Is anyone else bothered by the slight irregularity of babeltrace's output?
Here is the same trace record printed using various babeltrace settings. In
all cases I used '-f trace:hostname --no-delta', varying only the '-n' part:
-n scope
[11:02:08.064705355] edge-vb-u12 exit_syscall: stream.packet.context = { 0 },
stream.event.context = { 1, 943, "whoopsie", 943, 109 }, event.fields = 8
-n payload
[11:02:08.064705355] edge-vb-u12 exit_syscall: { 0 }, { 1, 943, "whoopsie",
943, 109 }, { ret = 8 }
-n none
[11:02:08.064705355] edge-vb-u12 exit_syscall: { 0 }, { 1, 943, "whoopsie",
943, 109 }, 8
-n all
timestamp = 11:02:08.064705355, trace:hostname = edge-vb-u12, name =
exit_syscall, stream.packet.context = { cpu_id = 0 }, stream.event.context = {
ppid = 1, tid = 943, procname = "whoopsie", pid = 943, perf_major_faults = 109
}, event.fields = { ret = 8 }
Now compare just the payload part:
-n scope
event.fields = 8
-n payload
{ ret = 8 }
-n none
8
-n all
event.fields = { ret = 8 }
It turns out the payload is bracketed by {} except when it has size zero or one
and its contents are unlabelled. Indeed, with an empty payload I can get a
trailing "{ }" or "" (that is to say, the record ends with a comma) depending
on the labelling. However, notice that for the stream.packet.context this does
not happen, maybe because the underlying structure has actually six fields
instead of the lone one normally shown (you can get all six printed using
--verbose):
-n scope
stream.packet.context = { 0 },
-n payload
{ 0 },
-n none
{ 0 },
-n all
stream.packet.context = { cpu_id = 0 },
-v
{ timestamp_begin = 4196192044293, timestamp_end = 4196224429641, content_size
= 2096768, packet_size = 2097152, events_discarded = 0, cpu_id = 0 },
This variability could make babeltrace's text output more difficult to parse
than necessary, since one would have to handle the occasionally-disappearing
curly brackets.
Is this worth filing a bug over?
Daniel U. Thibault
R & D pour la défense Canada - Valcartier (RDDC Valcartier) / Defence R&D
Canada - Valcartier (DRDC Valcartier)
Cyber sécurité pour les missions essentielles (CME) / Mission Critical Cyber
Security (MCCS)
Protection des systèmes et contremesures (PSC) / Systems Protection &
Countermeasures (SPC)
2459 route de la Bravoure
Québec, QC G3J 1X5
CANADA
Vox : (418) 844-4000 x4245
Fax : (418) 844-4538
NAC : 918V QSDJ <http://www.travelgis.com/map.asp?addr=918V%20QSDJ>
Gouvernement du Canada / Government of Canada
<http://www.valcartier.drdc-rddc.gc.ca/>
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