Review code evolution history in OSS universe

Software evolves all the time because of the changing requirements, in particular, in the diverse Internet environment. Evolution history recorded in software repositories, e.g., Version Control Systems, reflects people's software development practice. Exploring this history could help practitioners to reuse the best practices therefore improve productivity and software quality. Because of the difficulty of collecting and standardizing data, most existing work could only utilize small project set. In this study, we target the open source software universe to build a universal code evolution model for large-scale data. We consider code evolution from two aspects: code version changing history in a single project and code reuse history in the whole universe. In the model, files/modules are built as nodes, and relations (version change or reuse) between files/modules are built as connections. Based on the model, we design and implement a code evolution review framework, i.e., Code Evolution Reviewer (CER), which provides a series of data interfaces to review code evolution history, in particular, code version changing in single project and code reuse among projects. Further, CER could be utilized to explore best practices across large-scale project set.