Re: automatic Streamer

From: Rene Brun <brun_at_pcroot.cern.ch>
Date: Wed, 8 Jun 2005 14:13:27 +0200 (MEST)


Hi gero,

yes, you understood my point correctly. The new Streamer is more efficient than the old one when it finds consecutive data members of the same type.

Rene Brun

On Wed, 8
Jun 2005, Gero Flucke wrote:

> On Tue, 7 Jun 2005, Rene Brun wrote:
>
>> Hi Gero,
>>
>> If you have consecutive data members of the same type, the automatic
>> Streamer is faster.
>> In addition, the automatic schema evolution is only available with
>> the automatic Streamers.
>> We STRONGLY recommend to use the automatic Streamers.
>
> Hi Rene,
> thanks for explanation, just for being sure that I understand you
> correctly:
> By 'consecutive data members of the same type' you mean that class data
> members are ordered by their type, e.g.
>
> class MyClass : public TObject{
> Float_t fFloat1;
> Float_t fFloat2;
> Int_t fInt;
>
> ClassDef(MyClass)
> }
>
> is (with 'new' Streamer) better than
>
> class MyClass : public TObject{
> Float_t fFloat1;
> Int_t fInt;
> Float_t fFloat2;
>
> ClassDef(MyClass)
> }
>
> Am I right?
>
> Cheers
>
> Gero
>
>> On Tue, 7 Jun 2005, Gero Flucke wrote:
>>
>>> Hi,
>>> is there a general rule which automatically generated streamer mechansim
>>> is faster:
>>> The (very) old one or the "new" introduced in ROOT 3.0 and activated if I
>>> have in my LinkDef.h
>>>
>>> #pragma link C++ class MyClass+;
>>>
>>> with the '+' in the end.
>>>
>>> Cheers
>>>
>>> Gero
>
> --
> -----------------------------------------------------------------------
> Gero Flucke
> 1a / 603
> DESY
> Notkestr. 85
> 22607 Hamburg
> +49-(0)40-8998-2454
>
Received on Wed Jun 08 2005 - 14:13:32 MEST

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