+-- |This is the Resource Monad; monadic actions to define the behavior
+-- of each resources. The 'Resource' Monad is a kind of IO Monad thus
+-- it implements MonadIO class. It is also a state machine.
+--
+-- Request Processing Flow:
+--
+-- 1. A client issues an HTTP request.
+--
+-- 2. If the URI of it matches to any resource, the corresponding
+-- 'Resource' Monad starts running on a newly spawned thread.
+--
+-- 3. The 'Resource' Monad looks at the request header, find (or not
+-- find) an entity, receive the request body (if any), decide the
+-- response header, and decide the response body. This process
+-- will be discussed later.
+--
+-- 4. The 'Resource' Monad and its thread stops running. The client
+-- may or may not be sending us the next request at this point.
+--
+-- 'Resource' Monad takes the following states. The initial state is
+-- /Examining Request/ and the final state is /Done/.
+--
+-- [/Examining Request/] In this state, a 'Resource' looks at the
+-- request header and thinks about an entity for it. If there is a
+-- suitable entity, the 'Resource' tells the system an entity tag
+-- and its last modification time ('foundEntity'). If it found no
+-- entity, it tells the system so ('foundNoEntity'). In case it is
+-- impossible to decide the existence of entity, which is a typical
+-- case for POST requests, 'Resource' does nothing in this state.
+--
+-- [/Getting Body/] A 'Resource' asks the system to receive a
+-- request body from client. Before actually reading from the
+-- socket, the system sends \"100 Continue\" to the client if need
+-- be. When a 'Resource' transits to the next state without
+-- receiving all or part of request body, the system still reads it
+-- and just throws it away.
+--
+-- [/Deciding Header/] A 'Resource' makes a decision of status code
+-- and response header. When it transits to the next state, the
+-- system checks the validness of response header and then write
+-- them to the socket.
+--
+-- [/Deciding Body/] In this state, a 'Resource' asks the system to
+-- write some response body to the socket. When it transits to the
+-- next state without writing any response body, the system
+-- completes it depending on the status code.
+--
+-- [/Done/] Everything is over. A 'Resource' can do nothing for the
+-- HTTP interaction anymore.
+--
+-- Note that the state transition is one-way: for instance, it is an
+-- error to try to read a request body after writing some
+-- response. This limitation is for efficiency. We don't want to read
+-- the entire request before starting 'Resource', nor we don't want to
+-- postpone writing the entire response till the end of 'Resource'
+-- computation.
+
module Network.HTTP.Lucu.Resource
- ( ResourceDef(..)
- , Resource
- , ResTree
- , mkResTree -- [ ([String], ResourceDef) ] -> ResTree
- , findResource -- ResTree -> URI -> Maybe ResourceDef
- , runResource -- ResourceDef -> Interaction -> IO ThreadId
+ (
+ -- * Monad
+ Resource
+
+ -- * Actions
+
+ -- ** Getting request header
+
+ -- |These actions can be computed regardless of the current state,
+ -- and they don't change the state.
+ , getConfig
+ , getRequest
+ , getMethod
+ , getRequestURI
+ , getResourcePath
+ , getPathInfo
+ , getHeader
+ , getAccept
+ , getContentType
+
+ -- ** Finding an entity
+
+ -- |These actions can be computed only in the /Examining Request/
+ -- state. After the computation, the 'Resource' transits to
+ -- /Getting Body/ state.
+ , foundEntity
+ , foundETag
+ , foundTimeStamp
+ , foundNoEntity
+
+ -- ** Getting a request body
+
+ -- |Computation of these actions changes the state to /Getting
+ -- Body/.
+ , input
+ , inputChunk
+ , inputBS
+ , inputChunkBS
+ , inputForm
+ , defaultLimit
+
+ -- ** Setting response headers
+
+ -- |Computation of these actions changes the state to /Deciding
+ -- Header/.
+ , setStatus
+ , setHeader
+ , redirect
+ , setContentType
+
+ -- ** Writing a response body
+
+ -- |Computation of these actions changes the state to /Deciding
+ -- Body/.
