Distributed version control with git a brief...
77
Andrei Chis Distributed version control with git — a brief introduction based on slides by Oscar Nierstrasz
Transcript of Distributed version control with git a brief...
Andrei Chis
Distributed version control with git — a brief introduction
based on slides by Oscar Nierstrasz
Why version control?
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Bob
Why version control?
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Bob Carol
Why version control?
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Bob Carol
TedAlice
Why version control?
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Bob Carol
TedAlice
Why version control?
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Bob Carol
TedAlice
Why version control?
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Bob Carol
TedAlice
A recipe for disaster!
Why version control?
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Cope with the confusion that happens when multiple people edit
the same files
Why version control?
Bob
Repository
Carol
Bob
Repository
Carol
Bob
Repository
Snapshot Version 1
Carol
Bob
Repository
Version 1
Carol
Bob
Repository
Snapshot
Version 1
Version 2Carol
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Repository
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CarolVersion 2
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Repository
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CarolVersion 2
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CarolVersion 2
SnapshotVersion 3
Bob
Repository
Version 1
CarolVersion 2
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AliceTed
Bob
Repository
Version 1
CarolVersion 2
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AliceTed
Can still lead to disaster!
Controlled evolution
git
gitTracks the history of a collection of files
gitTracks the history of a collection of files
Can revert the collection of files to another version
git
distributed version control
system
What is acentralized version
control system?
Bob Carol
Central repository
Bob Carol
Central repository
checkout
Bob Carol
Central repository
checkoutcheckout
Bob Carol
Central repository
Bob Carol
Central repository
commit
Bob Carol
Central repository
updatecommit
Bob Carol
Central repository
commit
Bob Carol
Central repository
commit
Bob Carol
Central repository
commit commitconflict
X
Bob Carol
Central repository
commit commitconflict
X
you must update before every commit
What is adistributed version
control system?
Bob Carol
Remote repository(groupXY)
Bob Carol
Remote repository(groupXY)
local repository
clone
Bob Carol
Remote repository(groupXY)
local repository
clone
local repository
clone
Bob Carol
Remote repository(groupXY)
local repository
local repository
Bob Carol
Remote repository(groupXY)
local repository
local repositorycommit
Bob Carol
Remote repository(groupXY)
local repository
local repositorycommit
push
Bob Carol
Remote repository(groupXY)
local repository
local repositorycommit
push pull
Bob Carol
Remote repository(groupXY)
local repository
local repositorycommit
push
Bob Carol
Remote repository(groupXY)
local repository
local repositorycommit
push
Bob Carol
Remote repository(groupXY)
local repository
local repositorycommit
pushcommit
Bob Carol
Remote repository(groupXY)
local repository
local repositorycommit
pushcommitpush
conflict
X
Bob Carol
Remote repository(groupXY)
local repository
local repositorycommit
pushcommitpush
conflict
X
you must pull before every push
groupX
groupX
Remote repository
(p2exercises)
groupX
Remote repository
(p2exercises)
groupX
git remote add p2exercises ...
Remote repository
(p2exercises)
groupX
git remote add p2exercises ...
git pull p2exercises master
Remote repository
(p2exercises)
groupX
Remote repository
(p2exercises)
groupX
do not commit after the deadline; it leads to merge conflicts
Remote repository
(p2exercises)
Basic git
commit
A “commit” is “a set of changes” to a “set of files”
commitcommit
Most commits modify (or merge) earlier commits
commit
branch
commit
A graph of commits may belong to a
branch
commit
master
commit
master is the main branch
commit
HEAD
master
commit
“HEAD “is the current branch
mkdir repocd repogit init
Create a git repo
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HEAD
master
git add …
Tell git to “stage” changes
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HEAD
master
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HEAD
master
git commit …
Commit your changes
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Collaborating
Public repoLocal repo
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Local repo
master
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Public repoLocal repo
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Local repo
git clone …
git clone …
mastermastermaster
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Public repoLocal repo
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Local repo
git add …git commit …
git add …git commit …
mastermastermaster
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Public repoLocal repo
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Local repo
git pull
(nothing new to pull)
mastermastermaster
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Public repoLocal repo
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git push
mastermastermaster
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git pull
master
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Public repoLocal repo
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git pull
NB: git pull = fetch + merge
master
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mastermaster
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git push
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git pull
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master
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to be continued
Resources
http://book.git-scm.com/index.htmlhttp://git-scm.com/
https://github.com/
http://www.slideshare.net/chacon/getting-git http://oreilly.com/
http://creativecommons.org/licenses/by-sa/3.0/
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