Method Init

be/src/exec/union-node.cc:36–69

using namespace impala;

Status UnionPlanNode::Init(const TPlanNode& tnode, FragmentState* state) {
  RETURN_IF_ERROR(PlanNode::Init(tnode, state));
  DCHECK(tnode_->__isset.union_node);
  DCHECK_EQ(conjuncts_.size(), 0);
  tuple_desc_ = state->desc_tbl().GetTupleDescriptor(tnode_->union_node.tuple_id);
  DCHECK(tuple_desc_ != nullptr);
  first_materialized_child_idx_ = tnode_->union_node.first_materialized_child_idx;
  DCHECK_GT(first_materialized_child_idx_, -1);
  const int64_t num_nonconst_scalar_expr_to_be_codegened =
      state->NumScalarExprNeedsCodegen();
  // Create const_exprs_lists_ from thrift exprs.
  const vector<vector<TExpr>>& const_texpr_lists = tnode_->union_node.const_expr_lists;
  for (const vector<TExpr>& texprs : const_texpr_lists) {
    vector<ScalarExpr*> const_exprs;
    RETURN_IF_ERROR(ScalarExpr::Create(texprs, *row_descriptor_, state, &const_exprs));
    DCHECK_EQ(const_exprs.size(), tuple_desc_->slots().size());
    const_exprs_lists_.push_back(const_exprs);
  }
  num_const_scalar_expr_to_be_codegened_ =
      state->NumScalarExprNeedsCodegen() - num_nonconst_scalar_expr_to_be_codegened;
  // Create child_exprs_lists_ from thrift exprs.
  const vector<vector<TExpr>>& thrift_result_exprs = tnode_->union_node.result_expr_lists;
  for (int i = 0; i < thrift_result_exprs.size(); ++i) {
    const vector<TExpr>& texprs = thrift_result_exprs[i];
    vector<ScalarExpr*> child_exprs;
    RETURN_IF_ERROR(
        ScalarExpr::Create(texprs, *children_[i]->row_descriptor_, state, &child_exprs));
    child_exprs_lists_.push_back(child_exprs);
    DCHECK_EQ(child_exprs.size(), tuple_desc_->slots().size());
  }
  codegend_union_materialize_batch_fns_ =
      std::vector<CodegenFnPtr<UnionMaterializeBatchFn>>(child_exprs_lists_.size());
  return Status::OK();
}

void UnionPlanNode::Close() {
  for (const vector<ScalarExpr*>& const_exprs : const_exprs_lists_) {