@@ -1,17 +1,20 @@
1−{-# LANGUAGE DerivingVia, DeriveGeneric, RankNTypes, ScopedTypeVariables, MultiParamTypeClasses, OverloadedStrings, GeneralizedNewtypeDeriving #-}
1+{-# LANGUAGE DerivingVia, DeriveGeneric, RankNTypes, ScopedTypeVariables, MultiParamTypeClasses, OverloadedStrings, GeneralizedNewtypeDeriving, CPP, ExistentialQuantification, StandaloneDeriving, GADTs, RecordWildCards #-}
2+{-# OPTIONS_GHC -fno-warn-orphans #-}
23{- HLINT ignore "Use lambda-case" -}
34module Network.RPC.Curryer.Server where
4−import Streamly
55import qualified Streamly.Prelude as S
66import Streamly.Network.Socket
7−import Streamly.Internal.Network.Socket (handleWithM, writeChunk)
7+import Streamly.Internal.Network.Socket (handleWithM)
88import Network.Socket as Socket
9−import Streamly.Internal.Data.Parser.ParserD as PD
9+import Network.Socket.ByteString as Socket
10+import Streamly.Internal.Data.Parser as P hiding (concatMap)
1011import Codec.Winery
1112import Codec.Winery.Internal (varInt, decodeVarInt, getBytes)
1213import Codec.Winery.Class (mkExtractor)
1314import GHC.Generics
14−import Control.Concurrent.MVar (MVar)
15+import GHC.Fingerprint
16+import Data.Typeable
17+import Control.Concurrent.MVar (MVar, newMVar, withMVar)
1518import Control.Exception
1619import Data.Function ((&))
1720import Data.Word
@@ -20,53 +23,103 @@ import qualified Data.ByteString.Lazy as BSL
2023import qualified Data.ByteString.FastBuilder as BB
2124import Streamly.Data.Fold as FL
2225import qualified Streamly.Internal.Data.Stream.IsStream as S
23−import Data.Foldable
24−import Data.Bits
2526import qualified Data.Binary as B
2627import qualified Data.UUID as UUIDBase
2728import qualified Data.UUID.V4 as UUIDBase
28−import qualified Streamly.Internal.Data.Array.Storable.Foreign.Types as SA
29−import qualified Network.RPC.Curryer.StreamlyAdditions as SA
3029import Control.Monad
30+import Data.Functor
31+
32+import qualified Network.RPC.Curryer.StreamlyAdditions as SA
33+--import Control.Monad
3134import Data.Hashable
35+import System.Timeout
36+import qualified Network.ByteOrder as BO
37+
3238
3339-- for toArrayS conversion
3440import qualified Data.ByteString.Internal as BSI
35−import Foreign.ForeignPtr (plusForeignPtr)
41+import qualified Streamly.Internal.Data.Array.Storable.Foreign.Types as Arr
3642import Foreign.ForeignPtr.Unsafe (unsafeForeignPtrToPtr)
37−import GHC.Ptr (plusPtr)
43+import GHC.Ptr (minusPtr)
3844
45+-- define CURRYER_SHOW_BYTES 1
46+#if CURRYER_SHOW_BYTES == 1
3947import Debug.Trace
48+#endif
49+
50+traceBytes :: Applicative f => String -> BS.ByteString -> f ()
51+#if CURRYER_SHOW_BYTES == 1
52+traceBytes msg bs = traceShowM (msg, BS.length bs, bs)
53+#else
54+traceBytes _ _ = pure ()
55+#endif
56+
57+data Locking a = Locking (MVar ()) a
58+
59+newLock :: a -> IO (Locking a)
60+newLock x = do
61+ lock <- newMVar ()
62+ pure (Locking lock x)
63+
64+withLock :: Locking a -> (a -> IO b) -> IO b
65+withLock (Locking mvar v) m =
66+ withMVar mvar $ \_ -> m v
67+
68+lockless :: Locking a -> a
69+lockless (Locking _ a) = a
70+
71+type Timeout = Word32
4072
41−data ClientHelloMessage = ClientHelloMessage Int Int
42− deriving Generic
43− deriving Serialise via WineryVariant ClientHelloMessage
44−
45−data ServerHelloMessage = ServerHelloMessage { serverServices :: [String],
46− serverInfo :: String
47− }
48− deriving Generic
49− deriving Serialise via WineryRecord ServerHelloMessage
50−
51−--request-response token
52−--client-side timeout
53−--server-to-client and client-to-server async request (no response requested)
54−
55−data Message a = Response UUID a
56− | AsyncRequest UUID a
57− | ResponseExpectedRequest UUID a
58− -- | Services
59− | ExceptionResponse String
60− deriving (Generic, Show)
61− deriving Serialise via WineryVariant (Message a)
62−
63−-- | The response type
64−data HandlerResponse a = NoResponse
65− | HandlerResponse a
66− | HandlerException a
67− deriving Generic
68− deriving Serialise via WineryVariant (HandlerResponse a)
73+type BinaryMessage = BS.ByteString
6974
75+--includes the fingerprint of the incoming data type (held in the BinaryMessage) to determine how to dispatch the message.
