Logs random seed used by the next RAND(), and by PASSWORD() in 4.1.0. More...

#include <statement_events.h>

Inheritance diagram for mysql::binlog::event::Rand_event:

Public Types
enum	Rand_event_data { RAND_SEED1_OFFSET = 0 , RAND_SEED2_OFFSET = 8 }

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
	Rand_event (unsigned long long seed1_arg, unsigned long long seed2_arg)

	Rand_event (const char buf, const Format_description_event fde)
	Written every time a statement uses the RAND() function; precedes other events for the statement. More...

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
unsigned long long	seed1

unsigned long long	seed2

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

Logs random seed used by the next RAND(), and by PASSWORD() in 4.1.0.

4.1.1 does not need it (it's repeatable again) so this event needn't be written in 4.1.1 for PASSWORD() (but the fact that it is written is just a waste, it does not cause bugs).

The state of the random number generation consists of 128 bits, which are stored internally as two 64-bit numbers.

Binary Format

The Post-Header for this event type is empty. The Body has two components:

Body for Rand_event
Name	Format	Description
seed1	8 byte unsigned integer	64 bit random seed1.
seed2	8 byte unsigned integer	64 bit random seed2.

Member Enumeration Documentation

◆ Rand_event_data

enum mysql::binlog::event::Rand_event::Rand_event_data

Enumerator
RAND_SEED1_OFFSET
RAND_SEED2_OFFSET

Constructor & Destructor Documentation

◆ Rand_event() [1/2]

mysql::binlog::event::Rand_event::Rand_event	(	unsigned long long	seed1_arg,
		unsigned long long	seed2_arg
	)

inline

This will initialize the instance variables seed1 & seed2, and set the

type_code as RAND_EVENT in the header object in Binary_log_event

◆ Rand_event() [2/2]

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

Written every time a statement uses the RAND() function; precedes other events for the statement.

Indicates the seed values to use for generating a random number with RAND() 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 part is as follows:
+----------------------------------------------+
| value for first seed | value for second seed |
+----------------------------------------------+

Parameters

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

Member Data Documentation

◆ seed1

unsigned long long mysql::binlog::event::Rand_event::seed1

◆ seed2

unsigned long long mysql::binlog::event::Rand_event::seed2

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