def read_message(self, verbose=False):
"""Read new message
:param bool verbose: Log every dlt_message_read(). Set True only for debugging.
:returns: A new DLTMessage on successful read, None otherwise
:rtype: DLTMessage|None
"""
msg = DLTMessage(verbose=verbose)
res = dltlib.dlt_message_read(
ctypes.byref(msg),
ctypes.cast(self.receiver.buf, ctypes.POINTER(ctypes.c_uint8)),
ctypes.c_uint(self.receiver.bytesRcvd), # length
ctypes.c_int(0), # resync
ctypes.c_int(verbose)) # verbose
if res != DLT_MESSAGE_ERROR_OK:
# - failed to read a complete message, possibly read an incomplete
# message
return None
# prepare storage header
if msg.standardheader.htyp & DLT_HTYP_WEID:
dltlib.dlt_set_storageheader(msg.p_storageheader,
msg.headerextra.ecu)
else:
dltlib.dlt_set_storageheader(msg.p_storageheader,
ctypes.c_char_p(""))
return msg
def from_bytes(data):
"""Create a class instance from a byte string in DLT storage format"""
msg = DLTMessage()
storageheader, remainder = msg.extract_storageheader(data)
buf = ctypes.create_string_buffer(remainder)
dltlib.dlt_message_read(ctypes.byref(msg),
ctypes.cast(buf, ctypes.POINTER(ctypes.c_uint8)),
ctypes.c_uint(len(remainder)),
0, # resync
0) # verbose
msg.p_storageheader.contents = storageheader
msg.initialized_as_object = False
return msg