class RemoteBroker: def __init__(self, hostname, port, request_queue_name, response_queue_name, request_timeout_millis): hosts = [(hostname, port)] connect_timeout = 10 self.conn = Connection(host_and_ports=hosts, timeout=connect_timeout) self.conn.start() self.conn.connect(wait=True) self.request_queue_name = request_queue_name self.response_queue_name = response_queue_name self.request_timeout_millis = request_timeout_millis self._timer = None def acknowledge(self, headers): self.conn.ack(headers['message-id'], headers['subscription']) def publish(self, response): self.conn.send(body=json.dumps(response, separators=(',', ':')), destination=self.response_queue_name) def subscribe(self, handling_strategy, audit): listener = Listener(self, handling_strategy, self.start_timer, self.stop_timer, audit) self.conn.set_listener('listener', listener) self.conn.subscribe(destination=self.request_queue_name, id=1, ack='client-individual') self.start_timer() def respond_to(self, headers, response): self.acknowledge(headers) self.publish( OrderedDict([('result', response.result), ('error', None), ('id', response.id)])) def stop(self): self.conn.unsubscribe(1) self.conn.remove_listener('listener') def close(self): self.conn.disconnect() def is_connected(self): return self.conn.is_connected() def stop_timer(self): if self._timer is not None: self._timer.cancel() def start_timer(self): self._timer = Timer(self.request_timeout_millis / 1000.00, self.close) self._timer.start()
class StompCLI(ConnectionListener): def __init__(self, host='localhost', port=61613, user='', passcode=''): self.c = Connection([(host, port)], user, passcode) self.c.set_listener('', self) self.c.start() def __print_async(self, frame_type, headers, body): print "\r \r", print frame_type for header_key in headers.keys(): print '%s: %s' % (header_key, headers[header_key]) print print body print '> ', sys.stdout.flush() def on_connecting(self, host_and_port): self.c.connect(wait=True) def on_disconnected(self): print "lost connection" def on_message(self, headers, body): self.__print_async("MESSAGE", headers, body) def on_error(self, headers, body): self.__print_async("ERROR", headers, body) def on_receipt(self, headers, body): self.__print_async("RECEIPT", headers, body) def on_connected(self, headers, body): print 'connected' self.__print_async("CONNECTED", headers, body) def ack(self, args): ''' Usage: ack <message-id> [transaction-id] Required Parameters: message-id - the id of the message being acknowledged Optional Parameters: transaction-id - the acknowledgement should be a part of the named transaction Description: The command 'ack' is used to acknowledge consumption of a message from a subscription using client acknowledgment. When a client has issued a 'subscribe' with the ack flag set to client, any messages received from that destination will not be considered to have been consumed (by the server) until the message has been acknowledged. ''' if len(args) < 3: self.c.ack(message_id=args[1]) else: self.c.ack(message_id=args[1], transaction=args[2]) def abort(self, args): ''' Usage: abort <transaction-id> Required Parameters: transaction-id - the transaction to abort Description: Roll back a transaction in progress. ''' self.c.abort(transaction=args[1]) def begin(self, args): ''' Usage: begin Description: Start a transaction. Transactions in this case apply to sending and acknowledging - any messages sent or acknowledged during a transaction will be handled atomically based on the transaction. ''' print 'transaction id: %s' % self.c.begin() def commit(self, args): ''' Usage: commit <transaction-id> Required Parameters: transaction-id - the transaction to commit Description: Commit a transaction in progress. ''' if len(args) < 2: print 'expecting: commit <transid>' else: print 'committing %s' % args[1] self.c.commit(transaction=args[1]) def disconnect(self, args): ''' Usage: disconnect Description: Gracefully disconnect from the server. ''' try: self.c.disconnect() except NotConnectedException: pass # ignore if no longer connected def send(self, args): ''' Usage: send <destination> <message> Required Parameters: destination - where to send the message message - the content to send Description: Sends a message to a destination in the messaging system. ''' if len(args) < 3: print 'expecting: send <destination> <message>' else: