i have encountered a problem in ROOT 1.03/08.
I have a class containing a static sized array of Int_t's. Writing the class
in a file and rereading it, results in a only partially filled array.
The first element will be filled only.
Below you can find an example code. Running this gives the correct result :
aruba:bos2root 28> \nice ./a.out
0 -> 0
1 -> 1
2 -> 2
3 -> 3
4 -> 4
0 -> 0
1 -> 1
2 -> 2
3 -> 3
4 -> 4
0 -> 0
1 -> 1
2 -> 2
3 -> 3
4 -> 4
TFile Writing Name=Event.root Title=TTree benchmark ROOT file
Rereading the file gives :
root [0] gSystem.Load("libfoo.so");
root [1] TFile *hfile = new TFile("Event.root");
root [2] TTree *tree = (TTree *)hfile->Get("T");
root [3] TBranch *b = tree->GetBranch("Foo");
root [4] gEvent = new Foo();
root [5] b->SetAddress(&gEvent);
root [6] tree->GetEvent(0)
(Int_t)12
root [7] gEvent->Print()
0 -> 0
1 -> -1
2 -> -1
3 -> -1
4 -> -1
root [8] gEv = new Foo();
root [9] gEv->Print()
0 -> -1
1 -> -1
2 -> -1
3 -> -1
4 -> -1
root [10]
so ... only the array element 0 is read from file.
Ciao
Thomas
----------------------------------------------------------------------------
Thomas Hadig, Ottensen, Donnerstr. 20, D-22763 Hamburg (++49 40 39901186)
office : I. Phys. Institut AAC, Room 1c354, Notkestr. 85, D-22603 Hamburg
hadig@rwth-aachen.de Tel. ++49 40 8998 2312
http://www-h1.desy.de/~hadig/ FAX ++49 40 8998 4385
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In a world without walls and fences, who needs windows and gates ?
----------------------------------------------------------------------------
--------------------------------------------------foo.h--------------------
#include <iostream.h>
#include <TObject.h>
class Foo : public TObject
{
public:
Int_t entry[5];
Foo();
void Set();
void Print();
ClassDef (Foo,1)
};
--------------------------------------------------foo.C--------------------
#include "foo.h"
Foo::Foo()
{
for (Int_t i=0; i<5; i++) entry[i]=-1;
}
void Foo::Print()
{
for (Int_t i=0; i<5; i++) cout << i << " -> " << entry[i] << endl;
}
void Foo::Set()
{
for (Int_t i=0; i<5; i++) entry[i]=i;
}
ClassImp(Foo)
--------------------------------------------------foo2.C--------------------
#include <stdlib.h>
#include <iostream.h>
#include <TROOT.h>
#include <TFile.h>
#include <TTree.h>
#include <TBranch.h>
#include "foo.h"
Foo* gEvent;
int main (int argc, char **argv)
{
TROOT simple("simple","Example of creation of a tree");
Int_t eventno=0;
gEvent = new Foo();
TFile *hfile = new TFile("/tmp/Event.root","RECREATE","TTree benchmark ROOT file");
hfile->SetCompressionLevel(1);
TTree *tree = new TTree("T","An example of a ROOT tree");
tree->SetAutoSave(1000000000); // autosave when 1 Gbyte written
Int_t bufsize = 64000;
Int_t split = 1;
TBranch *b = tree->Branch("Foo", "Foo", &gEvent, bufsize,split);
Int_t nb=0;
while (eventno<3)
{
eventno++;
gEvent->Set();
nb+=tree->Fill();
gEvent->Print();
}
hfile->Write();
hfile->Close();
return 0;
}
--------------------------------------------------domake--------------------
make foo.o
rootcint -f foocint.C -c foo.h LinkDef.h
make foocint.o
g++ -Wl,-soname,libfoo.so -shared -g -Wl,-u,__builtin_new -Wl,-u,__builtin_delete -Wl,-u,__nw__FUiPv foo.o foocint.o -o libfoo.so
make foo2.o
g++ -Wl,-u,__builtin_new -Wl,-u,__builtin_delete -Wl,-u,__nw__FUiPv -o a.out foo2.o -L. -lfoo -L/cern/root_gcc/lib -lBase -lCint -lClib -lCont -lFunc -lGraf -lGraf3d -lHist -lHtml -lMeta -lMinuit -lNet -lPostscript -lProof -lTree -lUnix -lZip -lg++ -lm -ldl -L/afs/desy.de/group/h1/lib -lh1util -lfpack -lbos -L/cern/pro/lib -lgrafX11 -lmathlib -lgenlib -lkernlib -lpacklib -lgenlib -L/usr/lib -lftn -lh1ndb
\nice ./a.out
--------------------------------------------------END--------------------