git-annex/Git/Ref.hs
Joey Hess c924542e61 bup: Properly handle key names with spaces or other things that are not legal git refs.
Continue using the key name as bup ref name, to preserve backwards
compatability, unless it is an illegal git ref. In that case, use a sha256
of the key name instead.
2012-04-11 12:45:49 -04:00

92 lines
2.6 KiB
Haskell

{- git ref stuff
-
- Copyright 2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Git.Ref where
import Common
import Git
import Git.Command
import Data.Char (chr)
{- Converts a fully qualified git ref into a user-visible string. -}
describe :: Ref -> String
describe = show . base
{- Often git refs are fully qualified (eg: refs/heads/master).
- Converts such a fully qualified ref into a base ref (eg: master). -}
base :: Ref -> Ref
base = Ref . remove "refs/heads/" . remove "refs/remotes/" . show
where
remove prefix s
| prefix `isPrefixOf` s = drop (length prefix) s
| otherwise = s
{- Given a directory such as "refs/remotes/origin", and a ref such as
- refs/heads/master, yields a version of that ref under the directory,
- such as refs/remotes/origin/master. -}
under :: String -> Ref -> Ref
under dir r = Ref $ dir </> show (base r)
{- Checks if a ref exists. -}
exists :: Ref -> Repo -> IO Bool
exists ref = runBool "show-ref"
[Param "--verify", Param "-q", Param $ show ref]
{- Get the sha of a fully qualified git ref, if it exists. -}
sha :: Branch -> Repo -> IO (Maybe Sha)
sha branch repo = process <$> showref repo
where
showref = pipeRead [Param "show-ref",
Param "--hash", -- get the hash
Param $ show branch]
process [] = Nothing
process s = Just $ Ref $ firstLine s
{- List of (refs, branches) matching a given ref spec. -}
matching :: Ref -> Repo -> IO [(Ref, Branch)]
matching ref repo = do
r <- pipeRead [Param "show-ref", Param $ show ref] repo
return $ map gen (lines r)
where
gen l = let (r, b) = separate (== ' ') l in
(Ref r, Ref b)
{- List of (refs, branches) matching a given ref spec.
- Duplicate refs are filtered out. -}
matchingUniq :: Ref -> Repo -> IO [(Ref, Branch)]
matchingUniq ref repo = nubBy uniqref <$> matching ref repo
where
uniqref (a, _) (b, _) = a == b
{- Checks if a String is a legal git ref name.
-
- The rules for this are complex; see git-check-ref-format(1) -}
legal :: Bool -> String -> Bool
legal allowonelevel s = all (== False) illegal
where
illegal =
[ any ("." `isPrefixOf`) pathbits
, any (".lock" `isSuffixOf`) pathbits
, not allowonelevel && length pathbits < 2
, contains ".."
, any (\c -> contains [c]) illegalchars
, begins "/"
, ends "/"
, contains "//"
, ends "."
, contains "@{"
, null s
]
contains v = v `isInfixOf` s
ends v = v `isSuffixOf` s
begins v = v `isPrefixOf` s
pathbits = split "/" s
illegalchars = " ~^:?*[\\" ++ controlchars
controlchars = chr 0o177 : [chr 0 .. chr (0o40-1)]