def parse(bitstream, payload_length):
control = Control.parse(bitstream)
payload_length = payload_length - 1 # subtract control byte
dialog_id = bitstream.read("uint:8")
payload_length = payload_length - 1
transaction_id = bitstream.read("uint:8")
payload_length = payload_length - 1
target_rx_level_i = None
if control.has_agc:
target_rx_level_i = bitstream.read("uint:8")
payload_length -= 1
tl = None
if control.has_tl:
tl = CT.parse(bitstream)
payload_length -= 1
te = None
if control.has_te:
te = CT.parse(bitstream)
payload_length -= 1
tc = None
# TODO currently we have no way to know if Tc is present or not
# Tc is present when control.is_ack_requested AND when we are requester,
# while responders copy this flag but do NOT provide a Tc.
# When parsing single frames without knowledge of dialogs we cannot determine this.
# We use control.is_dialog_start for now but this will break when we start supporting multiple transactions per dialog
if control.is_ack_requested and control.is_dialog_start:
tc = CT.parse(bitstream)
payload_length -= 1
ack_template = None
if control.is_ack_not_void:
transaction_id_start = bitstream.read("uint:8")
payload_length = payload_length - 1
transaction_id_stop = bitstream.read("uint:8")
payload_length = payload_length - 1
assert transaction_id_start == transaction_id, "Other case not implemented yet"
assert transaction_id_stop == transaction_id, "Other case not implemented yet"
# TODO ack bitmap (for when transaction_id_start != transaction_id)
ack_template = [transaction_id_start, transaction_id_stop]
assert control.is_ack_record_requested == False, "Not implemented yet"
assert control.is_ack_not_void == False, "Not implemented yet"
alp_command = AlpParser().parse(bitstream, payload_length)
return Frame(control=control,
dialog_id=dialog_id,
transaction_id=transaction_id,
agc_rx_level_i=target_rx_level_i,
tl=tl,
te=te,
tc=tc,
ack_template=ack_template,
alp_command=alp_command)
def test_parsing(self):
ctrl = Control.parse(ConstBitStream(bytes=[0x93]))
self.assertEqual(ctrl.is_dialog_start, True)
self.assertEqual(ctrl.has_tl, False)
self.assertEqual(ctrl.has_te, True)
self.assertEqual(ctrl.is_ack_requested, False)
self.assertEqual(ctrl.is_ack_not_void, False)
self.assertEqual(ctrl.is_ack_record_requested, True)
self.assertEqual(ctrl.has_agc, True)
def test_byte_generation(self):
ctrl = Control(is_dialog_start=True,
has_tl=True,
has_te=False,
is_ack_requested=True,
is_ack_not_void=True,
is_ack_record_requested=False,
has_agc=False)
data = bytearray(ctrl)
self.assertEqual(len(data), 1)
self.assertEqual(data[0], 0xAC)
def parse(self, bitstream, payload_length):
is_dialog_start = bitstream.read("bool")
is_dialog_end = bitstream.read("bool")
_ = bitstream.read("pad:2"),
is_ack_return_template_requested = bitstream.read("bool")
is_ack_not_void = bitstream.read("bool")
is_ack_recorded = bitstream.read("bool")
_ = bitstream.read("pad:1")
payload_length = payload_length - 1 # subtract control byte
control = Control(is_dialog_start, is_dialog_end,
is_ack_return_template_requested, is_ack_not_void,
is_ack_recorded)
dialog_id = bitstream.read("uint:8")
payload_length = payload_length - 1
transaction_id = bitstream.read("uint:8")
payload_length = payload_length - 1
ack_template = None
if is_ack_not_void:
transaction_id_start = bitstream.read("uint:8")
payload_length = payload_length - 1
transaction_id_stop = bitstream.read("uint:8")
payload_length = payload_length - 1
assert transaction_id_start == transaction_id, "Other case not implemented yet"
assert transaction_id_stop == transaction_id, "Other case not implemented yet"
# TODO ack bitmap (for when transaction_id_start != transaction_id)
ack_template = [transaction_id_start, transaction_id_stop]
assert is_ack_recorded == False, "Not implemented yet"
assert is_ack_not_void == False, "Not implemented yet"
alp_command = AlpParser().parse(bitstream, payload_length)
return Frame(control=control,
dialog_id=dialog_id,
transaction_id=transaction_id,
ack_template=ack_template,
alp_command=alp_command)