{- | Non monadic low level primitives that implement the MFlow application server. See "MFlow.Form" for the higher level interface that you may use. it implements an scheduler of 'Processable' messages that are served according with the source identification and the verb invoked. The scheduler executed the appropriate workflow (using the workflow package). The workflow will send additional messages to the source and wait for the responses. The diaglog is identified by a 'Token', which is associated to the flow. . The computation state is optionally logged. On timeout, the process is killed. When invoked again, the execution state is recovered as if no interruption took place. There is no asumption about message codification, so instantiations of this scheduler for different infrastructures is possible, including non-Web based ones as long as they support or emulate cookies. "MFlow.Hack" is an instantiation for the Hack interface in a Web context. "MFlow.Wai" is a instantiation for the WAI interface. "MFlow.Forms" implements a monadic type safe interface with composabe widgets and and applicative combinator as well as an higher comunication interface. "MFlow.Forms.XHtml" is an instantiation for the Text.XHtml format "MFlow.Forms.Blaze.Html" is an instantaiation for blaze-html "MFlow.Forms.HSP" is an instantiation for the Haskell Server Pages format There are some @*.All@ packages thant contain a mix of these instantiations. For exmaple, "MFlow.Wai.Blaze.Html.All" includes most of all necessary for using MFlow with Wai and Blaze-html In order to manage resources, there are primitives that kill the process and its state after a timeout. All these details are hidden in the monad of "MFlow.Forms" that provides an higher level interface. Fragment based streaming: 'sendFragment' are provided only at this level. 'stateless' and 'transient' server processeses are also possible. the first are request-response . `transient` processes do not persist after timeout, so they restart anew after a timeout or a crash. -} {-# LANGUAGE DeriveDataTypeable, UndecidableInstances ,ExistentialQuantification ,MultiParamTypeClasses ,FunctionalDependencies ,TypeSynonymInstances ,FlexibleInstances ,FlexibleContexts ,RecordWildCards ,OverloadedStrings ,ScopedTypeVariables #-} module MFlow ( Flow, Params, HttpData(..),Processable(..) , Token(..), ProcList -- * low level comunication primitives. Use `ask` instead ,flushRec, receive, receiveReq, receiveReqTimeout, send, sendFlush, sendFragment , sendEndFragment -- * Flow configuration ,addMessageFlows,getMessageFlows, transient, stateless,anonymous ,noScript,hlog, setNotFoundResponse,getNotFoundResponse, -- * ByteString tags -- | very basic but efficient tag formatting btag, bhtml, bbody,Attribs, addAttrs -- * static files ,setFilesPath -- * internal use ,addTokenToList,deleteTokenInList, msgScheduler,serveFile,newFlow ) where import Control.Concurrent.MVar import Data.IORef import GHC.Conc(unsafeIOToSTM) import Data.Typeable import Data.Maybe(isJust, isNothing, fromMaybe, fromJust) import Data.Char(isSeparator) import Data.List(isPrefixOf,isSuffixOf,isInfixOf, elem , span, (\\)) import Control.Monad(when) import Data.Monoid import Control.Concurrent(forkIO,threadDelay,killThread, myThreadId, ThreadId) import Data.Char(toLower) import Unsafe.Coerce import System.IO.Unsafe import Data.TCache import Data.TCache.DefaultPersistence hiding(Indexable(..)) import Data.TCache.Memoization import Data.ByteString.Lazy.Char8 as B (readFile,ByteString, concat,pack, unpack,empty,append,cons,fromChunks) import Data.ByteString.Lazy.Internal (ByteString(Chunk)) import qualified Data.Map as M import System.IO import System.Time import Control.Workflow import MFlow.Cookies import Control.Monad.Trans import qualified Control.Exception as CE --import Debug.Trace --(!