Gitresearchcomputing.github.io/meetup_spring_2015/pdfs/Git.pdf · Git can quickly determine whether...
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Git
Transcript of Gitresearchcomputing.github.io/meetup_spring_2015/pdfs/Git.pdf · Git can quickly determine whether...
Git
Git Reference
http://gitref.org/
Pro Githttp://git-scm.com/book
How to think like Git
this is all Git is
The Git Object Model
The SHA
6ff87c4664981e4397625791c8ea3bbb5f2279a3
The SHA: why it's awesome
● Git can quickly determine whether two objects are identical or not, just by comparing names.
The SHA: why it's awesome
● Git can quickly determine whether two objects are identical or not, just by comparing names.
● Since object names are computed the same way in every repository, the same content stored in two repositories will always be stored under the same name.
The SHA: why it's awesome
● Git can quickly determine whether two objects are identical or not, just by comparing names.
● Since object names are computed the same way in every repository, the same content stored in two repositories will always be stored under the same name.
● For the same reason, different content created in two different repositories will never have conflicting names.
The SHA: why it's awesome
● Git can quickly determine whether two objects are identical or not, just by comparing names.
● Since object names are computed the same way in every repository, the same content stored in two repositories will always be stored under the same name.
● For the same reason, different content created in two different repositories will never have conflicting names.
● Git can detect errors when it reads an object by checking that the object's name is still the SHA1 hash of its contents.
The SHA: why it's awesome
● Git can quickly determine whether two objects are identical or not, just by comparing names.
● Since object names are computed the same way in every repository, the same content stored in two repositories will always be stored under the same name.
● For the same reason, different content created in two different repositories will never have conflicting names.
● Git can detect errors when it reads an object by checking that the object's name is still the SHA1 hash of its contents.
Blobs
● Content only (no filenames)● Single revision (changes are
represented as new blobs)
Trees
● Directory hierarchy and filenames● Single revision (changes are
represented as new trees which might reference existing trees and blobs)
Commits
● Annotated top-level tree● Most prominent object in day-to-
day use
Tags
● Attaches an arbitrary name to an object (usually a commit)
● Commonly used for releases
The Git Repository
and some day-to-day examples
The .git directory
The working directory
Committing a file
Committing a file
The git index
The git index
http://ericsink.com/vcbe/html/directed_acyclic_graphs.html
Remote Repositories, multiple branches, and merging
Remote repositories
Remote repositories
GitX-devhttp://rowanj.github.io/gitx/
TortoiseGithttps://code.google.com/p/tortoisegit/
GitHub.com
