[linuxtools-dev] [lttng] CTFTraceReader inconsistencies

[Francis Giraldeau <francis.giraldeau@xxxxxxxxx>]

Hi,

There seems to exists inconsistency in CTFTraceReader timestamps.

* getStartTime() returns a raw timestamps

* A call to getEndTime() after object instantiation returns a raw
timestamps equals to start.

* After reading an event, getEndTime() returns the timestamps + offset
of the trace.

When start has no offset, this leads to a funny result: duration = end -
start = ~42 years (2012 - 1970)

Also, a seek should be performed with a timestamps relative to start,
not (start + offset). Thus, reader.seek(reader.getEndTime()) if done
after object instantiation returns the first event in the trace, and if
done after goToLastEvent(), returns a null event, because of the offset.

I would suggests that timestamps getters should all adds offset or not,
and that seek should follow the same convention by accepting timestamps
returned by getStartTime() and getEndTime().

On a side note: goToLastEvent() is very not efficient, because all
events in the trace is processed to reach the end. Could it be possible
to directly jump to the end instead?

Cheers,

Francis

Attachment: smime.p7s
Description: Signature cryptographique S/MIME