/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#ifndef OCEANBASE_SQL_ENGINE_EXPR_ROWNUM_H_
#define OCEANBASE_SQL_ENGINE_EXPR_ROWNUM_H_

#include "sql/engine/expr/ob_expr_operator.h"
#include "sql/engine/expr/ob_expr.h"

namespace oceanbase {
namespace sql {
class ObExprCGCtx;
class ObExprRowNum : public ObFuncExprOperator {
  OB_UNIS_VERSION(1);

public:
  explicit ObExprRowNum(common::ObIAllocator& alloc);
  virtual ~ObExprRowNum();
  virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const;
  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const;

  // CG && evaluating function for static typing engine
  virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
  static int rownum_eval(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
  void set_op_id(uint64_t operator_id)
  {
    operator_id_ = operator_id;
  }

private:
  uint64_t operator_id_;
  DISALLOW_COPY_AND_ASSIGN(ObExprRowNum);
};

} /* namespace sql */
} /* namespace oceanbase */

#endif /* OCEANBASE_SQL_ENGINE_EXPR_ROWNUM_H_ */
