PODIO: recent developments in the Plain Old Data EDM toolkit

Abstract

PODIO is a C++ toolkit for the creation of event data models (EDMs) with a fast and efficient I/O layer. It employs plain-old-data (POD) data structures wherever possible, while avoiding deep object-hierarchies and virtual inheritance. A lightweight layer of handle classes provides the necessary highlevel interface for the physicist. PODIO creates all EDM code from simple instructive YAML files, describing the actual EDM entities. Since its original development PODIO has been very actively used for Future Circular Collider (FCC) studies. In its original version, the underlying I/O was entirely based on the automatic streaming code generated with ROOT dictionaries. Recently two additional I/O implementations have been added. One is based on HDF5 and the other uses SIO, a simple binary I/O library provided by LCIO. We briefly introduce the main features of PODIO and then report on recent developments with a focus on performance comparisons between the available I/O implementations. We conclude with presenting recent activities on porting the well-established LCIO EDM to PODIO and the recent EDM4hep project.

EDM4hep and podio - The event data model of the Key4hep project and its implementation

“…To free the users from the implementation details all code is automatically generated from a high level description in YAML format (see section 3.2). In this section we will only give a brief introduction to the general design principles [8,9] and instead focus on the most recent developments.…”

Key4hep: Status and Plans

“…The EDM4hep event data model is based on LCIO [8], successfully used in the linear collider community for more than 15 years, and on FCC-EDM [9], combining the best of the two approaches. It is implemented, using the PODIO [2,5] EDM-toolkit.…”

“…The Key4hep project aims at creating a complete turnkey software stack for detector optimisation and performance studies for future experiments. Since the last CHEP conference [1,2] much progress has been made in this project. The vision of Key4hep is to connect and extend individual packages from event generation to simulation and reconstruction into a complete data processing framework.…”

Review and outlook of accelerator-related codes and their interplay with the experiments software

“…Finally, it has to allow multi-paradigms for analysis, with C++ and Python at the same level. The strategy to meet these challenging requirements has been to adopt solutions developed for LHC, such as the Gaudi framework [44] and to look at ongoing common projects; among the latter, it is worth mentioning those developed under the AIDA EU R&D effort [45]: podio [46], used to define the event data model, and dd4hep [47], used for the geometrical description of all the elements relevant for the physics measurements, i.e. the sensitive and passive elements of the sub-detectors, supports, magnet and elements of the interaction region affecting the detector performance, such as the beam pipe and other elements which can scatter or produce particle debris in the detector.…”