Written every time a statement uses a user variable; precedes other events for the statement. More...

#include <statement_events.h>

Inheritance diagram for mysql::binlog::event::User_var_event:

Public Types
enum	{ UNDEF_F , UNSIGNED_F }

enum	User_var_event_data { UV_VAL_LEN_SIZE = 4 , UV_VAL_IS_NULL = 1 , UV_VAL_TYPE_SIZE = 1 , UV_NAME_LEN_SIZE = 4 , UV_CHARSET_NUMBER_SIZE = 4 }

using	Value_type = Item_result

Public Types inherited from mysql::binlog::event::Binary_log_event
enum	enum_post_header_length { QUERY_HEADER_MINIMAL_LEN = (4 + 4 + 1 + 2) , QUERY_HEADER_LEN = (QUERY_HEADER_MINIMAL_LEN + 2) , STOP_HEADER_LEN = 0 , START_V3_HEADER_LEN = (2 + ST_SERVER_VER_LEN + 4) , ROTATE_HEADER_LEN = 8 , INTVAR_HEADER_LEN = 0 , APPEND_BLOCK_HEADER_LEN = 4 , DELETE_FILE_HEADER_LEN = 4 , RAND_HEADER_LEN = 0 , USER_VAR_HEADER_LEN = 0 , FORMAT_DESCRIPTION_HEADER_LEN = (START_V3_HEADER_LEN + 1 + LOG_EVENT_TYPES) , XID_HEADER_LEN = 0 , BEGIN_LOAD_QUERY_HEADER_LEN = APPEND_BLOCK_HEADER_LEN , ROWS_HEADER_LEN_V1 = 8 , TABLE_MAP_HEADER_LEN = 8 , EXECUTE_LOAD_QUERY_EXTRA_HEADER_LEN = (4 + 4 + 4 + 1) , EXECUTE_LOAD_QUERY_HEADER_LEN , INCIDENT_HEADER_LEN = 2 , HEARTBEAT_HEADER_LEN = 0 , IGNORABLE_HEADER_LEN = 0 , ROWS_HEADER_LEN_V2 = 10 , TRANSACTION_CONTEXT_HEADER_LEN = 18 , VIEW_CHANGE_HEADER_LEN = 52 , XA_PREPARE_HEADER_LEN = 0 , TRANSACTION_PAYLOAD_HEADER_LEN = 0 }
	The lengths for the fixed data part of each event. More...

Public Member Functions
	User_var_event (const char name_arg, unsigned int name_len_arg, char val_arg, unsigned long val_len_arg, Value_type type_arg, unsigned int charset_number_arg, unsigned char flags_arg)
	This constructor will initialize the instance variables and the type_code, it will be used only by the server code. More...

	User_var_event (const char buf, const Format_description_event fde)
	The constructor receives a buffer and instantiates a User_var_event filled in with the data from the buffer Written every time a statement uses a user variable, precedes other events for the statement. More...

	~User_var_event () override

Public Member Functions inherited from mysql::binlog::event::Binary_log_event
virtual	~Binary_log_event ()=0

	Binary_log_event (const Binary_log_event &)=default

	Binary_log_event (Binary_log_event &&)=default

Binary_log_event &	operator= (const Binary_log_event &)=default

Binary_log_event &	operator= (Binary_log_event &&)=default

enum Log_event_type	get_event_type () const
	Helper method. More...

const Log_event_header *	header () const
	Return a const pointer to the header of the log event. More...

Log_event_header *	header ()
	Return a non-const pointer to the header of the log event. More...

const Log_event_footer *	footer () const
	Return a const pointer to the footer of the log event. More...

Log_event_footer *	footer ()
	Return a non-const pointer to the footer of the log event. More...

Event_reader &	reader ()
	Returns a reference to the event Event_reader object. More...

Public Attributes
const char *	name

unsigned int	name_len

char *	val

uint32_t	val_len

Value_type	type

unsigned int	charset_number

bool	is_null

unsigned char	flags

Additional Inherited Members
Static Public Attributes inherited from mysql::binlog::event::Binary_log_event
static const int	LOG_EVENT_TYPES = (ENUM_END_EVENT - 1)

Protected Member Functions inherited from mysql::binlog::event::Binary_log_event
	Binary_log_event (Log_event_type type_code)
	This constructor is used to initialize the type_code of header object m_header. More...

