Class DataLogger

• Defined in File data_logger.hpp

Derived Type

• public holoscan::DataLoggerResource (Class DataLoggerResource)

class DataLogger

Pure virtual interface for data loggers.

This interface defines the contract that all data loggers must implement for logging various types of data including generic std::any data, Tensors, and TensorMaps.

Subclassed by holoscan::DataLoggerResource

Public Functions

DataLogger() = default

virtual ~DataLogger() = default

virtual bool log_data(std::any data, const std::string &unique_id, int64_t acquisition_timestamp = -1, std::shared_ptr<MetadataDictionary> metadata = nullptr, IOSpec::IOType io_type = IOSpec::IOType::kOutput) = 0

Logs a message.

The unique_id for the message will have the form:

• operator_name.port_name

• operator_name.port_name:index (for multi-receivers with N:1 connection)

For distributed applications, the fragment name will also appear in the unique id:

• fragment_name.operator_name.port_name

• fragment_name.operator_name.port_name:index

Parameters

• data – The data to log, passed as std::any.

• unique_id – A unique identifier for the message.

• acquisition_timestamp – Timestamp when the data was acquired (-1 if unknown).

• metadata – Associated metadata dictionary for the message.

• io_type – The type of I/O port (kInput or kOutput).

Returns

true if logging (including serialization and sending) was successful, false otherwise.

virtual bool log_tensor_data(const std::shared_ptr<Tensor> &tensor, const std::string &unique_id, int64_t acquisition_timestamp = -1, const std::shared_ptr<MetadataDictionary> &metadata = nullptr, IOSpec::IOType io_type = IOSpec::IOType::kOutput) = 0

Logs a Tensor with optional data content logging.

This specialized method allows efficient logging of tensor metadata without the overhead of logging large tensor data arrays when only header information is needed.

The unique_id for the message will have the form:

• operator_name.port_name

• operator_name.port_name:index (for multi-receivers with N:1 connection)

For distributed applications, the fragment name will also appear in the unique id:

• fragment_name.operator_name.port_name

• fragment_name.operator_name.port_name:index

Parameters

• tensor – The Tensor to log.

• unique_id – A unique identifier for the message.

• acquisition_timestamp – Timestamp when the data was acquired (-1 if unknown).

• metadata – Associated metadata dictionary for the message.

• io_type – The type of I/O port (kInput or kOutput).

Returns

true if logging was successful, false otherwise.

virtual bool log_tensormap_data(const TensorMap &tensor_map, const std::string &unique_id, int64_t acquisition_timestamp = -1, const std::shared_ptr<MetadataDictionary> &metadata = nullptr, IOSpec::IOType io_type = IOSpec::IOType::kOutput) = 0

Logs a TensorMap with optional data content logging.

This specialized method allows efficient logging of tensor map metadata without the overhead of logging large tensor data arrays when only header information is needed.

The unique_id for the message will have the form:

• operator_name.port_name

• operator_name.port_name:index (for multi-receivers with N:1 connection)

For distributed applications, the fragment name will also appear in the unique id:

• fragment_name.operator_name.port_name

• fragment_name.operator_name.port_name:index

Parameters

• tensor_map – The TensorMap to log.

• unique_id – A unique identifier for the message.

• acquisition_timestamp – Timestamp when the data was acquired (-1 if unknown).

• metadata – Associated metadata dictionary for the message.

• io_type – The type of I/O port (kInput or kOutput).

Returns

true if logging was successful, false otherwise.

virtual bool should_log_output() const = 0

Checks if the logger should log output ports.

If False, the data logger will not be applied during op_output.emit() calls from Operator::compute.

Returns

true if the logger should log output ports, false otherwise.

virtual bool should_log_input() const = 0

Checks if the logger should log input ports.

If False, the data logger will not be applied during op_input.receive() calls from Operator::compute.

Returns

true if the logger should log input ports, false otherwise.