mysql::csa::Fetchable_transaction Class Reference

Opaque for transaction, that is able to fetch itself in parts from the storage on demand. More...

#include <fetchable_transaction.h>

Public Types
using	Return_status = mysql::utils::Return_status

Public Member Functions
	Fetchable_transaction ()
	Fetch function is supplied by a specific storage implementation. More...
	Fetchable_transaction (Event_set_fetchable_list &&fetch_object)
	Fetchable_transaction (const Fetchable_transaction &)=delete
	Fetchable_transaction (Fetchable_transaction &&)=delete
virtual	~Fetchable_transaction ()
	Destructor. More...
bool	wait_next ()
	Fetches consecutive events from the storage, until done or error occurs. More...
std::optional< Managed_event >	fetch_next ()
bool	is_fetching_error () const
	Returs true when fetching failed. More...
bool	is_fetching_done () const
	Checks current status of the object. More...
bool	is_truncated () const
	Checks whether fetching stopped because the metadata stream was truncated. More...
std::size_t	get_max_event_length () const
	Returns the maximum event length published for this transaction. More...
void	reset_fetching (bool all)
	Reset the status of the Featchable job allowing it to be re-read from the storage. More...
std::string	get_fetch_error_msg () const
	Accesses fetch error message. More...
bool	is_trx () const
	Returns information on whether this is actual transaction (transaction starting with a GTID) More...
void	set_success ()
	Marks that transaction committed succesfully, success callback. More...
Format_description_log_event *	get_fde ()
	Obtains non-owning pointer to current FDE. More...
void	set_fetching_done ()
	Mark that fetching is successfully done, even if transaction was not fully read. More...
void	append_batch (Event_set_fetchable_ptr batch)
	Appends a new fetchable batch for this transaction. More...
void	set_fetching_complete ()
	Seals transaction metadata stream. No more batches will be appended. More...
void	update_max_event_length (std::size_t event_length)
	Updates the maximum event length published for this transaction. More...
void	set_fetching_truncated ()
	Marks transaction metadata stream as truncated. More...

Private Member Functions
Event_set_fetchable *	wait_for_current_batch ()
	Waits until a current batch becomes available or fetching reaches a terminal state. More...
bool	advance_finished_batch_unsafe (Event_set_fetchable *event_batch)
	Advances to the next batch if the current one has finished. More...
std::optional< Event_set_fetchable * >	get_current_event_batch_unsafe ()
	Iterates over event sets, picking a correct batch. More...

Private Attributes
std::string	m_error_message
	Detailed error message if error appears. More...
Return_status	m_status
	Internal status of event. More...
bool	m_is_done {false}
	True when the consumer-side fetch stream reached a terminal state. More...
bool	m_is_complete {false}
	True when reader has finished appending batches. More...
std::atomic< std::size_t >	m_max_event_length {0}
	Maximum event length published for this transaction. More...
std::atomic< bool >	m_is_truncated {false}
	True when reader marked metadata stream as truncated. More...
std::mutex	m_mutex
	Guard for concurrent producer (reader) and consumer (worker). More...
std::condition_variable	m_cv
	Notification for appended batches / terminal state updates. More...
Event_set_fetchable_list	m_event_set_batches
	Object used to fetch transaction events from the storage. More...
Event_set_fetchable_list::iterator	m_current_batch_it
	Currently processed event batch iterator. More...

Detailed Description

Opaque for transaction, that is able to fetch itself in parts from the storage on demand.

Function to fetch an event is supplied by the specific storage implementation.

Member Typedef Documentation

Return_status

using mysql::csa::Fetchable_transaction::Return_status = mysql::utils::Return_status

Constructor & Destructor Documentation

Fetchable_transaction() [1/4]

mysql::csa::Fetchable_transaction::Fetchable_transaction

(

)

Fetch function is supplied by a specific storage implementation.

Fetchable_transaction() [2/4]

mysql::csa::Fetchable_transaction::Fetchable_transaction

(

Event_set_fetchable_list &&

fetch_object

)

Fetchable_transaction() [3/4]

mysql::csa::Fetchable_transaction::Fetchable_transaction ( const Fetchable_transaction &  )

delete

Fetchable_transaction() [4/4]

mysql::csa::Fetchable_transaction::Fetchable_transaction ( Fetchable_transaction &&  )

delete

~Fetchable_transaction()

mysql::csa::Fetchable_transaction::~Fetchable_transaction ( )

virtual

Destructor.

Member Function Documentation

advance_finished_batch_unsafe()

bool mysql::csa::Fetchable_transaction::advance_finished_batch_unsafe ( Event_set_fetchable *  event_batch )

private

Advances to the next batch if the current one has finished.

Parameters

event_batch

Current batch being processed.