>)= flip trace type Flow= (Token -> Workflow IO ()) data HttpData = HttpData Params [Cookie] ByteString | Error WFErrors ByteString deriving (Typeable, Show) --instance ToHttpData HttpData where -- toHttpData= id -- --instance ToHttpData ByteString where -- toHttpData bs= HttpData [] [] bs instance Monoid HttpData where mempty= HttpData [] [] empty mappend (HttpData h c s) (HttpData h' c' s')= HttpData (h++h') (c++ c') $ mappend s s' -- | List of (wfname, workflow) pairs, to be scheduled depending on the message's pwfname type ProcList = WorkflowList IO Token () data Req = forall a.( Processable a, Typeable a)=> Req a deriving Typeable type Params = [(String,String)] class Processable a where pwfname :: a -> String puser :: a -> String pind :: a -> String getParams :: a -> Params -- getServer ::a -> String -- getPath :: a -> String -- getPort :: a -> Int instance Processable Token where pwfname = twfname puser = tuser pind = tind getParams = tenv instance Processable Req where pwfname (Req x)= pwfname x puser (Req x)= puser x pind (Req x)= pind x getParams (Req x)= getParams x -- getServer (Req x)= getServer x -- getPath (Req x)= getPath x -- getPort (Req x)= getPort x data Resp = Fragm HttpData | EndFragm HttpData | Resp HttpData -- | a Token identifies a flow that handle messages. The scheduler compose a Token with every `Processable` -- message that arrives and send the mesage to the appropriate flow. data Token = Token{twfname,tuser, tind :: String , tenv:: Params, tsendq :: MVar Req, trecq :: MVar Resp} deriving Typeable instance Indexable Token where key (Token w u i _ _ _ )= if u== anonymous then u++ i -- ++ "@" ++ w else u -- ++ "@" ++ w instance Show Token where show t = "Token " ++ key t instance Read Token where readsPrec _ ('T':'o':'k':'e': 'n':' ':str1) | anonymous `isPrefixOf` str1= [(Token w anonymous i [] (newVar 0) (newVar 0), tail str2)] | otherwise = [(Token w ui "0" [] (newVar 0) (newVar 0), tail str2)] where (ui,str')= span(/='@') str1 i = drop (length anonymous) ui (w,str2) = span (not . isSeparator) $ tail str' newVar _= unsafePerformIO $ newEmptyMVar readsPrec _ str= error $ "parse error in Token read from: "++ str instance Serializable Token where serialize = pack . show deserialize= read . unpack iorefqmap= unsafePerformIO . newMVar $ M.empty addTokenToList t@Token{..} = modifyMVar_ iorefqmap $ \ map -> return $ M.insert ( tind ++ twfname ++ tuser ) t map deleteTokenInList t@Token{..} = modifyMVar_ iorefqmap $ \ map -> return $ M.delete (tind ++ twfname ++ tuser) map getToken msg= do qmap <- readMVar iorefqmap let u= puser msg ; w= pwfname msg ; i=pind msg; penv= getParams msg let mqs = M.lookup ( i ++ w ++ u) qmap case mqs of Nothing -> do q <- newEmptyMVar -- `debug` (i++w++u) qr <- newEmptyMVar let token= Token w u i penv q qr addTokenToList token return token Just token-> return token -- | The anonymous user anonymous= "anon#" -- | It is the path of the root flow noScript = "noscript" {- instance (Monad m, Show a) => Traceable (Workflow m a) where debugf iox str = do x <- iox return $ debug x (str++" => Workflow "++ show x) -} -- | send a complete response --send :: Token -> HttpData -> IO() send t@(Token _ _ _ _ _ qresp) msg= do ( putMVar qresp . Resp $ msg ) -- !> ("<<<<< send "++ thread t) sendFlush t msg= flushRec t >> send t msg -- !> "sendFlush " -- | send a response fragment. Useful for streaming. the last packet must sent trough 'send' sendFragment :: Token -> HttpData -> IO() sendFragment (Token _ _ _ _ _ qresp) msg= putMVar qresp . Fragm $ msg {-# DEPRECATED sendEndFragment "use send to end a fragmented response instead" #-} sendEndFragment :: Token -> HttpData -> IO() sendEndFragment (Token _ _ _ _ _ qresp ) msg= putMVar qresp $ EndFragm msg --emptyReceive (Token queue _ _)= emptyQueue queue receive :: Typeable a => Token -> IO a receive t= receiveReq t >>= return . fromReq flushRec t@(Token _ _ _ _ queue _)= do empty <- isEmptyMVar queue when (not empty) $ takeMVar queue >> return () receiveReq :: Token -> IO Req receiveReq t@(Token _ _ _ _ queue _)= readMVar queue -- !