class NatsClient(object):
'nats client class'
def __init__(self, **argvs):
self.subs = {}
self.buf = None
self.parse_state = Common.AWAITING_CONTROL_LINE
self.stat = Stat()
self.conn = Connector(callback=self.process_data, **argvs)
self.ping_timer = Heartbeat(self.conn)
print self.__str__()
def start(self):
'start nats client, open the connection, and start the ping timer;'
self.conn.open()
self.ping_timer.start()
def stop(self):
'stop the nats client, close the connection, and cancel ping timer;'
#self.conn.close()
try:
self.conn.close()
self.ping_timer.cancel()
except Exception, ex:
print 'error exit 1'
sys.exit(1)
class NatsClient(object):
'nats client class'
def __init__(self, **argvs):
self.subs = {}
self.buf = None
self.parse_state = Common.AWAITING_CONTROL_LINE
self.stat = Stat()
self.conn = Connector(callback=self.process_data, **argvs)
self.ping_timer = Heartbeat(self.conn)
print self.__str__()
def start(self):
'start nats client, open the connection, and start the ping timer;'
self.conn.open()
self.ping_timer.start()
def stop(self):
'stop the nats client, close the connection, and cancel ping timer;'
#self.conn.close()
try:
self.conn.close()
self.ping_timer.cancel()
except Exception, ex:
print 'error exit 1'
sys.exit(1)
def __init__(self, **argvs):
self.subs = {}
self.buf = None
self.parse_state = Common.AWAITING_CONTROL_LINE
self.stat = Stat()
self.conn = Connector(callback=self.process_data, **argvs)
self.ping_timer = Heartbeat(self.conn)
print self.__str__()
def __init__(self, **argvs):
self.subs = {}
self.buf = None
self.parse_state = Common.AWAITING_CONTROL_LINE
self.stat = Stat()
self.conn = Connector(callback=self.process_data, **argvs)
self.ping_timer = Heartbeat(self.conn)
print self.__str__()
class NatsClient(object):
'nats client class'
def __init__(self, **argvs):
self.subs = {}
self.buf = None
self.parse_state = Common.AWAITING_CONTROL_LINE
self.stat = Stat()
self.conn = Connector(callback=self.process_data, **argvs)
self.ping_timer = Heartbeat(self.conn)
print self.__str__()
def start(self):
'start nats client, open the connection, and start the ping timer;'
self.conn.open()
self.ping_timer.start()
def stop(self):
'stop the nats client, close the connection, and cancel ping timer;'
self.conn.close()
self.ping_timer.cancel()
def _on_messsage(self, subject, sid, msg, reply=None):
'''\
actions when received messages from nats server;
Params:
=====
subject: message subject;
sid: subscriber id;
reply: inbox name if exists
msg: message body
'''
self.stat.msgs_received += 1
if msg:
self.stat.bytes_received += len(msg)
if sid not in self.subs:
return
sub = self.subs[sid]
#unsubscribe subscriber if received enough messages;
sub["received"] += 1
if "max" in sub:
if sub["received"] > sub["max"]:
return self.unsubscribe(sid)
if sub["received"] == sub["max"]:
del self.subs[sid]
callback = sub["callback"]
if callback:
args, _, _, _ = inspect.getargspec(callback)
args_len = len(args)
if args_len == 0:
callback()
elif args_len == 1:
callback(msg)
elif args_len == 2:
callback(msg, reply)
else:
callback.call(msg, reply, subject)
# cancel autounscribe timer, if subscriber request with timeout,
# and receive enough messages;
if "timeout" in sub \
and sub["timeout"] \
and sub["received"] >= sub["expected"]:
sub["timeout"].cancel()
sub["timeout"] = None
self.subs[sid] = sub
def _process_info(self, info):
'''\
process server infomation message;
Params:
=====
info: nats server information
'''
server_info = json.loads(info)
print 'process info'
if server_info["auth_required"]:
conn_opts = self.conn.get_connection_options()
self.conn.send_command(Protocol.connect_command(conn_opts),
True)
def publish(self, subject, msg=Protocol.EMPTY_MSG, opt_reply="", blk=None):
'''\
Publish a message to a given subject, with optional reply subject and
completion block
Params:
=====
subject: message subject;
msg: message body;
opt_reply: reply inbox if needs;
blk: closure called when publish has been processed by the server.
'''
if not self.conn.connected:
raise NatsClientException("Connection losted")
if not subject:
return None
msg = str(msg)
self.stat.msgs_sent += 1
self.stat.bytes_sent += len(msg)
self.conn.send_command("PUB {} {} {}{}{}{}".format(subject,
opt_reply, len(msg), Protocol.CR_LF, msg, Protocol.CR_LF))
if blk:
self.ping_timer.queue_server_rt(blk)
def subscribe(self, subject, callback=None, **opts):
'''\
Subscribe to a subject with optional wildcards.
Messages will be delivered to the supplied callback.
Callback can take any number of the supplied arguments as defined by the
list: msg, reply, sub.
Params:
=====
subject: optionally with wilcards.
opts: optional options hash, e.g. "queue", "max".
callback, called when a message is delivered.
Returns:
=====
sid: Subject Identifier
Returns subscription id which can be passed to #unsubscribe.
