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/FilePath.hs

@@ -34,7 +34,7 @@ import qualified System.FilePath.Posix
 import GHC.Generics
 import Control.DeepSeq
 
-{- A FilePath, relative to the top of the git repository. -}
+{- A RawFilePath, relative to the top of the git repository. -}
 newtype TopFilePath = TopFilePath { getTopFilePath :: FilePath }
 	deriving (Show, Eq, Ord, Generic)
 
@@ -46,7 +46,7 @@ data BranchFilePath = BranchFilePath Ref TopFilePath
 
 {- Git uses the branch:file form to refer to a BranchFilePath -}
 descBranchFilePath :: BranchFilePath -> String
-descBranchFilePath (BranchFilePath b f) = fromRef b ++ ':' : getTopFilePath f
+descBranchFilePath (BranchFilePath b f) = fromRef b ++ ':' : (getTopFilePath f)
 
 {- Path to a TopFilePath, within the provided git repo. -}
 fromTopFilePath :: TopFilePath -> Git.Repo -> FilePath
@@ -68,25 +68,25 @@ asTopFilePath file = TopFilePath file
  - despite Windows using '\'.
  -
  -}
-type InternalGitPath = String
+type InternalGitPath = RawFilePath
 
-toInternalGitPath :: FilePath -> InternalGitPath
+toInternalGitPath :: RawFilePath -> InternalGitPath
 #ifndef mingw32_HOST_OS
 toInternalGitPath = id
 #else
-toInternalGitPath = replace "\\" "/"
+toInternalGitPath = encodeBS . replace "\\" "/" . decodeBS
 #endif
 
-fromInternalGitPath :: InternalGitPath -> FilePath
+fromInternalGitPath :: InternalGitPath -> RawFilePath
 #ifndef mingw32_HOST_OS
 fromInternalGitPath = id
 #else
-fromInternalGitPath = replace "/" "\\"
+fromInternalGitPath = encodeBS . replace "/" "\\" . decodeBS
 #endif
 
 {- isAbsolute on Windows does not think "/foo" or "\foo" is absolute,
  - so try posix paths.
  -}
-absoluteGitPath :: FilePath -> Bool
-absoluteGitPath p = isAbsolute p ||
-	System.FilePath.Posix.isAbsolute (toInternalGitPath p)
+absoluteGitPath :: RawFilePath -> Bool
+absoluteGitPath p = isAbsolute (decodeBS p) ||
+	System.FilePath.Posix.isAbsolute (decodeBS (toInternalGitPath p))