fix serveGet hang

This came down to SendBytes waiting on the waitv. Nothing ever filled
it.

Only Annex.Proxy needs the waitv, and it handles filling it. So make it
optional.

Annex/Proxy.hs

@@ -59,8 +59,8 @@ proxySpecialRemoteSide clientmaxversion r = mkRemoteSide r $ do
 	let remoteconn = P2PConnection
 		{ connRepo = Nothing
 		, connCheckAuth = const False
-		, connIhdl = P2PHandleTMVar ihdl iwaitv
-		, connOhdl = P2PHandleTMVar ohdl owaitv
+		, connIhdl = P2PHandleTMVar ihdl (Just iwaitv)
+		, connOhdl = P2PHandleTMVar ohdl (Just owaitv)
 		, connIdent = ConnIdent (Just (Remote.name r))
 		}
 	let closeremoteconn = do

P2P/Annex.hs

@@ -107,23 +107,16 @@ runLocal runst runner a = case a of
 				ProtoFailureMessage "Transfer failed"
 			let consumer' b ti = do
 				validator <- consumer b
-				liftIO $ print "got validator"
 				indicatetransferred ti
-				liftIO $ print "indicatetransferred ti done"
 				return validator
 			runner getb >>= \case
 				Left e -> giveup $ describeProtoFailure e
 				Right b -> checktransfer (\ti -> Right <$> consumer' b ti) fallback >>= \case
 					Left e -> return (Left e)
-					Right validator -> do
-						liftIO $ print "running validity check"
+					Right validator ->
 						runner validitycheck >>= \case
-							Right v -> do
-								liftIO $ print ("calling validator 1", v)
-								Right <$> validator v
-							_ -> do
-								liftIO $ print "calling validator nothing"
-								Right <$> validator Nothing
+							Right v -> Right <$> validator v
+							_ -> Right <$> validator Nothing
 		case v of
 			Left e -> return $ Left $ ProtoFailureException e
 			Right (Left e) -> return $ Left e

P2P/Http.hs

@@ -156,31 +156,24 @@ serveGet st apiver (B64Key k) cu su bypass baf startat sec auth = do
 	endv <- liftIO newEmptyTMVarIO
 	validityv <- liftIO newEmptyTMVarIO
 	aid <- liftIO $ async $ inAnnexWorker st $ do
-		let consumer bs = do
-			liftIO $ atomically $ putTMVar bsv bs
-			liftIO $ print "consumer waiting for endv"
+		let storer _offset len = sendContentWith $ \bs -> do
+			liftIO $ atomically $ putTMVar bsv (len, bs)
 			liftIO $ atomically $ takeTMVar endv
-			liftIO $ print "consumer took endv"
 			return $ \v -> do
-				liftIO $ print "consumer put validityv"
-				liftIO $ atomically $
-					putTMVar validityv v
+				liftIO $ atomically $ putTMVar validityv v
 				return True
-		let storer _offset _len getdata checkvalidity =
-			sendContentWith consumer getdata checkvalidity
 		enteringStage (TransferStage Upload) $
 			runFullProto runst conn $
 				void $ receiveContent Nothing nullMeterUpdate
 					sizer storer getreq
-	bs <- liftIO $ atomically $ takeTMVar bsv
+	(Len len, bs) <- liftIO $ atomically $ takeTMVar bsv
 	bv <- liftIO $ newMVar (L.toChunks bs)
 	let streamer = S.SourceT $ \s -> s =<< return 
 		(stream (releaseconn, bv, endv, validityv, aid))
- 	return $ addHeader 111111 streamer
+ 	return $ addHeader len streamer
   where
 	stream (releaseconn, bv, endv, validityv, aid) =
-		S.fromActionStep B.null $ do
-			print "chunk"
+		S.fromActionStep B.null $
 			modifyMVar bv $ nextchunk $
 				cleanup (releaseconn, endv, validityv, aid)
 	
@@ -194,11 +187,8 @@ serveGet st apiver (B64Key k) cu su bypass baf startat sec auth = do
 	cleanup (releaseconn, endv, validityv, aid) =
 		ifM (atomically $ isEmptyTMVar endv)
 			( do
-				print "at end"
 				atomically $ putTMVar endv ()
-				print "signaled end"
 				validity <- atomically $ takeTMVar validityv
-				print ("got validity", validity)
 				wait aid >>= \case
 					Left ex -> throwM ex
 					Right (Left err) -> error $
@@ -263,6 +253,7 @@ gatherbytestring x = do
 	go (S.Effect ms) = do
 		ms >>= go
 	go (S.Yield v s) = do
+		liftIO $ print ("chunk", B.length v)
 		LI.Chunk v <$> unsafeInterleaveIO (go s)
 
 clientGet'