76+--add another envelope type for unencoded binary messages for any easy optimization for in-process communication
77+data Envelope = Envelope {
78+ envFingerprint :: !Fingerprint,
79+ envMessageType :: !MessageType,
80+ envMsgId :: !UUID,
81+ envPayload :: !BinaryMessage
82+ }
83+ deriving (Generic, Show)
84+
85+type TimeoutMicroseconds = Int
86+
87+deriving instance Generic Fingerprint
88+deriving via WineryVariant Fingerprint instance Serialise Fingerprint
89+
90+-- | Internal type used to mark envelope types.
91+data MessageType = RequestMessage TimeoutMicroseconds
92+ | ResponseMessage
93+ | TimeoutResponseMessage
94+ | ExceptionResponseMessage
95+ deriving (Generic, Show)
96+ deriving Serialise via WineryVariant MessageType
97+
98+-- | A list of `RequestHandler`s.
99+type RequestHandlers serverState = [RequestHandler serverState]
100+
101+-- | Data types for server-side request handlers, in synchronous (client waits for return value) and asynchronous (client does not wait for return value) forms.
102+data RequestHandler serverState where
103+ -- | create a request handler with a response
104+ RequestHandler :: forall a b serverState. (Serialise a, Serialise b) => (ConnectionState serverState -> a -> IO b) -> RequestHandler serverState
105+ -- | create an asynchronous request handler where the client does not expect nor await a response
106+ AsyncRequestHandler :: forall a serverState. Serialise a => (ConnectionState serverState -> a -> IO ()) -> RequestHandler serverState
107+
108+-- | Server state sent in via `serve` and passed to `RequestHandler`s.
109+data ConnectionState a = ConnectionState {
110+ connectionServerState :: a,
111+ connectionSocket :: Locking Socket
112+ }
113+
114+-- | Used by server-side request handlers to send additional messages to the client. This is useful for sending asynchronous responses to the client outside of the normal request-response flow. The locking socket can be found in the ConnectionState when a request handler is called.
115+sendMessage :: Serialise a => Locking Socket -> a -> IO ()
116+sendMessage lockSock msg = do
117+ requestID <- UUID <$> UUIDBase.nextRandom
118+ let env =
119+ Envelope (fingerprint msg) (RequestMessage timeout') requestID (serialise msg)
120+ timeout' = 0
121+ sendEnvelope env lockSock
122+
70123--avoid orphan instance
71124newtype UUID = UUID { _unUUID :: UUIDBase.UUID }
72125 deriving (Show, Eq, B.Binary, Hashable)
@@ -85,12 +138,18 @@ instance Serialise UUID where
85138 x -> error $ "invalid schema element " <> show x
86139 decodeCurrent = B.decode . BSL.fromStrict <$> (decodeVarInt >>= getBytes)
87140
88−
141+-- | Errors from remote calls.
89142data ConnectionError = CodecError String -- show of WineryException from exception initiator which cannot otherwise be transmitted over a line due to dependencies on TypeReps
90143 | TimeoutError
144+ | ExceptionError String
91145 deriving (Generic, Show, Eq)
92146 deriving Serialise via WineryVariant ConnectionError
93147
148+data TimeoutException = TimeoutException
149+ deriving Show
150+
151+instance Exception TimeoutException
152+
94153type HostAddr = (Word8, Word8, Word8, Word8)
95154
96155allHostAddrs,localHostAddr :: HostAddr
@@ -98,111 +157,186 @@ allHostAddrs = (0,0,0,0)
98157localHostAddr = (127,0,0,1)
99158
100159-- Each message is length-prefixed by a 32-bit unsigned length.
101−messageBoundaryP :: Parser IO Word8 BS.ByteString
102−messageBoundaryP = do
103− --traceShowM "message!"
