# Copyright 2018, Chris PeBenito <pebenito@ieee.org>
#
# SPDX-License-Identifier: LGPL-2.1-only
#
from typing import NamedTuple
from ..policyrep import Context, Ibpkeycon
from .context import ContextWrapper
from .descriptors import DiffResultDescriptor
from .difference import Difference, Wrapper
class ModifiedIbpkeycon(NamedTuple):
"""Difference details for a modified ibpkeycon."""
rule: Ibpkeycon
added_context: Context
removed_context: Context
class IbpkeyconsDifference(Difference):
"""Determine the difference in ibpkeycons between two policies."""
added_ibpkeycons = DiffResultDescriptor("diff_ibpkeycons")
removed_ibpkeycons = DiffResultDescriptor("diff_ibpkeycons")
modified_ibpkeycons = DiffResultDescriptor("diff_ibpkeycons")
def diff_ibpkeycons(self) -> None:
"""Generate the difference in ibpkeycons between the policies."""
self.log.info(
"Generating ibpkeycon differences from {0.left_policy} to {0.right_policy}".
format(self))
self.added_ibpkeycons, self.removed_ibpkeycons, matched_ibpkeycons = \
self._set_diff(
(IbpkeyconWrapper(n) for n in self.left_policy.ibpkeycons()),
(IbpkeyconWrapper(n) for n in self.right_policy.ibpkeycons()))
self.modified_ibpkeycons = []
for left_ibpkey, right_ibpkey in matched_ibpkeycons:
# Criteria for modified ibpkeycons
# 1. change to context
if ContextWrapper(left_ibpkey.context) != ContextWrapper(right_ibpkey.context):
self.modified_ibpkeycons.append(
ModifiedIbpkeycon(left_ibpkey, right_ibpkey.context, left_ibpkey.context))
#
# Internal functions
#
def _reset_diff(self) -> None:
"""Reset diff results on policy changes."""
self.log.debug("Resetting ibpkeycon differences")
self.added_ibpkeycons = None
self.removed_ibpkeycons = None
self.modified_ibpkeycons = None
class IbpkeyconWrapper(Wrapper[Ibpkeycon]):
"""Wrap ibpkeycon statements for diff purposes."""
__slots__ = ("subnet_prefix", "low", "high")
def __init__(self, ocon: Ibpkeycon) -> None:
self.origin = ocon
self.subnet_prefix = ocon.subnet_prefix
self.low, self.high = ocon.pkeys
self.key = hash(ocon)
def __hash__(self):
return self.key
def __lt__(self, other):
return self.origin < other.origin
def __eq__(self, other):
return self.subnet_prefix == other.subnet_prefix and \
self.low == other.low and \
self.high == other.high
