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Reference Guide
mergeSelective.C
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1/// \file
2/// \ingroup tutorial_io
3/// \notebook -nodraw
4/// Merge only part of the content of a set of files.
5/// This macro demonstrates how to merge only a part of the content of a set
6/// of input files, specified via the interface.
7/// ~~~{.cpp}
8/// TFileMerger::AddObjectNames(const char *names)
9/// ~~~
10/// The method can be called several times to add object names, or using a single
11/// string with names separated by a blank. Directory names contained in the files
12/// to be merged are accepted.
13///
14/// Two modes are supported:
15/// 1. kOnlyListed: via <tt>TFileMerger::PartialMerge(kOnlyListed)</tt>
16/// This will merge only the objects in the files having the names in the
17/// specified list. If a folder is specified, its whole content will be merged
18///
19/// 2. kSkipListed: via <tt>TFileMerger::PartialMerge(kSkipListed)</tt>
20/// This will skip merging of specified objects. If a folder is specified, its
21/// whole content will be skipped.
22///
23/// Important note: the kOnlyListed and kSkipListed flags have to be bitwise OR-ed
24/// on top of the merging defaults: kAll | kIncremental (as in the example)
25///
26/// The files to be merged have the following structure:
27/// - hpx (TH1F)
28/// - hpxpy (TH2F)
29/// - hprof (TProfile)
30/// - ntuple (TNtuple)
31/// - folder (TDirectory)
32/// - hpx1 (TH1F)
33///
34/// The example first merges exclusively hprof and the content of "folder",
35/// producing the file exclusive.root, then merges all content but skipping
36/// hprof and the content of "folder". The result can be inspected in the
37/// browser.
38///
39/// \macro_code
40///
41/// \author The Root Team
42
43
44void CreateFile(const char *);
45
46void mergeSelective(Int_t nfiles=5)
47{
48
49 // Create the files to be merged
50 TStopwatch timer;
51 timer.Start();
52 TString tutdir = gROOT->GetTutorialDir();
53 if (gROOT->LoadMacro(tutdir + "/hsimple.C")) return;
54 Int_t i;
55 for (i=0; i<nfiles; i++) CreateFile(Form("tomerge%03d.root",i));
56
57 //------------------------------------
58 // Merge only the listed objects
59 //------------------------------------
60 TFileMerger *fm;
61 fm = new TFileMerger(kFALSE);
62 fm->OutputFile("exclusive.root");
63 fm->AddObjectNames("hprof folder");
64 for (i=0; i<nfiles; i++) fm->AddFile(Form("tomerge%03d.root",i));
65 // Must add new merging flag on top of the default ones
67 Int_t mode = default_mode | TFileMerger::kOnlyListed;
68 fm->PartialMerge(mode);
69 fm->Reset();
70
71 //------------------------------------
72 // Skip merging of the listed objects
73 //------------------------------------
74 fm->OutputFile("skipped.root");
75 fm->AddObjectNames("hprof folder");
76 for (i=0; i<nfiles; i++) fm->AddFile(Form("tomerge%03d.root",i));
77 // Must add new merging flag on top of the default ones
78 mode = default_mode | TFileMerger::kSkipListed;
79 fm->PartialMerge(mode);
80 delete fm;
81
82
83 // Cleanup initial files
84 for (i=0; i<nfiles; i++) gSystem->Unlink(Form("tomerge%03d.root",i));
85 // Open files to inspect in the browser
86 TFile::Open("exclusive.root");
87 TFile::Open("skipped.root");
88 new TBrowser();
89 timer.Stop();
90 timer.Print();
91}
92
93void CreateFile(const char *fname)
94{
95 TFile *example = (TFile*)gROOT->ProcessLineFast("hsimple(1)");
96 if (!example) return;
97 TH1F *hpx = (TH1F*)example->Get("hpx");
98 hpx->SetName("hpx1");
99 TFile::Cp(example->GetName(), fname);
100 TFile *file = TFile::Open(fname, "UPDATE");
101 file->mkdir("folder")->cd();
102 hpx->Write();
103 file->Close();
104 example->Close();
105 TString sname(fname);
106 if (sname.Contains("000")) {
107 TFile::Cp(fname, "original.root");
108 TFile::Open("original.root");
109 }
110}
int Int_t
Definition: RtypesCore.h:45
const Bool_t kFALSE
Definition: RtypesCore.h:101
Option_t Option_t TPoint TPoint const char mode
#define gROOT
Definition: TROOT.h:406
char * Form(const char *fmt,...)
Formats a string in a circular formatting buffer.
Definition: TString.cxx:2468
R__EXTERN TSystem * gSystem
Definition: TSystem.h:560
Using a TBrowser one can browse all ROOT objects.
Definition: TBrowser.h:37
This class provides file copy and merging services.
Definition: TFileMerger.h:30
virtual Bool_t OutputFile(const char *url, Bool_t force)
Open merger output file.
virtual Bool_t AddFile(TFile *source, Bool_t own, Bool_t cpProgress)
Add the TFile to this file merger and give ownership of the TFile to this object (unless kFALSE is re...
void AddObjectNames(const char *name)
Definition: TFileMerger.h:101
@ kAll
Merge all type of objects (default)
Definition: TFileMerger.h:76
@ kIncremental
Merge the input file with the content of the output file (if already existing).
Definition: TFileMerger.h:71
@ kSkipListed
Skip objects specified in fObjectNames list.
Definition: TFileMerger.h:80
@ kOnlyListed
Only the objects specified in fObjectNames list.
Definition: TFileMerger.h:79
virtual Bool_t PartialMerge(Int_t type=kAll|kIncremental)
Merge the files.
virtual void Reset()
Reset merger file list.
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition: TFile.h:54
virtual Bool_t Cp(const char *dst, Bool_t progressbar=kTRUE, UInt_t buffersize=1000000)
Allows to copy this file to the dst URL.
Definition: TFile.cxx:4973
static TFile * Open(const char *name, Option_t *option="", const char *ftitle="", Int_t compress=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault, Int_t netopt=0)
Create / open a file.
Definition: TFile.cxx:4053
1-D histogram with a float per channel (see TH1 documentation)}
Definition: TH1.h:577
void SetName(const char *name) override
Change the name of this histogram.
Definition: TH1.cxx:8826
virtual Int_t Write(const char *name=nullptr, Int_t option=0, Int_t bufsize=0)
Write this object to the current directory.
Definition: TObject.cxx:874
Stopwatch class.
Definition: TStopwatch.h:28
void Start(Bool_t reset=kTRUE)
Start the stopwatch.
Definition: TStopwatch.cxx:58
void Stop()
Stop the stopwatch.
Definition: TStopwatch.cxx:77
void Print(Option_t *option="") const override
Print the real and cpu time passed between the start and stop events.
Definition: TStopwatch.cxx:219
Basic string class.
Definition: TString.h:136
virtual int Unlink(const char *name)
Unlink, i.e.
Definition: TSystem.cxx:1384
Definition: file.py:1