Function AsyncAddArrowNumColumn

catboost/python-package/catboost/arrow.cpp:382–483

    }

    void AsyncAddArrowNumColumn(
        ui32 flatFeatureIdx,
        PyObject* capsule,
        IRawFeaturesOrderDataVisitor* builderVisitor,
        TVector<std::future<void>>* result
    ) {
        auto callback = [=] (TArrowSchemaHolderPtr schema, TArrowArrayHolderPtr array) {
            auto process = [=] () {
                try {
                    CB_ENSURE(array->Data.n_buffers == 2, "Expected two buffers");

                    const ui8* __restrict validity = static_cast<const ui8*>(array->Data.buffers[0]);
                    const void* dataBuf = array->Data.buffers[1];
                    auto arrayOffset = array->Data.offset;
                    auto arraySize = array->Data.length;

                    ITypedSequencePtr<float> result;

                    auto typedProcessing = [&] (const auto* __restrict typedDataBuf) {
                        using TSrcType = std::remove_cvref_t<decltype(*typedDataBuf)>;
                        auto arrayDataHolder = TMaybeOwningConstArrayHolder<TSrcType>::CreateOwning(
                            {typedDataBuf + arrayOffset, typedDataBuf + arrayOffset + arraySize},
                            array
                        );

                        if (validity) {
                            using TInner = TArrayWithValidityHolder<TMaybeOwningConstArrayHolder<TSrcType>>;
                            result = MakeIntrusive<TArrayLikeAsFloatSequence<TInner>>(
                                TInner(
                                    std::move(arrayDataHolder),
                                    TMaybeOwnedBitMap(validity, arrayOffset, arraySize, array)
                                )
                            );
                        } else {
                            result = MakeTypeCastArrayHolder<float>(std::move(arrayDataHolder));
                        }
                    };

                    auto boolProcessing = [&] () {
                        auto data = TMaybeOwnedBitMap(
                            static_cast<const ui8*>(dataBuf),
                            arrayOffset,
                            arraySize,
                            array
                        );
                        if (validity) {
                            using TInner = TArrayWithValidityHolder<TMaybeOwnedBitMap>;
                            result = MakeIntrusive<TArrayLikeAsFloatSequence<TInner>>(
                                TInner(
                                    std::move(data),
                                    TMaybeOwnedBitMap(validity, arrayOffset, arraySize, array)
                                )
                            );
                        } else {
                            result = MakeIntrusive<TArrayLikeAsFloatSequence<TMaybeOwnedBitMap>>(std::move(data));
                        }
                    };