+-- #prune
+
+-- |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
-
- , getMethod -- Resource Method
- , getHeader -- String -> Resource (Maybe String)
-
- , foundEntity -- Bool -> String -> ClockTime -> Resource ()
- , foundETag -- Bool -> String -> Resource ()
- , foundTimeStamp -- ClockTime -> Resource ()
- , foundNoEntity -- Maybe String -> Resource ()
-
- , input -- Int -> Resource String
- , inputChunk -- Int -> Resource String
- , inputBS -- Int -> Resource ByteString
- , inputChunkBS -- Int -> Resource ByteString
- , defaultLimit -- Int
-
- , setStatus -- StatusCode -> Resource ()
- , setHeader -- String -> String -> Resource ()
- , redirect -- StatusCode -> URI -> Resource ()
- , setETag -- Bool -> String -> Resource ()
- , setLastModified -- ClockTime -> Resource ()
-
- , output -- String -> Resource ()
- , outputChunk -- String -> Resource ()
- , outputBS -- ByteString -> Resource ()
- , outputChunkBS -- ByteString -> Resource ()
+ (
+ -- * Monad
+ Resource
+
+ -- * Actions
+
+ -- ** Getting request header
+
+ -- |These actions can be computed regardless of the current state,
+ -- and they don't change the state.
+ , getConfig
+ , getRemoteAddr
+ , getRemoteAddr'
+ , getRequest
+ , getMethod
+ , getRequestURI
+ , getResourcePath
+ , getPathInfo
+ , getQueryForm
+ , 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
+ , setLocation
+
+ -- ** 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.Exception
import Control.Monad.Reader
+import Data.Bits
import qualified Data.ByteString.Lazy.Char8 as B
import Data.ByteString.Lazy.Char8 (ByteString)
-import Data.Dynamic
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.RFC1123DateTime
import Network.HTTP.Lucu.Request
import Network.HTTP.Lucu.Response
+import Network.HTTP.Lucu.MIMEType
import Network.HTTP.Lucu.Utils
+import Network.Socket
import Network.URI
-import Prelude hiding (catch)
-import System.IO
-import System.IO.Error hiding (catch)
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
-
-{- /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
- , resGet :: Maybe (Resource ())
- , resHead :: Maybe (Resource ())
- , resPost :: Maybe (Resource ())
- , resPut :: Maybe (Resource ())
- , resDelete :: Maybe (Resource ())
- }
-type ResTree = ResNode -- root だから Map ではない
-type ResSubtree = Map String ResNode
-data ResNode = ResNode (Maybe ResourceDef) ResSubtree
-
-
-mkResTree :: [ ([String], ResourceDef) ] -> ResTree
-mkResTree list = processRoot list
- 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]]
+-- |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 SockAddr of the remote host. If you want a string
+-- representation instead of SockAddr, use 'getRemoteAddr''.
+getRemoteAddr :: Resource SockAddr
+getRemoteAddr = do itr <- ask
+ return $! itrRemoteAddr itr
+
+
+-- |Get the string representation of the address of remote host. If
+-- you want a SockAddr instead of String, use 'getRemoteAddr'.
+getRemoteAddr' :: Resource String
+getRemoteAddr' = do addr <- getRemoteAddr
+ case addr of
+ -- Network.Socket は IPv6 を考慮してゐないやうだ…
+ (SockAddrInet _ v4addr)
+ -> let b1 = (v4addr `shiftR` 24) .&. 0xFF
+ b2 = (v4addr `shiftR` 16) .&. 0xFF
+ b3 = (v4addr `shiftR` 8) .&. 0xFF
+ b4 = v4addr .&. 0xFF
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
- 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
- where
- walkTree :: ResSubtree -> [String] -> Maybe ResourceDef
-
- walkTree subtree (name:[])
- = case M.lookup name subtree of
- Nothing -> Nothing
- Just (ResNode defM _) -> defM
-
- 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
-
-
-runResource :: ResourceDef -> Interaction -> IO ThreadId
-runResource def itr
- = fork
- $ catch ( runReaderT ( do fromMaybe notAllowed rsrc
