def extract_sort_data(data):
"""Extract timestamp, message length, apid, ctid from a bytestring in DLT storage format (speed optimized)"""
htyp_data = ord(chr(data[16])) if six.PY3 else ord(data[16])
len_data = data[19:17:-1]
len_value = ctypes.cast(len_data, ctypes.POINTER(
ctypes.c_ushort)).contents.value + 16
apid = b""
ctid = b""
tmsp_value = 0.0
bytes_offset = 0 # We know where data will be in the message, but ...
if not htyp_data & DLT_HTYP_WEID: # if there is no ECU ID and/or Session ID, then it will be earlier
bytes_offset -= 4
if not htyp_data & DLT_HTYP_WSID:
bytes_offset -= 4
if htyp_data & DLT_HTYP_WTMS:
tmsp_base = 31 + bytes_offset # Typical timestamp end offset
tmsp_data = data[tmsp_base:tmsp_base - 4:-1]
tmsp_value = ctypes.cast(tmsp_data, ctypes.POINTER(
ctypes.c_uint32)).contents.value / 10000.0
if htyp_data & DLT_HTYP_UEH:
apid_base = 38 + bytes_offset # Typical APID end offset
apid = data[apid_base - 4:apid_base].rstrip(b"\x00")
ctid = data[apid_base:apid_base + 4].rstrip(b"\x00")
apid = bytes_to_str(apid)
ctid = bytes_to_str(ctid)
return tmsp_value, len_value, apid, ctid
def payload_decoded(self): # pylint: disable=invalid-overridden-method
"""Get the payload string
:returns: Payload string
:rtype: str
"""
return bytes_to_str(super(DLTMessage, self).payload_decoded)
def ecuid(self): # pylint: disable=invalid-overridden-method
"""Get the ECU ID
:returns: ECU ID
:rtype: str
"""
return bytes_to_str(self.storageheader.ecu or self.headerextra.ecu)
def ctid(self): # pylint: disable=invalid-overridden-method
"""Get the Context ID
:returns: Context ID
:rtype: str
"""
return bytes_to_str(
self.extendedheader.ctid if self.extendedheader else "")
def apid(self): # pylint: disable=invalid-overridden-method
"""Get the Application ID
:returns: Application ID
:rtype: str
"""
return bytes_to_str(
self.extendedheader.apid if self.extendedheader else "")
def __str__(self):
"""Construct DLTViewer-like string"""
out = [time.asctime(time.gmtime(self.storage_timestamp))]
if self.headerextra:
out.append(self.headerextra.tmsp / 10000.0)
out += [self.standardheader.mcnt, self.storageheader.ecu]
if self.extendedheader:
out += [self.extendedheader.apid, self.extendedheader.ctid]
if self.headerextra:
out.append(self.headerextra.seid)
out += [
self.type_string, self.subtype_string, self.mode_string, self.noar,
self.payload_decoded
]
return " ".join(bytes_to_str(item) for item in out)