Return values

true	The whole transaction finished.
false	There may still be more events or batches to fetch.

append_batch()

void mysql::csa::Fetchable_transaction::append_batch

(

Event_set_fetchable_ptr

batch

)

Appends a new fetchable batch for this transaction.

fetch_next()

std::optional< Managed_event > mysql::csa::Fetchable_transaction::fetch_next

(

)

get_current_event_batch_unsafe()

std::optional< Event_set_fetchable * > mysql::csa::Fetchable_transaction::get_current_event_batch_unsafe ( )

private

Iterates over event sets, picking a correct batch.

get_fde()

Format_description_log_event * mysql::csa::Fetchable_transaction::get_fde

(

)

Obtains non-owning pointer to current FDE.

Returns

Non-owning pointer to current FDE

get_fetch_error_msg()

std::string mysql::csa::Fetchable_transaction::get_fetch_error_msg

(

)

const

Accesses fetch error message.

Returns

Fetch error information

get_max_event_length()

std::size_t mysql::csa::Fetchable_transaction::get_max_event_length

(

)

const

Returns the maximum event length published for this transaction.

is_fetching_done()

bool mysql::csa::Fetchable_transaction::is_fetching_done

(

)

const

Checks current status of the object.

Returns

True when fetching is completed, false otherwise

is_fetching_error()

bool mysql::csa::Fetchable_transaction::is_fetching_error

(

)

const

Returs true when fetching failed.

Returns

True when fetching failed, false otherwise

is_truncated()

bool mysql::csa::Fetchable_transaction::is_truncated

(

)

const

Checks whether fetching stopped because the metadata stream was truncated.

Returns

True when fetching stopped on truncation, false otherwise

is_trx()

bool mysql::csa::Fetchable_transaction::is_trx

(

)

const

Returns information on whether this is actual transaction (transaction starting with a GTID)

reset_fetching()

void mysql::csa::Fetchable_transaction::reset_fetching

(

bool

all

)

Reset the status of the Featchable job allowing it to be re-read from the storage.

Parameters

all	When true, internal object states must be reset

set_fetching_complete()

void mysql::csa::Fetchable_transaction::set_fetching_complete

(

)

Seals transaction metadata stream. No more batches will be appended.

set_fetching_done()

void mysql::csa::Fetchable_transaction::set_fetching_done

(

)

Mark that fetching is successfully done, even if transaction was not fully read.

set_fetching_truncated()

void mysql::csa::Fetchable_transaction::set_fetching_truncated

(

)

Marks transaction metadata stream as truncated.

set_success()

void mysql::csa::Fetchable_transaction::set_success

(

)

Marks that transaction committed succesfully, success callback.

update_max_event_length()

void mysql::csa::Fetchable_transaction::update_max_event_length

(

std::size_t

event_length

)

Updates the maximum event length published for this transaction.

wait_for_current_batch()

Event_set_fetchable * mysql::csa::Fetchable_transaction::wait_for_current_batch ( )

private

Waits until a current batch becomes available or fetching reaches a terminal state.

Returns

Current batch pointer or nullptr in terminal state.

wait_next()

bool mysql::csa::Fetchable_transaction::wait_next

(

)

Fetches consecutive events from the storage, until done or error occurs.

Returns

Managed event object in case it was successfully fetched from the storage, empty object in case stream is done or error occurred

Member Data Documentation

m_current_batch_it

Event_set_fetchable_list::iterator mysql::csa::Fetchable_transaction::m_current_batch_it

private

Currently processed event batch iterator.

m_cv

std::condition_variable mysql::csa::Fetchable_transaction::m_cv

private

Notification for appended batches / terminal state updates.

m_error_message

std::string mysql::csa::Fetchable_transaction::m_error_message

private

Detailed error message if error appears.

m_event_set_batches

Event_set_fetchable_list mysql::csa::Fetchable_transaction::m_event_set_batches

private

Object used to fetch transaction events from the storage.

m_is_complete

bool mysql::csa::Fetchable_transaction::m_is_complete {false}

private

True when reader has finished appending batches.

m_is_done

bool mysql::csa::Fetchable_transaction::m_is_done {false}

private

True when the consumer-side fetch stream reached a terminal state.

m_is_truncated

std::atomic<bool> mysql::csa::Fetchable_transaction::m_is_truncated {false}

private

True when reader marked metadata stream as truncated.

m_max_event_length

std::atomic<std::size_t> mysql::csa::Fetchable_transaction::m_max_event_length {0}

private

Maximum event length published for this transaction.

m_mutex

std::mutex mysql::csa::Fetchable_transaction::m_mutex

mutableprivate

Guard for concurrent producer (reader) and consumer (worker).

m_status

Return_status mysql::csa::Fetchable_transaction::m_status

private

Internal status of event.

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

• sql/changestreams/apply/jobs/fetchable_transaction.h
• sql/changestreams/apply/jobs/fetchable_transaction.cpp