proxystore.serialize

proxystore/serialize.py

Serialization functions.

SerializationError

Bases: Exception

Base Serialization Exception.

serialize

serialize(obj: Any) -> bytes

Serialize object.

Objects are serialized with different mechanisms depending on their type.

• bytes types are not serialized.
• str types are encoded to bytes.
• numpy.ndarray types are serialized using numpy.save.
• pandas.DataFrame types are serialized using to_pickle.
• polars.DataFrame types are serialized using write_ipc.
• Other types are pickled. If pickle fails, cloudpickle is used as a fallback.

Parameters:

• obj (Any) –

  Object to serialize.

Returns:

• bytes –

  Bytes that can be passed to deserialize().

Raises:

• SerializationError –

  If serializing the object fails with all available serializers. Cloudpickle is the last resort, so this error will typically be raised from a cloudpickle error.

Source code in proxystore/serialize.py

def serialize(obj: Any) -> bytes:
    """Serialize object.

    Objects are serialized with different mechanisms depending on their type.

      - [bytes][] types are not serialized.
      - [str][] types are encoded to bytes.
      - [numpy.ndarray](https://numpy.org/doc/stable/reference/generated/numpy.ndarray.html){target=_blank}
        types are serialized using
        [numpy.save](https://numpy.org/doc/stable/reference/generated/numpy.save.html){target=_blank}.
      - [pandas.DataFrame](https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.html){target=_blank}
        types are serialized using
        [to_pickle](https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.to_pickle.html){target=_blank}.
      - [polars.DataFrame](https://pola-rs.github.io/polars/py-polars/html/reference/dataframe/index.html){target=_blank}
        types are serialized using
        [write_ipc](https://docs.pola.rs/api/python/stable/reference/api/polars.DataFrame.write_ipc.html){target=_blank}.
      - Other types are
        [pickled](https://docs.python.org/3/library/pickle.html){target=_blank}.
        If pickle fails,
        [cloudpickle](https://github.com/cloudpipe/cloudpickle){target=_blank}
        is used as a fallback.

    Args:
        obj: Object to serialize.

    Returns:
        Bytes that can be passed to \
        [`deserialize()`][proxystore.serialize.deserialize].

    Raises:
        SerializationError: If serializing the object fails with all available
            serializers. Cloudpickle is the last resort, so this error will
            typically be raised from a cloudpickle error.
    """
    last_exception: Exception | None = None
    for identifier, serializer in _SERIALIZERS.items():
        if serializer.supported(obj):
            try:
                with io.BytesIO() as buffer:
                    buffer.write(identifier + b'\n')
                    serializer.serialize(obj, buffer)
                    return buffer.getvalue()
            except Exception as e:
                last_exception = e

    assert last_exception is not None
    raise SerializationError(
        f'Object of type {type(obj)} is not supported.',
    ) from last_exception

deserialize

deserialize(data: bytes) -> Any

Deserialize object.

Warning

Pickled data is not secure, and malicious pickled object can execute arbitrary code when upickled. Only unpickle data you trust.

Parameters:

• data (bytes) –

  Bytes produced by serialize().

Returns:

• Any –

  The deserialized object.

Raises:

• ValueError –

  If data is not of type bytes.

• SerializationError –

  If the identifier of data is missing or invalid. The identifier is prepended to the string in serialize() to indicate which serialization method was used (e.g., no serialization, pickle, etc.).

• SerializationError –

  If pickle or cloudpickle raise an exception when deserializing the object.

Source code in proxystore/serialize.py

def deserialize(data: bytes) -> Any:
    """Deserialize object.

    Warning:
        Pickled data is not secure, and malicious pickled object can execute
        arbitrary code when upickled. Only unpickle data you trust.

    Args:
        data: Bytes produced by
            [`serialize()`][proxystore.serialize.serialize].

    Returns:
        The deserialized object.

    Raises:
        ValueError: If `data` is not of type `bytes`.
        SerializationError: If the identifier of `data` is missing or
            invalid. The identifier is prepended to the string in
            [`serialize()`][proxystore.serialize.serialize] to indicate which
            serialization method was used (e.g., no serialization, pickle,
            etc.).
        SerializationError: If pickle or cloudpickle raise an exception
            when deserializing the object.
    """
    if not isinstance(data, bytes):
        raise ValueError(
            f'Expected data to be of type bytes, not {type(data)}.',
        )

    with io.BytesIO(data) as buffer:
        identifier = buffer.readline().strip()
        if identifier not in _SERIALIZERS:
            raise SerializationError(
                f'Unknown identifier {identifier!r} for deserialization.',
            )

        serializer = _SERIALIZERS[identifier]
        try:
            return serializer.deserialize(buffer)
        except Exception as e:
            raise SerializationError(
                'Failed to deserialize object using the '
                f'{serializer.name} serializer.',
            ) from e