104− w4x8 <- PD.take 4 FL.toList
105− --traceShowM ("w4x8",w4x8)
106− let c = fromIntegral (fromOctets w4x8)
107− --traceShowM ("c", c)
108− vals <- PD.take c FL.toList
109− let bytes = BS.pack vals
110− traceShowM ("vals", BS.length bytes, bytes)
111− pure bytes
160+envelopeP :: Parser IO Word8 Envelope
161+envelopeP = do
162+ let msgTypeP = (P.satisfy (== 0) *>
163+ (RequestMessage . fromIntegral <$> word32P)) `P.alt`
164+ (P.satisfy (== 1) $> ResponseMessage) `P.alt`
165+ (P.satisfy (== 2) $> TimeoutResponseMessage) `P.alt`
166+ (P.satisfy (== 3) $> ExceptionResponseMessage)
167+ lenPrefixedByteStringP = do
168+ c <- fromIntegral <$> word32P
169+ --streamly can't handle takeEQ 0, so add special handling
170+ if c == 0 then
171+ pure BS.empty
172+ else
173+ fromArray <$> P.takeEQ c (Arr.writeN c)
174+ Envelope <$> fingerprintP <*> msgTypeP <*> uuidP <*> lenPrefixedByteStringP
175+
176+encodeEnvelope :: Envelope -> BS.ByteString
177+encodeEnvelope (Envelope (Fingerprint fp1 fp2) msgType msgId bs) =
178+ fingerprintBs <> msgTypeBs <> msgIdBs <> lenPrefixedBs
179+ where
180+ fingerprintBs = BO.bytestring64 fp1 <> BO.bytestring64 fp2
181+ msgTypeBs = case msgType of
182+ RequestMessage timeoutms -> BS.singleton 0 <> BO.bytestring32 (fromIntegral timeoutms)
183+ ResponseMessage -> BS.singleton 1
184+ TimeoutResponseMessage -> BS.singleton 2
185+ ExceptionResponseMessage -> BS.singleton 3
186+ msgIdBs =
187+ case UUIDBase.toWords (_unUUID msgId) of
188+ (u1, u2, u3, u4) -> foldr ((<>) . BO.bytestring32) BS.empty [u1, u2, u3, u4]
189+ msgLen = fromIntegral (BS.length bs)
190+ lenPrefixedBs = BO.bytestring32 msgLen <> bs
191+
192+fingerprintP :: Parser IO Word8 Fingerprint
193+fingerprintP =
194+ Fingerprint <$> word64P <*> word64P
195+
196+word64P :: Parser IO Word8 Word64
197+word64P = do
198+ let s = FL.toList
199+ b <- P.takeEQ 8 s
200+ pure (BO.word64 (BS.pack b))
201+
202+--parse a 32-bit integer from network byte order
203+word32P :: Parser IO Word8 Word32
204+word32P = do
205+ let s = FL.toList
206+ w4x8 <- P.takeEQ 4 s
207+ pure (BO.word32 (BS.pack w4x8))
208+
209+-- uuid is encode as 4 32-bit words because of its convenient 32-bit tuple encoding
210+uuidP :: Parser IO Word8 UUID
211+uuidP = do
212+ u1 <- word32P
213+ u2 <- word32P
214+ u3 <- word32P
215+ --u4 <- word32P
216+ --pure (UUID (UUIDBase.fromWords u1 u2 u3 u4))-}
217+ --(UUID . UUIDBase.fromWords) <$> word32P <*> word32P <*> word32P <*> word32P
218+ UUID . UUIDBase.fromWords u1 u2 u3 <$> word32P
112219
113220type NewConnectionHandler msg = IO (Maybe msg)
114221
115−type NewMessageHandler msg resp = msg -> IO (HandlerResponse resp)
116−
117−serve :: (Show msg, Serialise msg, Serialise resp) =>
118− NewConnectionHandler resp ->
119− NewMessageHandler msg resp ->
222+type NewMessageHandler req resp = req -> IO resp
223+
224+-- | Listen for new connections and handle requests which are passed the server state 's'. The MVar SockAddr can be be optionally used to know when the server is ready for processing requests.
