The next generation of VCS has a clear target ahead of them: making branching and merging easier. Until recently, Subversion was dominating the world of Version Control Systems, but now, Distributed Version Control Systems are growing in popularity and everywhere you go you hear about Git or Mercurial, and how they make branching and merging a breeze. But the Subversion team isn't going down quietly, they have a new weapon: the 1.5 version. Learn about the next generation of Version Control Systems is planning to solve your problems.

1. 1 Your next Version Control System Gilad Garon December 18th 2008

2. Agenda Introduction Branching Merging Subversion 1.5 Distributed Version Control 2

3. Introduction What’s every VCS user worst nightmare? Nope. It’s… 3

4. Agenda Introduction Branching Merging Subversion 1.5 Distributed Version Control 4

5. Development Cycle Our repository layout should behave like our development cycle: Development Phase Testing Phase Release Final Product Our VCS should accommodate us and not the other way, no matter what’s our development process. 5

6. Single Development Line One branch holds all phases of the develop cycle. 6

7. Development Line with Support Line 7 Pros Cons

8. Development Line with Support Line One branch holds our development code. A second branch holds our production code for continued support. 8

9. Development Line with Support Line 9 Pros Cons

10. Three Level Build A classic layout for a three phase development cycle. Release candidates are for the testing phase and support phase. The production branch is sterile. 10

11. Development Line with Support Line 11 Pros Cons

12. Multiple Feature Support Build #1 Feature branches allow for even more code separation on complex projects 12

14. Branching is good for you Branches are great for code separation. Branches are cheap Branches are easy to createSo, what’s the catch? 15

15. Agenda Introduction Branching Merging Subversion 1.5 Distributed Version Control 16

16. Merging What the?! Override everything! Seems Familiar? 17

17. Why merges are hard? Requires knowledge of the code Resolving conflicts by hand takes time Large projects require some planning Can cause logical bugs which aren’t easily detected 18

18. Making merges easier Merge daily! Let the VCS do the merge for you Don’t merge at the last minute, allocate merging time in your time table. Keep tabs on your code, keep notes on your changes. 19

20. No more revision calculations

21. Cherry Pick your changes

22. See incoming changes

23. Refactor code without fear My Hero! 20

25. Merges are hard?

26. Daily merges helps?

27. Automatic merges are dangerous?

28. Merging takes days of preparation?21

29. Agenda Introduction Branching Merging Subversion 1.5 Distributed Version Control 22

30. What’s New? Merge tracking Sparse checkouts Interactive conflict resolution Changelist support Speed improvements, cancellation response improvements Bug Fixes 23

31. Merge Tracking Create a branch Work on your branch Update your branch with trunk’s changes svn copy http://yourserver.com/svn/project-x/trunk http://yourserver.com/svn/project-x/branches/feature-z -m "Creating a feature branch of /project-x/trunk." svn checkout http://yourserver.com/svn/project-x/branches/feature-z… work …svn commit - m “committing my work." svn merge http://yourserver.com/svn/project-x/trunk --- Merging r20 through r45 into '.': U GridView.java 24

32. Merge Tracking What has been merged so far? Which changes are available from trunk? svn propget svn:mergeinfo . /trunk:20-45 # or svn mergeinfo http://yourserver.com/svn/project-x/trunk r20r21…r44r45 svn mergeinfo http://yourserver.com/svn/project-x/trunk --show-revs eligible r46r47 25

33. Merge Tracking Merging back your branch: What’s the catch? No support for renames moves Mergeinfo is sometimes generated when no merge was done $ cd /workspace/project-x/trunk$ svn merge --reintegrate http://yourserver.com/svn/project-x/branches/feature-z--- Merging differences between repository URLs into '.': … changes list …# build, test, verify, ... $ svn commit -m “Merging feature-z back into trunk!" 26

34. More New Features Sparse checkouts Interactive conflict resolution Changelist support $ svn checkout URI --depth=[empty,files,immediates,infinity]# command support - checkout, switch, update, status, info $ svn up U project-x/trunk/GridView.javaConflict discovered in 'project-x/trunk/GridView.java'.Select: (p) postpone, (df) diff-full, (e) edit, (s) show all options: $ svn changelist bug-fix-1 GridView.javaPath 'GridView.java' is now a member of changelist 'bug-fix-1'.$ svn status --- Changelist ‘bug-fix-1': M GridView.java 27

