@@ -1,20 +1,18 @@
1−{-# LANGUAGE DerivingVia, DeriveGeneric, RankNTypes, ScopedTypeVariables, MultiParamTypeClasses, OverloadedStrings, GeneralizedNewtypeDeriving, CPP, ExistentialQuantification, StandaloneDeriving, GADTs, RecordWildCards #-}
2−{-# OPTIONS_GHC -fno-warn-orphans #-}
1+{-# LANGUAGE DerivingVia, DeriveGeneric, RankNTypes, ScopedTypeVariables, MultiParamTypeClasses, OverloadedStrings, GeneralizedNewtypeDeriving, TypeApplications, CPP #-}
32{- HLINT ignore "Use lambda-case" -}
43module Network.RPC.Curryer.Server where
4+import Streamly
55import qualified Streamly.Prelude as S
66import Streamly.Network.Socket
77import Streamly.Internal.Network.Socket (handleWithM)
88import Network.Socket as Socket
99import Network.Socket.ByteString as Socket
10−import Streamly.Internal.Data.Parser as P hiding (concatMap)
10+import Streamly.Internal.Data.Parser as P
1111import Codec.Winery
1212import Codec.Winery.Internal (varInt, decodeVarInt, getBytes)
1313import Codec.Winery.Class (mkExtractor)
1414import GHC.Generics
15−import GHC.Fingerprint
16−import Data.Typeable
17−import Control.Concurrent.MVar (MVar, newMVar, withMVar)
15+import Control.Concurrent.MVar (MVar)
1816import Control.Exception
1917import Data.Function ((&))
2018import Data.Word
@@ -26,23 +24,21 @@ import qualified Streamly.Internal.Data.Stream.IsStream as S
2624import qualified Data.Binary as B
2725import qualified Data.UUID as UUIDBase
2826import qualified Data.UUID.V4 as UUIDBase
29−import Control.Monad
30−import Data.Functor
3127
3228import qualified Network.RPC.Curryer.StreamlyAdditions as SA
33−--import Control.Monad
29+import Control.Monad
3430import Data.Hashable
3531import System.Timeout
3632import qualified Network.ByteOrder as BO
37−
33+import Data.Proxy
3834
3935-- for toArrayS conversion
40−import qualified Data.ByteString.Internal as BSI
41−import qualified Streamly.Internal.Data.Array.Storable.Foreign.Types as Arr
36+{-import qualified Data.ByteString.Internal as BSI
37+import qualified Streamly.Internal.Data.Array.Storable.Foreign.Types as SA
38+import Foreign.ForeignPtr (plusForeignPtr)
4239import Foreign.ForeignPtr.Unsafe (unsafeForeignPtrToPtr)
43−import GHC.Ptr (minusPtr)
44−
45−-- define CURRYER_SHOW_BYTES 1
40+import GHC.Ptr (plusPtr)
41+-}
4642#if CURRYER_SHOW_BYTES == 1
4743import Debug.Trace
4844#endif
@@ -54,72 +50,24 @@ traceBytes msg bs = traceShowM (msg, BS.length bs, bs)
5450traceBytes _ _ = pure ()
5551#endif
5652
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
72−
73−type BinaryMessage = BS.ByteString
53+type Timeout = Int
7454
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)
55+data Message a = Response UUID a
56+ | AsyncRequest UUID a
57+ | ResponseExpectedRequest UUID (Maybe Timeout) a
58+ | TimedOutResponse UUID
59+ -- | Services
60+ | ExceptionResponse String
61+ deriving (Generic, Show)
62+ deriving Serialise via WineryVariant (Message a)
8463
85−type TimeoutMicroseconds = Int
64+-- | The response type
65+data HandlerResponse a = NoResponse
66+ | HandlerResponse a
67+ | HandlerException a
68+ deriving Generic
69+ deriving Serialise via WineryVariant (HandlerResponse a)
8670
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−
12371--avoid orphan instance
12472newtype UUID = UUID { _unUUID :: UUIDBase.UUID }
12573 deriving (Show, Eq, B.Binary, Hashable)
@@ -138,18 +86,12 @@ instance Serialise UUID where
13886 x -> error $ "invalid schema element " <> show x
13987 decodeCurrent = B.decode . BSL.fromStrict <$> (decodeVarInt >>= getBytes)
14088
141−-- | Errors from remote calls.
