dfx::Core::Channel Class Reference

Abstract message channel connecting exactly one output port to one input port. More...

#include <dfx-core/channels/Channel.hpp>

Inheritance diagram for dfx::Core::Channel:

Collaboration diagram for dfx::Core::Channel:

Public Types
using	Id = uint32_t
	Identifier type (unique within a graph instance, by convention).

Public Member Functions
	Channel (Id id, InputPort &inputPort, OutputPort &outputPort)
	Construct a channel linking one input port to one output port.
	DISABLE_COPY_AND_MOVE (Channel)
	Channel is not copiable nor movable.
virtual	~Channel ()=default
	Virtual destructor.
Id	id () const noexcept
	Get the channel id.
template<DerivedFromChannel T>
bool	is () const noexcept
	Check whether this channel is of a given derived type.
template<DerivedFromChannel T>
T &	as () noexcept
	Cast this channel to a derived type (unchecked).
template<DerivedFromChannel T>
T const &	as () const noexcept
	Cast this channel to a derived type (unchecked).
InputPort &	inputPort () const noexcept
	Destination (consumer) endpoint of this channel.
OutputPort &	outputPort () const noexcept
	Source (producer) endpoint of this channel.
void	setDeliveryHook (Hooks::Delivery *hook)
	Set the optional delivery hook for this channel.
Queue-like interface
virtual bool	pushMessage (MessagePtr msg)=0
	Push a message into the channel from the producer side.
virtual bool	hasPendingMessage () const =0
	Whether at least one message is pending in this channel.
virtual std::size_t	pendingMessageCount () const =0
	Number of messages currently pending in this channel.
virtual std::optional< MessagePtr >	pop ()=0
	Pop the next message from the channel.

Protected Attributes
InputPort &	_inputPort
	Destination port (consumer).
OutputPort &	_outputPort
	Source port (producer).
Hooks::Delivery *	_deliveryHook = nullptr
	Optional delivery hook (non-owning).

Detailed Description

Abstract message channel connecting exactly one output port to one input port.

A channel is a directed edge in the graph:

• Source endpoint: outputPort()
• Destination endpoint: inputPort()

Ownership and lifetime

The channel stores references to both endpoints. It therefore assumes both ports outlive the channel (typically: the graph owns nodes/ports and channels together).

The class is explicitly non-copyable and non-movable.

Delivery hook

A channel can optionally be configured with a dfx::Hooks::Delivery hook via setDeliveryHook. The base class only stores the pointer; it is the job of concrete implementations to invoke it at the appropriate points (enqueue/dequeue, pre/post delivery, etc.).

Note

pushMessage returns a boolean to allow implementations to reject messages (e.g. bounded queues, backpressure, shutdown).

Member Typedef Documentation

Id

using dfx::Core::Channel::Id = uint32_t

Identifier type (unique within a graph instance, by convention).

Constructor & Destructor Documentation

Channel()

dfx::Core::Channel::Channel	(	Id	id,
		InputPort &	inputPort,
		OutputPort &	outputPort )

Construct a channel linking one input port to one output port.

Parameters

id	Channel id.
inputPort	Destination port (consumer).
outputPort	Source port (producer).

~Channel()

virtual dfx::Core::Channel::~Channel ( )

virtualdefault

Virtual destructor.

Member Function Documentation

as() [1/2]

template<DerivedFromChannel T>

T const & dfx::Core::Channel::as ( ) const

inlinenoexcept

Cast this channel to a derived type (unchecked).

Template Parameters

T	A type derived from Channel.

Warning

This uses static_cast. Only call after checking with is.

as() [2/2]

template<DerivedFromChannel T>

T & dfx::Core::Channel::as ( )

inlinenoexcept

Cast this channel to a derived type (unchecked).

Template Parameters

T	A type derived from Channel.

Warning

This uses static_cast. Only call after checking with is.

DISABLE_COPY_AND_MOVE()

dfx::Core::Channel::DISABLE_COPY_AND_MOVE

(

Channel

)

Channel is not copiable nor movable.

hasPendingMessage()

virtual bool dfx::Core::Channel::hasPendingMessage ( ) const

pure virtual

Whether at least one message is pending in this channel.

Implemented in dfx::Core::SPSCChannel.

id()

Id dfx::Core::Channel::id ( ) const

inlinenoexcept

Get the channel id.

inputPort()

InputPort & dfx::Core::Channel::inputPort ( ) const

inlinenoexcept

Destination (consumer) endpoint of this channel.

is()

template<DerivedFromChannel T>

bool dfx::Core::Channel::is ( ) const

inlinenoexcept

Check whether this channel is of a given derived type.

Template Parameters

T	A type derived from Channel.

outputPort()

OutputPort & dfx::Core::Channel::outputPort ( ) const

inlinenoexcept

Source (producer) endpoint of this channel.

pendingMessageCount()

virtual std::size_t dfx::Core::Channel::pendingMessageCount ( ) const

pure virtual

Number of messages currently pending in this channel.

Implemented in dfx::Core::SPSCChannel.

pop()

virtual std::optional< MessagePtr > dfx::Core::Channel::pop ( )

pure virtual

Pop the next message from the channel.

Returns

The next message if available, or std::nullopt if the channel is empty.

Implemented in dfx::Core::SPSCChannel.

pushMessage()

virtual bool dfx::Core::Channel::pushMessage ( MessagePtr msg )

pure virtual

Push a message into the channel from the producer side.

Parameters

msg	Message to enqueue.

Returns

true on success, false if the message could not be enqueued.

Implemented in dfx::Core::SPSCChannel.

setDeliveryHook()

void dfx::Core::Channel::setDeliveryHook ( Hooks::Delivery * hook )

inline

Set the optional delivery hook for this channel.

The hook pointer is stored as-is; it is not owned by the channel. Concrete implementations may call the hook around enqueue/dequeue/delivery.

Parameters

hook	Hook pointer, or null to disable.

Member Data Documentation

_deliveryHook

Hooks::Delivery* dfx::Core::Channel::_deliveryHook = nullptr

protected

Optional delivery hook (non-owning).

_inputPort

InputPort& dfx::Core::Channel::_inputPort

protected

Destination port (consumer).

_outputPort

OutputPort& dfx::Core::Channel::_outputPort

protected

Source port (producer).

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

• lib/dfx-core/channels/Channel.hpp