wip RawFilePath

Goal is to make git-annex faster by using ByteString for all the
worktree traversal. For now, this is focusing on Command.Find,
in order to benchmark how much it helps. (All other commands are
temporarily disabled)

Currently in a very bad unbuildable in-between state.

Git/Filename.hs

@@ -12,23 +12,29 @@ import Common
 import Utility.Format (decode_c, encode_c)
 
 import Data.Char
+import Data.Word
+import qualified Data.ByteString as S
 
-decode :: String -> FilePath
-decode [] = []
-decode f@(c:s)
-	-- encoded strings will be inside double quotes
-	| c == '"' && end s == ['"'] = decode_c $ beginning s
-	| otherwise = f
+-- encoded filenames will be inside double quotes
+decode :: S.ByteString -> RawFilePath
+decode b = case S.uncons b of
+	Nothing -> b
+	Just (h, t)
+		| h /= q -> b
+		| otherwise -> case S.unsnoc t of
+			Nothing -> b
+			Just (i, l)
+				| l /= q -> b
+				| otherwise ->
+					encodeBS $ decode_c $ decodeBS i
+  where
+  	q :: Word8
+	q = fromIntegral (ord '"')
 
 {- Should not need to use this, except for testing decode. -}
-encode :: FilePath -> String
-encode s = "\"" ++ encode_c s ++ "\""
+encode :: RawFilePath -> S.ByteString
+encode s = encodeBS $ "\"" ++ encode_c (decodeBS s) ++ "\""
 
-{- For quickcheck. 
- -
- - See comment on Utility.Format.prop_encode_c_decode_c_roundtrip for
- - why this only tests chars < 256 -}
-prop_encode_decode_roundtrip :: String -> Bool
-prop_encode_decode_roundtrip s = s' == decode (encode s')
-  where
-	s' = filter (\c -> ord c < 256) s
+{- For quickcheck. -}
+prop_encode_decode_roundtrip :: RawFilePath -> Bool
+prop_encode_decode_roundtrip s = s == decode (encode s)