89+
14290data ConnectionError = CodecError String -- show of WineryException from exception initiator which cannot otherwise be transmitted over a line due to dependencies on TypeReps
14391 | TimeoutError
144− | ExceptionError String
14592 deriving (Generic, Show, Eq)
14693 deriving Serialise via WineryVariant ConnectionError
14794
148−data TimeoutException = TimeoutException
149− deriving Show
150−
151−instance Exception TimeoutException
152−
15395type HostAddr = (Word8, Word8, Word8, Word8)
15496
15597allHostAddrs,localHostAddr :: HostAddr
@@ -157,186 +99,123 @@ allHostAddrs = (0,0,0,0)
15799localHostAddr = (127,0,0,1)
158100
159101-- Each message is length-prefixed by a 32-bit unsigned length.
160−envelopeP :: Parser IO Word8 Envelope
161−envelopeP = do
162− let msgTypeP = (P.satisfy (== 0) *>
163− (RequestMessage . fromIntegral <$> 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 <$> word64P <*> word64P
195−
196−word64P :: Parser IO Word8 Word64
197−word64P = do
102+messageBoundaryP :: Parser IO Word8 BS.ByteString
103+messageBoundaryP = do
198104 let s = FL.toList
199− b <- P.takeEQ 8 s
200− pure (BO.word64 (BS.pack b))
201−
202−--parse a 32-bit integer from network byte order
203−word32P :: Parser IO Word8 Word32
204−word32P = do
205− let s = FL.toList
206− w4x8 <- P.takeEQ 4 s
207− pure (BO.word32 (BS.pack w4x8))
208−
209−-- uuid is encode as 4 32-bit words because of its convenient 32-bit tuple encoding
210−uuidP :: Parser IO Word8 UUID
211−uuidP = do
212− u1 <- word32P
213− u2 <- word32P
214− u3 <- word32P
215− --u4 <- word32P
216− --pure (UUID (UUIDBase.fromWords u1 u2 u3 u4))-}
217− --(UUID . UUIDBase.fromWords) <$> word32P <*> word32P <*> word32P <*> word32P
218− UUID . UUIDBase.fromWords u1 u2 u3 <$> word32P
105+ w4x8 <- P.take 4 s
106+ --traceShowM ("w4x8"::String, w4x8)
107+ let c = fromIntegral (BO.word32 (BS.pack w4x8))
108+ --traceShowM ("c"::String, c)
109+ vals <- P.take c s
110+ let bytes = BS.pack vals
111+ --traceShowM ("parsedBytes"::String, c, BS.length bytes, bytes)
112+ pure bytes
219113
220114type NewConnectionHandler msg = IO (Maybe msg)
221115
222−type NewMessageHandler req resp = req -> IO resp
223−
224−-- | Listen for new connections and handle requests which are passed the server state 's'. The MVar SockAddr can be be optionally used to know when the server is ready for processing requests.
225−serve ::
226− RequestHandlers s->
227− s ->
116+type NewMessageHandler req resp = req -> IO (HandlerResponse resp)
117+
118+serve :: forall req resp. (Show req, Serialise req, Serialise resp) =>
119+ NewConnectionHandler resp ->
120+ NewMessageHandler req resp ->
228121 HostAddr ->
229122 PortNumber ->
230123 Maybe (MVar SockAddr) ->
231124 IO Bool
232−serve userMsgHandlers serverState hostaddr port mSockLock = do
125+serve connhandler userMsgHandler hostaddr port mSockLock = do
233126 let
127+ decoder :: NewMessageHandler req resp -> Decoder (Message req)
128+ decoder _ =
129+ case getDecoder (schema (Proxy @(Message req))) of
130+ Left exc -> error (show exc)
131+ Right dec -> dec
234132 handleSock sock = do
235− lockingSocket <- newLock sock
236− drainSocketMessages sock (serverEnvelopeHandler lockingSocket userMsgHandlers serverState)
237−
238− S.serially (S.unfold (SA.acceptOnAddrWith [(ReuseAddr,1)] mSockLock) (hostaddr, port)) & S.parallely . S.mapM (handleWithM handleSock) & S.drain
133+ -- allow the server to send an async welcome message to the new client, if necessary
134+ mResp <- connhandler
135+ case mResp of
136+ Nothing -> pure ()
137+ Just resp -> do
138+ requestID <- UUID <$> UUIDBase.nextRandom
139+ sendMessage (AsyncRequest requestID resp) sock
140+ drainSocketMessages sock (decoder userMsgHandler) (serverMessageHandler sock userMsgHandler)
141+ serially (S.unfold (SA.acceptOnAddrWith [(ReuseAddr,1)] mSockLock) (hostaddr, port)) & parallely . S.mapM (handleWithM handleSock) & S.drain
