def _validate(cls, message: bytes, header: bytes,
length: int) -> base.Message:
# consistency check: bug in message singnature
assert len(header) == 5, f"wrong header length {len(header)}"
assert header[:2] == b"\x7E\x00", f"wrong header start {header!r}"
assert length in [7, 47], f"wrong payload length {length} != 4||47"
len_payload = header[-1]
assert length == len_payload + 7, f"wrong payload length {length} != {len_payload+7}"
# validate message: recoverable errors (throw away observation)
msg = cls(message)
if msg.header != header:
raise WrongMessageFormat(f"message header: {msg.header!r}")
if msg.tail != 0x7E:
raise WrongMessageFormat(f"message tail: {msg.tail:#x}")
if len(message) != length:
raise WrongMessageFormat(
f"message length: {len(message)} != {length}")
checksum = 0xFF - (sum(msg.header[1:]) + sum(msg.payload)) % 0x100
if msg.checksum != checksum:
raise WrongMessageChecksum(
f"message checksum {msg.checksum} != {checksum}")
if sum(msg.payload) == 0:
raise SensorWarmingUp(f"message empty: warming up sensor")
return msg
def decode(cls, message: bytes, command: base.Cmd) -> Tuple[float, ...]:
# decode ACK message
if command.answer_header == b"\xA5\xA5" and command.answer_length == 2:
if not message.endswith(command.answer_header):
raise WrongMessageFormat("message does not end in ACK")
return tuple()
return super().decode(message, command)
def _validate(cls, message: bytes, header: bytes, length: int) -> base.Message:
# consistency check: bug in message singnature
assert len(header) == 3, f"wrong header length {len(header)}"
assert header[:1] == b"\x40", f"wrong header start {header!r}"
assert length in [8, 16], f"wrong payload length {length}"
# validate message: recoverable errors (throw away observation)
msg = cls(message)
if msg.header != header:
raise WrongMessageFormat(f"message header: {msg.header!r}")
if len(message) != length:
raise WrongMessageFormat(f"message length: {len(message)} != {length}")
checksum = (0x10000 - sum(msg.header) - sum(msg.payload)) % 0x100
if msg.checksum != checksum:
raise WrongMessageChecksum(f"message checksum {msg.checksum} != {checksum}")
if sum(msg.payload) == 0:
raise SensorWarmingUp(f"message empty: warming up sensor")
return msg
def _validate(cls, message: bytes, header: bytes,
length: int) -> base.Message:
# consistency check: bug in message singnature
assert len(header) == 2, f"wrong header length {len(header)}"
# validate message: recoverable errors (throw away observation)
msg = cls(message)
if msg.header != header:
raise WrongMessageFormat(f"message header: {msg.header!r}")
if len(message) != length:
raise WrongMessageFormat(f"message length: {len(message)}")
checksum = message[-1]
if msg.checksum != checksum:
raise WrongMessageChecksum(
f"message checksum 0x{msg.checksum:02X} != 0x{checksum:02X}")
if sum(msg.payload) == 0:
raise SensorWarmingUp(f"message empty: warming up sensor")
return msg
def _validate(cls, message: bytes, header: bytes, length: int) -> base.Message:
# consistency check: bug in message singnature
assert len(header) == 4, f"wrong header length {len(header)}"
assert header[:2] == b"BM", f"wrong header start {header!r}"
len_payload = cls._unpack(header[-2:])[0]
assert length == 4 + len_payload, f"wrong payload length {length} != {4+len_payload}"
# validate message: recoverable errors (throw away observation)
msg = cls(message)
if msg.header != header:
raise WrongMessageFormat(f"message header: {msg.header!r}")
if len(message) != length:
raise WrongMessageFormat(f"message length: {len(message)}")
checksum = sum(msg.header) + sum(msg.payload)
if msg.checksum != checksum:
raise WrongMessageChecksum(f"message checksum {msg.checksum} != {checksum}")
if sum(msg.payload) == 0:
raise SensorWarmingUp(f"message empty: warming up sensor")
return msg