Class PubSubReceiver

• Defined in File pubsub_receiver.hpp

Base Type

• public holoscan::Receiver (Class Receiver)

class PubSubReceiver : public holoscan::Receiver

Pub/Sub receiver class for topic-based subscriptions.

PubSubReceiver is used to receive messages from publishers on a specific topic. It wraps the GXF nvidia::gxf::PubSubReceiver component, which is backend-agnostic and works with different transport implementations (gRPC+UCX, DDS, etc.).

Public Functions

template<typename ArgT, typename ...ArgsT, typename = std::enable_if_t<!std::is_base_of_v<::holoscan::Resource, std::decay_t<ArgT>> && (std::is_same_v<::holoscan::Arg, std::decay_t<ArgT>> || std::is_same_v<::holoscan::ArgList, std::decay_t<ArgT>>)>>
inline explicit PubSubReceiver(ArgT &&arg, ArgsT&&... args)

PubSubReceiver() = default

PubSubReceiver(const std::string &name, nvidia::gxf::PubSubReceiver *component)

inline virtual const char *gxf_typename() const override

virtual void setup(ComponentSpec &spec) override

Define the resource specification.

Parameters

spec – The reference to the component specification.

virtual void initialize() override

Initialize the component.

This method is called only once when the component is created for the first time, and use of light-weight initialization.

nvidia::gxf::PubSubReceiver *get() const

Get the underlying GXF PubSubReceiver component.

Returns

Pointer to the GXF PubSubReceiver, or nullptr if not initialized.

std::string topic_name() const

Get the topic name this receiver subscribes to.

Returns

The topic name string.

size_t matched_publisher_count() const

Get the number of matched publishers.

Returns

Number of publishers currently matched to this subscriber.

bool has_matched_publishers() const

Check if there are any matched publishers.

Returns

true if at least one publisher is matched.

std::vector<nvidia::gxf::PublisherGid> matched_publisher_gids() const

Get the GIDs of all currently matched publishers.

Returns

Snapshot vector of publisher GIDs (taken under lock).

void qos(const nvidia::gxf::QoSProfile &qos)

Set the QoS profile for this receiver.

Must be called before initialize(). The profile is forwarded to the underlying GXF PubSubReceiver during initialization. If called after initialize(), the update is ignored and a warning is logged. If not set, QoSProfile::Default() is used (best-effort, volatile, keep-last 10).

Parameters

qos – The QoS profile to apply.

inline const std::optional<nvidia::gxf::QoSProfile> &qos() const

Get the QoS profile set on this receiver (if any).

Returns

The QoS profile, or std::nullopt if none was explicitly set.