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module Tcp (runServer) where
import Control.Concurrent (forkFinally)
import qualified Control.Exception as E
import Control.Monad (forever, void)
import Intro
import Network.Socket
( AddrInfoFlag (AI_PASSIVE)
, HostName
, ServiceName
, Socket
, SocketOption (ReuseAddr)
, SocketType (Stream)
, accept
, addrAddress
, addrFlags
, addrSocketType
, bind
, close
, defaultHints
, getAddrInfo
, gracefulClose
, listen
, openSocket
, setCloseOnExecIfNeeded
, setSocketOption
, withFdSocket
, withSocketsDo
)
runServer :: Maybe HostName -> ServiceName -> (Socket -> IO a) -> IO a
runServer host port server = withSocketsDo $ do
addr <- resolve
E.bracket (open addr) close go
where
resolve = do
let hints = defaultHints{addrFlags = [AI_PASSIVE], addrSocketType = Stream}
head <$> getAddrInfo (Just hints) host (Just port)
open addr = E.bracketOnError (openSocket addr) close $ \sock -> do
setSocketOption sock ReuseAddr 1
withFdSocket sock setCloseOnExecIfNeeded
bind sock $ addrAddress addr
listen sock 1024
pure sock
go :: Socket -> IO a
go sock = forever
$ E.bracketOnError (accept sock) (close . fst)
$ \(conn, _peer) ->
void
$ forkFinally (server conn) (const $ gracefulClose conn 5000)
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