add routes to pause/start/cancel transfers

This commit includes a paydown on technical debt incurred two years ago,
when I didn't know that it was bad to make custom Read and Show instances
for types. As the routes need Read and Show for Transfer, which includes a
Key, and deriving my own Read instance of key was not practical,
I had to finally clean that up.

So the compact Key read and show functions are now file2key and key2file,
and Read and Show are now derived instances.

Changed all code that used the old instances, compiler checked.
(There were a few places, particularly in Command.Unused, and the test
suite where the Show instance continue to be used for legitimate
comparisons; ie show key_x == show key_y (though really in a bloom filter))

Command/AddUnused.hs

@@ -11,6 +11,7 @@ import Common.Annex
 import Logs.Unused
 import Command
 import qualified Command.Add
+import Types.Key
 
 def :: [Command]
 def = [command "addunused" (paramRepeating paramNumRange)
@@ -25,7 +26,7 @@ start = startUnused "addunused" perform (performOther "bad") (performOther "tmp"
 perform :: Key -> CommandPerform
 perform key = next $ Command.Add.cleanup file key True
 	where
-		file = "unused." ++ show key
+		file = "unused." ++ key2file key
 
 {- The content is not in the annex, but in another directory, and
  - it seems better to error out, rather than moving bad/tmp content into

Command/DropKey.hs

@@ -12,6 +12,7 @@ import Command
 import qualified Annex
 import Logs.Location
 import Annex.Content
+import Types.Key
 
 def :: [Command]
 def = [oneShot $ command "dropkey" (paramRepeating paramKey) seek
@@ -24,7 +25,7 @@ start :: Key -> CommandStart
 start key = stopUnless (inAnnex key) $ do
 	unlessM (Annex.getState Annex.force) $
 		error "dropkey can cause data loss; use --force if you're sure you want to do this"
-	showStart "dropkey" (show key)
+	showStart "dropkey" (key2file key)
 	next $ perform key
 
 perform :: Key -> CommandPerform

Command/Find.hs

@@ -53,7 +53,7 @@ start format file (key, _) = do
 	where
 		vars =
 			[ ("file", file)
-			, ("key", show key)
+			, ("key", key2file key)
 			, ("backend", keyBackendName key)
 			, ("bytesize", size show)
 			, ("humansize", size $ roughSize storageUnits True)

Command/FromKey.hs

@@ -22,7 +22,7 @@ seek = [withWords start]
 
 start :: [String] -> CommandStart
 start (keyname:file:[]) = notBareRepo $ do
-	let key = fromMaybe (error "bad key") $ readKey keyname
+	let key = fromMaybe (error "bad key") $ file2key keyname
 	inbackend <- inAnnex key
 	unless inbackend $ error $
 		"key ("++ keyname ++") is not present in backend"

Command/Fsck.hs

@@ -26,6 +26,7 @@ import Utility.DataUnits
 import Utility.FileMode
 import Config
 import qualified Option
+import Types.Key
 
 def :: [Command]
 def = [withOptions options $ command "fsck" paramPaths seek
@@ -114,7 +115,7 @@ startBare :: Key -> CommandStart
 startBare key = case Backend.maybeLookupBackendName (Types.Key.keyBackendName key) of
 	Nothing -> stop
 	Just backend -> do
-		showStart "fsck" (show key)
+		showStart "fsck" (key2file key)
 		next $ performBare key backend
 
 {- Note that numcopies cannot be checked in a bare repository, because
@@ -122,7 +123,7 @@ startBare key = case Backend.maybeLookupBackendName (Types.Key.keyBackendName ke
  - files. -}
 performBare :: Key -> Backend -> CommandPerform
 performBare key backend = check
-	[ verifyLocationLog key (show key)
+	[ verifyLocationLog key (key2file key)
 	, checkKeySize key
 	, checkBackend backend key
 	]

Command/ReKey.hs

@@ -26,7 +26,7 @@ seek = [withPairs start]
 start :: (FilePath, String) -> CommandStart
 start (file, keyname) = ifAnnexed file go stop
 	where
-		newkey = fromMaybe (error "bad key") $ readKey keyname
+		newkey = fromMaybe (error "bad key") $ file2key keyname
 		go (oldkey, _)
 			| oldkey == newkey = stop
 			| otherwise = do

Command/Status.hs

@@ -183,8 +183,8 @@ transfer_list = stat "transfers in progress" $ nojson $ lift $ do
 		pp _ c [] = c
 		pp uuidmap c ((t, i):xs) = "\n\t" ++ line uuidmap t i ++ pp uuidmap c xs
 		line uuidmap t i = unwords
-			[ show (transferDirection t) ++ "ing"
-			, fromMaybe (show $ transferKey t) (associatedFile i)
+			[ showLcDirection (transferDirection t) ++ "ing"
+			, fromMaybe (key2file $ transferKey t) (associatedFile i)
 			, if transferDirection t == Upload then "to" else "from"
 			, maybe (fromUUID $ transferUUID t) Remote.name $
 				M.lookup (transferUUID t) uuidmap

Command/Sync.hs

@@ -25,6 +25,7 @@ import qualified Git
 import Git.Types (BlobType(..))
 import qualified Types.Remote
 import qualified Remote.Git
+import Types.Key
 
 import qualified Data.Map as M
 import qualified Data.ByteString.Lazy as L
@@ -260,8 +261,8 @@ resolveMerge' u
  -}
 mergeFile :: FilePath -> Key -> FilePath
 mergeFile file key
-	| doubleconflict = go $ show key
-	| otherwise = go $ shortHash $ show key
+	| doubleconflict = go $ key2file key
+	| otherwise = go $ shortHash $ key2file key
 	where
 		varmarker = ".variant-"
 		doubleconflict = varmarker `isSuffixOf` (dropExtension file)

Command/Unused.hs

@@ -34,6 +34,7 @@ import qualified Remote
 import qualified Annex.Branch
 import qualified Option
 import Annex.CatFile
+import Types.Key
 
 def :: [Command]
 def = [withOptions [fromOption] $ command "unused" paramNothing seek
@@ -100,7 +101,7 @@ number n (x:xs) = (n+1, x) : number (n+1) xs
 table :: [(Int, Key)] -> [String]
 table l = "  NUMBER  KEY" : map cols l
 	where
-		cols (n,k) = "  " ++ pad 6 (show n) ++ "  " ++ show k
+		cols (n,k) = "  " ++ pad 6 (show n) ++ "  " ++ key2file k
 		pad n s = s ++ replicate (n - length s) ' '
 
 staleTmpMsg :: [(Int, Key)] -> String