[thirdparty/git.git] / Documentation / repository-layout.txt

GIT repository layout
=====================
v0.99.5, Sep 2005

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 'naked' 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 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 incompete 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'
	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 absolute filesystem paths of alternate
	object stores that this object store borrows objects
	from, one pathname per line.

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).

HEAD::
	A symlink of the form `refs/heads/'name'` to point at
	the current branch, if exists.  It does not mean much if
	the repository is not associated with any working tree
	(i.e. 'naked' repository), but a valid git repository
	*must* have such a symlink here.  It is legal if the
	named branch 'name' does not (yet) exist.

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-db` is run, but all of them are disabled by
	default.  To enable, they need to be made executable.

index::
	The current index file for the repository.  It is
	usually not found in a naked repository.

info::
	Additional information about the repository is recorded
	in this directory.

info/refs::
	This file is to help dumb transports to discover what
	refs are available in this repository.  Whenever you
	create/delete a new branch or a new tag, `git
	update-server-info` should be run to keep this file
	up-to-date if the repository is published for dumb
	transports.  The `git-receive-pack` command, which is
	run on a remote repository when you `git push` into it,
	runs `hooks/update` hook to help you achive this.

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/rev-cache::
	No higher-level tool currently takes advantage of this
	file, but it is generated when `git update-server-info`
	is run.  It records the commit ancestry information of
	the commits in this repository in a concise binary
	format, and can be read with `git-show-rev-cache`.

info/exclude::
	This file, by convention among Porcelains, stores the
	exclude pattern list.  `git status` looks at it, but
	otherwise it is not looked at by any of the core GIT
	commands.

remotes::
	Stoers shorthands to be used to give URL and default
	refnames to interact with remote repository to `git
	fetch`, `git pull` and `git push` commands.
Commit	Line	Data
a1d4aa74 JH	1	GIT repository layout
	2	=====================
	3	v0.99.5, Sep 2005
	4
	5	You may find these things in your git repository (`.git`
	6	directory for a repository associated with your working tree, or
	7	`'project'.git` directory for a public 'naked' repository).
	8
	9	objects::
	10	Object store associated with this repository. Usually
	11	an object store is self sufficient (i.e. all the objects
	12	that are referred to by an object found in it are also
	13	found in it), but there are couple of ways to violate
	14	it.
	15	+
	16	. You could populate the repository by running a commit walker
	17	without `-a` option. Depending on which options are given, you
	18	could have only commit objects without associated blobs and
	19	trees this way, for example. A repository with this kind of
	20	incomplete object store is not suitable to be published to the
	21	outside world but sometimes useful for private repository.
	22	. You can be using `objects/info/alternates` mechanism, or
	23	`$GIT_ALTERNATE_OBJECT_DIRECTORIES` mechanism to 'borrow'
	24	objects from other object stores. A repository with this kind
	25	of incompete object store is not suitable to be published for
	26	use with dumb transports but otherwise is OK as long as
	27	`objects/info/alternates` points at the right object stores
	28	it borrows from.
	29
	30	objects/[0-9a-f][0-9a-f]::
	31	Traditionally, each object is stored in its own file.
	32	They are split into 256 subdirectories using the first
	33	two letters from its object name to keep the number of
	34	directory entries `objects` directory itself needs to
	35	hold. Objects found here are often called 'unpacked'
	36	objects.
	37
	38	objects/pack::
	39	Packs (files that store many object in compressed form,
	40	along with index files to allow them to be randomly
	41	accessed) are found in this directory.
	42
	43	objects/info::
	44	Additional information about the object store is
	45	recorded in this directory.
	46
	47	objects/info/packs::
	48	This file is to help dumb transports discover what packs
	49	are available in this object store. Whenever a pack is
	50	added or removed, `git update-server-info` should be run
	51	to keep this file up-to-date if the repository is
	52	published for dumb transports. `git repack` does this
	53	by default.
	54
	55	objects/info/alternates::
	56	This file records absolute filesystem paths of alternate
	57	object stores that this object store borrows objects
	58	from, one pathname per line.
	59
	60	refs::
	61	References are stored in subdirectories of this
	62	directory. The `git prune` command knows to keep
	63	objects reachable from refs found in this directory and
	64	its subdirectories.
65
66	refs/heads/`name`::
67	records tip-of-the-tree commit objects of branch `name`
68
69	refs/tags/`name`::
70	records any object name (not necessarily a commit
71	object, or a tag object that points at a commit object).
72
73	HEAD::
74	A symlink of the form `refs/heads/'name'` to point at
75	the current branch, if exists. It does not mean much if
76	the repository is not associated with any working tree
77	(i.e. 'naked' repository), but a valid git repository
78	must have such a symlink here. It is legal if the
79	named branch 'name' does not (yet) exist.
80
81	branches::
82	A slightly deprecated way to store shorthands to be used
83	to specify URL to `git fetch`, `git pull` and `git push`
84	commands is to store a file in `branches/'name'` and
85	give 'name' to these commands in place of 'repository'
86	argument.
87
88	hooks::
89	Hooks are customization scripts used by various git
90	commands. A handful of sample hooks are installed when
91	`git init-db` is run, but all of them are disabled by
92	default. To enable, they need to be made executable.
93
94	index::
95	The current index file for the repository. It is
96	usually not found in a naked repository.
97
98	info::
99	Additional information about the repository is recorded
100	in this directory.
101
102	info/refs::
103	This file is to help dumb transports to discover what
104	refs are available in this repository. Whenever you
105	create/delete a new branch or a new tag, `git
106	update-server-info` should be run to keep this file
107	up-to-date if the repository is published for dumb
108	transports. The `git-receive-pack` command, which is
109	run on a remote repository when you `git push` into it,
110	runs `hooks/update` hook to help you achive this.
111
112	info/grafts::
113	This file records fake commit ancestry information, to
114	pretend the set of parents a commit has is different
115	from how the commit was actually created. One record
116	per line describes a commit and its fake parents by
117	listing their 40-byte hexadecimal object names separated
118	by a space and terminated by a newline.
119
120	info/rev-cache::
121	No higher-level tool currently takes advantage of this
122	file, but it is generated when `git update-server-info`
123	is run. It records the commit ancestry information of
124	the commits in this repository in a concise binary
125	format, and can be read with `git-show-rev-cache`.
126
127	info/exclude::
128	This file, by convention among Porcelains, stores the
129	exclude pattern list. `git status` looks at it, but
130	otherwise it is not looked at by any of the core GIT
131	commands.
132
133	remotes::
134	Stoers shorthands to be used to give URL and default
135	refnames to interact with remote repository to `git
136	fetch`, `git pull` and `git push` commands.