- driftTo Done
- ) itr
- )
- $ \ exc -> processException (itrConfig itr) exc
- where
- fork :: IO () -> IO ThreadId
- fork = if (resUsesNativeThread def)
- then forkOS
- else forkIO
-
- rsrc :: Maybe (Resource ())
- rsrc = case reqMethod $ fromJust $ itrRequest itr of
- GET -> resGet def
- HEAD -> case resHead def of
- Just r -> Just r
- Nothing -> resGet def
- POST -> resPost def
- PUT -> resPut def
- DELETE -> resDelete def
-
- notAllowed :: Resource ()
- notAllowed = do setStatus MethodNotAllowed
- setHeader "Allow" $ joinWith ", " allowedMethods
-
- allowedMethods :: [String]
- allowedMethods = nub $ foldr (++) [] [ methods resGet ["GET"]
- , methods resHead ["GET", "HEAD"]
- , methods resPost ["POST"]
- , methods resPut ["PUT"]
- , methods resDelete ["DELETE"]
- ]
-
- methods :: (ResourceDef -> Maybe a) -> [String] -> [String]
- methods f xs = case f def of
- Just _ -> xs
- Nothing -> []
-
- processException :: Config -> Exception -> IO ()
- processException conf exc
- = do let abo = case exc of
- ErrorCall msg -> Abortion InternalServerError [] msg
- IOException ioE -> Abortion InternalServerError [] $ formatIOE ioE
- DynException dynE -> case fromDynamic dynE of
- Just (abo :: Abortion) -> abo
- Nothing
- -> Abortion InternalServerError []
- $ show exc
- _ -> Abortion InternalServerError [] $ show exc
- -- まだ DecidingHeader 以前の状態だったら、この途中終了
- -- を應答に反映させる餘地がある。さうでなければ stderr
- -- にでも吐くしか無い。
- state <- atomically $ readItr itr itrState id
- if state <= DecidingHeader then
- flip runReaderT itr
- $ do setStatus $ aboStatus abo
- -- FIXME: 同じ名前で複數の値があった時は、こ
- -- れではまずいと思ふ。
- mapM_ (\ (name, value) -> setHeader name value) $ aboHeaders abo
- setHeader "Content-Type" "application/xhtml+xml"
- output $ aboPage conf abo
- else
- hPutStrLn stderr $ show abo
-
- flip runReaderT itr $ driftTo Done
+ return $ concat $ intersperse "." $ map show [b1, b2, b3, b4]
+ (SockAddrUnix path)
+ -> return path
- formatIOE :: IOError -> String
- formatIOE ioE = if isUserError ioE then
- ioeGetErrorString ioE
- else
- show ioE
+-- |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
+ req <- liftIO $! atomically $! readItr itr itrRequest fromJust
+ return req
+-- |Get the 'Network.HTTP.Lucu.Request.Method' value of the request.
getMethod :: Resource Method
-getMethod = do itr <- ask
- return $ reqMethod $ fromJust $ itrRequest itr
-
-
+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
+
+-- | Assume the query part of request URI as
+-- application\/x-www-form-urlencoded, and parse it. This action
+-- doesn't parse the request body. See 'inputForm'.
+getQueryForm :: Resource [(String, String)]
+getQueryForm = do reqURI <- getRequestURI
+ return $! parseWWWFormURLEncoded $ uriQuery reqURI
+
+-- |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 actions like 'getContentType' for
+-- every common headers.
getHeader :: String -> Resource (Maybe String)
-getHeader name = do itr <- ask
- return $ H.getHeader name $ fromJust $ itrRequest itr
+getHeader name = name `seq`
+ do req <- getRequest
+ return $! H.getHeader name req
+
+-- |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
+
{- ExaminingRequest 時に使用するアクション群 -}
-foundEntity :: Bool -> String -> ClockTime -> Resource ()
-foundEntity isWeak token timeStamp
- = do driftTo ExaminingRequest
+-- |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
+ = tag `seq` timeStamp `seq`
+ do driftTo ExaminingRequest
method <- getMethod
when (method == GET || method == HEAD)
- $ setHeader' "Last-Modified" $ formatHTTPDateTime timeStamp
- foundETag isWeak token
+ $ setHeader' "Last-Modified" $! formatHTTPDateTime timeStamp
+ when (method == POST)
+ $ abort InternalServerError []
+ (Just "Illegal computation of foundEntity for POST request.")
