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#include "search/streets_matcher.hpp"
#include "search/features_filter.hpp"
#include "search/house_numbers_matcher.hpp"
#include "search/query_params.hpp"
#include "indexer/search_string_utils.hpp"
#include "base/logging.hpp"
#include "base/stl_helpers.hpp"
using namespace std;
namespace search
{
namespace
{
bool LessByHash(StreetsMatcher::Prediction const & lhs, StreetsMatcher::Prediction const & rhs)
{
if (lhs.m_hash != rhs.m_hash)
return lhs.m_hash < rhs.m_hash;
if (lhs.m_prob != rhs.m_prob)
return lhs.m_prob > rhs.m_prob;
if (lhs.GetNumTokens() != rhs.GetNumTokens())
return lhs.GetNumTokens() > rhs.GetNumTokens();
return lhs.m_tokenRange.Begin() < rhs.m_tokenRange.Begin();
}
} // namespace
// static
void StreetsMatcher::Go(BaseContext const & ctx, FeaturesFilter const & filter,
QueryParams const & params, vector<Prediction> & predictions)
{
size_t const kMaxNumOfImprobablePredictions = 3;
double const kTailProbability = 0.05;
predictions.clear();
FindStreets(ctx, filter, params, predictions);
if (predictions.empty())
return;
sort(predictions.begin(), predictions.end(), &LessByHash);
predictions.erase(
unique(predictions.begin(), predictions.end(), base::EqualsBy(&Prediction::m_hash)),
predictions.end());
sort(predictions.rbegin(), predictions.rend(), base::LessBy(&Prediction::m_prob));
while (predictions.size() > kMaxNumOfImprobablePredictions &&
predictions.back().m_prob < kTailProbability)
{
predictions.pop_back();
}
}
// static
void StreetsMatcher::FindStreets(BaseContext const & ctx, FeaturesFilter const & filter,
QueryParams const & params, vector<Prediction> & predictions)
{
for (size_t startToken = 0; startToken < ctx.m_numTokens; ++startToken)
{
if (ctx.IsTokenUsed(startToken))
continue;
// Here we try to match as many tokens as possible while
// intersection is a non-empty bit vector of streets. Single
// tokens that are synonyms to streets are ignored. Moreover,
// each time a token that looks like a beginning of a house number
// is met, we try to use current intersection of tokens as a
// street layer and try to match BUILDINGs or POIs.
CBV streets(ctx.m_streets);
CBV all;
all.SetFull();
size_t curToken = startToken;
// This variable is used for prevention of duplicate calls to
// CreateStreetsLayerAndMatchLowerLayers() with the same
// arguments.
size_t lastToken = startToken;
// When true, no bit vectors were intersected with |streets| at all.
bool emptyIntersection = true;
// When true, |streets| is in the incomplete state and can't be
// used for creation of street layers.
bool incomplete = false;
auto emit = [&]()
{
if (!streets.IsEmpty() && !emptyIntersection && !incomplete && lastToken != curToken)
{
CBV fs(streets);
CBV fa(all);
ASSERT(!fs.IsFull(), ());
ASSERT(!fa.IsFull(), ());
if (filter.NeedToFilter(fs))
fs = filter.Filter(fs);
if (fs.IsEmpty())
return;
if (filter.NeedToFilter(fa))
fa = filter.Filter(fa).Union(fs);
predictions.emplace_back();
auto & prediction = predictions.back();
prediction.m_tokenRange = TokenRange(startToken, curToken);
ASSERT_NOT_EQUAL(fs.PopCount(), 0, ());
ASSERT_LESS_OR_EQUAL(fs.PopCount(), fa.PopCount(), ());
prediction.m_prob = static_cast<double>(fs.PopCount()) / static_cast<double>(fa.PopCount());
prediction.m_features = move(fs);
prediction.m_hash = prediction.m_features.Hash();
}
};
StreetTokensFilter filter([&](strings::UniString const & /* token */, size_t tag)
{
auto buffer = streets.Intersect(ctx.m_features[tag]);
if (tag < curToken)
{
// This is the case for delayed
// street synonym. Therefore,
// |streets| is temporarily in the
// incomplete state.
streets = buffer;
all = all.Intersect(ctx.m_features[tag]);
emptyIntersection = false;
incomplete = true;
return;
}
ASSERT_EQUAL(tag, curToken, ());
// |streets| will become empty after
// the intersection. Therefore we need
// to create streets layer right now.
if (buffer.IsEmpty())
emit();
streets = buffer;
all = all.Intersect(ctx.m_features[tag]);
emptyIntersection = false;
incomplete = false;
});
for (; curToken < ctx.m_numTokens && !ctx.IsTokenUsed(curToken) && !streets.IsEmpty();
++curToken)
{
auto const & token = params.GetToken(curToken).GetOriginal();
bool const isPrefix = params.IsPrefixToken(curToken);
if (house_numbers::LooksLikeHouseNumber(token, isPrefix))
emit();
filter.Put(token, isPrefix, curToken);
}
emit();
}
}
} // namespace search
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