git-annex/Backend/WORM.hs
Joey Hess 3334d3831b
change retrieveExport and getKey to throw exception
retrieveExport is part of ongoing transition to make remote methods
throw exceptions, rather than silently hide them.

getKey very rarely fails, and when it does it's always for the same reason
(user configured annex.backend to url for some reason). So, this will
avoid dealing with Nothing everywhere it's used.

This commit was sponsored by Ilya Shlyakhter on Patreon.
2020-05-15 13:45:53 -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 = Just 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 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 $ 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