Documentation / gitrepository-layout.txton commit Preallocate hash tables when the number of inserts are known in advance (c735928)
   1gitrepository-layout(5)
   2=======================
   3
   4NAME
   5----
   6gitrepository-layout - Git Repository Layout
   7
   8SYNOPSIS
   9--------
  10$GIT_DIR/*
  11
  12DESCRIPTION
  13-----------
  14
  15You may find these things in your git repository (`.git`
  16directory for a repository associated with your working tree, or
  17`<project>.git` directory for a public 'bare' repository. It is
  18also possible to have a working tree where `.git` is a plain
  19ASCII file containing `gitdir: <path>`, i.e. the path to the
  20real git repository).
  21
  22objects::
  23        Object store associated with this repository.  Usually
  24        an object store is self sufficient (i.e. all the objects
  25        that are referred to by an object found in it are also
  26        found in it), but there are a few ways to violate it.
  27+
  28. You could have an incomplete but locally usable repository
  29by creating a shallow clone.  See linkgit:git-clone[1].
  30. You could be using the `objects/info/alternates` or
  31`$GIT_ALTERNATE_OBJECT_DIRECTORIES` mechanisms to 'borrow'
  32objects from other object stores.  A repository with this kind
  33of incomplete object store is not suitable to be published for
  34use with dumb transports but otherwise is OK as long as
  35`objects/info/alternates` points at the object stores it
  36borrows from.
  37
  38objects/[0-9a-f][0-9a-f]::
  39        A newly created object is stored in its own file.
  40        The objects are splayed over 256 subdirectories using
  41        the first two characters of the sha1 object name to
  42        keep the number of directory entries in `objects`
  43        itself to a manageable number. Objects found
  44        here are often called 'unpacked' (or 'loose') objects.
  45
  46objects/pack::
  47        Packs (files that store many object in compressed form,
  48        along with index files to allow them to be randomly
  49        accessed) are found in this directory.
  50
  51objects/info::
  52        Additional information about the object store is
  53        recorded in this directory.
  54
  55objects/info/packs::
  56        This file is to help dumb transports discover what packs
  57        are available in this object store.  Whenever a pack is
  58        added or removed, `git update-server-info` should be run
  59        to keep this file up-to-date if the repository is
  60        published for dumb transports.  'git repack' does this
  61        by default.
  62
  63objects/info/alternates::
  64        This file records paths to alternate object stores that
  65        this object store borrows objects from, one pathname per
  66        line. Note that not only native Git tools use it locally,
  67        but the HTTP fetcher also tries to use it remotely; this
  68        will usually work if you have relative paths (relative
  69        to the object database, not to the repository!) in your
  70        alternates file, but it will not work if you use absolute
  71        paths unless the absolute path in filesystem and web URL
  72        is the same. See also 'objects/info/http-alternates'.
  73
  74objects/info/http-alternates::
  75        This file records URLs to alternate object stores that
  76        this object store borrows objects from, to be used when
  77        the repository is fetched over HTTP.
  78
  79refs::
  80        References are stored in subdirectories of this
  81        directory.  The 'git prune' command knows to preserve
  82        objects reachable from refs found in this directory and
  83        its subdirectories.
  84
  85refs/heads/`name`::
  86        records tip-of-the-tree commit objects of branch `name`
  87
  88refs/tags/`name`::
  89        records any object name (not necessarily a commit
  90        object, or a tag object that points at a commit object).
  91
  92refs/remotes/`name`::
  93        records tip-of-the-tree commit objects of branches copied
  94        from a remote repository.
  95
  96refs/replace/`<obj-sha1>`::
  97        records the SHA1 of the object that replaces `<obj-sha1>`.
  98        This is similar to info/grafts and is internally used and
  99        maintained by linkgit:git-replace[1]. Such refs can be exchanged
 100        between repositories while grafts are not.
 101
 102packed-refs::
 103        records the same information as refs/heads/, refs/tags/,
 104        and friends record in a more efficient way.  See
 105        linkgit:git-pack-refs[1].