+ foundETag tag
driftTo GettingBody
-
-foundETag :: Bool -> String -> Resource ()
-foundETag isWeak token
- = do driftTo ExaminingRequest
-
- let tag = mkETag isWeak token
+-- |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
+ = tag `seq`
+ do driftTo ExaminingRequest
method <- getMethod
when (method == GET || method == HEAD)
- $ setHeader' "ETag" $ show tag
+ $ 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"
-- 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 [] ("The entity tag doesn't match: " ++ list)
- _ -> abort BadRequest [] ("Unparsable If-Match: " ++ fromJust ifMatch)
+ $ 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
ifNoneMatch <- getHeader "If-None-Match"
case ifNoneMatch of
Nothing -> return ()
- Just "*" -> abort statusForNoneMatch [] ("The entity tag matches: *")
+ Just "*" -> abort statusForNoneMatch [] $! Just ("The entity tag matches: *")
Just list -> case parseStr eTagListP list of
(Success tags, _)
-> when (any (== tag) tags)
- $ abort statusForNoneMatch [] ("The entity tag matches: " ++ list)
- _ -> abort BadRequest [] ("Unparsable If-None-Match: " ++ list)
+ $ 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
+ = timeStamp `seq`
+ do driftTo ExaminingRequest
method <- getMethod
when (method == GET || method == HEAD)
- $ setHeader' "Last-Modified" $ formatHTTPDateTime timeStamp
+ $ 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
Just str -> case parseHTTPDateTime str of
Just lastTime
-> when (timeStamp <= lastTime)
- $ abort statusForIfModSince [] ("The entity has not been modified since " ++ str)
+ $ abort statusForIfModSince []
+ $! Just ("The entity has not been modified since " ++ str)
Nothing
-> return () -- 不正な時刻は無視
Nothing -> return ()
Just str -> case parseHTTPDateTime str of
Just lastTime
-> when (timeStamp > lastTime)
- $ abort PreconditionFailed [] ("The entity has not been modified since " ++ str)
+ $ 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@ tells 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, POST or DELETE request,
+-- 'foundNoEntity' always aborts with status \"404 Not Found\".
foundNoEntity :: Maybe String -> Resource ()
foundNoEntity msgM
- = do driftTo ExaminingRequest
-
- let msg = fromMaybe "The requested entity was not found in this server." msgM
+ = msgM `seq`
+ do driftTo ExaminingRequest
method <- getMethod
when (method /= PUT)
- $ abort NotFound [] msg
+ $ 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 [] msg
+ $ abort PreconditionFailed [] msgM
driftTo GettingBody
{- GettingBody 時に使用するアクション群 -}
+-- | Computation of @'input' limit@ attempts to read the request body
+-- up to @limit@ bytes, and then make the 'Resource' transit to
+-- /Deciding Header/ state. When the actual size of body is larger
+-- than @limit@ bytes, computation of 'Resource' immediately aborts
+-- with status \"413 Request Entity Too Large\". When the request has
+-- no body, 'input' returns an empty string.
+--
+-- @limit@ may be less than or equal to zero. In this case, the
+-- default limitation value
+-- ('Network.HTTP.Lucu.Config.cnfMaxEntityLength') is used. See
+-- 'defaultLimit'.
+--
+-- Note that 'inputBS' is more efficient than 'input' so you should
+-- use it whenever possible.
input :: Int -> Resource String
-input limit = inputBS limit >>= return . B.unpack
+input limit = limit `seq`
+ 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。
+-- | This is mostly the same as 'input' but is more
+-- efficient. 'inputBS' returns a lazy ByteString but it's not really
+-- lazy: reading from the socket just happens at the computation of
+-- 'inputBS', not at the lazy evaluation of the ByteString. The same
+-- goes for 'inputChunkBS'.
inputBS :: Int -> Resource ByteString
inputBS limit
- = do driftTo GettingBody
+ = limit `seq`
+ do driftTo GettingBody
itr <- ask
- hasBody <- liftIO $ atomically $ readItr itr itrRequestHasBody id
+ hasBody <- liftIO $! atomically $! readItr itr itrRequestHasBody id
chunk <- if hasBody then
askForInput itr
else
where
askForInput :: Interaction -> Resource ByteString
askForInput itr
- = do let defaultLimit = cnfMaxEntityLength $ itrConfig itr
+ = itr `seq`
+ do let defaultLimit = cnfMaxEntityLength $ itrConfig itr
actualLimit = if limit <= 0 then
defaultLimit
else
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
+ 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
- -- 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
+ 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
+ -- 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 []
- ("Request body must be smaller than "
- ++ show lim ++ " bytes.")
+ tooLarge lim = lim `seq`
+ abortSTM RequestEntityTooLarge []
+ $! Just ("Request body must be smaller than "
+ ++ show lim ++ " bytes.")
-
+-- | Computation of @'inputChunk' limit@ attempts to read a part of
+-- request body up to @limit@ bytes. You can read any large request by
+-- repeating computation of this action. When you've read all the
+-- request body, 'inputChunk' returns an empty string and then make
+-- the 'Resource' transit to /Deciding Header/ state.
