def _marshal(self, pieces):
"""Create the full AMQP wire protocol frame data representation
:rtype: bytes
"""
payload = b''.join(pieces)
return struct.pack('>BHI', self.frame_type, self.channel_number,
len(payload)) + payload + byte(spec.FRAME_END)
def decode_frame(data_in):
"""Receives raw socket data and attempts to turn it into a frame.
Returns bytes used to make the frame and the frame
:param str data_in: The raw data stream
:rtype: tuple(bytes consumed, frame)
:raises: pika.exceptions.InvalidFrameError
"""
# Look to see if it's a protocol header frame
try:
if data_in[0:4] == b'AMQP':
major, minor, revision = struct.unpack_from('BBB', data_in, 5)
return 8, ProtocolHeader(major, minor, revision)
except (IndexError, struct.error):
return 0, None
# Get the Frame Type, Channel Number and Frame Size
try:
(frame_type, channel_number,
frame_size) = struct.unpack('>BHL', data_in[0:7])
except struct.error:
return 0, None
# Get the frame data
frame_end = spec.FRAME_HEADER_SIZE + frame_size + spec.FRAME_END_SIZE
# We don't have all of the frame yet
if frame_end > len(data_in):
return 0, None
# The Frame termination chr is wrong
if data_in[frame_end - 1:frame_end] != byte(spec.FRAME_END):
raise exceptions.InvalidFrameError("Invalid FRAME_END marker")
# Get the raw frame data
frame_data = data_in[spec.FRAME_HEADER_SIZE:frame_end - 1]
if frame_type == spec.FRAME_METHOD:
# Get the Method ID from the frame data
method_id = struct.unpack_from('>I', frame_data)[0]
# Get a Method object for this method_id
method = spec.methods[method_id]()
# Decode the content
method.decode(frame_data, 4)
# Return the amount of data consumed and the Method object
return frame_end, Method(channel_number, method)
elif frame_type == spec.FRAME_HEADER:
# Return the header class and body size
class_id, weight, body_size = struct.unpack_from('>HHQ', frame_data)
# Get the Properties type
properties = spec.props[class_id]()
# Decode the properties
out = properties.decode(frame_data[12:])
# Return a Header frame
return frame_end, Header(channel_number, body_size, properties)
elif frame_type == spec.FRAME_BODY:
# Return the amount of data consumed and the Body frame w/ data
return frame_end, Body(channel_number, frame_data)
elif frame_type == spec.FRAME_HEARTBEAT:
# Return the amount of data and a Heartbeat frame
return frame_end, Heartbeat()
raise exceptions.InvalidFrameError("Unknown frame type: %i" % frame_type)
