SVN A Powerful Version Control Tool

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SVNA Powerful Version Control Tool
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Project Development Process

• I want to design
• Start working (very hard)
• It seems to work!
• Adding additional functionality
• Adding debugging procedures
• Adding functions for temporary usage
• _at_!_at_
• Where is my working version??? gt_lt

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Self solution (?????)

• Create multiple copies
• v1, v2, v3,
• v0401, v0403, v04031530,
• vdebug, vtest, vtcp, vtcpv2,
• What do these number mean??? gt_lt
• WRITE A VERY CLEAR README FILE
• SPEND A LOT OF DISK SPACE

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It gets worse with multiple people

• I will edit it tonight. Dont touch it!
• Did you change anything?
• Wheres the current working version?
• Gosh! We edited it at the same time!
• What have you done? It doesnt work now!
• Who change this file?
• _at__at_!
• People getting angry on each other \_/

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Whats the problem?

• Lack of version control and management
• Lack of a central repository
• Lack of managing multi-user file access
• SVN is for this sort of problems
• And we have set it up for you!

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Whats SVN?

• It gives every change in the repository a version
  number
• It records every version
• Handles version conflict

Figure 1.1. A typical client/server system
From http//svnbook.red-bean.com/nightly/en/svn-bo
ok.pdf, pg 23
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Using SVN

• Create a repository
• Import files
• Checkout files / update files
• Editing
• Commit

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Single user

• It serves as a versioned backup system
• I find out my new version has big problems and I
  dont want it anymore
• You can revert to previous versions
• I work across many computers and I always need to
  spend time copying files (and make sure theyre
  the same)
• You can checkout the latest version from the
  repository
• I always carefully backup my files
• You dont need to because theyre all in SVN
• Im developing a new function but I want my
  working version to be still there
• OK. You need BRANCH AND TAG

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Branches and Tags

• Trunk main files
• Branches developing functions/debugging
• Tags release version

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Merge

• SVN lists the difference between two files
• You can determine which one you want
• If theres no conflict, SVN will automatically
  add the two files into one

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Multi-user
http//openfoundry.org/
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Update and Conflict

• Update your files to make sure you are using the
  latest version
• If theres a difference between you local file
  and the repository, a conflict will be sent.
• You have to resolve the conflict before
  committing your version

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Do all the problems still exist?

• I will edit it tonight. Dont touch it!
• No problem. Just edit it. You will see the
  changes.
• Did you change anything?
• Find it out yourself in the SVN log
• Wheres the current working version?
• Checkout by yourself from the SVN repository!

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Do all the problems still exist?

• Gosh! We edited it at the same time!
• SVN will help you find out all the differences
  and help you merge them
• What have you done? It doesnt work now!
• See the log! And revert to the working version!
• Who change this file?
• Everything is in the log!

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When will you need it

• As long as you have some ongoing projects
• For sensor net group
• You HAVE to use it for the large code sharing in
  the group
• For paper writing
• Strongly suggest. Paper writing generates the
  most complicated versioning in very short time.

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A good example

• Te-Yuan, Ahey, and I were working on a paper
• We created 70 versions one night
• We edited 8 files simultaneously
• I dont believe we can make the paper deadline
  without using SVN

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Demo

• If we still have time
• You can access SVN locally in unix, via HTTP, and
  vis SSH.
• On windows? Tortoise SVN
• Right click your mouse and access SVN

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Checkout files

• svnssh//han_at_nslab.ee.ntu.edu.tw/home/svn/repos/s
  ensys08
• Its ssh!
• Need an account on the webserver
• Need to type password
• Password-free use pageant and puttygen
• Ask google!

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Editing

• Change the file content
• In the meantime someone else also edit
• Create a new file
• Dont forget to add it into the repos

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Commit

• Conflict?
• Resolve it!

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It takes time to learn a new software

• We are all new to it and feel free to discuss!