git-annex/Backend/WORM.hs
2020-02-21 10:04:44 -04:00

63 lines
1.8 KiB
Haskell

{- git-annex "WORM" backend -- Write Once, Read Many
-
- Copyright 2010 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Backend.WORM (backends) where
import Annex.Common
import Types.Key
import Types.Backend
import Types.KeySource
import Backend.Utilities
import Git.FilePath
import Utility.Metered
import qualified Data.ByteString.Char8 as S8
import qualified Utility.RawFilePath as R
backends :: [Backend]
backends = [backend]
backend :: Backend
backend = Backend
{ backendVariety = WORMKey
, getKey = keyValue
, verifyKeyContent = Nothing
, canUpgradeKey = Just needsUpgrade
, fastMigrate = Just removeSpaces
, isStableKey = const True
}
{- The key includes the file size, modification time, and the
- original filename relative to the top of the git repository.
-}
keyValue :: KeySource -> MeterUpdate -> Annex (Maybe Key)
keyValue source _ = do
let f = contentLocation source
stat <- liftIO $ R.getFileStatus f
sz <- liftIO $ getFileSize' (fromRawFilePath f) stat
relf <- fromRawFilePath . getTopFilePath
<$> inRepo (toTopFilePath $ keyFilename source)
return $ Just $ mkKey $ \k -> k
{ keyName = genKeyName relf
, keyVariety = WORMKey
, keySize = Just sz
, keyMtime = Just $ modificationTime stat
}
{- Old WORM keys could contain spaces, and can be upgraded to remove them. -}
needsUpgrade :: Key -> Bool
needsUpgrade key = ' ' `S8.elem` fromKey keyName key
removeSpaces :: Key -> Backend -> AssociatedFile -> Annex (Maybe Key)
removeSpaces oldkey newbackend _
| migratable = return $ Just $ alterKey oldkey $ \d -> d
{ keyName = encodeBS $ reSanitizeKeyName $ decodeBS $ keyName d }
| otherwise = return Nothing
where
migratable = oldvariety == newvariety
oldvariety = fromKey keyVariety oldkey
newvariety = backendVariety newbackend