self.c.send(destination=args[1], message=' '.join(args[2:])) def sendtrans(self, args): ''' Usage: sendtrans <destination> <transaction-id> <message> Required Parameters: destination - where to send the message transaction-id - the id of the transaction in which to enlist this message message - the content to send Description: Sends a message to a destination in the message system, using a specified transaction. ''' if len(args) < 3: print 'expecting: sendtrans <destination> <transaction-id> <message>' else: self.c.send(destination=args[1], message="%s\n" % ' '.join(args[3:]), transaction=args[2]) def subscribe(self, args): ''' Usage: subscribe <destination> [ack] Required Parameters: destination - the name to subscribe to Optional Parameters: ack - how to handle acknowledgements for a message; either automatically (auto) or manually (client) Description: Register to listen to a given destination. Like send, the subscribe command requires a destination header indicating which destination to subscribe to. The ack parameter is optional, and defaults to auto. ''' if len(args) < 2: print 'expecting: subscribe <destination> [ack]' elif len(args) > 2: print 'subscribing to "%s" with acknowledge set to "%s"' % ( args[1], args[2]) self.c.subscribe(destination=args[1], ack=args[2]) else: print 'subscribing to "%s" with auto acknowledge' % args[1] self.c.subscribe(destination=args[1], ack='auto') def unsubscribe(self, args): ''' Usage: unsubscribe <destination> Required Parameters: destination - the name to unsubscribe from Description: Remove an existing subscription - so that the client no longer receive messages from that destination. ''' if len(args) < 2: print 'expecting: unsubscribe <destination>' else: print 'unsubscribing from "%s"' % args[1] self.c.unsubscribe(destination=args[1]) def stats(self, args): ''' Usage: stats [on|off] Description: Record statistics on messages sent, received, errors, etc. If no argument (on|off) is specified, dump the current statistics. ''' if len(args) < 2: stats = self.c.get_listener('stats') if stats: print stats else: print 'No stats available' elif args[1] == 'on': self.c.set_listener('stats', StatsListener()) elif args[1] == 'off': self.c.remove_listener('stats') else: print 'expecting: stats [on|off]' def help(self, args): ''' Usage: help [command] Description: Display info on a specified command, or a list of available commands ''' if len(args) == 1: print 'Usage: help <command>, where command is one of the following:' print ' ' for f in dir(self): if f.startswith('_') or f.startswith('on_') or f == 'c': continue else: print '%s ' % f, print '' return elif not hasattr(self, args[1]): print 'There is no command "%s"' % args[1] return func = getattr(self, args[1]) if hasattr(func, '__doc__') and getattr(func, '__doc__') is not None: print func.__doc__ else: print 'There is no help for command "%s"' % args[1]
class EventListener(ConnectionListener): def __init__(self, host_and_ports, topic, username=None, password=None): self.topic = topic self.host_and_ports = host_and_ports self.username = username self.password = password self.should_reconnect = True self.conn = Connection(host_and_ports) self.conn.set_listener('', self) self.logger = logging.getLogger(EventListener.__name__) self.subscription_id = 94 def _connect_and_subscribe(self, ack='auto'): conn = self.conn try: self.logger.info('tring to connect AMQ: ' + str(self.host_and_ports)) conn.connect(self.username, self.password, wait=True) conn.subscribe(destination=self.topic, id=self.subscription_id, ack=ack) except ConnectFailedException as e: self.logger.exception( 'failed to connect AMQ: ' + str(self.host_and_ports) ) def _disconnect(self): self.conn.disconnect() def start_listening(self, reactor, stat_driver, ack='auto'): """ :param ack: either auto, client or client-individual """ self.should_reconnect = True self.reactor = reactor self.stat_driver = stat_driver self._connect_and_subscribe(ack) def stop_listening(self): self.should_reconnect = False self._disconnect() def on_connecting(self, host_and_port): pass def on_disconnected(self): # TODO: if exception occurs here, will the listener exit? self.logger.warn( 'connection to amq %s is closed unexpectedly' % str(self.host_and_ports) ) while self.should_reconnect: try: self._connect_and_subscribe() except ConnectFailedException as e: self.logger.exception( 'failed to reconnect to amq: ' + str(self.host_and_ports) ) time.sleep(5) else: break def on_message(self, headers, message): # TODO: should we validate the message format and field type here? try: event = Event.from_json(message) self.stat_driver.add_event(event) self.reactor.dispatch_event(event) except: self.logger.exception('failed to process message: ' + message) else: msg_id = headers['message-id'] self.conn.ack(msg_id, self.subscription_id) def on_ggGerror(self, headers, message): print('received an error "%s"' % message)
