"""A process FDW"""

from . import ForeignDataWrapper
import statgrab


class ProcessFdw(ForeignDataWrapper):
    """A foreign datawrapper for querying system stats.

    It accepts no options.
    You can define any column named after a statgrab column.
    See the statgrab documentation.

    """

    def execute(self, quals, columns):
        # statgrab already returns its data in a format suitable
        # for Multicorn: a list (iterable) of dicts.
        # `quals` is ignored, PostgreSQL will do the filtering itself.
        return statgrab.sg_get_process_stats()