Master

PROGRAMMIERPRAKTIKUM
2015
VERSIONSKONTROLLE MIT GIT
Tobias Witt
EINFÜHRUNG
WELCHE PROBLEME KÖNNEN
BEI DER ARBEIT IM TEAM
AUFTRETEN?
ZIELE
•
Protokollierung von Veränderungen
•
Wiederherstellung alter Zustände
•
Koordination gemeinsamer Arbeit
•
Parallele Entwicklungszweige
AUSKOMMENTIEREN
public class MyClass {
private int myInt = 0;
}
public class MyClass {
//private int myInt = 0;
public int myInt = 0;
}
DATEIEN KOPIEREN
MyClass.1.java
MyClass.java
public class MyClass {
private int myInt = 0;
}
public class MyClass {
public int myInt = 0;
}
VERSIONSKONTROLLE
•
Systeme: CVS, SVN, Mercurial, Bazaar
•
Für diese Vorlesung: GIT
$
#
#
#
#
$
git status
On branch master
Changes not staged for commit:
modified: MyClass.java
git diff
public class MyClass {
- private int myInt = 0;
+ public int myInt = 0;
}
$ git commit -m "Make myInt public" MyClass.java
[master a5d0adf] Make myInt public
1 file changed, 1 insertion(+), 1 deletion(-)
BEGRIFFE
Working Copy
Alle Dateien des Projekts in der aktuell gewählten
Version
Staging Area
Änderungen für die nächste Version
Repository
Speicherort für Versionen, Zweige und Markierungen
Remote
Entferntes Repository
Commit
Eine Version. Committen = einen Commit machen
Branch
Entwicklungszweig
Tag
Alias einer Version
ARBEITSABLAUF
1. Synchronisation
2. Arbeit an den Dateien
Lokales
Repository
MyClass.java
MyClass.java
@3cabd97
@3cabd97
3. Commit
MyClass.java
4. Synchronisation
5. Lösen von Kon!ikten
6. Upload der Commits
1
Remote
Repository
4
MyClass.java
@deadbee
@deadbee
MyClass.java
MyClass.java
@acab666
6
@acab666
BEST PRACTICES
•
Commit kein Ersatz für Undo
•
Gemeinsamer Commit zusammengehöriger Änderungen
•
Getrennter Commit verschiedener Änderungen
•
Kein Commit von unsauberem Code
‣
In den Master-Branch
GESCHICHTE
•
2005, Linus Torvalds
•
Linux Kernel
•
Anforderungen:
•
‣
Verteilte Arbeitsabläufe
‣
Sehr hohe Sicherheit gegen Verfälschungen
Heutiger Maintainer: Junio Hamano
ARBEIT MIT GIT
$ git init
Initialized empty Git repository in /MyProject/.git/
Arbeitskopie
Repository
Erstelle .gitignore Datei
$ git status
# On branch master
#
# Initial commit
#
# Untracked files:
#
(use "git add <file>..." to include in what will be committed)
#
#
.gitignore
nothing added to commit but untracked files present (use "git add" to track)
Füge .gitignore Datei zur Staging Area hinzu
und committe
$ git add .gitignore
$ git status
# On branch master
#
# Initial commit
#
# Changes to be committed:
#
(use "git rm --cached <file>..." to unstage)
#
#
new file:
.gitignore
#
$ git commit -m "Initial Commit"
[master (root-commit) 4e3fa80] Initial commit
1 file changed, 1 insertion(+)
create mode 100644 .gitignore
OBJEKTE
Initial Commit
5eaaede
Tree
82e3a75
Commit
Tree (Wurzelbaum)
Blob
.gitignore
9de29bb
BLOBS
•
Referenzieren Dateiinhalte
•
SHA1-Hash aus Dateiinhalt
•
Wiederverwendung
•
Mindestens ein Blob pro Commit
‣
keine leeren Verzeichnisse
$ git show 9de29bb
*.swp
TREES
•
•
•
Referenzieren Verzeichnisse
SHA1-Hash aus enthaltenen Blobs und
Trees
Tree + Blob = Dateireferenz
$ git show 82e3a75
tree 82e3a75
.gitignore
COMMITS
•
Referenzieren Versionen
•
SHA1-Hash aus Autor, Zeitpunkt, Trees, Blobs und
Elterncommit
•
Commit-Bezeichner grundsätzlich eindeutig
COMMITS
$ git show 5eaaede
commit 5eaaede...
