void treeClient(Bool_t evol=kFALSE)
{
// Client program which creates and fills 2 histograms and a TTree.
// Every 1000000 fills the histograms and TTree is send to the server which displays the histogram.
//
// To run this demo do the following:
// - Open at least 2 windows
// - Start ROOT in the first windows
// - Execute in the first window: .x fastMergeServer.C
// - Execute in the other windows: root.exe -b -l -q .x treeClient.C
// (You can put it in the background if wanted).
// If you want to run the hserv.C on a different host, just change
// "localhost" in the TSocket ctor below to the desired hostname.
//
//Author: Fons Rademakers, Philippe Canal
gBenchmark->Start("treeClient");
// Open connection to server
TSocket *sock = new TSocket("localhost", 9090);
if (!sock->IsValid()) {
Error("treeClient","Could not establish a connection with the server %s:%d.","localhost",9090);
return;
}
// Wait till we get the start message
// server tells us who we are
Int_t status, version, kind;
sock->Recv(status, kind);
if (kind != 0 /* kStartConnection */)
{
Error("treeClient","Unexpected server message: kind=%d status=%d\n",kind,status);
delete sock;
return;
}
sock->Recv(version, kind);
if (kind != 1 /* kStartConnection */)
{
Fatal("treeClient","Unexpected server message: kind=%d status=%d\n",kind,status);
} else {
Info("treeClient","Connected to fastMergeServer version %d\n",version);
}
int idx = status;
Float_t messlen = 0;
Float_t cmesslen = 0;
TMemFile *file = new TMemFile("mergedClient.root","RECREATE");
TH1 *hpx;
if (idx == 0) {
// Create the histogram
hpx = new TH1F("hpx","This is the px distribution",100,-4,4);
hpx->SetFillColor(48); // set nice fillcolor
} else {
hpx = new TH2F("hpxpy","py vs px",40,-4,4,40,-4,4);
}
Float_t px, py;
TTree *tree = new TTree("tree","tree");
tree->SetAutoFlush(4000000);
tree->Branch("px",&px);
tree->Branch("py",&py);
TMessage::EnableSchemaEvolutionForAll(evol);
TMessage mess(kMESS_OBJECT);
// Fill histogram randomly
gRandom->SetSeed();
const int kUPDATE = 1000000;
for (int i = 0; i < 25000000; ) {
gRandom->Rannor(px,py);
if (idx%2 == 0)
hpx->Fill(px);
else
hpx->Fill(px,py);
tree->Fill();
++i;
if (i && (i%kUPDATE) == 0) {
file->Write();
mess.Reset(kMESS_ANY); // re-use TMessage object
mess.WriteInt(idx);
mess.WriteTString(file->GetName());
mess.WriteLong64(file->GetEND()); // 'mess << file->GetEND();' is broken in CINT for Long64_t
file->CopyTo(mess);
sock->Send(mess); // send message
messlen += mess.Length();
cmesslen += mess.CompLength();
file->ResetAfterMerge(0); // This resets only the TTree objects.
hpx->Reset();
}
}
sock->Send("Finished"); // tell server we are finished
if (cmesslen > 0)
printf("Average compression ratio: %g\n", messlen/cmesslen);
gBenchmark->Show("hclient");
// Close the socket
sock->Close();
}
