replace (Key, Backend) with Key

Only fsck and reinject and the test suite used the Backend, and they can
look it up as needed from the Key. This simplifies the code and also speeds
it up.

There is a small behavior change here. Before, all commands would warn when
acting on an annexed file with an unknown backend. Now, only fsck and
reinject show that warning.

Command/Add.hs

@@ -73,7 +73,7 @@ start file = ifAnnexed file addpresent add
 				| otherwise -> do
 					showStart "add" file
 					next $ perform file
-	addpresent (key, _) = ifM isDirect
+	addpresent key = ifM isDirect
 		( ifM (goodContent key file) ( stop , add )
 		, fixup key
 		)

Command/AddUrl.hs

@@ -96,7 +96,7 @@ performQuvi :: Bool -> URLString -> URLString -> FilePath -> CommandPerform
 performQuvi relaxed pageurl videourl file = ifAnnexed file addurl geturl
   where
   	quviurl = setDownloader pageurl QuviDownloader
-  	addurl (key, _backend) = next $ cleanup quviurl file key Nothing
+  	addurl key = next $ cleanup quviurl file key Nothing
 	geturl = next $ addUrlFileQuvi relaxed quviurl videourl file
 #endif
 
@@ -130,7 +130,7 @@ perform :: Bool -> URLString -> FilePath -> CommandPerform
 perform relaxed url file = ifAnnexed file addurl geturl
   where
 	geturl = next $ addUrlFile relaxed url file
-	addurl (key, _backend)
+	addurl key
 		| relaxed = do
 			setUrlPresent key url
 			next $ return True

Command/Copy.hs

@@ -30,9 +30,9 @@ seek ps = do
 {- A copy is just a move that does not delete the source file.
  - However, --auto mode avoids unnecessary copies, and avoids getting or
  - sending non-preferred content. -}
-start :: Maybe Remote -> Maybe Remote -> FilePath -> (Key, Backend) -> CommandStart
-start to from file (key, backend) = stopUnless shouldCopy $ 
-	Command.Move.start to from False file (key, backend)
+start :: Maybe Remote -> Maybe Remote -> FilePath -> Key -> CommandStart
+start to from file key = stopUnless shouldCopy $ 
+	Command.Move.start to from False file key
   where
 	shouldCopy = checkAuto (check <||> numCopiesCheck file key (<))
 	check = case to of

Command/Direct.hs

@@ -47,7 +47,7 @@ perform = do
 	void $ liftIO clean
 	next cleanup
   where
-	go = whenAnnexed $ \f (k, _) -> do
+	go = whenAnnexed $ \f k -> do
 		r <- toDirectGen k f
 		case r of
 			Nothing -> noop

Command/Drop.hs

@@ -34,8 +34,8 @@ seek ps = do
 	from <- getOptionField dropFromOption Remote.byNameWithUUID
 	withFilesInGit (whenAnnexed $ start from) ps
 
-start :: Maybe Remote -> FilePath -> (Key, Backend) -> CommandStart
-start from file (key, _) = checkDropAuto from file key $ \numcopies ->
+start :: Maybe Remote -> FilePath -> Key -> CommandStart
+start from file key = checkDropAuto from file key $ \numcopies ->
 	stopUnless (checkAuto $ wantDrop False (Remote.uuid <$> from) (Just key) (Just file)) $
 		case from of
 			Nothing -> startLocal (Just file) numcopies key Nothing

Command/Find.hs

@@ -39,8 +39,8 @@ seek ps = do
 	format <- getFormat
 	withFilesInGit (whenAnnexed $ start format) ps
 
-start :: Maybe Utility.Format.Format -> FilePath -> (Key, Backend) -> CommandStart
-start format file (key, _) = do
+start :: Maybe Utility.Format.Format -> FilePath -> Key -> CommandStart
+start format file key = do
 	-- only files inAnnex are shown, unless the user has requested
 	-- others via a limit
 	whenM (limited <||> inAnnex key) $

Command/Fix.hs

@@ -26,8 +26,8 @@ seek :: CommandSeek
 seek = withFilesInGit $ whenAnnexed start
 
 {- Fixes the symlink to an annexed file. -}
-start :: FilePath -> (Key, Backend) -> CommandStart
-start file (key, _) = do
+start :: FilePath -> Key -> CommandStart
+start file key = do
 	link <- inRepo $ gitAnnexLink file key
 	stopUnless ((/=) (Just link) <$> liftIO (catchMaybeIO $ readSymbolicLink file)) $ do
 		showStart "fix" file

