Method GetTopLocalities

libs/search/locality_scorer.cpp:92–164

{}

void LocalityScorer::GetTopLocalities(MwmSet::MwmId const & countryId, BaseContext const & ctx, CBV const & filter,
                                      size_t limit, vector<Locality> & localities)
{
  double constexpr kUnknownIdf = 1.0;
  size_t const numTokens = ctx.NumTokens();
  ASSERT_EQUAL(numTokens, m_params.GetNumTokens(), ());

  localities.clear();

  vector<Retrieval::ExtendedFeatures> intersections(numTokens);
  vector<pair<LevenshteinDFA, uint64_t>> tokensToDf;
  vector<pair<PrefixDFA, uint64_t>> prefixToDf;
  bool const havePrefix = numTokens > 0 && m_params.LastTokenIsPrefix();
  size_t const nonPrefixTokens = havePrefix ? numTokens - 1 : numTokens;
  for (size_t i = 0; i < nonPrefixTokens; ++i)
  {
    intersections[i] = ctx.m_features[i].Intersect(filter);
    auto const df = intersections[i].m_features.PopCount();
    if (df != 0)
    {
      auto const & token = m_params.GetToken(i);
      tokensToDf.emplace_back(BuildLevenshteinDFA(token.GetOriginal()), df);
      token.ForEachSynonym([&tokensToDf, &df](UniString const & s)
      { tokensToDf.emplace_back(strings::LevenshteinDFA(s, 0 /* maxErrors */), df); });
    }
  }

  if (havePrefix)
  {
    auto const count = numTokens - 1;
    intersections[count] = ctx.m_features[count].Intersect(filter);
    auto const prefixDf = intersections[count].m_features.PopCount();
    if (prefixDf != 0)
    {
      auto const & token = m_params.GetToken(count);
      prefixToDf.emplace_back(PrefixDFA(BuildLevenshteinDFA(token.GetOriginal())), prefixDf);
      token.ForEachSynonym([&prefixToDf, &prefixDf](UniString const & s)
      { prefixToDf.emplace_back(PrefixDFA(strings::LevenshteinDFA(s, 0 /* maxErrors */)), prefixDf); });
    }
  }

  IdfMapDelegate delegate(tokensToDf, prefixToDf);
  IdfMap idfs(delegate, kUnknownIdf);

  for (size_t startToken = 0; startToken < numTokens; ++startToken)
  {
    auto intersection = intersections[startToken];
    QueryVec::Builder builder;

    for (size_t endToken = startToken + 1; endToken <= numTokens && !intersection.m_features.IsEmpty(); ++endToken)
    {
      auto const curToken = endToken - 1;
      auto const & token = m_params.GetToken(curToken).GetOriginal();
      if (m_params.IsPrefixToken(curToken))
        builder.SetPrefix(token);
      else
        builder.AddFull(token);