Files
skat/src/Skat/AI/Server.hs
T

111 lines
3.4 KiB
Haskell

module Skat.AI.Server where
import qualified Network.Socket as Net
import qualified System.IO as Sys
import Control.Concurrent
import Control.Concurrent.Chan
import Control.Monad (forever)
import Control.Monad.Reader
import Data.List.Split
data Buffering = NoBuffering
| LengthBuffering
| DelimiterBuffering String
deriving (Show)
data ServerEnv = ServerEnv
{ buffering :: Buffering -- ^ Buffermode
, socket :: Net.Socket -- ^ the socket used to communicate
, global :: Chan String
, onReceive :: OnReceive
}
instance Show ServerEnv where
show env = "A Server"
type Server = ReaderT ServerEnv IO
type OnReceive = Sys.Handle -> Net.SockAddr -> String -> Server ()
broadcast :: String -> Server ()
broadcast msg = do
bufmode <- asks buffering
chan <- asks global
case bufmode of
DelimiterBuffering delim -> liftIO $ writeChan chan $ msg ++ delim
_ -> liftIO $ writeChan chan msg
send :: Sys.Handle -> String -> Server ()
send connhdl msg = do
bufmode <- asks buffering
case bufmode of
DelimiterBuffering delim -> liftIO $ Sys.hPutStr connhdl $ msg ++ delim
_ -> liftIO $ Sys.hPutStr connhdl msg
-- | Initialize a new server with the given port number and buffering mode
initServer :: Net.PortNumber -> Buffering -> OnReceive -> IO ServerEnv
initServer port buffermode handler = do
sock <- Net.socket Net.AF_INET Net.Stream 0
Net.setSocketOption sock Net.ReuseAddr 1
addr <- Net.addrAddress <$> resolve
Net.bind sock addr
Net.listen sock 5
chan <- newChan
forkIO $ forever $ do
msg <- readChan chan -- clearing the main channel
return ()
return (ServerEnv buffermode sock chan handler)
where resolve = do
let hints = Net.defaultHints { Net.addrSocketType = Net.Stream }
addrs <- Net.getAddrInfo (Just hints) (Just "127.0.0.1") (Just $ show port)
return $ head addrs
close :: ServerEnv -> IO ()
close = Net.close . socket
-- | Looping over requests and establish connection
procRequests :: Server ()
procRequests = do
sock <- asks socket
(conn, clientaddr) <- liftIO $ Net.accept sock
env <- ask
liftIO $ forkIO $ runReaderT (procMessages conn clientaddr) env
procRequests
-- | Handle one client
procMessages :: Net.Socket -> Net.SockAddr -> Server ()
procMessages conn clientaddr = do
connhdl <- liftIO $ Net.socketToHandle conn Sys.ReadWriteMode
liftIO $ Sys.hSetBuffering connhdl Sys.NoBuffering
globalChan <- asks global
commChan <- liftIO $ dupChan globalChan
reader <- liftIO $ forkIO $ forever $ do
msg <- readChan commChan
Sys.hPutStrLn connhdl msg
handler <- asks onReceive
messages <- liftIO $ Sys.hGetContents connhdl
buffermode <- asks buffering
case buffermode of
DelimiterBuffering delimiter ->
mapM_ (handler connhdl clientaddr) (splitOn delimiter messages)
LengthBuffering -> liftIO $ putStrLn (take 4 messages)
_ -> return ()
-- clean up
liftIO $ do killThread reader
Sys.hClose connhdl
sampleHandler :: OnReceive
sampleHandler connhdl addr query = do
liftIO $ putStrLn $ "new query " ++ query
send connhdl $ "> " ++ query
main :: IO ()
main = do
env <- initServer 4242 LengthBuffering sampleHandler
runReaderT procRequests env