+ , output
+ , outputChunk
+ , outputBS
+ , outputChunkBS
+
+ , driftTo
)
where
-import Control.Concurrent
+import Control.Concurrent.STM
import Control.Monad.Reader
import qualified Data.ByteString.Lazy.Char8 as B
import Data.ByteString.Lazy.Char8 (ByteString)
import Data.List
-import qualified Data.Map as M
-import Data.Map (Map)
+import Data.Maybe
+import GHC.Conc (unsafeIOToSTM)
+import Network.HTTP.Lucu.Abortion
+import Network.HTTP.Lucu.Config
+import Network.HTTP.Lucu.DefaultPage
+import Network.HTTP.Lucu.ETag
+import qualified Network.HTTP.Lucu.Headers as H
+import Network.HTTP.Lucu.HttpVersion
import Network.HTTP.Lucu.Interaction
+import Network.HTTP.Lucu.Parser
+import Network.HTTP.Lucu.Postprocess
+import Network.HTTP.Lucu.RFC1123DateTime
+import Network.HTTP.Lucu.Request
+import Network.HTTP.Lucu.Response
+import Network.HTTP.Lucu.MIMEType
import Network.HTTP.Lucu.Utils
import Network.URI
+import System.Time
-
+-- |The 'Resource' monad. /Interaction/ is an internal state thus it
+-- is not exposed to users. This monad implements 'MonadIO' so it can
+-- do any IO actions.
type Resource a = ReaderT Interaction IO a
+-- |Get the 'Network.HTTP.Lucu.Config.Config' value which is used for
+-- the httpd.
+getConfig :: Resource Config
+getConfig = do itr <- ask
+ return $ itrConfig itr
+
+-- |Get the 'Network.HTTP.Lucu.Request.Request' value which represents
+-- the request header. In general you don't have to use this action.
+getRequest :: Resource Request
+getRequest = do itr <- ask
+ return $ fromJust $ itrRequest itr
+
+-- |Get the 'Network.HTTP.Lucu.Request.Method' value of the request.
+getMethod :: Resource Method
+getMethod = do req <- getRequest
+ return $ reqMethod req
+
+-- |Get the URI of the request.
+getRequestURI :: Resource URI
+getRequestURI = do req <- getRequest
+ return $ reqURI req
+
+-- |Get the path of this 'Resource' (to be exact,
+-- 'Network.HTTP.Lucu.Resource.Tree.ResourceDef') in the
+-- 'Network.HTTP.Lucu.Resource.Tree.ResTree'. The result of this
+-- action is the exact path in the tree even if the
+-- 'Network.HTTP.Lucu.Resource.Tree.ResourceDef' is greedy.
+--
+-- Example:
+--
+-- > main = let tree = mkResTree [ (["foo"], resFoo) ]
+-- > in runHttpd defaultConfig tree
+-- >
+-- > resFoo = ResourceDef {
+-- > resIsGreedy = True
+-- > , resGet = Just $ do requestURI <- getRequestURI
+-- > resourcePath <- getResourcePath
+-- > pathInfo <- getPathInfo
+-- > -- uriPath requestURI == "/foo/bar/baz"
+-- > -- resourcePath == ["foo"]
+-- > -- pathInfo == ["bar", "baz"]
+-- > ...
+-- > , ...
+-- > }
+getResourcePath :: Resource [String]
+getResourcePath = do itr <- ask
+ return $ fromJust $ itrResourcePath itr
+
+
+-- |This is an analogy of CGI PATH_INFO. Its result is always @[]@ if
+-- the 'Network.HTTP.Lucu.Resource.Tree.ResourceDef' is not
+-- greedy. See 'getResourcePath'.
+getPathInfo :: Resource [String]
+getPathInfo = do rsrcPath <- getResourcePath
+ reqURI <- getRequestURI
+ let reqPathStr = uriPath reqURI
+ reqPath = [x | x <- splitBy (== '/') reqPathStr, x /= ""]
+ -- rsrcPath と reqPath の共通する先頭部分を reqPath か
+ -- ら全部取り除くと、それは PATH_INFO のやうなものにな
+ -- る。rsrcPath は全部一致してゐるに決まってゐる（でな
+ -- ければこの Resource が撰ばれた筈が無い）ので、
+ -- rsrcPath の長さの分だけ削除すれば良い。
+ return $ drop (length rsrcPath) reqPath
+
+-- |Get a value of given request header. Comparison of header name is
+-- case-insensitive. Note that this action is not intended to be used
+-- so frequently: there should be an action like 'getContentType' for
+-- every common headers.
