Files
simplexmq/src/Simplex/Messaging/Client.hs
2021-02-26 18:09:26 +04:00

137 lines
4.5 KiB
Haskell

{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
module Simplex.Messaging.Client
( SMPClient,
getSMPClient,
createSMPQueue,
sendSMPMessage,
sendSMPCommand,
SMPClientError (..),
SMPClientConfig (..),
smpDefaultConfig,
)
where
import Control.Concurrent.Async
import Control.Concurrent.STM
import Control.Exception
import Control.Monad
import Control.Monad.Trans.Except
import qualified Data.ByteString.Char8 as B
import Data.Map.Strict (Map)
import qualified Data.Map.Strict as M
import Data.Maybe
import Network.Socket (ServiceName)
import Numeric.Natural
import Simplex.Messaging.Agent.Transmission (SMPServer (..))
import Simplex.Messaging.Server.Transmission
import Simplex.Messaging.Transport
import Simplex.Messaging.Util
import System.IO
data SMPClient = SMPClient
{ action :: Async (),
clientCorrId :: TVar Natural,
sentCommands :: TVar (Map CorrId Request),
sndQ :: TBQueue Transmission,
rcvQ :: TBQueue TransmissionOrError
}
data SMPClientConfig = SMPClientConfig
{ qSize :: Natural,
defaultPort :: ServiceName
}
smpDefaultConfig :: SMPClientConfig
smpDefaultConfig = SMPClientConfig 16 "5223"
data Request = Request
{ queueId :: QueueId,
responseVar :: TMVar (Either SMPClientError Cmd)
}
getSMPClient :: SMPServer -> SMPClientConfig -> IO SMPClient
getSMPClient SMPServer {host, port} SMPClientConfig {qSize, defaultPort} = do
c <-
atomically $
SMPClient undefined <$> newTVar 0 <*> newTVar M.empty <*> newTBQueue qSize <*> newTBQueue qSize
action <- async $ runTCPClient host (fromMaybe defaultPort port) (client c)
return c {action}
where
client :: SMPClient -> Handle -> IO ()
client c h = do
_line <- getLn h -- "Welcome to SMP"
-- TODO test connection failure
raceAny_ [send c h, process c, receive c h]
send :: SMPClient -> Handle -> IO ()
send SMPClient {sndQ} h = forever $ atomically (readTBQueue sndQ) >>= tPut h
receive :: SMPClient -> Handle -> IO ()
receive SMPClient {rcvQ} h = forever $ tGet fromServer h >>= atomically . writeTBQueue rcvQ
process :: SMPClient -> IO ()
process SMPClient {rcvQ, sentCommands} = forever . atomically $ do
(_, (corrId, qId, respOrErr)) <- readTBQueue rcvQ
cs <- readTVar sentCommands
case M.lookup corrId cs of
Nothing -> return () -- TODO send to message channel or error channel
Just Request {queueId, responseVar} -> do
modifyTVar sentCommands $ M.delete corrId
putTMVar responseVar $
if queueId == qId
then case respOrErr of
Left e -> Left $ SMPResponseError e
Right (Cmd _ (ERR e)) -> Left $ SMPServerError e
Right r -> Right r
else Left SMPQueueIdError
data SMPClientError
= SMPServerError ErrorType
| SMPResponseError ErrorType
| SMPQueueIdError
| SMPUnexpectedResponse
| SMPResponseTimeout
| SMPClientError
deriving (Eq, Show, Exception)
createSMPQueue :: SMPClient -> RecipientKey -> ExceptT SMPClientError IO (RecipientId, SenderId)
createSMPQueue c rKey = do
sendSMPCommand c "" "" (Cmd SRecipient $ NEW rKey) >>= \case
Cmd _ (IDS rId sId) -> return (rId, sId)
_ -> throwE SMPUnexpectedResponse
sendSMPMessage :: SMPClient -> SenderKey -> QueueId -> MsgBody -> ExceptT SMPClientError IO ()
sendSMPMessage c sKey qId msg = do
sendSMPCommand c sKey qId (Cmd SSender $ SEND msg) >>= \case
Cmd _ OK -> return ()
_ -> throwE SMPUnexpectedResponse
sendSMPCommand :: SMPClient -> PrivateKey -> QueueId -> Cmd -> ExceptT SMPClientError IO Cmd
sendSMPCommand SMPClient {sndQ, sentCommands, clientCorrId} pKey qId cmd = ExceptT $ do
corrId <- atomically getNextCorrId
t <- signTransmission (corrId, qId, cmd)
atomically (send corrId t) >>= atomically . takeTMVar
where
getNextCorrId :: STM CorrId
getNextCorrId = do
i <- (+ 1) <$> readTVar clientCorrId
writeTVar clientCorrId i
return . CorrId . B.pack $ show i
-- TODO this is a stub - to replace with cryptographic signature
signTransmission :: Signed -> IO Transmission
signTransmission signed = return (pKey, signed)
send :: CorrId -> Transmission -> STM (TMVar (Either SMPClientError Cmd))
send corrId t = do
r <- newEmptyTMVar
modifyTVar sentCommands . M.insert corrId $ Request qId r
writeTBQueue sndQ t
return r