mjsroot.cxx

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//
// MIDAS jsroot server
//
// K.Olchanski
//
 
#undef NDEBUG // this program requires working assert()
 
#include <stdio.h>
#include <assert.h>
#include <signal.h> // signal();
 
#include "TSystem.h"
#include "TFile.h"
#include "TKey.h"
#include "THttpServer.h"
 
//////////////////////////////////////////////////////////
//
//                   main program
//
//////////////////////////////////////////////////////////
 
static void help()
{
  printf("\nUsage: ./mjsroot.exe [-h] -R8081 [file1.root file2.root ...]\n");
  printf("\n");
  printf("-h: print this help message\n");
  printf("\n");
  printf("-Rnnnn: Start the ROOT THttpServer HTTP server on specified tcp port, use -R8081, access by firefox http://localhost:8081\n");
  printf("\n");
  printf("Example: use jsroot to look at a ROOT file: ./mjsroot.exe -R8082 root_output_files/output00371.root; firefox http://localhost:8082\n");
  exit(1);
}
 
// duplicate c++20 std::string s.starts_with()
 
static bool starts_with(const std::string& s, const char* prefix)
{
   return (s.substr(0, strlen(prefix)) == prefix);
}
 
// read all keys from ROOT file. why do we need this?!?
 
void ReadFile(TDirectoryFile *f)
{
   for (TObject* keyobj: *f->GetListOfKeys()) {
      TKey* key = (TKey*)keyobj;
      //printf("key %p, name [%s] title [%s]\n", key, key->GetName(), key->GetTitle());
      TObject* obj = f->Get(key->GetName());
      TClass* t = obj->IsA();
      //printf("obj %p, class [%s], key %p, name [%s], title [%s]\n", obj, t->GetName(), key, key->GetName(), key->GetTitle());
      if (strcmp(t->GetName(), "TDirectoryFile") == 0) {
         ReadFile((TDirectoryFile*)obj);
      }
   }
}
 
// Main function call
 
int main(int argc, char* argv[])
{
   setbuf(stdout, NULL);
   setbuf(stderr, NULL);
 
   signal(SIGILL,  SIG_DFL);
   signal(SIGBUS,  SIG_DFL);
   signal(SIGSEGV, SIG_DFL);
   signal(SIGPIPE, SIG_DFL);
   
   std::vector<std::string> args;
   for (int i=0; i<argc; i++) {
      if (strcmp(argv[i],"-h")==0)
         help(); // does not return
      args.push_back(argv[i]);
   }
 
   int httpPort = 0;
 
   std::vector<std::string> files;
 
   for (unsigned int i=1; i<args.size(); i++) { // loop over the commandline options
      std::string arg = args[i];
      //printf("argv[%d] is %s\n",i,arg);
 
      if (0) {
      } else if (starts_with(arg, "-R")) { // Set the ROOT THttpServer HTTP port
         httpPort = atoi(arg.c_str()+2);
      } else if (arg == "-h") {
         help(); // does not return
      } else if (arg[0] == '-') {
         help(); // does not return
      } else {
         files.push_back(args[i]);
      }
   }
 
   if (httpPort == 0) {
      help(); // does not return
   }
 
   char str[256];
   snprintf(str, sizeof(str), "http:127.0.0.1:%d?cors", httpPort);
 
   THttpServer* httpServer = new THttpServer(str);
 
   if (!httpServer->IsAnyEngine()) {
      fprintf(stderr,"ERROR: Cannot start web server on http port %d, see previous error message.\n", httpPort);
      exit(1);
   }
 
   //s->SetTimer(100, kFALSE);
 
   std::vector<TFile*> root_files;
   
   for (unsigned i=0; i<files.size(); i++) {
      printf("file[%d]: %s\n", i, files[i].c_str());
 
      TFile* f = new TFile(files[i].c_str(), "READ");
   
      if (!f->IsOpen()) {
         fprintf(stderr, "Error: cannot open ROOT file \"%s\"\n", files[i].c_str());
         exit(1);
      }
 
      //f->ReadAll(); // does not read all histograms into memory
      //f->ReadKeys(); // reads all the subdirectories, but not histograms, so everything is in the wrong order
 
      ReadFile(f);
 
      root_files.push_back(f);
   }
 
 
   while (1) {
      int nreq = httpServer->ProcessRequests();
      if (nreq > 0) {
         //printf("ProcessRequests() returned %d\n", nreq);
         continue;
      }
 
      //gSystem->DispatchOneEvent(kTRUE);
 
      bool intr = gSystem->ProcessEvents();
      if (intr)
         break;
 
      usleep(1000);
   }
 
   printf("Interrupted, shutting down!\n");
 
   // shutdown the web server
 
   delete httpServer;
   httpServer = NULL;
 
   // close ROOT files
 
   for (TFile* f: root_files) {
      f->Close();
   }
 
   root_files.clear();
 
   return 0;
}
 
/* emacs
 * Local Variables:
 * tab-width: 8
 * c-basic-offset: 3
 * indent-tabs-mode: nil
 * End:
 */