Command/Fsck.hs

@@ -104,12 +104,16 @@ getIncremental = do
 						resetStartTime
 		return True
 
-start :: Maybe Remote -> Incremental -> FilePath -> (Key, Backend) -> CommandStart
-start from inc file (key, backend) = do
-	numcopies <- getFileNumCopies file
-	case from of
-		Nothing -> go $ perform key file backend numcopies
-		Just r -> go $ performRemote key file backend numcopies r
+start :: Maybe Remote -> Incremental -> FilePath -> Key -> CommandStart
+start from inc file key = do
+	v <- Backend.getBackend file key
+	case v of
+		Nothing -> stop
+		Just backend -> do
+			numcopies <- getFileNumCopies file
+			case from of
+				Nothing -> go $ perform key file backend numcopies
+				Just r -> go $ performRemote key file backend numcopies r
   where
 	go = runFsck inc file key
 

Command/Get.hs

@@ -31,8 +31,8 @@ seek ps = do
 		(withFilesInGit $ whenAnnexed $ start from)
 		ps
 
-start :: Maybe Remote -> FilePath -> (Key, Backend) -> CommandStart
-start from file (key, _) = start' expensivecheck from key (Just file)
+start :: Maybe Remote -> FilePath -> Key -> CommandStart
+start from file key = start' expensivecheck from key (Just file)
   where
 	expensivecheck = checkAuto (numCopiesCheck file key (<) <||> wantGet False (Just key) (Just file))
 

Command/ImportFeed.hs

@@ -194,7 +194,7 @@ performDownload relaxed cache todownload = case location todownload of
 				in d </> show n ++ "_" ++ base
 		tryanother = makeunique url (n + 1) file
 		alreadyexists = liftIO $ isJust <$> catchMaybeIO (getSymbolicLinkStatus f)
-		checksameurl (k, _) = ifM (elem url <$> getUrls k)
+		checksameurl k = ifM (elem url <$> getUrls k)
 			( return Nothing
 			, tryanother
 			)

Command/Indirect.hs

@@ -74,7 +74,7 @@ perform = do
 		case r of
 			Just s
 				| isSymbolicLink s -> void $ flip whenAnnexed f $
-					\_ (k, _) -> do
+					\_ k -> do
 						removeInodeCache k
 						removeAssociatedFiles k
 						return Nothing

Command/List.hs

@@ -60,8 +60,8 @@ getList = ifM (Annex.getFlag $ optionName allrepos)
 printHeader :: [(UUID, RemoteName, TrustLevel)] -> Annex ()
 printHeader l = liftIO $ putStrLn $ header $ map (\(_, n, t) -> (n, t)) l
 
-start :: [(UUID, RemoteName, TrustLevel)] -> FilePath -> (Key, Backend) -> CommandStart
-start l file (key, _) = do
+start :: [(UUID, RemoteName, TrustLevel)] -> FilePath -> Key -> CommandStart
+start l file key = do
 	ls <- S.fromList <$> keyLocations key
 	liftIO $ putStrLn $ format (map (\(u, _, t) -> (t, S.member u ls)) l) file
 	stop

Command/Log.hs

@@ -64,9 +64,15 @@ seek ps = do
 		Annex.getField (optionName o)
 	use o v = [Param ("--" ++ optionName o), Param v]
 
-start :: M.Map UUID String -> TimeZone -> [CommandParam] -> Bool ->
-	FilePath -> (Key, Backend) -> CommandStart
-start m zone os gource file (key, _) = do
+start
+	:: M.Map UUID String
+	-> TimeZone
+	-> [CommandParam]
+	-> Bool
+	-> FilePath
+	-> Key
+	-> CommandStart
+start m zone os gource file key = do
 	showLog output =<< readLog <$> getLog key os
 	-- getLog produces a zombie; reap it
 	liftIO reapZombies

Command/MetaData.hs

@@ -63,8 +63,8 @@ seek ps = do
 		(withFilesInGit (whenAnnexed $ start now getfield modmeta))
 		ps
 
