CudfFromVelox supports cudf table

Author: jinchengchenghh

velox/experimental/cudf/exec/CudfConversion.cpp

@@ -86,10 +86,14 @@ void CudfFromVelox::addInput(RowVectorPtr input) {
   VELOX_NVTX_OPERATOR_FUNC_RANGE();
   if (input->size() > 0) {
     // Materialize lazy vectors
-    for (auto& child : input->children()) {
-      child->loadedVector();
+    if (!std::dynamic_pointer_cast<CudfVector>(input)) {
+      for (auto& child : input->children()) {
+        child->loadedVector();
+      }
+      input->loadedVector();
+    } else {
+      isCudfVector_ = true;
     }
-    input->loadedVector();
 
     // Accumulate inputs
     inputs_.push_back(input);
@@ -110,6 +114,13 @@ RowVectorPtr CudfFromVelox::getOutput() {
     return nullptr;
   }
 
+  if (isCudfVector_) {
+    auto first = inputs_.front();
+    inputs_.erase(inputs_.begin());
+    currentOutputSize_ -= first->size();
+    return first;
+  }
+
   // Select inputs that don't exceed the max vector size limit
   std::vector<RowVectorPtr> selectedInputs;
   vector_size_t totalSize = 0;

velox/experimental/cudf/exec/CudfConversion.h

@@ -62,6 +62,7 @@ class CudfFromVelox : public exec::Operator, public NvtxHelper {
   std::vector<RowVectorPtr> inputs_;
   std::size_t currentOutputSize_ = 0;
   bool finished_ = false;
+  bool isCudfVector_ = false;
 };
 
 class CudfToVelox : public exec::Operator, public NvtxHelper {