1 files changed, 181 insertions, 0 deletions
diff --git a/Documentation/repository-layout.txt b/Documentation/repository-layout.txt
new file mode 100644
index 0000000000..0459bd9ca1
--- /dev/null
+++ b/Documentation/repository-layout.txt
@@ -0,0 +1,181 @@
+git repository layout
+=====================
+
+You may find these things in your git repository (`.git`
+directory for a repository associated with your working tree, or
+`'project'.git` directory for a public 'bare' repository).
+
+objects::
+	Object store associated with this repository.  Usually
+	an object store is self sufficient (i.e. all the objects
+	that are referred to by an object found in it are also
+	found in it), but there are couple of ways to violate
+	it.
++
+. You could populate the repository by running a commit walker
+without `-a` option.  Depending on which options are given, you
+could have only commit objects without associated blobs and
+trees this way, for example.  A repository with this kind of
+incomplete object store is not suitable to be published to the
+outside world but sometimes useful for private repository.
+. You also could have an incomplete but locally usable repository
+by cloning shallowly.  See gitlink:git-clone[1].
+. You can be using `objects/info/alternates` mechanism, or
+`$GIT_ALTERNATE_OBJECT_DIRECTORIES` mechanism to 'borrow'
+objects from other object stores.  A repository with this kind
+of incomplete object store is not suitable to be published for
+use with dumb transports but otherwise is OK as long as
+`objects/info/alternates` points at the right object stores
+it borrows from.
+
+objects/[0-9a-f][0-9a-f]::
+	Traditionally, each object is stored in its own file.
+	They are split into 256 subdirectories using the first
+	two letters from its object name to keep the number of
+	directory entries `objects` directory itself needs to
+	hold.  Objects found here are often called 'unpacked'
+	(or 'loose') objects.
+
+objects/pack::
+	Packs (files that store many object in compressed form,
+	along with index files to allow them to be randomly
+	accessed) are found in this directory.
+
+objects/info::
+	Additional information about the object store is
+	recorded in this directory.
+
+objects/info/packs::
+	This file is to help dumb transports discover what packs
+	are available in this object store.  Whenever a pack is
+	added or removed, `git update-server-info` should be run
+	to keep this file up-to-date if the repository is
+	published for dumb transports.  `git repack` does this
+	by default.
+
+objects/info/alternates::
+	This file records paths to alternate object stores that
+	this object store borrows objects from, one pathname per
+	line. Note that not only native Git tools use it locally,
+	but the HTTP fetcher also tries to use it remotely; this
+	will usually work if you have relative paths (relative
+	to the object database, not to the repository!) in your
+	alternates file, but it will not work if you use absolute
+	paths unless the absolute path in filesystem and web URL
+	is the same. See also 'objects/info/http-alternates'.
+
+objects/info/http-alternates::
+	This file records URLs to alternate object stores that
+	this object store borrows objects from, to be used when
+	the repository is fetched over HTTP.
+
+refs::
+	References are stored in subdirectories of this
+	directory.  The `git prune` command knows to keep
+	objects reachable from refs found in this directory and
+	its subdirectories.
+
+refs/heads/`name`::
+	records tip-of-the-tree commit objects of branch `name`
+
+refs/tags/`name`::
+	records any object name (not necessarily a commit
+	object, or a tag object that points at a commit object).
+
+refs/remotes/`name`::
+	records tip-of-the-tree commit objects of branches copied
+	from a remote repository.
+
+packed-refs::
+	records the same information as refs/heads/, refs/tags/,
+	and friends record in a more efficient way.  See
+	gitlink:git-pack-refs[1].
+
+HEAD::
+	A symref (see glossary) to the `refs/heads/` namespace
+	describing the currently active branch.  It does not mean
+	much if the repository is not associated with any working tree
+	(i.e. a 'bare' repository), but a valid git repository
+	*must* have the HEAD file; some porcelains may use it to
+	guess the designated "default" branch of the repository
+	(usually 'master').  It is legal if the named branch
+	'name' does not (yet) exist.  In some legacy setups, it is
+	a symbolic link instead of a symref that points at the current
+	branch.
++
+HEAD can also record a specific commit directly, instead of
+being a symref to point at the current branch.  Such a state
+is often called 'detached HEAD', and almost all commands work
+identically as normal.  See gitlink:git-checkout[1] for
+details.
+
+branches::
+	A slightly deprecated way to store shorthands to be used
+	to specify URL to `git fetch`, `git pull` and `git push`
+	commands is to store a file in `branches/'name'` and
+	give 'name' to these commands in place of 'repository'
+	argument.
+
+hooks::
+	Hooks are customization scripts used by various git
+	commands.  A handful of sample hooks are installed when
+	`git init` is run, but all of them are disabled by
+	default.  To enable, they need to be made executable.
+	Read link:hooks.html[hooks] for more details about
+	each hook.
+
+index::
+	The current index file for the repository.  It is
+	usually not found in a bare repository.
+
+info::
+	Additional information about the repository is recorded
+	in this directory.
+
+info/refs::
+	This file helps dumb transports discover what refs are
+	available in this repository.  If the repository is
+	published for dumb transports, this file should be
+	regenerated by `git update-server-info` every time a tag
+	or branch is created or modified.  This is normally done
+	from the `hooks/update` hook, which is run by the
+	`git-receive-pack` command when you `git push` into the
+	repository.
+
+info/grafts::
+	This file records fake commit ancestry information, to
+	pretend the set of parents a commit has is different
+	from how the commit was actually created.  One record
+	per line describes a commit and its fake parents by
+	listing their 40-byte hexadecimal object names separated
+	by a space and terminated by a newline.
+
+info/exclude::
+	This file, by convention among Porcelains, stores the
+	exclude pattern list. `.gitignore` is the per-directory
+	ignore file.  `git status`, `git add`, `git rm` and `git
+	clean` look at it but the core git commands do not look
+	at it.  See also: gitlink:git-ls-files[1] `--exclude-from`
+	and `--exclude-per-directory`.
+
+remotes::
+	Stores shorthands to be used to give URL and default
+	refnames to interact with remote repository to `git
+	fetch`, `git pull` and `git push` commands.
+
+logs::
+	Records of changes made to refs are stored in this
+	directory.  See the documentation on git-update-ref
+	for more information.
+
+logs/refs/heads/`name`::
+	Records all changes made to the branch tip named `name`.
+
+logs/refs/tags/`name`::
+	Records all changes made to the tag named `name`.
+
+shallow::
+	This is similar to `info/grafts` but is internally used
+	and maintained by shallow clone mechanism.  See `--depth`
+	option to gitlink:git-clone[1] and gitlink:git-fetch[1].
+