'''
if not self.conn.connected:
raise NatsClientException("Connection losted")
if not subject:
return None
sid = Common.get_ssid()
queue_str = ""
sub = {"subject" : subject, "received" : 0}
sub["callback"] = callback
if "queue" in opts:
queue_str = sub["queue"] = opts["queue"]
if "max" in opts:
sub["max"] = opts["max"]
self.conn.send_command("SUB {} {} {}{}".format(subject, queue_str,
sid, Protocol.CR_LF))
self.subs[sid] = sub
# Setup server support for auto-unsubscribe
if "max" in opts:
self.unsubscribe(sid, opts["max"])
return sid
def unsubscribe(self, sid, opt_max=None):
'''\
Cancel a subscription.
Params:
=====
sid: Subject Identifier
opt_max: optional number of responses to receive
before auto-unsubscribing.
'''
if not self.conn.connected:
raise NatsClientException("Connection losted")
opt_max_str = ""
if opt_max:
opt_max_str = " " + str(opt_max)
self.conn.send_command("UNSUB {}{}{}".format(sid,
opt_max_str, Protocol.CR_LF))
if not sid in self.subs:
return None
sub = self.subs[sid]
sub["max"] = opt_max
if not (sub["max"] and (sub["received"] < sub["max"])):
del self.subs[sid]
def timeout(self, sid, timeout, callback=None, **opts):
'''\
Setup a timeout for receiving messages for the subscription.
Params:
=====
sid: Subject Identifier
timeout: integer in seconds
opts: options, :auto_unsubscribe(true), :expected(1)
'''
if not self.conn.connected:
raise NatsClientException("Connection losted")
if not sid in self.subs:
return None
sub = self.subs[sid]
auto_unsubscribe, expected = True, 1
if "auto_unsubscribe" in opts:
auto_unsubscribe = opts["auto_unsubscribe"]
if "expected" in opts:
expected = opts["expected"]
def pblock():
'closure block for timeout request'
if auto_unsubscribe:
self.unsubscribe(sid)
if callback:
callback(sid)
sub["timeout"] = Timer(timeout, pblock)
sub["timeout"].start()
sub["expected"] = expected
self.subs[sid] = sub
def request(self, subject, data=None, blk=None, **opts):
'''\
Send a request and have the response delivered to the supplied callback.
Params:
=====
subject: message subject;
msg: message payload;
callback: callback if any;
Returns:
=====
sid: Subject Identifier
'''
if not self.conn.connected:
raise NatsClientException("Connection losted")
if not subject:
return None
inbox = Common.create_inbox()
def process_reply(msg, reply):
'closure block of request'
args, _, _, _ = inspect.getargspec(blk)
args_len = len(args)
if args_len == 0:
blk()
elif args_len == 1:
blk(msg)
else:
blk(msg, reply)
sid = self.subscribe(inbox, process_reply, **opts)
self.publish(subject, data, inbox)
return sid
def process_data(self, data):
"process data received from nats server, disptch data to proper handles"
if not data:
return
if not self.buf:
self.buf = data
else:
self.buf += data
assert_protocol_type = Protocol.assert_protocol_type
not_matched = Protocol.not_matched
matched = Protocol.matched
while self.buf:
print "buf.{}".format(self.buf)
if self.parse_state == Common.AWAITING_CONTROL_LINE:
if assert_protocol_type(self.buf, 'msg'):
print "matched message"
sub, sid, _, reply, needed = matched('msg', self.buf)
self.buf = not_matched('msg', self.buf)
sid = int(sid)
needed = int(needed)
self.parse_state = Common.AWAITING_MSG_PAYLOAD
elif assert_protocol_type(self.buf, 'ok'):
self.buf = not_matched('ok', self.buf)
print "parseed ok"
elif assert_protocol_type(self.buf, 'err'):
self.buf = not_matched('err', self.buf)
print "Nats server error."
elif assert_protocol_type(self.buf, 'ping'):
self.ping_timer.on_ping_request()
self.buf = not_matched('ping', self.buf)
elif assert_protocol_type(self.buf, 'pong'):
print "process Pong"
self.buf = not_matched('pong', self.buf)
self.ping_timer.on_pong_response()
elif assert_protocol_type(self.buf, 'info'):
self._process_info(matched('info', self.buf))
self.buf = not_matched('info', self.buf)
elif assert_protocol_type(self.buf, 'unknown'):
self.buf = not_matched('ok', self.buf)
raise NatsException("Unknown protocol")
else:
return None
if self.buf and len(self.buf) == 0:
self.buf = None
if self.parse_state == Common.AWAITING_MSG_PAYLOAD:
if not (needed and
len(self.buf) >= (needed + Protocol.CR_LF_SIZE)):
return None
self._on_messsage(sub, sid, self.buf[0 : needed], reply)
cr_lf_size = Protocol.CR_LF_SIZE
self.buf = self.buf[(needed + cr_lf_size) : len(self.buf)]
sub = sid = reply = needed = None
self.parse_state = Common.AWAITING_CONTROL_LINE
if self.buf and len(self.buf) == 0:
self.buf = None
def __str__(self):
return "python-nats-{}".format(Common.VERSION)
