1. Where Does This Code Come from and Where Does It Go?
- Integrated Code History Tracker for Open Source Systems –
Katsuro Inoue, Yusuke Sasaki, Pei Xia, and Yuki Manabe
Osaka University Osaka, Japan {inoue, peixia,
Software Engineering (ICSE), th International Conference on

2. Outline
Introduction
Approach
Processes
Experiment
Summary
Future work

3. Introduction
To reuse an open source code file
We do not know much about the original project
If we could safely and effectively reuse it?
How to make a decision to reuse it?

4. Approach

5. Approach

6. Processes

7. Experiment - Texture.java
1,600 LOC Java File
Define a graphic texture object
Developed by jMonkeyEngine
Popularly used by many 3D games
Input Query Q
qc : overall source code
qa : the file name“texture.java”

8. Experiment - Texture.java

9. Experiment - Texture.java

10. Experiment - Texture.java

11. Experiment - Texture.java
Texture.java code evolves along with the project progress
Each version of Texture.java is copied to many other projects,which are identified as similar files in Clusters A, B, and C
Cluster C, there are 6 file exactly the same as the query code
One outlier project #25

12. Experiment – kern_malloc.c
Is a C function
Allocates a specified-size memory block in th kernel
Fairly old
Taken over and maintained by many other various projects
Input Query Q
qc : overall source code
qa : the file name“texture.java”
No SPARS/R

13. Experiment – kern_malloc.c

14. Experiment – kern_malloc.c

15. Experiment – kern_malloc.c

16. Experiment – kern_malloc.c
The cover ratio of the output results diverges along the time scale
No clear cluster of similar results
Many variations of different code fragments
Many small changes among the projects
All of these results are under BSD License
Overview the evolution of a core part of Unxi OS kernel code

17. Experiment - SSHTools SSHTools Input Query Q
A suite of java SSH applications
Providing a java SSH API,terminal
Input Query Q
qc : 339 files of the latest version 0.2.9
qa : file names
Ignoring some tiny sized files
A threshold of the cover ration 0.4

18. Experiment - SSHTools

19. Experiment - SSHTools

20. Experiment - SSHTools
Many different ancestor projects
SSHTools is a collection of various tools
Donated by different projects
Their licenses and copyrights had been modified

21. Future work
Improve the performance and usability
Explore a unified approach of local repositories and Internet repositories
Use the search results as the new searche queries
Tracking such code chain

22. Thanks！ Q&A