Hi,
Could you add a statement:
fTree->Print();
just after fTree->Write(..
then in the program reading the file, do:
TFile *file = new TFile( argv[1] );
f->ShowTreamerInfo(); //<===add this line
and
TBranch *logb = tree->GetBranch( "LogBranch" );
logb->SetAddress( &logm ); // I assume you have LogMessage *logm = 0;
gDebug=2; //(need #include "Tsystem.h") <===add this line
Send me the output
Rene Brun
Hermann-Josef.Mathes@ik.fzk.de wrote:
>
> Dear rooters,
>
> I have a problem in reading objects written to a tree from my program. If
> I load the shared library into a ROOT session, everything works fine, I
> can see the leaves of the branch and plot their content.
>
> Writing is done in the following way:
>
> LogMessage *fLogMessage = new LogMessage();
>
> TFile* fLogFile = new TFile( filename, "recreate" );
>
> TTree* fTree = new TTree( "LogTree", "Tree containing LogMessage objects" );
>
> // class LogMessage in namespace Logging
> fTree->Branch( "LogBranch", "Logging::LogMessage", &fLogMessage, 10000, 1 );
>
> fTree->Fill();
>
> after writing many LogMessage objects to the file I do:
>
> fLogFile->Write( 0, TObject::kOverwrite );
> fLogFile->Close();
>
> Reading is (should be) then done be the following code fragment:
> (I tried also the variants as offered by the MakeClass() method).
>
> TFile *file = new TFile( argv[1] );
> TTree *tree = (TTree *)file->Get( "LogTree" );
>
> if ( tree ) {
>
> TBranch *logb = tree->GetBranch( "LogBranch" );
> logb->SetAddress( &logm );
> for ( Int_t n_entry=0; n_entry<tree->GetEntries(); n_entry++ ) {
>
> tree->GetEvent( n_entry );
> }
> delete tree;
> }
>
> The code crashes in the GetEvent() method:
> Program received signal SIGSEGV, Segmentation fault.
> 0x4022d930 in G__TString_ShowMembers_3_12__FP8G__valuePCcP8G__parami ()
> at include/TStreamerInfo.h:127
> 127 include/TStreamerInfo.h: No such file or directory.
> (gdb) back
> #0 0x4022d930 in G__TString_ShowMembers_3_12__FP8G__valuePCcP8G__parami ()
> at include/TStreamerInfo.h:127
> #1 0x40560b0e in G__CallFunc::Exec () from /cern/root/lib/libCint.so
> #2 0x4014f063 in TClass::BuildRealData (this=0x84235c8, pointer=0x8467520)
> at meta/src/TClass.cxx:478
> #3 0x40152d92 in TClass::ReadBuffer (this=0x84235c8, b=@0x85401c8,
> pointer=0x8467520) at meta/src/TClass.cxx:1583
> #4 0x40167e31 in TStreamerInfo::ReadBuffer (this=0x841b828, b=@0x85401c8,
> pointer=0x8467510 "", first=2) at meta/src/TStreamerInfo.cxx:1864
> #5 0x40ade7bd in TBranchElement::ReadLeaves () from /cern/root/lib/libTree.so
> #6 0x40ad7e3a in TBranch::GetEntry () from /cern/root/lib/libTree.so
> #7 0x40add6ec in TBranchElement::GetEntry () from /cern/root/lib/libTree.so
> #8 0x40add69c in TBranchElement::GetEntry () from /cern/root/lib/libTree.so
> #9 0x40af3ea0 in TTree::GetEntry () from /cern/root/lib/libTree.so
> #10 0x40af6ae5 in TTree::GetEvent () from /cern/root/lib/libTree.so
> #11 0x804d683 in main (argc=2, argv=0xbfffee24) at FileBrowser.cc:70
>
> I think it is a very trivial error which I do but I cannot find it. Do
> have any suggestions ? I am using 2.03/07
>
> Thank you
> Hermann-Josef
>
> **************************************************************************
> * *
> * Dr. Hermann-Josef Mathes *
> * KASCADE & AUGER Collaboration *
> * Forschungszentrum Karlsruhe Phone: +49 7247 822429 *
> * Institut fuer Kernphysik FAX: +49 7247 824075 *
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> * D-76021 Karlsruhe/Germany Mail: mathes@ik.fzk.de *
> * hjmathes@web.de *
> * *
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