Download - SVN Tool Information : Best Practices
What is version control? Version management allows you to control and monitor
changes to files− What changes were made?− Revert to pervious versions− When were changes made − What code was present in release 2.7?
Earliest tools were around 1972 (SCCS) Older tools – RCS, CVS, Microsoft Source Safe, PVCS
Version Manager, etc… Current tools – Subversion, Mercurial, Git, Bazaar
We will use subversion (svn) Why?
Because it’s popular It’s well supported
− IDEs - Netbeans, Eclipse − Numerous GUI tools− Command line− XP Dev has support for it (you will use this for your semester
projects)
subversion concepts checkout – get a local copy of the files
− I have no files yet, how do I get them? add – add a new file into the repository
− I created a new file and want to check it in commit – send locally modified files to the repository
− I’ve made changes, how do I send them to the group? update – update all files with latest changes
− Other people made changes, how do I get them? tag / branch – label a “release”
− I want to “turn in” a set of files
Creating a new repository Command Line:
− Open command prompt− Go to a directory where you want your files to be stored− svn checkout <<location>>/svn/<<your project>>/
GUI Mac OSX SCPlugin− Adds commands to right-click menu in Finder
GUI Windows Tortoise SVN− Adds commands to right-click menu in Explorer
How to Use Version Control
checkout (first time)
(do some work, test)
update
commit
(do more work, test)
serverclient
send current revision ( n )
update your local copy with any changes in the repo.
save your changes and log entry
check statusany changes since revision n?
(resolve conflicts)
tags
branches
trunk
Project 1
Root
Project 2
Subversion Repository Layout
tags
branches
trunk
tags
trunk
Project 1
Repository parent dir
Project 2
tags
trunk
One repository, many projects One project per repository
branches
branches
Subversion "repository" Typically one "repository" per project. Server can have an unlimited number of
"repositories".
/var/svn/kuclock
revision 1(initial repo structure)
revision 2
revision 3
revision 3:
content diffs
author
date
reason for change (comment)
revision 4
"KUClock" Project Repository
revision 2:
initial project check-in
...etc...
Revision numbers
0 1 2 3
Revision number is increased for every transaction that changes the repository.
Properties of a Repository History of all changes to files and directories.
− you can recover any previous version of a file− remembers "moved" and "deleted" files
Access Control− Read / write permission for users and groups− Permissions can apply to repo, directory, or file
Logging− author of the change− date of the change− reason for the change
URLs and Protocols
http://myhost.com:port/path/to/repository
Protocol:
svn
svn+ssh
http
https
file
Host name or IP address
127.0.0.1
localhost
host:8443
optional port number
Repository
relative path
(1) Check Out using TortoiseSVN
Using Windows Explorer, right-click in a directory.
If not sure of path to check-out then use Repo-browser first.
In Repo-browser, right-click on folder or file you want to check-out.
(1) Check out using Eclipse
Many ways to do it. Here is a simple way:
1. Switch to "SVN Repository Exploring Mode".
2. Right click and choose New => Repository Location
3. Enter URL and (optional) authentication info.
(1) Check out using Eclipse Now you can browse the repository. Choose the part you want to check-out
(usually "trunk") Right click and choose "Check Out as..."
("Check Out as..." gives you a chance to change local project name if you want.)
Merging From a Branch
• What’s with the bug you've fixed on the bug-fix-branch?
• What about your current development?• You have to merge the
changes made in the branchback to the main line.
RELEASE 1.0.0
BUGFIX_BRANCH
Merge back
267
RELEASE 1.0.1
Merge From a Branch via CLI
You can merge the changes from the branch into your current working copy with the following command:
svn merge -r 267:HEAD branchnamebranchname
(1) The Subversion “merge”-command.(2) The revision in which we created the branch (267) and HEAD
for the complete branch.(3) The branch-name you like to merge into your current
working copy.
Merge From a Branch via CLI
You can find the revision number when the branch was created using the command:
svn log --verbose --stop-on-copy branchnamebranchname
(1) The Subversion “log”-command.(2) Print out much information (verbose).(3) Stop the log-output at the revision the branch was copied. (4) The branch-name you like to merge into your current
working copy.
Merge Tracking
Merge tracking:
• Subversion does notnot have any function to track merges that have already been done,i.e., to prevent you to merge a branch a second time.
• You have to do it yourself!
•Example: after merging, create a README-merged file in the branch stating that it was merged into trunk revision r99.
From the technical view branch and tag are the same.
BUT:
• The intention of a tag is that it should be used as read-only area whereas a branch is used to continue development (interim code, bug-fixing, release candidate etc.).
• Technically you can use a tag to continue development and check in etc. but you shouldn’t do it.
• So in other words the difference between a tag and a branch is just an agreement.
Merge Warning
Developer Branches
• Separation of team members can be realized with branches.
• One branch per team member or several members on a branch - the decision is based on the size of the teams.
Member 2
Main line
Member 1
Developer Branches
• Advantages using branches for team work:•No changes during development on the main line
needed => Code stability.
•Every team member can work in its own environment.
• Disadvantages:•Sometimes the mainline and the branch will diverge if
the branch lives too long.