more p2p progress meters

Display progress meter on send and receive from remote.

Added a new hGetMetered that can read an exact number of bytes (or
less), updating a meter as it goes.

This commit was sponsored by Andreas on Patreon.

P2P/IO.hs

@@ -119,8 +119,8 @@ runNet conn runner f = case f of
 		case v of
 			Right True -> runner next
 			_ -> return Nothing
-	ReceiveBytes (Len n) next -> do
-		v <- liftIO $ tryNonAsync $ L.hGet (connIhdl conn) (fromIntegral n)
+	ReceiveBytes len p next -> do
+		v <- liftIO $ tryNonAsync $ receiveExactly len (connIhdl conn) p
 		case v of
 			Left _e -> return Nothing
 			Right b -> runner (next b)
@@ -155,9 +155,12 @@ runNet conn runner f = case f of
 -- If too few bytes are sent, the only option is to give up on this
 -- connection. False is returned to indicate this problem.
 sendExactly :: Len -> L.ByteString -> Handle -> MeterUpdate -> IO Bool
-sendExactly (Len l) b h p = do
-	sent <- meteredWrite' p h (L.take (fromIntegral l) b)
-	return (fromBytesProcessed sent == l)
+sendExactly (Len n) b h p = do
+	sent <- meteredWrite' p h (L.take (fromIntegral n) b)
+	return (fromBytesProcessed sent == n)
+
+receiveExactly :: Len -> Handle -> MeterUpdate -> IO L.ByteString
+receiveExactly (Len n) h p = hGetMetered h (Just n) p
 
 runRelay :: RunProto IO -> RelayHandle -> RelayHandle -> IO (Maybe ExitCode)
 runRelay runner (RelayHandle hout) (RelayHandle hin) = bracket setup cleanup go

P2P/Protocol.hs

@@ -167,7 +167,7 @@ data NetF c
 	| SendBytes Len L.ByteString MeterUpdate c
 	-- ^ Sends exactly Len bytes of data. (Any more or less will
 	-- confuse the receiver.)
-	| ReceiveBytes Len (L.ByteString -> c)
+	| ReceiveBytes Len MeterUpdate (L.ByteString -> c)
 	-- ^ Lazily reads bytes from peer. Stops once Len are read,
 	-- or if connection is lost, and in either case returns the bytes
 	-- that were read. This allows resuming interrupted transfers.
@@ -273,8 +273,8 @@ remove key = do
 	net $ sendMessage (REMOVE key)
 	checkSuccess
 
-get :: FilePath -> Key -> AssociatedFile -> Proto Bool
-get dest key af = receiveContent sizer storer (\offset -> GET offset af key)
+get :: FilePath -> Key -> AssociatedFile -> MeterUpdate -> Proto Bool
+get dest key af p = receiveContent p sizer storer (\offset -> GET offset af key)
   where
 	sizer = fileSize dest
 	storer = storeContentTo dest
@@ -364,7 +364,7 @@ serveAuthed myuuid = void $ serverLoop handler
 			else do
 				let sizer = tmpContentSize key
 				let storer = storeContent key af
-				ok <- receiveContent sizer storer PUT_FROM
+				ok <- receiveContent nullMeterUpdate sizer storer PUT_FROM
 				when ok $
 					local $ setPresent key myuuid
 		return ServerContinue
@@ -385,8 +385,8 @@ sendContent key af offset p = do
 	net $ sendBytes len content p
 	checkSuccess
 
-receiveContent :: Local Len -> (Offset -> Len -> L.ByteString -> Local Bool) -> (Offset -> Message) -> Proto Bool
-receiveContent sizer storer mkmsg = do
+receiveContent :: MeterUpdate -> Local Len -> (Offset -> Len -> L.ByteString -> Local Bool) -> (Offset -> Message) -> Proto Bool
+receiveContent p sizer storer mkmsg = do
 	Len n <- local sizer
 	let offset = Offset n
 	net $ sendMessage (mkmsg offset)
@@ -394,7 +394,7 @@ receiveContent sizer storer mkmsg = do
 	case r of
 		DATA len -> do
 			ok <- local . storer offset len
-				=<< net (receiveBytes len)
+				=<< net (receiveBytes len p)
 			sendSuccess ok
 			return ok
 		_ -> do
@@ -447,7 +447,7 @@ relayFromPeer = do
 	r <- receiveMessage
 	case r of
 		CONNECTDONE exitcode -> return $ RelayDone exitcode
-		DATA len -> RelayFromPeer <$> receiveBytes len
+		DATA len -> RelayFromPeer <$> receiveBytes len nullMeterUpdate
 		_ -> do
 			sendMessage $ ERROR "expected DATA or CONNECTDONE"
 			return $ RelayDone $ ExitFailure 1