git-annex/Types/Backend.hs
Joey Hess 40ecf58d4b
update licenses from GPL to AGPL
This does not change the overall license of the git-annex program, which
was already AGPL due to a number of sources files being AGPL already.

Legally speaking, I'm adding a new license under which these files are
now available; I already released their current contents under the GPL
license. Now they're dual licensed GPL and AGPL. However, I intend
for all my future changes to these files to only be released under the
AGPL license, and I won't be tracking the dual licensing status, so I'm
simply changing the license statement to say it's AGPL.

(In some cases, others wrote parts of the code of a file and released it
under the GPL; but in all cases I have contributed a significant portion
of the code in each file and it's that code that is getting the AGPL
license; the GPL license of other contributors allows combining with
AGPL code.)
2019-03-13 15:48:14 -04:00

36 lines
1.1 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 AGPL version 3 or higher.
-}
module Types.Backend where
import Types.Key
import Types.KeySource
import Utility.FileSystemEncoding
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 =\"" ++ decodeBS (formatKeyVariety (backendVariety backend)) ++ "\" }"
instance Eq (BackendA a) where
a == b = backendVariety a == backendVariety b