binary_log::Binary_log_event Class Reference

This is the abstract base class for binary log events. More...

#include <binlog_event.h>

Inheritance diagram for binary_log::Binary_log_event:

Public Types
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
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...

Static Public Attributes
static const int	LOG_EVENT_TYPES = (ENUM_END_EVENT - 1)

Protected Member Functions
	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...

Private Attributes
Event_reader	m_reader
Log_event_header	m_header
Log_event_footer	m_footer

Detailed Description

This is the abstract base class for binary log events.

Binary Format

Any Binary_log_event saved on disk consists of the following four components.

• Common-Header
• Post-Header
• Body
• Footer

Common header has the same format and length in a given MySQL version. It is documented here.

The Body may be of different format and length even for different events of the same type. The binary formats of Post-Header and Body are documented separately in each subclass.

Footer is common to all the events in a given MySQL version. It is documented here.

• Some events, used for RBR use a special format for efficient representation of unsigned integers, called Packed Integer. A Packed Integer has the capacity of storing up to 8-byte integers, while small integers still can use 1, 3, or 4 bytes. The value of the first byte determines how to read the number, according to the following table:

Format of Packed Integer

First byte	Format
0-250	The first byte is the number (in the range 0-250), and no more bytes are used.
252	Two more bytes are used. The number is in the range 251-0xffff.
253	Three more bytes are used. The number is in the range 0xffff-0xffffff.
254	Eight more bytes are used. The number is in the range 0xffffff-0xffffffffffffffff.

• Strings are stored in various formats. The format of each string is documented separately.

Member Enumeration Documentation

enum_post_header_length

enum binary_log::Binary_log_event::enum_post_header_length

The lengths for the fixed data part of each event.

This is an enum that provides post-header lengths for all events.

Enumerator
QUERY_HEADER_MINIMAL_LEN
QUERY_HEADER_LEN
STOP_HEADER_LEN
START_V3_HEADER_LEN
ROTATE_HEADER_LEN
INTVAR_HEADER_LEN
APPEND_BLOCK_HEADER_LEN
DELETE_FILE_HEADER_LEN
RAND_HEADER_LEN
USER_VAR_HEADER_LEN
FORMAT_DESCRIPTION_HEADER_LEN
XID_HEADER_LEN
BEGIN_LOAD_QUERY_HEADER_LEN
ROWS_HEADER_LEN_V1
TABLE_MAP_HEADER_LEN
EXECUTE_LOAD_QUERY_EXTRA_HEADER_LEN
EXECUTE_LOAD_QUERY_HEADER_LEN
INCIDENT_HEADER_LEN
HEARTBEAT_HEADER_LEN
IGNORABLE_HEADER_LEN
ROWS_HEADER_LEN_V2
TRANSACTION_CONTEXT_HEADER_LEN
VIEW_CHANGE_HEADER_LEN
XA_PREPARE_HEADER_LEN
TRANSACTION_PAYLOAD_HEADER_LEN

Constructor & Destructor Documentation

Binary_log_event() [1/4]

binary_log::Binary_log_event::Binary_log_event ( Log_event_type  type_code )

inlineexplicitprotected

This constructor is used to initialize the type_code of header object m_header.

We set the type code to ENUM_END_EVENT so that the decoder asserts if event type has not been modified by the sub classes

Binary_log_event() [2/4]

binary_log::Binary_log_event::Binary_log_event ( const char **  buf, const Format_description_event *  fde  )

protected

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.

It will also advance the Event_reader cursor after decoding the header (it is done through the constructor of Log_event_header) and will be pointing to the start of event data.

Parameters

buf	Contains the serialized event.
fde	An FDE event used to get checksum information of non FDE events.

~Binary_log_event()

binary_log::Binary_log_event::~Binary_log_event ( )

pure virtualdefault

Binary_log_event() [3/4]

binary_log::Binary_log_event::Binary_log_event ( const Binary_log_event &  )

default

Binary_log_event() [4/4]

binary_log::Binary_log_event::Binary_log_event ( Binary_log_event &&  )

default

Member Function Documentation

footer() [1/2]

Log_event_footer * binary_log::Binary_log_event::footer ( )

inline

Return a non-const pointer to the footer of the log event.

footer() [2/2]

const Log_event_footer * binary_log::Binary_log_event::footer ( ) const

inline

Return a const pointer to the footer of the log event.

get_event_type()

enum Log_event_type binary_log::Binary_log_event::get_event_type ( ) const

inline

Helper method.

header() [1/2]

Log_event_header * binary_log::Binary_log_event::header ( )

inline

Return a non-const pointer to the header of the log event.

header() [2/2]

const Log_event_header * binary_log::Binary_log_event::header ( ) const

inline

Return a const pointer to the header of the log event.

operator=() [1/2]

Binary_log_event & binary_log::Binary_log_event::operator= ( Binary_log_event &&  )

default

operator=() [2/2]

Binary_log_event & binary_log::Binary_log_event::operator= ( const Binary_log_event &  )

default

reader()

Event_reader & binary_log::Binary_log_event::reader ( )

inline

Returns a reference to the event Event_reader object.

Member Data Documentation

LOG_EVENT_TYPES

const int binary_log::Binary_log_event::LOG_EVENT_TYPES = (ENUM_END_EVENT - 1)

static

m_footer

Log_event_footer binary_log::Binary_log_event::m_footer

private

m_header

Log_event_header binary_log::Binary_log_event::m_header

private

m_reader

Event_reader binary_log::Binary_log_event::m_reader

private

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

• libbinlogevents/include/binlog_event.h
• libbinlogevents/src/binlog_event.cpp