Callback interface for session events common to both client and server mode. More...

#include <session_callbacks.h>

Inheritance diagram for quicr::Session::Callbacks:

Public Member Functions
virtual	~Callbacks ()=default
	Destroy the callback interface. More...

virtual Expected< void, Error< ErrorCode > >	SetupReceived (const std::shared_ptr< Session > &session, const SetupAttributes &setup_attributes)
	Callback on receipt of the peer's SETUP message. More...

virtual void	OnStreamClosed (std::uint64_t stream_id, StreamClosedFlag flag)
	Notify that a QUIC stream closed. More...

virtual void	StatusChanged (const std::shared_ptr< Session > &session, Status status)
	Callback notification for status/state change. More...

virtual void	MetricsSampled (const std::shared_ptr< Session > &session, const ConnectionMetrics &metrics)
	Notification callback to provide sampled connection metrics. More...

virtual Reply< const PublishResponse, PublishErrorCode >	PublishReceived (const std::shared_ptr< Session > &session, std::uint64_t request_id, const PublishAttributes &publish_attributes, std::weak_ptr< SubscribeNamespaceHandler > sub_ns_handler)
	Callback notification for new publish received. More...

virtual Reply< void, PublishNamespaceErrorCode >	PublishNamespaceReceived (const std::shared_ptr< Session > &session, const TrackNamespace &track_namespace, const PublishNamespaceAttributes &publish_namespace_attributes)
	Callback notification for announce received by subscribe namespace. More...

virtual Reply< const FetchResponse, FetchErrorCode >	StandaloneFetchReceived (const std::shared_ptr< Session > &session, std::uint64_t request_id, const FullTrackName &track_full_name, const StandaloneFetchAttributes &attributes)
	Event to run on receiving a Standalone Fetch request. More...

virtual Reply< const FetchResponse, FetchErrorCode >	JoiningFetchReceived (const std::shared_ptr< Session > &session, std::uint64_t request_id, const FullTrackName &track_full_name, const JoiningFetchAttributes &attributes)
	Event to run on receiving a Joining Fetch request. More...

virtual Reply< void, FetchErrorCode >	FetchCancelReceived (const std::shared_ptr< Session > &session, std::uint64_t request_id)
	Callback notification on receiving a FetchCancel message. More...

virtual Reply< TrackStatusResponse, RequestErrorCode >	TrackStatusReceived (const std::shared_ptr< Session > &session, const FullTrackName &track_full_name)
	Callback notification for track status message received. More...

Detailed Description

Callback interface for session events common to both client and server mode.

Callbacks that answer an inbound request return a Reply, which carries either the response or a reason code for rejecting it. The session sends the protocol message from that reply and correlates it with the request itself, so there is nothing further for the application to call and no request identifier for it to keep.

Return a value to accept, or an Unexpected<Error<E>> holding a reason code, optional reason string, and optional redirect to reject. A Reply<void, E> accepts by returning {}.

An answer that cannot be given straight away is deferred with Reply::Defer(). Its producer is called on the session's message-handling thread and must start, rather than perform, slow work there. When that work completes, invoking the supplied completion callback marshals the response back to the transport notification thread.

Callbacks are invoked on the transport notify thread, which also carries stream and connection events, so an immediate reply must return promptly; anything slow belongs in a deferred one. Each reply is answered exactly once. The transport catches exceptions that escape the producer while it is invoked or the continuation after it is queued; either case can leave the request unanswered until the peer times it out. Exceptions on an application-created worker thread remain the application's responsibility.

A callback that is not overridden keeps its default, given per method below.

Constructor & Destructor Documentation

◆ ~Callbacks()

virtual quicr::Session::Callbacks::~Callbacks ( )

virtualdefault

Destroy the callback interface.

Member Function Documentation

◆ FetchCancelReceived()

virtual Reply<void, FetchErrorCode> quicr::Session::Callbacks::FetchCancelReceived	(	const std::shared_ptr< Session > &	session,
		std::uint64_t	request_id
	)

virtual

Callback notification on receiving a FetchCancel message.

Parameters

request_id	Request ID received.
session	Session that received the cancellation.

Returns: Immediate or deferred acknowledgment, or error.

◆ JoiningFetchReceived()

virtual Reply<const FetchResponse, FetchErrorCode> quicr::Session::Callbacks::JoiningFetchReceived	(	const std::shared_ptr< Session > &	session,
		std::uint64_t	request_id,
		const FullTrackName &	track_full_name,
		const JoiningFetchAttributes &	attributes
	)

virtual

Event to run on receiving a Joining Fetch request.

Defaults to rejecting with kInternalError, since fetch is not served unless implemented.

Parameters

request_id	Request ID received.
session	Session that received the request.
track_full_name	Track full name
attributes	Fetch attributes received.

Returns: Immediate or deferred fetch response, or rejection reason.

