58 lines
1.4 KiB
Haskell
58 lines
1.4 KiB
Haskell
module Server.Communication.Receive where
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import qualified Control.Concurrent.STM as STM
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import Control.Exception
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import Control.Monad.IO.Class
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import qualified Data.Aeson as A
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import qualified Data.ByteString as B
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import qualified Data.ByteString.Lazy.Char8 as B8
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import Foreign.Marshal hiding (void)
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import Network.Socket
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-- internal imports
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import Library.Types
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import Server.Communication.Send
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import Server.Types
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-- | receive a 'ClientMessage'
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receiveMessage
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:: STM.TMVar Socket
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-> STM.TQueue ClientMessage
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-> STM.TMVar [ClientComms]
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-> IO ()
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receiveMessage sockContainer queue clientList = do
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sock <- STM.atomically $ STM.readTMVar sockContainer
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let maxBufferLength = 4096
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mMsg <- do
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ptr <- mallocArray maxBufferLength
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eBufferLength <-
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try $ recvBuf sock ptr maxBufferLength
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bufferLength <- case eBufferLength of
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Left (e :: IOException) -> do
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putStrLn ("Socket vanished, cleaning up after " <> show e)
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dropClient clientList sock
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pure 0
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Right len -> pure len
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msg <- B.pack <$> peekArray bufferLength ptr
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let mJsonMsg = A.decode' $ B8.fromStrict msg :: Maybe ClientMessage
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free ptr
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if bufferLength > 0
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then
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pure mJsonMsg
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else
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pure Nothing
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maybe
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(pure ())
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(\msg -> do
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liftIO $ STM.atomically $ STM.writeTQueue queue msg
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-- when (msg == IdRequest) (threadDelay $ 10 ^ 3)
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)
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mMsg
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