class Consumer(ConnectionListener): def __init__(self, host_and_ports, topic, handler, username=None, password=None): self.topic = topic self.host_and_ports = host_and_ports self.handler = handler self.username = username self.password = password self.should_reconnect = True self.conn = Connection(host_and_ports) self.conn.set_listener('', self) self.logger = logging.getLogger(Consumer.__name__) # a random value self.subscription_id = 95 def _connect_and_subscribe(self, ack='auto'): conn = self.conn try: self.logger.info('tring to connect AMQ: ' + str(self.host_and_ports)) conn.connect(self.username, self.password, wait=True) conn.subscribe(destination=self.topic, id=self.subscription_id, ack=ack) except ConnectFailedException as e: self.logger.exception('failed to connect AMQ: ' + str(self.host_and_ports)) def _disconnect(self): self.conn.disconnect() def on_disconnected(self): # TODO: if exception occurs here, will the listener exit? self.logger.warn('connection to amq %s is closed unexpectedly' % str(self.host_and_ports)) while self.should_reconnect: try: self._connect_and_subscribe() except ConnectFailedException as e: self.logger.exception('failed to reconnect to amq: ' + str(self.host_and_ports)) time.sleep(5) else: break def on_message(self, headers, message): # TODO: should we validate the message format and field type here? # TODO: if exception occurs and not ack, will the same message trigger # this method again? try: msg = json.loads(message) self.handler.handle(msg) except: self.logger.exception('failed to process message: ' + message) else: msg_id = headers['message-id'] self.conn.ack(msg_id, self.subscription_id) def start(self, ack='auto'): """ :param ack: either auto, client or client-individual """ self.should_reconnect = True self._connect_and_subscribe(ack) def stop(self): self.should_reconnect = False self._disconnect()
class StompCLI(ConnectionListener): def __init__(self, host='localhost', port=61613, user='', passcode=''): self.c = Connection([(host, port)], user, passcode) self.c.set_listener('', self) self.c.start() def __print_async(self, frame_type, headers, body): print "\r \r", print frame_type for header_key in headers.keys(): print '%s: %s' % (header_key, headers[header_key]) print print body print '> ', sys.stdout.flush() def on_connecting(self, host_and_port): self.c.connect(wait=True) def on_disconnected(self): print "lost connection" def on_message(self, headers, body): self.__print_async("MESSAGE", headers, body) def on_error(self, headers, body): self.__print_async("ERROR", headers, body) def on_receipt(self, headers, body): self.__print_async("RECEIPT", headers, body) def on_connected(self, headers, body): print 'connected' self.__print_async("CONNECTED", headers, body) def ack(self, args): ''' Usage: ack <message-id> [transaction-id] Required Parameters: message-id - the id of the message being acknowledged Optional Parameters: transaction-id - the acknowledgement should be a part of the named transaction Description: The command 'ack' is used to acknowledge consumption of a message from a subscription using client acknowledgment. When a client has issued a 'subscribe' with the ack flag set to client, any messages received from that destination will not be considered to have been consumed (by the server) until the message has been acknowledged. ''' if len(args) < 3: self.c.ack(message_id=args[1]) else: self.c.ack(message_id=args[1], transaction=args[2]) def abort(self, args): ''' Usage: abort <transaction-id> Required Parameters: transaction-id - the transaction to abort Description: Roll back a transaction in progress. ''' self.c.abort(transaction=args[1]) def begin(self, args): ''' Usage: begin Description: Start a transaction. Transactions in this case apply to sending and acknowledging - any messages