class MethodReader(object):
"""
Helper class to receive frames from the broker, combine them if
necessary with content-headers and content-bodies into complete methods.
Normally a method is represented as a tuple containing
(channel, method_sig, args, content).
In the case of a framing error, an AMQPConnectionException is placed
in the queue.
In the case of unexpected frames, a tuple made up of
(channel, AMQPChannelException) is placed in the queue.
"""
def __init__(self, source):
self.source = source
self.queue = Queue()
self.running = False
self.partial_messages = {}
# For each channel, which type is expected next
self.expected_types = defaultdict(lambda:1)
def _next_method(self, timeout=None):
"""
Read the next method from the source, once one complete method has
been assembled it is placed in the internal queue.
"""
while self.queue.empty():
try:
frame_type, channel, payload = self.source.read_frame(timeout)
except Timeout:
# Ok, let pass it through
raise
except Exception, e:
#
# Connection was closed? Framing Error?
#
self.queue.put(e)
break
if self.expected_types[channel] != frame_type:
self.queue.put((
channel,
Exception('Received frame type %s while expecting type: %s' %
(frame_type, self.expected_types[channel])
)
))
elif frame_type == 1:
self._process_method_frame(channel, payload)
elif frame_type == 2:
self._process_content_header(channel, payload)
elif frame_type == 3:
self._process_content_body(channel, payload)
def __init__(self, source):
self.source = source
self.queue = Queue()
self.running = False
self.partial_messages = {}
# For each channel, which type is expected next
self.expected_types = defaultdict(lambda:1)
