git-annex/Types/Backend.hs
2012-06-05 19:51:03 -04:00

34 lines
912 B
Haskell

{- git-annex key/value backend data type
-
- Most things should not need this, using Types instead
-
- Copyright 2010,2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Types.Backend where
import Types.Key
{- The source used to generate a key. The location of the content
- may be different from the filename associated with the key. -}
data KeySource = KeySource
{ keyFilename :: FilePath
, contentLocation :: FilePath
}
data BackendA a = Backend {
-- name of this backend
name :: String,
-- gets the key to use for a given content
getKey :: KeySource -> a (Maybe Key),
-- called during fsck to check a key, if the backend has its own checks
fsckKey :: Maybe (Key -> FilePath -> a Bool)
}
instance Show (BackendA a) where
show backend = "Backend { name =\"" ++ name backend ++ "\" }"
instance Eq (BackendA a) where
a == b = name a == name b