225+serve ::
226+ RequestHandlers s->
227+ s ->
120228 HostAddr ->
121229 PortNumber ->
122230 Maybe (MVar SockAddr) ->
123231 IO Bool
124−serve connhandler msghandler hostaddr port mSockLock = do
125− let handleSock sock = do
126− putStrLn "handleSock"
127− let messageHandler msg = do
128− putStrLn $ "GOT MSG " ++ show msg
129− case msg of
130− Response{} -> putStrLn "client sent response"
131− ResponseExpectedRequest requestID val -> do
132− putStrLn "ResponseExp"
133− resp <- msghandler val
134− case resp of
135− HandlerResponse responseVal -> sendMessage (Response requestID responseVal) sock
136− NoResponse -> error "attempt to return non-response to expected response message"
137− HandlerException _ -> error "TODO HandlerException"
138− AsyncRequest _ val -> do
139− putStrLn "AsyncReq"
140− void $ msghandler val
141− --no response necessaryxs
142− ExceptionResponse{} -> putStrLn "client sent exception response"
143− -- allow the server to send an async welcome message to the new client, if necessary
144− mResp <- connhandler
145− case mResp of
146− Nothing -> pure ()
147− Just resp -> do
148− requestID <- UUID <$> UUIDBase.nextRandom
149− sendMessage (AsyncRequest requestID resp) sock
150− drainSocketMessages sock messageHandler
151− serially (S.unfold (SA.acceptOnAddrWith [(ReuseAddr,1)] mSockLock) (hostaddr, port)) & parallely . S.mapM (handleWithM handleSock) & S.drain
232+serve userMsgHandlers serverState hostaddr port mSockLock = do
233+ let
234+ handleSock sock = do
235+ lockingSocket <- newLock sock
236+ drainSocketMessages sock (serverEnvelopeHandler lockingSocket userMsgHandlers serverState)
237+
238+ S.serially (S.unfold (SA.acceptOnAddrWith [(ReuseAddr,1)] mSockLock) (hostaddr, port)) & S.parallely . S.mapM (handleWithM handleSock) & S.drain
152239 pure True
153240
154−--add callback to allow for responses via socket
155−type MessageHandler a = Message a -> IO ()
241+openEnvelope :: forall s. (Serialise s, Typeable s) => Envelope -> Maybe s
242+openEnvelope (Envelope eprint _ _ bytes) =
243+ if eprint == fingerprint (undefined :: s) then
244+ case deserialise bytes of
245+ Left err -> error (show err)
246+ Right v -> Just v
247+ else
248+ Nothing
156249
157−type AsyncMessageHandler a = a -> IO ()
250+matchEnvelope :: forall a b s. (Serialise a, Serialise b, Typeable b) =>
251+ Envelope ->
252+ (ConnectionState s -> a -> IO b) ->
253+ Maybe (ConnectionState s -> a -> IO b, a)
254+matchEnvelope envelope dispatchf =
255+ case openEnvelope envelope :: Maybe a of
256+ Nothing -> Nothing
257+ Just decoded -> Just (dispatchf, decoded)
258+
259+-- | Called by `serve` to process incoming envelope requests. Never returns, so use `async` to spin it off on another thread.
260+serverEnvelopeHandler ::
261+ Locking Socket
262+ -> RequestHandlers s
263+ -> s
264+ -> Envelope
265+ -> IO ()
266+serverEnvelopeHandler _ _ _ (Envelope _ TimeoutResponseMessage _ _) = pure ()
267+serverEnvelopeHandler _ _ _ (Envelope _ ExceptionResponseMessage _ _) = pure ()
268+serverEnvelopeHandler _ _ _ (Envelope _ ResponseMessage _ _) = pure ()
269+serverEnvelopeHandler sockLock msgHandlers serverState envelope@(Envelope _ (RequestMessage timeoutms) msgId _) = do
270+ --find first matching handler
271+ let runTimeout :: IO b -> IO (Maybe b)
272+ runTimeout m =
273+ if timeoutms == 0 then
274+ (Just <$> m) `catch` timeoutExcHandler
275+ else
276+ (timeout (fromIntegral timeoutms) m) `catch` timeoutExcHandler
277+ --allow server-side function to throw TimeoutError which is caught here and becomes TimeoutError value
278+ timeoutExcHandler :: TimeoutException -> IO (Maybe b)
279+ timeoutExcHandler _ = pure Nothing
280+
281+ sState = ConnectionState {
282+ connectionServerState = serverState,
283+ connectionSocket = sockLock
284+ }
285+
286+ firstMatcher (RequestHandler msghandler) Nothing =
287+ case matchEnvelope envelope msghandler of
288+ Nothing -> pure Nothing
