A class representing one system variable - that is something that can be accessed as @global.variable_name or @session.variable_name, visible in SHOW xxx VARIABLES and in INFORMATION_SCHEMA.xxx_VARIABLES, optionally it can be assigned to, optionally it can have a command-line counterpart with the same name. More...

#include <set_var.h>

Inheritance diagram for sys_var:

[legend]

Public Types
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 }

enum	binlog_status_enum { VARIABLE_NOT_IN_BINLOG , SESSION_VARIABLE_IN_BINLOG }
	Enumeration type to indicate for a system variable whether it will be written to the binlog or not. More...

Public Member Functions
	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_pluginvar *	cast_pluginvar ()
	downcast for sys_var_pluginvar. More...

bool	check (THD thd, set_var var)

const uchar *	value_ptr (THD running_thd, THD target_thd, enum_var_type type, std::string_view keycache_name)

const uchar *	value_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_option *	get_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)

virtual void	saved_value_to_string (THD thd, set_var var, char *def_val)=0
	This function converts value stored in save_result to string. More...

SHOW_TYPE	show_type ()

int	scope () const

const CHARSET_INFO *	charset (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)

virtual bool	check_update_type (Item_result type)=0

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)

Item *	copy_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

Public Attributes
sys_var *	next

LEX_CSTRING	name

sys_var *	m_persisted_alias
	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
static const int	PARSE_EARLY = 1

static const int	PARSE_NORMAL = 2

Protected Types
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
virtual const uchar *	session_value_ptr (THD running_thd, THD target_thd, std::string_view keycache_name)
	A pointer to a value of the variable for SHOW. More...

virtual const uchar *	global_value_ptr (THD *thd, std::string_view keycache_name)

uchar *	session_var_ptr (THD *thd)
	A pointer to a storage area of the variable, to the raw data. More...

uchar *	global_var_ptr ()

Protected Attributes
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 sql_show.cc More...

my_option	option
	min, max, default values are stored here More...

PolyLock *	guard
	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	user [USERNAME_CHAR_LENGTH+1]

char	host [HOSTNAME_LENGTH+1]

ulonglong	timestamp

Private Member Functions
virtual bool	do_check (THD thd, set_var var)=0

virtual void	session_save_default (THD thd, set_var var)=0
	save the session default value of the variable in var More...

virtual void	global_save_default (THD thd, set_var var)=0
	save the global default value of the variable in var More...

virtual bool	session_update (THD thd, set_var var)=0

virtual bool	global_update (THD thd, set_var var)=0

Static Private Member Functions
static bool	set_and_truncate (char dst, const char string, size_t sizeof_dst)
	Like strncpy, but ensures the destination is '\0'-terminated. More...

Friends
class	Sys_var_alias

Detailed Description

A class representing one system variable - that is something that can be accessed as @global.variable_name or @session.variable_name, visible in SHOW xxx VARIABLES and in INFORMATION_SCHEMA.xxx_VARIABLES, optionally it can be assigned to, optionally it can have a command-line counterpart with the same name.

Member Typedef Documentation

◆ on_check_function

typedef bool(* sys_var::on_check_function) (sys_var *self, THD *thd, set_var *var)

protected

◆ on_update_function

typedef bool(* sys_var::on_update_function) (sys_var *self, THD *thd, enum_var_type type)

protected

◆ pre_update_function

typedef bool(* sys_var::pre_update_function) (sys_var *self, THD *thd, set_var *var)

protected

Member Enumeration Documentation

◆ binlog_status_enum

enum sys_var::binlog_status_enum

Enumeration type to indicate for a system variable whether it will be written to the binlog or not.

Enumerator
VARIABLE_NOT_IN_BINLOG
SESSION_VARIABLE_IN_BINLOG

◆ flag_enum

enum sys_var::flag_enum

Enumerator
GLOBAL
SESSION
ONLY_SESSION
SCOPE_MASK
READONLY
ALLOCATED
INVISIBLE
TRI_LEVEL
NOTPERSIST
HINT_UPDATEABLE
PERSIST_AS_READ_ONLY	There can be some variables which needs to be set before plugin is loaded. ex: binlog_checksum needs to be set before GR plugin is loaded. Also, there are some variables which needs to be set before some server internal component initialization. ex: binlog_encryption needs to be set before binary and relay log files generation.
SENSITIVE	Sensitive variable. If keyring is available, the variable will be persisted in mysqld-auto.cnf in encrypted format

Constructor & Destructor Documentation

◆ sys_var()

sys_var::sys_var	(	sys_var_chain *	chain,
		const char *	name_arg,
		const char *	comment,
		int	flags_arg,
		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

Parameters

chain	variables are linked into chain for add_static_system_variable_chain() or add_dynamic_system_variable_chain()
name_arg	the name of the variable. Must be 0-terminated and exist for the lifetime of the sys_var object.

