Source code for secretflow.security.compare.device_comparator

# Copyright 2022 Ant Group Co., Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from dataclasses import dataclass
from typing import List, Union

import jax.numpy as jnp

from secretflow.device import SPU, PYU, DeviceObject
from secretflow.security.compare.comparator import Comparator


@dataclass
class DeviceComparator(Comparator):
    """
    Comparator based on a device (PYU or SPU).

    Attributes:
        device: a PYU or SPU. The device where the computation hosts.
    """

    device: Union[PYU, SPU]

    def min(self, data: List[DeviceObject], axis=None):
        """The minimum of array over a given axis.

        Args:
            data: array of device objects.
            axis: optional. Same as the axis argument of :py:meth:`numpy.amin`.

        Returns:
            a device object holds the minimum.
        """
        assert data, f'Data to get min can not be None or empty'
        data = [d.to(self.device) for d in data]

        def _min(*data, axis):
            return jnp.min(jnp.array(data), axis=axis)

        return self.device(_min, static_argnames='axis')(*data, axis=axis)

    def max(self, data: List[DeviceObject], axis=None):
        """The maximum of array over a given axis.

        Args:
            data: array of device objects.
            axis: optional. Same as the axis argument of :py:meth:`numpy.amax`.

        Returns:
            a device object holds the maximum.
        """
        assert data, f'Data to get max can not be None or empty'
        data = [d.to(self.device) for d in data]

        def _max(*data, axis):
            return jnp.max(jnp.array(data), axis=axis)

        return self.device(_max, static_argnames='axis')(*data, axis=axis)