ASCReader: Skip J1939TP messages

[bessman]

.asc files can contain J1939 Transport Protocol messages, which look something like this:
0.297743 1 J1939TP FEE3p 6 0 0 - Rx d 23 A0 0F A6 60 3B D1 40 1F DE 80 25 DF C0 2B E1 00 4B FF FF 3C 0F 00 4B FF FF FF FF FF FF FF FF FF FF FF FF
This change makes ASCReader skip such messages, instead of breaking.

[codecov]

Codecov Report

Merging #701 into develop will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #701   +/-   ##
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  Coverage    68.34%   68.34%           
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  Files           69       69           
  Lines         6199     6199           
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  Hits          4237     4237           
  Misses        1962     1962

[christiansandberg]

Could you also add a line in test/data/logfile.asc?

[bessman]

Of course. In a real logfile the J1939TP entry would be preceded by a number of normal CAN messages containing parts of the J1939TP message. Should I also include those in the example file?

0.098426 1 18EBFF00x Rx d 8 01 A0 0F A6 60 3B D1 40 Length = 273910 BitCount = 141 ID = 418119424x 0.148421 1 18EBFF00x Rx d 8 02 1F DE 80 25 DF C0 2B Length = 271910 BitCount = 140 ID = 418119424x 0.197693 1 18EBFF00x Rx d 8 03 E1 00 4B FF FF 3C 0F Length = 283910 BitCount = 146 ID = 418119424x 0.248765 1 18EBFF00x Rx d 8 04 00 4B FF FF FF FF FF Length = 283910 BitCount = 146 ID = 418119424x 0.297743 1 J1939TP FEE3p 6 0 0 - Rx d 23 A0 0F A6 60 3B D1 40 1F DE 80 25 DF C0 2B E1 00 4B FF FF 3C 0F 00 4B FF FF FF FF FF FF FF FF FF FF FF FF

[felixdivo]

We should probably document that behavior in the class. Can you do that?

Besides, is there some official documentation of the file format we can link to?

Of course. In a real logfile the J1939TP entry would be preceded by a number of normal CAN messages containing parts of the J1939TP message. Should I also include those in the example file?

Why not add the J1939TP in a few places, like at the start, in between and at the end? It shouldn't hurt.

[bessman]

Besides, is there some official documentation of the file format we can link to?

Not to my knowledge.

[felixdivo]

Thank you @bessman for these improvements!