+getHeader :: String -> Resource (Maybe String)
+getHeader name = do itr <- ask
+ return $ H.getHeader name $ fromJust $ itrRequest itr
+
+-- |Get a list of 'Network.HTTP.Lucu.MIMEType.MIMEType' enumerated on
+-- header \"Accept\".
+getAccept :: Resource [MIMEType]
+getAccept = do accept <- getHeader "Accept"
+ if accept == Nothing then
+ return []
+ else
+ case parseStr mimeTypeListP $ fromJust accept of
+ (Success xs, _) -> return xs
+ _ -> return []
+
+-- |Get the header \"Content-Type\" as
+-- 'Network.HTTP.Lucu.MIMEType.MIMEType'.
+getContentType :: Resource (Maybe MIMEType)
+getContentType = do cType <- getHeader "Content-Type"
+ if cType == Nothing then
+ return Nothing
+ else
+ case parseStr mimeTypeP $ fromJust cType of
+ (Success t, _) -> return $ Just t
+ _ -> return Nothing
+
-{- /aaa/bbb/ccc にアクセスされた時、もし /aaa/bbb に貪欲なリソースがあ
- れば、假に /aaa/bbb/ccc に何らかのリソースがあったとしても必ず
- /aaa/bbb が撰ばれる。/aaa/bbb のリソースが貪欲でなければ、それは無視
- される。 -}
-data ResourceDef = ResourceDef {
- resUsesNativeThread :: Bool
- , resIsGreedy :: Bool
- , resResource :: Resource ()
- }
-type ResTree = ResNode -- root だから Map ではない
-type ResSubtree = Map String ResNode
-data ResNode = ResNode (Maybe ResourceDef) ResSubtree
+{- ExaminingRequest 時に使用するアクション群 -}
-mkResTree :: [ ([String], ResourceDef) ] -> ResTree
-mkResTree list = processRoot list
+-- |Tell the system that the 'Resource' found an entity for the
+-- request URI. If this is a GET or HEAD request, a found entity means
+-- a datum to be replied. If this is a PUT or DELETE request, it means
+-- a datum which was stored for the URI up to now. It is an error to
+-- compute 'foundEntity' if this is a POST request.
+--
+-- Computation of 'foundEntity' performs \"If-Match\" test or
+-- \"If-None-Match\" test if possible. When those tests fail, the
+-- computation of 'Resource' immediately aborts with status \"412
+-- Precondition Failed\" or \"304 Not Modified\" depending on the
+-- situation.
+--
+-- If this is a GET or HEAD request, 'foundEntity' automatically puts
+-- \"ETag\" and \"Last-Modified\" headers into the response.
+foundEntity :: ETag -> ClockTime -> Resource ()
+foundEntity tag timeStamp
+ = do driftTo ExaminingRequest
+
+ method <- getMethod
+ when (method == GET || method == HEAD)
+ $ setHeader' "Last-Modified" $ formatHTTPDateTime timeStamp
+ when (method == POST)
+ $ abort InternalServerError []
+ (Just "Illegal computation of foundEntity for POST request.")
+ foundETag tag
+
+ driftTo GettingBody
+
+-- |Tell the system that the 'Resource' found an entity for the
+-- request URI. The only difference from 'foundEntity' is that
+-- 'foundETag' doesn't (and can't) put \"Last-Modified\" header into
+-- the response.
+--
+-- This action is not preferred. You should use 'foundEntity' when
+-- possible.
+foundETag :: ETag -> Resource ()
+foundETag tag
+ = do driftTo ExaminingRequest
+
+ method <- getMethod
+ when (method == GET || method == HEAD)
+ $ setHeader' "ETag" $ show tag
+ when (method == POST)
+ $ abort InternalServerError []
+ (Just "Illegal computation of foundETag for POST request.")
