Method AddFeatureTensor

catboost/cuda/gpu_data/oblivious_tree_bin_builder.cpp:123–185

    }
    bool TFeatureTensorTracker::AddFeatureTensor(const TFeatureTensor& featureTensor) {
        const TFeatureTensor prevTensor = CurrentTensor;
        CurrentTensor.AddTensor(featureTensor);
        if (prevTensor == CurrentTensor) {
            return false;
        }

        TCtrBinBuilder<NCudaLib::TMirrorMapping> binBuilder(Stream);

        if (LearnSlice.Size() == 0) {
            binBuilder.SetIndices(LearnDataSet->GetIndices(),
                                  LinkedTest ? &(LinkedTest->GetIndices()) : nullptr);
            LearnSlice = binBuilder.GetLearnSlice();
        } else {
            binBuilder.SetIndices(std::move(Indices),
                                  LearnSlice); //some ping-pong with buffer
        }

        auto catFeatures = NCB::RemoveExisting(CurrentTensor.GetCatFeatures(), prevTensor.GetCatFeatures());
        auto binarySplits = NCB::RemoveExisting(CurrentTensor.GetSplits(), prevTensor.GetSplits());

        TMirrorCatFeatureProvider broadcastedCatFeatures(LearnDataSet->GetCatFeatures(),
                                                         *CacheHolder);

        for (ui32 catFeature : catFeatures) {
            const auto& compressedFeatures = broadcastedCatFeatures.BroadcastFeature(catFeature, Stream)
                                                 .GetInStream(Stream);

            if (LinkedTest) {
                TMirrorCatFeatureProvider broadcastedTestCatFeatures(
                    LinkedTest->GetCatFeatures(),
                    *CacheHolder);
                const auto& compressedTest = broadcastedTestCatFeatures.BroadcastFeature(catFeature, Stream)
                                                 .GetInStream(Stream);
                binBuilder.AddCompressedBins(compressedFeatures,
                                             compressedTest,
                                             FeaturesManager->GetBinCount(catFeature));
            } else {
                binBuilder.AddCompressedBins(compressedFeatures,
                                             FeaturesManager->GetBinCount(catFeature));
            }
        }

        //TODO(noxoomo): builder should merge several task in one
        for (const auto& binarySplit : binarySplits) {
            const auto& learnBits = LearnBinarySplitsProvider->GetCompressedBits(binarySplit);

            if (LinkedTest) {
                const auto& testBits = TestBinarySplitsProvider->GetCompressedBits(binarySplit);

                binBuilder.AddCompressedBins(learnBits,
                                             testBits,
                                             2);
            } else {
                binBuilder.AddCompressedBins(learnBits,
                                             2);
            }
        }