{-# LANGUAGE CPP #-} -- | Converting network 'Socket's to streams. module System.IO.Streams.Network ( -- * Sockets to Streams socketToStreams , socketToStreamsWithBufferSize ) where ------------------------------------------------------------------------------ import Control.Exception (catch) import qualified Data.ByteString.Char8 as S import qualified Data.ByteString.Internal as S import Foreign.ForeignPtr (newForeignPtr, withForeignPtr) import Foreign.Marshal.Alloc (finalizerFree, mallocBytes) import Network.Socket (Socket) import qualified Network.Socket as N import qualified Network.Socket.ByteString as NB import Prelude (IO, Int, Maybe (..), return, ($!), (<=), (>>=)) import System.IO.Error (ioError, isEOFError) ------------------------------------------------------------------------------ import System.IO.Streams.Internal (InputStream, OutputStream) import qualified System.IO.Streams.Internal as Streams ------------------------------------------------------------------------------ bUFSIZ :: Int bUFSIZ = 4096 ------------------------------------------------------------------------------ -- | Converts a 'Socket' to an 'InputStream' \/ 'OutputStream' pair. Note that, -- as is usually the case in @io-streams@, writing a 'Nothing' to the generated -- 'OutputStream' does not cause the underlying 'Socket' to be closed. socketToStreams :: Socket -> IO (InputStream S.ByteString, OutputStream S.ByteString) socketToStreams = socketToStreamsWithBufferSize bUFSIZ ------------------------------------------------------------------------------ -- | Converts a 'Socket' to an 'InputStream' \/ 'OutputStream' pair, with -- control over the size of the receive buffers. Note that, as is usually the -- case in @io-streams@, writing a 'Nothing' to the generated 'OutputStream' -- does not cause the underlying 'Socket' to be closed. socketToStreamsWithBufferSize :: Int -- ^ how large the receive buffer should be -> Socket -- ^ network socket -> IO (InputStream S.ByteString, OutputStream S.ByteString) socketToStreamsWithBufferSize bufsiz socket = do is <- Streams.makeInputStream input os <- Streams.makeOutputStream output return $! (is, os) where #if MIN_VERSION_network(2,4,0) recv buf = N.recvBuf socket buf bufsiz `catch` \ioe -> if isEOFError ioe then return 0 else ioError ioe mkFp = mallocBytes bufsiz >>= newForeignPtr finalizerFree input = do fp <- mkFp n <- withForeignPtr fp recv return $! if n <= 0 then Nothing else Just $! S.fromForeignPtr fp 0 n #else input = do s <- NB.recv socket bufsiz return $! if S.null s then Nothing else Just s #endif output Nothing = return $! () output (Just s) = if S.null s then return $! () else NB.sendAll socket s