See also: my_option::name

Parameters

comment shown in mysqld –help,

See also: my_option::comment

Parameters

flags_arg	or'ed flag_enum values
off	offset of the global variable value from the &global_system_variables.
getopt_id	-1 for no command-line option, otherwise

See also: my_option::id

Parameters

getopt_arg_type no|optional|required value

See also: my_option::arg_type

Parameters

show_val_type_arg	what value_ptr() returns for sql_show.cc
def_val	default value,

See also: my_option::def_value

Parameters

lock	mutex or rw_lock that protects the global variable in addition* to LOCK_global_system_variables.
binlog_status_arg	if the sysvar will be written to binlog or not

See also: binlog_status_enum

Parameters

on_check_func	a function to be called at the end of sys_var::check, put your additional checks here
on_update_func	a function to be called at the end of sys_var::update, any post-update activity should happen here
substitute	If non-NULL, this variable is deprecated and the string describes what one should use instead. If an empty string, the variable is deprecated but no replacement is offered.
parse_flag	either PARSE_EARLY or PARSE_NORMAL
persisted_alias	If this variable is persisted, it will appear in the file both under its own name, and using 'persisted_alias'.
is_persisted_deprecated	If this variable is found in the persisted, variables file, and its alias is not found, a deprecation warning will be issued if is_persisted_deprecated is true. This flag must be false if persisted_alias is null.

◆ ~sys_var()

virtual sys_var::~sys_var ( )

virtualdefault

Member Function Documentation

◆ cast_pluginvar()

virtual sys_var_pluginvar * sys_var::cast_pluginvar ( )

inlinevirtual

downcast for sys_var_pluginvar.

Returns this if it's an instance of sys_var_pluginvar, and 0 otherwise.

Reimplemented in sys_var_pluginvar, and Sys_var_alias.

◆ charset()

const CHARSET_INFO * sys_var::charset ( THD * thd )

◆ check()

bool sys_var::check	(	THD *	thd,
		set_var *	var
	)

◆ check_if_sensitive_in_context()

bool sys_var::check_if_sensitive_in_context	(	THD *	thd,
		bool	suppress_errors = `true`
	)		const

◆ check_scope()

bool sys_var::check_scope ( enum_var_type query_type )

inline

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.

◆ check_update_type()

virtual bool sys_var::check_update_type ( Item_result type )

pure virtual

Implemented in sys_var_pluginvar, Sys_var_integer< T, ARGT, SHOWT, SIGNED >, Sys_var_alias, Sys_var_typelib, Sys_var_multi_enum, Sys_var_charptr, Sys_var_dbug, Sys_var_double, Sys_var_plugin, Sys_var_struct< Struct_type, Name_getter >, Sys_var_tz, Sys_var_gtid_next, Sys_var_gtid_purged, Sys_var_proxy_user, Sys_var_have, and Sys_var_charptr_func.

◆ cleanup()

virtual void sys_var::cleanup ( )

inlinevirtual

All the cleanup procedures should be performed here.

Reimplemented in Sys_var_alias, and Sys_var_charptr.

◆ copy_value()

Item * sys_var::copy_value ( THD * thd )

Create item from system variable value.

Parameters

thd	pointer to THD object

Returns: pointer to Item object or NULL if it's impossible to obtain the value.

◆ do_check()

virtual bool sys_var::do_check	(	THD *	thd,
		set_var *	var
	)

privatepure virtual

Implemented in Sys_var_proxy_user, Sys_var_have, Sys_var_struct< Struct_type, Name_getter >, Sys_var_gtid_next, Sys_var_charptr_func, Sys_var_typelib, Sys_var_multi_enum, Sys_var_set, sys_var_pluginvar, Sys_var_integer< T, ARGT, SHOWT, SIGNED >, Sys_var_alias, Sys_var_charptr, Sys_var_dbug, Sys_var_double, Sys_var_flagset, Sys_var_plugin, Sys_var_tz, and Sys_var_gtid_purged.

