I finally solved the problem of moving directories. Here is the code
fragment which does the trick:
...
// Get list of root objects in memory, then create the new file.
// Iterate on list and transfer objects from old to new file.
TList* list1= gDirectory->GetList();
TIter iter( list1 );
TFile* filep= new TFile( file, "RECREATE",
"Created for you again by RooTupleManager" );
TList* list2= filep->GetList();
TObject* obj= 0;
while( obj= iter.Next() ) {
if( obj->InheritsFrom( "TH1" ) ) {
// TH1::SetDirectory does all the work for us:
((TH1*)obj)->SetDirectory( gDirectory );
}
else if( strcmp( obj->ClassName(), "TDirectory" ) == 0 ) {
// Have to do it by hand for TDirectory:
list1->Remove( obj );
list2->Add( obj );
((TDirectory*)obj)->SetMother( gDirectory );
}
}
...
I hadn't realised that TH1::SetDirectory already does the transfer and
ended up doing it twice, with weird consequences.
Actually, a similar member function for TDirectory
(TDirectory::SetDirectory( TDirectory* target )) would be nice. This would
help implementing a TDirectory::Mv( TObject* obj, TDirectory* target ) I
guess.
Could this be done for TTrees too? I think it could, if one takes care to
flush buffers before moving a TTree from one file to another. So, One
would also need a new member function
TTree::SetDirectory( TDirectory* target ).
cheers, Stefan
---Stefan Kluth---------------Lynen Fellow----------------|\--|\-------
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