70 lines
2.2 KiB
C++
70 lines
2.2 KiB
C++
/**
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* Copyright (c) 2021 OceanBase
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* OceanBase CE is licensed under Mulan PubL v2.
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* You can use this software according to the terms and conditions of the Mulan PubL v2.
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* You may obtain a copy of Mulan PubL v2 at:
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* http://license.coscl.org.cn/MulanPubL-2.0
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* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
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* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
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* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
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* See the Mulan PubL v2 for more details.
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*/
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#ifndef OCEANBASE_SQL_OB_EXPR_FUNC_RAND_H_
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#define OCEANBASE_SQL_OB_EXPR_FUNC_RAND_H_
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#include "sql/engine/expr/ob_expr_operator.h"
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namespace oceanbase
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{
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namespace sql
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{
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class ObExprRand: public ObFuncExprOperator
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{
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OB_UNIS_VERSION(1);
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class ObExprRandCtx: public ObExprOperatorCtx
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{
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public:
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ObExprRandCtx();
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virtual ~ObExprRandCtx();
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void set_seed(uint32_t seed);
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void get_next_random(double &res);
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private:
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static const uint64_t max_value_;
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uint64_t seed1_;
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uint64_t seed2_;
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};
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public:
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explicit ObExprRand(common::ObIAllocator &alloc);
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virtual ~ObExprRand();
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virtual int calc_result_typeN(ObExprResType &type,
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ObExprResType *types,
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int64_t param_num,
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common::ObExprTypeCtx &type_ctx) const;
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inline void set_seed_const(bool is_seed_const);
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// engine 3.0
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virtual bool need_rt_ctx() const override { return true; }
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virtual int cg_expr(ObExprCGCtx &expr_cg_ctx, const ObRawExpr &raw_expr,
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ObExpr &rt_expr) const override;
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static int calc_random_expr_const_seed(const ObExpr &expr, ObEvalCtx &ctx,
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ObDatum &res_datum);
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static int calc_random_expr_nonconst_seed(const ObExpr &expr, ObEvalCtx &ctx,
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ObDatum &res_datum);
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public:
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virtual int assign(const ObExprOperator &other) override;
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private:
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bool is_seed_const_;
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// disallow copy
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DISALLOW_COPY_AND_ASSIGN(ObExprRand);
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};
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inline void ObExprRand::set_seed_const(bool is_seed_const)
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{
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is_seed_const_ = is_seed_const;
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}
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} /* namespace sql */
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} /* namespace oceanbase */
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#endif /* OCEANBASE_SQL_OB_EXPR_FUNC_RANDOM_H_ */
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