◆ MetricsSampled()

virtual void quicr::Session::Callbacks::MetricsSampled	(	const std::shared_ptr< Session > &	session,
		const ConnectionMetrics &	metrics
	)

virtual

Notification callback to provide sampled connection metrics.

Invoked every Config::metrics_sample_ms in either client or server mode. The period based metrics reset after this callback, so a value not read here is lost. Per track metrics for the same period follow this call, via PublishTrackHandler::MetricsSampled and SubscribeTrackHandler::MetricsSampled, sharing the same last_sample_time.

Invoked on the transport notify thread, which also carries stream and connection events. Return promptly; a slow implementation backs the queue up and other notifications are dropped to make room.

Parameters

session	The session the metrics belong to
metrics	Copy of the connection metrics for the sample period

◆ OnStreamClosed()

virtual void quicr::Session::Callbacks::OnStreamClosed	(	std::uint64_t	stream_id,
		StreamClosedFlag	flag
	)

virtual

Notify that a QUIC stream closed.

Parameters

stream_id	Identifier of the closed stream.
flag	Event that closed the stream direction.

Reimplemented in quicr::Session::ServerCallbacks.

◆ PublishNamespaceReceived()

virtual Reply<void, PublishNamespaceErrorCode> quicr::Session::Callbacks::PublishNamespaceReceived	(	const std::shared_ptr< Session > &	session,
		const TrackNamespace &	track_namespace,
		const PublishNamespaceAttributes &	publish_namespace_attributes
	)

virtual

Callback notification for announce received by subscribe namespace.

Client mode only. Called when a PUBLISH_NAMESPACE is received for a subscribed prefix.

Parameters

track_namespace	Track namespace
session	Session that received the request.
publish_namespace_attributes	Publish announce attributes received

Returns: Immediate or deferred success, or rejection reason.

◆ PublishReceived()

virtual Reply<const PublishResponse, PublishErrorCode> quicr::Session::Callbacks::PublishReceived	(	const std::shared_ptr< Session > &	session,
		std::uint64_t	request_id,
		const PublishAttributes &	publish_attributes,
		std::weak_ptr< SubscribeNamespaceHandler >	sub_ns_handler
	)

virtual

Callback notification for new publish received.

Return the publish response to accept. Defaults to rejecting with kNotSupported.

Parameters

request_id	Incoming publish request ID
session	Session that received the request.
publish_attributes	Attributes of the publish
sub_ns_handler	Matching subscribe namespace handler, if any

Returns: Immediate or deferred acceptance response, or rejection reason.

◆ SetupReceived()

virtual Expected<void, Error<ErrorCode> > quicr::Session::Callbacks::SetupReceived	(	const std::shared_ptr< Session > &	session,
		const SetupAttributes &	setup_attributes
	)

virtual

Callback on receipt of the peer's SETUP message.

Returning an error disconnects the session.

Parameters

session	The session receiving SETUP
setup_attributes	Peer setup attributes received

Returns: Success to continue setup, or an error that disconnects the session.

Examples: simple_publish/main.cpp, and simple_subscribe/main.cpp.

◆ StandaloneFetchReceived()

virtual Reply<const FetchResponse, FetchErrorCode> quicr::Session::Callbacks::StandaloneFetchReceived	(	const std::shared_ptr< Session > &	session,
		std::uint64_t	request_id,
		const FullTrackName &	track_full_name,
		const StandaloneFetchAttributes &	attributes
	)

virtual

Event to run on receiving a Standalone Fetch request.

Defaults to rejecting with kInternalError, since fetch is not served unless implemented.

Parameters

request_id	Request ID received.
session	Session that received the request.
track_full_name	Track full name
attributes	Fetch attributes received.

Returns: Immediate or deferred fetch response, or rejection reason.

◆ StatusChanged()

virtual void quicr::Session::Callbacks::StatusChanged	(	const std::shared_ptr< Session > &	session,
		Status	status
	)

virtual

Callback notification for status/state change.

Callback notification indicates state change of connection, such as disconnected. May be invoked in either client or server mode.

Parameters

session	The session whose status changed
status	Changed Status value

◆ TrackStatusReceived()

virtual Reply<TrackStatusResponse, RequestErrorCode> quicr::Session::Callbacks::TrackStatusReceived	(	const std::shared_ptr< Session > &	session,
		const FullTrackName &	track_full_name
	)

virtual

Callback notification for track status message received.

Defaults to accepting with an empty TrackStatusResponse.

Parameters

track_full_name	Track full name
session	Session that received the query.

Returns: Immediate or deferred status response, or rejection reason.

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

include/quicr/session_callbacks.h

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ ~Callbacks()

Member Function Documentation

◆ FetchCancelReceived()

◆ JoiningFetchReceived()

◆ MetricsSampled()

◆ OnStreamClosed()

◆ PublishNamespaceReceived()

◆ PublishReceived()

◆ SetupReceived()

◆ StandaloneFetchReceived()

◆ StatusChanged()

◆ TrackStatusReceived()