Sys_var_session_special Class Reference

#include <sys_vars.h>

Inheritance diagram for Sys_var_session_special:

List of all members.

Public Member Functions
	Sys_var_session_special (const char *name_arg, const char *comment, int flag_args, CMD_LINE getopt, ulonglong min_val, ulonglong max_val, ulonglong block_size, PolyLock *lock, enum binlog_status_enum binlog_status_arg, on_check_function on_check_func, session_special_update_function update_func_arg, session_special_read_function read_func_arg, const char *substitute=0)
bool	session_update (THD *thd, set_var *var)
bool	global_update (THD *thd, set_var *var)
void	session_save_default (THD *thd, set_var *var)
void	global_save_default (THD *thd, set_var *var)
uchar *	session_value_ptr (THD *thd, LEX_STRING *base)
uchar *	global_value_ptr (THD *thd, LEX_STRING *base)

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Detailed Description

The class for variables that have a special meaning for a session, such as @timestamp or @rnd_seed1, their values typically cannot be read from SV structure, and a special "read" callback is provided.

Class specific constructor arguments: everything derived from Sys_var_ulonglong session_special_read_function read_func_arg

Backing store: ulonglong

Note:

These variables are session-only, global or command-line equivalents are not supported as they're generally meaningless.

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Member Function Documentation

void Sys_var_session_special::global_save_default	(	THD *	thd,
		set_var *	var
	)		[inline, virtual]

save the global default value of the variable in var

Reimplemented from Sys_var_integer< T, ARGT, SHOWT, SIGNED >.

void Sys_var_session_special::session_save_default	(	THD *	thd,
		set_var *	var
	)		[inline, virtual]

save the session default value of the variable in var

Reimplemented from Sys_var_integer< T, ARGT, SHOWT, SIGNED >.

uchar* Sys_var_session_special::session_value_ptr	(	THD *	thd,
		LEX_STRING *	base
	)		[inline, virtual]

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.

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

• sys_vars.h