sent or acknowledged during a transaction will be handled atomically based on the transaction. ''' print 'transaction id: %s' % self.c.begin() def commit(self, args): ''' Usage: commit <transaction-id> Required Parameters: transaction-id - the transaction to commit Description: Commit a transaction in progress. ''' if len(args) < 2: print 'expecting: commit <transid>' else: print 'committing %s' % args[1] self.c.commit(transaction=args[1]) def disconnect(self, args): ''' Usage: disconnect Description: Gracefully disconnect from the server. ''' try: self.c.disconnect() except NotConnectedException: pass # ignore if no longer connected def send(self, args): ''' Usage: send <destination> <message> Required Parameters: destination - where to send the message message - the content to send Description: Sends a message to a destination in the messaging system. ''' if len(args) < 3: print 'expecting: send <destination> <message>' else: self.c.send(destination=args[1], message=' '.join(args[2:])) def sendreply(self, args): ''' Usage: sendreply <destination> <correlation-id> <message> Required Parameters: destination - where to send the message correlation-id - the correlating identifier to send with the response message - the content to send Description: Sends a reply message to a destination in the messaging system. ''' if len(args) < 4: print 'expecting: sendreply <destination> <correlation-id> <message>' else: self.c.send(destination=args[1], message="%s\n" % ' '.join(args[3:]), headers={'correlation-id': args[2]}) def sendtrans(self, args): ''' Usage: sendtrans <destination> <transaction-id> <message> Required Parameters: destination - where to send the message transaction-id - the id of the transaction in which to enlist this message message - the content to send Description: Sends a message to a destination in the message system, using a specified transaction. ''' if len(args) < 3: print 'expecting: sendtrans <destination> <transaction-id> <message>' else: self.c.send(destination=args[1], message="%s\n" % ' '.join(args[3:]), transaction=args[2]) def subscribe(self, args): ''' Usage: subscribe <destination> [ack] Required Parameters: destination - the name to subscribe to Optional Parameters: ack - how to handle acknowledgements for a message; either automatically (auto) or manually (client) Description: Register to listen to a given destination. Like send, the subscribe command requires a destination header indicating which destination to subscribe to. The ack parameter is optional, and defaults to auto. ''' if len(args) < 2: print 'expecting: subscribe <destination> [ack]' elif len(args) > 2: print 'subscribing to "%s" with acknowledge set to "%s"' % (args[1], args[2]) self.c.subscribe(destination=args[1], ack=args[2]) else: print 'subscribing to "%s" with auto acknowledge' % args[1] self.c.subscribe(destination=args[1], ack='auto') def unsubscribe(self, args): ''' Usage: unsubscribe <destination> Required Parameters: destination - the name to unsubscribe from Description: Remove an existing subscription - so that the client no longer receive messages from that destination. ''' if len(args) < 2: print 'expecting: unsubscribe <destination>' else: print 'unsubscribing from "%s"' % args[1] self.c.unsubscribe(destination=args[1]) def stats(self, args): ''' Usage: stats [on|off] Description: Record statistics on messages sent, received, errors, etc. If no argument (on|off) is specified, dump the current statistics. ''' if len(args) < 2: stats = self.c.get_listener('stats') if stats: print stats else: print 'No stats available' elif args[1] == 'on': self.c.set_listener('stats', StatsListener()) elif args[1] == 'off': self.c.remove_listener('stats') else: print 'expecting: stats [on|off]' def help(self, args): ''' Usage: help [command] Description: Display info on a specified command, or a list of available commands ''' if len(args) == 1: print 'Usage: help <command>, where command is one of the following:' print ' ' for f in dir(self): if f.startswith('_') or f.startswith('on_') or f == 'c': continue else: print '%s ' % f, print '' return elif not hasattr(self, args[1]): print 'There is no command "%s"' % args[1] return func = getattr(self, args[1]) if hasattr(func, '__doc__') and getattr(func, '__doc__') is not None: print func.__doc__ else: print 'There is no help for command "%s"' % args[1]