◆ do_deprecated_warning()

void sys_var::do_deprecated_warning ( THD * thd )

◆ get_default()

virtual longlong sys_var::get_default ( )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ get_deprecation_substitute()

const char * sys_var::get_deprecation_substitute ( )

inline

◆ get_host()

virtual const char * sys_var::get_host ( )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ get_max_value()

virtual ulonglong sys_var::get_max_value ( )

inlinevirtual

Reimplemented in sys_var_pluginvar, and Sys_var_alias.

◆ get_min_value()

virtual longlong sys_var::get_min_value ( )

inlinevirtual

Reimplemented in sys_var_pluginvar, and Sys_var_alias.

◆ get_option()

my_option * sys_var::get_option ( )

inline

◆ get_source()

virtual enum_variable_source sys_var::get_source ( )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ get_source_name()

virtual const char * sys_var::get_source_name ( )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ get_timestamp()

virtual ulonglong sys_var::get_timestamp ( ) const

inlinevirtual

Reimplemented in Sys_var_alias.

◆ get_user()

virtual const char * sys_var::get_user ( )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ get_var_type()

virtual ulong sys_var::get_var_type ( )

inlinevirtual

Returns variable type.

Returns: variable type

Reimplemented in Sys_var_alias.

◆ global_save_default()

virtual void sys_var::global_save_default	(	THD *	thd,
		set_var *	var
	)

privatepure virtual

save the global default value of the variable in var

Implemented in sys_var_pluginvar, Sys_var_proxy_user, Sys_var_session_special, Sys_var_session_special_double, Sys_var_have, Sys_var_gtid_next, Sys_var_charptr_func, Sys_var_gtid_purged, Sys_var_integer< T, ARGT, SHOWT, SIGNED >, Sys_var_enum, Sys_var_bool, Sys_var_multi_enum, Sys_var_charptr, Sys_var_dbug, Sys_var_double, Sys_var_flagset, Sys_var_set, Sys_var_bit, Sys_var_struct< Struct_type, Name_getter >, Sys_var_tz, Sys_var_alias, and Sys_var_plugin.

◆ global_update()

virtual bool sys_var::global_update	(	THD *	thd,
		set_var *	var
	)

privatepure virtual

◆ global_value_ptr()

const uchar * sys_var::global_value_ptr	(	THD *	thd,
		std::string_view	keycache_name
	)

protectedvirtual

◆ global_var_ptr()

uchar * sys_var::global_var_ptr ( )

protected

◆ is_global_persist()

bool sys_var::is_global_persist ( enum_var_type type )

inline

◆ is_hint_updateable()

bool sys_var::is_hint_updateable ( ) const

inline

Check if the variable can be set using SET_VAR hint.

Returns: true if the variable can be set using SET_VAR hint, false otherwise.

◆ is_non_persistent()

virtual bool sys_var::is_non_persistent ( )

inlinevirtual

Reimplemented in sys_var_pluginvar, and Sys_var_alias.

◆ is_parse_early()

bool sys_var::is_parse_early ( ) const

inline

◆ is_persist_readonly()

bool sys_var::is_persist_readonly ( ) const

inline

◆ is_readonly()

bool sys_var::is_readonly ( ) const

inline

◆ is_sensitive()

bool sys_var::is_sensitive ( ) const

inline

◆ is_settable_at_command_line()

bool sys_var::is_settable_at_command_line ( )

inline

Return true if settable at the command line.

◆ is_struct()

bool sys_var::is_struct ( )

inline

the following is only true for keycache variables, that support the syntax @keycache_name.variable_name

◆ is_trilevel()

bool sys_var::is_trilevel ( ) const

inline

◆ is_written_to_binlog()

bool sys_var::is_written_to_binlog ( enum_var_type type )

inline

◆ not_visible()

bool sys_var::not_visible ( ) const

inline

◆ register_option()

bool sys_var::register_option	(	std::vector< my_option > *	array,
		int	parse_flags
	)

inline

◆ save_default()

void sys_var::save_default	(	THD *	thd,
		set_var *	var
	)

inline

◆ saved_value_to_string()

virtual void sys_var::saved_value_to_string	(	THD *	thd,
		set_var *	var,
		char *	def_val
	)

pure virtual

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.

Implemented in Sys_var_proxy_user, Sys_var_session_special, Sys_var_session_special_double, Sys_var_have, Sys_var_gtid_next, Sys_var_charptr_func, Sys_var_gtid_purged, Sys_var_integer< T, ARGT, SHOWT, SIGNED >, Sys_var_enum, Sys_var_bool, Sys_var_multi_enum, Sys_var_charptr, Sys_var_dbug, Sys_var_double, Sys_var_plugin, Sys_var_bit, Sys_var_struct< Struct_type, Name_getter >, Sys_var_tz, sys_var_pluginvar, Sys_var_alias, Sys_var_flagset, and Sys_var_set.