	Binary_log_event (const char *buf, const Format_description_event fde)
	This constructor will create a new object of Log_event_header and initialize the variable m_header, which in turn will be used to initialize Log_event's member common_header. More...

Detailed Description

Written every time a statement uses a user variable; precedes other events for the statement.

Indicates the value to use for the user variable in the next statement. This is written only before a QUERY_EVENT and is not used with row-based logging

The Post-Header has following components:

Post-Header for Format_description_event
Name	Format	Description
Value_type	enum	The user variable type.
User_var_event_data	enum	User_var event data
name	const char pointer	User variable name.
name_len	unsigned int	Length of the user variable name
val	char pointer	value of the user variable.
val_len	unsigned long	Length of the value of the user variable
type	enum Value_type	Type of the user variable
charset_number	unsigned int	The number of the character set for the user variable (needed for a string variable). The character set number is really a collation number that indicates a character set/collation pair.
is_null	bool	Non-zero if the variable value is the SQL NULL value, 0 otherwise.

Member Typedef Documentation

◆ Value_type

using mysql::binlog::event::User_var_event::Value_type = Item_result

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Enumerator
UNDEF_F
UNSIGNED_F

◆ User_var_event_data

enum mysql::binlog::event::User_var_event::User_var_event_data

Enumerator
UV_VAL_LEN_SIZE
UV_VAL_IS_NULL
UV_VAL_TYPE_SIZE
UV_NAME_LEN_SIZE
UV_CHARSET_NUMBER_SIZE

Constructor & Destructor Documentation

◆ User_var_event() [1/2]

mysql::binlog::event::User_var_event::User_var_event	(	const char *	name_arg,
		unsigned int	name_len_arg,
		char *	val_arg,
		unsigned long	val_len_arg,
		Value_type	type_arg,
		unsigned int	charset_number_arg,
		unsigned char	flags_arg
	)

inline

This constructor will initialize the instance variables and the type_code, it will be used only by the server code.

◆ User_var_event() [2/2]

mysql::binlog::event::User_var_event::User_var_event	(	const char *	buf,
		const Format_description_event *	fde
	)

The constructor receives a buffer and instantiates a User_var_event filled in with the data from the buffer Written every time a statement uses a user variable, precedes other events for the statement.

Indicates the value to use for the user variable in the next statement. This is written only before a QUERY_EVENT and is not used with row-based logging.

The buffer layout for variable data part is as follows:

+-------------------------------------------------------------------+
| name_len | name | is_null | type | charset_number | val_len | val |
+-------------------------------------------------------------------+

Parameters

buf	Contains the serialized event.
fde	An FDE event (see Rotate_event constructor for more info).

We need to check if this is from an old server that did not pack information for flags. We do this by checking if there are extra bytes after the packed value. If there are we take the extra byte and it's value is assumed to contain the flags value.

Old events will not have this extra byte, thence, we keep the flags set to UNDEF_F.

◆ ~User_var_event()

mysql::binlog::event::User_var_event::~User_var_event ( )

override

Member Data Documentation

◆ charset_number

unsigned int mysql::binlog::event::User_var_event::charset_number

◆ flags

unsigned char mysql::binlog::event::User_var_event::flags

◆ is_null

bool mysql::binlog::event::User_var_event::is_null

◆ name

const char* mysql::binlog::event::User_var_event::name

◆ name_len

unsigned int mysql::binlog::event::User_var_event::name_len

◆ type

Value_type mysql::binlog::event::User_var_event::type

◆ val

char* mysql::binlog::event::User_var_event::val

◆ val_len

uint32_t mysql::binlog::event::User_var_event::val_len

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

libs/mysql/binlog/event/statement_events.h
libs/mysql/binlog/event/statement_events.cpp

Public Types

Public Member Functions

Public Attributes

Additional Inherited Members