qb::io::async::input< _Derived > Class Template Reference

CRTP base class for managing asynchronous input operations with protocol processing. More...

#include <io.h>

Inheritance diagram for qb::io::async::input< _Derived >:

Collaboration diagram for qb::io::async::input< _Derived >:

Public Types
using	base_io_t = input<_Derived>
	Base I/O type alias for CRTP.

Public Member Functions
	input ()=default
	Default constructor.
	input (IProtocol *protocol) noexcept
	Constructor with an initial protocol instance.
	input (input const &)=delete
	Deleted copy constructor to prevent unintended copying of I/O state and resources.
	~input () noexcept
	Destructor.
template<typename _Protocol, typename... _Args>
_Protocol *	switch_protocol (_Args &&...args)
	Switches to a new protocol for processing input, taking ownership of the new protocol.
void	clear_protocols ()
	Clears all owned protocol instances.
IProtocol *	protocol ()
	Gets a pointer to the current active protocol instance.
void	start () noexcept
	Starts asynchronous input operations.
void	ready_to_read () noexcept
	Ensures the I/O watcher is listening for read events (EV_READ).
void	disconnect (int reason=1)
	Initiates a graceful disconnection of the input component.

Static Public Attributes
static constexpr const bool	has_server = false
	Indicates this component is not inherently a server (e.g., an acceptor).

Protected Member Functions
void	dispose ()
	Disposes of resources and finalizes disconnection for the input component.
Protected Member Functions inherited from qb::io::async::base< input< _Derived >, event::io >
	base ()
	Constructor that registers the event watcher with the current listener.
	~base ()
	Destructor that unregisters the event watcher.

Additional Inherited Members
Protected Attributes inherited from qb::io::async::base< input< _Derived >, event::io >
event::io &	_async_event
	Reference to the registered libev-based event watcher.

Detailed Description

template<typename _Derived>
class qb::io::async::input< _Derived >

CRTP base class for managing asynchronous input operations with protocol processing.

This template class provides functionality for asynchronous input. It uses an event::io watcher to monitor a file descriptor for read readiness. Data read from the transport (provided by _Derived::transport()) is processed using an AProtocol instance.

Template Parameters

_Derived

The derived class type (CRTP pattern) that provides the transport (e.g., a socket wrapper) and handles protocol messages and I/O events.

Constructor & Destructor Documentation

input() [1/2]

template<typename _Derived>

qb::io::async::input< _Derived >::input ( )

default

Default constructor.

Initializes the input component without a specific protocol. A protocol should be set using switch_protocol() before starting operations that require one.

input() [2/2]

template<typename _Derived>

qb::io::async::input< _Derived >::input ( IProtocol * protocol )

inlinenoexcept

Constructor with an initial protocol instance.

Parameters

protocol

Pointer to an existing protocol instance. This input component will use it and take ownership by adding it to its internal list of protocols for cleanup.

Note

If the protocol is managed externally, consider setting it via set_protocol_no_ownership (if such a method existed) or ensure clear_protocols is not called if it would delete an externally managed protocol. Currently, this constructor implies ownership.

~input()

template<typename _Derived>

qb::io::async::input< _Derived >::~input ( )

inlinenoexcept

Destructor.

Calls clear_protocols() to clean up all protocol instances owned by this component. The base class destructor will handle unregistering the event::io watcher.

Member Function Documentation

switch_protocol()

template<typename _Derived>

template<typename _Protocol, typename... _Args>

_Protocol * qb::io::async::input< _Derived >::switch_protocol ( _Args &&... args )

inline

Switches to a new protocol for processing input, taking ownership of the new protocol.

Template Parameters

_Protocol	The concrete AProtocol type to instantiate.
_Args	Argument types for the _Protocol constructor.

Parameters

args	Arguments to forward to the _Protocol constructor.

Returns

Pointer to the newly created and activated protocol instance if successful (protocol's ok() returns true), otherwise nullptr (and the created protocol instance is deleted).

The new protocol instance is added to an internal list and will be cleaned up by this input component's destructor. The current active protocol is set to this new instance. Previous protocols in the list are not deleted by this call.

clear_protocols()

template<typename _Derived>

void qb::io::async::input< _Derived >::clear_protocols ( )

inline

Clears all owned protocol instances.

Deletes all protocol instances stored in the internal _protocol_list and resets the current _protocol pointer to nullptr. This is called automatically by the destructor.

protocol()

template<typename _Derived>

IProtocol * qb::io::async::input< _Derived >::protocol ( )

inline

Gets a pointer to the current active protocol instance.

Returns

Pointer to the IProtocol currently in use for message parsing, or nullptr if no protocol is set.

start()

template<typename _Derived>

void qb::io::async::input< _Derived >::start ( )

inlinenoexcept

Starts asynchronous input operations.

Sets the underlying transport (obtained via _Derived::transport()) to non-blocking mode and starts the event::io watcher to listen for read events (EV_READ). Resets any previous disconnection reason (_reason = 0).

ready_to_read()

template<typename _Derived>

void qb::io::async::input< _Derived >::ready_to_read ( )

inlinenoexcept

Ensures the I/O watcher is listening for read events (EV_READ).

If the internal event::io watcher (from the base class) is not currently set to listen for EV_READ, this method reconfigures and restarts it to include EV_READ in its watched events. This is useful if read operations were temporarily paused.

disconnect()

template<typename _Derived>

void qb::io::async::input< _Derived >::disconnect ( int reason = 1 )

inline

Initiates a graceful disconnection of the input component.

Parameters

reason

An optional integer code indicating the reason for disconnection (e.g., user action, protocol error). This value will be passed in the event::disconnected if that event is handled by the derived class.

Sets an internal flag (_reason) with the provided reason and feeds an EV_UNDEF event to the listener. This typically causes the on(event::io&) handler to enter its error path during the next event loop cycle, leading to the invocation of the dispose() method for cleanup.

dispose()

template<typename _Derived>

void qb::io::async::input< _Derived >::dispose ( )

inlineprotected

Disposes of resources and finalizes disconnection for the input component.

This method is called internally when an I/O error occurs or when disconnect() is explicitly initiated. It ensures cleanup happens only once by checking the _is_disposed flag. If _Derived implements on(event::disconnected&), this method is called with the stored _reason. If _Derived::has_server is true (typically for server-side sessions), it notifies the server of the disconnection. Otherwise, if _Derived implements on(event::dispose&), that method is called as a final cleanup hook. The base class (async::base) destructor will handle unregistering the event::io watcher.