be/src/exec/empty-set-node.h

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//   http://www.apache.org/licenses/LICENSE-2.0
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#ifndef IMPALA_EXEC_EMPTY_SET_NODE_H_
#define IMPALA_EXEC_EMPTY_SET_NODE_H_

#include "exec/exec-node.h"

namespace impala {

class EmptySetPlanNode : public PlanNode {
 public:
  virtual Status CreateExecNode(RuntimeState* state, ExecNode** node) const override;
  ~EmptySetPlanNode(){}
};

/// Node that returns an empty result set, i.e., just sets eos_ in GetNext().
/// Corresponds to EmptySetNode.java in the FE.

class EmptySetNode : public ExecNode {
 public:
  EmptySetNode(
      ObjectPool* pool, const EmptySetPlanNode& pnode, const DescriptorTbl& descs);
  virtual Status Open(RuntimeState* state) override;
  virtual Status GetNext(RuntimeState* state, RowBatch* row_batch, bool* eos) override;
};

} // namespace impala

#endif