Class GXFOperator - NVIDIA Docs

Defined in File gxf_operator.hpp

Inheritance Relationships

Base Type

public holoscan::Operator (Class Operator)

Derived Type

public holoscan::ops::GXFCodeletOp (Class GXFCodeletOp)

Class Documentation

class GXFOperator : public holoscan::Operator

Subclassed by holoscan::ops::GXFCodeletOp

Public Functions

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

Construct a new GXFOperator object.

Parameters

arg – The first argument to be passed to the operator.
args – The remaining arguments to be passed to the operator.

inline GXFOperator()

virtual void initialize() override

Initialize the GXF operator.

This function is called when the fragment is initialized by Executor::initialize_fragment().

This sets the operator type to holoscan::Operator::OperatorType::kGXF.

virtual const char *gxf_typename() const = 0

Get the type name of the GXF component.

The returned string is the type name of the GXF component and is used to create the GXF component.

Example: “nvidia::holoscan::Source”

Returns: The type name of the GXF component.

inline gxf_context_t gxf_context() const

Get the GXF context object.

Returns: The GXF context object.

inline void gxf_eid(gxf_uid_t gxf_eid)

Set GXF entity ID.

Parameters: gxf_eid – The GXF entity ID.

inline gxf_uid_t gxf_eid() const

Get the GXF entity ID.

Returns: The GXF entity ID.

inline void gxf_cid(gxf_uid_t gxf_cid)

Set the GXF component ID.

Parameters: gxf_cid – The GXF component ID.

inline gxf_uid_t gxf_cid() const

Get the GXF component ID.

Returns: The GXF component ID.

std::string gxf_entity_group_name() const: The name of the entity group this operator belongs.

virtual YAML::Node to_yaml_node() const override

Get a YAML representation of the operator.

Returns: YAML node including type, specs, conditions and resources of the operator in addition to the base component properties.

Public Static Functions

template<typename typeT> static inline void register_converter()

Register the argument setter and the GXF parameter adaptor for the given type.

If the GXF operator has an argument with a custom type, both the argument setter and GXF parameter adaptor must be registered using this method.

The argument setter is used to set the value of the argument from the YAML configuration, and the GXF parameter adaptor is used to set the value of the GXF parameter from the argument value in YAML::Node object.

This method can be called in the initialization phase of the operator (e.g., initialize()). The example below shows how to register the argument setter for the custom type (Vec3):

Copy
Copied!

            
            void MyGXFOp::initialize() {
  register_converter<Vec3>();

  holoscan::ops::GXFOperator::initialize();
}

It is assumed that YAML::convert<T>::encode and YAML::convert<T>::decode are implemented for the given type. You need to specialize the YAML::convert<> template class.

For example, suppose that you had a Vec3 class with the following members:

Copy
Copied!

            
            struct Vec3 {
  // make sure you have overloaded operator==() for the comparison
  double x, y, z;
};

You can define the YAML::convert<Vec3> as follows in a ‘.cpp’ file:

Copy
Copied!

            
            namespace YAML {
template<>
struct convert<Vec3> {
  static Node encode(const Vec3& rhs) {
    Node node;
    node.push_back(rhs.x);
    node.push_back(rhs.y);
    node.push_back(rhs.z);
    return node;
  }

  static bool decode(const Node& node, Vec3& rhs) {
    if(!node.IsSequence() || node.size() != 3) {
      return false;
    }

    rhs.x = node[0].as<double>();
    rhs.y = node[1].as<double>();
    rhs.z = node[2].as<double>();
    return true;
  }
};
}

Please refer to the yaml-cpp documentation for more details.

Template Parameters: typeT – The type of the argument to register.

Protected Functions

virtual gxf_uid_t add_codelet_to_graph_entity() override

This method is invoked by ‘GXFExecutor::initialize_operator(Operator* op)’ during the initialization of the operator. By overriding this method, additional setup tasks are performed for the operator, including:

Initializing the spec_ object with the codelet’s parameters.

Returns: The codelet component id corresponding to GXF codelet.

virtual void set_parameters() override: This method is invoked at the end of ‘GXFExecutor::initialize_operator(Operator* op)’ during the initialization of the operator. By overriding this method, we can modify how GXF Codelet’s parameters are set from the arguments.

Protected Attributes

gxf_context_t gxf_context_ = nullptr: The GXF context.

gxf_uid_t gxf_eid_ = 0: GXF entity ID.

gxf_uid_t gxf_cid_ = 0: The GXF component ID.

nvidia::gxf::Handle<nvidia::gxf::Codelet> codelet_handle_: The codelet handle.

std::string gxf_typename_ = "unknown_gxf_typename": The GXF type name (used for GXFCodeletOp)

Protected Static Functions

template<typename typeT> static inline void register_parameter_adaptor()

Register the GXF parameter adaptor for the given type.

Please refer to the documentation of register_converter() for more details.

Template Parameters: typeT – The type of the argument to register.