◆ scope()

int sys_var::scope ( ) const

inline

◆ session_save_default()

virtual void sys_var::session_save_default	(	THD *	thd,
		set_var *	var
	)

privatepure virtual

save the session default value of the variable in var

Implemented in sys_var_pluginvar, Sys_var_multi_enum, Sys_var_proxy_user, Sys_var_dbug, Sys_var_have, Sys_var_charptr_func, Sys_var_gtid_purged, Sys_var_enum, Sys_var_charptr, Sys_var_double, Sys_var_flagset, Sys_var_set, Sys_var_bit, Sys_var_session_special, Sys_var_session_special_double, Sys_var_struct< Struct_type, Name_getter >, Sys_var_tz, Sys_var_gtid_next, Sys_var_integer< T, ARGT, SHOWT, SIGNED >, Sys_var_alias, Sys_var_bool, and Sys_var_plugin.

◆ session_update()

virtual bool sys_var::session_update	(	THD *	thd,
		set_var *	var
	)

privatepure virtual

◆ session_value_ptr()

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

protectedvirtual

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 in Sys_var_multi_enum, Sys_var_have, Sys_var_charptr_func, Sys_var_gtid_purged, Sys_var_enum, Sys_var_proxy_user, Sys_var_external_user, Sys_var_struct< Struct_type, Name_getter >, Sys_var_tz, Sys_var_dbug, sys_var_pluginvar, Sys_var_alias, Sys_var_max_user_conn, Sys_var_flagset, Sys_var_set, Sys_var_plugin, Sys_var_bit, Sys_var_session_special, Sys_var_session_special_double, Sys_var_gtid_next, and Sys_var_gtid_owned.

◆ session_var_ptr()

uchar * sys_var::session_var_ptr ( THD * thd )

protected

A pointer to a storage area of the variable, to the raw data.

Typically it's the same as session_value_ptr(), but it's different, for example, for ENUM, that is printed as a string, but stored as a number.

◆ set_and_truncate()

static bool sys_var::set_and_truncate	(	char *	dst,
		const char *	string,
		size_t	sizeof_dst
	)

inlinestaticprivate

Like strncpy, but ensures the destination is '\0'-terminated.

Is also safe to call if dst==string (but not if they overlap in any other way).

Parameters

dst	Target string
string	Source string
sizeof_dst	Size of the dst buffer

Return values

false	The entire string was copied to dst
true	strlen(string) was bigger than or equal to sizeof_dst, so dst contains only the sizeof_dst-1 first characters of string.

◆ set_arg_source()

virtual void sys_var::set_arg_source ( get_opt_arg_source * )

inlinevirtual

Reimplemented in Sys_var_alias, and sys_var_pluginvar.

◆ set_default()

bool sys_var::set_default	(	THD *	thd,
		set_var *	var
	)

Update the system variable with the default value from either session or global scope.

The default value is stored in the 'var' argument. Return false when successful.

◆ set_host()

virtual bool sys_var::set_host ( const char * hst )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ set_is_plugin()

virtual void sys_var::set_is_plugin ( bool )

inlinevirtual

Reimplemented in Sys_var_alias, and sys_var_pluginvar.

◆ set_source()

virtual void sys_var::set_source ( enum_variable_source src )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ set_source_name()

virtual bool sys_var::set_source_name ( const char * path )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ set_timestamp() [1/2]

virtual void sys_var::set_timestamp ( )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ set_timestamp() [2/2]

virtual void sys_var::set_timestamp ( ulonglong ts )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ set_user()

virtual bool sys_var::set_user ( const char * usr )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ set_user_host()

void sys_var::set_user_host ( THD * thd )

virtual

Reimplemented in Sys_var_alias.

◆ show_type()

SHOW_TYPE sys_var::show_type ( )

inline

◆ update()

bool sys_var::update	(	THD *	thd,
		set_var *	var
	)

◆ update_default()

virtual void sys_var::update_default ( longlong new_def_value )

inlinevirtual

Reimplemented in Sys_var_alias.

◆ value_ptr() [1/2]

const uchar * sys_var::value_ptr	(	THD *	running_thd,
		THD *	target_thd,
		enum_var_type	type,
		std::string_view	keycache_name
	)

◆ value_ptr() [2/2]

const uchar * sys_var::value_ptr	(	THD *	thd,
		enum_var_type	type,
		std::string_view	keycache_name
	)

Friends And Related Function Documentation

◆ Sys_var_alias

friend class Sys_var_alias

friend

Member Data Documentation

◆ binlog_status

enum sys_var::binlog_status_enum sys_var::binlog_status

Global system variable attributes.

