Method PrepareContext

catboost/cuda/cuda_util/sort.cpp:134–156

        }

        THolder<TKernelContext> PrepareContext(IMemoryManager& manager) const {
            CB_ENSURE(Keys.Size() == Keys.ObjectCount(), LabeledOutput(Keys.Size(), Keys.ObjectCount()));
            CB_ENSURE(Keys.Size() < (static_cast<ui64>(1) << 32), LabeledOutput(Keys.Size()));

            const ui32 size = Keys.Size();
            const ui32 valueSize = Values.Size() ? sizeof(V) : 0;
            if (valueSize) {
                CB_ENSURE(Values.Size() == Keys.Size());
            }
            auto context = MakeHolder<TKernelContext>(FirstBit, LastBit, valueSize, CompareGreater);
            context->UseExternalBufferForTempKeysAndValues = TmpKeys.Size() > 0;

            if (size) {
                //fill temp storage size by cub
                CUDA_SAFE_CALL(NKernel::RadixSort((K*)nullptr, (TValueStorage*)nullptr, size, *context, 0));
                if (context->UseExternalBufferForTempKeysAndValues) {
                    AllocateMemory<true>(manager, size, *context);
                } else {
                    AllocateMemory<false>(manager, size, *context);
                }
            }
            return context;
        }

        void Run(const TCudaStream& stream, TKernelContext& context) const {
            const ui32 size = SafeIntegerCast<ui32>(Keys.Size());