> (">>>>>> receive "++ thread t) fromReq :: Typeable a => Req -> a fromReq (Req x) = x' where x'= case cast x of Nothing -> error $ "receive: received type: "++ show (typeOf x) ++ " does not match the desired type:" ++ show (typeOf x') Just y -> y receiveReqTimeout :: Int -> Integer -> Token -> IO Req receiveReqTimeout 0 0 t= receiveReq t receiveReqTimeout time time2 t= let id= keyWF (twfname t) t in withKillTimeout id time time2 (receiveReq t) delMsgHistory t = do let statKey= keyWF (twfname t) t -- !> "wf" --let qnme= keyWF wfname t delWFHistory1 statKey -- `debug` "delWFHistory" -- | executes a simple monadic computation that receive the params and return a response -- -- It is used with `addMessageFlows` -- -- There is a higuer level version @wstateless@ in "MFLow.Forms" stateless :: (Params -> IO HttpData) -> Flow stateless f = transient proc where proc t@(Token _ _ _ _ queue qresp) = loop t queue qresp loop t queue qresp=do req <- takeMVar queue -- !> (">>>>>> stateless " ++ thread t) resp <- f (getParams req) (putMVar qresp $ Resp resp ) -- !> ("<<<<<< stateless " ++thread t) loop t queue qresp -- !> ("enviado stateless " ++ thread t) -- -- | Executes a monadic computation that send and receive messages, but does -- not store its state in permanent storage. The process once stopped, will restart anew -- ---- It is used with `addMessageFlows` `hackMessageFlow` or `waiMessageFlow` transient :: (Token -> IO ()) -> Flow transient f= unsafeIOtoWF . f -- WF(\s -> f t>>= \x-> return (s, x) ) _messageFlows :: MVar (WorkflowList IO Token ()) -- MVar (M.Map String (Token -> Workflow IO ())) _messageFlows= unsafePerformIO $ newMVar emptyFList where emptyFList= M.empty :: WorkflowList IO Token () -- | add a list of flows to be scheduled. Each entry in the list is a pair @(path, flow)@ addMessageFlows wfs= modifyMVar_ _messageFlows(\ms -> return $ M.union ms (M.fromList $ map flt wfs)) where flt ("",f)= (noScript,f) flt e= e -- | return the list of the scheduler getMessageFlows = readMVar _messageFlows --class ToHttpData a where -- toHttpData :: a -> HttpData thread t= show(unsafePerformIO myThreadId) ++ " "++ show (twfname t) --tellToWF :: (Typeable a, Typeable c, Processable a) => Token -> a -> IO c tellToWF t@(Token _ _ _ _ queue qresp ) msg = do putMVar queue (Req msg) -- !> (">>>>> telltowf"++ thread t) m <- takeMVar qresp -- !> ("<<<<<< tellTowf"++ thread t) case m of Resp r -> return r -- !> ("recibido tellTowf"++ thread t) Fragm r -> do result <- getStream r return result where getStream r = do mr <- takeMVar qresp case mr of Fragm h -> do rest <- unsafeInterleaveIO $ getStream h let result= mappend r rest return result EndFragm h -> do let result= mappend r h return result Resp h -> do let result= mappend r h return result --processData t= do -- token <- getToken t -- th <- startMessageFlow (pwfname t) token -- tellToWF token t -- where -- startMessageFlow wfname token = -- forkIO $ do -- r <- start wfname (process mempty) token -- !>( "init wf " ++ wfname) -- case r of -- Left NotFound -> do -- error $ "Not found: " ++ wfname -- deleteTokenInList token -- Left AlreadyRunning -> return () -- !> ("already Running " ++ wfname) -- Left Timeout -> return() -- !