Re: [ROOT] TPolyLine(3D) Streamer problem? - change in the meaning of SPLIT parameter in 3.01/06

From: Pasha Murat (630)840-8237@169G ((630)840-8237@169G)
Date: Tue Jul 17 2001 - 19:17:08 MEST


Gerco Onderwater wrote:
> 
> Hi Rene,
> 
> As a matter of fact, we just figured out that splitlevel 0 will do the
> job. A value -1, as you suggested, produces the same results as kTRUE
> (which is indeed incorrect).
> 
> On Tue, 17 Jul 2001, Rene Brun wrote:
> 
> > Hi Gerco,
> >
> > TPolyLine3D is one of the few ROOT classes still with a hand-written Streamer.
> > Classes with a hand-written Streamer cannot be used in split mode in a branch.
> > You can force the branch to not use the split mode and call the Streamer
> > function by using split=-1. We expect this to be automatic in the next release.
> > So, in your example, change the line:
> >
>
Dear ROOTers,

I think that the fact that the meaning of 'split' parameter has changed 
in 3.01 needs more advertizing. Much more. Everybody using customized Streamers 
should be warned - this change may affect people in a severe way. A brief comment 
in the release notes is not enough. 
	We'are using hand-written Streamers and I just spent few hours of 
debugging to figure that after switching to ROOT 3.01/06 we were supposed to 
change split=0 to split=-1 in the depths of the code, luckily this was caught 
during the testing.
						-best, Pasha

P.S. In case of no compression customization of Streamers can significantly improve 
     the I/O performance (I saw improvements by a factor of 3), so it seems to be a 
     very reasonable option to consider.



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