Method Serialize

libs/routing/maxspeeds_serialization.hpp:80–163

  template <class Sink>
  static void Serialize(std::vector<FeatureSpeedMacro> const & featureSpeeds, HW2SpeedMap typeSpeeds[], Sink & sink)
  {
    CHECK(base::IsSortedAndUnique(featureSpeeds.cbegin(), featureSpeeds.cend(),
                                  [](FeatureSpeedMacro const & l, FeatureSpeedMacro const & r)
    { return l.m_featureID < r.m_featureID; }),
          ());

    // Version
    auto const startOffset = sink.Pos();
    WriteToSink(sink, kVersion);

    // Header
    auto const headerOffset = sink.Pos();
    Header header;
    header.Serialize(sink);

    auto const forwardMaxspeedTableOffset = sink.Pos();

    // Saving forward (one direction) maxspeeds.
    uint32_t maxFeatureID;
    std::vector<uint8_t> forwardMaxspeeds = GetForwardMaxspeeds(featureSpeeds, maxFeatureID);

    size_t forwardCount = forwardMaxspeeds.size();
    if (forwardCount > 0)
    {
      succinct::elias_fano::elias_fano_builder builder(maxFeatureID + 1, forwardCount);
      for (auto const & e : featureSpeeds)
        if (!e.IsBidirectional())
          builder.push_back(e.m_featureID);

      coding::FreezeVisitor<Writer> visitor(sink);
      succinct::elias_fano(&builder).map(visitor);

      header.m_forwardMaxspeedOffset = static_cast<uint32_t>(sink.Pos() - forwardMaxspeedTableOffset);

      coding::SimpleDenseCoding simpleDenseCoding(forwardMaxspeeds);
      coding::Freeze(simpleDenseCoding, sink, "ForwardMaxspeeds");
    }
    else
    {
      header.m_forwardMaxspeedOffset = 0;
    }
    header.m_bidirectionalMaxspeedOffset = static_cast<uint32_t>(sink.Pos() - forwardMaxspeedTableOffset);

    // Saving bidirectional maxspeeds.
    uint32_t prevFeatureId = 0;
    for (auto const & s : featureSpeeds)
    {
      if (!s.IsBidirectional())
        continue;

      ++header.m_bidirectionalMaxspeedNumber;

      // Valid, because we did base::IsSortedAndUnique in the beginning.
      WriteVarUint(sink, s.m_featureID - prevFeatureId);
      prevFeatureId = s.m_featureID;

      WriteToSink(sink, static_cast<uint8_t>(s.m_forward));