def __init__(self, settings, lock=None):
self.settings = settings
self.lock = lock or threading.RLock()
self.exclusive = threading.RLock()
self.codec = Codec()
# Setup asynchronous frame receiving.
self.frames = queue.Queue()
self.thread = threading.Thread(target=self.__main__)
self.thread.daemon = True
# Keep track of ingress and egress data for heartbeating.
self.data_in = collections.deque([], 10)
self.data_out = collections.deque([], 10)
self._must_stop = False
self._observers = []
self._error = None
self._max_retries = 10
self._receipt_timeout = 1000
self._receipts = ReceiptManager(self)
class Connection(object):
"""Manages the connection to the ``STOMP`` server."""
buf_size = 1024
DiscardFrame = type('DiscardFrame', (Exception,), {})
EVNT_FRAME_RECV = 'frame_received'
EVNT_FRAME_SENT = 'frame_sent'
EVNT_RECONNECT = 'reconnect'
@staticmethod
def get_connect_frame(settings):
headers = {
'accept-version': ACCEPT_VERSIONS,
'host': settings.vhost,
'login': settings.username,
'passcode': settings.password
}
if settings.send_hb or settings.send_hb:
headers.update({
'heart-beat': "{send_hb},{recv_hb}".format(
send_hb=settings.send_hb,
recv_hb=settings.recv_hb
)
})
return ConnectFrame(list(headers.items()))
@property
def message_factory(self):
return self.settings.message_factory
def __init__(self, settings, lock=None):
self.settings = settings
self.lock = lock or threading.RLock()
self.exclusive = threading.RLock()
self.codec = Codec()
# Setup asynchronous frame receiving.
self.frames = queue.Queue()
self.thread = threading.Thread(target=self.__main__)
self.thread.daemon = True
# Keep track of ingress and egress data for heartbeating.
self.data_in = collections.deque([], 10)
self.data_out = collections.deque([], 10)
self._must_stop = False
self._observers = []
self._error = None
self._max_retries = 10
self._receipt_timeout = 1000
self._receipts = ReceiptManager(self)
def claim(self):
"""Return a context-manager that exclusively claims all I/O
for this :class:`Connection`.
"""
return self.lock
def join_destination(self, destinations):
"""Joins a list of destination using the destination separator
specified in the configuration.
"""
return self.settings.dest_separator.join(destinations)\
if isinstance(destinations, (list, tuple))\
else destinations
def split_destinations(self, destinations):
return destinations.split(self.settings.dest_separator)
def register_observer(self, observer):
if observer not in self._observers:
self._observers.append(observer)
def notify_observers(self, event, **kwargs):
for observer in self._observers:
observer.notify(event, **kwargs)
def must_heartbeat(self):
"""Return a boolean indicating if the client must send a heartbeat
to the ``STOMP`` server.
"""
hb = False
if self.data_out:
delta_t = int(time.time() * 1000) - self.data_out[-1]
hb |= delta_t > self.settings.send_hb
return hb
def connect(self):
"""Connect the :class:`Connection` instance to the remote
``STOMP`` server.
"""
self._connect_socket()
self.send_frame(self.get_connect_frame(self.settings))
self.thread.start()
response = self.recv_frame(True, 2500)
return Session.fromframe(self, response)
def update(self):
"""Read all data from the socket and add the frames to the frame
buffer.
"""
with self.lock:
octet_count = 0
buf = io.BytesIO()
while True:
# Note: this approach assumes that the server always
# sends us complete frames.
try:
buf.write(self.recv(self.buf_size))
except EnvironmentError as e:
if e.errno != errno.EAGAIN: raise
break
buf.seek(0)
# Continue to the next iteration if there are no
# octets to read.
for frame in self.codec.consume_buffer(buf):
if frame.is_error():
raise StompException.fromframe(frame)
try:
self.notify_observers(self.EVNT_FRAME_RECV, frame=frame)
except self.DiscardFrame:
pass
self.frames.put(frame)
def send_frame(self, frame):
"""Sends a ``STOMP`` frame, represented as a :class:`
~stomp.frames.Frame` instance, to the remote server.
"""
self.notify_observers(self.EVNT_FRAME_SENT, frame=frame)
raw = self.codec.encode(*frame, encode=True)
attempts = 0
#print(raw)
while True:
result = self.send(raw)
if not frame.expects_receipt():
break
try:
self._receipts.wait(frame.receipt_id, self._receipt_timeout)
break
except FrameNotConfirmed:
attempts += 1
if attempts > self._max_retries:
raise
return result
def send(self, seq):
"""Send a byte-sequence to the remote server."""
with self.lock:
#if len(seq) > 1:
# print(seq)
self.data_out.append(int(time.time() * 1000))
return self.socket.send(seq)
def recv(self, n):
"""Receive at maximum ``n`` amount of bytes from the server."""
with self.lock:
seq = self.socket.recv(n)
if seq:
self.data_in.append(int(time.time() * 1000))
#print(seq)
return seq
def recv_frame(self, block=True, timeout=None):
"""Receive one frame from the ``STOMP`` server."""
if timeout:
timeout = int(timeout / 1000)
try:
frame = self.frames.get(block, timeout)
self.frames.task_done()
finally:
if self._error:
raise self._error
return frame
def close(self):
"""Sends the ``DISCONNECT`` frame to the ``STOMP``
server and closes the socket.
"""
with self.lock:
self.send_frame(DisconnectFrame())
self._close_connection()
def _connect_socket(self):
# TODO: IPv6 support!!!!!!!!!
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.socket.connect((self.settings.host, self.settings.port))
self.socket.setblocking(0)
def _close_connection(self):
self._stop()
self.socket.close()
def _stop(self):
self._must_stop = True
def _is_stopped(self):
return self._must_stop
def __main__(self):
# A main event loop draining data from the socket and putting it
# in a buffer.
self._must_stop = False
while True:
if self._is_stopped():
break
with self.lock:
# Send a newline to satisfy the servers' heartbeat
# expectations, if necessary.
if self.must_heartbeat():
self.send('\n'.encode())
try:
self.update()
except StompException as e:
self._close_connection()
self._error = e
time.sleep(0.02)
