Source code for

Contains handling of ASC logging files.

Example .asc files:
    - under `test/data/logfile.asc`

from typing import cast, Any, Generator, IO, List, Optional, Union, Dict
from can import typechecking

from datetime import datetime
import time
import logging

from ..message import Message
from ..listener import Listener
from ..util import channel2int
from .generic import BaseIOHandler

CAN_MSG_EXT = 0x80000000

logger = logging.getLogger("")

[docs]class ASCReader(BaseIOHandler): """ Iterator of CAN messages from a ASC logging file. Meta data (comments, bus statistics, J1939 Transport Protocol messages) is ignored. TODO: turn relative timestamps back to absolute form """ def __init__( self, file: Union[typechecking.FileLike, typechecking.StringPathLike], base: str = "hex", ) -> None: """ :param file: a path-like object or as file-like object to read from If this is a file-like object, is has to opened in text read mode, not binary read mode. :param base: Select the base(hex or dec) of id and data. If the header of the asc file contains base information, this value will be overwritten. Default "hex". """ super().__init__(file, mode="r") if not self.file: raise ValueError("The given file cannot be None") self.base = base self._converted_base = self._check_base(base) = None self.timestamps_format = None self.internal_events_logged = None def _extract_header(self): for line in self.file: line = line.strip() lower_case = line.lower() if lower_case.startswith("date"): = line[5:] elif lower_case.startswith("base"): try: _, base, _, timestamp_format = line.split() except ValueError: raise Exception("Unsupported header string format: {}".format(line)) self.base = base self._converted_base = self._check_base(self.base) self.timestamps_format = timestamp_format elif lower_case.endswith("internal events logged"): self.internal_events_logged = not lower_case.startswith("no") # Currently the last line in the header which is parsed break else: break def _extract_can_id(self, str_can_id: str, msg_kwargs: Dict[str, Any]) -> None: if str_can_id[-1:].lower() == "x": msg_kwargs["is_extended_id"] = True can_id = int(str_can_id[0:-1], self._converted_base) else: msg_kwargs["is_extended_id"] = False can_id = int(str_can_id, self._converted_base) msg_kwargs["arbitration_id"] = can_id @staticmethod def _check_base(base: str) -> int: if base not in ["hex", "dec"]: raise ValueError('base should be either "hex" or "dec"') return BASE_DEC if base == "dec" else BASE_HEX def _process_data_string( self, data_str: str, data_length: int, msg_kwargs: Dict[str, Any] ) -> None: frame = bytearray() data = data_str.split() for byte in data[:data_length]: frame.append(int(byte, self._converted_base)) msg_kwargs["data"] = frame def _process_classic_can_frame( self, line: str, msg_kwargs: Dict[str, Any] ) -> Message: # CAN error frame if line.strip()[0:10].lower() == "errorframe": # Error Frame msg_kwargs["is_error_frame"] = True else: abr_id_str, dir, rest_of_message = line.split(None, 2) msg_kwargs["is_rx"] = dir == "Rx" self._extract_can_id(abr_id_str, msg_kwargs) if rest_of_message[0].lower() == "r": # CAN Remote Frame msg_kwargs["is_remote_frame"] = True remote_data = rest_of_message.split() if len(remote_data) > 1: dlc_str = remote_data[1] if dlc_str.isdigit(): msg_kwargs["dlc"] = int(dlc_str, self._converted_base) else: # Classic CAN Message try: # There is data after DLC _, dlc_str, data = rest_of_message.split(None, 2) except ValueError: # No data after DLC _, dlc_str = rest_of_message.split(None, 1) data = "" dlc = int(dlc_str, self._converted_base) msg_kwargs["dlc"] = dlc self._process_data_string(data, dlc, msg_kwargs) return Message(**msg_kwargs) def _process_fd_can_frame(self, line: str, msg_kwargs: Dict[str, Any]) -> Message: channel, dir, rest_of_message = line.split(None, 2) # See ASCWriter msg_kwargs["channel"] = int(channel) - 1 msg_kwargs["is_rx"] = dir == "Rx" # CAN FD error frame if rest_of_message.strip()[:10].lower() == "errorframe": # Error Frame # TODO: maybe use regex to parse BRS, ESI, etc? msg_kwargs["is_error_frame"] = True else: can_id_str, frame_name_or_brs, rest_of_message = rest_of_message.split( None, 2 ) if frame_name_or_brs.isdigit(): brs = frame_name_or_brs esi, dlc_str, data_length_str, data = rest_of_message.split(None, 3) else: brs, esi, dlc_str, data_length_str, data = rest_of_message.split( None, 4 ) self._extract_can_id(can_id_str, msg_kwargs) msg_kwargs["bitrate_switch"] = brs == "1" msg_kwargs["error_state_indicator"] = esi == "1" dlc = int(dlc_str, self._converted_base) msg_kwargs["dlc"] = dlc data_length = int(data_length_str) # CAN remote Frame msg_kwargs["is_remote_frame"] = data_length == 0 self._process_data_string(data, data_length, msg_kwargs) return Message(**msg_kwargs) def __iter__(self) -> Generator[Message, None, None]: # This is guaranteed to not be None since we raise ValueError in __init__ self.file = cast(IO[Any], self.file) self._extract_header() for line in self.file: temp = line.strip() if not temp or not temp[0].isdigit(): # Could be a comment continue msg_kwargs = {} try: timestamp, channel, rest_of_message = temp.split(None, 2) timestamp = float(timestamp) msg_kwargs["timestamp"] = timestamp if channel == "CANFD": msg_kwargs["is_fd"] = True elif channel.isdigit(): # See ASCWriter msg_kwargs["channel"] = int(channel) - 1 else: # Not a CAN message. Possible values include "statistic", J1939TP continue except ValueError: # Some other unprocessed or unknown format continue if "is_fd" not in msg_kwargs: msg = self._process_classic_can_frame(rest_of_message, msg_kwargs) else: msg = self._process_fd_can_frame(rest_of_message, msg_kwargs) if msg is not None: yield msg self.stop()
