Source code for spinnman.connections.abstract_classes.udp_receivers.abstract_udp_scp_receiver
from abc import ABCMeta
from abc import abstractmethod
from six import add_metaclass
import select
import socket
from spinnman.connections.abstract_classes.abstract_scp_receiver import \
AbstractSCPReceiver
from spinnman.data.little_endian_byte_array_byte_reader import \
LittleEndianByteArrayByteReader
from spinnman.exceptions import SpinnmanTimeoutException, SpinnmanIOException, \
SpinnmanInvalidPacketException
@add_metaclass(ABCMeta)
[docs]class AbstractUDPSCPReceiver(AbstractSCPReceiver):
""" A receiver of SCP messages
"""
@abstractmethod
[docs] def is_udp_scp_receiver(self):
pass
[docs] def receive_scp_response(self, scp_response, timeout=None):
""" Receives an SCP message from this connection. Blocks\
until a message has been received, or a timeout occurs.
:param scp_response: The response to fill in
:rtype scp_response:\
:py:class:`spinnman.messages.scp.abstract_scp_response.AbstractSCPResponse`
: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: Nothing is returned
:rtype: None
: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 SCP message
:raise spinnman.exceptions.SpinnmanInvalidParameterException: If one\
of the fields of the SCP message is invalid
"""
# Receive the data
raw_data = None
try:
ready_read, _, _ = select.select([self._socket], [], [], timeout)
if not ready_read:
raise socket.timeout()
raw_data = self._socket.recv(512)
except socket.timeout:
raise SpinnmanTimeoutException("receive_scp_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(
"SCP", "Not enough bytes to read the pre-packet padding")
# Read the response
scp_response.read_scp_response(reader)