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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.
#
class Sim:
def __init__(self):
self.brokers = {}
self.clients = {}
self.errors = 0
self.warnings = 0
def error(self, text):
self.errors += 1
print "###### Error:", text
def warning(self, text):
self.warnings += 1
print "###### Warning:", text
def end(self):
print "========================"
print "Errors: %d, Warnings: %d" % (self.errors, self.warnings)
print "========================"
def dumpState(self):
print "============================"
print "===== Federation State ====="
print "============================"
for broker in self.brokers:
for exchange in self.brokers[broker].exchanges:
print "Exchange %s.%s" % (broker, exchange)
for key in self.brokers[broker].exchanges[exchange].keys:
print " Key %s" % key
for queue in self.brokers[broker].exchanges[exchange].keys[key]:
print " Queue %s origins=%s" % \
(queue.name, self.brokers[broker].exchanges[exchange].keys[key][queue].originList)
def addBroker(self, name):
if name in self.brokers:
raise Exception("Broker of same name already exists")
broker = Broker(self, name)
self.brokers[name] = broker
return broker
def addClient(self, name, broker):
if name in self.clients:
raise Exception("Client of same name already exists")
client = Client(self, name, broker)
self.clients[name] = client
return client
def link(self, left, right, bidir=True):
print "====== link %s to %s, bidir=%s" % (left.tag, right.tag, bidir)
l1 = left.createLink(right)
l1.bridge("amq.direct")
if bidir:
l2 = right.createLink(left)
l2.bridge("amq.direct")
def bind(self, client, key):
print "====== bind Client(%s): k=%s" % (client.name, key)
client.bind(key)
def unbind(self, client, key):
print "====== unbind Client(%s): k=%s" % (client.name, key)
client.unbind(key)
def sendMessage(self, key, broker, body="Message Body"):
print "====== sendMessage: broker=%s k=%s" % (broker.tag, key)
msg = Message(key, body)
exchange = broker.exchanges["amq.direct"]
for client in self.clients:
self.clients[client].expect(key);
exchange.receive(key, msg, True)
for client in self.clients:
self.clients[client].checkReception()
class Destination:
def receive(self, key, msg, fromUser=False):
pass
class Client(Destination):
def __init__(self, sim, name, broker):
self.sim = sim
self.name = name
self.broker = broker
self.broker.connect(self)
self.queue = self.broker.declare_queue(name)
self.subscription = self.broker.subscribe(self, name)
self.expected = None
self.boundKeys = []
def bind(self, key):
self.boundKeys.append(key)
self.broker.bind("amq.direct", self.name, key)
def unbind(self, key):
self.boundKeys.remove(key)
self.broker.unbind("amq.direct", self.name, key)
def receive(self, key, msg, fromUser=False):
print "Client(%s) received [%s]: %s" % (self.name, key, msg.body)
if self.expected == key:
self.expected = None
else:
self.sim.error("Client(%s) received unexpected message with key [%s]" % \
(self.name, self.expected))
def expect(self, key):
if key in self.boundKeys:
self.expected = key
def checkReception(self):
if self.expected:
self.sim.error("Client(%s) never received message with key [%s]" % \
(self.name, self.expected))
class Broker(Client):
def __init__(self, sim, tag):
self.sim = sim
self.tag = tag
self.connections = {}
self.exchanges = {}
self.queues = {}
self.subscriptions = {}
self.links = {}
self.directExchange = self.declare_exchange("amq.direct")
def connect(self, client):
if client in self.connections:
raise Exception("Client already connected")
self.connections[client] = Connection(client)
def declare_queue(self, name, tag=None, exclude=None):
if name in self.queues:
raise Exception("Queue already exists")
self.queues[name] = Queue(self, name, tag, exclude)
def subscribe(self, dest, queueName):
if queueName not in self.queues:
raise Exception("Queue does not exist")
self.queues[queueName].setDest(dest)
def declare_exchange(self, name):
if name in self.exchanges:
return
exchange = Exchange(self, name)
self.exchanges[name] = exchange
return exchange
def bind(self, exchangeName, queueName, key, tagList=[], fedOp=None, origin=None):
if exchangeName not in self.exchanges:
raise Exception("Exchange not found")
if queueName not in self.queues:
raise Exception("Queue not found")
exchange = self.exchanges[exchangeName]
queue = self.queues[queueName]
exchange.bind(queue, key, tagList, fedOp, origin)
def unbind(self, exchangeName, queueName, key):
if exchangeName not in self.exchanges:
raise Exception("Exchange not found")
if queueName not in self.queues:
raise Exception("Queue not found")
exchange = self.exchanges[exchangeName]
queue = self.queues[queueName]
exchange.unbind(queue, key)
def createLink(self, other):
if other in self.links:
raise Exception("Peer broker already linked")
link = Link(self, other)
self.links[other] = link
return link
class Connection:
def __init__(self, client):
self.client = client
class Exchange(Destination):
def __init__(self, broker, name):
self.broker = broker
self.sim = broker.sim
self.name = name
self.keys = {}
self.bridges = []
def bind(self, queue, key, tagList, fedOp, origin):