Author: Tobias Witt <[email protected]>
Date:
Sun Mar 30 22:48:01 2014 +0200
Initial commit
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1377554
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+*.swp
src
Tree
cccb338
Add src dir
Tree
8badf00d
fdacab6
.gitignore
"bin/"
b00b1e5
Add MyClass
Tree
b16b00b
fadbeef
MyClass.java
"public cl..."
80ff1ce
Initial Commit
Tree
4e3fa80
9b27344
.gitignore
"*.swp"
1377554
MyClass.java
.gitignore
ZUSTÄNDE VON DATEIEN
Untracked
Unmodified
Modified
Staged
Datei hinzufügen (git add)
Datei committen (git commit)
Datei bearbeiten
Datei hinzufügen (git add)
Datei entfernen (git rm)
DER GRAPH
public class MyClass { MyClass.java@a5d0adf
public int myInt = 0;
}
Make myInt
public
a5d0adf
$ git checkout 874d218
HEAD is now at 874d218… Add file
Detached Head
public class MyClass { MyClass.java@874d218
private int myInt = 0;
}
Add MyClass
874d218
HEAD
public class MyClass {
public int myInt = 0;
}
Make myInt
public
a5d0adf
$ git reset --hard 874d218
HEAD is now at 874d218... Add file
public class MyClass {
private int myInt = 0;
}
Add MyClass
874d218
Master
HEAD
BRANCHES
•
Referenz auf Commits
‣
•
Alle Vorgänger Teil vom Branch
Hierarchie: Repository/Branch-Name
‣
remote/master
und master verschiedene Branches
public class MyClass {
public int myInt = 0;
}
Make myInt
public
a5d0adf
$ git branch Menu
$ git checkout Menu
Switched to branch 'Menu'
$ git reset --hard HEAD~1
HEAD is now at 874d218 Add MyClass
public class MyClass {
private int myInt = 0;
}
Add MyClass
874d218
Master
Menu
HEAD
DumbIdea
Bug#91v2
D3
C3
HEAD
D2
Bug#91
B3
C2
C1
Master
D1
M3
B2
$ git merge DumbIdea
M2
B1
M1
Master
DumbIdea
D3
Bug#91v2
D2
C3
Bug#91
$ git merge DumbIdea
$ git branch -D Bug#91
D1
B3
C2
M3
B2
C1
M2
B1
M1
HEAD
DumbIdea
$ git merge DumbIdea
$ git branch -D Bug#91
$ git merge Bug#91v2
Master
Bug#91v2
D3
C3
D2
C2
D1
C1
M3
B2
M2
B1
M1
Master
M4
Merge-Commit
DumbIdea
$
$
$
$
git
git
git
git
merge DumbIdea
branch -D Bug#91
merge Bug#91v2
tag v1.2
v1.2
D3
C3
D2
C2
D1
C1
M3
B2
M2
B1
M1
Bug#91v2
Gian
Tobi
D
D
D
M
M
M
M
Max
C
C
C
B
B
Origin
Pakan
PUSH
•
Upload der Commits
•
Kein Zusammenführen von master und origin/master
$ git push origin master
Remotename
Branchname
FETCH, MERGE & PULL
•
Fetch Synchronisation mit Remote Repository
$ git fetch origin master
Remotename
Branchname
•
Merge Zusammenführen von Remote Branches
$ git merge origin/master
•
Konfliktpotential
Pull Fetch gefolgt von Merge
$ git pull origin master
Rücksichtsloser Merge
PLÄTZE FÜR DATEIEN
Working
Copy
Staging
Area
Local
Repository
Remote
Repository
Datei hinzufügen (git add)
Datei committen (git commit)
Commits pushen (git push)
Commits fetchen (git fetch)
Commits zusammenführen (git merge)
Commits pullen (git pull)
MERGE VS. REBASE
Eventuell
unerwünscht
HEAD
HEAD
Bug
Master
Bug
Master
Master
Bug
Master
Bug
$ git merge Bug
$ git rebase master
BEISPIEL
PROJEKT
.gitignore
# IntelliJ
.idea/
*.iml
*.iws
out/
doc/
# Java
*.class
hs_err_pid*
Main.java
package de.hhu.propra14.team66;
public class Main {
public static void main(String[] args) {
}
}
$ git config --global user.name "Tobias Witt"
Tobi
$ git config --global user.email [email protected]
IntelliJ-Projekt
$ git init
Initialized empty Git repository in /Users/tobi/Team66/.git/
$ git status
# On branch master
#
# Initial commit
#
# Untracked files:
#
(use "git add <file>..." to include in what will be committed)
#
#
.gitignore
#
src/
nothing added to commit but untracked files present (use "git add" to track)
Tobi
$ git add .
