mongodb/Database/MongoDB/Internal/Network.hs

53 lines
1.7 KiB
Haskell

-- | Compatibility layer for network package, including newtype 'PortID'
{-# LANGUAGE CPP, PackageImports #-}
module Database.MongoDB.Internal.Network (PortID(..), N.HostName, connectTo) where
#if !MIN_VERSION_network(2, 9, 0)
import qualified Network as N
import System.IO (Handle)
#else
import Control.Exception (bracketOnError)
import Network.BSD as BSD
import qualified Network.Socket as N
import System.IO (Handle, IOMode(ReadWriteMode))
#endif
-- | Wraps network's 'PortNumber'
-- Used to ease compatibility between older and newer network versions.
newtype PortID = PortNumber N.PortNumber deriving (Show, Eq, Ord)
#if !MIN_VERSION_network(2, 9, 0)
-- Unwrap our newtype and use network's PortID and connectTo
connectTo :: N.HostName -- Hostname
-> PortID -- Port Identifier
-> IO Handle -- Connected Socket
connectTo hostname (PortNumber port) = N.connectTo hostname (N.PortNumber port)
#else
-- Copied implementation from network 2.8's 'connectTo', but using our 'PortID' newtype.
-- https://github.com/haskell/network/blob/e73f0b96c9da924fe83f3c73488f7e69f712755f/Network.hs#L120-L129
connectTo :: N.HostName -- Hostname
-> PortID -- Port Identifier
-> IO Handle -- Connected Socket
connectTo hostname (PortNumber port) = do
proto <- BSD.getProtocolNumber "tcp"
bracketOnError
(N.socket N.AF_INET N.Stream proto)
(N.close) -- only done if there's an error
(\sock -> do
he <- BSD.getHostByName hostname
N.connect sock (N.SockAddrInet port (hostAddress he))
N.socketToHandle sock ReadWriteMode
)
#endif