Class podio::ArrowReader

class ArrowReader : public podio::ReaderCommon 

Arrow backend reader for PODIO.

Reads data from a directory structure containing one Parquet file per category and a metadata.json file containing metadata for reading.

Public Functions

void openFile(const std::string &directory)

Open the passed directory for reading.

Parameters:: directory – The path to the directory to read from
Throws:: std::logic_error – if a directory has already been opened with this reader

std::unique_ptr<podio::ArrowFrameData> readNextEntry(std::string_view name, const std::vector<std::string> &collsToRead = {}): Read the next entry for the given category.

std::unique_ptr<podio::ArrowFrameData> readEntry(std::string_view name, size_t index, const std::vector<std::string> &collsToRead = {}): Read the specific entry for the given category.

size_t getEntries(std::string_view name) const: Get the number of entries for a category.

inline podio::version::Version currentFileVersion() const

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

inline std::optional<podio::version::Version> currentFileVersion(std::string_view name) const

Get the (build) version of a datamodel that has been used to write the current file.

Parameters:: name – The name of the datamodel
Returns:: The (build) version of the datamodel if available or an empty optional

inline const std::string_view getDatamodelDefinition(std::string_view name) const

Get the datamodel definition for the given name.

inline std::vector<std::string> getAvailableDatamodels() const

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

inline std::vector<std::string_view> getAvailableCategories() const

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