P2P/Http/State.hs

@@ -177,35 +177,38 @@ withLocalP2PConnections a = do
 			else do
 				hdl1 <- liftIO newEmptyTMVarIO
 				hdl2 <- liftIO newEmptyTMVarIO
-				waitv1 <- liftIO newEmptyTMVarIO
-				waitv2 <- liftIO newEmptyTMVarIO
-				let h1 = P2PHandleTMVar hdl1 waitv1
-				let h2 = P2PHandleTMVar hdl2 waitv2 
+				let h1 = P2PHandleTMVar hdl1 Nothing
+				let h2 = P2PHandleTMVar hdl2 Nothing
 				let serverconn = P2PConnection Nothing
 					(const True) h1 h2
 					(ConnIdent (Just "http server"))
 				let clientconn = P2PConnection Nothing
 					(const True) h2 h1
 					(ConnIdent (Just "http client"))
-				runst <- liftIO $ mkrunst connparams
+				clientrunst <- liftIO $ mkclientrunst connparams
+				serverrunst <- liftIO $ mkserverrunst connparams
 				let server = P2P.serveOneCommandAuthed
 					(connectionServerMode connparams)
 					(connectionServerUUID connparams)
 				let protorunner = void $
-					runFullProto runst serverconn server
+					runFullProto serverrunst serverconn server
 				asyncworker <- liftIO . async 
 					=<< forkState protorunner
 				let releaseconn = atomically $ putTMVar relv $
 					join (liftIO (wait asyncworker))
-				return $ Right (runst, clientconn, releaseconn)
+				return $ Right (clientrunst, clientconn, releaseconn)
 		liftIO $ atomically $ putTMVar respvar resp
 
-	mkrunst connparams = do
+	mkserverrunst connparams = do
 		prototvar <- newTVarIO $ connectionProtocolVersion connparams
 		mkRunState $ const $ Serving 
 			(connectionClientUUID connparams)
 			Nothing
 			prototvar
+	
+	mkclientrunst connparams = do
+		prototvar <- newTVarIO $ connectionProtocolVersion connparams
+		mkRunState $ const $ Client prototvar
 
 data Locker = Locker
 	{ lockerThread :: Async ()

P2P/IO.hs

@@ -79,7 +79,7 @@ mkRunState mk = do
 
 data P2PHandle
 	= P2PHandle Handle
-	| P2PHandleTMVar (TMVar (Either L.ByteString Message)) (TMVar ())
+	| P2PHandleTMVar (TMVar (Either L.ByteString Message)) (Maybe (TMVar ()))
 
 data P2PConnection = P2PConnection
 	{ connRepo :: Maybe Repo
@@ -217,7 +217,7 @@ runNet runst conn runner f = case f of
 			Right () -> runner next
 	ReceiveMessage next ->
 		let protoerr = return $ Left $
-			ProtoFailureMessage "protocol error 1"
+			ProtoFailureMessage "protocol error"
 		    gotmessage m = do
 			liftIO $ debugMessage conn "P2P <" m
 			runner (next (Just m))
@@ -246,11 +246,14 @@ runNet runst conn runner f = case f of
 					Right False -> return $ Left $
 						ProtoFailureMessage "short data write"
 					Left e -> return $ Left $ ProtoFailureException e
-			P2PHandleTMVar mv waitv -> do
+			P2PHandleTMVar mv mwaitv -> do
 				liftIO $ atomically $ putTMVar mv (Left b)
-				-- Wait for the whole bytestring to be
-				-- processed. Necessary due to lazyiness.
-				liftIO $ atomically $ takeTMVar waitv
+				case mwaitv of
+					-- Wait for the whole bytestring to
+					-- be processed.
+					Just waitv -> liftIO $ atomically $
+						takeTMVar waitv
+					Nothing -> return ()
 				runner next
 	ReceiveBytes len p next ->
 		case connIhdl conn of
@@ -264,7 +267,7 @@ runNet runst conn runner f = case f of
 				liftIO (atomically (takeTMVar mv)) >>= \case
 					Left b -> runner (next b)
 					Right _ -> return $ Left $
-						ProtoFailureMessage "protocol error 2"
+						ProtoFailureMessage "protocol error"
 	CheckAuthToken _u t next -> do
 		let authed = connCheckAuth conn t
 		runner (next authed)

doc/todo/git-annex_proxies.mdwn

@@ -31,8 +31,7 @@ Planned schedule of work:
 * http server and client are working, remaining 
   server API endpoints need wiring up and testing. 
 
-* serveGet works as proof of concept, but is very buggy.
-  See commit 1e0f92a5a1ccf7ff4c51c67c27a826709a99301b
+* serveGet needs to handle invalidation
 
 * I have a file `servant.hs` in the httpproto branch that works through some
   of the bytestring streaming issues.