Data Exchange Object (DXO)

The Data Exchange Format (nvflare.apis.dxo.DXO) in NVIDIA FLARE standardizes the data passed between the communicating parties.

        if data is None:
            data = {}
        if meta is None:
            meta = {}

        self.data_kind = data_kind = data
        self.meta = meta

        err = self.validate()
        if err:
            raise ValueError("invalid DXO: {}".format(err))

    def get_meta_prop(self, key: str, default=None):
        if self.meta and isinstance(self.meta, dict):
            return self.meta.get(key, default)
        return default

    def set_meta_prop(self, key: str, value):
        if self.meta is None:
            self.meta = {}
        self.meta[key] = value

data_kind keeps track of the kind of data for example “WEIGHTS” or “WEIGHT_DIFF”.

meta is a dict that can contain additional properties.

The method to_shareable() produces a Shareable, and a DXO can be retrieved from a Shareable with nvflare.apis.dxo.from_shareable().

It is recommended to use DXO to maintain consistency in managing the data throughout the FL system.