git-annex/Backend/WORM.hs

43 lines
1 KiB
Haskell

{- git-annex "WORM" backend -- Write Once, Read Many
-
- Copyright 2010 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Backend.WORM (backends) where
import Control.Monad.State
import System.FilePath
import System.Posix.Files
import qualified Backend.File
import Types.Backend
import Types
import Types.Key
backends :: [Backend Annex]
backends = [backend]
backend :: Backend Annex
backend = Backend.File.backend {
name = "WORM",
getKey = keyValue
}
{- The key includes the file size, modification time, and the
- basename of the filename.
-
- That allows multiple files with the same names to have different keys,
- while also allowing a file to be moved around while retaining the
- same key.
-}
keyValue :: FilePath -> Annex (Maybe Key)
keyValue file = do
stat <- liftIO $ getFileStatus file
return $ Just $ Key {
keyName = takeFileName file,
keyBackendName = name backend,
keySize = Just $ fromIntegral $ fileSize stat,
keyMtime = Just $ modificationTime stat
}