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#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you 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
#
# http://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 data import LinkState, MessageHELLO
from time import time
try:
from dispatch import *
except ImportError:
from ..stubs import *
class NeighborEngine(object):
"""
This module is responsible for maintaining this router's link-state. It runs the HELLO protocol
with the router's neighbors and notifies outbound when the list of neighbors-in-good-standing (the
link-state) changes.
"""
def __init__(self, container):
self.container = container
self.id = self.container.id
self.area = self.container.area
self.last_hello_time = 0.0
self.hello_interval = container.config.hello_interval
self.hello_max_age = container.config.hello_max_age
self.hellos = {}
self.link_state_changed = False
self.link_state = LinkState(None, self.id, self.area, 0, [])
def tick(self, now):
self._expire_hellos(now)
if now - self.last_hello_time >= self.hello_interval:
self.last_hello_time = now
self.container.send('amqp:/_local/qdxhello', MessageHELLO(None, self.id, self.area, self.hellos.keys()))
if self.link_state_changed:
self.link_state_changed = False
self.link_state.bump_sequence()
self.container.local_link_state_changed(self.link_state)
def handle_hello(self, msg, now, link_id):
if msg.id == self.id:
return
self.hellos[msg.id] = now
if msg.is_seen(self.id):
if self.link_state.add_peer(msg.id):
self.link_state_changed = True
self.container.new_neighbor(msg.id, link_id)
self.container.log(LOG_INFO, "New neighbor established: %s on link: %d" % (msg.id, link_id))
##
## TODO - Use this function to detect area boundaries
##
def _expire_hellos(self, now):
to_delete = []
for key, last_seen in self.hellos.items():
if now - last_seen > self.hello_max_age:
to_delete.append(key)
for key in to_delete:
self.hellos.pop(key)
if self.link_state.del_peer(key):
self.link_state_changed = True
self.container.lost_neighbor(key)
self.container.log(LOG_INFO, "Neighbor lost: %s" % key)
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