+
+ -- If-Match があればそれを見る。
+ ifMatch <- getHeader "If-Match"
+ case ifMatch of
+ Nothing -> return ()
+ Just "*" -> return ()
+ Just list -> case parseStr eTagListP list of
+ (Success tags, _)
+ -- tags の中に一致するものが無ければ
+ -- PreconditionFailed で終了。
+ -> when (not $ any (== tag) tags)
+ $ abort PreconditionFailed []
+ $ Just ("The entity tag doesn't match: " ++ list)
+ _ -> abort BadRequest [] $ Just ("Unparsable If-Match: " ++ fromJust ifMatch)
+
+ let statusForNoneMatch = if method == GET || method == HEAD then
+ NotModified
+ else
+ PreconditionFailed
+
+ -- If-None-Match があればそれを見る。
+ ifNoneMatch <- getHeader "If-None-Match"
+ case ifNoneMatch of
+ Nothing -> return ()
+ Just "*" -> abort statusForNoneMatch [] $ Just ("The entity tag matches: *")
+ Just list -> case parseStr eTagListP list of
+ (Success tags, _)
+ -> when (any (== tag) tags)
+ $ abort statusForNoneMatch [] $ Just ("The entity tag matches: " ++ list)
+ _ -> abort BadRequest [] $ Just ("Unparsable If-None-Match: " ++ list)
+
+ driftTo GettingBody
+
+-- |Tell the system that the 'Resource' found an entity for the
+-- request URI. The only difference from 'foundEntity' is that
+-- 'foundTimeStamp' performs \"If-Modified-Since\" test or
+-- \"If-Unmodified-Since\" test instead of \"If-Match\" test or
+-- \"If-None-Match\" test. Be aware that any tests based on last
+-- modification time are unsafe because it is possible to mess up such
+-- tests by modifying the entity twice in a second.
+--
+-- This action is not preferred. You should use 'foundEntity' when
+-- possible.
+foundTimeStamp :: ClockTime -> Resource ()
+foundTimeStamp timeStamp
+ = do driftTo ExaminingRequest
+
+ method <- getMethod
+ when (method == GET || method == HEAD)
+ $ setHeader' "Last-Modified" $ formatHTTPDateTime timeStamp
+ when (method == POST)
+ $ abort InternalServerError []
+ (Just "Illegal computation of foundTimeStamp for POST request.")
+
+ let statusForIfModSince = if method == GET || method == HEAD then
+ NotModified
+ else
+ PreconditionFailed
+
+ -- If-Modified-Since があればそれを見る。
+ ifModSince <- getHeader "If-Modified-Since"
+ case ifModSince of
+ Just str -> case parseHTTPDateTime str of
+ Just lastTime
+ -> when (timeStamp <= lastTime)
+ $ abort statusForIfModSince []
+ $ Just ("The entity has not been modified since " ++ str)
+ Nothing
+ -> return () -- 不正な時刻は無視
+ Nothing -> return ()
+
+ -- If-Unmodified-Since があればそれを見る。
+ ifUnmodSince <- getHeader "If-Unmodified-Since"
+ case ifUnmodSince of
+ Just str -> case parseHTTPDateTime str of
+ Just lastTime
+ -> when (timeStamp > lastTime)
+ $ abort PreconditionFailed []
+ $ Just ("The entity has not been modified since " ++ str)
+ Nothing
+ -> return () -- 不正な時刻は無視
+ Nothing -> return ()
+
+ driftTo GettingBody
+
+-- |Computation of @'foundNoEntity' mStr@ tell the system that the
+-- 'Resource' found no entity for the request URI. @mStr@ is an
+-- optional error message to be replied to the client.
+--
+-- If this is a PUT request, 'foundNoEntity' performs \"If-Match\"
+-- test and aborts with status \"412 Precondition Failed\" when it
+-- failed. If this is a GET, HEAD or DELETE request, 'foundNoEntity'
+-- always aborts with status \"404 Not Found\". It is an error to
+-- compute 'foundNoEntity' if this is a POST request.
+foundNoEntity :: Maybe String -> Resource ()
+foundNoEntity msgM
+ = do driftTo ExaminingRequest
+
+ method <- getMethod
+ when (method == POST)
+ $ abort InternalServerError []
+ (Just "Illegal computation of foundNoEntity for POST request.")
