Deel III: Paradigma’s Software Ontwikkeling 1. Concurrent Versions System (CVS)

Vakgroep Informatietechnologie

Deel III: Paradigma’s Software Ontwikkeling

1. Concurrent Versions System (CVS)

Prof.Dr.Ir. Filip De Turck

Software Ontwikkeling I

Structuur Deel III

Concurrent Versions System (CVS) Make-bestanden versus Ant Recente talen en gedistribueerde

applicaties: Ruby Web services

Ontwerp van Telecom-diensten Video-conferentie applicaties Software voor mobiele toestellen Andere voorbeelden


Outline

CVS - Concurrent Versions System What’s CVS Proper usage Tagging, branching, merging Sample File Header CVS implementation and alternatives


CVS - What’s CVS

CVS … … is a server system, that stores files in a general

place … allows several people to access these files, and

elaborate them at the same time … keeps “track changes” you’ve made to the file … allows to see the differences through time

CVS often is misused … … as a simple backup system … without a proper structure


CVS - What’s CVS - checkout

The server contains the data All data are called “the repository”

You get the files by checking out a copy from the server to your local PC

Everybody can access the data If you don’t care, everybody can

access You can create a list of “only-allowed”

CVS Server

Another desktopYour desktop

checkout

Operating Systems: Linux, Windows, FreeBSD, Mac OS X

License: GNU General Public License


CVS - What’s CVS - modules

When checking out, you get a “module” A module is a grouping of data A module contains files, directories, …


CVS - What’s CVS – commit

Checkout and commit After checking out a module, you can locally edit

your files After editing, your local copy differs

from the one on the server You synchronize your local copy

with the server by committing your changes

CVS Server

Your desktop

commit

Local

edit


CVS - What’s CVS – diff

Only a diff is stored When committing a new file, the old file is not

simply overwritten. A diff is made with the previous file, and this is

stored. Your file gets a new version number,

a log message is attached. The log contains a brief description

of the changes you’ve made Yes, you have to do this yourself

CVS Server

1.2

1.1

Foo.c

Log Msg


CVS - What’s CVS – diff (2)

Since a diff is stored… the server contains all versions you can browse through the history and changes


CVS - What’s CVS – first checkout

After a commit Your PC contains the latest version The repository contains all version,

including the last Another user still has the previous

version He needs to update before he starts

working

Always first checkout / update before you start working on a module

Another desktopYour desktop

CVS Server

update


Several people can work at the same time on different files:

I’m working on file A You’re working on file B We both commit Every one checks out again,

and has the most recent versions– Always update first!

on the same file: When both working on a

different section, it’s merged When there’s a conflict

it’s reported

commit commitupdateupdate

CVS - What’s CVS – different people

Your desktop

CVS Server

Another desktop


CVS - Proper usage – do’s

Do’s Working on an existing module:

Check out before working on files Commit after you’ve finished Add a comment, indicating your changes

Creating a new module / new file: Plan your directory structure:

– setup notes don’t belong in between software– a separate directory for figures might be handy

Think of a proper name– E.g. practicum.tex doesn’t say a lot

A new module is normally only committed, once a “stable version” is created


CVS - Proper usage – don’ts

Don’ts Don’t commit changes without a Message Log.

Even “typo fixed” is valid

CVS is designed for text based files, not for binaries:

Don’t commit the compiled versions of source code Don’t commit the pdf’d version of a tex file Don’t commit every tiny change of a jpeg file

Don’t put everything in one directory, and afterwards try to sort it out:

Moving a file or a directory isn’t possible Removing files actually doesn’t happen


CVS - Proper usage – don’ts in practice

Geen log message !


CVS - Proper usage – don’ts in practice

Geen structuur !


