From mboxrd@z Thu Jan  1 00:00:00 1970
From: jerome.stadelmann@heig-vd.ch (=?iso-8859-1?q?J=E9r=F4me_Stadelmann?=)
Date: Tue, 24 Mar 2009 09:34:37 +0100
Subject: [ltt-dev] Traces data alignment
In-Reply-To: <20090320145355.GA29127@Krystal>
References: <200903191606.35831.jerome.stadelmann@heig-vd.ch>
	<200903200816.39240.jerome.stadelmann@heig-vd.ch>
	<20090320145355.GA29127@Krystal>
Message-ID: <200903240934.37456.jerome.stadelmann@heig-vd.ch>

On vendredi 20 mars 2009 15:53:55 Mathieu Desnoyers wrote:
> * J?r?me Stadelmann (jerome.stadelmann at heig-vd.ch) wrote:
> > On jeudi 19 mars 2009 18:00:01 Mathieu Desnoyers wrote:
> > > * J?r?me Stadelmann (jerome.stadelmann at heig-vd.ch) wrote:
> > > > Hi everybody,
> > > > 
> > > > I'm working on a LTTng traces parser and I'm a little bit blocked on the alignment. Can someone please explain how and where it is coded ?
> > > 
> > > The lttv lib "ltttraceread" should do that for you.
> >  
> > > > What are the roles of the alignment defined in the traces header and the one defined in the metadata file in the core_marker_id ?
> > > > 
> > > 
> > > They tell that a specific tracefile content is aligned or not, and if
> > > the content of a given event is aligned or not. You should really have
> > > at least a look at the ltt lib traceread reference implementation.
> > 
> > Thank you. This library helped me a lot. I see that there is an up to 2 byte alignment in the core marker id event definition. Is there the only special case ?
> > I've searched the uses of the ltt_align function. Are there other functions to look for ?
> > 
> 
> Looking at ltt_align use is a good starting point.
> 
> Can you point out to the specific package/version/file/line you refer to
> for the core marker id "special case" you talk about here ?
> 

I think I've understood now. The alignment in the metadata file is "hardcoded" as 2 byte because the id field is the biggest value and is coded as a 2 bytes value. Am I right ?

> Mathieu
> 
> > Jerome
> >  
> > > Mathieu
> > > 
> > > > Regards,
> > > > Jerome
> > > > 
> > > > _______________________________________________
> > > > ltt-dev mailing list
> > > > ltt-dev at lists.casi.polymtl.ca
> > > > http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
> > > > 
> > > 
> > 
>