def from_bytes(cls, source_bytes: bytes):
data = bytearray(source_bytes)
tag = data.pop(0)
if tag != cls.TAG:
raise ValueError(
f"Tag is not correct. Should be {cls.TAG} but is {tag}")
response_type = enums.GetResponseType(data.pop(0))
if response_type != cls.RESPONSE_TYPE:
raise ValueError(
f"The response type byte: {response_type} is not for a GetResponseNormal"
)
invoke_id_and_priority = InvokeIdAndPriority.from_bytes(
data.pop(0).to_bytes(1, "big"))
last_block = bool(data.pop(0))
if not last_block:
raise ValueError(
f"Last block is not set to true in a GetResponseLastBlock.")
block_number = int.from_bytes(data[:4], "big")
data = data[4:]
choice = data.pop(0)
if choice != 0:
raise ValueError(
f"The data choice is not 0 to indicate data but: {choice}")
data_length, data = dlms_cosem.dlms_data.decode_variable_integer(data)
if data_length != len(data):
raise ValueError(
"The octet string in block data is not of the correct length")
return cls(bytes(data), block_number, invoke_id_and_priority)
def from_bytes(cls, source_bytes: bytes):
data = bytearray(source_bytes)
tag = data.pop(0)
if tag != cls.TAG:
raise ValueError(
f"Tag is not correct. Should be {cls.TAG} but is {tag}")
response_type = enums.GetResponseType(data.pop(0))
if response_type != cls.RESPONSE_TYPE:
raise ValueError(
f"The response type byte: {response_type} is not for a GetResponseNormal"
)
invoke_id_and_priority = InvokeIdAndPriority.from_bytes(
data.pop(0).to_bytes(1, "big"))
last_block = bool(data.pop(0))
if not last_block:
raise ValueError(
f"Last block is not set to true in a GetResponseLastBlock.")
block_number = int.from_bytes(data[:4], "big")
data = data[4:]
choice = data.pop(0)
if choice != 1:
raise ValueError(
f"The data choice is not 1 to indicate error but: {choice}")
assert len(data) == 1
error = enums.DataAccessResult(data.pop(0))
return cls(error, block_number, invoke_id_and_priority)
def from_bytes(source_bytes: bytes):
data = bytearray(source_bytes)
tag = data.pop(0)
if tag != GetResponseFactory.TAG:
raise ValueError(
f"Tag is not correct. Should be {GetResponseFactory.TAG} but is {tag}"
)
response_type = enums.GetResponseType(data.pop(0))
invoke_id_and_priority = InvokeIdAndPriority.from_bytes(
data.pop(0).to_bytes(1, "big"))
if response_type == enums.GetResponseType.NORMAL:
# check if it is an error or data response by assesing the choice.
choice = data.pop(0)
if choice == 0:
return GetResponseNormal(
invoke_id_and_priority=invoke_id_and_priority,
data=bytes(data))
elif choice == 1:
assert len(data) == 1 # should only be one byte left.
error = enums.DataAccessResult(data.pop(0))
return GetResponseNormalWithError(
invoke_id_and_priority=invoke_id_and_priority, error=error)
elif response_type == enums.GetResponseType.WITH_BLOCK:
last_block = bool(data.pop(0))
block_number = int.from_bytes(data[:4], "big")
data = data[4:]
choice = data.pop(0)
if choice == 0:
data_length, data = dlms_cosem.dlms_data.decode_variable_integer(
data)
if data_length != len(data):
raise ValueError(
"The octet string in block data is not of the correct length"
)
if last_block:
return GetResponseLastBlock(bytes(data), block_number,
invoke_id_and_priority)
else:
return GetResponseWithBlock(bytes(data), block_number,
invoke_id_and_priority)
elif choice == 1:
assert len(data) == 1 # should only be one byte left.
error = enums.DataAccessResult(data.pop(0))
if last_block:
return GetResponseLastBlockWithError(
error, block_number, invoke_id_and_priority)
else:
raise ValueError(
"It is not possible to send an error on a "
"GetResponseWithBlock. When an error occurs it "
"should always be sent in a GetResponseLastBlockWithError"
)
elif response_type == enums.GetResponseType.WITH_LIST:
return GetResponseWithList.from_bytes(bytes(source_bytes))
else:
raise ValueError("Response type is not a valid GetResponse type")
def from_bytes(cls, source_bytes: bytes):
data = bytearray(source_bytes)
tag = data.pop(0)
if tag != cls.TAG:
raise ValueError(
f"Tag is not correct. Should be {cls.TAG} but is {tag}")
response_type = enums.GetResponseType(data.pop(0))
if response_type != cls.RESPONSE_TYPE:
raise ValueError(
f"The response type byte: {response_type} is not for a GetResponseNormal"
)
invoke_id_and_priority = InvokeIdAndPriority.from_bytes(
data.pop(0).to_bytes(1, "big"))
choice = data.pop(0)
if choice != 0:
raise ValueError(
f"The data choice is not 0 to indicate data but: {choice}")
return cls(bytes(data), invoke_id_and_priority)