Svn Usage Best Practices 090611150004 Phpapp02

8/9/2019 Svn Usage Best Practices 090611150004 Phpapp02

1/25

Source control

usingSVN

Prepared by

Ashraf Fouad


2/25


3/25

What source code control (SCC)? What:

Like shared network drive, but controlling access to filesbetween team members.

Merging different versions of code modified by severaldevelopers on text based level difference.

Tracking changes (viewing history).

Provide backup / restore points (short/long) term undo.

Provide branching / Merging.

Provide synchronization / locks / notifications. Provide HTTP / remote access.

Not for teams only even a single developer benefit from SCC as itmakes backup of different versions of source code.


4/25

Why source code control (SCC)? Why:

Shared network is not handling several developers accessingsame file.

Avoid using vague words that always change as latest, final,pre-final, v1, or dates to file that will prevent them of

compiling.

Keeping several versions for code for several reasons:

Product versions, its patches.

Maintain customization of product for several clients.

Allow the freedom to experiment or make Proof ofconcept without fear of losing control over code.

Some surveys indicate that 70% of software teams doesn't useSCC, I can't imagine how they cope ==> At the end it will be

your call to decide, although I don't think you can survive ;)


5/25

Known SCC software

CVS (Concurrent Versions System).

Microsoft Visual SourceSafe.

SVN (Subversion).

IBM Rational ClearCase.

Borland StarTeam.

This presentation is dedicated for centralized source code control,we are not discussing distributed repository architecture.

The naming convention is not always the same for all SCCsoftware, the naming convention used here will be for SVN.

In most companies using SCC, it is not only used for code, butalso, requirements, analysis, design, test scenarios, etc...


6/25

Why SVN? Powerful with command line interface.

Free / open source.

Availability of free client software / Plugin for most known IDEs.

SVN is simpler than CVS by eliminating some not commonly

used functionality. Faster.

DB based not file based.

Customized attributes to be attached to files.

Automatically handles all file types without instructions.

Support Folder / File rename & copies maintaining the history.


7/25

Sites / Required software Official site: SVN

Free server edition:VisualSVN Server

Free GUI client:

Eclipse Plugin (Subclipse).

Standalone free client most famous TortoiseSVN.

Standalone free / commercial SmartSVN.

Lots of sites offering hosting SVN (Offering SVN) (Free /Commercial).


8/25


9/25

Basic life cycle (Edit-Merge-Commit)

No Rev

Rev 1

Rev 1 Modified

Rev 2

Repository

Working folder

Merged


10/25

Basic life cycle (Edit-Merge-Commit) (cont.) The following rules applies:

Files in the working folder are all writable.

Nobody knows who is editing the files.

While developer commits, he is responsible for ensuring that

his changes were made against the latest version inrepository.

This life cycle is risky in the manner that the merge step maybe tedious or cause problems. However, the acceptance of this

risk rewards us with a concurrent development style.

Merge is only required when team members are working inparallel in the same file, usually it is better to do the merge

manually rather than doing automatic merge supplied bydifferent client tools.


11/25

Merge example

Rev 4

Repository

Dev 2Working folder

Dev 1Working folder

Rev 5

Rev 5

Rev 5

Modified 5by dev 1

Modified 5by dev 2

Rev 6

Modified 5By dev 2

merge withRev 6

Rev 7


12/25

Client setup / connectivity for TortoiseSVN TortoiseSVN client (windows installation msi):

Install with full integration.

You will need to restart after installation.

In order to connect:

Create a folder that will be your local working folder.

In windows explorer, right click, SVN checkout.

URL of repository: https://:8443/svn//

Checkout folder: Your local working folder.

Checkout depth: Fully recursive.

Head revision.

OK.


13/25

Client setup / connectivity for SmartSVN SmartSVN client (without jre):

Install with full integration.

Select Foundation version.

In order to connect you need to configure repository profile,

with the following information:

Protocol: https for Internet connection, SVN for network.

Server name: name of server IP.

Repository path: /svn/ for https,

/ for network. Port: non-default 8443.

Corresponding local folder.


14/25

Client setup / connectivity for eclipse Eclipse plugin:

Right click project -> Team -> Share project.

SVN, Next

URL: https://:8443/svn//

Project name as folder name. Finish.

Accept certificate permanently.

Enter username / password.

We import only source & lib usually, we don't include binfolder.


15/25

Basic actions Based on your SVN client, you need to practice the following

basic actions on the 'trunk' folder:

Add / commit.

Update / commit.

Modify / Revert.

Modify several files / commit all with same message.

View revision graph / view log.

Compare between versions / Show differences.

Add folder recursively.

Update local copy to specific revision not just head.

Delete / commit Delete / revert deletion.

You need to get used for the icons on files for your favorite SVN

client, you should find list in the help of the client software.


16/25

Basic actions (cont.) Continue to practice the following tasks:

Lock Modify Unlock to prevent anyone fromchanging in file while you are modifying it.

Export to be used when releasing for taking version.

Try the blame feature to view changes for each line isdone by whom.


17/25

Advanced actions Branching:

Needed when your development team needs to work on twodistinct copies of a project at the same time & keep the two

lines of development distinct, example:

Development of release 2.0

Maintenance of release 1.0

Atomic transactions (Changeset).

Resolving conflict (Best get latest version & apply changesagain).

Reverse Integrate (Merge branch in trunk).

Forward Integrate (Merge trunk in branch).


18/25

Advanced actions (cont.) Tag / Release: Light weight, usually used as naming a release

for a folder and its sub-folders to identify meaningful release(example: Build.1.2.03.prod).


19/25

Best practice Take it slow.

Be precise and exhaustive in your commit comments, try tohave a standard for your company.

Commit your work to the repository as often as you can withoutbreaking the build. Always check-in a compiled version of code

in order not to prevent others from continuing work if updatedtheir working folders. Don't let your working folder become too

valuable.

Keep in touch with the repository i.e. update your working

folder as often as you can without interrupting your own work.It isn't wise to let the distance between your working folder andthe repository grow too large.

If you used merge, merge manually & make sure you have acompiling version before commit.


20/25

Best practice (cont.) Small project: Don't branch or merge.

Don't create a branch unless you are willing to take care of it.

Big projects: Usually have experienced maintainers who keep

track of branches or patches.

Make always your repository root having 3 sub-folders (trunk,

branches, tags).

Don't make branches to keep track of specific customers, betterto build customizability in your application.

Always group your check-in logically (Bug fix, add feature,

particular task).


21/25

VisualSVN Server setup Run installer VisualSVN-Server-x.x.x.msi.

Next, I accept, Next.

Specify location for installer (Require nearly 7 MB).

Specify location for repository (Require large space for your

files). Select authentication type based (Either own subversion users,

or windows users) you may need to consult your system adminbefore decide.

Next, Install. Finish.


22/25

VisualSVN Server setup (cont) What happened after installation:

Service created VisualSVN Server created Automatic startup.

Repository folder contains 5 files now.


23/25

Repository (Server) information Repository = File system x time

Usually the repository store delta between files for each check-in (Either forward or reverse delta or sometime make some

combination).

Backup: dump versus hotcopy.

When you dump, it checks out every single revision in the

repository.

hotcopy is a file copy of your repository database.


24/25

Questions/

Suggestion

ThanksAshraf Fouad


25/25

References

A Visual Guide to Version Control.

Source control how to.

SVN best practice.

5 SVN best practices.

OSCON: Subversion Best Practices.

Version control with subversion.

Documents

Svn Usage Best Practices 090611150004 Phpapp02