70 lines
2.2 KiB
C++
70 lines
2.2 KiB
C++
/**
|
|
* 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_RANDOM_H_
|
|
#define OCEANBASE_SQL_OB_EXPR_FUNC_RANDOM_H_
|
|
|
|
#include "sql/engine/expr/ob_expr_operator.h"
|
|
|
|
namespace oceanbase
|
|
{
|
|
namespace sql
|
|
{
|
|
class ObExprRandom: public ObFuncExprOperator
|
|
{
|
|
OB_UNIS_VERSION(1);
|
|
class ObExprRandomCtx: public ObExprOperatorCtx
|
|
{
|
|
public:
|
|
ObExprRandomCtx();
|
|
virtual ~ObExprRandomCtx();
|
|
void set_seed(uint32_t seed);
|
|
void get_next_random(double &res);
|
|
private:
|
|
static const uint64_t max_value_;
|
|
uint64_t seed1_;
|
|
uint64_t seed2_;
|
|
};
|
|
public:
|
|
explicit ObExprRandom(common::ObIAllocator &alloc);
|
|
virtual ~ObExprRandom();
|
|
virtual int calc_result_typeN(ObExprResType &type,
|
|
ObExprResType *types,
|
|
int64_t param_num,
|
|
common::ObExprTypeCtx &type_ctx) const;
|
|
inline void set_seed_const(bool is_seed_const);
|
|
|
|
// engine 3.0
|
|
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 calc_random_expr_const_seed(const ObExpr &expr, ObEvalCtx &ctx,
|
|
ObDatum &res_datum);
|
|
static int calc_random_expr_nonconst_seed(const ObExpr &expr, ObEvalCtx &ctx,
|
|
ObDatum &res_datum);
|
|
public:
|
|
virtual int assign(const ObExprOperator &other) override;
|
|
private:
|
|
bool is_seed_const_;
|
|
// disallow copy
|
|
DISALLOW_COPY_AND_ASSIGN(ObExprRandom);
|
|
};
|
|
|
|
inline void ObExprRandom::set_seed_const(bool is_seed_const)
|
|
{
|
|
is_seed_const_ = is_seed_const;
|
|
}
|
|
} /* namespace sql */
|
|
} /* namespace oceanbase */
|
|
|
|
#endif /* OCEANBASE_SQL_OB_EXPR_FUNC_RANDOM_H_ */
|