vlink::SubscriberImpl Class Reference

Transport-agnostic base for subscriber node implementations. More...

#include <subscriber_impl.h>

Inheritance diagram for vlink::SubscriberImpl:

Collaboration diagram for vlink::SubscriberImpl:

Public Member Functions
	~SubscriberImpl () override
	Destructor.
virtual bool	listen (MsgCallback &&callback)=0
	Registers the serialised-message receive callback.
virtual bool	listen (IntraMsgCallback &&callback)
	Registers the zero-copy in-process receive callback.
virtual void	set_latency_and_lost_enabled (bool enable)
	Enables or disables per-message latency and sample-loss tracking.
virtual bool	is_latency_and_lost_enabled () const
	Returns whether latency and sample-loss tracking is currently enabled.
virtual int64_t	get_latency () const
	Returns the most recently measured end-to-end message latency in microseconds.
virtual SampleLostInfo	get_lost () const
	Returns cumulative sample delivery statistics.
Public Member Functions inherited from vlink::NodeImpl
virtual void	init ()=0
	Initialises the underlying transport channel.
virtual void	deinit ()=0
	Tears down the underlying transport channel.
virtual bool	suspend ()
	Temporarily suspends message delivery without tearing down the channel.
virtual bool	resume ()
	Resumes message delivery after a suspend() call.
virtual bool	is_suspend () const
	Returns true when the node is currently suspended.
virtual void	interrupt ()
	Signals any blocking operations to unblock and return immediately.
virtual bool	is_support_loan () const
	Returns true if the transport supports zero-copy loaning.
virtual Bytes	loan (int64_t size)
	Borrows a write buffer of size bytes from the transport.
virtual bool	return_loan (const Bytes &bytes)
	Returns a previously loaned buffer to the transport.
virtual void	set_manual_unloan (bool manual_unloan)
	Configures manual unloan mode for zero-copy transports.
virtual const struct Conf *	get_conf () const
	Returns a pointer to the associated Conf configuration object.
virtual const AbstractNode *	get_abstract_node () const
	Returns a pointer to the AbstractNode peer (if any).
virtual Status::BasePtr	get_status (Status::Type type) const
	Retrieves a transport-specific status object.
virtual bool	check_version (const Version &version)
	Checks whether version matches the runtime VLink library version.
virtual bool	attach (class MessageLoop *message_loop)
	Attaches the node to a MessageLoop for callback dispatch.
virtual bool	detach ()
	Detaches the node from its MessageLoop.
class MessageLoop *	get_message_loop () const
	Returns the MessageLoop this node is attached to.
template<typename T>
const T *	get_target_conf () const
	Returns a typed pointer to the conf by downcasting to T.
void	register_status_handler (StatusCallback &&callback)
	Registers a callback for DDS status events.
bool	has_register_status () const
	Returns true if a status handler has been registered.
void	call_status (Status::BasePtr ptr)
	Dispatches a status event to the registered status handler.
void	set_property (const std::string &prop, const std::string &value)
	Sets a named transport property on this node.
std::string	get_property (const std::string &prop) const
	Retrieves a named transport property.
Conf::PropertiesMap	get_all_properties () const
	Returns a snapshot of all properties set on this node.
void	set_discovery_enabled (bool enable)
	Enables or disables discovery reporting for this node.
bool	get_discovery_enabled () const
	Returns true if discovery reporting is enabled for this node.
void	set_record_path (const std::string &path)
	Sets the file path for per-node message recording.
void	set_ssl_options (const SslOptions &options)
	Merges SSL/TLS options into the node property map.
void	try_record (ActionType action_type, const Bytes &data)
	Records a message to the global and/or per-node bag writers.
void	reset_interrupted ()
	Clears the interrupted flag set by interrupt().
bool	is_interrupted () const
	Returns true if interrupt() has been called and not yet reset.
void	init_ext ()
	Registers the node with the global DiscoveryReporter.
void	deinit_ext ()
	Deregisters the node from the global DiscoveryReporter.

Public Attributes
bool	is_listened {false}
	true after listen() has been successfully called.
Public Attributes inherited from vlink::NodeImpl
std::atomic_bool	has_suspend {false}
	Atomic suspend state flag (currently unused by default impls).
std::string	url
	Full URL string of this node (e.g. "dds://my/topic").
std::string	ser_type
	Serialisation type string (e.g. "demo.proto.PointCloud").
ImplType	impl_type {kUnknownImplType}
	Role of this implementation node.
SchemaType	schema_type {SchemaType::kUnknown}
	Coarse schema family reported to discovery and bag/proxy paths.
TransportType	transport_type {TransportType::kUnknown}
	Transport backend of this implementation node.
bool	is_cdr_type {false}
	true when using DDS native CDR serialisation.
bool	is_security_type {false}
	true when security-authenticated transport is enabled.
bool	is_discovery_enabled {true}
	Whether this node is reported to the discovery layer.
std::unique_ptr< class CpuProfiler >	profiler
	Optional per-node CPU profiler (only when global profiling is on).

