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httpserver.C File Reference

Detailed Description

This program creates :

  • a one dimensional histogram
  • a two dimensional histogram
  • a profile histogram
  • a memory-resident ntuple

These objects are filled with some random numbers and saved on a in-memory file. All objects can be seen in web browser is open url:

#include <TFile.h>
#include <TMemFile.h>
#include <TNtuple.h>
#include <TH2.h>
#include <TProfile.h>
#include <TCanvas.h>
#include <TFrame.h>
#include <TROOT.h>
#include <TSystem.h>
#include <TRandom3.h>
#include <TBenchmark.h>
#include <TInterpreter.h>
#include <THttpServer.h>
void httpserver(const char* jobname = "job1", Long64_t maxcnt = 0)
TString filename = Form("%s.root", jobname);
TFile *hfile = new TMemFile(filename,"RECREATE","Demo ROOT file with histograms");
// Create some histograms, a profile histogram and an ntuple
TH1F *hpx = new TH1F("hpx","This is the px distribution",100,-4,4);
TH2F *hpxpy = new TH2F("hpxpy","py vs px",40,-4,4,40,-4,4);
TProfile *hprof = new TProfile("hprof","Profile of pz versus px",100,-4,4,0,20);
TNtuple *ntuple = new TNtuple("ntuple","Demo ntuple","px:py:pz:random:i");
// http server with port 8080, use jobname as top-folder name
THttpServer* serv = new THttpServer(Form("http:8080?top=%s", jobname));
// fastcgi server with port 9000, use jobname as top-folder name
// THttpServer* serv = new THttpServer(Form("fastcgi:9000?top=%s_fastcgi", jobname));
// dabc agent, connects to DABC master_host:1237, works only when DABC configured
// THttpServer* serv = new THttpServer(Form("dabc:master_host:1237?top=%s_dabc", jobname));
// when read-only mode disabled one could execute object methods like TTree::Draw()
// One could specify location of newer version of JSROOT
// serv->SetJSROOT("https://root.cern.ch/js/latest/");
// serv->SetJSROOT("http://jsroot.gsi.de/latest/");
// Create a new canvas.
TCanvas *c1 = new TCanvas("c1","Dynamic Filling Example",200,10,700,500);
// Fill histograms randomly
TRandom3 random;
Float_t px, py, pz;
const Int_t kUPDATE = 1000;
Long64_t i = 0;
while (true) {
pz = px*px + py*py;
Float_t rnd = random.Rndm(1);
// fill only first 25000 events in NTuple
if (i<25000) ntuple->Fill(px,py,pz,rnd,i);
if (i && (i%kUPDATE) == 0) {
if (i == kUPDATE) hpx->Draw();
if (i == kUPDATE) hfile->Write();
if (gSystem->ProcessEvents()) break;
if ((maxcnt>0) && (i>=maxcnt)) break;
int Int_t
Definition RtypesCore.h:45
const Bool_t kFALSE
Definition RtypesCore.h:101
long long Long64_t
Definition RtypesCore.h:80
float Float_t
Definition RtypesCore.h:57
R__EXTERN TBenchmark * gBenchmark
Definition TBenchmark.h:59
char * Form(const char *fmt,...)
R__EXTERN TSystem * gSystem
Definition TSystem.h:559
virtual void SetFillColor(Color_t fcolor)
Set the fill area color.
Definition TAttFill.h:37
virtual void Start(const char *name)
Starts Benchmark with the specified name.
virtual void Show(const char *name)
Stops Benchmark name and Prints results.
The Canvas class.
Definition TCanvas.h:23
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition TFile.h:54
Int_t Write(const char *name=nullptr, Int_t opt=0, Int_t bufsiz=0) override
Write memory objects to this file.
Definition TFile.cxx:2374
1-D histogram with a float per channel (see TH1 documentation)}
Definition TH1.h:575
virtual Int_t Fill(Double_t x)
Increment bin with abscissa X by 1.
Definition TH1.cxx:3351
virtual void Draw(Option_t *option="")
Draw this histogram with options.
Definition TH1.cxx:3074
2-D histogram with a float per channel (see TH1 documentation)}
Definition TH2.h:251
Int_t Fill(Double_t)
Invalid Fill method.
Definition TH2.cxx:358
void SetReadOnly(Bool_t readonly=kTRUE)
Set read-only mode for the server (default on) In read-only server is not allowed to change any ROOT ...
A TMemFile is like a normal TFile except that it reads and writes only from memory.
Definition TMemFile.h:19
A simple TTree restricted to a list of float variables only.
Definition TNtuple.h:28
virtual Int_t Fill()
Fill a Ntuple with current values in fArgs.
Definition TNtuple.cxx:169
Profile Histogram.
Definition TProfile.h:32
Int_t Fill(const Double_t *v)
Definition TProfile.h:55
Random number generator class based on M.
Definition TRandom3.h:27
virtual Double_t Rndm()
Machine independent random number generator.
Definition TRandom3.cxx:99
virtual void Rannor(Float_t &a, Float_t &b)
Return 2 numbers distributed following a gaussian with mean=0 and sigma=1.
Definition TRandom.cxx:500
Basic string class.
Definition TString.h:136
virtual Bool_t ProcessEvents()
Process pending events (GUI, timers, sockets).
Definition TSystem.cxx:419
return c1
Definition legend1.C:41
Sergey Linev

Definition in file httpserver.C.