void mergeSelective(Int_t nfiles=5)
{
// This macro demonstrates how to merge only a part of the content of a set
// of input files, specified via the interface:
// TFileMerger::AddObjectNames(const char *names)
// The method can be called several times to add object names, or using a single
// strings with names separated by a blank. Directory names contained in the files
// to be merged are accepted.
//
// Two modes are supported:
// == kOnlyListed: via TFileMerger::PartialMerge(kOnlyListed)
// This will merge only the objects in the files having the names in the
// specified list. If a folder is specified, it whole content will be merged
//
// == kSkipListed: via TFileMerger::PartialMerge(kSkipListed)
// This will skip merging of specified objects. If a folder is specified, its
// whole content will be skipped.
//
// Important note: the kOnlyListed and kSkipListed flags have to be bitwise OR-ed
// on top of the merging defaults: kAll | kIncremental (as in the example)
//
// The files to be merged have the following structure:
// - hpx (TH1F)
// - hpxpy (TH2F)
// - hprof (TProfile)
// - ntuple (TNtuple)
// = folder (TDirectory)
// - hpx1 (TH1F)
//
// The example first merges exclusively hprof and the content of "folder",
// producing the file exclusive.root, then merges all content but skipping
// hprof and the content of "folder". The result can be inspected in the
// browser.
// Create the files to be merged
TStopwatch timer;
timer.Start();
if (gROOT->LoadMacro("$ROOTSYS/tutorials/hsimple.C")) return;
Int_t i;
for (i=0; i<nfiles; i++) CreateFile(Form("tomerge%03d.root",i));
//------------------------------------
// Merge only the listed objects
//------------------------------------
TFileMerger *fm;
fm = new TFileMerger(kFALSE);
fm->OutputFile("exclusive.root");
fm->AddObjectNames("hprof folder");
for (i=0; i<nfiles; i++) fm->AddFile(Form("tomerge%03d.root",i));
// Must add new merging flag on top of the the default ones
Int_t default_mode = TFileMerger::kAll | TFileMerger::kIncremental;
Int_t mode = default_mode | TFileMerger::kOnlyListed;
fm->PartialMerge(mode);
fm->Reset();
//------------------------------------
// Skip merging of the listed objects
//------------------------------------
fm->OutputFile("skipped.root");
fm->AddObjectNames("hprof folder");
for (i=0; i<nfiles; i++) fm->AddFile(Form("tomerge%03d.root",i));
// Must add new merging flag on top of the the default ones
mode = default_mode | TFileMerger::kSkipListed;
fm->PartialMerge(mode);
delete fm;
// Cleanup initial files
for (i=0; i<nfiles; i++) gSystem->Unlink(Form("tomerge%03d.root",i));
// Open files to inspect in the browser
TFile::Open("exclusive.root");
TFile::Open("skipped.root");
new TBrowser();
timer.Stop();
timer.Print();
}
