Source code for spinnman.connections.abstract_classes.udp_receivers.abstract_udp_sdp_receiver
from abc import ABCMeta
from abc import abstractmethod
from six import add_metaclass
import select
import socket
from spinnman.connections.abstract_classes.abstract_sdp_receiver import \
AbstractSDPReceiver
from spinnman.data.little_endian_byte_array_byte_reader import \
LittleEndianByteArrayByteReader
from spinnman.exceptions import SpinnmanTimeoutException, SpinnmanIOException, \
SpinnmanInvalidPacketException
from spinnman.messages.sdp.sdp_header import SDPHeader
from spinnman.messages.sdp.sdp_message import SDPMessage
@add_metaclass(ABCMeta)
[docs]class AbstractUDPSDPReceiver(AbstractSDPReceiver):
""" A receiver of SDP messages
"""
@abstractmethod
[docs] def is_udp_sdp_reciever(self):
pass
[docs] def receive_sdp_message(self, timeout=None):
""" Receives an SDP message from this connection. Blocks until the\
message has been received, or a timeout occurs.
:param timeout: The time in seconds to wait for the message to arrive;\
if not specified, will wait forever, or until the\
connection is closed
:type timeout: int
:return: The received SDP message
:rtype: :py:class:`spinnman.messages.sdp.sdp_message.SDPMessage`
:raise spinnman.exceptions.SpinnmanIOException: If there is an error\
receiving the message
:raise spinnman.exceptions.SpinnmanTimeoutException: If there is a\
timeout before a message is received
:raise spinnman.exceptions.SpinnmanInvalidPacketException: If the\
received packet is not a valid SDP message
:raise spinnman.exceptions.SpinnmanInvalidParameterException: If one of\
the fields of the SDP message is invalid
"""
# Receive the data
raw_data = None
try:
read_ready, _, _ = select.select([self._socket], [], [], timeout)
if not read_ready:
raise socket.timeout()
raw_data = self._socket.recv(512)
except socket.timeout:
raise SpinnmanTimeoutException("receive_sdp_message", timeout)
except Exception as e:
raise SpinnmanIOException(str(e))
# Set up for reading
packet = bytearray(raw_data)
reader = LittleEndianByteArrayByteReader(packet)
# Read the padding
try:
reader.read_short()
except EOFError:
raise SpinnmanInvalidPacketException(
"SDP", "Not enough bytes to read the pre-packet padding")
# Read the header and data
sdp_header = SDPHeader()
sdp_header.read_sdp_header(reader)
data = reader.read_bytes()
if len(data) == 0:
data = None
# Create and return the message
message = SDPMessage(sdp_header=sdp_header, data=data)
return message