Method ColumnsView

catboost/cuda/cuda_lib/cuda_buffer.h:168–185

        }

        TCudaBuffer<const T, TMapping, Type> ColumnsView(const TSlice& columns) const {
            CB_ENSURE(columns.Right <= ColumnCount);
            TCudaBuffer<const T, TMapping, Type> buffer;
            auto slice = GetObjectsSlice();
            buffer.Mapping = Mapping.ToLocalSlice(slice);
            buffer.ColumnCount = columns.Size();

            for (ui64 i = 0; i < Buffers.size(); ++i) {
                if (Buffers[i].NotEmpty()) {
                    const ui64 columnsShift = NAligment::ColumnShift(Mapping.MemoryUsageAt(i), columns.Left);
                    const auto devSlice = TSlice::Intersection(slice, Mapping.DeviceSlice(i));
                    buffer.Buffers[i] = Buffers[i].ShiftedConstBuffer(
                        columnsShift + Mapping.DeviceMemoryOffset(i, devSlice));
                }
            }
            buffer.IsSliceView = true;
            return buffer;
        }

        TCudaBuffer<T, TMapping, Type> ColumnsView(const TSlice& columns) {
            CB_ENSURE(columns.Right <= ColumnCount);