Event_cataloger Class Reference

#include <event_cataloger.h>

Inheritance diagram for Event_cataloger:

Public Member Functions
	Event_cataloger ()
int	handle_event (Pipeline_event *ev, Continuation *cont) override
	Handling of an event as defined in the handler implementation. More...
int	handle_action (Pipeline_action *action) override
	Handling of an action as defined in the handler implementation. More...
int	initialize () override
	Initialization as defined in the handler implementation. More...
int	terminate () override
	Terminate the execution as defined in the handler implementation. More...
bool	is_unique () override
	This method identifies the handler as being unique. More...
int	get_role () override
	This method returns the handler role. More...
Public Member Functions inherited from Event_handler
	Event_handler ()
virtual	~Event_handler ()=default
void	plug_next_handler (Event_handler *next_handler)
	Plug an handler to be the next in line for execution. More...
void	append (Event_handler *last_handler)
	Append an handler to be the last in line for execution. More...
int	terminate_pipeline ()
	Shutdown and delete all handlers in the pipeline. More...

Additional Inherited Members
Static Public Member Functions inherited from Event_handler
static void	append_handler (Event_handler **pipeline, Event_handler *event_handler)
	Append an handler to a given pipeline. More...
static void	get_handler_by_role (Event_handler *pipeline, int role, Event_handler **event_handler)
	Returns an handler that plays the given role. More...
Protected Member Functions inherited from Event_handler
int	next (Pipeline_event *event, Continuation *continuation)
	Pass the event to the next handler in line. More...
int	next (Pipeline_action *action)
	Pass the action to the next handler in line. More...

Constructor & Destructor Documentation

Event_cataloger()

Event_cataloger::Event_cataloger ( )

default

Member Function Documentation

get_role()

int Event_cataloger::get_role ( )

overridevirtual

This method returns the handler role.

Handlers can have different roles according to the tasks they represent. Is based on this role that certain components can extract and interact with pipeline handlers. This means that if a role is given to a singleton handler, no one else can have that role.

Returns

the handler role

Implements Event_handler.

handle_action()

int Event_cataloger::handle_action ( Pipeline_action *  action )

overridevirtual

Handling of an action as defined in the handler implementation.

As the handler can be included in a pipeline, somewhere in the method, the handler.next(action) method shall be invoked to allow the passing of the action to the next handler.

Note

Actions should not be treated asynchronously and as so, Continuations are not used here. Errors are returned directly or passed by in the action if it includes support for such

Parameters

[in]

action

the pipeline event to be handled

Implements Event_handler.

handle_event()

int Event_cataloger::handle_event ( Pipeline_event *  event, Continuation *  continuation  )

overridevirtual

Handling of an event as defined in the handler implementation.

As the handler can be included in a pipeline, somewhere in the method, the handler.next(event,continuation) method shall be invoked to allow the passing of the event to the next handler.

Also, if an error occurs, the continuation object shall be used to propagate such error. This class can also be used to know/report when the transaction to whom the event belongs was discarded.

Parameters

[in]	event	the pipeline event to be handled
[in,out]	continuation	termination notification object.

Implements Event_handler.

initialize()

int Event_cataloger::initialize ( )

overridevirtual

Initialization as defined in the handler implementation.

Note

It's up to the developer to decide its own initialization strategy, but the suggested approach is to initialize basic structures here and then depend on Action packets to configure and start existing handler routines.

Implements Event_handler.

is_unique()

bool Event_cataloger::is_unique ( )

overridevirtual

This method identifies the handler as being unique.

An handler that is defined as unique is an handler that cannot be used more than once in a pipeline. Such tasks as certification and event application can only be done once. Unique handlers are also the only that, by being one of a kind, can be extracted during the pipeline life allowing dynamic changes to them.

Returns

if the handler is the a unique handler

Return values

true	is a unique handler
false	is a repeatable handler

Implements Event_handler.

terminate()

int Event_cataloger::terminate ( )

overridevirtual

Terminate the execution as defined in the handler implementation.

Implements Event_handler.

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

• plugin/group_replication/include/handlers/event_cataloger.h
• plugin/group_replication/src/handlers/event_cataloger.cc