+--
+-- @limit@ may be less than or equal to zero. In this case, the
+-- default limitation value
+-- ('Network.HTTP.Lucu.Config.cnfMaxEntityLength') is used. See
+-- 'defaultLimit'.
+--
+-- Note that 'inputChunkBS' is more efficient than 'inputChunk' so you
+-- should use it whenever possible.
inputChunk :: Int -> Resource String
-inputChunk limit = inputChunkBS limit >>= return . B.unpack
+inputChunk limit = limit `seq`
+ 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。
+-- | This is mostly the same as 'inputChunk' but is more
+-- efficient. See 'inputBS'.
inputChunkBS :: Int -> Resource ByteString
inputChunkBS limit
- = do driftTo GettingBody
+ = limit `seq`
+ do driftTo GettingBody
itr <- ask
hasBody <- liftIO $ atomically $ readItr itr itrRequestHasBody id
chunk <- if hasBody then
where
askForInput :: Interaction -> Resource ByteString
askForInput itr
- = do let defaultLimit = cnfMaxEntityLength $ itrConfig itr
+ = itr `seq`
+ do let defaultLimit = cnfMaxEntityLength $! itrConfig itr
actualLimit = if limit < 0 then
defaultLimit
else
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
+ 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
+ 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。
$ driftTo DecidingHeader
return chunk
+-- | Computation of @'inputForm' limit@ attempts to read the request
+-- body with 'input' and parse it as
+-- application\/x-www-form-urlencoded. If the request header
+-- \"Content-Type\" is not application\/x-www-form-urlencoded,
+-- 'inputForm' makes 'Resource' abort with status \"415 Unsupported
+-- Media Type\". If the request has no \"Content-Type\", it aborts
+-- with \"400 Bad Request\".
+--
+-- This action should also support multipart\/form-data somehow, but
+-- it is not (yet) done.
+inputForm :: Int -> Resource [(String, String)]
+inputForm limit
+ = limit `seq`
+ 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 $ parseWWWFormURLEncoded src
+
+ readMultipartFormData -- FIXME: 未對應
+ = abort UnsupportedMediaType []
+ (Just $! "Sorry, inputForm does not currently support multipart/form-data.")
+-- | This is just a constant -1. It's better to say @'input'
+-- 'defaultLimit'@ than to say @'input' (-1)@ but these are exactly
+-- the same.
defaultLimit :: Int
defaultLimit = (-1)
{- DecidingHeader 時に使用するアクション群 -}
+-- | Set the response status code. If you omit to compute this action,
+-- the status code will be defaulted to \"200 OK\".
setStatus :: StatusCode -> Resource ()
setStatus code
- = do driftTo DecidingHeader
+ = code `seq`
+ do driftTo DecidingHeader
itr <- ask
- liftIO $ atomically $ updateItr itr itrResponse
- $ \ resM -> case resM of
- Nothing -> Just $ Response {
- resVersion = HttpVersion 1 1
- , resStatus = code
- , resHeaders = []
- }
- Just res -> Just $ res {
- resStatus = code
- }
-
-
+ 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 actions like 'setContentType'
+-- for every common headers.
+--
+-- Some important headers (especially \"Content-Length\" and
+-- \"Transfer-Encoding\") may be silently dropped or overwritten by
+-- the system not to corrupt the interaction with client at the
+-- viewpoint of HTTP protocol layer. For instance, if we are keeping
+-- the connection alive, without this process it causes a catastrophe
+-- to send a header \"Content-Length: 10\" and actually send a body of
+-- 20 bytes long. In this case the client shall only accept the first
+-- 10 bytes of response body and thinks that the residual 10 bytes is
+-- a part of header of the next response.
setHeader :: String -> String -> Resource ()
setHeader name value
- = driftTo DecidingHeader >> setHeader' name value
+ = name `seq` value `seq`
+ driftTo DecidingHeader >> setHeader' name value
-setHeader' :: String -> String -> Resource()
+setHeader' :: String -> String -> Resource ()
setHeader' name value
- = do itr <- ask
- liftIO $ atomically $ updateItr itr itrResponse
- $ \ resM -> case resM of
- Nothing -> Just $ Response {
- resVersion = HttpVersion 1 1
- , resStatus = Ok
- , resHeaders = [ (name, value) ]
- }
- Just res -> Just $ H.setHeader name value res
-
-
+ = name `seq` value `seq`
+ do itr <- ask
+ liftIO $ atomically
+ $ updateItr itr itrResponse
+ $ H.setHeader name value
+
+-- | Computation of @'redirect' code uri@ sets the response status to
+-- @code@ and \"Location\" header to @uri@. @code@ must satisfy
+-- 'Network.HTTP.Lucu.Response.isRedirection' or it causes an error.
