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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:

http://localhost:8080
#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 "THttpServer.h"
void httpserver(const char* jobname = "job1", Long64_t maxcnt = 0)
{
auto filename = TString::Format("%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);
hpx->SetFillColor(48);
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");
hfile->Write();
// http server with port 8080, use jobname as top-folder name
THttpServer* serv = new THttpServer(TString::Format("http:8080?top=%s", jobname));
// fastcgi server with port 9000, use jobname as top-folder name
// THttpServer* serv = new THttpServer(TString::Format("fastcgi:9000?top=%s_fastcgi", 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/js/latest/");
// serv->SetJSROOT("https://jsroot.gsi.de/latest/");
gBenchmark->Start(jobname);
// Create a new canvas.
TCanvas *c1 = new TCanvas("c1","Dynamic Filling Example",200,10,700,500);
c1->SetFillColor(42);
c1->GetFrame()->SetFillColor(21);
c1->GetFrame()->SetBorderSize(6);
c1->GetFrame()->SetBorderMode(-1);
// Fill histograms randomly
TRandom3 random;
Float_t px, py, pz;
const Int_t kUPDATE = 1000;
Long64_t i = 0;
while (true) {
random.Rannor(px,py);
pz = px*px + py*py;
Float_t rnd = random.Rndm(1);
hpx->Fill(px);
hpxpy->Fill(px,py);
hprof->Fill(px,pz);
// 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();
c1->Modified();
c1->Update();
if (i == kUPDATE) hfile->Write();
if (gSystem->ProcessEvents()) break;
}
i++;
if ((maxcnt>0) && (i>=maxcnt)) break;
}
gBenchmark->Show(jobname);
}
int Int_t
Signed integer 4 bytes (int).
Definition RtypesCore.h:59
constexpr Bool_t kFALSE
Definition RtypesCore.h:108
long long Long64_t
Portable signed long integer 8 bytes.
Definition RtypesCore.h:83
float Float_t
Float 4 bytes (float).
Definition RtypesCore.h:71
externTBenchmark * gBenchmark
Definition TBenchmark.h:59
externTSystem * gSystem
Definition TSystem.h:582
The Canvas class.
Definition TCanvas.h:23
A file, usually with extension .root, that stores data and code in the form of serialized objects in ...
Definition TFile.h:130
Int_t Write(const char *name=nullptr, Int_t opt=0, Int_t bufsize=0) override
Write memory objects to this file.
Definition TFile.cxx:2488
1-D histogram with a float per channel (see TH1 documentation)
Definition TH1.h:878
2-D histogram with a float per channel (see TH1 documentation)
Definition TH2.h:345
Int_t Fill(Double_t) override
Invalid Fill method.
Definition TH2.cxx:363
Online http server for arbitrary ROOT application.
Definition THttpServer.h:31
void SetReadOnly(Bool_t readonly=kTRUE)
Set read-only mode for the server (default on).
A TMemFile is like a normal TFile except that it reads and writes only from memory.
Definition TMemFile.h:27
A simple TTree restricted to a list of float variables only.
Definition TNtuple.h:28
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
Double_t Rndm() override
Machine independent random number generator.
Definition TRandom3.cxx:107
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:506
static TString Format(const char *fmt,...)
Static method which formats a string using a printf style format descriptor and return a TString.
Definition TString.cxx:2385
return c1
Definition legend1.C:41
Author
Sergey Linev

Definition in file httpserver.C.