> "Timeout in msgScheduler" -- Left (WFException e)-> do -- let user= key token -- print e -- logError user wfname e -- moveState wfname token token{tuser= "error/"++tuser token} -- -- -- process val t= do -- r <- step $ receive t -- let val'= r <> val -- recover <- isInRecover -- when(not recover) . liftIO $ sendFlush t val' -- process val' t -- -- | The scheduler creates a Token with every `Processable` -- message that arrives and send the mesage to the appropriate flow, then waht for the response -- and return it. -- -- It is the core of the application server. "MFLow.Wai" and "MFlow.Hack" use it msgScheduler :: (Typeable a,Processable a) => a -> IO (HttpData, ThreadId) msgScheduler x = do token <- getToken x th <- startMessageFlow (pwfname x) token r <- tellToWF token x -- !> let HttpData _ _ r1=r in unpack r1 return (r,th) where --start the flow if not started yet startMessageFlow wfname token = forkIO $ do wfs <- getMessageFlows r <- startWF wfname token wfs -- !>( "init wf " ++ wfname) case r of Left NotFound -> do sendFlush token =<< serveFile wfname -- sendFlush token (Error NotFound $ "Not found: " <> pack wfname) deleteTokenInList token Left AlreadyRunning -> return () -- !> ("already Running " ++ wfname) Left Timeout -> return() -- !> "Timeout in msgScheduler" Left (WFException e)-> do let user= key token print e logError user wfname e -- moveState wfname token token{tuser= "error/"++tuser token} fresp<- getNotFoundResponse sendFlush token $ HttpData [("Content-Type", "text/html")] [] $ fresp $ case user of "admin" -> pack $ show e _ -> mempty Right _ -> do -- let msg= "finished Flow "++ wfname++ " restarting" -- logError (key token) wfname msg -- startMessageFlow wfname token wfs delMsgHistory token; return () -- !> ("finished " ++ wfname) logError u wf e= do hSeek hlog SeekFromEnd 0 t <- return . calendarTimeToString =<< toCalendarTime =<< getClockTime hPutStrLn hlog (","++show [u, t,wf,e]) >> hFlush hlog logFileName= "errlog" -- | The handler of the error log hlog= unsafePerformIO $ openFile logFileName ReadWriteMode defNotFoundResponse msg= "

Error 404: Page not found or error ocurred:

" <> msg <> "


" <> opts <> "
press here to go home" where paths= Prelude.map B.pack . M.keys $ unsafePerformIO getMessageFlows opts= "options: " <> B.concat (Prelude.map (\s -> " s <>"\">"<> s <>", ") paths) notFoundResponse= unsafePerformIO $ newIORef defNotFoundResponse -- | set the 404 "not found" response setNotFoundResponse f= liftIO $ writeIORef notFoundResponse f getNotFoundResponse= liftIO $ readIORef notFoundResponse -- basic bytestring tags type Attribs= [(String,String)] -- | Writes a XML tag in a ByteString. It is the most basic form of formatting. For -- more sophisticated formatting , use "MFlow.Forms.XHtml" or "MFlow.Forms.HSP". btag :: String -> Attribs -> ByteString -> ByteString btag t rs v= "<" `append` pt `append` attrs rs `append` ">" `append` v `append`"" where pt= pack t attrs []= B.empty attrs rs= pack $ concatMap(\(n,v) -> (' ' : n) ++ "=\"" ++ v++ "\"" ) rs -- | -- > bhtml ats v= btag "html" ats v bhtml :: Attribs -> ByteString -> ByteString bhtml ats v= btag "html" ats v -- | -- > bbody ats v= btag "body" ats v bbody :: Attribs -> ByteString -> ByteString bbody ats v= btag "body" ats v addAttrs :: ByteString -> Attribs -> ByteString addAttrs (Chunk "<" (Chunk tag rest)) rs= Chunk "<"(Chunk tag (pack $ concatMap(\(n,v) -> (' ' : n) ++ "=" ++ v ) rs)) <> rest addAttrs other _ = error $ "addAttrs: byteString is not a tag: " ++ show other --- basic file server ---- -- | Set the path of the files in the web server. The links to the files are relative to it. -- The files are cached (memoized) according with the "Data.TCache" policies in the program space. This avoid the blocking of -- the efficient GHC threads by frequent IO calls.So it enhances the performance -- in the context of heavy concurrence. -- It uses 'Data.TCache.Memoization'. -- The caching-uncaching