289+ Just (dispatchf, decoded) -> do
290+ --TODO add exception handling
291+ mResponse <- runTimeout (dispatchf sState decoded)
292+ let envelopeResponse =
293+ case mResponse of
294+ Just response ->
295+ Envelope (fingerprint response) ResponseMessage msgId (serialise response)
296+ Nothing ->
297+ Envelope (fingerprint TimeoutError) TimeoutResponseMessage msgId BS.empty
298+ sendEnvelope envelopeResponse sockLock
299+ pure (Just ())
300+ firstMatcher (AsyncRequestHandler msghandler) Nothing =
301+ case matchEnvelope envelope msghandler of
302+ Nothing -> pure Nothing
303+ Just (dispatchf, decoded) -> do
304+ _ <- dispatchf sState decoded
305+ pure (Just ())
306+ firstMatcher _ acc = pure acc
307+ eExc <- try $ foldM_ (flip firstMatcher) Nothing msgHandlers :: IO (Either SomeException ())
308+ case eExc of
309+ Left exc ->
310+ let env = Envelope (fingerprint (show exc)) ExceptionResponseMessage msgId (serialise (show exc)) in
311+ sendEnvelope env sockLock
312+ Right () -> pure ()
158313
159−drainSocketMessages :: Serialise msg => Socket -> MessageHandler msg -> IO ()
160−drainSocketMessages sock msgHandler = do
161− let sockStream = S.unfold readWithBufferOf (1024 * 4, sock)
162− handler bs = do
163− --print ("drain handler", bs)
164− case deserialise bs of
165− Left err ->
166− print err
167− Right val -> do
168− --putStrLn "deserialized value for msgHandler"
169− msgHandler val --add response function
170− S.drain $ S.parseManyD messageBoundaryP sockStream & S.mapM handler
171−
172−fromOctets :: [Word8] -> Word32
173−fromOctets = foldl' accum 0
174− where
175− accum a o = (a `shiftL` 8) .|. fromIntegral o
176314
177−octets :: Word32 -> [Word8]
178−octets w =
179− [ fromIntegral (w `shiftR` 24)
180− , fromIntegral (w `shiftR` 16)
181− , fromIntegral (w `shiftR` 8)
182− , fromIntegral w
183− ]
315+type EnvelopeHandler = Envelope -> IO ()
316+
317+drainSocketMessages :: Socket -> EnvelopeHandler -> IO ()
318+drainSocketMessages sock envelopeHandler = do
319+ let sockStream = S.unfold readWithBufferOf (1024 * 4, sock)
320+ S.drain $ S.serially $ S.parseMany envelopeP sockStream & S.mapM envelopeHandler
184321
185322--send length-tagged bytestring, perhaps should be in network byte order?
186−sendMessage :: Serialise a => a -> Socket -> IO ()
187−sendMessage msg socket' = do
188− putStrLn ("sending bytes: " ++ show (blen <> bytes))
189− writeChunk socket' (toArrayS (blen <> bytes))
190− where
191− bytes = serialise msg
192− len = BS.length bytes
193− blen = BS.pack (octets (fromIntegral len))
194−
195−
196−--from streamly-bytestring
197−-- | Convert a 'ByteString' to an array of 'Word8'. This function unwraps the
198−-- 'ByteString' and wraps it with 'Array' constructors and hence the operation
199−-- is performed in constant time.
200−{-# INLINE toArrayS #-}
201−toArrayS :: BS.ByteString -> SA.Array Word8
202−--slow path
203−--toArrayS = SA.fromList . BS.unpack
204−toArrayS (BSI.PS fp off len) = SA.Array nfp endPtr
205− where
206− nfp = fp `plusForeignPtr` off
207− endPtr = unsafeForeignPtrToPtr nfp `plusPtr` len `plusPtr` 1 -- ? why +1?
323+sendEnvelope :: Envelope -> Locking Socket -> IO ()
324+sendEnvelope envelope sockLock = do
325+ let envelopebytes = encodeEnvelope envelope
326+ fullbytes = envelopebytes
327+ --Socket.sendAll syscalls send() on a loop until all the bytes are sent, so we need socket locking here to account for serialized messages of size > PIPE_BUF
328+ withLock sockLock $ \socket' ->
329+ Socket.sendAll socket' fullbytes
330+ --traceShowM ("sendEnvelope", envelope)
331+ traceBytes "sendEnvelope" fullbytes
208332
333+fingerprint :: Typeable a => a -> Fingerprint
334+fingerprint = typeRepFingerprint . typeOf
335+
336+fromArray :: Arr.Array Word8 -> BSI.ByteString
337+fromArray Arr.Array {..}
338+ | aLen == 0 = mempty
339+ | otherwise = BSI.PS aStart 0 aLen
340+ where
341+ aStartPtr = unsafeForeignPtrToPtr aStart
342+ aLen = aEnd `minusPtr` aStartPtr