warp-3.2.0: Network/Wai/Handler/Warp/HTTP2/Worker.hs
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE PatternGuards #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE BangPatterns #-}
module Network.Wai.Handler.Warp.HTTP2.Worker (
Responder
, response
, worker
) where
#if __GLASGOW_HASKELL__ < 709
import Control.Applicative
import Data.Monoid (mempty)
#endif
import Control.Concurrent.STM
import Control.Exception (SomeException(..), AsyncException(..))
import qualified Control.Exception as E
import Control.Monad (when)
import Data.ByteString.Builder (byteString)
import Data.Hashable (hash)
import qualified Network.HTTP.Types as H
import Network.HTTP2
import Network.Wai
import Network.Wai.Handler.Warp.File
import Network.Wai.Handler.Warp.FileInfoCache
import Network.Wai.Handler.Warp.HTTP2.EncodeFrame
import Network.Wai.Handler.Warp.HTTP2.Manager
import Network.Wai.Handler.Warp.HTTP2.Types
import Network.Wai.Handler.Warp.Header
import Network.Wai.Handler.Warp.IORef
import qualified Network.Wai.Handler.Warp.Response as R
import qualified Network.Wai.Handler.Warp.Settings as S
import qualified Network.Wai.Handler.Warp.Timeout as T
import Network.Wai.Handler.Warp.Types
import Network.Wai.Internal (Response(..), ResponseReceived(..), ResponseReceived(..))
----------------------------------------------------------------
-- | The wai definition is 'type Application = Request -> (Response -> IO ResponseReceived) -> IO ResponseReceived'.
-- This type implements the second argument (Response -> IO ResponseReceived)
-- with extra arguments.
type Responder = ThreadContinue -> T.Handle -> Stream -> Request ->
Response -> IO ResponseReceived
-- | This function is passed to workers.
-- They also pass 'Response's from 'Application's to this function.
-- This function enqueues commands for the HTTP/2 sender.
response :: InternalInfo -> S.Settings -> Context -> Manager -> Responder
response ii settings Context{outputQ} mgr tconf th strm req rsp
| R.hasBody s0 = case rsp of
ResponseStream _ _ strmbdy
| isHead -> responseNoBody s0 hs0
| otherwise -> responseStreaming strmbdy
ResponseBuilder _ _ b
| isHead -> responseNoBody s0 hs0
| otherwise -> responseBuilderBody s0 hs0 b
ResponseFile _ _ p mp -> responseFileXXX p mp
ResponseRaw _ _ -> error "HTTP/2 does not support ResponseRaw"
| otherwise = responseNoBody s0 hs0
where
!isHead = requestMethod req == H.methodHead
!s0 = responseStatus rsp
!hs0 = responseHeaders rsp
!logger = S.settingsLogger settings
-- Ideally, log messages should be written when responses are
-- actually sent. But there is no way to keep good memory usage
-- (resist to Request leak) and throughput. By compromise,
-- log message are written here even the window size of streams
-- is 0.
responseNoBody s hs = do
logger req s Nothing
setThreadContinue tconf True
let rspn = RspnNobody s hs
out = ORspn strm rspn
enqueueOutput outputQ out
return ResponseReceived
responseBuilderBody s hs bdy = do
logger req s Nothing
setThreadContinue tconf True
let rspn = RspnBuilder s hs bdy
out = ORspn strm rspn
enqueueOutput outputQ out
return ResponseReceived
responseFileXXX path Nothing = do
let !h = hash $ rawPathInfo req
efinfo <- E.try $ fileInfo' ii h path
case efinfo of
Left (_ex :: E.IOException) -> response404
Right finfo -> case conditionalRequest finfo hs0 (indexRequestHeader (requestHeaders req)) of
WithoutBody s -> responseNoBody s hs0
WithBody s hs beg len -> responseFile2XX s hs h path (Just (FilePart beg len (fileInfoSize finfo)))
responseFileXXX path mpart = responseFile2XX s0 hs0 h path mpart
where
!h = hash $ rawPathInfo req
responseFile2XX s hs h path mpart
| isHead = do
logger req s Nothing
responseNoBody s hs
| otherwise = do
logger req s (filePartByteCount <$> mpart)
setThreadContinue tconf True
let rspn = RspnFile s hs h path mpart
out = ORspn strm rspn
enqueueOutput outputQ out
return ResponseReceived
response404 = responseBuilderBody s hs body
where
s = H.notFound404
hs = R.replaceHeader H.hContentType "text/plain; charset=utf-8" hs0
body = byteString "File not found"
responseStreaming strmbdy = do
logger req s0 Nothing
-- We must not exit this WAI application.
