Network/HTTP/Lucu/RequestReader.hs

   1 module Network.HTTP.Lucu.RequestReader
   2     ( requestReader
   3     )
   4     where
   5
   6 import           Control.Concurrent.STM
   7 import           Control.Exception
   8 import           Control.Monad
   9 import qualified Data.ByteString.Lazy.Char8 as B
  10 import           Data.ByteString.Lazy.Char8 (ByteString)
  11 import           Data.Maybe
  12 import qualified Data.Sequence as S
  13 import           Data.Sequence ((<|))
  14 import           Network.Socket
  15 import           Network.HTTP.Lucu.Config
  16 import           Network.HTTP.Lucu.Chunk
  17 import           Network.HTTP.Lucu.DefaultPage
  18 import           Network.HTTP.Lucu.Interaction
  19 import           Network.HTTP.Lucu.Parser
  20 import           Network.HTTP.Lucu.Postprocess
  21 import           Network.HTTP.Lucu.Preprocess
  22 import           Network.HTTP.Lucu.Request
  23 import           Network.HTTP.Lucu.Response
  24 import           Network.HTTP.Lucu.Resource.Tree
  25 import           Prelude hiding (catch)
  26 import           System.IO
  27
  28
  29 requestReader :: Config -> ResTree -> Handle -> SockAddr -> InteractionQueue -> IO ()
  30 requestReader cnf tree h addr tQueue
  31     = cnf `seq` tree `seq` h `seq` addr `seq` tQueue `seq`
  32       do catch (do input <- B.hGetContents h
  33                    acceptRequest input) $ \ exc ->
  34              case exc of
  35                IOException _               -> return ()
  36                AsyncException ThreadKilled -> return ()
  37                BlockedIndefinitely         -> putStrLn "requestReader: blocked indefinitely"
  38                _                           -> print exc
  39     where
  40       acceptRequest :: ByteString -> IO ()
  41       acceptRequest input
  42           -- キューに最大パイプライン深度以上のリクエストが溜まってゐる
  43           -- 時は、それが限度以下になるまで待つ。
  44           = {-# SCC "acceptRequest" #-}
  45             do atomically $ do queue    <- readTVar tQueue
  46                                when (S.length queue >= cnfMaxPipelineDepth cnf)
  47                                     retry
  48
  49                -- リクエストを讀む。パースできない場合は直ちに 400 Bad
  50                -- Request 應答を設定し、それを出力してから切斷するやう
  51                -- に ResponseWriter に通知する。
  52                case parse requestP input of
  53                  (Success req , input') -> acceptParsableRequest req input'
  54                  (IllegalInput, _     ) -> acceptNonparsableRequest BadRequest
  55                  (ReachedEOF  , _     ) -> acceptNonparsableRequest BadRequest
  56
  57       acceptNonparsableRequest :: StatusCode -> IO ()
  58       acceptNonparsableRequest status
  59           = {-# SCC "acceptNonparsableRequest" #-}
  60             do itr <- newInteraction cnf addr Nothing
  61                atomically $ do updateItr itr itrResponse
  62                                              $ \ res -> res {
  63                                                           resStatus = status
  64                                                         }
  65                                writeItr itr itrWillClose True
  66                                writeItr itr itrState     Done
  67                                writeDefaultPage itr
  68                                postprocess itr
  69                                enqueue itr
  70
  71       acceptParsableRequest :: Request -> ByteString -> IO ()
  72       acceptParsableRequest req input
  73           = {-# SCC "acceptParsableRequest" #-}
  74             do itr <- newInteraction cnf addr (Just req)
  75                action
  76                    <- atomically $
  77                       do preprocess itr
  78                          isErr <- readItr itr itrResponse (isError . resStatus)
  79                          if isErr then
  80                              acceptSemanticallyInvalidRequest itr input
  81                            else
  82                              case findResource tree $ reqURI req of
  83                                Nothing -- Resource が無かった
  84                                    -> acceptRequestForNonexistentResource itr input
  85
  86                                Just (rsrcPath, rsrcDef) -- あった
  87                                    -> acceptRequestForExistentResource itr input rsrcPath rsrcDef
  88                action
  89
  90       acceptSemanticallyInvalidRequest :: Interaction -> ByteString -> STM (IO ())
  91       acceptSemanticallyInvalidRequest itr input
  92           = {-# SCC "acceptSemanticallyInvalidRequest" #-}
  93             do writeItr itr itrState Done
  94                writeDefaultPage itr
  95                postprocess itr
  96                enqueue itr
  97                return $ acceptRequest input
  98
  99       acceptRequestForNonexistentResource :: Interaction -> ByteString -> STM (IO ())
 100       acceptRequestForNonexistentResource itr input
 101           = {-# SCC "acceptRequestForNonexistentResource" #-}
 102             do updateItr itr itrResponse
 103                              $ \res -> res {
 104                                          resStatus = NotFound
 105                                        }
 106                writeItr itr itrState Done
 107                writeDefaultPage itr
 108                postprocess itr
 109                enqueue itr
 110                return $ acceptRequest input
 111
 112       acceptRequestForExistentResource :: Interaction -> ByteString -> [String] -> ResourceDef -> STM (IO ())