+ when (method /= PUT)
+ $ abort NotFound [] msgM
+
+ -- エンティティが存在しないと云ふ事は、"*" も含めたどのやうな
+ -- If-Match: 條件も滿たさない。
+ ifMatch <- getHeader "If-Match"
+ when (ifMatch /= Nothing)
+ $ abort PreconditionFailed [] msgM
+
+ driftTo GettingBody
+
+
+{- GettingBody 時に使用するアクション群 -}
+
+input :: Int -> Resource String
+input limit = inputBS limit >>= return . B.unpack
+
+
+-- 多くとも limit バイトまでのリクエストボディ全體を受信する。limit が
+-- 零以下なら Config で設定されたデフォルトのボディ長により制限される。
+inputBS :: Int -> Resource ByteString
+inputBS limit
+ = do driftTo GettingBody
+ itr <- ask
+ hasBody <- liftIO $ atomically $ readItr itr itrRequestHasBody id
+ chunk <- if hasBody then
+ askForInput itr
+ else
+ do driftTo DecidingHeader
+ return B.empty
+ return chunk
where
- processRoot :: [ ([String], ResourceDef) ] -> ResTree
- processRoot list
- = let (roots, nonRoots) = partition (\ (path, _) -> path == []) list
- children = processNonRoot nonRoots
- in
- if null roots then
- -- / にリソースが定義されない。/foo とかにはあるかも。
- ResNode Nothing children
- else
- -- / がある。
- let (_, def) = last roots
- in
- ResNode (Just def) children
-
- processNonRoot :: [ ([String], ResourceDef) ] -> ResSubtree
- processNonRoot list
- = let subtree = M.fromList [(name, node name)
- | name <- childNames]
- childNames = [name | (name:_, _) <- list]
- node name = let defs = [def | (path, def) <- list, path == [name]]
- in
- if null defs then
- -- この位置にリソースが定義されない。
- -- もっと下にはあるかも。
- ResNode Nothing children
+ askForInput :: Interaction -> Resource ByteString
+ askForInput itr
+ = do let defaultLimit = cnfMaxEntityLength $ itrConfig itr
+ actualLimit = if limit <= 0 then
+ defaultLimit
+ else
+ limit
+ when (actualLimit <= 0)
+ $ fail ("inputBS: limit must be positive: " ++ show actualLimit)
+ -- Reader にリクエスト
+ liftIO $ atomically
+ $ do chunkLen <- readItr itr itrReqChunkLength id
+ writeItr itr itrWillReceiveBody True
+ if fmap (> actualLimit) chunkLen == Just True then
+ -- 受信前から多過ぎる事が分かってゐる
+ tooLarge actualLimit
+ else
+ writeItr itr itrReqBodyWanted $ Just actualLimit
+ -- 應答を待つ。トランザクションを分けなければ當然デッドロック。
+ chunk <- liftIO $ atomically
+ $ do chunk <- readItr itr itrReceivedBody id
+ chunkIsOver <- readItr itr itrReqChunkIsOver id
+ if B.length chunk < fromIntegral actualLimit then
+ -- 要求された量に滿たなくて、まだ殘り
+ -- があるなら再試行。
+ unless chunkIsOver
+ $ retry
else
- -- この位置にリソースがある。
- ResNode (Just $ last defs) children
- children = processNonRoot [(path, def)
- | (_:path, def) <- list, not (null path)]
- in
- subtree
-
-
-findResource :: ResTree -> URI -> Maybe ResourceDef
-findResource (ResNode rootDefM subtree) uri
- = let pathStr = uriPath uri
- path = [x | x <- splitBy (== '/') pathStr, x /= ""]
- in
- if null path then
- rootDefM
- else
- walkTree subtree path
+ -- 制限値一杯まで讀むやうに指示したの
+ -- にまだ殘ってゐるなら、それは多過ぎ
+ -- る。
+ unless chunkIsOver
+ $ tooLarge actualLimit
+ -- 成功。itr 内にチャンクを置いたままにす
+ -- るとメモリの無駄になるので除去。
+ writeItr itr itrReceivedBody B.empty
+ return chunk
+ driftTo DecidingHeader
+ return chunk
+
+ tooLarge :: Int -> STM ()
+ tooLarge lim = abortSTM RequestEntityTooLarge []
+ $ Just ("Request body must be smaller than "
+ ++ show lim ++ " bytes.")
