File SIOLegacyReader.h

namespace podio

class SIOLegacyReader

#include <podio/SIOLegacyReader.h>

A SIO reader for reading legacy podio .sio files that have been written using the legacy, non Frame based I/O model.

This reader grants Frame based access to those files, by mimicking Frame I/O functionality and the interfaces of those readers.

NOTE: Since there was only one category (“events”) for those legacy podio files this reader will really only work if you try to read that category, and will simply return no data if you try to read anything else.

Public Functions

SIOLegacyReader()

~SIOLegacyReader() = default

SIOLegacyReader(const SIOLegacyReader&) = delete

SIOLegacyReader &operator=(const SIOLegacyReader&) = delete

std::unique_ptr<podio::SIOFrameData> readNextEntry(const std::string&)

Read the next data entry from which a Frame can be constructed.

In case there are no more entries left, this returns a nullptr.

NOTE: the category name has to be “events” in this case, as only that category is available for legacy files.

std::unique_ptr<podio::SIOFrameData> readEntry(const std::string&, const unsigned entry)

Read the specified data entry from which a Frame can be constructed In case the entry does not exist, this returns a nullptr.

NOTE: the category name has to be “events” in this case, as only that category is available for legacy files.

unsigned getEntries(const std::string &name) const

Returns the number of.

void openFile(const std::string &filename)

inline 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 available Frame categories in the current file(s)

Private Functions

bool readFileTOCRecord()

read the TOC record

void readCollectionIDTable()

Private Members

sio::ifstream m_stream = {}

std::vector<std::string> m_typeNames = {}

std::vector<short> m_subsetCollectionBits = {}

sio::buffer m_tableBuffer = {1}

The buffer holding the compressed CollectionIDTable.

unsigned m_tableUncLength = {0}

The uncompressed length of the tableBuffer.

std::shared_ptr<podio::CollectionIDTable> m_table = {nullptr}

unsigned m_eventNumber = {0}

SIOFileTOCRecord m_tocRecord = {}

podio::version::Version m_fileVersion = {0}

Private Static Attributes

static constexpr auto m_categoryName = "events"