redirect :: StatusCode -> URI -> Resource ()
redirect code uri
- = do when (code == NotModified || not (isRedirection code))
+ = code `seq` uri `seq`
+ do when (code == NotModified || not (isRedirection code))
$ abort InternalServerError []
- $ "Attempted to redirect with status " ++ show code
+ $! Just ("Attempted to redirect with status " ++ show code)
setStatus code
- setHeader "Location" (uriToString id uri $ "")
-
+ setLocation uri
+{-# INLINE redirect #-}
-setETag :: Bool -> String -> Resource ()
-setETag isWeak token
- = setHeader "ETag" $ show $ mkETag isWeak token
+-- | Computation of @'setContentType' mType@ sets the response header
+-- \"Content-Type\" to @mType@.
+setContentType :: MIMEType -> Resource ()
+setContentType mType
+ = setHeader "Content-Type" $! show mType
-setLastModified :: ClockTime -> Resource ()
-setLastModified lastmod
- = setHeader "Last-Modified" $ formatHTTPDateTime lastmod
+-- | Computation of @'setLocation' uri@ sets the response header
+-- \"Location\" to @uri@.
+setLocation :: URI -> Resource ()
+setLocation uri
+ = setHeader "Location" $ uriToString id uri $ ""
{- DecidingBody 時に使用するアクション群 -}
+-- | Computation of @'output' str@ writes @str@ as a response body,
+-- and then make the 'Resource' transit to /Done/ state. It is safe to
+-- apply 'output' to an infinite string, such as a lazy stream of
+-- \/dev\/random.
+--
+-- Note that 'outputBS' is more efficient than 'output' so you should
+-- use it whenever possible.
output :: String -> Resource ()
-output = outputBS . B.pack
-
+output str = outputBS $! B.pack str
+{-# INLINE output #-}
+-- | This is mostly the same as 'output' but is more efficient.
outputBS :: ByteString -> Resource ()
outputBS str = do outputChunkBS str
driftTo Done
-
-
+{-# INLINE outputBS #-}
+
+-- | Computation of @'outputChunk' str@ writes @str@ as a part of
+-- response body. You can compute this action multiple times to write
+-- a body little at a time. It is safe to apply 'outputChunk' to an
+-- infinite string.
+--
+-- Note that 'outputChunkBS' is more efficient than 'outputChunk' so
+-- you should use it whenever possible.
outputChunk :: String -> Resource ()
-outputChunk = outputChunkBS . B.pack
-
+outputChunk str = outputChunkBS $! B.pack str
+{-# INLINE outputChunk #-}
+-- | This is mostly the same as 'outputChunk' but is more efficient.
outputChunkBS :: ByteString -> Resource ()
-outputChunkBS str = do driftTo DecidingBody
- itr <- ask
- liftIO $ atomically $
- do updateItr itr itrBodyToSend (flip B.append str)
- unless (B.null str)
- $ writeItr itr itrBodyIsNull False
+outputChunkBS str
+ = str `seq`
+ 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
+ {- 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。 -}
+ 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
{-
[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。Content-Type も變はる。但し(デフォルトのまま)Status が 200 OK
- だった場合は、補完の代はりに 204 No Content に變へる。
+ る。
-}
driftTo :: InteractionState -> Resource ()
driftTo newState
- = do itr <- ask
+ = newState `seq`
+ do itr <- ask
liftIO $ atomically $ do oldState <- readItr itr itrState id
if newState < oldState then
throwStateError oldState newState
drift itr _ Done
= do bodyIsNull <- readItr itr itrBodyIsNull id
when bodyIsNull
- $ do status <- readStatus itr
- if status == Ok then
- do updateItrF itr itrResponse
- $ \ res -> res { resStatus = NoContent }
- updateItrF itr itrResponse
- $ H.deleteHeader "Content-Type"
- updateItrF itr itrResponse
- $ H.deleteHeader "ETag"
- updateItrF itr itrResponse
- $ H.deleteHeader "Last-Modified"
- else
- writeDefaultPage itr
-
+ $ writeDefaultPage itr
drift _ _ _
= return ()
-
-
- readStatus :: Interaction -> STM StatusCode
- readStatus itr = readItr itr itrResponse (resStatus . fromJust)
\ No newline at end of file