◆ deprecation_substitute

const char* const sys_var::deprecation_substitute

protected

◆ flags

int sys_var::flags

protected

or'ed flag_enum values

◆ guard

PolyLock* sys_var::guard

protected

second lock that protects the variable

◆ host

char sys_var::host[HOSTNAME_LENGTH+1]

protected

◆ is_os_charset

bool sys_var::is_os_charset

protected

true if the value is in character_set_filesystem

◆ m_global_attributes

std::map<std::string, std::string> sys_var::m_global_attributes

◆ m_is_persisted_deprecated

bool sys_var::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.

This has the consequence that the code that loads persisted variables will generate a warning if it encounters this variable but does not encounter the alias.

◆ m_parse_flag

int sys_var::m_parse_flag

protected

either PARSE_EARLY or PARSE_NORMAL.

◆ m_persisted_alias

sys_var* sys_var::m_persisted_alias

If the variable has an alias in the persisted variables file, this should point to it.

This has the following consequences:

A SET PERSIST statement that sets either of the variables will persist both variables in the file.
When loading persisted variables, an occurrence of any one of the variables will initialize both variables.

◆ name

LEX_CSTRING sys_var::name

◆ next

sys_var* sys_var::next

◆ offset

ptrdiff_t sys_var::offset

protected

offset to the value from global_system_variables

◆ on_check

on_check_function sys_var::on_check

protected

◆ on_update

on_update_function sys_var::on_update

protected

◆ option

my_option sys_var::option

protected

min, max, default values are stored here

◆ PARSE_EARLY

const int sys_var::PARSE_EARLY = 1

static

◆ PARSE_NORMAL

const int sys_var::PARSE_NORMAL = 2

static

◆ pre_update

pre_update_function sys_var::pre_update

protected

Pointer to function to be invoked before updating system variable (but after calling on_check hook), while we do not hold any locks yet.

◆ show_val_type

const SHOW_TYPE sys_var::show_val_type

protected

what value_ptr() returns for sql_show.cc

◆ source

struct get_opt_arg_source sys_var::source

protected

◆ timestamp

ulonglong sys_var::timestamp

protected

◆ user

char sys_var::user[USERNAME_CHAR_LENGTH+1]

protected

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

sql/set_var.h
sql/set_var.cc

Public Types

Public Member Functions

Public Attributes

Static Public Attributes

Protected Types

Protected Member Functions

Protected Attributes

Private Member Functions

Static Private Member Functions

Friends

Detailed Description

Member Typedef Documentation

◆ on_check_function

◆ on_update_function

◆ pre_update_function

Member Enumeration Documentation

◆ binlog_status_enum

◆ flag_enum

Constructor & Destructor Documentation

◆ sys_var()

◆ ~sys_var()

Member Function Documentation

◆ cast_pluginvar()

◆ charset()

◆ check()

◆ check_if_sensitive_in_context()

◆ check_scope()

◆ check_update_type()

◆ cleanup()

◆ copy_value()

◆ do_check()

◆ do_deprecated_warning()

◆ get_default()

◆ get_deprecation_substitute()

◆ get_host()

◆ get_max_value()

◆ get_min_value()

◆ get_option()

◆ get_source()

◆ get_source_name()

◆ get_timestamp()

◆ get_user()

◆ get_var_type()

◆ global_save_default()

◆ global_update()

◆ global_value_ptr()

◆ global_var_ptr()

◆ is_global_persist()

◆ is_hint_updateable()

◆ is_non_persistent()

◆ is_parse_early()

◆ is_persist_readonly()

◆ is_readonly()

◆ is_sensitive()

◆ is_settable_at_command_line()

◆ is_struct()

◆ is_trilevel()

◆ is_written_to_binlog()

◆ not_visible()

◆ register_option()

◆ save_default()

◆ saved_value_to_string()

◆ scope()

◆ session_save_default()

◆ session_update()

◆ session_value_ptr()

◆ session_var_ptr()

◆ set_and_truncate()

◆ set_arg_source()

◆ set_default()

◆ set_host()

◆ set_is_plugin()

◆ set_source()

◆ set_source_name()

◆ set_timestamp() [1/2]

◆ set_timestamp() [2/2]

◆ set_user()

◆ set_user_host()

◆ show_type()

◆ update()