if not fedOp: fedOp = "bind"
print "Exchange(%s.%s) bind q=%s, k=%s, tags=%s, op=%s, origin=%s" % \
(self.broker.tag, self.name, queue.name, key, tagList, fedOp, origin),
if self.broker.tag in tagList:
print "(tag ignored)"
return
if fedOp == "bind" or fedOp == "unbind":
if key not in self.keys:
self.keys[key] = {}
queueMap = self.keys[key]
if fedOp == "bind":
##
## Add local or federation binding case
##
if queue in queueMap:
if origin and origin in queueMap[queue].originList:
print "(dup ignored)"
elif origin:
queueMap[queue].originList.append(origin)
print "(origin added)"
else:
binding = Binding(origin)
queueMap[queue] = binding
print "(binding added)"
elif fedOp == "unbind":
##
## Delete federation binding case
##
if queue in queueMap:
binding = queueMap[queue]
if origin and origin in binding.originList:
binding.originList.remove(origin)
if len(binding.originList) == 0:
queueMap.pop(queue)
if len(queueMap) == 0:
self.keys.pop(key)
print "(last origin del)"
else:
print "(removed origin)"
else:
print "(origin not found)"
else:
print "(queue not found)"
elif fedOp == "reorigin":
print "(ok)"
self.reorigin()
elif fedOp == "hello":
print "(ok)"
else:
raise Exception("Unknown fed-opcode '%s'" % fedOp)
newTagList = []
newTagList.append(self.broker.tag)
for tag in tagList:
newTagList.append(tag)
if origin:
propOrigin = origin
else:
propOrigin = self.broker.tag
for bridge in self.bridges:
if bridge.isDynamic():
bridge.propagate(key, newTagList, fedOp, propOrigin)
def reorigin(self):
myTag = []
myTag.append(self.broker.tag)
for key in self.keys:
queueMap = self.keys[key]
found = False
for queue in queueMap:
binding = queueMap[queue]
if binding.isLocal():
found = True
if found:
for bridge in self.bridges:
if bridge.isDynamic():
bridge.propagate(key, myTag, "bind", self.broker.tag)
def unbind(self, queue, key):
print "Exchange(%s.%s) unbind q=%s, k=%s" % (self.broker.tag, self.name, queue.name, key),
if key not in self.keys:
print "(key not known)"
return
queueMap = self.keys[key]
if queue not in queueMap:
print "(queue not bound)"
return
queueMap.pop(queue)
if len(queueMap) == 0:
self.keys.pop(key)
print "(ok, remove bound-key)"
else:
print "(ok)"
count = 0
for queue in queueMap:
if len(queueMap[queue].originList) == 0:
count += 1
if count == 0:
myTag = []
myTag.append(self.broker.tag)
for bridge in self.bridges:
if bridge.isDynamic():
bridge.propagate(key, myTag, "unbind", self.broker.tag)
def receive(self, key, msg, fromUser=False):
sent = False
if key in self.keys:
queueMap = self.keys[key]
for queue in queueMap:
if queue.enqueue(msg):
sent = True
if not sent and not fromUser:
self.sim.warning("Exchange(%s.%s) received unroutable message: k=%s" % \
(self.broker.tag, self.name, key))
def addDynamicBridge(self, bridge):
if bridge in self.bridges:
raise Exception("Dynamic bridge already added to exchange")
self.bridges.append(bridge)
for b in self.bridges:
if b != bridge:
b.sendReorigin()
self.reorigin()
class Queue:
def __init__(self, broker, name, tag=None, exclude=None):
self.broker = broker
self.name = name
self.tag = tag
self.exclude = exclude
self.dest = None
def setDest(self, dest):
self.dest = dest
def enqueue(self, msg):
print "Queue(%s.%s) rcvd k=%s, tags=%s" % (self.broker.tag, self.name, msg.key, msg.tags),
if self.dest == None:
print "(dropped, no dest)"
return False
if self.exclude and msg.tagFound(self.exclude):
print "(dropped, tag)"
return False
if self.tag:
msg.appendTag(self.tag)
print "(ok)"
self.dest.receive(msg.key, msg)
return True
class Binding:
def __init__(self, origin):
self.originList = []
if origin:
self.originList.append(origin)
def isLocal(self):
return len(self.originList) == 0
class Link:
def __init__(self, local, remote):
self.local = local
self.remote = remote
self.remote.connect(self)
self.bridges = []
def bridge(self, exchangeName):
bridge = Bridge(self, exchangeName)
class Bridge:
def __init__(self, link, exchangeName):
self.link = link
self.exchangeName = exchangeName
if self.exchangeName not in link.local.exchanges:
raise Exception("Exchange not found")
self.exchange = link.local.exchanges[self.exchangeName]
self.queueName = "bridge." + link.local.tag
self.link.remote.declare_queue(self.queueName, self.link.remote.tag, self.link.local.tag)
self.link.remote.subscribe(self.exchange, self.queueName)
self.exchange.addDynamicBridge(self)
def isDynamic(self):
return True
def localTag(self):
return self.link.local.tag
def remoteTag(self):
return self.link.remote.tag
def propagate(self, key, tagList, fedOp, origin):
if self.link.remote.tag not in tagList:
self.link.remote.bind(self.exchangeName, self.queueName, key, tagList, fedOp, origin)
def sendReorigin(self):
myTag = []
myTag.append(self.link.local.tag)
self.link.remote.bind(self.exchangeName, self.queueName, "", myTag, "reorigin", "")
class Message:
def __init__(self, key, body):
self.key = key
self.body = body
self.tags = []
def appendTag(self, tag):
if tag not in self.tags:
self.tags.append(tag)
def tagFound(self, tag):
return tag in self.tags
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