VROOTFile.cc

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#include <io/VROOTFile.h>

#include <utl/ErrorLogger.h>
#include <utl/SaveCurrentTDirectory.h>

#include <TFile.h>
#include <TTree.h>

#include <cstddef>
#include <iostream>
#include <string>

using namespace io;
using namespace utl;
using namespace std;


VROOTFile::VROOTFile(const string& filename, const Mode mode, utl::Branch* const b) :
  VEventFile(filename, mode, b)
{
  DefaultOpen(filename, mode);

  const int result = OpenROOTFile();

  if (result == -1) {

    const string error =
      "Unable to create in-memory image of ROOT file " + fFilename;
    throw utl::IOFailureException(error);

  } else if (result == -2) {

    const string error =
      "In-memory file image created corresponds to zombie ROOT file " + fFilename;
    throw utl::IOFailureException(error);

  }
}


VROOTFile::~VROOTFile()
{
  if (fFile) {
    if (fFile->IsOpen())
      fFile->Close();
    delete fFile;
  }
}


void
VROOTFile::Open(const string& filename, const Mode mode, utl::Branch* const /*b*/)
{
  DefaultOpen(filename, mode);

  const int ret = OpenROOTFile();

  if (ret < 0) {

    ostringstream error;
    error << "Cannot open root file: " << filename;
    throw utl::IOFailureException(error.str());

  }
}


int
VROOTFile::OpenROOTFile()
{
  Close();

  const string rootMode = GetRootMode(fMode);

  const SaveCurrentTDirectory save;
  fFile = TFile::Open(fFilename.c_str(), rootMode.c_str());

  if (!fFile)
    return -1;

  if (fFile->IsZombie())
    return -2;

  return 0;
}


void
VROOTFile::Close()
{
  if (fFile && fFile->IsOpen()) {

    if (fTree && fMode != eRead) {
      const SaveCurrentTDirectory save;
      fFile->cd();
      fTree->Write();
    }

    fFile->Close();
  }
}


int
VROOTFile::GetTree(const string& name)
{
  fTree = dynamic_cast<TTree*>(fFile->Get(name.c_str()));

  if (!fTree) {

    ostringstream fat;
    fat << "Cannot find Tree " << name;
    FATAL(fat);
    return -1; // TODO: make error handling for IO consistent: use exceptions

  }

  return 0;
}


string
VROOTFile::GetRootMode(const Mode mode)
{
  switch (mode) {
  case eNew:
    return "recreate";
  case eWrite:
    return "new";
  case eAppend:
    return "update";
  default:
    return "read";
  }
}