factor out Annex.GitShaKey

Annex/Export.hs

@@ -11,16 +11,13 @@ module Annex.Export where
 
 import Annex
 import Annex.CatFile
+import Annex.GitShaKey
 import Types
-import Types.Key
 import qualified Git
 import qualified Types.Remote as Remote
 import Git.Quote
 import Messages
 
-import Data.Maybe
-import qualified Data.ByteString.Short as S (fromShort, toShort)
-
 -- From a sha pointing to the content of a file to the key
 -- to use to export it. When the file is annexed, it's the annexed key.
 -- When the file is stored in git, it's a special type of key to indicate
@@ -31,31 +28,6 @@ exportKey sha = mk <$> catKey sha
 	mk (Just k) = k
 	mk Nothing = gitShaKey sha
 
--- Encodes a git sha as a key. This is used to represent a non-annexed
--- file that is stored on a special remote, which necessarily needs a
--- key.
---
--- This is not the same as a SHA1 key, because the mapping needs to be
--- bijective, also because git may not always use SHA1, and because git
--- takes a SHA1 of the file size + content, while git-annex SHA1 keys
--- only checksum the content.
-gitShaKey :: Git.Sha -> Key
-gitShaKey (Git.Ref s) = mkKey $ \kd -> kd
-	{ keyName = S.toShort s
-	, keyVariety = OtherKey "GIT"
-	}
-
--- Reverse of gitShaKey
-keyGitSha :: Key -> Maybe Git.Sha
-keyGitSha k
-	| fromKey keyVariety k == OtherKey "GIT" =
-		Just (Git.Ref (S.fromShort (fromKey keyName k)))
-	| otherwise = Nothing
-
--- Is a key storing a git sha, and not used for an annexed file?
-isGitShaKey :: Key -> Bool
-isGitShaKey = isJust . keyGitSha
-
 warnExportImportConflict :: Remote -> Annex ()
 warnExportImportConflict r = do
 	isimport <- Remote.isImportSupported r