rootutils.h

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// SPDX-License-Identifier: LGPL-3.0-or-later
// Copyright (C) 2022 Sylvester Joosten, Wouter Deconinck
 
#ifndef PODIO_ROOT_UTILS_H
#define PODIO_ROOT_UTILS_H
 
#include "podio/podioVersion.h"
#include "podio/CollectionBase.h"
#include "podio/CollectionBranches.h"
 
#include "TBranch.h"
#include "TClass.h"
 
#include <vector>
#include <string>
 
namespace podio::root_utils {
// Workaround slow branch retrieval for 6.22/06 performance degradation
// see: https://root-forum.cern.ch/t/serious-degradation-of-i-o-performance-from-6-20-04-to-6-22-06/43584/10
template<class Tree>
TBranch* getBranch(Tree* chain, const char* name) {
  return static_cast<TBranch*>(chain->GetListOfBranches()->FindObject(name));
}
 
inline std::string refBranch(const std::string& name, size_t index) {
  return name + "#" + std::to_string(index);
}
 
inline std::string vecBranch(const std::string& name, size_t index) {
  return name + "_" + std::to_string(index);
}
 
 
inline void setCollectionAddresses(podio::CollectionBase* collection, const CollectionBranches& branches) {
  auto buffers = collection->getBuffers();
  auto data = buffers.data;
  auto references = buffers.references;
  auto vecmembers = buffers.vectorMembers;
 
  if (data) {
    branches.data->SetAddress(data);
  }
 
  if (references) {
    for (size_t i = 0; i < references->size(); ++i) {
      branches.refs[i]->SetAddress(&(*references)[i]);
    }
  }
 
  if (vecmembers) {
    for (size_t i = 0; i < vecmembers->size(); ++i) {
      branches.vecs[i]->SetAddress((*vecmembers)[i].second);
    }
  }
}
 
}
 
#endif