-start :: POSIXTime -> Maybe MetaField -> [ModMeta] -> FilePath -> (Key, Backend) -> CommandStart
-start now f ms file (k, _) = start' (Just file) now f ms k
+start :: POSIXTime -> Maybe MetaField -> [ModMeta] -> FilePath -> Key -> CommandStart
+start now f ms file = start' (Just file) now f ms
 
 startKeys :: POSIXTime -> Maybe MetaField -> [ModMeta] -> Key -> CommandStart
 startKeys = start' Nothing

Command/Migrate.hs

@@ -25,15 +25,19 @@ def = [notDirect $
 seek :: CommandSeek
 seek = withFilesInGit $ whenAnnexed start
 
-start :: FilePath -> (Key, Backend) -> CommandStart
-start file (key, oldbackend) = do
-	exists <- inAnnex key
-	newbackend <- choosebackend =<< chooseBackend file
-	if (newbackend /= oldbackend || upgradableKey oldbackend key) && exists
-		then do
-			showStart "migrate" file
-			next $ perform file key oldbackend newbackend
-		else stop
+start :: FilePath -> Key -> CommandStart
+start file key = do
+	v <- Backend.getBackend file key
+	case v of
+		Nothing -> stop
+		Just oldbackend -> do
+			exists <- inAnnex key
+			newbackend <- choosebackend =<< chooseBackend file
+			if (newbackend /= oldbackend || upgradableKey oldbackend key) && exists
+				then do
+					showStart "migrate" file
+					next $ perform file key oldbackend newbackend
+				else stop
   where
 	choosebackend Nothing = Prelude.head <$> orderedList
 	choosebackend (Just backend) = return backend

Command/Mirror.hs

@@ -31,8 +31,8 @@ seek ps = do
 		(withFilesInGit $ whenAnnexed $ start to from)
 		ps
 
-start :: Maybe Remote -> Maybe Remote -> FilePath -> (Key, Backend) -> CommandStart
-start to from file (key, _backend) = startKey to from (Just file) key
+start :: Maybe Remote -> Maybe Remote -> FilePath -> Key -> CommandStart
+start to from file key = startKey to from (Just file) key
 
 startKey :: Maybe Remote -> Maybe Remote -> Maybe FilePath -> Key -> CommandStart
 startKey to from afile key = do

Command/Move.hs

@@ -33,8 +33,8 @@ seek ps = do
 		(withFilesInGit $ whenAnnexed $ start to from True)
 		ps
 
-start :: Maybe Remote -> Maybe Remote -> Bool -> FilePath -> (Key, Backend) -> CommandStart
-start to from move file (key, _) = start' to from move (Just file) key
+start :: Maybe Remote -> Maybe Remote -> Bool -> FilePath -> Key -> CommandStart
+start to from move file key = start' to from move (Just file) key
 
 startKey :: Maybe Remote -> Maybe Remote -> Bool -> Key -> CommandStart
 startKey to from move = start' to from move Nothing

Command/ReKey.hs

@@ -29,7 +29,7 @@ start :: (FilePath, String) -> CommandStart
 start (file, keyname) = ifAnnexed file go stop
   where
 	newkey = fromMaybe (error "bad key") $ file2key keyname
-	go (oldkey, _)
+	go oldkey
 		| oldkey == newkey = stop
 		| otherwise = do
 			showStart "rekey" file

Command/Reinject.hs

@@ -12,6 +12,7 @@ import Command
 import Logs.Location
 import Annex.Content
 import qualified Command.Fsck
+import qualified Backend
 
 def :: [Command]
 def = [command "reinject" (paramPair "SRC" "DEST") seek
@@ -33,16 +34,20 @@ start (src:dest:[])
 		next $ whenAnnexed (perform src) dest
 start _ = error "specify a src file and a dest file"
 
-perform :: FilePath -> FilePath -> (Key, Backend) -> CommandPerform
-perform src _dest (key, backend) =
+perform :: FilePath -> FilePath -> Key -> CommandPerform
+perform src dest key = do
 	{- Check the content before accepting it. -}
-	ifM (Command.Fsck.checkKeySizeOr reject key src
-		<&&> Command.Fsck.checkBackendOr reject backend key src)
-		( do
-			unlessM move $ error "mv failed!"
-			next $ cleanup key
-		, error "not reinjecting"
-		)
+	v <- Backend.getBackend dest key
+	case v of
+		Nothing -> stop
+		Just backend ->
+			ifM (Command.Fsck.checkKeySizeOr reject key src
+				<&&> Command.Fsck.checkBackendOr reject backend key src)
+				( do
+					unlessM move $ error "mv failed!"
+					next $ cleanup key
+				, error "not reinjecting"
+				)
   where
 	-- the file might be on a different filesystem,
 	-- so mv is used rather than simply calling

