def to_representation(self):
header = f"{constants.SOH}{self.command}{self.command_type}"
if self.data_set:
body = f"{constants.STX}{self.data_set.to_representation()}{constants.ETX}"
else:
body = f"{constants.ETX}"
message = f"{header}{body}"
return utils.add_bcc(message)
def to_representation(self):
if self.partial_blocks:
command = "R3"
rows_per_block = self.rows_per_block
else:
command = "R1"
rows_per_block = ""
rep = (
f"{constants.SOH}{command}{constants.STX}{self.archive}:V.{self.attribute}"
f"({self.position};{self.start};{self.end};{rows_per_block}){constants.ETX}"
)
return utils.add_bcc(rep)
def read(self, timeout=None):
"""
Will read a normal readout. Supports both full and partial block readout.
When using partial blocks it will recreate the messages as it was not sent with
partial blocks
:param timeout:
:return:
"""
start_chars = [b"\x01", b"\x02"]
end_chars = [b"\x03", b"\x04"]
total_data = b""
packets = 0
start_char_received = False
start_char = None
end_char = None
timeout = timeout or self.timeout
while True:
in_data = b""
duration = 0
start_time = time.time()
while True:
b = self.recv(1)
duration = time.time() - start_time
if duration > self.timeout:
raise TimeoutError(
f"Read in {self.__class__.__name__} timed out")
if b == b'\x15' or b == b'\x06':
in_data += b
logger.debug(
f"Received {in_data!r} over transport: {self.__class__.__name__}"
)
return in_data
if not start_char_received:
# is start char?
if b in start_chars:
in_data += b
start_char_received = True
start_char = b
continue
else:
continue
else:
# is end char?
if b in end_chars:
in_data += b
end_char = b
break
else:
in_data += b
continue
packets += 1
bcc = self.recv(1)
in_data += bcc
logger.debug(
f"Received {in_data!r} over transport: {self.__class__.__name__}"
)
if start_char == b"\x01":
# This is a command message, probably Password challange.
total_data += in_data
break
if end_char == b"\x04": # EOT (partial read)
# we received a partial block
if not utils.bcc_valid(in_data):
# Nack and read again
self.send(constants.NACK.encode(constants.ENCODING))
continue
else:
# ack and read next
self.send(constants.ACK.encode(constants.ENCODING))
# remove bcc and eot and add line end.
in_data = in_data[:-2] + constants.LINE_END.encode(
constants.ENCODING)
if packets > 1:
# remove the leading STX
in_data = in_data[1:]
total_data += in_data
continue
if end_char == b"\x03":
# Either it was the only message or we got the last message.
if not utils.bcc_valid(in_data):
# Nack and read again
self.send(constants.NACK.encode(constants.ENCODING))
continue
else:
if packets > 1:
in_data = in_data[1:] # removing the leading STX
total_data += in_data
if packets > 1:
# The last bcc is not correct compared to the whole
# message. But we have verified all the bccs along the way so
# we just compute it so the message is usable.
total_data = utils.add_bcc(total_data[:-1])
break
return total_data
def to_representation(self):
# TODO: this is not valid in case reading out partial blocks.
rep = f"{constants.STX}{self.data_block.to_representation()}{constants.ETX}"
return utils.add_bcc(rep)
def to_representation(self):
data = (
f"{constants.STX}{self.data_block.to_representation()}{constants.END_CHAR}"
f"{constants.LINE_END}{constants.ETX}")
return utils.add_bcc(data)
def test_add_bcc1(self):
data = "\x01P0\x02(1234567)\x03"
correct_data = "\x01P0\x02(1234567)\x03P"
with_bcc = add_bcc(data)
assert with_bcc == correct_data