MySQL 9.0.0
Source Code Documentation
Sys_var_plugin Class Reference

The class for variables which value is a plugin. More...

#include <sys_vars.h>

Inheritance diagram for Sys_var_plugin:

Public Member Functions

 Sys_var_plugin (const char *name_arg, const char *comment, int flag_args, ptrdiff_t off, size_t size, CMD_LINE getopt, int plugin_type_arg, const char **def_val, PolyLock *lock=nullptr, enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG, on_check_function on_check_func=nullptr, on_update_function on_update_func=nullptr, const char *substitute=nullptr, int parse_flag=PARSE_NORMAL)
bool do_check (THD *thd, set_var *var) override
void do_update (plugin_ref *valptr, plugin_ref newval)
bool session_update (THD *thd, set_var *var) override
bool global_update (THD *, set_var *var) override
void session_save_default (THD *thd, set_var *var) override
 save the session default value of the variable in var More...
void global_save_default (THD *thd, set_var *var) override
 save the global default value of the variable in var More...
void saved_value_to_string (THD *, set_var *var, char *def_val) override
 This function converts value stored in save_result to string. More...
bool check_update_type (Item_result type) override
const ucharsession_value_ptr (THD *running_thd, THD *target_thd, std::string_view) override
 A pointer to a value of the variable for SHOW. More...
const ucharglobal_value_ptr (THD *thd, std::string_view) override
- Public Member Functions inherited from sys_var
 sys_var (sys_var_chain *chain, const char *name_arg, const char *comment, int flag_args, ptrdiff_t off, int getopt_id, enum get_opt_arg_type getopt_arg_type, SHOW_TYPE show_val_type_arg, longlong def_val, PolyLock *lock, enum binlog_status_enum binlog_status_arg, on_check_function on_check_func, on_update_function on_update_func, const char *substitute, int parse_flag, sys_var *persisted_alias=nullptr, bool is_persisted_deprecated=false)
 sys_var constructor More...
virtual ~sys_var ()=default
const char * get_deprecation_substitute ()
virtual void cleanup ()
 All the cleanup procedures should be performed here. More...
virtual sys_var_pluginvarcast_pluginvar ()
 downcast for sys_var_pluginvar. More...
bool check (THD *thd, set_var *var)
const ucharvalue_ptr (THD *running_thd, THD *target_thd, enum_var_type type, std::string_view keycache_name)
const ucharvalue_ptr (THD *thd, enum_var_type type, std::string_view keycache_name)
virtual void update_default (longlong new_def_value)
virtual longlong get_default ()
virtual longlong get_min_value ()
virtual ulonglong get_max_value ()
virtual ulong get_var_type ()
 Returns variable type. More...
virtual void set_arg_source (get_opt_arg_source *)
virtual void set_is_plugin (bool)
virtual enum_variable_source get_source ()
virtual const char * get_source_name ()
virtual void set_source (enum_variable_source src)
virtual bool set_source_name (const char *path)
virtual bool set_user (const char *usr)
virtual const char * get_user ()
virtual const char * get_host ()
virtual bool set_host (const char *hst)
virtual ulonglong get_timestamp () const
virtual void set_user_host (THD *thd)
my_optionget_option ()
virtual void set_timestamp ()
virtual void set_timestamp (ulonglong ts)
virtual bool is_non_persistent ()
bool set_default (THD *thd, set_var *var)
 Update the system variable with the default value from either session or global scope. More...
bool update (THD *thd, set_var *var)
SHOW_TYPE show_type ()
int scope () const
const CHARSET_INFOcharset (THD *thd)
bool is_readonly () const
bool not_visible () const
bool is_trilevel () const
bool is_persist_readonly () const
bool is_parse_early () const
bool is_sensitive () const
bool is_hint_updateable () const
 Check if the variable can be set using SET_VAR hint. More...
bool is_struct ()
 the following is only true for keycache variables, that support the syntax @keycache_name.variable_name More...
bool is_written_to_binlog (enum_var_type type)
bool check_scope (enum_var_type query_type)
 Return true for success if: Global query and variable scope is GLOBAL or SESSION, or Session query and variable scope is SESSION or ONLY_SESSION. More...
bool is_global_persist (enum_var_type type)
bool is_settable_at_command_line ()
 Return true if settable at the command line. More...
bool register_option (std::vector< my_option > *array, int parse_flags)
void do_deprecated_warning (THD *thd)
Itemcopy_value (THD *thd)
 Create item from system variable value. More...
void save_default (THD *thd, set_var *var)
bool check_if_sensitive_in_context (THD *, bool suppress_errors=true) const

