podio::SIOReader Class Reference

#include <SIOReader.h>

Inheritance diagram for podio::SIOReader:

Public Member Functions
	SIOReader ()
	~SIOReader ()=default
	SIOReader (const SIOReader &)=delete
SIOReader &	operator= (const SIOReader &)=delete
void	openFile (const std::string &filename) override
void	closeFile () override
void	readEvent () override
	Read all collections requested.
void	goToEvent (unsigned iEvent) override
std::shared_ptr< CollectionIDTable >	getCollectionIDTable () override
	Read CollectionIDTable from SIO file.
unsigned	getEntries () const override
	get the number of events available from this reader
bool	isValid () const override
	Check if file is valid.
podio::version::Version	currentFileVersion () const override
	Get the podio version with which the current file has been written.
void	endOfEvent () override
	Prepare the reader to read the next event.
Public Member Functions inherited from podio::IReader
virtual	~IReader ()=default
virtual CollectionBase *	readCollection (const std::string &name)=0
virtual std::shared_ptr< CollectionIDTable >	getCollectionIDTable ()=0
	Get CollectionIDTable of read-in data.
virtual GenericParameters *	readEventMetaData ()=0
	read event meta data from file
virtual std::map< int, GenericParameters > *	readCollectionMetaData ()=0
virtual std::map< int, GenericParameters > *	readRunMetaData ()=0
virtual unsigned	getEntries () const =0
	get the number of events available from this reader
virtual void	endOfEvent ()=0
	Prepare the reader to read the next event.
virtual bool	isValid () const =0
	Check if reader is valid.
virtual void	openFile (const std::string &filename)=0
virtual void	closeFile ()=0
virtual void	readEvent ()=0
virtual void	goToEvent (unsigned iEvent)=0
virtual podio::version::Version	currentFileVersion () const =0
	Get the podio version with which the current file has been written.

Detailed Description

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

Definition at line 30 of file SIOReader.h.

Constructor & Destructor Documentation

SIOReader() [1/2]

podio::SIOReader::SIOReader

(

)

Definition at line 15 of file SIOReader.cc.

                     :
    m_eventNumber(0),
    m_eventMetaData(std::make_shared<SIOEventMetaDataBlock>()),
    m_runMetaData(std::make_shared<SIONumberedMetaDataBlock>("RunMetaData")),
    m_collectionMetaData(std::make_shared<SIONumberedMetaDataBlock>("CollectionMetaData")) {
  auto& libLoader [[maybe_unused]] = SIOBlockLibraryLoader::instance();
}

~SIOReader()

podio::SIOReader::~SIOReader ( )

default

SIOReader() [2/2]

podio::SIOReader::SIOReader ( const SIOReader &  )

delete

Member Function Documentation

closeFile()

void podio::SIOReader::closeFile ( )

overridevirtual

Implements podio::IReader.

Definition at line 74 of file SIOReader.cc.

                          {
  m_stream.close();
}

Referenced by main().

currentFileVersion()

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

inlineoverridevirtual

Get the podio version with which the current file has been written.

Implements podio::IReader.

Definition at line 61 of file SIOReader.h.

                                                          {
    return m_fileVersion;
  }

Referenced by main().

endOfEvent()

void podio::SIOReader::endOfEvent ( )

overridevirtual

Prepare the reader to read the next event.

Implements podio::IReader.

Definition at line 107 of file SIOReader.cc.

                           {
  ++m_eventNumber;
  m_blocks.clear();
  m_inputs.clear();
}

Referenced by main().

getCollectionIDTable()

std::shared_ptr< CollectionIDTable > podio::SIOReader::getCollectionIDTable ( )

inlineoverridevirtual

Read CollectionIDTable from SIO file.

Implements podio::IReader.

Definition at line 50 of file SIOReader.h.

                                                                   {
    return m_table;
  }

getEntries()

unsigned podio::SIOReader::getEntries ( ) const

inlineoverridevirtual

get the number of events available from this reader

Implements podio::IReader.

Definition at line 54 of file SIOReader.h.

                                       {
    return m_tocRecord.getNRecords("event_record");
  }

Referenced by main().

goToEvent()

void podio::SIOReader::goToEvent ( unsigned  iEvent )

overridevirtual

Implements podio::IReader.

Definition at line 113 of file SIOReader.cc.

                                              {
  // If we are already past the desired event number, rewind to the start first
  if (eventNumber < (unsigned)m_eventNumber) {
    m_stream.clear();
    m_stream.seekg(0);
    m_eventNumber = 0;
  }
 
  sio::api::go_to_record(m_stream, "event_record");
  if ((eventNumber - m_eventNumber) > 0) {
    sio::api::skip_n_records(m_stream, eventNumber - m_eventNumber);
  }
  m_eventNumber = eventNumber;
 
  m_inputs.clear();
  m_blocks.clear();
}

isValid()

bool podio::SIOReader::isValid ( ) const

overridevirtual

Check if file is valid.

Implements podio::IReader.

Definition at line 103 of file SIOReader.cc.

                              {
  return m_stream.good();
}

Referenced by openFile().

openFile()

void podio::SIOReader::openFile ( const std::string &  filename )

overridevirtual

Implements podio::IReader.

Definition at line 62 of file SIOReader.cc.

                                                  {
  m_stream.open(filename, std::ios::binary);
  if (!this->isValid()) {
    throw std::runtime_error("File " + filename + " couldn't be found");
  }
  readCollectionIDTable();
 
  if (!readFileTOCRecord()) {
    reconstructFileTOCRecord();
  }
}

Referenced by main().

operator=()

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

delete

readEvent()

void podio::SIOReader::readEvent ( )

overridevirtual

Read all collections requested.

Implements podio::IReader.

Definition at line 78 of file SIOReader.cc.

                          {
  // recreate the blocks, since the contents are owned and managed by the
  // EventStore
  createBlocks();
 
  // skip possible intermediate records that are not event data
  sio::api::go_to_record(m_stream, "event_record");
 
  sio::record_info rec_info;
  sio::api::read_record_info(m_stream, rec_info, m_info_buffer);
  sio::api::read_record_data(m_stream, rec_info, m_rec_buffer);
 
  m_unc_buffer.resize(rec_info._uncompressed_length);
  sio::zlib_compression compressor;
  compressor.uncompress(m_rec_buffer.span(), m_unc_buffer);
  sio::api::read_blocks(m_unc_buffer.span(), m_blocks);
 
  for (size_t i = 1; i < m_blocks.size(); ++i) {
    auto* blk = static_cast<podio::SIOBlock*>(m_blocks[i].get());
    m_inputs.emplace_back(blk->getCollection(), m_table->names()[i - 1]);
  }
 
  m_lastEventRead = m_eventNumber;
}

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

• SIOReader.h
• SIOReader.cc