Outline

CVS - Concurrent Versions System What’s CVS Proper usage Tagging, branching, merging Sample File Header CVS implementations and alternatives


CVS - Tagging

After working for a while… Some files needed a lot of changes, others didn’t Each file has different revisions, e.g. 5

+-----+ +-----+ +-----+ +-----+ +-----+! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !+-----+ +-----+ +-----+ +-----+ +-----+

At a certain moment, you can put a tag on your current version

E.g. rel-1-1 E.g. version2006

The revision numbers don’t change, you add an extra label as a human understandable reference


file1 file2 file3 file4 file5

1.1 1.2 1.1 1.3 _1.1 1.2 1.4 1.1 /1.2*----1.3*----1.5*----1.2*----1.1* (--- <--- Look here1.3 1.6 1.3 \_1.4 1.4 1.5

CVS - Tagging

A bunch of files for example After tagging, some files are further developed You can now easily get back to the different

revisions of that moment by “pulling the tag”

file1 file2 file3 file4 file5

1.1 1.1 1.1 1.1 /--1.1* <-*- TAG1.2*- 1.2 1.2 -1.2*-1.3 \- 1.3*- 1.3 / 1.31.4 \ 1.4 / 1.4 \-1.5*- 1.5 1.6


CVS - Branching

Usage You have a huge bug since v1.2, and you need to fix it to

release a patch to people using v1.2 You want to try something out based on 1.2, but leave

version 1.5 alone +-------------+ Branch 1.2.2.3.2 -> ! 1.2.2.3.2.1 ! / +-------------+ / / +---------+ +---------+ +---------+Branch 1.2.2 -> _! 1.2.2.1 !----! 1.2.2.2 !----! 1.2.2.3 ! / +---------+ +---------+ +---------+ / /+-----+ +-----+ +-----+ +-----+ +-----+! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 ! <- The main trunk+-----+ +-----+ +-----+ +-----+ +-----+ ! ! ! +---------+ +---------+ +---------+Branch 1.2.4 -> +---! 1.2.4.1 !----! 1.2.4.2 !----! 1.2.4.3 ! +---------+ +---------+ +---------+


CVS - Merging

Usage You have a huge bug since v1.2, and you need to fix it to

release a patch to people using v1.2 The bug is still in v1.4, and you want to apply the same

changes– Go back to the trunk– Join the changes of v1.2.2.2 into a new v1.5

+-----+ +-----+ +-----+ +-----+ +-----+! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 ! <- The main trunk+-----+ +-----+ +-----+ +-----+ +-----+ ! * ! * ! +---------+ +---------+Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 ! +---------+ +---------+


Outline



CVS - Sample File Header

/**************************************************

Filename: $Id$

Author: $Author$

Last Changed: $Date$

Log: $Log$

***************************************************/

…

(further contents of file)

…


CVS - Keywords in file header

$Author$ The user name

$Date$ The date and time of the revision was checked in.

$Header$ A standard header containing the full pathname of the file,

the revision number, the date, the author $Id$

Same as Header: but file name doesn't have path. $Name$

Tag name used to check out this file. $Log$

Stores log message. $Revision$

The revision number assigned to the revision


Outline



CVS - Implementations

Tortoise CVS: a shell-integrated CVS client for Windows

Subversion: an open-source revision control system

DCVS: a distributed revision control system based on

CVS Bonsai CVS code management system:

a tool to reports on files, directories, and branches under CVS management.

Commercial: IBM Rational Clear case, etc.

Vakgroep Informatietechnologie

Deel III: Paradigma’s Software Ontwikkeling

2. Make-bestanden versus Ant

Prof.Dr.Ir. Filip De Turck


Make files

to automate the build process

cfr overview in Minerva folder Extra_Notes/unix_makefiles.pdf

Java alternative: Anthttp://supportweb.cs.bham.ac.uk/docs/tutorials/docsystem/build/tutorials/ant/ant.pdf

(ook beschikbaar op Minerva : Extra_Notes/ant.pdf)


Maven

Maven is a software tool for Java programming language project management and automated software build.

Similar in functionality to the Apache Ant tool but has a simpler build configuration model, based on an XML format.

Maven is hosted by the Apache Software Foundation, where it was formerly part of the Jakarta Project.

Maven uses a construct known as a Project Object Model (POM) to describe the software project being built, its dependencies on other external modules and components, and the build order.

It comes with pre-defined targets for performing certain well defined tasks such as compilation of code and its packaging.

Support for download plugins on network repositories and upload completed builds

http://maven.apache.org/

Deel III: Paradigma’s Software Ontwikkeling 1. Concurrent Versions System (CVS)

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