podio::ROOTFrameReader Class Reference

#include <ROOTFrameReader.h>

Public Member Functions
	ROOTFrameReader ()=default
	~ROOTFrameReader ()=default
	ROOTFrameReader (const ROOTFrameReader &)=delete
ROOTFrameReader &	operator= (const ROOTFrameReader &)=delete
void	openFile (const std::string &filename)
void	openFiles (const std::vector< std::string > &filenames)
std::unique_ptr< podio::ROOTFrameData >	readNextEntry (const std::string &name)
std::unique_ptr< podio::ROOTFrameData >	readEntry (const std::string &name, const unsigned entry)
unsigned	getEntries (const std::string &name) const
	Returns number of entries for the given name.
podio::version::Version	currentFileVersion () const
	Get the build version of podio that has been used to write the current file.
std::vector< std::string_view >	getAvailableCategories () const
	Get the names of all the availalable Frame categories in the current file(s)
const std::string_view	getDatamodelDefinition (const std::string &name) const
	Get the datamodel definition for the given name.
std::vector< std::string >	getAvailableDatamodels () const
	Get all names of the datamodels that ara available from this reader.

Detailed Description

This class has the function to read available data from disk and to prepare collections and buffers.

Definition at line 44 of file ROOTFrameReader.h.

Constructor & Destructor Documentation

ROOTFrameReader() [1/2]

podio::ROOTFrameReader::ROOTFrameReader ( )

default

~ROOTFrameReader()

podio::ROOTFrameReader::~ROOTFrameReader ( )

default

ROOTFrameReader() [2/2]

podio::ROOTFrameReader::ROOTFrameReader ( const ROOTFrameReader &  )

delete

Member Function Documentation

currentFileVersion()

podio::version::Version podio::ROOTFrameReader::currentFileVersion ( ) const

inline

Get the build version of podio that has been used to write the current file.

Definition at line 76 of file ROOTFrameReader.h.

                                                 {
    return m_fileVersion;
  }

getAvailableCategories()

std::vector< std::string_view > podio::ROOTFrameReader::getAvailableCategories

(

)

const

Get the names of all the availalable Frame categories in the current file(s)

Definition at line 248 of file ROOTFrameReader.cc.

                                                                        {
  std::vector<std::string_view> cats;
  cats.reserve(m_categories.size());
  for (const auto& [cat, _] : m_categories) {
    cats.emplace_back(cat);
  }
  return cats;
}

getAvailableDatamodels()

std::vector< std::string > podio::ROOTFrameReader::getAvailableDatamodels ( ) const

inline

Get all names of the datamodels that ara available from this reader.

Definition at line 89 of file ROOTFrameReader.h.

                                                      {
    return m_datamodelHolder.getAvailableDatamodels();
  }

getDatamodelDefinition()

const std::string_view podio::ROOTFrameReader::getDatamodelDefinition ( const std::string &  name ) const

inline

Get the datamodel definition for the given name.

Definition at line 84 of file ROOTFrameReader.h.

                                                                           {
    return m_datamodelHolder.getDatamodelDefinition(name);
  }

getEntries()

unsigned podio::ROOTFrameReader::getEntries

(

const std::string &

name

)

const

Returns number of entries for the given name.

Definition at line 240 of file ROOTFrameReader.cc.

                                                                {
  if (auto it = m_categories.find(name); it != m_categories.end()) {
    return it->second.chain->GetEntries();
  }
 
  return 0;
}

openFile()

void podio::ROOTFrameReader::openFile

(

const std::string &

filename

)

Definition at line 196 of file ROOTFrameReader.cc.

                                                        {
  openFiles({filename});
}

openFiles()

void podio::ROOTFrameReader::openFiles

(

const std::vector< std::string > &

filenames

)

Definition at line 200 of file ROOTFrameReader.cc.

                                                                     {
  m_metaChain = std::make_unique<TChain>(root_utils::metaTreeName);
  // NOTE: We simply assume that the meta data doesn't change throughout the
  // chain! This essentially boils down to the assumption that all files that
  // are read this way were written with the same settings.
  // Reading all files is done to check that all file exists
  for (const auto& filename : filenames) {
    if (!m_metaChain->Add(filename.c_str(), -1)) {
      throw std::runtime_error("File " + filename + " couldn't be found");
    }
  }
 
  podio::version::Version* versionPtr{nullptr};
  if (auto* versionBranch = root_utils::getBranch(m_metaChain.get(), root_utils::versionBranchName)) {
    versionBranch->SetAddress(&versionPtr);
    versionBranch->GetEntry(0);
  }
  m_fileVersion = versionPtr ? *versionPtr : podio::version::Version{0, 0, 0};
  delete versionPtr;
 
  if (auto* edmDefBranch = root_utils::getBranch(m_metaChain.get(), root_utils::edmDefBranchName)) {
    auto* datamodelDefs = new DatamodelDefinitionHolder::MapType{};
    edmDefBranch->SetAddress(&datamodelDefs);
    edmDefBranch->GetEntry(0);
    m_datamodelHolder = DatamodelDefinitionHolder(std::move(*datamodelDefs));
    delete datamodelDefs;
  }
 
  // Do some work up front for setting up categories and setup all the chains
  // and record the available categories. The rest of the setup follows on
  // demand when the category is first read
  m_availCategories = ::podio::getAvailableCategories(m_metaChain.get());
  for (const auto& cat : m_availCategories) {
    auto [it, _] = m_categories.try_emplace(cat, std::make_unique<TChain>(cat.c_str()));
    for (const auto& fn : filenames) {
      it->second.chain->Add(fn.c_str());
    }
  }
}

Referenced by openFile().

operator=()

ROOTFrameReader & podio::ROOTFrameReader::operator= ( const ROOTFrameReader &  )

delete

readEntry()

std::unique_ptr< ROOTFrameData > podio::ROOTFrameReader::readEntry	(	const std::string &	name,
		const unsigned	entry
	)

Read the specified data entry from which a Frame can be constructed for the given name. In case the entry does not exist for this name or in case there is no data for this name, this returns a nullptr.

Definition at line 41 of file ROOTFrameReader.cc.

                                                                                                    {
  auto& catInfo = getCategoryInfo(name);
  catInfo.entry = entNum;
  return readEntry(catInfo);
}

Referenced by readEntry(), and readNextEntry().

readNextEntry()

std::unique_ptr< ROOTFrameData > podio::ROOTFrameReader::readNextEntry

(

const std::string &

name

)

Read the next data entry from which a Frame can be constructed for the given name. In case there are no more entries left for this name or in case there is no data for this name, this returns a nullptr.

Definition at line 36 of file ROOTFrameReader.cc.

                                                                                 {
  auto& catInfo = getCategoryInfo(name);
  return readEntry(catInfo);
}

---

The documentation for this class was generated from the following files:

• ROOTFrameReader.h
• ROOTFrameReader.cc