+
+
+inputChunk :: Int -> Resource String
+inputChunk limit = inputChunkBS limit >>= return . B.unpack
+
+
+-- 多くとも limit バイトまでのリクエストボディの一部を受信する。limit
+-- が 0 以下なら Config で設定されたデフォルトのボディ長により制限され
+-- る。これ以上ボディが殘ってゐなければ空文字列を返す。
+inputChunkBS :: Int -> Resource ByteString
+inputChunkBS limit
+ = do driftTo GettingBody
+ itr <- ask
+ hasBody <- liftIO $ atomically $ readItr itr itrRequestHasBody id
+ chunk <- if hasBody then
+ askForInput itr
+ else
+ do driftTo DecidingHeader
+ return B.empty
+ return chunk
+ where
+ askForInput :: Interaction -> Resource ByteString
+ askForInput itr
+ = do let defaultLimit = cnfMaxEntityLength $ itrConfig itr
+ actualLimit = if limit < 0 then
+ defaultLimit
+ else
+ limit
+ when (actualLimit <= 0)
+ $ fail ("inputChunkBS: limit must be positive: " ++ show actualLimit)
+ -- Reader にリクエスト
+ liftIO $ atomically
+ $ do writeItr itr itrReqBodyWanted $ Just actualLimit
+ writeItr itr itrWillReceiveBody True
+ -- 應答を待つ。トランザクションを分けなければ當然デッドロック。
+ chunk <- liftIO $ atomically
+ $ do chunk <- readItr itr itrReceivedBody id
+ -- 要求された量に滿たなくて、まだ殘りがあ
+ -- るなら再試行。
+ when (B.length chunk < fromIntegral actualLimit)
+ $ do chunkIsOver <- readItr itr itrReqChunkIsOver id
+ unless chunkIsOver
+ $ retry
+ -- 成功
+ writeItr itr itrReceivedBody B.empty
+ return chunk
+ when (B.null chunk)
+ $ driftTo DecidingHeader
+ return chunk
+
+
+-- application/x-www-form-urlencoded または multipart/form-data をパー
+-- スする。もし Content-Type が無かったら BadRequest で終了し、未對應の
+-- タイプであったら UnsupportedMediaType で終了する。
+inputForm :: Int -> Resource [(String, String)]
+inputForm limit
+ = do cTypeM <- getContentType
+ case cTypeM of
+ Nothing
+ -> abort BadRequest [] (Just "Missing Content-Type")
+ Just (MIMEType "application" "x-www-form-urlencoded" _)
+ -> readWWWFormURLEncoded
+ Just (MIMEType "multipart" "form-data" _)
+ -> readMultipartFormData
+ Just cType
+ -> abort UnsupportedMediaType [] (Just $ "Unsupported media type: "
+ ++ show cType)
+ where
+ readWWWFormURLEncoded
+ = do src <- input limit
+ return $ do pairStr <- splitBy (\ c -> c == ';' || c == '&') src
+ let pair = break (== '=') pairStr
+ return ( unEscapeString $ fst pair
+ , unEscapeString $ snd pair
+ )
+ readMultipartFormData -- FIXME: 未對應
+ = abort UnsupportedMediaType []
+ (Just $ "Sorry, inputForm does not currently support multipart/form-data.")
+
+
+defaultLimit :: Int
+defaultLimit = (-1)
+
+
+
+{- DecidingHeader 時に使用するアクション群 -}
+
+setStatus :: StatusCode -> Resource ()
+setStatus code
+ = do driftTo DecidingHeader
+ itr <- ask
+ liftIO $ atomically $ updateItr itr itrResponse
+ $ \ res -> res {
+ resStatus = code
+ }
+
+-- | Set a value of given resource header. Comparison of header name
+-- is case-insensitive. Note that this action is not intended to be
+-- used so frequently: there should be an action like 'setContentType'
+-- for every common headers.
+--
+-- Some important headers (especially \"Content-Length\" and
+-- \"Transfer-Encoding\") may be silently deleted or overwritten by
+-- the system not to corrupt the interaction with client at the
+-- viewpoint of HTTP protocol. For instance, if we are keeping
+-- connection alive, for an obvious reason it causes a catastrophe to
+-- send header \"Content-Length: 10\" and actually sending body of 20
+-- bytes long.
