Every time a query uses the value of a user variable, a User_var_log_event is written before the Query_log_event, to set the user variable. More...

#include <log_event.h>

Inheritance diagram for User_var_log_event:

[legend]

Public Member Functions
	User_var_log_event (THD thd_arg, const char name_arg, uint name_len_arg, char *val_arg, ulong val_len_arg, Item_result type_arg, uint charset_number_arg, uchar flags_arg, enum_event_cache_type cache_type_arg, enum_event_logging_type logging_type_arg)

int	pack_info (Protocol *protocol) override
	Stores a string representation of this event in the Protocol. More...

	User_var_log_event (const char buf, const Format_description_event description_event)

	~User_var_log_event () override=default

void	claim_memory_ownership (bool claim) override
	Allow thread to CLAIM or DISCLAIM the ownership of this object depends on the parameter value passed. More...

bool	write (Basic_ostream *ostream) override

bool	is_deferred ()

void	set_deferred (query_id_t qid)

bool	is_sbr_logging_format () const override
	Return true if the event has to be logged using SBR for DMLs. More...

Public Member Functions inherited from binary_log::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)
	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 binary_log::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 Member Functions inherited from Log_event
	Log_event (Log_event_header header, Log_event_footer footer, enum_event_cache_type cache_type_arg, enum_event_logging_type logging_type_arg)
	This minimal constructor is for when you are not even sure that there is a valid THD. More...

	Log_event (THD thd_arg, uint16 flags_arg, enum_event_cache_type cache_type_arg, enum_event_logging_type logging_type_arg, Log_event_header header, Log_event_footer *footer)

int	net_send (Protocol protocol, const char log_name, my_off_t pos)
	Only called by SHOW BINLOG EVENTS. More...

virtual const char *	get_db ()

void *	operator new (size_t size)

bool	wrapper_my_b_safe_write (Basic_ostream ostream, const uchar buf, size_t data_length)
	Write the given buffer to the given output stream, updating the checksum if checksums are enabled. More...

time_t	get_time ()
	Prints a "session_var=value" string. More...

virtual bool	write_data_header (Basic_ostream *)

virtual bool	write_data_body (Basic_ostream *)

virtual Log_event_type	get_type_code () const

virtual bool	is_rbr_logging_format () const
	Return true if the event has to be logged using RBR for DMLs. More...

bool	is_valid ()

void	set_artificial_event ()

void	set_relay_log_event ()

bool	is_artificial_event () const

bool	is_relay_log_event () const

bool	is_ignorable_event () const

bool	is_no_filter_event () const

bool	is_using_trans_cache () const

bool	is_using_stmt_cache () const

bool	is_using_immediate_logging () const

	Log_event (Log_event_header header, Log_event_footer footer)

virtual	~Log_event ()

void	register_temp_buf (char *buf, bool free_in_destructor=true)

void	free_temp_buf ()

virtual size_t	get_data_size ()

const char *	get_type_str () const
	Returns the human readable name of this event's type. More...

bool	is_mts_sequential_exec ()
	Is called from get_mts_execution_mode() to. More...

virtual uint8	get_mts_dbs (Mts_db_names arg, Rpl_filter rpl_filter)
	The method fills in pointers to event's database name c-strings to a supplied array. More...

bool	contains_partition_info (bool)

virtual uint8	mts_number_dbs ()

bool	is_mts_group_isolated ()

virtual bool	starts_group () const
	Events of a certain type can start or end a group of events treated transactionally wrt binlog. More...

virtual bool	ends_group () const

int	apply_event (Relay_log_info *rli)
	Apply the event to the database. More...

int	apply_gtid_event (Relay_log_info *rli)
	Apply the GTID event in curr_group_data to the database. More...

int	update_pos (Relay_log_info *rli)
	Update the relay log position. More...

enum_skip_reason	shall_skip (Relay_log_info *rli)
	Decide if the event shall be skipped, and the reason for skipping it. More...

virtual int	do_apply_event_worker (Slave_worker *w)

Public Attributes
bool	deferred

query_id_t	query_id

Public Attributes inherited from binary_log::User_var_event
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

Public Attributes inherited from Log_event
char *	temp_buf

bool	m_free_temp_buf_in_destructor

ulong	exec_time

uint32	server_id

ulong	rbr_exec_mode
	A storage to cache the global system variable's value. More...

