Clean up handling of git directory and git worktree.

Baked into the code was an assumption that a repository's git directory
could be determined by adding ".git" to its work tree (or nothing for bare
repos). That fails when core.worktree, or GIT_DIR and GIT_WORK_TREE are
used to separate the two.

This was attacked at the type level, by storing the gitdir and worktree
separately, so Nothing for the worktree means a bare repo.

A complication arose because we don't learn where a repository is bare
until its configuration is read. So another Location type handles
repositories that have not had their config read yet. I am not entirely
happy with this being a Location type, rather than representing them
entirely separate from the Git type. The new code is not worse than the
old, but better types could enforce more safety.

Added support for core.worktree. Overriding it with -c isn't supported
because it's not really clear what to do if a git repo's config is read, is
not bare, and is then overridden to bare. What is the right git directory
in this case? I will worry about this if/when someone has a use case for
overriding core.worktree with -c. (See Git.Config.updateLocation)

Also removed and renamed some functions like gitDir and workTree that
misused git's terminology.

One minor regression is known: git annex add in a bare repository does not
print a nice error message, but runs git ls-files in a way that fails
earlier with a less nice error message. This is because before --work-tree
was always passed to git commands, even in a bare repo, while now it's not.
This commit is contained in:
Joey Hess 2012-05-18 16:38:26 -04:00
parent a2be4265bf
commit bb4f31a0ee
21 changed files with 144 additions and 104 deletions

77
Git.hs
View file

@ -3,7 +3,7 @@
- This is written to be completely independant of git-annex and should be
- suitable for other uses.
-
- Copyright 2010, 2011 Joey Hess <joey@kitenet.net>
- Copyright 2010-2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
@ -17,19 +17,17 @@ module Git (
repoIsUrl,
repoIsSsh,
repoIsHttp,
repoIsLocal,
repoIsLocalBare,
repoDescribe,
repoLocation,
workTree,
gitDir,
configTrue,
repoPath,
localGitDir,
attributes,
hookPath,
assertLocal,
) where
import qualified Data.Map as M
import Data.Char
import Network.URI (uriPath, uriScheme, unEscapeString)
import System.Posix.Files
@ -41,15 +39,34 @@ import Utility.FileMode
repoDescribe :: Repo -> String
repoDescribe Repo { remoteName = Just name } = name
repoDescribe Repo { location = Url url } = show url
repoDescribe Repo { location = Dir dir } = dir
repoDescribe Repo { location = Local { worktree = Just dir } } = dir
repoDescribe Repo { location = Local { gitdir = dir } } = dir
repoDescribe Repo { location = LocalUnknown dir } = dir
repoDescribe Repo { location = Unknown } = "UNKNOWN"
{- Location of the repo, either as a path or url. -}
repoLocation :: Repo -> String
repoLocation Repo { location = Url url } = show url
repoLocation Repo { location = Dir dir } = dir
repoLocation Repo { location = Local { worktree = Just dir } } = dir
repoLocation Repo { location = Local { gitdir = dir } } = dir
repoLocation Repo { location = LocalUnknown dir } = dir
repoLocation Repo { location = Unknown } = undefined
{- Path to a repository. For non-bare, this is the worktree, for bare,
- it's the gitdir, and for URL repositories, is the path on the remote
- host. -}
repoPath :: Repo -> FilePath
repoPath Repo { location = Url u } = unEscapeString $ uriPath u
repoPath Repo { location = Local { worktree = Just d } } = d
repoPath Repo { location = Local { gitdir = d } } = d
repoPath Repo { location = LocalUnknown dir } = dir
repoPath Repo { location = Unknown } = undefined
{- Path to a local repository's .git directory. -}
localGitDir :: Repo -> FilePath
localGitDir Repo { location = Local { gitdir = d } } = d
localGitDir _ = undefined
{- Some code needs to vary between URL and normal repos,
- or bare and non-bare, these functions help with that. -}
repoIsUrl :: Repo -> Bool
@ -74,11 +91,12 @@ repoIsHttp Repo { location = Url url }
| otherwise = False
repoIsHttp _ = False
configAvail ::Repo -> Bool
configAvail Repo { config = c } = c /= M.empty
repoIsLocal :: Repo -> Bool
repoIsLocal Repo { location = Local { } } = True
repoIsLocal _ = False
repoIsLocalBare :: Repo -> Bool
repoIsLocalBare r@(Repo { location = Dir _ }) = configAvail r && configBare r
repoIsLocalBare Repo { location = Local { worktree = Nothing } } = True
repoIsLocalBare _ = False
assertLocal :: Repo -> a -> a
@ -90,49 +108,18 @@ assertLocal repo action
]
| otherwise = action
configBare :: Repo -> Bool
configBare repo = maybe unknown (fromMaybe False . configTrue) $
M.lookup "core.bare" $ config repo
where
unknown = error $ "it is not known if git repo " ++
repoDescribe repo ++
" is a bare repository; config not read"
{- Path to a repository's gitattributes file. -}
attributes :: Repo -> FilePath
attributes repo
| configBare repo = workTree repo ++ "/info/.gitattributes"
| otherwise = workTree repo ++ "/.gitattributes"
{- Path to a repository's .git directory. -}
gitDir :: Repo -> FilePath
gitDir repo
| configBare repo = workTree repo
| otherwise = workTree repo </> ".git"
| repoIsLocalBare repo = repoPath repo ++ "/info/.gitattributes"
| otherwise = repoPath repo ++ "/.gitattributes"
{- Path to a given hook script in a repository, only if the hook exists
- and is executable. -}
hookPath :: String -> Repo -> IO (Maybe FilePath)
hookPath script repo = do
let hook = gitDir repo </> "hooks" </> script
let hook = localGitDir repo </> "hooks" </> script
ifM (catchBoolIO $ isexecutable hook)
( return $ Just hook , return Nothing )
where
isexecutable f = isExecutable . fileMode <$> getFileStatus f
{- Path to a repository's --work-tree, that is, its top.
-
- Note that for URL repositories, this is the path on the remote host. -}
workTree :: Repo -> FilePath
workTree Repo { location = Url u } = unEscapeString $ uriPath u
workTree Repo { location = Dir d } = d
workTree Repo { location = Unknown } = undefined
{- Checks if a string from git config is a true value. -}
configTrue :: String -> Maybe Bool
configTrue s
| s' == "true" = Just True
| s' == "false" = Just False
| otherwise = Nothing
where
s' = map toLower s