id_list_end &&
           restrictions_iterator != restrictions_list_end)
    {
        if (way_start_and_end_iterator->way_id <
            OSMWayID{static_cast<std::uint32_t>(restrictions_iterator->restriction.from.way)})
        {
            ++way_start_and_end_iterator;
            continue;
        }

        if (way_start_and_end_iterator->way_id >
            OSMWayID{static_cast<std::uint32_t>(restrictions_iterator->restriction.from.way)})
        {
            util::SimpleLogger().Write(LogLevel::logWARNING)
                << "Restriction references invalid way: "
                << restrictions_iterator->restriction.from.way;
            restrictions_iterator->restriction.from.node = SPECIAL_NODEID;
            ++restrictions_iterator;
            continue;
        }

        BOOST_ASSERT(way_start_and_end_iterator->way_id ==
                     OSMWayID{static_cast<std::uint32_t>(restrictions_iterator->restriction.from.way)});
        // we do not remap the via id yet, since we will need it for the to node as well
        const OSMNodeID via_node_id = OSMNodeID{restrictions_iterator->restriction.via.node};

        // check if via is actually valid, if not invalidate
        auto via_id_iter = external_to_internal_node_id_map.find(via_node_id);
        if (via_id_iter == external_to_internal_node_id_map.end())
        {
            util::SimpleLogger().Write(LogLevel::logWARNING)
                << "Restriction references invalid node: "
                << restrictions_iterator->restriction.via.node;
            restrictions_iterator->restriction.via.node = SPECIAL_NODEID;
            ++restrictions_iterator;
            continue;
        }

        if (way_start_and_end_iterator->first_segment_source_id == via_node_id)
        {
            // assign new from node id
            auto id_iter = external_to_internal_node_id_map.find(
                way_start_and_end_iterator->first_segment_target_id);
            if (id_iter == external_to_internal_node_id_map.end())
            {
                util::SimpleLogger().Write(LogLevel::logWARNING)
                    << "Way references invalid node: "
                    << way_start_and_end_iterator->first_segment_target_id;
                restrictions_iterator->restriction.from.node = SPECIAL_NODEID;
                ++restrictions_iterator;
                ++way_start_and_end_iterator;
                continue;
            }
            restrictions_iterator->restriction.from.node = id_iter->second;
        }
        else if (way_start_and_end_iterator->last_segment_target_id == via_node_id)
        {
            // assign new from node id
            auto id_iter = external_to_internal_node_id_map.find(
                way_start_and_end_iterator->last_segment_source_id);
            if (id_iter == external_to_internal_node_id_map.end())
            {
                util::SimpleLogger().Write(LogLevel::logWARNING)
                    << "Way references invalid node: "
                    << way_start_and_end_iterator->last_segment_target_id;
                restrictions_iterator->restriction.from.node = SPECIAL_NODEID;
                ++restrictions_iterator;
                ++way_start_and_end_iterator;
                continue;
            }
            restrictions_iterator->restriction.from.node = id_iter->second;
        }
        ++restrictions_iterator;
    }

    TIMER_STOP(fix_restriction_starts);
    std::cout << "ok, after " << TIMER_SEC(fix_restriction_starts) << "s" << std::endl;

    std::cout << "[extractor] Sorting restrictions. by to  ... " << std::flush;
    TIMER_START(sort_restrictions_to);
    stxxl::sort(restrictions_list.begin(),
                restrictions_list.end(),
                CmpRestrictionContainerByTo(),
                stxxl_memory);
    TIMER_STOP(sort_restrictions_to);
    std::cout << "ok, after " << TIMER_SEC(sort_restrictions_to) << "s" << std::endl;

    std::cout << "[extractor] Fixing restriction ends   ... " << std::flush;
    TIMER_START(fix_restriction_ends);
    restrictions_iterator = restrictions_list.begin();
    way_start_and_end_iterator = way_start_end_id_list.cbegin();
    const auto way_start_end_id_list_end_ = way_start_end_id_list.cend();
    const auto restrictions_list_end_ = restrictions_list.end();

    while (way_start_and_end_iterator != way_start_end_id_list_end_ &&
           restrictions_iterator != restrictions_list_end_)
    {
        if (way_start_and_end_iterator->way_id <
            OSMWayID{static_cast<std::uint32_t>(restrictions_iterator->restriction.to.way)})
        {
            ++way_start_and_end_iterator;
            continue;
        }
        if (restrictions_iterator->restriction.from.node == SPECIAL_NODEID ||
            restrictions_iterator->restriction.via.node == SPECIAL_NODEID)
        {
            ++restrictions_iterator;
            continue;
        }
        if (way_start_and_end_iterator->way_id >
            OSMWayID{static_cast<std::uint32_t>(restrictions_iterator->restriction.to.way)})
        {
            util::SimpleLogger().Write(LogLevel::logDEBUG)
                << "Restriction references invalid way: "
                << restrictions_iterator->restriction.to.way;
            restrictions_iterator->restriction.to.way = SPECIAL_NODEID;
            ++restrictions_iterator;
            continue;
        }
        BOOST_ASSERT(way_start_and_end_iterator->way_id ==
                     OSMWayID{static_cast<std::uint32_t>(restrictions_iterator->restriction.to.way)});
        const OSMNodeID via_node_id = OSMNodeID{restrictions_iterator->restriction.via.node};

        // assign new via node id
        auto via_id_iter = external_to_internal_node_id_map.find(via_node_id);
        BOOST_ASSERT(via_id_iter != external_to_internal_node_id_map.end());
        restrictions_iterator->restriction.via.node = via_id_iter->second;

        if (way_start_and_end_iterator->first_segment_source_id == via_node_id)
        {
            auto to_id_iter = external_to_internal_node_id_map.find(
                way_start_and_end_iterator->first_segment_target_id);
            if (to_id_iter == external_to_internal_node_id_map.end())
            {
                util::SimpleLogger().Write(LogLevel::logWARNING)
                    << "Way references invalid node: "
                    << way_start_and_end_iterator->first_segment_source_id;
                restrictions_iterator->restriction.to.node = SPECIAL_NODEID;
                ++restrictions_iterator;
                ++way_start_and_end_iterator;
                continue;
            }
            restrictions_iterator->restriction.to.node = to_id_iter->second;
        }
        else if (way_start_and_end_iterator->last_segment_target_id == via_node_id)
        {
            auto to_id_iter = external_to_internal_node_id_map.find(
                way_start_and_end_iterator->last_segment_source_id);
            if (to_id_iter == external_to_internal_node_id_map.end())
            {
                util::SimpleLogger().Write(LogLevel::logWARNING)
                    << "Way references invalid node: "
                    << way_start_and_end_iterator->last_segment_source_id;
                restrictions_iterator->restriction.to.node = SPECIAL_NODEID;
                ++restrictions_iterator;
                ++way_start_and_end_iterator;
                continue;
            }
            restrictions_iterator->restriction.to.node = to_id_iter->second;
        }
        ++restrictions_iterator;
    }
    TIMER_STOP(fix_restriction_ends);
    std::cout << "ok, after " << TIMER_SEC(fix_restriction_ends) << "s" << std::endl;
}
}
}