assistant: When there are multiple remotes giving different ways to access the same repository, honor remote cost settings and use the cheapest available.

Note that TransferInfo does not always contain the Remote, although
any transfer added to the TransferQueue does have a Remote in its
TransferInfo. The transferkeys command still accepts a UUID, which is
useful to handle upgrades, where an old assistant version runs the new
transferkeys.

This commit was sponsored by Kalle Svensson.

Command/TransferKeys.hs

@@ -17,6 +17,7 @@ import Annex.Transfer
 import qualified Remote
 import Types.Key
 import Utility.SimpleProtocol (ioHandles)
+import Git.Types (RemoteName)
 
 data TransferRequest = TransferRequest Direction Remote Key AssociatedFile
 
@@ -56,13 +57,13 @@ runRequests readh writeh a = do
 		fileEncoding writeh
 	go =<< readrequests
   where
-  	go (d:u:k:f:rest) = do
-		case (deserialize d, deserialize u, deserialize k, deserialize f) of
-			(Just direction, Just uuid, Just key, Just file) -> do
-				mremote <- Remote.remoteFromUUID uuid
+  	go (d:rn:k:f:rest) = do
+		case (deserialize d, deserialize rn, deserialize k, deserialize f) of
+			(Just direction, Just remotename, Just key, Just file) -> do
+				mremote <- Remote.byName' remotename
 				case mremote of
-					Nothing -> sendresult False
-					Just remote -> sendresult =<< a
+					Left _ -> sendresult False
+					Right remote -> sendresult =<< a
 						(TransferRequest direction remote key file)
 			_ -> sendresult False
 		go rest
@@ -75,13 +76,15 @@ runRequests readh writeh a = do
 		hPutStrLn writeh $ serialize b
 		hFlush writeh
 
-sendRequest :: Transfer -> AssociatedFile -> Handle -> IO ()
-sendRequest t f h = do
+sendRequest :: Transfer -> TransferInfo -> Handle -> IO ()
+sendRequest t info h = do
 	hPutStr h $ intercalate fieldSep
 		[ serialize (transferDirection t)
-		, serialize (transferUUID t)
+		, maybe (serialize (fromUUID (transferUUID t)))
+			(serialize . Remote.name)
+			(transferRemote info)
 		, serialize (transferKey t)
-		, serialize f
+		, serialize (associatedFile info)
 		, "" -- adds a trailing null
 		]
 	hFlush h
@@ -116,9 +119,9 @@ instance TCSerialized AssociatedFile where
 	deserialize "" = Just Nothing
 	deserialize f = Just $ Just f
 
-instance TCSerialized UUID where
-	serialize = fromUUID
-	deserialize = Just . toUUID
+instance TCSerialized RemoteName where
+	serialize n = n
+	deserialize n = Just n
 
 instance TCSerialized Key where
 	serialize = key2file