 106
 107HEAD::
 108        A symref (see glossary) to the `refs/heads/` namespace
 109        describing the currently active branch.  It does not mean
 110        much if the repository is not associated with any working tree
 111        (i.e. a 'bare' repository), but a valid git repository
 112        *must* have the HEAD file; some porcelains may use it to
 113        guess the designated "default" branch of the repository
 114        (usually 'master').  It is legal if the named branch
 115        'name' does not (yet) exist.  In some legacy setups, it is
 116        a symbolic link instead of a symref that points at the current
 117        branch.
 118+
 119HEAD can also record a specific commit directly, instead of
 120being a symref to point at the current branch.  Such a state
 121is often called 'detached HEAD.'  See linkgit:git-checkout[1]
 122for details.
 123
 124branches::
 125        A slightly deprecated way to store shorthands to be used
 126        to specify a URL to 'git fetch', 'git pull' and 'git push'.
 127        A file can be stored as `branches/<name>` and then
 128        'name' can be given to these commands in place of
 129        'repository' argument.  See the REMOTES section in
 130        linkgit:git-fetch[1] for details.  This mechanism is legacy
 131        and not likely to be found in modern repositories.
 132
 133hooks::
 134        Hooks are customization scripts used by various git
 135        commands.  A handful of sample hooks are installed when
 136        'git init' is run, but all of them are disabled by
 137        default.  To enable, the `.sample` suffix has to be
 138        removed from the filename by renaming.
 139        Read linkgit:githooks[5] for more details about
 140        each hook.
 141
 142index::
 143        The current index file for the repository.  It is
 144        usually not found in a bare repository.
 145
 146info::
 147        Additional information about the repository is recorded
 148        in this directory.
 149
 150info/refs::
 151        This file helps dumb transports discover what refs are
 152        available in this repository.  If the repository is
 153        published for dumb transports, this file should be
 154        regenerated by 'git update-server-info' every time a tag
 155        or branch is created or modified.  This is normally done
 156        from the `hooks/update` hook, which is run by the
 157        'git-receive-pack' command when you 'git push' into the
 158        repository.
 159
 160info/grafts::
 161        This file records fake commit ancestry information, to
 162        pretend the set of parents a commit has is different
 163        from how the commit was actually created.  One record
 164        per line describes a commit and its fake parents by
 165        listing their 40-byte hexadecimal object names separated
 166        by a space and terminated by a newline.
 167
 168info/exclude::
 169        This file, by convention among Porcelains, stores the
 170        exclude pattern list. `.gitignore` is the per-directory
 171        ignore file.  'git status', 'git add', 'git rm' and
 172        'git clean' look at it but the core git commands do not look
 173        at it.  See also: linkgit:gitignore[5].
 174
 175remotes::
 176        Stores shorthands for URL and default refnames for use
 177        when interacting with remote repositories via 'git fetch',
 178        'git pull' and 'git push' commands.  See the REMOTES section
 179        in linkgit:git-fetch[1] for details.  This mechanism is legacy
 180        and not likely to be found in modern repositories.
 181
 182logs::
 183        Records of changes made to refs are stored in this
 184        directory.  See linkgit:git-update-ref[1]
 185        for more information.
 186
 187logs/refs/heads/`name`::
 188        Records all changes made to the branch tip named `name`.
 189
 190logs/refs/tags/`name`::
 191        Records all changes made to the tag named `name`.
 192
 193shallow::
 194        This is similar to `info/grafts` but is internally used
 195        and maintained by shallow clone mechanism.  See `--depth`
 196        option to linkgit:git-clone[1] and linkgit:git-fetch[1].
 197
 198SEE ALSO
 199--------
 200linkgit:git-init[1],
 201linkgit:git-clone[1],
 202linkgit:git-fetch[1],
 203linkgit:git-pack-refs[1],
 204linkgit:git-gc[1],
 205linkgit:git-checkout[1],
 206linkgit:gitglossary[7],
 207link:user-manual.html[The Git User's Manual]
 208
 209GIT
 210---
 211Part of the linkgit:git[1] suite.