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oceanbase/src/sql/engine/expr/ob_expr_generator_func.h

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/**
* 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_OB_EXPR_FUNC_GENERATOR_FUNC_H_
#define OCEANBASE_SQL_OB_EXPR_FUNC_GENERATOR_FUNC_H_
#include "sql/engine/expr/ob_expr_operator.h"
namespace oceanbase
{
namespace sql
{
class ObExprGeneratorFunc : public ObFuncExprOperator
{
class ObExprGeneratorFuncCtx: public ObExprOperatorCtx
{
public:
ObExprGeneratorFuncCtx() : curr_value_(0) {}
~ObExprGeneratorFuncCtx() = default;
// increment 1 after every call to expr evaluation
int64_t curr_value_;
};
public:
explicit ObExprGeneratorFunc(common::ObIAllocator &alloc);
virtual ~ObExprGeneratorFunc();
virtual int calc_result_type1(ObExprResType &type,
ObExprResType &limit,
common::ObExprTypeCtx &type_ctx) const;
virtual bool need_rt_ctx() const override { return true; }
virtual int cg_expr(ObExprCGCtx &expr_cg_ctx,
const ObRawExpr &raw_expr,
ObExpr &rt_expr) const override;
static int eval_next_value(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &res_datum);
private:
DISALLOW_COPY_AND_ASSIGN(ObExprGeneratorFunc);
};
} /* namespace sql */
} /* namespace oceanbase */
#endif /* OCEANBASE_SQL_OB_EXPR_FUNC_GENERATOR_FUNC_H_ */