 113       acceptRequestForExistentResource oldItr input rsrcPath rsrcDef
 114           = {-# SCC "acceptRequestForExistentResource" #-}
 115             do let itr = oldItr { itrResourcePath = Just rsrcPath }
 116                requestHasBody <- readItr itr itrRequestHasBody id
 117                enqueue itr
 118                return $ do runResource rsrcDef itr
 119                            if requestHasBody then
 120                                observeRequest itr input
 121                              else
 122                                acceptRequest input
 123
 124       observeRequest :: Interaction -> ByteString -> IO ()
 125       observeRequest itr input
 126           = {-# SCC "observeRequest" #-}
 127             do isChunked <- atomically $ readItr itr itrRequestIsChunked id
 128                if isChunked then
 129                    observeChunkedRequest itr input
 130                  else
 131                    observeNonChunkedRequest itr input
 132
 133       observeChunkedRequest :: Interaction -> ByteString -> IO ()
 134       observeChunkedRequest itr input
 135           = {-# SCC "observeChunkedRequest" #-}
 136             do action
 137                    <- atomically $
 138                       do isOver <- readItr itr itrReqChunkIsOver id
 139                          if isOver then
 140                              return $ acceptRequest input
 141                            else
 142                              do wantedM <- readItr itr itrReqBodyWanted id
 143                                 if wantedM == Nothing then
 144                                     do wasteAll <- readItr itr itrReqBodyWasteAll id
 145                                        if wasteAll then
 146                                            -- 破棄要求が來た
 147                                            do remainingM <- readItr itr itrReqChunkRemaining id
 148                                               if fmap (> 0) remainingM == Just True then
 149                                                   -- 現在のチャンクをまだ
 150                                                   -- 讀み終へてゐない
 151                                                   do let (_, input') = B.splitAt (fromIntegral
 152                                                                                   $ fromJust remainingM) input
 153                                                          (footerR, input'') = parse chunkFooterP input'
 154
 155                                                      if footerR == Success () then
 156                                                          -- チャンクフッタを正常に讀めた
 157                                                          do writeItr itr itrReqChunkRemaining $ Just 0
 158
 159                                                             return $ observeChunkedRequest itr input''
 160                                                        else
 161                                                          return $ chunkWasMalformed itr
 162                                                 else
 163                                                   -- 次のチャンクを讀み始める
 164                                                   seekNextChunk itr input
 165                                          else
 166                                            -- 要求がまだ來ない
 167                                            retry
 168                                   else
 169                                     -- 受信要求が來た
 170                                     do remainingM <- readItr itr itrReqChunkRemaining id
 171                                        if fmap (> 0) remainingM == Just True then
 172                                            -- 現在のチャンクをまだ讀み
 173                                            -- 終へてゐない
 174                                            do let wanted             = fromJust wantedM
 175                                                   remaining          = fromJust remainingM
 176                                                   bytesToRead        = fromIntegral $ min wanted remaining
 177                                                   (chunk, input')    = B.splitAt bytesToRead input
 178                                                   actualReadBytes    = fromIntegral $ B.length chunk
 179                                                   newWanted          = case wanted - actualReadBytes of
 180                                                                          0 -> Nothing
 181                                                                          n -> Just n
 182                                                   newRemaining       = Just $ remaining - actualReadBytes
 183                                                   updateStates
 184                                                       = do writeItr itr itrReqChunkRemaining newRemaining
 185                                                            writeItr itr itrReqBodyWanted newWanted
 186                                                            updateItr itr itrReceivedBody $ flip B.append chunk
 187
 188                                               if newRemaining == Just 0 then
 189                                                   -- チャンクフッタを讀む
 190                                                   case parse chunkFooterP input' of
 191                                                     (Success _, input'')
 192                                                         -> do updateStates
