ClearCase

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ClearCase

• Software version control system

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Having a Software configuration Management Tool
is very importantin the field of software
development
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I will Talk about,

• Source Control in general
• List of existing Source Version Control Software
• Version Control with ClearCase
• Summary

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Source Control
Lubas workspace

• main line

0
check out
versions
a_file.c
check in
1
2
3
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List of existing Source Version Control
Software There are a lot of them
!http//www.iac.honeywell.com/Pub/Tech/CM/CMToo
ls.htmlCMWWWsites

• ClearCase - Windows and UNIX
• Visual SourceSafe - Windows
• CVS - UNIX
• CMVision - Unix and Windows
• Control CS - Unix and Windows
• the list goes on

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What is ClearCase?

• ClearCase is a comprehensive
• software version control and
• configuration management system,
• designed for development teams
• working in a local network.

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ClearCase Overview

• Provides versioning of all types of files
  directories
• Records and reports history
• Guarantees accurate reproduction of every release
• Provides traceability reproducibility
• Provides powerful branch-and-merge tools
• Assures integrity of all software elements

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Version Control with ClearCase

• Branching
• Merging
• Labeling

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Version Control with ClearCase

• \main

- Versions all file types - Versions
directories - Files are read-only until
checked out - Unlimited branching and merging
0
VERSIONS
Beta_01
1
BRANCH
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LABELS
Rls1.0
\Rls2_bugfix
Rls2.0
3
0
1
4
2
Rls3.0
5
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ClearCase Version Control Features

• Easy checkout-edit-checkin model
• Intelligent merge utility automatically merges
  non-conflicting changes
• Graphical compare and merge tools
• Two modes of work with Dynamic and Snapshot Views

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Workspace Management - Views

• WHAT IS A VIEW?
• Workspace for an individual developer or closely
  coordinated group
• Selects versions of Versioned Object Base (VOB)
  directories and files
• Allows developers to work without interfering
  with others

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What is a VOB? Versioned Object Base

• A read-only repository of ClearCase elements
• A network-wide, file system resource which stores
  version-controlled data
• A user accesible repository that resides
• on a Windows NT system, or
• on a UNIX system

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Version Selection by Views

• A view selects versions of elements
• What is seen is the result of an ordered
• set of rules called a configuration
  specification
• (config spec).
• Selected versions appear in a standard
• directory tree with recognizable file names.
• load \applet\src
• element CHECKEDOUT
• element \main\LATEST

VOB
foo.c src bar.c
config spec
V I E W
src foo.c bar.c
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What is a Configuration Specification?

• Each view has a config spec that defines a set of
  rules for selecting versions of file and
  directory elements
• A default config spec is automatically set
  whenever you create a new view

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• The default config spec selects files or
  directories that are
• checked out, or
• the latest version on the main branch of the
  version tree
• The Default Config Spec
• element CHECKEDOUT
• element \main\LATEST

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Workspace Management - Views

• Dynamic Views
• Snapshot Views

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Snapshot Views

• Downloads files based on Rules
• Allows work while disconnected
• from the net
• Optimal build performance
• for prototype or test builds
• load \applet\src
• element CHECKEDOUT
• element \

VOB
foo.c src bar.c
Snapshot View
src foo.c bar.c
CLIENT
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When To Use Snapshot Views

• You want to work with source files that are under
  ClearCase control while disconnected from network
• You prefer to use a view that is updated only at
  your request
• You want to access a view from a machine that is
  not a ClearCase host

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Dynamic Views

• Transparent access to elements
• - a virtual filesystem
• Always up-to-date
• Minimal copying
• Provides build auditing

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Snapshot View vs. Dynamic View

• Similar
• use config specs rules to select element versions
• follow the checkout, edit, checkin paradigm
• allow reserved or unreserved checkouts

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Snapshot View vs. Dynamic View

• Differ
• as development progress, a snapshot view becomes
  out of date and must be explicitly updated
• a checkout of an element may use the version
  loaded into the view, not necessarily the latest
  version in the VOB
• to check in such an element, you may have to
  perform a merge
• if the element version is not the latest version,
  you are asked to confirm which version to checkout

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20 minutes is NOT enough to cover everything. If
you are interested in learning more about
ClearCase, here is the web site
http//www.rational.com/index.jtmpl
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If asked what the talk was about, these are the
things you must remember, )

• WE DISCUSSED
• checkout-edit-checkin model
• Labeling
• Branching
• Merging
• Views
• Config Spec
• WE HAD A LOT OF FUN!!!