# Copyright 2015, Tresys Technology, LLC
#
# SPDX-License-Identifier: LGPL-2.1-only
#
from typing import NamedTuple, Set
from .descriptors import DiffResultDescriptor
from .difference import Difference, SymbolWrapper
class ModifiedCommon(NamedTuple):
"""Difference details for a modified common permission set."""
added_perms: Set[str]
removed_perms: Set[str]
matched_perms: Set[str]
class CommonDifference(Difference):
"""
Determine the difference in common permission sets
between two policies.
"""
added_commons = DiffResultDescriptor("diff_commons")
removed_commons = DiffResultDescriptor("diff_commons")
modified_commons = DiffResultDescriptor("diff_commons")
def diff_commons(self) -> None:
"""Generate the difference in commons between the policies."""
self.log.info(
"Generating common differences from {0.left_policy} to {0.right_policy}".format(self))
self.added_commons, self.removed_commons, matched_commons = self._set_diff(
(SymbolWrapper(c) for c in self.left_policy.commons()),
(SymbolWrapper(c) for c in self.right_policy.commons()))
self.modified_commons = dict()
for left_common, right_common in matched_commons:
# Criteria for modified commons
# 1. change to permissions
added_perms, removed_perms, matched_perms = self._set_diff(left_common.perms,
right_common.perms,
unwrap=False)
if added_perms or removed_perms:
self.modified_commons[left_common] = ModifiedCommon(added_perms,
removed_perms,
matched_perms)
#
# Internal functions
#
def _reset_diff(self) -> None:
"""Reset diff results on policy changes."""
self.log.debug("Resetting common differences")
self.added_commons = None
self.removed_commons = None
self.modified_commons = None
