git-annex/Types/Backend.hs
Joey Hess 4ecba916a1
annex.maxextensionlength
Added annex.maxextensionlength for use cases where extensions longer than 4
characters are needed.

This commit was sponsored by Henrik Riomar on Patreon.
2018-09-24 12:10:18 -04:00

34 lines
1 KiB
Haskell

{- git-annex key backend data type
-
- Most things should not need this, using Types instead
-
- Copyright 2010-2017 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Types.Backend where
import Types.Key
import Types.KeySource
data BackendA a = Backend
{ backendVariety :: KeyVariety
, getKey :: KeySource -> a (Maybe Key)
-- Verifies the content of a key.
, verifyKeyContent :: Maybe (Key -> FilePath -> a Bool)
-- Checks if a key can be upgraded to a better form.
, canUpgradeKey :: Maybe (Key -> Bool)
-- Checks if there is a fast way to migrate a key to a different
-- backend (ie, without re-hashing).
, fastMigrate :: Maybe (Key -> BackendA a -> AssociatedFile -> a (Maybe Key))
-- Checks if a key is known (or assumed) to always refer to the
-- same data.
, isStableKey :: Key -> Bool
}
instance Show (BackendA a) where
show backend = "Backend { name =\"" ++ formatKeyVariety (backendVariety backend) ++ "\" }"
instance Eq (BackendA a) where
a == b = backendVariety a == backendVariety b