-- If the application exits, streaming would be also closed.
-- So, this work occupies this thread.
--
-- We need to increase the number of workers.
spawnAction mgr
-- After this work, this thread stops to decease
-- the number of workers.
setThreadContinue tconf False
-- Since 'StreamingBody' is loop, we cannot control it.
-- So, let's serialize 'Builder' with a designated queue.
tbq <- newTBQueueIO 10 -- fixme: hard coding: 10
let rspn = RspnStreaming s0 hs0 tbq
out = ORspn strm rspn
enqueueOutput outputQ out
let push b = do
atomically $ writeTBQueue tbq (SBuilder b)
T.tickle th
flush = atomically $ writeTBQueue tbq SFlush
_ <- strmbdy push flush
atomically $ writeTBQueue tbq SFinish
deleteMyId mgr
return ResponseReceived
worker :: Context -> S.Settings -> Application -> Responder -> T.Manager -> IO ()
worker ctx@Context{inputQ,controlQ} set app responder tm = do
sinfo <- newStreamInfo
tcont <- newThreadContinue
E.bracket (T.registerKillThread tm) T.cancel $ go sinfo tcont
where
go sinfo tcont th = do
setThreadContinue tcont True
ex <- E.try $ do
T.pause th
inp@(Input strm req) <- atomically $ readTQueue inputQ
setStreamInfo sinfo inp
T.resume th
T.tickle th
app req $ responder tcont th strm req
cont1 <- case ex of
Right ResponseReceived -> return True
Left e@(SomeException _)
-- killed by the local worker manager
| Just ThreadKilled <- E.fromException e -> return False
-- killed by the local timeout manager
| Just T.TimeoutThread <- E.fromException e -> do
cleanup sinfo Nothing
return True
| otherwise -> do
cleanup sinfo $ Just e
return True
cont2 <- getThreadContinue tcont
clearStreamInfo sinfo
when (cont1 && cont2) $ go sinfo tcont th
cleanup sinfo me = do
minp <- getStreamInfo sinfo
case minp of
Nothing -> return ()
Just (Input strm req) -> do
closed ctx strm Killed
let frame = resetFrame InternalError (streamNumber strm)
enqueueControl controlQ $ CFrame frame
case me of
Nothing -> return ()
Just e -> S.settingsOnException set (Just req) e
----------------------------------------------------------------
-- | It would nice if responders could return values to workers.
-- Unfortunately, 'ResponseReceived' is already defined in WAI 2.0.
-- It is not wise to change this type.
-- So, a reference is shared by a responder and its worker.
-- The reference refers a value of this type as a return value.
-- If 'True', the worker continue to serve requests.
-- Otherwise, the worker get finished.
newtype ThreadContinue = ThreadContinue (IORef Bool)
newThreadContinue :: IO ThreadContinue
newThreadContinue = ThreadContinue <$> newIORef True
setThreadContinue :: ThreadContinue -> Bool -> IO ()
setThreadContinue (ThreadContinue ref) x = writeIORef ref x
getThreadContinue :: ThreadContinue -> IO Bool
getThreadContinue (ThreadContinue ref) = readIORef ref
----------------------------------------------------------------
-- | The type to store enough information for 'settingsOnException'.
newtype StreamInfo = StreamInfo (IORef (Maybe Input))
newStreamInfo :: IO StreamInfo
newStreamInfo = StreamInfo <$> newIORef Nothing
clearStreamInfo :: StreamInfo -> IO ()
clearStreamInfo (StreamInfo ref) = writeIORef ref Nothing
setStreamInfo :: StreamInfo -> Input -> IO ()
setStreamInfo (StreamInfo ref) inp = writeIORef ref $ Just inp
getStreamInfo :: StreamInfo -> IO (Maybe Input)
getStreamInfo (StreamInfo ref) = readIORef ref