# Copyright 2016, Tresys Technology, LLC
#
# SPDX-License-Identifier: LGPL-2.1-only
#
from typing import NamedTuple
from ..policyrep import Context
from .context import ContextWrapper
from .descriptors import DiffResultDescriptor
from .difference import Difference, SymbolWrapper
class ModifiedInitialSID(NamedTuple):
"""Difference details for a modified initial SID."""
added_context: Context
removed_context: Context
class InitialSIDsDifference(Difference):
"""Determine the difference in initsids between two policies."""
added_initialsids = DiffResultDescriptor("diff_initialsids")
removed_initialsids = DiffResultDescriptor("diff_initialsids")
modified_initialsids = DiffResultDescriptor("diff_initialsids")
def diff_initialsids(self) -> None:
"""Generate the difference in initial SIDs between the policies."""
self.log.info("Generating initial SID differences from {0.left_policy} to {0.right_policy}".
format(self))
self.added_initialsids, self.removed_initialsids, matched_initialsids = self._set_diff(
(SymbolWrapper(i) for i in self.left_policy.initialsids()),
(SymbolWrapper(i) for i in self.right_policy.initialsids()))
self.modified_initialsids = dict()
for left_initialsid, right_initialsid in matched_initialsids:
# Criteria for modified initialsids
# 1. change to context
if ContextWrapper(left_initialsid.context) != ContextWrapper(right_initialsid.context):
self.modified_initialsids[left_initialsid] = ModifiedInitialSID(
right_initialsid.context, left_initialsid.context)
#
# Internal functions
#
def _reset_diff(self) -> None:
"""Reset diff results on policy changes."""
self.log.debug("Resetting initialsid differences")
self.added_initialsids = None
self.removed_initialsids = None
self.modified_initialsids = None