Tobi
$ git commit -m "Initial Commit"
[master (root-commit) b966b35] Initial Commit
2 file changed, 15 insertions(+)
create mode 100644 .gitignore
$ git remote add origin [email protected]:ProPra14/team66.git
$ git push -u origin master
Counting objects: 4, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (4/4), 558 bytes, done.
Total 4 (delta 0), reused 0 (delta 0)
Neuer Remote Branch
To [email protected]:ProPra14/team66.git
* [new branch]
master -> master
Branch master set up to track remote branch master from origin.
Tobi
Origin
master
origin/master
1
1
$ git config --global user.name "Arsham Sabbaghi Asl" Pakan
$ git config --global user.email [email protected]
$ git clone [email protected]:ProPra14/team66.git
Cloning into 'team66'...
remote: Counting objects: 4, done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 5 (delta 0), reused 0 (delta 0)
Receiving objects: 100% (4/4), done.
$ git add src/de/hhu/propra14/team66/Game.java
$ git commit -m "Add Game class"
[master b9ec7c1] Add Game class
1 file changed, 15 insertions(+)
create mode 100644 src/de/hhu/propra14/team66/Game.java
$ git push
...
To [email protected]:ProPra14/team66.git
b966b35..b9ec7c1 master -> master
Tobi
master
1
Origin
Pakan
origin/master
master
2
2
1
1
Nicht im
Klon klonen !
$ git pull
Updating b966b35..b9ec7c1
Fast-forward
src/Game.java |
15 +++++++++++++++
1 file changed, 15 insertions(+)
create mode 100644 src/Game.java
Tobi
Tobi
Origin
Pakan
master
origin/master
master
2
2
2
1
1
1
$ git diff
...
for
+
int
+
for
+
+
+
}
...
Tobi
(int i = 0; i < rolls.length; i++)
score += rolls[i];
score = 0, roll = 0;
(int frame = 0; frame < rolls.length/2; frame++) {
score += rolls[roll] + rolls[roll+1];
roll += 2;
Konflikt
Pakan
$ git diff
...
for (int i = 0; i < rolls.length; i++)
score += rolls[i];
+
int score = 0, roll = 0;
+
for (int frame = 0; frame < rolls.length/2; frame++) {
+
score += scoreIn(roll);
+
roll += 2;
...
+
+
private int scoreIn(int roll) {
+
return rolls[roll] + rolls[roll+1];
+
}
}
Pakan
$ git commit -am "Make Game spare ready"
[master 47294f3] Make Game spare ready
1 file changed, 9 insertions(+), 3 deletions(-)
$ git push
Counting objects: 7, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (3/3), done.
Writing objects: 100% (4/4), 512 bytes, done.
Total 4 (delta 1), reused 0 (delta 0)
To [email protected]:ProPra14/team66.git
b9ec7c1..47294f3 master -> master
Impliziert
git add .
Tobi
Origin
Pakan
Sicher
(relativ)
origin/master
master
3
3
2
2
2
1
1
1
master
Tobi
$ git commit -am "Game is now spare ready"
[master 4abd3b5] Game is now spare ready
1 file changed, 5 insertions(+), 3 deletions(-)
$ git push
To [email protected]:ProPra14/team66.git
! [rejected]
master -> master (non-fast-forward)
error: failed to push some refs to '[email protected]:ProPra14/team66.git'
hint: Updates were rejected because the tip of your current branch
hint: is behind its remote counterpart. Merge the remote changes
hint: (e.g. 'git pull') before pushing again. See the 'Note about
hint: fast-forwards' in 'git push --help' for details.
