This document provides an overview of Git and its features. It discusses source control management (SCM) and version control systems (VCS). It describes the different SCM models including local, centralized, and distributed systems. Key aspects of Git are summarized like its use of snapshots instead of differences, three states of files, and its speed and integrity. Branching, merging, and rebasing functions are explained. The document also proposes a workflow for using Git that incorporates features, develop, master, and hotfix branches.

1. Git
Daniele Giunchi

2. Summary
• SCM, VCS Terminology
• SCM Models
• History
• Git Specs
• Branching
• Merging
• Rebasing
• Github
• Git as Workflow Generator
• Proposed Workflow for B3C
November 2011 Presentation B3C

3. SMC, VCS Terminology
• SMC -> Source Control Management
• VCS -> Version Control System
• CVS -> Concurrent Version System
(App)
• SVN -> Subversion (App)
• Git -> is Git! (App)
November 2011 Presentation B3C

4. Let’s dive into Git!
no git user git user
November 2011 Presentation B3C

5. SCM Models
• Local Control Version Systems
• Centrilized Control Version Systems
• Distributed Control Version Systems
November 2011 Presentation B3C

6. Local Control Version Systems
November 2011 Presentation B3C

7. Local Control Version Systems
• A directory in your filesystem!
• A database
• SCCS (1972)
• RCS Revision Control System (1982)
• PVCS (1985)
November 2011 Presentation B3C

8. Centrilized Control Version Systems
November 2011 Presentation B3C

9. Centrilized Control Version Systems
• CVS (1990)
• SVN (2000)
• ClearCase (1992)
• Visual SourceSafe (1994)
• Perforce (1995)
• Rational Team Concert (2008)
November 2011 Presentation B3C

10. Distributed Control Version Systems
November 2011 Presentation B3C

11. Distributed Control Version Systems
Git (2005)
Mercurial (2005)
Bazaar (2011)
Bitkeeper (1998)
November 2011 Presentation B3C

12. History
• Linux kernel (1991 - …)
• Free Lic. Bitkeeper (2oo2 – 2005)
• Git birth (2005)
Author : Linus Torvalds
Written: C , Bourne Shell, Perl
Licence: GNU GPL
November 2011 Presentation B3C

13. Hail Linus!
November 2011 Presentation B3C

14. Current Maintenance Chief!
Junio Hamano
November 2011 Presentation B3C

15. Characteristics
• Speed
• Simple design
• Strong support for non-linear development
(thousands of parallel branches)
• Fully distributed
• Able to handle large projects
• Portable
Look at http://whygitisbetterthanx.com
November 2011 Presentation B3C

16. Git Specs: Snapshots Not Differences
November 2011 Presentation B3C

17. Git Specs: Snapshots Not Differences
November 2011 Presentation B3C

18. Git Specs: Speed? Integrity?
• Git operates locally
• Git has integrity: SHA1
Secure Hash Algorithm (40 ASCII chars)
1f8a690b7366a2323e2d5b045120da7e93896f47
1f8a690
November 2011 Presentation B3C

19. Git Specs: The Three States
• File can be committed, modified, and staged
November 2011 Presentation B3C

20. Git Specs: Recording Changes
November 2011 Presentation B3C

21. Git Specs: Add/Commit/Push
November 2011 Presentation B3C

22. Git Specs: A GUI please!!!!
November 2011 Presentation B3C

23. How Git storages data
November 2011 Presentation B3C

24. After some commits…
November 2011 Presentation B3C

25. …and now define “Branch”
• A branch in Git is simply a lightweight movable pointer to one
of these commits.
November 2011 Presentation B3C

26. …and now Branch!
November 2011 Presentation B3C

27. … need a pointer to the snapshot!
November 2011 Presentation B3C

28. … and change the current branch…
November 2011 Presentation B3C

29. … suppose we achieve this graph …
November 2011 Presentation B3C

30. … and then commit into master…
November 2011 Presentation B3C

31. Toward The Merge
November 2011 Presentation B3C

32. Toward The Merge
November 2011 Presentation B3C

33. Toward The Merge
November 2011 Presentation B3C

34. Toward The Merge
November 2011 Presentation B3C

35. The Merge! Fast Forward Merge…
November 2011 Presentation B3C

36. Toward another Merge…
November 2011 Presentation B3C

37. Toward another Merge…
November 2011 Presentation B3C

38. The Merge! Three-way Merge…
November 2011 Presentation B3C

39. Rebase … What the hell ????
November 2011 Presentation B3C

40. OK…stop with Theory
November 2011 Presentation B3C

41. Github: base repository
November 2011 Presentation B3C

42. Git as Workflow Generator
• Git has access policies for the repositories
• Easy creation of branches
=> Creation of a Workflow
November 2011 Presentation B3C

44. B3C Workflow
• develop branch
• master branch
• feature/topic branches
• release branches
• hotfix branches
November 2011 Presentation B3C

45. Workflow Model
November 2011 Presentation B3C

46. master - develop
November 2011 Presentation B3C

47. Feature branches
November 2011 Presentation B3C

48. Hotfix branches
November 2011 Presentation B3C

49. References
• http://git-scm.com/
• http://www.ndpsoftware.com/git-cheatsheet.html
• http://gitimmersion.com/
• ProGit
November 2011 Presentation B3C

50. Coming soon… Hands on session!
November 2011 Presentation B3C