git-annex/Git/Index.hs
Joey Hess 3f0eef4baa
v7 for all repositories
* Default to v7 for new repositories.
* Automatically upgrade v5 repositories to v7.
2019-08-30 14:09:14 -04:00

60 lines
1.6 KiB
Haskell

{- git index file stuff
-
- Copyright 2011-2018 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Git.Index where
import Common
import Git
import Utility.Env
import Utility.Env.Set
indexEnv :: String
indexEnv = "GIT_INDEX_FILE"
{- Gets value to set GIT_INDEX_FILE to. Input should be absolute path,
- or relative to the CWD.
-
- When relative, GIT_INDEX_FILE is interpreted by git as being
- relative to the top of the work tree of the git repository,
- not to the CWD. Worse, other environment variables (GIT_WORK_TREE)
- or git options (--work-tree) or configuration (core.worktree)
- can change what the relative path is interpreted relative to.
-
- So, an absolute path is the only safe option for this to return.
-}
indexEnvVal :: FilePath -> IO String
indexEnvVal = absPath
{- Forces git to use the specified index file.
-
- Returns an action that will reset back to the default
- index file.
-
- Warning: Not thread safe.
-}
override :: FilePath -> Repo -> IO (IO ())
override index _r = do
res <- getEnv var
val <- indexEnvVal index
setEnv var val True
return $ reset res
where
var = "GIT_INDEX_FILE"
reset (Just v) = setEnv indexEnv v True
reset _ = unsetEnv var
{- The normal index file. Does not check GIT_INDEX_FILE. -}
indexFile :: Repo -> FilePath
indexFile r = localGitDir r </> "index"
{- The index file git will currently use, checking GIT_INDEX_FILE. -}
currentIndexFile :: Repo -> IO FilePath
currentIndexFile r = fromMaybe (indexFile r) <$> getEnv indexEnv
{- Git locks the index by creating this file. -}
indexFileLock :: FilePath -> FilePath
indexFileLock f = f ++ ".lock"