table_variables_info.h

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/* Copyright (c) 2016, 2024, Oracle and/or its affiliates.
 
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  it under the terms of the GNU General Public License, version 2.0,
  as published by the Free Software Foundation.
 
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#ifndef TABLE_VARIABLES_INFO_H
#define TABLE_VARIABLES_INFO_H
 
/**
  @file storage/perfschema/table_variables_info.h
  Table VARIABLES_INFO (declarations).
*/
 
#include <sys/types.h>
 
#include "my_base.h"
#include "my_inttypes.h"
#include "mysql/components/services/system_variable_source_type.h"
#include "mysql_com.h"
#include "storage/perfschema/pfs_column_types.h"
#include "storage/perfschema/pfs_engine_table.h"
#include "storage/perfschema/pfs_variable.h"
 
class Field;
class Plugin_table;
struct TABLE;
struct THR_LOCK;
 
/**
  A row of table
  PERFORMANCE_SCHEMA.VARIABLES_INFO.
*/
struct row_variables_info {
  /** Column VARIABLE_NAME. */
  char m_variable_name[COL_SOURCE_SIZE];
  uint m_variable_name_length;
  /** Column VARIABLE_SOURCE. */
  enum_variable_source m_variable_source;
  /** Column VARIABLE_PATH. */
  char m_variable_path[COL_INFO_SIZE];
  uint m_variable_path_length;
  /** Column MIN_VALUE. */
  char m_min_value[COL_SOURCE_SIZE];
  uint m_min_value_length;
  /** Column MAX_VALUE. */
  char m_max_value[COL_SOURCE_SIZE];
  uint m_max_value_length;
  /** Column SET_TIME. */
  ulonglong m_set_time;
  /** Column SET_USER. */
  char m_set_user_str[USERNAME_LENGTH];
  uint m_set_user_str_length;
  /** Column SET_HOST. */
  char m_set_host_str[HOSTNAME_LENGTH];
  uint m_set_host_str_length;
};
 
/** Table PERFORMANCE_SCHEMA.VARIABLES_INFO. */
class table_variables_info : public PFS_engine_table {
  typedef PFS_simple_index pos_t;
 
 public:
  /** Table share */
  static PFS_engine_table_share m_share;
  static PFS_engine_table *create(PFS_engine_table_share *);
  static ha_rows get_row_count();
 
  int rnd_init(bool scan) override;
  int rnd_next() override;
  int rnd_pos(const void *pos) override;
  void reset_position() override;
 
 protected:
  int read_row_values(TABLE *table, unsigned char *buf, Field **fields,
                      bool read_all) override;
  table_variables_info();
 
 public:
  ~table_variables_info() override = default;
 
 protected:
  int make_row(const System_variable *system_var);
 
 private:
  /** Table share lock. */
  static THR_LOCK m_table_lock;
  /** Table definition. */
  static Plugin_table m_table_def;
 
  /** Current THD variables. */
  PFS_system_variable_info_cache m_sysvarinfo_cache;
  /** Current row. */
  row_variables_info m_row;
  /** Current position. */
  pos_t m_pos;
  /** Next position. */
  pos_t m_next_pos;
};
 
#endif