Command/RmUrl.hs

@@ -20,7 +20,7 @@ seek :: CommandSeek
 seek = withPairs start
 
 start :: (FilePath, String) -> CommandStart
-start (file, url) = flip whenAnnexed file $ \_ (key, _) -> do
+start (file, url) = flip whenAnnexed file $ \_ key -> do
 	showStart "rmurl" file
 	next $ next $ cleanup url key
 

Command/Sync.hs

@@ -338,8 +338,8 @@ seekSyncContent rs = do
 		(\v -> void (liftIO (tryPutMVar mvar ())) >> syncFile rs f v)
 		noop
 
-syncFile :: [Remote] -> FilePath -> (Key, Backend) -> Annex ()
-syncFile rs f (k, _) = do
+syncFile :: [Remote] -> FilePath -> Key -> Annex ()
+syncFile rs f k = do
 	locs <- loggedLocations k
 	let (have, lack) = partition (\r -> Remote.uuid r `elem` locs) rs
 

Command/Unannex.hs

@@ -58,8 +58,8 @@ wrapUnannex a = ifM isDirect
 			then void (liftIO cleanup) >> return True
 			else void (liftIO cleanup) >> return False
 
-start :: FilePath -> (Key, Backend) -> CommandStart
-start file (key, _) = stopUnless (inAnnex key) $ do
+start :: FilePath -> Key -> CommandStart
+start file key = stopUnless (inAnnex key) $ do
 	showStart "unannex" file
 	next $ ifM isDirect
 		( performDirect file key

Command/Uninit.hs

@@ -44,7 +44,7 @@ seek ps = do
 
 {- git annex symlinks that are not checked into git could be left by an
  - interrupted add. -}
-startCheckIncomplete :: FilePath -> (Key, Backend) -> CommandStart
+startCheckIncomplete :: FilePath -> Key -> CommandStart
 startCheckIncomplete file _ = error $ unlines
 	[ file ++ " points to annexed content, but is not checked into git."
 	, "Perhaps this was left behind by an interrupted git annex add?"

Command/Unlock.hs

@@ -25,8 +25,8 @@ seek = withFilesInGit $ whenAnnexed start
 
 {- The unlock subcommand replaces the symlink with a copy of the file's
  - content. -}
-start :: FilePath -> (Key, Backend) -> CommandStart
-start file (key, _) = do
+start :: FilePath -> Key -> CommandStart
+start file key = do
 	showStart "unlock" file
 	next $ perform file key
 

Command/Unused.hs

@@ -250,7 +250,7 @@ withKeysReferenced' mdir initial a = do
 		x <- Backend.lookupFile f
 		case x of
 			Nothing -> go v fs
-			Just (k, _) -> do
+			Just k -> do
 				!v' <- a k f v
 				go v' fs
 
@@ -294,7 +294,7 @@ withKeysReferencedInGitRef a ref = do
 	forM_ ts $ tKey lookAtWorkingTree >=> maybe noop a
 	liftIO $ void clean
   where
-	tKey True = fmap fst <$$> Backend.lookupFile . getTopFilePath . DiffTree.file
+	tKey True = Backend.lookupFile . getTopFilePath . DiffTree.file
 	tKey False = fileKey . takeFileName . decodeBS <$$>
 		catFile ref . getTopFilePath . DiffTree.file
 

Command/Whereis.hs

@@ -27,8 +27,8 @@ seek ps = do
 		(withFilesInGit $ whenAnnexed $ start m)
 		ps
 
-start :: M.Map UUID Remote -> FilePath -> (Key, Backend) -> CommandStart
-start remotemap file (key, _) = start' remotemap key (Just file)
+start :: M.Map UUID Remote -> FilePath -> Key -> CommandStart
+start remotemap file key = start' remotemap key (Just file)
 
 startKeys :: M.Map UUID Remote -> Key -> CommandStart
 startKeys remotemap key = start' remotemap key Nothing