 193                                                               return $ observeChunkedRequest itr input''
 194                                                     _   -> return $ chunkWasMalformed itr
 195                                                 else
 196                                                   -- まだチャンクの終はりに達してゐない
 197                                                   do updateStates
 198                                                      return $ observeChunkedRequest itr input'
 199                                          else
 200                                            -- 次のチャンクを讀み始める
 201                                            seekNextChunk itr input
 202                action
 203
 204       seekNextChunk :: Interaction -> ByteString -> STM (IO ())
 205       seekNextChunk itr input
 206           = {-# SCC "seekNextChunk" #-}
 207             case parse chunkHeaderP input of
 208               -- 最終チャンク (中身が空)
 209               (Success 0, input')
 210                   -> case parse chunkTrailerP input' of
 211                        (Success _, input'')
 212                            -> do writeItr itr itrReqChunkLength $ Nothing
 213                                  writeItr itr itrReqChunkRemaining $ Nothing
 214                                  writeItr itr itrReqChunkIsOver True
 215
 216                                  return $ acceptRequest input''
 217                        _   -> return $ chunkWasMalformed itr
 218               -- 最終でないチャンク
 219               (Success len, input')
 220                   -> do writeItr itr itrReqChunkLength $ Just len
 221                         writeItr itr itrReqChunkRemaining $ Just len
 222
 223                         return $ observeChunkedRequest itr input'
 224               -- チャンクヘッダがをかしい
 225               _   -> return $ chunkWasMalformed itr
 226
 227       chunkWasMalformed :: Interaction -> IO ()
 228       chunkWasMalformed itr
 229           = {-# SCC "chunkWasMalformed" #-}
 230             atomically $ do updateItr itr itrResponse
 231                                           $ \ res -> res {
 232                                                        resStatus = BadRequest
 233                                                      }
 234                             writeItr itr itrWillClose True
 235                             writeItr itr itrState Done
 236                             writeDefaultPage itr
 237                             postprocess itr
 238
 239       observeNonChunkedRequest :: Interaction -> ByteString -> IO ()
 240       observeNonChunkedRequest itr input
 241           = {-# SCC "observeNonChunkedRequest" #-}
 242             do action
 243                    <- atomically $
 244                       do wantedM <- readItr itr itrReqBodyWanted id
 245                          if wantedM == Nothing then
 246                              do wasteAll <- readItr itr itrReqBodyWasteAll id
 247                                 if wasteAll then
 248                                     -- 破棄要求が來た
 249                                     do remainingM <- readItr itr itrReqChunkRemaining id
 250
 251                                        let (_, input') = if remainingM == Nothing then
 252                                                              (B.takeWhile (\ _ -> True) input, B.empty)
 253                                                          else
 254                                                              B.splitAt (fromIntegral $ fromJust remainingM) input
 255
 256                                        writeItr itr itrReqChunkRemaining $ Just 0
 257                                        writeItr itr itrReqChunkIsOver True
 258
 259                                        return $ acceptRequest input'
 260                                   else
 261                                     -- 要求がまだ来ない
 262                                     retry
 263                            else
 264                                -- 受信要求が來た
 265                                do remainingM <- readItr itr itrReqChunkRemaining id
 266
 267                                   let wanted          = fromJust wantedM
 268                                       bytesToRead     = fromIntegral $ maybe wanted (min wanted) remainingM
 269                                       (chunk, input') = B.splitAt bytesToRead input
 270                                       newRemaining    = fmap
 271                                                         (\ x -> x - (fromIntegral $ B.length chunk))
 272                                                         remainingM
 273                                       isOver          = B.length chunk < bytesToRead || newRemaining == Just 0
 274
 275                                   writeItr itr itrReqChunkRemaining newRemaining
 276                                   writeItr itr itrReqChunkIsOver isOver
 277                                   writeItr itr itrReqBodyWanted Nothing
 278                                   writeItr itr itrReceivedBody chunk
 279
 280                                   if isOver then
 281                                       return $ acceptRequest input'
 282                                     else
 283                                       return $ observeNonChunkedRequest itr input'
 284                action
 285
 286       enqueue :: Interaction -> STM ()
 287       enqueue itr = {-# SCC "enqueue" #-}
 288                     do queue <- readTVar tQueue
 289                        writeTVar tQueue (itr <| queue)