canlogfilter.py

import re
import argparse
from collections import namedtuple


class Record:
    def __init__(self, crtime=0.00000, ch=1, hexid=0x000, dir="Rx", stat="d", data=None, length=0, bitcount=0, decid=0):
        self.crtime = crtime
        self.ch = ch
        self.hexid = hexid
        self.dir = dir
        self.stat = stat
        self.data = data or []
        self.length = length
        self.bitcount = bitcount
        self.decid = decid

    @property
    def dlc(self):
        return len(self.data)

    @classmethod
    def parse_from_file(cls, input_file):
        """
        The log format is fixed header fields, variable length data, ordered key-value pairs
        header fields: crtime, ch, hexid, dir, stat, dlc
        variable data: byte * dlc
        """
        HEADER_TYPES = (
            ('crtime', float),
            ('ch', int),
            ('hexid', lambda s: int(s, 16)),
            ('dir', str),
            ('stat', str),
            ('dlc', int),
        )
        HEADER_LENGTH = len(HEADER_TYPES)
        Header = namedtuple("Header", [field for field, _ in HEADER_TYPES])

        for line in input_file:
            fields = line.split()
            if not re.match("1|2", fields[1]):
                # ignore non-data rows
                continue

            # extract header
            header_values = fields[:HEADER_LENGTH]
            header_values = [func(value) for (field, func), value in zip(HEADER_TYPES, header_values)]
            header = Header(*header_values)

            # extract data
            data = map(lambda x: int(x, 16), fields[HEADER_LENGTH:][:header.dlc])

            # extract trailer
            length = fields[-7]
            bitcount = fields[-4]
            decid = fields[-1]

            yield cls(
                crtime=header.crtime,
                ch=header.ch,
                hexid=header.hexid,
                dir=header.dir,
                stat=header.stat,
                data=data,
                length=length,
                bitcount=bitcount,
                decid=decid
            )

    def __str__(self):
        return '%f %d %03X %s %d %s' % (
            self.crtime, self.ch, self.hexid, self.dir, self.dlc,
            ' '.join(["%02X" % byte for byte in self.data])
        )


def main():
    parser = argparse.ArgumentParser(description='CanlogFilter')

    parser.add_argument('inputFile', help='Input file path')
    parser.add_argument('--difftime', '-d', action='store_const', const=True, default=False, help='Print with difftime')

    group = parser.add_mutually_exclusive_group()
    group.add_argument('--pickup', '-u', nargs='*', type=lambda x: int(x, 16), help='pick up records')
    group.add_argument('--dropoff', '-o', nargs='*', type=lambda x: int(x, 16), help='drop off records')

    args = parser.parse_args()

    with open(args.inputFile) as input_file:
        canlog = Record.parse_from_file(input_file)

        if args.pickup:
            canlog = pick_log(canlog, args.pickup)
        elif args.dropoff:
            canlog = drop_log(canlog, args.dropoff)

        if args.difftime:
            printlog_with_diff_time(canlog)
        else:
            printlog(canlog)


def pick_log(canlog, ids):
    return filter(lambda rec: rec.hexid in ids, canlog)


def drop_log(canlog, ids):
    return filter(lambda rec: rec.hexid not in ids, canlog)


def printlog(canlog):
    for rec in canlog:
        print rec


def printlog_with_diff_time(canlog):
    prevtime = 0
    for rec in canlog:
        difftime = rec.crtime - prevtime
        print '%f %s' % (difftime, rec)
        prevtime = rec.crtime


if __name__ == '__main__': main()

48行目はPython2でしか動かない。Python3では入れ子のタプルの展開ができなくなったため。