1 files changed, 143 insertions, 0 deletions
diff --git a/qpid/extras/dispatch/src/py/router/link.py b/qpid/extras/dispatch/src/py/router/link.py
new file mode 100644
index 0000000000..38494e71b7
--- /dev/null
+++ b/qpid/extras/dispatch/src/py/router/link.py
@@ -0,0 +1,143 @@
+#
+# 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 MessageRA, MessageLSU, MessageLSR
+from time import time
+
+TRACE    = 0
+DEBUG    = 1
+INFO     = 2
+NOTICE   = 3
+WARNING  = 4
+ERROR    = 5
+CRITICAL = 6
+
+class LinkStateEngine(object):
+  """
+  This module is responsible for running the Link State protocol and maintaining the set
+  of link states that are gathered from the domain.  It notifies outbound when changes to
+  the link-state-collection are detected.
+  """
+  def __init__(self, container):
+    self.container = container
+    self.id = self.container.id
+    self.area = self.container.area
+    self.ra_interval = self.container.config.ra_interval
+    self.remote_ls_max_age = self.container.config.remote_ls_max_age
+    self.last_ra_time = 0
+    self.collection = {}
+    self.collection_changed = False
+    self.mobile_seq = 0
+    self.needed_lsrs = {}
+
+
+  def tick(self, now):
+    self._expire_ls(now)
+    self._send_lsrs()
+
+    if now - self.last_ra_time >= self.ra_interval:
+      self.last_ra_time = now
+      self._send_ra()
+
+    if self.collection_changed:
+      self.collection_changed = False
+      self.container.log(INFO, "New Link-State Collection:")
+      for a,b in self.collection.items():
+        self.container.log(INFO, "  %s => %r" % (a, b.peers))
+      self.container.ls_collection_changed(self.collection)
+
+
+  def handle_ra(self, msg, now):
+    if msg.id == self.id:
+      return
+    if msg.id in self.collection:
+      ls = self.collection[msg.id]
+      ls.last_seen = now
+      if ls.ls_seq < msg.ls_seq:
+        self.needed_lsrs[(msg.area, msg.id)] = None
+    else:
+      self.needed_lsrs[(msg.area, msg.id)] = None
+
+
+  def handle_lsu(self, msg, now):
+    if msg.id == self.id:
+      return
+    if msg.id in self.collection:
+      ls = self.collection[msg.id]
+      if ls.ls_seq < msg.ls_seq:
+        ls = msg.ls
+        self.collection[msg.id] = ls
+        self.collection_changed = True
+      ls.last_seen = now
+    else:
+      ls = msg.ls
+      self.collection[msg.id] = ls
+      self.collection_changed = True
+      ls.last_seen = now
+      self.container.log(INFO, "Learned link-state from new router: %s" % msg.id)
+    # Schedule LSRs for any routers referenced in this LS that we don't know about
+    for _id in msg.ls.peers:
+      if _id not in self.collection:
+        self.needed_lsrs[(msg.area, _id)] = None
+
+
+  def handle_lsr(self, msg, now):
+    if msg.id == self.id:
+      return
+    if self.id not in self.collection:
+      return
+    my_ls = self.collection[self.id]
+    self.container.send('_topo.%s.%s' % (msg.area, msg.id), MessageLSU(None, self.id, self.area, my_ls.ls_seq, my_ls))
+
+
+  def new_local_link_state(self, link_state):
+    self.collection[self.id] = link_state
+    self.collection_changed = True
+    self._send_ra()
+
+  def set_mobile_sequence(self, seq):
+    self.mobile_seq = seq
+
+
+  def get_collection(self):
+    return self.collection
+
+
+  def _expire_ls(self, now):
+    to_delete = []
+    for key, ls in self.collection.items():
+      if key != self.id and now - ls.last_seen > self.remote_ls_max_age:
+        to_delete.append(key)
+    for key in to_delete:
+      ls = self.collection.pop(key)
+      self.collection_changed = True
+      self.container.log(INFO, "Expired link-state from router: %s" % key)
+
+
+  def _send_lsrs(self):
+    for (_area, _id) in self.needed_lsrs.keys():
+      self.container.send('_topo.%s.%s' % (_area, _id), MessageLSR(None, self.id, self.area))
+    self.needed_lsrs = {}
+
+
+  def _send_ra(self):
+    ls_seq = 0
+    if self.id in self.collection:
+      ls_seq = self.collection[self.id].ls_seq
+    self.container.send('_topo.%s.all' % self.area, MessageRA(None, self.id, self.area, ls_seq, self.mobile_seq))