Class InputContext
Defined in File io_context.hpp
Derived Type
public holoscan::gxf::GXFInputContext
(Class GXFInputContext)
-
class InputContext
Class to hold the input context.
This class provides the interface to receive the input data from the operator.
Subclassed by holoscan::gxf::GXFInputContext
Public Functions
Construct a new InputContext object.
- Parameters
execution_context – The pointer to the execution context.
op – The pointer to the operator that this context is associated with.
inputs – The references to the map of the input specs.
-
inline InputContext(ExecutionContext *execution_context, Operator *op)
Construct a new InputContext object.
inputs for the InputContext will be set to op->spec()->inputs()
- Parameters
execution_context – The pointer to GXF execution runtime
op – The pointer to the operator that this context is associated with.
-
inline ExecutionContext *execution_context() const
Get pointer to the execution context.
- Returns
The pointer to the execution context.
-
inline Operator *op() const
Return the operator that this context is associated with.
- Returns
The pointer to the operator.
-
inline std::unordered_map<std::string, std::shared_ptr<IOSpec>> &inputs() const
Return the reference to the map of the input specs.
- Returns
The reference to the map of the input specs.
-
inline bool empty(const char *name = nullptr)
Return whether the input port has any data.
For parameters with std::vector<IOSpec*> type, if all the inputs are empty, it will return true. Otherwise, it will return false.
- Parameters
name – The name of the input port to check.
- Returns
True, if it has no data, otherwise false.
-
template<typename DataT>
inline holoscan::expected<DataT, holoscan::RuntimeError> receive(const char *name = nullptr) Receive a message from the input port with the given name.
If the operator has a single input port, the name of the input port can be omitted.
If the input port with the given name and type (
DataT
) is available, it will return the data from the input port. Otherwise, it will return an object of the holoscan::unexpected class which will contain the error message. The error message can be access by calling thewhat()
method of the holoscan::unexpected object.Example:
class PingRxOp : public holoscan::ops::GXFOperator { public: HOLOSCAN_OPERATOR_FORWARD_ARGS_SUPER(PingRxOp, holoscan::ops::GXFOperator) PingRxOp() = default; void setup(OperatorSpec& spec) override { spec.input<std::shared_ptr<ValueData>>("in"); } void compute(InputContext& op_input, OutputContext&, ExecutionContext&) override { auto value = op_input.receive<std::shared_ptr<ValueData>>("in"); if (value.has_value()) { HOLOSCAN_LOG_INFO("Message received (value: {})", value->data()); } } };
- Template Parameters
DataT – The type of the data to receive.
- Parameters
name – The name of the input port to receive the data from.
- Returns
The received data.
Protected Functions
-
inline virtual bool empty_impl(const char *name = nullptr)
The implementation of the
empty
method.- Parameters
name – The name of the input port
- Returns
True if the input port is empty or by default. Otherwise, false.
-
inline virtual std::any receive_impl(const char *name = nullptr, bool no_error_message = false)
The implementation of the
receive
method.Depending on the type of the data, this method receives a message from the input port with the given name.
- Parameters
name – The name of the input port.
no_error_message – Whether to print an error message when the input port is not found.
- Returns
The data received from the input port.
Protected Attributes
-
ExecutionContext *execution_context_ = nullptr
The execution context that is associated with.
-
Operator *op_ = nullptr
The operator that this context is associated with.
-
std::unordered_map<std::string, std::shared_ptr<IOSpec>> &inputs_
The inputs.