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

ArrowReader()

Create an ArrowReader.

void openFile(const std::string &directory)

Open the passed directory for reading.

Parameters:

directory – The path to the directory to read from

~ArrowReader() = default

ArrowReader(const ArrowReader&) = delete

ArrowReader &operator=(const ArrowReader&) = delete

ArrowReader(ArrowReader&&) = delete

ArrowReader &operator=(ArrowReader&&) = delete

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.

Returns:

The podio build version

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.

Parameters:

name – The name of the datamodel

Returns:

The high level definition of the datamodel in JSON format

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

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

Returns:

The names of the datamodels

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

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

Returns:

The names of the available categories from the file