Files
oceanbase/src/sql/engine/expr/ob_expr_get_sys_var.h
wangzelin.wzl 93a1074b0c patch 4.0
2022-10-24 17:57:12 +08:00

59 lines
2.3 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 _OB_EXPR_GET_SYS_VAR_H
#define _OB_EXPR_GET_SYS_VAR_H 1
#include "sql/engine/expr/ob_expr_operator.h"
#include "sql/session/ob_sql_session_info.h"
namespace oceanbase
{
namespace sql
{
// get_sys_var(name, scope)
class ObExprGetSysVar: public ObFuncExprOperator
{
public:
static const ObExprOperatorType op_type_;
ObExprGetSysVar();
explicit ObExprGetSysVar(common::ObIAllocator &alloc);
virtual ~ObExprGetSysVar();
virtual int calc_result_type2(ObExprResType &type,
ObExprResType &type1,
ObExprResType &type2,
common::ObExprTypeCtx &type_ctx) const;
// for engine 3.0
virtual int cg_expr(ObExprCGCtx &expr_cg_ctx, const ObRawExpr &raw_expr,
ObExpr &rt_expr) const override;
static int calc_get_sys_val_expr(const ObExpr &expr, ObEvalCtx &ctx,
ObDatum &res_datum);
private:
static int calc_(common::ObObj &result, const common::ObString &var_name,
const int64_t var_scope, ObSQLSessionInfo *session,
ObExecContext *exec_ctx, common::ObIAllocator &alloc);
static int get_session_var(common::ObObj &result, const common::ObString &var_name,
common::ObIAllocator &alloc, ObSQLSessionInfo *session,
ObExecContext *exec_ctx);
static int get_sys_var_disp_obj(common::ObIAllocator &allocator,
const ObSQLSessionInfo &session,
const common::ObString &var_name,
common::ObObj &disp_obj);
private:
// disallow copy
DISALLOW_COPY_AND_ASSIGN(ObExprGetSysVar);
};
} // end namespace sql
} // end namespace oceanbase
#endif /* _OB_EXPR_GET_SYS_VAR_H */