git-annex/Git/Construct.hs
Joey Hess be028f10e5
split out Utility.Url.Parse
This is mostly for git-repair which can't include all of Utility.Url
without adding many dependencies that are not really necessary.
2023-08-14 12:28:10 -04:00

291 lines
8.6 KiB
Haskell

{- Construction of Git Repo objects
-
- Copyright 2010-2023 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE CPP #-}
module Git.Construct (
fromCwd,
fromAbsPath,
fromPath,
fromUrl,
fromUnknown,
localToUrl,
remoteNamed,
remoteNamedFromKey,
fromRemotes,
fromRemoteLocation,
repoAbsPath,
checkForRepo,
newFrom,
adjustGitDirFile,
isBareRepo,
) where
#ifndef mingw32_HOST_OS
import System.Posix.User
#endif
import qualified Data.Map as M
import Network.URI
import Common
import Git.Types
import Git
import Git.Remote
import Git.FilePath
import qualified Git.Url as Url
import Utility.UserInfo
import Utility.Url.Parse
import qualified Data.ByteString as B
import qualified System.FilePath.ByteString as P
{- Finds the git repository used for the cwd, which may be in a parent
- directory. -}
fromCwd :: IO (Maybe Repo)
fromCwd = getCurrentDirectory >>= seekUp
where
seekUp dir = do
r <- checkForRepo dir
case r of
Nothing -> case upFrom (toRawFilePath dir) of
Nothing -> return Nothing
Just d -> seekUp (fromRawFilePath d)
Just loc -> pure $ Just $ newFrom loc
{- Local Repo constructor, accepts a relative or absolute path. -}
fromPath :: RawFilePath -> IO Repo
fromPath dir
-- When dir == "foo/.git", git looks for "foo/.git/.git",
-- and failing that, uses "foo" as the repository.
| (P.pathSeparator `B.cons` ".git") `B.isSuffixOf` canondir =
ifM (doesDirectoryExist $ fromRawFilePath dir </> ".git")
( ret dir
, ret (P.takeDirectory canondir)
)
| otherwise = ifM (doesDirectoryExist (fromRawFilePath dir))
( checkGitDirFile dir >>= maybe (ret dir) (pure . newFrom)
-- git falls back to dir.git when dir doesn't
-- exist, as long as dir didn't end with a
-- path separator
, if dir == canondir
then ret (dir <> ".git")
else ret dir
)
where
ret = pure . newFrom . LocalUnknown
canondir = P.dropTrailingPathSeparator dir
{- Local Repo constructor, requires an absolute path to the repo be
- specified. -}
fromAbsPath :: RawFilePath -> IO Repo
fromAbsPath dir
| absoluteGitPath dir = fromPath dir
| otherwise =
giveup $ "internal error, " ++ show dir ++ " is not absolute"
{- Construct a Repo for a remote's url.
-
- Git is somewhat forgiving about urls to repositories, allowing
- eg spaces that are not normally allowed unescaped in urls. Such
- characters get escaped.
-
- This will always succeed, even if the url cannot be parsed
- or is invalid, because git can also function despite remotes having
- such urls, only failing if such a remote is used.
-}
fromUrl :: String -> IO Repo
fromUrl url
| not (isURI url) = fromUrl' $ escapeURIString isUnescapedInURI url
| otherwise = fromUrl' url
fromUrl' :: String -> IO Repo
fromUrl' url
| "file://" `isPrefixOf` url = case parseURIPortable url of
Just u -> fromAbsPath $ toRawFilePath $ unEscapeString $ uriPath u
Nothing -> pure $ newFrom $ UnparseableUrl url
| otherwise = case parseURIPortable url of
Just u -> pure $ newFrom $ Url u
Nothing -> pure $ newFrom $ UnparseableUrl url
{- Creates a repo that has an unknown location. -}
fromUnknown :: Repo
fromUnknown = newFrom Unknown
{- Converts a local Repo into a remote repo, using the reference repo
- which is assumed to be on the same host. -}
localToUrl :: Repo -> Repo -> Repo
localToUrl reference r
| not $ repoIsUrl reference = error "internal error; reference repo not url"
| repoIsUrl r = r
| otherwise = case (Url.authority reference, Url.scheme reference) of
(Just auth, Just s) ->
let absurl = concat
[ s
, "//"
, auth
, fromRawFilePath (repoPath r)
]
in r { location = Url $ fromJust $ parseURIPortable absurl }
_ -> r
{- Calculates a list of a repo's configured remotes, by parsing its config. -}
fromRemotes :: Repo -> IO [Repo]
fromRemotes repo = catMaybes <$> mapM construct remotepairs
where
filterconfig f = filter f $ M.toList $ config repo
filterkeys f = filterconfig (\(k,_) -> f k)
remotepairs = filterkeys isRemoteUrlKey
construct (k,v) = remoteNamedFromKey k $
fromRemoteLocation (fromConfigValue v) False repo
{- Sets the name of a remote when constructing the Repo to represent it. -}
remoteNamed :: String -> IO Repo -> IO Repo
remoteNamed n constructor = do
r <- constructor
return $ r { remoteName = Just n }
{- Sets the name of a remote based on the git config key, such as
- "remote.foo.url". -}
remoteNamedFromKey :: ConfigKey -> IO Repo -> IO (Maybe Repo)
remoteNamedFromKey k r = case remoteKeyToRemoteName k of
Nothing -> pure Nothing
Just n -> Just <$> remoteNamed n r
{- Constructs a new Repo for one of a Repo's remotes using a given
- location (ie, an url).