[docs]class ASCWriter(BaseIOHandler, Listener): """Logs CAN data to an ASCII log file (.asc). The measurement starts with the timestamp of the first registered message. If a message has a timestamp smaller than the previous one or None, it gets assigned the timestamp that was written for the last message. It the first message does not have a timestamp, it is set to zero. """ FORMAT_MESSAGE = "{channel} {id:<15} {dir:<4} {dtype} {data}" FORMAT_MESSAGE_FD = " ".join( [ "CANFD", "{channel:>3}", "{dir:<4}", "{id:>8} {symbolic_name:>32}", "{brs}", "{esi}", "{dlc:x}", "{data_length:>2}", "{data}", "{message_duration:>8}", "{message_length:>4}", "{flags:>8X}", "{crc:>8}", "{bit_timing_conf_arb:>8}", "{bit_timing_conf_data:>8}", "{bit_timing_conf_ext_arb:>8}", "{bit_timing_conf_ext_data:>8}", ] ) FORMAT_START_OF_FILE_DATE = "%a %b %d %I:%M:%S.%f %p %Y" FORMAT_DATE = "%a %b %d %I:%M:%S.{} %p %Y" FORMAT_EVENT = "{timestamp: 9.6f} {message}\n" def __init__( self, file: Union[typechecking.FileLike, typechecking.StringPathLike], channel: int = 1, ) -> None: """ :param file: a path-like object or as file-like object to write to If this is a file-like object, is has to opened in text write mode, not binary write mode. :param channel: a default channel to use when the message does not have a channel set """ super().__init__(file, mode="w") if not self.file: raise ValueError("The given file cannot be None") = channel # write start of file header now = self.file.write("date %s\n" % now) self.file.write("base hex timestamps absolute\n") self.file.write("internal events logged\n") # the last part is written with the timestamp of the first message self.header_written = False self.last_timestamp = 0.0 self.started = 0.0
[docs] def stop(self) -> None: # This is guaranteed to not be None since we raise ValueError in __init__ self.file = cast(IO[Any], self.file) if not self.file.closed: self.file.write("End TriggerBlock\n") super().stop()
[docs] def log_event(self, message: str, timestamp: Optional[float] = None) -> None: """Add a message to the log file. :param message: an arbitrary message :param timestamp: the absolute timestamp of the event """ if not message: # if empty or None logger.debug("ASCWriter: ignoring empty message") return # This is guaranteed to not be None since we raise ValueError in __init__ self.file = cast(IO[Any], self.file) # this is the case for the very first message: if not self.header_written: self.last_timestamp = timestamp or 0.0 self.started = self.last_timestamp mlsec = repr(self.last_timestamp).split(".")[1][:3] formatted_date = time.strftime( self.FORMAT_DATE.format(mlsec), time.localtime(self.last_timestamp) ) self.file.write("Begin Triggerblock %s\n" % formatted_date) self.header_written = True self.log_event("Start of measurement") # caution: this is a recursive call! # Use last known timestamp if unknown if timestamp is None: timestamp = self.last_timestamp # turn into relative timestamps if necessary if timestamp >= self.started: timestamp -= self.started line = self.FORMAT_EVENT.format(timestamp=timestamp, message=message) self.file.write(line)
[docs] def on_message_received(self, msg: Message) -> None: if msg.is_error_frame: self.log_event("{} ErrorFrame".format(, msg.timestamp) return if msg.is_remote_frame: dtype = "r {:x}".format(msg.dlc) # New after v8.5 data: List[str] = [] else: dtype = "d {:x}".format(msg.dlc) data = ["{:02X}".format(byte) for byte in] arb_id = "{:X}".format(msg.arbitration_id) if msg.is_extended_id: arb_id += "x" channel = channel2int( if channel is None: channel = else: # Many interfaces start channel numbering at 0 which is invalid channel += 1 if msg.is_fd: flags = 0 flags |= 1 << 12 if msg.bitrate_switch: flags |= 1 << 13 if msg.error_state_indicator: flags |= 1 << 14 serialized = self.FORMAT_MESSAGE_FD.format( channel=channel, id=arb_id, dir="Rx" if msg.is_rx else "Tx", symbolic_name="", brs=1 if msg.bitrate_switch else 0, esi=1 if msg.error_state_indicator else 0, dlc=msg.dlc, data_length=len(data), data=" ".join(data), message_duration=0, message_length=0, flags=flags, crc=0, bit_timing_conf_arb=0, bit_timing_conf_data=0, bit_timing_conf_ext_arb=0, bit_timing_conf_ext_data=0, ) else: serialized = self.FORMAT_MESSAGE.format( channel=channel, id=arb_id, dir="Rx" if msg.is_rx else "Tx", dtype=dtype, data=" ".join(data), ) self.log_event(serialized, msg.timestamp)