Private Attributes

int plugin_type

Additional Inherited Members

- Public Types inherited from sys_var
enum  flag_enum {
  GLOBAL = 0x0001 , SESSION = 0x0002 , ONLY_SESSION = 0x0004 , SCOPE_MASK = 0x03FF ,
  READONLY = 0x0400 , ALLOCATED = 0x0800 , INVISIBLE = 0x1000 , TRI_LEVEL = 0x2000 ,
  NOTPERSIST = 0x4000 , HINT_UPDATEABLE = 0x8000 , PERSIST_AS_READ_ONLY = 0x10000 , SENSITIVE = 0x20000
 Enumeration type to indicate for a system variable whether it will be written to the binlog or not. More...
- Public Attributes inherited from sys_var
 If the variable has an alias in the persisted variables file, this should point to it. More...
bool m_is_persisted_deprecated
 If m_persist_alias is set, and the current variable is deprecated and m_persist_alias is the recommended substitute, then this flag should be set to true. More...
enum sys_var::binlog_status_enum binlog_status
 Global system variable attributes. More...
std::map< std::string, std::string > m_global_attributes
- Static Public Attributes inherited from sys_var
static const int PARSE_EARLY = 1
static const int PARSE_NORMAL = 2
- Protected Types inherited from sys_var
typedef bool(* on_check_function) (sys_var *self, THD *thd, set_var *var)
typedef bool(* pre_update_function) (sys_var *self, THD *thd, set_var *var)
typedef bool(* on_update_function) (sys_var *self, THD *thd, enum_var_type type)
- Protected Member Functions inherited from sys_var
ucharsession_var_ptr (THD *thd)
 A pointer to a storage area of the variable, to the raw data. More...
ucharglobal_var_ptr ()
- Protected Attributes inherited from sys_var
int flags
 or'ed flag_enum values More...
int m_parse_flag
 either PARSE_EARLY or PARSE_NORMAL. More...
const SHOW_TYPE show_val_type
 what value_ptr() returns for More...
my_option option
 min, max, default values are stored here More...
 second lock that protects the variable More...
ptrdiff_t offset
 offset to the value from global_system_variables More...
on_check_function on_check
pre_update_function pre_update
 Pointer to function to be invoked before updating system variable (but after calling on_check hook), while we do not hold any locks yet. More...
on_update_function on_update
const char *const deprecation_substitute
bool is_os_charset
 true if the value is in character_set_filesystem More...
struct get_opt_arg_source source
char host [HOSTNAME_LENGTH+1]
ulonglong timestamp

Detailed Description

The class for variables which value is a plugin.

Example: @default_storage_engine

Class specific constructor arguments: int plugin_type_arg (for example MYSQL_STORAGE_ENGINE_PLUGIN)

Backing store: plugin_ref

these variables don't support command-line equivalents, any such command-line options should be added manually to my_long_options in

Constructor & Destructor Documentation

◆ Sys_var_plugin()

Sys_var_plugin::Sys_var_plugin ( const char *  name_arg,
const char *  comment,
int  flag_args,
ptrdiff_t  off,
size_t  size,
CMD_LINE  getopt,
int  plugin_type_arg,
const char **  def_val,
PolyLock lock = nullptr,
enum binlog_status_enum  binlog_status_arg = VARIABLE_NOT_IN_BINLOG,
on_check_function  on_check_func = nullptr,
on_update_function  on_update_func = nullptr,
const char *  substitute = nullptr,
int  parse_flag = PARSE_NORMAL 

Member Function Documentation

◆ check_update_type()

bool Sys_var_plugin::check_update_type ( Item_result  type)

Implements sys_var.

◆ do_check()

bool Sys_var_plugin::do_check ( THD thd,
set_var var 

Implements sys_var.

◆ do_update()

void Sys_var_plugin::do_update ( plugin_ref valptr,
plugin_ref  newval 

◆ global_save_default()

void Sys_var_plugin::global_save_default ( THD thd,
set_var var 

save the global default value of the variable in var

Implements sys_var.

◆ global_update()

bool Sys_var_plugin::global_update ( THD ,
set_var var 

Implements sys_var.

◆ global_value_ptr()

const uchar * Sys_var_plugin::global_value_ptr ( THD thd,

Reimplemented from sys_var.

◆ saved_value_to_string()

void Sys_var_plugin::saved_value_to_string ( THD thd,
set_var var,
char *  def_val 

This function converts value stored in save_result to string.

This function must be called after calling save_default() as save_default() will store default value to save_result.

Implements sys_var.

◆ session_save_default()

void Sys_var_plugin::session_save_default ( THD thd,
set_var var 

save the session default value of the variable in var

Implements sys_var.

◆ session_update()

bool Sys_var_plugin::session_update ( THD thd,
set_var var 

Implements sys_var.

◆ session_value_ptr()

const uchar * Sys_var_plugin::session_value_ptr ( THD running_thd,
THD target_thd,
std::string_view  keycache_name 

A pointer to a value of the variable for SHOW.

It must be of show_val_type type (bool for SHOW_BOOL, int for SHOW_INT, longlong for SHOW_LONGLONG, etc).

Reimplemented from sys_var.

Member Data Documentation

◆ plugin_type

int Sys_var_plugin::plugin_type

The documentation for this class was generated from the following file: