Git in industry companies and projects currently

GIT IN INDUSTRY
Companies and projects currently using Git
• Google
• Android
• Facebook
• Microsoft
• Netflix
• Linux
• Ruby on Rails
• Gnome
• KDE
• Eclipse
• X.org
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GIT BASICS
Snapshots , not changes
• A picture of what all your files look like at that moment
• If a file has not changed, store a reference
Nearly every operation is local
• Browsing the history of project
• See changes between two versions
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WHY GIT IS BETTER
Git tracks the content rather than the files
Branches are lightweight, and merging is a simple process
Allows for a more streamlined offline development process
Repositories are smaller in size and are stored in a single .git
directory
Allows for advanced staging operations, and the use of
stashing when working through troublesome sections
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WHAT ABOUT SVN?
Linus Torvalds
Subversion has been the most pointless project ever started …
Subversion used to say CVS done right: with that slogan there is
nowhere you can go. There is no way to do CVS right … If you like
using CVS, you should be in some kind of mental institution or
somewhere else.
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GIT VS {CVS, SVN, …}
Why you should care:
• Many places use legacy systems that will cause problems in
the future – be the change you believe in!
Git is much faster than SVN:
• Coded in C, which allows for a great amount of optimization
• Accomplishes much of the logic client side, thereby reducing
time needed for communication
• Developed to work on the Linux kernel, so that large project
manipulation is at the forefront of the benchmarks
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GIT VS {CVS, SVN, …}
Speed benchmarks:
Benchmarks performed by
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GIT VS {CVS, SVN, …}
Git is significantly smaller than SVN
• All files are contained in a small decentralized .git file
• In the case of Mozilla’s projects, a Git repository was 30 times
smaller than an identical SVN repository
• Entire Linux kernel with 5 years of versioning contained in a
single 1 GB .git file
• SVN carries two complete copies of each file, while Git
maintains a simple and separate 100 bytes of data per file,
noting changes and supporting operations
Nice because you can (and do!) store the whole thing locally
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GIT VS {CVS, SVN, …}
Git is more secure than SVN
• All commits are uniquely hashed for both security and indexing
purposes
• Commits can be authenticated through numerous means
• In the case of SSH commits, a key may be provided by both
the client and server to guarantee authenticity and prevent
against unauthorized access
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GIT VS {CVS, SVN, …}
Git is decentralized :
• Each user contains an individual repository and can check
commits against itself, allowing for detailed local revisioning
• Being decentralized allows for easy replication and deployment
• In this case, SVN relies on a single centralized repository and
is unusable without
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GIT VS {CVS, SVN, …}
Git is flexible :
• Due to it’s decentralized nature, git commits can be stored
locally, or committed through HTTP, SSH, FTP, or even by Email
• No need for a centralized repository
• Developed as a command line utility, which allows a large
amount of features to be built and customized on top of it
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