Protected Member Functions
	SubscriberImpl ()
	Protected constructor; initialises the subscriber with kSubscriber role.
Protected Member Functions inherited from vlink::NodeImpl
	NodeImpl (ImplType type)
virtual	~NodeImpl ()

Additional Inherited Members
Public Types inherited from vlink::NodeImpl
using	ConnectCallback = std::function<void(bool)>
	Callback invoked when the peer connection state changes.
using	StatusCallback = std::function<void(const Status::BasePtr& ptr)>
	Callback invoked on DDS status events (e.g. deadline missed).
using	SyncCallback = std::function<void()>
	Callback invoked when a SetterImpl sync completes.
using	ReqRespCallback = std::function<void(uint64_t, const Bytes&, Bytes*)>
	Callback for ServerImpl request/response processing.
using	MsgCallback = std::function<void(const Bytes&)>
	Callback delivering a raw serialised message to a SubscriberImpl or GetterImpl.
using	IntraMsgCallback = std::function<void(const IntraData&)>
	Callback delivering an in-process IntraData message.
Static Public Member Functions inherited from vlink::NodeImpl
static void	global_init ()
	Initialises process-wide VLink singletons.

Detailed Description

Transport-agnostic base for subscriber node implementations.

Provides default (no-op) implementations for the optional latency/loss tracking interface. Concrete transport backends override listen(MsgCallback&&) to register their receive callback and, optionally, override the latency/loss methods if the transport provides that information.

Constructor & Destructor Documentation

~SubscriberImpl()

vlink::SubscriberImpl::~SubscriberImpl ( )

override

Destructor.

SubscriberImpl()

vlink::SubscriberImpl::SubscriberImpl ( )

protected

Protected constructor; initialises the subscriber with kSubscriber role.

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Member Function Documentation

get_latency()

virtual int64_t vlink::SubscriberImpl::get_latency ( ) const

nodiscardvirtual

Returns the most recently measured end-to-end message latency in microseconds.

Only meaningful when is_latency_and_lost_enabled() returns true. The default implementation returns 0. Transports that support latency measurement override this to return the measured value.

Returns

Latency in microseconds, or 0 if tracking is disabled or unsupported.

get_lost()

virtual SampleLostInfo vlink::SubscriberImpl::get_lost ( ) const

nodiscardvirtual

Returns cumulative sample delivery statistics.

Returns the total number of expected samples and the number that were lost due to queue overflow or network gaps. Only meaningful when is_latency_and_lost_enabled() returns true. The default implementation returns a zero-initialised SampleLostInfo.

Returns

SampleLostInfo containing total and lost counts.

is_latency_and_lost_enabled()

virtual bool vlink::SubscriberImpl::is_latency_and_lost_enabled ( ) const

nodiscardvirtual

Returns whether latency and sample-loss tracking is currently enabled.

The default implementation always returns false. Transports that support tracking override this to reflect the current enabled state.

Returns

true if tracking is active; false otherwise.

listen() [1/2]

virtual bool vlink::SubscriberImpl::listen ( IntraMsgCallback && callback )

virtual

Registers the zero-copy in-process receive callback.

Used exclusively on the intra:// transport to receive IntraData directly from a co-located publisher without serialisation. The default implementation logs a warning and returns false; only IntraSubscriberImpl overrides this.

Parameters

callback

Callable void(const IntraData&) invoked on every received in-process message.

Returns

true if registration succeeded; false if this transport does not support IntraData.

listen() [2/2]

virtual bool vlink::SubscriberImpl::listen ( MsgCallback && callback )

pure virtual

Registers the serialised-message receive callback.

Must be implemented by each concrete transport backend. The callback is invoked with a Bytes buffer containing the raw serialised message each time a new message arrives. After registration is_listened is set to true by the Subscriber<T> layer.

Parameters

callback

Callable void(const Bytes&) invoked on every received message.

Returns

true if registration succeeded; false on error.

set_latency_and_lost_enabled()

virtual void vlink::SubscriberImpl::set_latency_and_lost_enabled ( bool enable )

virtual

Enables or disables per-message latency and sample-loss tracking.

When enabled, the transport backend tracks message timestamps (for latency) and sequence numbers (for loss detection). The default implementation is a no-op; transports that support tracking override this method.

Parameters

enable

true to enable tracking; false to disable.

Member Data Documentation

is_listened

bool vlink::SubscriberImpl::is_listened {false}

true after listen() has been successfully called.

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

• include/vlink/impl/subscriber_impl.h