239142 pure True
240143
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
249−
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
144+serverMessageHandler :: forall req resp. (Show req,
145+ Serialise req,
146+ Serialise resp)
147+ => Socket
148+ -> NewMessageHandler req resp
149+ -> Message req
265150 -> 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 ()
313−
314−
315−type EnvelopeHandler = Envelope -> IO ()
316−
317−drainSocketMessages :: Socket -> EnvelopeHandler -> IO ()
318−drainSocketMessages sock envelopeHandler = do
151+serverMessageHandler sock requestMessageHandler msg = do
152+ --putStrLn $ "GOT MSG " ++ show msg
153+ let --runTimeout :: IO (HandlerResponse resp) -> IO (Maybe (HandlerResponse resp))
154+ runTimeout mTimeout m = case mTimeout of
155+ Nothing -> Just <$> m
156+ Just timeoutMicroseconds -> timeout timeoutMicroseconds m
157+ case msg of
158+ Response{} -> putStrLn "client sent response"
159+ ResponseExpectedRequest requestID mTimeout val -> do
160+ resp <- runTimeout mTimeout (requestMessageHandler val)
161+ case resp of
162+ Just (HandlerResponse responseVal) -> sendMessage (Response requestID responseVal) sock
163+ Just NoResponse -> error "attempt to return non-response to expected response message"
164+ Just (HandlerException _) -> error "TODO HandlerException"
165+ Nothing ->
166+ sendMessage (TimedOutResponse @(Message resp) requestID) sock
167+ AsyncRequest _ val -> do
168+ void $ requestMessageHandler val
169+ --no response necessary
170+ ExceptionResponse{} -> putStrLn "client sent exception response"
171+ TimedOutResponse{} -> putStrLn "client sent timed out response"
172+
173+--add callback to allow for responses via socket
174+type MessageHandler a = Message a -> IO ()
175+
176+type AsyncMessageHandler a = a -> IO ()
177+
178+
179+
180+drainSocketMessages :: Serialise msg => Socket -> Decoder (Message msg) -> MessageHandler msg -> IO ()
181+drainSocketMessages sock decoder msgHandler = do
319182 let sockStream = S.unfold readWithBufferOf (1024 * 4, sock)
320− S.drain $ S.serially $ S.parseMany envelopeP sockStream & S.mapM envelopeHandler
183+ handler bs = do
184+ let decoded = evalDecoder decoder bs
185+ msgHandler decoded
186+ S.drain $ serially $ S.parseMany messageBoundaryP sockStream & S.mapM handler
321187
322188--send length-tagged bytestring, perhaps should be in network byte order?
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
332−
333−fingerprint :: Typeable a => a -> Fingerprint
334−fingerprint = typeRepFingerprint . typeOf
189+sendMessage :: Serialise a => Message a -> Socket -> IO ()
190+sendMessage msg socket' = do
191+ let
192+ msgbytes = serialiseOnly msg
193+ fullbytes = lenbytes <> msgbytes
194+ len = BS.length msgbytes
195+ lenbytes = BO.bytestring32 (fromIntegral len)
196+
197+ byteCount <- Socket.send socket' fullbytes
198+ when (byteCount /= BS.length fullbytes) (error "bytes sent mismatch")
199+ traceBytes "sent bytes" fullbytes
200+
201+
202+
203+--from streamly-bytestring
204+-- | Convert a 'ByteString' to an array of 'Word8'. This function unwraps the
205+-- 'ByteString' and wraps it with 'Array' constructors and hence the operation
206+-- is performed in constant time.
207+{-
208+{-# INLINE toArrayS #-}
209+toArrayS :: BS.ByteString -> SA.Array Word8
210+--slow path
211+--toArrayS = SA.fromList . BS.unpack
212+toArrayS (BSI.PS fp off len) = SA.Array nfp endPtr
213+ where
214+ nfp = fp `plusForeignPtr` off
215+ endPtr = unsafeForeignPtrToPtr nfp `plusPtr` len `plusPtr` 1 -- ? why +1?
335216
336−fromArray :: Arr.Array Word8 -> BSI.ByteString
337−fromArray Arr.Array {..}
338− | aLen == 0 = mempty
339− | otherwise = BSI.PS aStart 0 aLen
217+toArraySlow :: BS.ByteString -> SA.Array Word8
218+toArraySlow bs = arr
340219 where
341− aStartPtr = unsafeForeignPtrToPtr aStart
342− aLen = aEnd `minusPtr` aStartPtr
220+ arr = SA.fromList (BS.unpack bs)
221+-}