Re: [linuxtools-dev] TMF: Analysis requirement API

[Alexandre Montplaisir <alexmonthy@xxxxxxxxxxxx>]

Hi Guilliano,

Interesting project! Indeed, there is already an API for traces to
indicate if they contain specific events (hasEvent(String),
hasAllEvents(String[]),...).[1]  The next step would be to have a way
for an analysis to specify which event types they need, so we can match
the traces and analyses better.

Some questions:
- A "string" requirement is quite generic. What actual types of
requirements do you have in mind? I can see event type (or event name),
but what else? If we can pinpoint a few specific types of requirements,
we could have a couple of methods specifically for those. Having
something too vague or too generic makes it more confusing to use, and
we don't have as much compile-time guarantees.

- Were you thinking about simply adding new API methods to
IAnalysisModule, or going through the analysis-module extension point?
Extension points are very powerful, but the golden rule is: don't use
them if you don't need to :)  In this particular case, I think you could
make do without it, but we would have to see.


Cheers,
Alex


[1] It's only in CtfTmfTrace for now, because it's quite quick for CTF
traces to just look in the metadata for existing even types. Perhaps
this could be a good time to move it up to ITmfTrace, so it can be
implemented for other trace types.



On 14-02-19 11:40 AM, Guilliano Molaire wrote:
> Hi everyone,
>
> Mathieu Rail and I, Guilliano Molaire, are working on the TMF part of
> linuxtools. Our main goal
> is to provide an API for the analysis modules that will permit queries
> of their requirements.
>
> A requirement is basically a string container of his type (e.g.
> "event_name") and all the values associated with it (e.g.
> "sched_switch").
> Other properties will be added. For instance, a requirement(or value
> perhaps) could be mandatory or facultative.
>
> This API will be used later to provide a way to obtain everything
> needed to start a trace on which the analysis can be executed.
> In the LTTng case, we could generate a profile with the requirements
> in order to load it via the target machine.
>
> You can follow our progress on github (branch analysis_requirement):
> https://github.com/MathieuRail/org.eclipse.linuxtools
>
> We are open to your feedback.
>
> Thanks,
> Guilliano and Mathieu
>