Documentation/repository-layout.txt

   1 git repository layout
   2 =====================
   3
   4 You may find these things in your git repository (`.git`
   5 directory for a repository associated with your working tree, or
   6 `'project'.git` directory for a public 'bare' repository).
   7
   8 objects::
   9         Object store associated with this repository.  Usually
  10         an object store is self sufficient (i.e. all the objects
  11         that are referred to by an object found in it are also
  12         found in it), but there are couple of ways to violate
  13         it.
  14 +
  15 . You could populate the repository by running a commit walker
  16 without `-a` option.  Depending on which options are given, you
  17 could have only commit objects without associated blobs and
  18 trees this way, for example.  A repository with this kind of
  19 incomplete object store is not suitable to be published to the
  20 outside world but sometimes useful for private repository.
  21 . You also could have an incomplete but locally usable repository
  22 by cloning shallowly.  See gitlink:git-clone[1].
  23 . You can be using `objects/info/alternates` mechanism, or
  24 `$GIT_ALTERNATE_OBJECT_DIRECTORIES` mechanism to 'borrow'
  25 objects from other object stores.  A repository with this kind
  26 of incomplete object store is not suitable to be published for
  27 use with dumb transports but otherwise is OK as long as
  28 `objects/info/alternates` points at the right object stores
  29 it borrows from.
  30
  31 objects/[0-9a-f][0-9a-f]::
  32         Traditionally, each object is stored in its own file.
  33         They are split into 256 subdirectories using the first
  34         two letters from its object name to keep the number of
  35         directory entries `objects` directory itself needs to
  36         hold.  Objects found here are often called 'unpacked'
  37         (or 'loose') objects.
  38
  39 objects/pack::
  40         Packs (files that store many object in compressed form,
  41         along with index files to allow them to be randomly
  42         accessed) are found in this directory.
  43
  44 objects/info::
  45         Additional information about the object store is
  46         recorded in this directory.
  47
  48 objects/info/packs::
  49         This file is to help dumb transports discover what packs
  50         are available in this object store.  Whenever a pack is
  51         added or removed, `git update-server-info` should be run
  52         to keep this file up-to-date if the repository is
  53         published for dumb transports.  `git repack` does this
  54         by default.
  55
  56 objects/info/alternates::
  57         This file records paths to alternate object stores that
  58         this object store borrows objects from, one pathname per
  59         line. Note that not only native Git tools use it locally,
  60         but the HTTP fetcher also tries to use it remotely; this
  61         will usually work if you have relative paths (relative
  62         to the object database, not to the repository!) in your
  63         alternates file, but it will not work if you use absolute
  64         paths unless the absolute path in filesystem and web URL
  65         is the same. See also 'objects/info/http-alternates'.
  66
  67 objects/info/http-alternates::
  68         This file records URLs to alternate object stores that
  69         this object store borrows objects from, to be used when
  70         the repository is fetched over HTTP.
  71
  72 refs::
  73         References are stored in subdirectories of this
  74         directory.  The `git prune` command knows to keep
  75         objects reachable from refs found in this directory and
  76         its subdirectories.
  77
  78 refs/heads/`name`::
  79         records tip-of-the-tree commit objects of branch `name`
  80
  81 refs/tags/`name`::
  82         records any object name (not necessarily a commit
  83         object, or a tag object that points at a commit object).
  84
  85 refs/remotes/`name`::
  86         records tip-of-the-tree commit objects of branches copied
  87         from a remote repository.
  88
  89 packed-refs::
  90         records the same information as refs/heads/, refs/tags/,
  91         and friends record in a more efficient way.  See
  92         gitlink:git-pack-refs[1].
  93
  94 HEAD::
  95         A symref (see glossary) to the `refs/heads/` namespace
  96         describing the currently active branch.  It does not mean
  97         much if the repository is not associated with any working tree
  98         (i.e. a 'bare' repository), but a valid git repository
  99         *must* have the HEAD file; some porcelains may use it to
 100         guess the designated "default" branch of the repository
 101         (usually 'master').  It is legal if the named branch
 102         'name' does not (yet) exist.  In some legacy setups, it is
 103         a symbolic link instead of a symref that points at the current
 104         branch.
 105 +
 106 HEAD can also record a specific commit directly, instead of
 107 being a symref to point at the current branch.  Such a state
 108 is often called 'detached HEAD', and almost all commands work
 109 identically as normal.  See gitlink:git-checkout[1] for
 110 details.
 111
 112 branches::
 113         A slightly deprecated way to store shorthands to be used
 114         to specify URL to `git fetch`, `git pull` and `git push`
 115         commands is to store a file in `branches/'name'` and
 116         give 'name' to these commands in place of 'repository'
 117         argument.
 118
 119 hooks::
 120         Hooks are customization scripts used by various git
 121         commands.  A handful of sample hooks are installed when
 122         `git init` is run, but all of them are disabled by
 123         default.  To enable, they need to be made executable.
 124         Read link:hooks.html[hooks] for more details about
 125         each hook.
 126
 127 index::
 128         The current index file for the repository.  It is
 129         usually not found in a bare repository.
 130
 131 info::
 132         Additional information about the repository is recorded
 133         in this directory.
 134
 135 info/refs::
 136         This file helps dumb transports discover what refs are
 137         available in this repository.  If the repository is
 138         published for dumb transports, this file should be
 139         regenerated by `git update-server-info` every time a tag
 140         or branch is created or modified.  This is normally done
 141         from the `hooks/update` hook, which is run by the
 142         `git-receive-pack` command when you `git push` into the
 143         repository.
 144
 145 info/grafts::
 146         This file records fake commit ancestry information, to
 147         pretend the set of parents a commit has is different
 148         from how the commit was actually created.  One record
 149         per line describes a commit and its fake parents by
 150         listing their 40-byte hexadecimal object names separated
 151         by a space and terminated by a newline.
 152
 153 info/exclude::
 154         This file, by convention among Porcelains, stores the
 155         exclude pattern list. `.gitignore` is the per-directory
 156         ignore file.  `git status`, `git add`, `git rm` and `git
 157         clean` look at it but the core git commands do not look
 158         at it.  See also: gitlink:gitignore[5].
 159
 160 remotes::
 161         Stores shorthands to be used to give URL and default
 162         refnames to interact with remote repository to `git
 163         fetch`, `git pull` and `git push` commands.
 164
 165 logs::
 166         Records of changes made to refs are stored in this
 167         directory.  See the documentation on git-update-ref
 168         for more information.
 169
 170 logs/refs/heads/`name`::
 171         Records all changes made to the branch tip named `name`.
 172
 173 logs/refs/tags/`name`::
 174         Records all changes made to the tag named `name`.
 175
 176 shallow::
 177         This is similar to `info/grafts` but is internally used
 178         and maintained by shallow clone mechanism.  See `--depth`
 179         option to gitlink:git-clone[1] and gitlink:git-fetch[1].
 180