Binlog_event_data_istream Class Reference

Binlog_event_data_istream fetches byte data from Basic_istream and divides them into event_data chunk according to the format. More...

#include <binlog_reader.h>

Public Member Functions
	Binlog_event_data_istream (Binlog_read_error *error, Basic_istream *istream, unsigned int max_event_size)
	Binlog_event_data_istream ()=delete
	Binlog_event_data_istream (const Binlog_event_data_istream &)=delete
Binlog_event_data_istream &	operator= (const Binlog_event_data_istream &)=delete
virtual	~Binlog_event_data_istream ()=default
template<class ALLOCATOR >
bool	read_event_data (unsigned char **data, unsigned int *length, ALLOCATOR *allocator, bool verify_checksum, mysql::binlog::event::enum_binlog_checksum_alg checksum_alg)
	Read an event data from the stream and verify its checksum if verify_checksum is true. More...

Protected Member Functions
virtual bool	read_event_header ()
	Read the event header from the Basic_istream. More...
bool	check_event_header ()
	Check if it is a valid event header. More...
template<Binlog_read_error::Error_type ERROR_TYPE>
bool	read_fixed_length (unsigned char *data, unsigned int length)
	Read fixed length of data from Basic_istream. More...

Protected Attributes
unsigned char	m_header [LOG_EVENT_MINIMAL_HEADER_LEN]
Binlog_read_error *	m_error
	It is convenient for caller to share a Binlog_read_error object between streams. More...

Private Member Functions
bool	fill_event_data (unsigned char *event_data, bool verify_checksum, mysql::binlog::event::enum_binlog_checksum_alg checksum_alg)
	Fill the event data into the given buffer and verify checksum if 'verify_checksum' is true. More...

Private Attributes
Basic_istream *	m_istream = nullptr
unsigned int	m_max_event_size
unsigned int	m_event_length = 0

Detailed Description

Binlog_event_data_istream fetches byte data from Basic_istream and divides them into event_data chunk according to the format.

Event_data is a serialized event object. It is a chunk of data in buffer.

Constructor & Destructor Documentation

Binlog_event_data_istream() [1/3]

Binlog_event_data_istream::Binlog_event_data_istream	(	Binlog_read_error *	error,
		Basic_istream *	istream,
		unsigned int	max_event_size
	)

Binlog_event_data_istream() [2/3]

Binlog_event_data_istream::Binlog_event_data_istream ( )

delete

Binlog_event_data_istream() [3/3]

Binlog_event_data_istream::Binlog_event_data_istream ( const Binlog_event_data_istream &  )

delete

~Binlog_event_data_istream()

virtual Binlog_event_data_istream::~Binlog_event_data_istream ( )

virtualdefault

Member Function Documentation

check_event_header()

bool Binlog_event_data_istream::check_event_header ( )

protected

Check if it is a valid event header.

Return values

false	Success
true	Error

fill_event_data()

bool Binlog_event_data_istream::fill_event_data ( unsigned char *  event_data, bool  verify_checksum, mysql::binlog::event::enum_binlog_checksum_alg  checksum_alg  )

private

Fill the event data into the given buffer and verify checksum if 'verify_checksum' is true.

Parameters

[in]	event_data	The buffer where the event data will be stored.
[in]	verify_checksum	Verify the event data's checksum if it is true.
[in]	checksum_alg	Checksum algorithm for verifying the event data. It is used only when verify_checksum is true.

Return values

false	Success
true	Error

operator=()

Binlog_event_data_istream & Binlog_event_data_istream::operator= ( const Binlog_event_data_istream &  )

delete

read_event_data()

template<class ALLOCATOR >

bool Binlog_event_data_istream::read_event_data ( unsigned char **  data, unsigned int *  length, ALLOCATOR *  allocator, bool  verify_checksum, mysql::binlog::event::enum_binlog_checksum_alg  checksum_alg  )

inline

Read an event data from the stream and verify its checksum if verify_checksum is true.

Parameters

[out]	data	The pointer of the event data
[out]	length	The length of the event data
[in]	allocator	It is used to allocate memory for the event data.
[in]	verify_checksum	Verify the event data's checksum if it is true.
[in]	checksum_alg	Checksum algorithm for verifying the event data. It is used only when verify_checksum is true.

Return values

false	Success
true	Error

read_event_header()

bool Binlog_event_data_istream::read_event_header ( )

protectedvirtual

Read the event header from the Basic_istream.

Return values

false	Success
true	Error

read_fixed_length()

template<Binlog_read_error::Error_type ERROR_TYPE>

bool Binlog_event_data_istream::read_fixed_length ( unsigned char *  data, unsigned int  length  )

inlineprotected

Read fixed length of data from Basic_istream.

It sets error to

• Binlog_read_error::SYTEM_IO if Basic_istream returns error.
• Binlog_read_error::TRUNC_EVENT if less than length is read.
• ERROR_TYPE if zero byte is read. ERROR_TYPE is either TRUNC_EVENT or READ_EOF.

Parameters

[in]	data	The buffer where the data stored.
[in]	length	Bytes of the data to be read.

Return values

false	Success
true	Error

Member Data Documentation

m_error

Binlog_read_error* Binlog_event_data_istream::m_error

protected

It is convenient for caller to share a Binlog_read_error object between streams.

So Binlog_read_error pointer is defined here. It should be initialized in constructor by caller.

m_event_length

unsigned int Binlog_event_data_istream::m_event_length = 0

private

m_header

unsigned char Binlog_event_data_istream::m_header[LOG_EVENT_MINIMAL_HEADER_LEN]

protected

m_istream

Basic_istream* Binlog_event_data_istream::m_istream = nullptr

private

m_max_event_size

unsigned int Binlog_event_data_istream::m_max_event_size

private

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

• sql/binlog_reader.h
• sql/binlog_reader.cc