Binlog_event_writer Class Reference

Auxiliary class to copy serialized events to the binary log and correct some of the fields that are not known until just before writing the event. More...

Inheritance diagram for Binlog_event_writer:

Public Member Functions
	Binlog_event_writer (MYSQL_BIN_LOG::Binlog_ofile *binlog_file)
	Constructs a new Binlog_event_writer. More...
void	update_header ()
bool	write (const unsigned char *buffer, my_off_t length) override
	Write some bytes into the output stream. More...
bool	is_checksum_enabled ()
	Returns true if per event checksum is enabled. More...
Public Member Functions inherited from Basic_ostream
virtual	~Basic_ostream ()=default

Private Attributes
MYSQL_BIN_LOG::Binlog_ofile *	m_binlog_file
bool	have_checksum
ha_checksum	initial_checksum
ha_checksum	checksum
uint32	end_log_pos
uchar	header [LOG_EVENT_HEADER_LEN]
my_off_t	header_len = 0
uint32	event_len = 0

Detailed Description

Auxiliary class to copy serialized events to the binary log and correct some of the fields that are not known until just before writing the event.

This class allows feeding events in parts, so it is practical to use in do_write_cache() which reads events from an IO_CACHE where events may span multiple cache pages.

The following fields are fixed before writing the event:

• end_log_pos is set
• the checksum is computed if checksums are enabled
• the length is incremented by the checksum size if checksums are enabled

Constructor & Destructor Documentation

Binlog_event_writer()

Binlog_event_writer::Binlog_event_writer ( MYSQL_BIN_LOG::Binlog_ofile *  binlog_file )

inline

Constructs a new Binlog_event_writer.

Should be called once before starting to flush the transaction or statement cache to the binlog.

Parameters

binlog_file

to write to.

Member Function Documentation

is_checksum_enabled()

bool Binlog_event_writer::is_checksum_enabled ( )

inline

Returns true if per event checksum is enabled.

update_header()

void Binlog_event_writer::update_header ( )

inline

write()

bool Binlog_event_writer::write ( const unsigned char *  buffer, my_off_t  length  )

inlineoverridevirtual

Write some bytes into the output stream.

When all data is written into the stream successfully, then it return false. Otherwise, true is returned. It will never returns false when partial data is written into the stream.

Parameters

[in]	buffer	Data to be written
[in]	length	Length of the data

Return values

false	Success.
true	Error.

Implements Basic_ostream.

Member Data Documentation

checksum

ha_checksum Binlog_event_writer::checksum

private

end_log_pos

uint32 Binlog_event_writer::end_log_pos

private

event_len

uint32 Binlog_event_writer::event_len = 0

private

have_checksum

bool Binlog_event_writer::have_checksum

private

header

uchar Binlog_event_writer::header[LOG_EVENT_HEADER_LEN]

private

header_len

my_off_t Binlog_event_writer::header_len = 0

private

initial_checksum

ha_checksum Binlog_event_writer::initial_checksum

private

m_binlog_file

MYSQL_BIN_LOG::Binlog_ofile* Binlog_event_writer::m_binlog_file

private

---

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

• sql/binlog.cc