Method LeaveTopLocalities

libs/search/locality_scorer.cpp:166–223

}

void LocalityScorer::LeaveTopLocalities(IdfMap & idfs, size_t limit, vector<Locality> & localities)
{
  vector<ExLocality> els;
  els.reserve(localities.size());
  for (auto & locality : localities)
  {
    auto const queryNorm = locality.m_queryVec.Norm();
    auto const rank = m_delegate.GetRank(locality.GetFeatureIndex());
    els.emplace_back(std::move(locality), queryNorm, rank);
  }

  // We don't want to read too many names for localities, so this is
  // the best effort - select the best features by available params -
  // exactMatch, query norm and rank.
  LeaveTopByExactMatchNormAndRank(max(limit, kDefaultReadLimit) /* limitUniqueIds */, els);

  sort(els.begin(), els.end(),
       [](ExLocality const & lhs, ExLocality const & rhs) { return lhs.GetId() < rhs.GetId(); });

  size_t i = 0;
  while (i < els.size())
  {
    size_t j = i + 1;
    while (j < els.size() && els[j].GetId() == els[i].GetId())
      ++j;

    vector<DocVec> dvs;

    // *NOTE* |idfs| is filled based on query tokens, not all
    // localities tokens, because it's expensive to compute IDF map
    // for all localities tokens.  Therefore, for tokens not in the
    // query, some default IDF value will be used.
    GetDocVecs(els[i].GetId(), dvs);

    auto const center = m_delegate.GetCenter(els[i].GetId());
    auto const distance = center ? mercator::DistanceOnEarth(m_pivot, *center) : els[i].m_distanceToPivot;
    auto const belongsToMatchedRegion =
        center ? m_delegate.BelongsToMatchedRegion(*center) : els[i].m_belongsToMatchedRegion;

    for (; i < j; ++i)
    {
      els[i].m_similarity = GetSimilarity(els[i].m_locality.m_queryVec, idfs, dvs);
      els[i].m_distanceToPivot = distance;
      els[i].m_belongsToMatchedRegion = belongsToMatchedRegion;
    }
  }

  GroupBySimilarityAndOther(els);

  localities.clear();
  localities.reserve(els.size());

  ankerl::unordered_dense::set<uint32_t> seen;
  for (auto it = els.begin(); it != els.end() && localities.size() < limit; ++it)
    if (seen.insert(it->GetId()).second)
      localities.push_back(std::move(it->m_locality));
  ASSERT_EQUAL(seen.size(), localities.size(), ());
}