1. Subversion

2. Subversion: What To Do? Problems of code management in a project
The life of the project can be lengthy: need to manage the development history
Change of architecture
Change of people involved in the development
Working in parallel on several versions
Maintenance of an old version in parallel with the current version
Test of new functionality without an impact to the current version
Being able to easily spread change from one version to another
Several people involved at the same time in development
Working simultaneously on the same code
Detect and help to resolve conflicts
Family member of Version Control System (VCS)
CVS is 1 of the oldest and best known (open source)
Subversion (SVN) covers the main concepts while modernising
Text and binary, language neutral, not configuration management

3. The model CVS/SVN repository Working area Working area A B
check-out
check-out
Local copies in working area
No "locking": several users may modify different copies
of the same file
Central repository
Database containing all versions (revisions)
unique to a single project
commit
(check-in)
Working area B
Working area A
Synchronisation between the working area and the repository
Detection/Resolution of conflicts

4. SVN: Reference a Repository
We specify a repository by its URL
Example: https: / / svn.lal.in2p3.fr/projects/Etudiants
We call a branch any directory in the repository
Matches a directory in the workspace
An additional level in the URL
Examples:
https: / / svn.lal.in2p3.fr/projects/Etudiants/ipn5
https: / / svn.lal.in2p3.fr/projects/Etudiants/ipn5/HelloWorld
Wide range of SVN customers
Command line: svn
Command names generally identical to CVS
Web Client: WebSVN
Only views the repository

5. Major Operations checkout update revert info status resolved log addWA R WA WA R
checkout
update
revert
info
status
resolved
log
add
commit

6. Check-out Creates a local copy (a branch) repository svn co URL
Ex : svn co Projects R WA
% svn co Projects
Checked out revision 4.
% cd Projets/

7. Info Lets you know the branch associated with the local directory
svn info WA
% svn info
Path: .
URL:
Repository UUID: 589c a-0410-a932-a3fdf8820ca6
Revision: 4
Node Kind: directory
Schedule: normal
Last Changed Author: jouvin
Last Changed Rev: 4
Last Changed Date: :07: (Tue, 17 Jan 2006)

8. Add Adds file(s) to the repository at the next synchronization
svn add file / directory
Necessary for any file/directory created after the check-out
If directory is selected, treats all contained files and directories R WA
% echo "Test" > file1.txt
% svn add file1.txt
A file1.txt

9. Status Lets you know the status of the working directory
svn status [-u]
1 line per file modified with respect to the repository
-u forces verification compared to the repository and not the local copy WA
% svn status
A file1.txt

10. Commit Writes local changes to the repository svn ci -m "message"
Creates a new revision of the repository containing all the changes
Requests a username/password if necessary (ens2006, non-modifiable)
Possible only if the workspace is up to date as compared to the repository R WA
% svn ci -m 'Ajout de file1.txt'
Adding file1.txt
Authentication realm: < LAL …
Password for 'jouvin':
Transmitting file data .
Committed revision 5.

11. Update Imports changes from the repository to the local copy
svn update [-r revision]
Adds new files (A) or updates others (U)
Preserves local changes by doing a merge (G)
Indicates conflict: local modification in conflict with a change in the repository (C)
In case of conflict, creates several versions of file locally
Prevents commits R WA
% echo “Personal change” >> file1.txt
% svn update
C file1.txt  conflit in the file
A file2.txt  added file
Updated to revision 7.
% ls
file1.txt file1.txt.r5 file2.txt
file1.txt.mine file1.txt.r7

12. Resolved Indicates that the conflict was resolved svn resolved file
Deletes versions created temporarily WA
% cp file1.txt.mine file1.txt
% svn resolved file1.txt
file1.txt file1.txt.mine file1.txt.r5 file1.txt.r7
Resolved conflicted state of 'file1.txt'
% ls
file1.txt file2.txt

13. Revert Returns to the version of the repository
svn revert file/directory
Restores version of the last update. The local changes are lost R WA
% cat file1.txt
Test
Modif perso
% svn revert file1.txt
Reverted 'file1.txt'
1st modif

14. Log Lists messages associated with each revision of a file/directory
svn log [file/directory] [-v] [--stop-on-copy]
Lists only revisions applied to the current branch (file)
Includes copy operations between branches, unless --stop-on-copy R
asc/jouvin % svn log
r7 | jouvin | :53: (Wed, 18 Jan 2006) | 1 line
Modif 1st file
r6 | jouvin | :51: (Wed, 18 Jan 2006) | 1 line
Add 2nd file
r5 | jouvin | :49: (Tue, 17 Jan 2006) | 1 line
Add file1.txt ……

15. Summary of Major Operations ...
check-out : creates a local copy (a branch) repository
svn co URL
Ex : svn co Projects
info : lets you know the branch associated with the local directory
svn info
add : adds file(s) to the repository at the next synchronization
svn add file / directory
Necessary for any file/directory created after the check-out
If directory is selected, treats all contained files and directories
status : lets you know the status of the working directory
svn status [-u]
1 line per file modified with respect to the repository
-u forces verification compared to the repository and not the local copy R WA WA R WA WA

16. ... Summary of Major Operations…
commit : writes local changes in the repository
svn ci -m "message"
Creates a new revision of the repository containing all the changes
Requests a username/password if necessary (ens2006, non-modifiable)
Possible only if the workspace is up to date as compared to the repository
update : imports changes from the repository in the local copy
svn update [-r revision]
Adds new files (A) or updates others (U)
Preserves local changes by doing a merge (G)
Indicates conflict: local modification in conflict with a change in the repository (C)
In case of conflict, creates several versions of file locally
Prevents commits
resolved : indicates that the conflict was resolved
svn resolved file
Deletes versions created temporarily R WA R WA WA

17. … Summary of Major Operations
revert : returns to the version of the repository
svn revert file/directory
Restores version of the last update. The local changes are lost
log : lists messages associated with each revision of a file/directory
svn log [file/directory] [-v] [--stop-on-copy]
Lists only revisions applied to the current branch (file)
Includes copy operations between branches, unless --stop-on-copy R WA R

18. Operations on Files ...
SVN keeps a track of all files renamed, copied, destroyed…
Helps to maintain the history even if the file is renamed
Reports the revision of the file which resulted in a new file (copy /mv)
Manages the creation/deletion/rename of directories
No implicit transactions on files
Must notify the changes to SVN
svn status indicates inconsistencies (!)
To simplify, SVN allows to invoke the cp, mv, mkdir…
svn cp, mv svn, svn rm, svn mkdir
Make SVN forget about a deleted file
svn rm --force file

19. ... Operations on Files % svn cp file1.txt file3.txt A file3.txt % ls
file1.txt file2.txt file3.txt
% svn status
A + file3.txt

20. Advanced Features
diff: shows the differences between 2 versions of a file or group of files
With the work space: svn diff [-r revision] file/directory
Between 2 revisions to the repository: svn diff [-r r1:r2] file/directory
Easier with a Web interface (WebSVN, Trac…)
WebSVN the LAL:
merge: reverts to an earlier revision of the repository
svn merge -r HEAD:revision file/directory
Does not change the repository but only the local copy (you have to commit to validate a return to the previous revision)
update helps to restore an earlier version in the work area but will cause a conflict when committed
commit requires that the workspace is up to date with the last revision R WA

21. To Learn More… Documentation SVN online
The online help
svn help [command]