enum_event_cache_type	event_cache_type
	Defines the type of the cache, if any, where the event will be stored before being flushed to disk. More...

enum_event_logging_type	event_logging_type
	Defines when information, i.e. More...

ha_checksum	crc
	Placeholder for event checksum while writing to binlog. More...

ulong	mts_group_idx
	Index in `rli->gaq` array to indicate a group that this event is purging. More...

binary_log::Log_event_header *	common_header
	The Log_event_header class contains the variable present in the common header. More...

binary_log::Log_event_footer *	common_footer
	The Log_event_footer class contains the variable present in the common footer. More...

Relay_log_info *	worker
	MTS: associating the event with either an assigned Worker or Coordinator. More...

ulonglong	future_event_relay_log_pos
	A copy of the main rli value stored into event to pass to MTS worker rli. More...

THD *	thd

db_worker_hash_entry *	mts_assigned_partitions [MAX_DBS_IN_EVENT_MTS]
	Partition info associate with event to deliver to MTS event applier. More...

Private Member Functions
int	do_apply_event (Relay_log_info const *rli) override
	Primitive to apply an event to the database. More...

int	do_update_pos (Relay_log_info *rli) override
	Advance relay log coordinates. More...

enum_skip_reason	do_shall_skip (Relay_log_info *rli) override
	Decide if this event shall be skipped or not and the reason for skipping it. More...

Additional Inherited Members
Public Types inherited from binary_log::User_var_event
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 binary_log::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 Types inherited from Log_event
enum	enum_skip_reason { EVENT_SKIP_NOT , EVENT_SKIP_IGNORE , EVENT_SKIP_COUNT }
	Enumeration of what kinds of skipping (and non-skipping) that can occur when the slave executes an event. More...

Static Public Member Functions inherited from Log_event
static void	init_show_field_list (mem_root_deque< Item * > *field_list)
	init_show_field_list() prepares the column names and types for the output of SHOW BINLOG EVENTS; it is used only by SHOW BINLOG EVENTS. More...

static void	operator delete (void *ptr, size_t)

static void *	operator new (size_t, void *ptr)

static void	operator delete (void , void )

static const char *	get_type_str (Log_event_type type)
	Returns the human readable name of the given event type. More...

static const char *	get_type_str (uint type)
	Get the name of an event type, or "Unknown" if out of range. More...

Static Public Attributes inherited from binary_log::Binary_log_event
static const int	LOG_EVENT_TYPES = (ENUM_END_EVENT - 1)

Protected Types inherited from Log_event
enum	enum_event_cache_type { EVENT_INVALID_CACHE = 0 , EVENT_STMT_CACHE , EVENT_TRANSACTIONAL_CACHE , EVENT_NO_CACHE , EVENT_CACHE_COUNT }

enum	enum_event_logging_type { EVENT_INVALID_LOGGING = 0 , EVENT_NORMAL_LOGGING , EVENT_IMMEDIATE_LOGGING , EVENT_CACHE_LOGGING_COUNT }

Protected Member Functions inherited from binary_log::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...

Protected Member Functions inherited from Log_event
uint32	write_header_to_memory (uchar *buf)
	Writes the common header of this event to the given memory buffer. More...

bool	write_header (Basic_ostream *ostream, size_t data_length)
	Writes the common-header of this event to the given output stream and updates the checksum. More...

bool	write_footer (Basic_ostream *ostream)

bool	need_checksum ()
	A decider of whether to trigger checksum computation or not. More...

enum_skip_reason	continue_group (Relay_log_info *rli)
	Helper function to ignore an event w.r.t. More...

Detailed Description

Every time a query uses the value of a user variable, a User_var_log_event is written before the Query_log_event, to set the user variable.

