Data I/O: sources and sinks

Data I/O components connect Semantiva pipelines to the outside world:

  • Sources produce typed data from files, databases or other systems.

  • Sinks consume typed data and write it to disk, sockets, viewers or external services.

Both are regular Semantiva components with clear type contracts.

Sources

A data source typically declares an output_data_type (SVA200) and no input_data_type. It encapsulates how raw external data is loaded and wrapped into a suitable data type.

Example (conceptual):

from pathlib import Path
from semantiva import DataSource
from semantiva.examples import FloatDataType

class ToyFloatSource(DataSource):
    """Load a float from a text file (conceptual example)."""

    @classmethod
    def _get_data(cls, path: str) -> FloatDataType:
        value = float(Path(path).read_text().strip())
        return FloatDataType(value)

    @classmethod
    def output_data_type(cls):
        return FloatDataType

# Use the sample file shipped with the documentation.
result = ToyFloatSource.get_data("docs/examples/data/io_input.txt")
print(result.data)

2.5

Sinks

A data sink declares an input_data_type (SVA210) and typically does not declare an output_data_type. It takes a typed value and writes it to an external target.

from pathlib import Path
from semantiva import DataSink
from semantiva.examples import FloatDataType

class ToyFloatSink(DataSink[FloatDataType]):
    """Write a float to a text file (conceptual example)."""

    @classmethod
    def _send_data(cls, data: FloatDataType, path: str) -> None:
        Path(path).write_text(f"{data.data}\n")

    @classmethod
    def input_data_type(cls):
        return FloatDataType

# Use the sink to write an output file and confirm its contents.
value = FloatDataType(3.0)
ToyFloatSink.send_data(value, path="output.txt")
print(value.data)
print("file contains:", Path("output.txt").read_text().strip())

3.0
file contains: 3.0

In real projects you may implement I/O operations by hand or rely on extensions such as semantiva_imaging or project-specific components. The examples above are deliberately minimal to illustrate the type contracts.

Next steps