follows the `setPersist` criteria setFilesPath :: String -> IO () setFilesPath path= writeIORef rfilesPath path rfilesPath= unsafePerformIO $ newIORef "files/" serveFile path'= do when(let hpath= head path' in hpath == '/' || hpath =='\\') $ error noperm when(not(".." `isSuffixOf` path') && ".." `isInfixOf` path') $ error noperm filesPath <- readIORef rfilesPath let path= filesPath ++ path' mr <- cachedByKey path 0 $ (B.readFile path >>= return . Just) `CE.catch` ioerr (return Nothing) case mr of Nothing -> return $ HttpData [setMime "text/plain"] [] $ pack $ "not accessible" Just r -> let ext = reverse . takeWhile (/='.') $ reverse path mmime= lookup (map toLower ext) mimeTable mime = case mmime of Just m -> m ;Nothing -> "application/octet-stream" in return $ HttpData [setMime mime, ("Cache-Control", "max-age=360000")] [] r where noperm= "no permissions" ioerr x= \(e :: CE.IOException) -> x setMime x= ("Content-Type",x) data NFlow= NFlow !Integer deriving (Read, Show, Typeable) instance Serializable NFlow where serialize= B.pack . show deserialize= read . B.unpack instance Indexable NFlow where key _= "Flow" rflow= getDBRef . key $ NFlow undefined newFlow= do TOD t _ <- getClockTime atomically $ do NFlow n <- readDBRef rflow `onNothing` return (NFlow 0) writeDBRef rflow . NFlow $ n+1 return . show $ t + n mimeTable=[ ("html", "text/html"), ("htm", "text/html"), ("txt", "text/plain"), ("hs", "text/plain"), ("lhs", "text/plain"), ("jpeg", "image/jpeg"), ("pdf", "application/pdf"), ("js", "application/x-javascript"), ("gif", "image/gif"), ("bmp", "image/bmp"), ("ico", "image/x-icon"), ("doc", "application/msword"), ("jpg", "image/jpeg"), ("eps", "application/postscript"), ("zip", "application/zip"), ("exe", "application/octet-stream"), ("tif", "image/tiff"), ("tiff", "image/tiff"), ("mov", "video/quicktime"), ("movie", "video/x-sgi-movie"), ("mp2", "video/mpeg"), ("mp3", "audio/mpeg"), ("mpa", "video/mpeg"), ("mpe", "video/mpeg"), ("mpeg", "video/mpeg"), ("mpg", "video/mpeg"), ("mpp", "application/vnd.ms-project"), ("323", "text/h323"), ("*", "application/octet-stream"), ("acx", "application/internet-property-stream"), ("ai", "application/postscript"), ("aif", "audio/x-aiff"), ("aifc", "audio/x-aiff"), ("aiff", "audio/x-aiff"), ("asf", "video/x-ms-asf"), ("asr", "video/x-ms-asf"), ("asx", "video/x-ms-asf"), ("au", "audio/basic"), ("avi", "video/x-msvideo"), ("axs", "application/olescript"), ("bas", "text/plain"), ("bcpio", "application/x-bcpio"), ("bin", "application/octet-stream"), ("c", "text/plain"), ("cat", "application/vnd.ms-pkiseccat"), ("cdf", "application/x-cdf"), ("cdf", "application/x-netcdf"), ("cer", "application/x-x509-ca-cert"), ("class", "application/octet-stream"), ("clp", "application/x-msclip"), ("cmx", "image/x-cmx"), ("cod", "image/cis-cod"), ("cpio", "application/x-cpio"), ("crd", "application/x-mscardfile"), ("crl", "application/pkix-crl"), ("crt", "application/x-x509-ca-cert"), ("csh", "application/x-csh"), ("css", "text/css"), ("dcr", "application/x-director"), ("der", "application/x-x509-ca-cert"), ("dir", "application/x-director"), ("dll", "application/x-msdownload"), ("dms", "application/octet-stream"), ("dot", "application/msword"), ("dvi", "application/x-dvi"), ("dxr", "application/x-director"), ("eps", "application/postscript"), ("etx", "text/x-setext"), ("evy", "application/envoy"), ("fif", "application/fractals"), ("flr", "x-world/x-vrml"), ("gtar", "application/x-gtar"), ("gz", "application/x-gzip"), ("h", "text/plain"), ("hdf", "application/x-hdf"), ("hlp", "application/winhlp"), ("hqx", "application/mac-binhex40"), ("hta", "application/hta"), ("htc", "text/x-component"), ("htt", "text/webviewhtml"), ("ief", "image/ief"), ("iii", "application/x-iphone"), ("ins", "application