ec267aa1ea
The explict import Prelude after import Control.Applicative is a trick to avoid a warning.
90 lines
2.7 KiB
Haskell
90 lines
2.7 KiB
Haskell
{- git-annex repository differences
|
|
-
|
|
- Copyright 2015 Joey Hess <id@joeyh.name>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
module Types.Difference (
|
|
Difference(..),
|
|
Differences(..),
|
|
readDifferences,
|
|
getDifferences,
|
|
differenceConfigKey,
|
|
differenceConfigVal,
|
|
hasDifference,
|
|
listDifferences,
|
|
) where
|
|
|
|
import Utility.PartialPrelude
|
|
import qualified Git
|
|
import qualified Git.Config
|
|
|
|
import qualified Data.Set as S
|
|
import Data.Maybe
|
|
import Data.Monoid
|
|
import Prelude
|
|
|
|
-- Describes differences from the v5 repository format.
|
|
--
|
|
-- The serialization is stored in difference.log, so avoid changes that
|
|
-- would break compatability.
|
|
--
|
|
-- Not breaking compatability is why a list of Differences is used, rather
|
|
-- than a sum type. With a sum type, adding a new field for some future
|
|
-- difference would serialize to a value that an older version could not
|
|
-- parse, even if that new field was not used. With the Differences list,
|
|
-- old versions can still parse it, unless the new Difference constructor
|
|
-- is used.
|
|
--
|
|
-- The constructors intentionally do not have parameters; this is to
|
|
-- ensure that any Difference that can be expressed is supported.
|
|
-- So, a new repository version would be Version6, rather than Version Int.
|
|
data Difference
|
|
= ObjectHashLower
|
|
| OneLevelObjectHash
|
|
| OneLevelBranchHash
|
|
deriving (Show, Read, Ord, Eq, Enum, Bounded)
|
|
|
|
data Differences
|
|
= Differences (S.Set Difference)
|
|
| UnknownDifferences
|
|
|
|
instance Eq Differences where
|
|
Differences a == Differences b = a == b
|
|
_ == _ = False -- UnknownDifferences cannot be equal
|
|
|
|
instance Monoid Differences where
|
|
mempty = Differences S.empty
|
|
mappend (Differences a) (Differences b) = Differences (S.union a b)
|
|
mappend _ _ = UnknownDifferences
|
|
|
|
readDifferences :: String -> Differences
|
|
readDifferences = maybe UnknownDifferences Differences . readish
|
|
|
|
getDifferences :: Git.Repo -> Differences
|
|
getDifferences r = Differences $ S.fromList $
|
|
mapMaybe getmaybe [minBound .. maxBound]
|
|
where
|
|
getmaybe d = case Git.Config.isTrue =<< Git.Config.getMaybe (differenceConfigKey d) r of
|
|
Just True -> Just d
|
|
_ -> Nothing
|
|
|
|
differenceConfigKey :: Difference -> String
|
|
differenceConfigKey ObjectHashLower = tunable "objecthashlower"
|
|
differenceConfigKey OneLevelObjectHash = tunable "objecthash1"
|
|
differenceConfigKey OneLevelBranchHash = tunable "branchhash1"
|
|
|
|
differenceConfigVal :: Difference -> String
|
|
differenceConfigVal _ = Git.Config.boolConfig True
|
|
|
|
tunable :: String -> String
|
|
tunable k = "annex.tune." ++ k
|
|
|
|
hasDifference :: Difference -> Differences -> Bool
|
|
hasDifference d (Differences s) = S.member d s
|
|
hasDifference _ UnknownDifferences = False
|
|
|
|
listDifferences :: Differences -> [Difference]
|
|
listDifferences (Differences s) = S.toList s
|
|
listDifferences UnknownDifferences = []
|