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"))
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(cls, source_bytes: bytes):
data = bytearray(source_bytes)
tag = data.pop(0)
if tag != cls.TAG:
raise ValueError(
f"Tag {tag} is not correct for ActionResponse. Should be {cls.TAG}"
)
action_type = enumerations.ActionType(data.pop(0))
if action_type != enumerations.ActionType.NORMAL:
raise ValueError(
f"Bytes are not representing a ActionResponseNormal. Action type "
f"is {action_type}")
invoke_id_and_priority = InvokeIdAndPriority.from_bytes(
data.pop(0).to_bytes(1, "big"))
status = enumerations.ActionResultStatus(data.pop(0))
has_data = bool(data.pop(0))
if has_data:
data_is_error = data.pop(0) == 1
if not data_is_error:
raise ValueError(
"Data is not a ActionResponseNormalWithError, maybe a "
"ActionResponseNormal")
assert len(data) == 1
error = enumerations.DataAccessResult(data.pop(0))
else:
raise ValueError("No error data in ActionResponseWithError")
return cls(invoke_id_and_priority=invoke_id_and_priority,
status=status,
error=error)
def parse_list_response(source_bytes: bytes, amount: int):
data = bytearray(source_bytes)
dlms_data_items = list()
for index in range(0, amount):
answer_selection = data.pop(0)
if answer_selection == 0:
# DLMS data
parser = dlms_data.DlmsDataParser()
obj = parser.parse(data, limit=1)
rest = parser.get_buffer_tail()
dlms_data_items.append(obj[0])
data = rest
elif answer_selection == 1:
# Data Access Result
dlms_data_items.append(enums.DataAccessResult(data.pop(0)))
else:
raise ValueError("Not a valid answer selection byte")
return dlms_data_items
def from_bytes(cls, source_bytes: bytes):
data = bytearray(source_bytes)
tag = data.pop(0)
if tag != cls.TAG:
raise ValueError(
f"Tag for SetResponse is not correct. Got {tag}, should be {cls.TAG}"
)
type_choice = enums.SetResponseType(data.pop(0))
if type_choice is not enums.SetResponseType.NORMAL:
raise ValueError(
"The type of the SetResponse is not for a SetResponseNormal"
)
invoke_id_and_priority = InvokeIdAndPriority.from_bytes(
data.pop(0).to_bytes(1, "big")
)
result = enums.DataAccessResult(data.pop(0))
return cls(result=result, invoke_id_and_priority=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"))
choice = data.pop(0)
if choice != 1:
raise ValueError(
f"The data choice is not 1 to indicate error but: {choice}")
error = enums.DataAccessResult(data.pop(0))
return cls(error, invoke_id_and_priority)