A new type of smart pointer for data object reference both in memory and in root files

Abstract

Based on ROOT framework, we develop a new mechanism named as SmartRef for event data correlations in offline data processing of High Energy Physics experiments. SmartRef uses the Universally Unique Identifier in ROOT to handle correlations between event data objects, both in memory and in ROOT files. It also provides a lazy-loading functionality to speed up event selection processes and simplify data input system. We have applied SmartRef to the JUNO offline software and used it as a test-bed. The test results show that SmartRef provides a significant improvement in event selection processes.