Tobi
$ git commit -am "Game is now spare ready"
[master 4abd3b5] Game is now spare ready
1 file changed, 5 insertions(+), 3 deletions(-)
$ git push
To [email protected]:ProPra14/team66.git
! [rejected]
master -> master (non-fast-forward)
error: failed to push some refs to '[email protected]:ProPra14/team66.git'
Schlechter hint: Updates were rejected because the tip of your current branch
Vorschlag hint: is behind its remote counterpart. Merge the remote changes
hint: (e.g. 'git pull') before pushing again. See the 'Note about
hint: fast-forwards' in 'git push --help' for details.
$ git pull
...
From github.com:ProPra14/team66
b9ec7c1..47294f3 master
-> origin/master
Auto-merging src/Game.java
CONFLICT (content): Merge conflict in src/Game.java
Automatic merge failed; fix conflicts and then commit the result.
$ git status
# On branch master
# Your branch and 'origin/master' have diverged,
# and have 1 and 1 different commit each, respectively.
#
# Unmerged paths:
#
(use "git add/rm <file>..." as appropriate to mark resolution)
#
#
both modified:
src/Game.java
#
no changes added to commit (use "git add" and/or "git commit -a")
src/Game.java
public class Game {
//...
public int score() {
int score = 0, i = 0;
Lokal
for (int frame = 0; frame < rolls.length/2; frame++) {
<<<<<<< HEAD
score += rolls[i] + rolls[i+1];
=======
score += scoreIn(i);
>>>>>>> 5b3dd08272b5db72db9c850035a589cf61de170e
i += 2;
Remote
}
return score;
}
//...
}
//...
int score = 0, i = 0;
for (int frame = 0; frame < rolls.length/2; frame++) {
score += scoreIn(i);
i += 2;
}
//...
$ git commit -am "Merge origin/master"
Tobi
[master 4f25a92] Merge origin/master
$ git push
Counting objects: 11, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (5/5), 534 bytes, done.
Total 5 (delta 2), reused 0 (delta 0)
To [email protected]:ProPra14/team66.git
5b3dd08..4f25a92 master -> master
Pakan
$ git pull
Tobi
master
Origin
Pakan
origin/master
master
4
4
4
3'
2
3
3
3'
2
3
3'
2
origin/master
1
1
1
PROJEKT
https://git.hhu.de/programmierpraktikum-2015/team<nr>
[email protected]:programmierpraktikum-2015/team<nr>.git
$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/tobi/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Private Key
Enter same passphrase again:
Your identification has been saved in /Users/tobi/.ssh/id_rsa.
Your public key has been saved in /Users/tobi/.ssh/id_rsa.pub.
The key fingerprint is:
Public Key
ce:57:85:83:13:a8:d4:0c:44:a1:e6:ca:e3:41:be:5c [email protected]
The key's randomart image is:
+--[ RSA 2048]----+
|
o== ..
|
|
.. + o .
|
|
o. . o o . |
|
o .
. o
|
| . .
S
.
|
| + .
o
.
|
| * E
o .
|
| o =
.
|
| +
|
+-----------------+
Public(!) Key
•
Git-Commits = Leistungsnachweis
•
Regelmäßig Committen
•
Sinnvolle Commit-Kommentare
•
Weitere Informationen in den Übungen
HILFSQUELLEN
•
•
•
GIT-Homepage
‣
http://git-scm.com
‣
http://git-scm.com/book
GIT-Cheat-Sheets
‣
https://raw.github.com/AlexZeitler/gitcheatsheet/master/gitcheatsheet.pdf
‣
http://www.ndpsoftware.com/git-cheatsheet.html
‣
http://byte.kde.org/~zrusin/git/git-cheat-sheet-medium.png
Git for ages 4 and up
‣
https://www.youtube.com/watch?v=1#BJ4sVUb4
BILDQUELLEN
Bild
Quelle
Memes
http://quickmeme.com, http://imgflip.com/memegenerator,
http://alltheragefaces.com
Github-Comic
http://www.flickr.com/photos/dullhunk/6251011880
Robot that Screams
http://www.hornoxe.com/wp-content/picdumps/
picdump305/hornoxe.com_picdump305_016.jpg