-
- knownurl can be true if the location is known to be an url. This allows
- urls that don't parse as urls to be used, returning UnparseableUrl.
- If knownurl is false, the location may still be an url, if it parses as
- one.
-}
fromRemoteLocation :: String -> Bool -> Repo -> IO Repo
fromRemoteLocation s knownurl repo = gen $ parseRemoteLocation s knownurl repo
where
gen (RemotePath p) = fromRemotePath p repo
gen (RemoteUrl u) = fromUrl u
{- Constructs a Repo from the path specified in the git remotes of
- another Repo. -}
fromRemotePath :: FilePath -> Repo -> IO Repo
fromRemotePath dir repo = do
dir' <- expandTilde dir
fromPath $ repoPath repo P.</> toRawFilePath dir'
{- Git remotes can have a directory that is specified relative
- to the user's home directory, or that contains tilde expansions.
- This converts such a directory to an absolute path.
- Note that it has to run on the system where the remote is.
-}
repoAbsPath :: RawFilePath -> IO RawFilePath
repoAbsPath d = do
d' <- expandTilde (fromRawFilePath d)
h <- myHomeDir
return $ toRawFilePath $ h </> d'
expandTilde :: FilePath -> IO FilePath
#ifdef mingw32_HOST_OS
expandTilde = return
#else
expandTilde p = expandt True p
-- If unable to expand a tilde, eg due to a user not existing,
-- use the path as given.
`catchNonAsync` (const (return p))
where
expandt _ [] = return ""
expandt _ ('/':cs) = do
v <- expandt True cs
return ('/':v)
expandt True ('~':'/':cs) = do
h <- myHomeDir
return $ h </> cs
expandt True "~" = myHomeDir
expandt True ('~':cs) = do
let (name, rest) = findname "" cs
u <- getUserEntryForName name
return $ homeDirectory u </> rest
expandt _ (c:cs) = do
v <- expandt False cs
return (c:v)
findname n [] = (n, "")
findname n (c:cs)
| c == '/' = (n, cs)
| otherwise = findname (n++[c]) cs
#endif
{- Checks if a git repository exists in a directory. Does not find
- git repositories in parent directories. -}
checkForRepo :: FilePath -> IO (Maybe RepoLocation)
checkForRepo dir =
check isRepo $
check (checkGitDirFile (toRawFilePath dir)) $
check (checkdir (isBareRepo dir)) $
return Nothing
where
check test cont = maybe cont (return . Just) =<< test
checkdir c = ifM c
( return $ Just $ LocalUnknown $ toRawFilePath dir
, return Nothing
)
isRepo = checkdir $
doesFileExist (dir </> ".git" </> "config")
<||>
-- A git-worktree lacks .git/config, but has .git/gitdir.
-- (Normally the .git is a file, not a symlink, but it can
-- be converted to a symlink and git will still work;
-- this handles that case.)
doesFileExist (dir </> ".git" </> "gitdir")
isBareRepo :: FilePath -> IO Bool
isBareRepo dir = doesFileExist (dir </> "config")
<&&> doesDirectoryExist (dir </> "objects")
-- Check for a .git file.
checkGitDirFile :: RawFilePath -> IO (Maybe RepoLocation)
checkGitDirFile dir = adjustGitDirFile' $ Local
{ gitdir = dir P.</> ".git"
, worktree = Just dir
}
-- git-submodule, git-worktree, and --separate-git-dir
-- make .git be a file pointing to the real git directory.
-- Detect that, and return a RepoLocation with gitdir pointing
-- to the real git directory.
adjustGitDirFile :: RepoLocation -> IO RepoLocation
adjustGitDirFile loc = fromMaybe loc <$> adjustGitDirFile' loc
adjustGitDirFile' :: RepoLocation -> IO (Maybe RepoLocation)
adjustGitDirFile' loc = do
let gd = gitdir loc
c <- firstLine <$> catchDefaultIO "" (readFile (fromRawFilePath gd))
if gitdirprefix `isPrefixOf` c
then do
top <- fromRawFilePath . P.takeDirectory <$> absPath gd
return $ Just $ loc
{ gitdir = absPathFrom
(toRawFilePath top)
(toRawFilePath
(drop (length gitdirprefix) c))
}
else return Nothing
where
gitdirprefix = "gitdir: "
newFrom :: RepoLocation -> Repo
newFrom l = Repo
{ location = l
, config = M.empty
, fullconfig = M.empty
, remoteName = Nothing
, gitEnv = Nothing
, gitEnvOverridesGitDir = False
, gitGlobalOpts = []
, gitDirSpecifiedExplicitly = False
}