Constructor & Destructor Documentation

◆ User_var_log_event() [1/2]

User_var_log_event::User_var_log_event	(	THD *	thd_arg,
		const char *	name_arg,
		uint	name_len_arg,
		char *	val_arg,
		ulong	val_len_arg,
		Item_result	type_arg,
		uint	charset_number_arg,
		uchar	flags_arg,
		enum_event_cache_type	cache_type_arg,
		enum_event_logging_type	logging_type_arg
	)

inline

◆ User_var_log_event() [2/2]

User_var_log_event::User_var_log_event	(	const char *	buf,
		const Format_description_event *	description_event
	)

◆ ~User_var_log_event()

User_var_log_event::~User_var_log_event ( )

overridedefault

Member Function Documentation

◆ claim_memory_ownership()

void User_var_log_event::claim_memory_ownership ( bool claim )

overridevirtual

Allow thread to CLAIM or DISCLAIM the ownership of this object depends on the parameter value passed.

Parameters

claim True - claim ownership of the memory False - disclaim ownership of the memory

Reimplemented from Log_event.

◆ do_apply_event()

int User_var_log_event::do_apply_event ( Relay_log_info const * rli )

overrideprivatevirtual

Primitive to apply an event to the database.

This is where the change to the database is made.

Note: The primitive is protected instead of private, since there is a hierarchy of actions to be performed in some cases.

See also: Format_description_log_event::do_apply_event()

Parameters

rli	Pointer to relay log info structure

Return values

0	Event applied successfully
errno	Error code if event application failed

Reimplemented from Log_event.

◆ do_shall_skip()

Log_event::enum_skip_reason User_var_log_event::do_shall_skip ( Relay_log_info * rli )

overrideprivatevirtual

Decide if this event shall be skipped or not and the reason for skipping it.

The default implementation decide that the event shall be skipped if either:

the server id of the event is the same as the server id of the server and rli->replicate_same_server_id is true, or
if rli->slave_skip_counter is greater than zero.

See also: do_apply_event; do_update_pos

Return values

Log_event::EVENT_SKIP_NOT	The event shall not be skipped and should be applied.
Log_event::EVENT_SKIP_IGNORE	The event shall be skipped by just ignoring it, i.e., the slave skip counter shall not be changed. This happends if, for example, the originating server id of the event is the same as the server id of the slave.
Log_event::EVENT_SKIP_COUNT	The event shall be skipped because the slave skip counter was non-zero. The caller shall decrease the counter by one.

Reimplemented from Log_event.

◆ do_update_pos()

int User_var_log_event::do_update_pos ( Relay_log_info * rli )

overrideprivatevirtual

Advance relay log coordinates.

This function is called to advance the relay log coordinates to just after the event. It is essential that both the relay log coordinate and the group log position is updated correctly, since this function is used also for skipping events.

Normally, each implementation of do_update_pos() shall:

Update the event position to refer to the position just after the event.
Update the group log position to refer to the position just after the event if the event is last in a group

Parameters

rli	Pointer to relay log info structure

Return values

0	Coordinates changed successfully
errno	Error code if advancing failed (usually just 1). Observe that handler errors are returned by the do_apply_event() function, and not by this one.

Reimplemented from Log_event.

◆ is_deferred()

bool User_var_log_event::is_deferred ( )

inline

◆ is_sbr_logging_format()

bool User_var_log_event::is_sbr_logging_format ( ) const

inlineoverridevirtual

Return true if the event has to be logged using SBR for DMLs.

Reimplemented from Log_event.

◆ pack_info()

int User_var_log_event::pack_info ( Protocol * protocol )

overridevirtual

Stores a string representation of this event in the Protocol.

This is used by SHOW BINLOG EVENTS.

Return values

0	success
nonzero	error

Reimplemented from Log_event.

◆ set_deferred()

void User_var_log_event::set_deferred ( query_id_t qid )

inline

◆ write()

bool User_var_log_event::write ( Basic_ostream * ostream )

overridevirtual

Reimplemented from Log_event.

Member Data Documentation

◆ deferred

bool User_var_log_event::deferred

◆ query_id

query_id_t User_var_log_event::query_id

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

sql/log_event.h
sql/log_event.cc

Public Member Functions

Public Attributes

Private Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ User_var_log_event() [1/2]

◆ User_var_log_event() [2/2]

◆ ~User_var_log_event()

Member Function Documentation

◆ claim_memory_ownership()

◆ do_apply_event()

◆ do_shall_skip()

◆ do_update_pos()

◆ is_deferred()

◆ is_sbr_logging_format()

◆ pack_info()

◆ set_deferred()

◆ write()

Member Data Documentation

◆ deferred

◆ query_id