35. Upgrading to Subversion 1.5 Server Backup everything Install Subversion 1.5 Server Upgrade existing repositories with: Populate indexes (Optional): Upgrade clients Pray to god 28 $ svnadmin upgrade REPOS_PATH $ svn-populate-node-origins-index REPOS-PATH

36. TortoiseSVN 1.5 29 TortoiseSVN is upgraded to support Subversion 1.5 The Merge process is simplified and merge tracking is supported The repository now more resembles the Windows explorer Changelist support is supported Hook Scripts and Issue Trackers are supported

37. TortoiseSVN 1.5 Merge 30

38. New Feature Compatibility Table 31

39. Agenda Introduction Branching Merging Subversion 1.5 DistributedVersion Control 32

40. What is DVCS? Distributed VCS does NOT mean the physical distribution of the repository over several machines. Distributed VCS means the repository is located on your machine. 33

41. Terminology In DVCS we… Do not check out from the repository, we clonethe repository. Do not update our working copy, we pullchanges from other repositories. Do not check in our changes,we pushchanges to other repositories. 34

42. Advantages You are the repository Performance, no network overhead. Work offline, work where ever you want. Experiment, no commit rights required. Local Commits, the repository is in your workspace. Flexible repository topology 35

43. Disadvantages But… Sparse checkouts are not fully supported if at all. Most vendors do not support branching, you must clone. Merge Tracking needs to mature a bit. More suited to Open Source projects than commercial. 36

44. Centralized Workflow 37

45. Decentralized Workflow 38

46. Decentralized with shared mainlineWorkflow 39

47. Decentralized with GatekeeperWorkflow 40

49. Invented by Linus Torvalds to replace BitKeeper

50. Toolkit design

51. Used in - Linux Kernel, VLC, Ruby On Rails, Fedora, Android

52. IDE Support - Eclipse, NetBeansIntelliJ (Native)Subversion is the devil, use Git. 41

53. Git Shell 42

54. Gitk 43

55. Git Pros & Cons 44 Pros Cons

57. Started as a branch of Arch

58. Sponsored by Canonical (Ubuntu)

59. Used in - Ubuntu, MySQL, Drupal, APT, Linux Foundation

60. IDE Support - Eclipse, IntelliJ (Native)45

61. Tortoise Bazaar 46

62. Bazaar Pros & Cons 47 Pros Cons

64. Very Similar to Subversion

65. Adopted by Sun Microsystems

66. Used in - Mozilla, NetBeans, OpenJDK, OpenSolaris

67. IDE Support - Eclipse, NetBeans,IntelliJ48

68. Mercurial Serve 49

69. Tortoise Mercurial 50

70. Mercurial Pros & Cons 51 Pros Cons

71. Comparison 52

72. Conclusion And the Winner is? Experiment with the tools Choose the tool which works with your workflow 53

73. References Subversion Home Page: http://subversion.tigris.org/ Tortoise: http://tortoisesvn.tigris.org/ SVNKit: http://svnkit.com/ Eclipse Plug-in: http://subclipse.tigris.org/ NetBeans Plug-in: http://subversion.netbeans.org/ Git Home Page: http://git.or.cz/ msysgit (Git Windows) : http://code.google.com/p/msysgit/ Eclipse Plug-in: http://git.or.cz/gitwiki/EclipsePlugin NetBeans Plug-in: http://code.google.com/p/nbgit/ 54

74. References Mercurial Home Page: http://www.selenic.com/mercurial/wiki/ TortoiseHG: http://www.selenic.com/mercurial/wiki/index.cgi/TortoiseHg Eclipse Plug-in: http://www.vectrace.com/mercurialeclipse Bazaar Home Page: http://bazaar-vcs.org/ IDE Plug-ins: http://bazaar-vcs.org/IDEIntegration 55

75. Thank You ! 56