/x-internet-signup"), ("isp", "application/x-internet-signup"), ("jfif", "image/pipeg"), ("jpe", "image/jpeg"), ("latex", "application/x-latex"), ("lha", "application/octet-stream"), ("lsf", "video/x-la-asf"), ("lsx", "video/x-la-asf"), ("lzh", "application/octet-stream"), ("m13", "application/x-msmediaview"), ("m14", "application/x-msmediaview"), ("m3u", "audio/x-mpegurl"), ("man", "application/x-troff-man"), ("mdb", "application/x-msaccess"), ("me", "application/x-troff-me"), ("mht", "message/rfc822"), ("mhtml", "message/rfc822"), ("mid", "audio/mid"), ("mny", "application/x-msmoney"), ("mpv2", "video/mpeg"), ("ms", "application/x-troff-ms"), ("msg", "application/vnd.ms-outlook"), ("mvb", "application/x-msmediaview"), ("nc", "application/x-netcdf"), ("nws", "message/rfc822"), ("oda", "application/oda"), ("p10", "application/pkcs10"), ("p12", "application/x-pkcs12"), ("p7b", "application/x-pkcs7-certificates"), ("p7c", "application/x-pkcs7-mime"), ("p7m", "application/x-pkcs7-mime"), ("p7r", "application/x-pkcs7-certreqresp"), ("p7s", "application/x-pkcs7-signature"), ("png", "image/png"), ("pbm", "image/x-portable-bitmap"), ("pfx", "application/x-pkcs12"), ("pgm", "image/x-portable-graymap"), ("pko", "application/ynd.ms-pkipko"), ("pma", "application/x-perfmon"), ("pmc", "application/x-perfmon"), ("pml", "application/x-perfmon"), ("pmr", "application/x-perfmon"), ("pmw", "application/x-perfmon"), ("pnm", "image/x-portable-anymap"), ("pot", "application/vnd.ms-powerpoint"), ("ppm", "image/x-portable-pixmap"), ("pps", "application/vnd.ms-powerpoint"), ("ppt", "application/vnd.ms-powerpoint"), ("prf", "application/pics-rules"), ("ps", "application/postscript"), ("pub", "application/x-mspublisher"), ("qt", "video/quicktime"), ("ra", "audio/x-pn-realaudio"), ("ram", "audio/x-pn-realaudio"), ("ras", "image/x-cmu-raster"), ("rgb", "image/x-rgb"), ("rmi", "audio/mid"), ("roff", "application/x-troff"), ("rtf", "application/rtf"), ("rtx", "text/richtext"), ("scd", "application/x-msschedule"), ("sct", "text/scriptlet"), ("setpay", "application/set-payment-initiation"), ("setreg", "application/set-registration-initiation"), ("sh", "application/x-sh"), ("shar", "application/x-shar"), ("sit", "application/x-stuffit"), ("snd", "audio/basic"), ("spc", "application/x-pkcs7-certificates"), ("spl", "application/futuresplash"), ("src", "application/x-wais-source"), ("sst", "application/vnd.ms-pkicertstore"), ("stl", "application/vnd.ms-pkistl"), ("stm", "text/html"), ("sv4cpio", "application/x-sv4cpio"), ("sv4crc", "application/x-sv4crc"), ("svg", "image/svg+xml"), ("swf", "application/x-shockwave-flash"), ("t", "application/x-troff"), ("tar", "application/x-tar"), ("tcl", "application/x-tcl"), ("tex", "application/x-tex"), ("texi", "application/x-texinfo"), ("texinfo", "application/x-texinfo"), ("tgz", "application/x-compressed"), ("tr", "application/x-troff"), ("trm", "application/x-msterminal"), ("tsv", "text/tab-separated-values"), ("uls", "text/iuls"), ("ustar", "application/x-ustar"), ("vcf", "text/x-vcard"), ("vrml", "x-world/x-vrml"), ("wav", "audio/x-wav"), ("wcm", "application/vnd.ms-works"), ("wdb", "application/vnd.ms-works"), ("wks", "application/vnd.ms-works"), ("wmf", "application/x-msmetafile"), ("wps", "application/vnd.ms-works"), ("wri", "application/x-mswrite"), ("wrl", "x-world/x-vrml"), ("wrz", "x-world/x-vrml"), ("xaf", "x-world/x-vrml"), ("xbm", "image/x-xbitmap"), ("xla", "application/vnd.ms-excel"), ("xlc", "application/vnd.ms-excel"), ("xlm", "application/vnd.ms-excel"), ("xls", "application/vnd.ms-excel"), ("xlt", "application/vnd.ms-excel"), ("xlw", "application/vnd.ms-excel"), ("xof", "x-world/x-vrml"), ("xpm", "image/x-xpixmap"), ("xwd", "image/x-xwindowdump"), ("z", "application/x-compress") ]