+setHeader :: String -> String -> Resource ()
+setHeader name value
+ = driftTo DecidingHeader >> setHeader' name value
+
+
+setHeader' :: String -> String -> Resource()
+setHeader' name value
+ = do itr <- ask
+ liftIO $ atomically
+ $ updateItr itr itrResponse
+ $ H.setHeader name value
+
+
+redirect :: StatusCode -> URI -> Resource ()
+redirect code uri
+ = do when (code == NotModified || not (isRedirection code))
+ $ abort InternalServerError []
+ $ Just ("Attempted to redirect with status " ++ show code)
+ setStatus code
+ setHeader "Location" (uriToString id uri $ "")
+
+
+setContentType :: MIMEType -> Resource ()
+setContentType mType
+ = setHeader "Content-Type" $ show mType
+
+
+{- DecidingBody 時に使用するアクション群 -}
+
+output :: String -> Resource ()
+output = outputBS . B.pack
+
+
+outputBS :: ByteString -> Resource ()
+outputBS str = do outputChunkBS str
+ driftTo Done
+
+
+outputChunk :: String -> Resource ()
+outputChunk = outputChunkBS . B.pack
+
+
+{- チャンクの大きさは Config で制限されてゐる。もし例へば /dev/zero を
+ B.readFile して作った ByteString をそのまま ResponseWriter に渡した
+ りすると大變な事が起こる。何故なら ResponseWriter は
+ Transfer-Encoding: chunked の時、ヘッダを書く爲にチャンクの大きさを
+ 測るから、その時に起こるであらう事は言ふまでも無い。 -}
+
+outputChunkBS :: ByteString -> Resource ()
+outputChunkBS str
+ = do driftTo DecidingBody
+ itr <- ask
+
+ let limit = cnfMaxOutputChunkLength $ itrConfig itr
+ when (limit <= 0)
+ $ fail ("cnfMaxOutputChunkLength must be positive: "
+ ++ show limit)
+
+ discardBody <- liftIO $ atomically $
+ readItr itr itrWillDiscardBody id
+
+ unless (discardBody)
+ $ sendChunks str limit
+
+ unless (B.null str)
+ $ liftIO $ atomically $
+ writeItr itr itrBodyIsNull False
where
- walkTree :: ResSubtree -> [String] -> Maybe ResourceDef
+ sendChunks :: ByteString -> Int -> Resource ()
+ sendChunks str limit
+ | B.null str = return ()
+ | otherwise = do let (chunk, remaining) = B.splitAt (fromIntegral limit) str
+ itr <- ask
+ liftIO $ atomically $
+ do buf <- readItr itr itrBodyToSend id
+ if B.null buf then
+ -- バッファが消化された
+ writeItr itr itrBodyToSend chunk
+ else
+ -- 消化されるのを待つ
+ retry
+ -- 殘りのチャンクについて繰り返す
+ sendChunks remaining limit
+
+{-
+
+ [GettingBody からそれ以降の状態に遷移する時]
+
+ body を讀み終へてゐなければ、殘りの body を讀み捨てる。
+
- walkTree subtree (name:[])
- = case M.lookup name subtree of
- Nothing -> Nothing
- Just (ResNode defM _) -> defM
+ [DecidingHeader からそれ以降の状態に遷移する時]
- walkTree subtree (x:xs)
- = case M.lookup x subtree of
- Nothing -> Nothing
- Just (ResNode defM children) -> case defM of
- Just (ResourceDef { resIsGreedy = True })
- -> defM
- _ -> walkTree children xs
+ postprocess する。
-runResource :: ResourceDef -> Interaction -> IO ThreadId
-runResource def itr = fork $ runReaderT rsrc itr -- FIXME: 例外をcatch
+ [Done に遷移する時]
+
+ bodyIsNull が False ならば何もしない。True だった場合は出力補完す
+ る。
+
+-}
+
+driftTo :: InteractionState -> Resource ()
+driftTo newState
+ = do itr <- ask
+ liftIO $ atomically $ do oldState <- readItr itr itrState id
+ if newState < oldState then
+ throwStateError oldState newState
+ else
+ do let a = [oldState .. newState]
+ b = tail a
+ c = zip a b
+ mapM_ (uncurry $ drift itr) c
+ writeItr itr itrState newState
where
- fork = if (resUsesNativeThread def)
- then forkOS
- else forkIO
- rsrc = resResource def
\ No newline at end of file
+ throwStateError :: Monad m => InteractionState -> InteractionState -> m a
+
+ throwStateError Done DecidingBody
+ = fail "It makes no sense to output something after finishing to output."
+
+ throwStateError old new
+ = fail ("state error: " ++ show old ++ " ==> " ++ show new)
+
+
+ drift :: Interaction -> InteractionState -> InteractionState -> STM ()
+
+ drift itr GettingBody _
+ = writeItr itr itrReqBodyWasteAll True
+
+ drift itr DecidingHeader _
+ = postprocess itr
+
+ drift itr _ Done
+ = do bodyIsNull <- readItr itr itrBodyIsNull id
+ when bodyIsNull
+ $ writeDefaultPage itr
+
+ drift _ _ _
+ = return ()
projects / Lucu.git / blobdiff