--- #prune
+{-# LANGUAGE
+ DoAndIfThenElse
+ , OverloadedStrings
+ , RecordWildCards
+ , UnicodeSyntax
+ #-}
-- | Repository of the resources in httpd.
module Network.HTTP.Lucu.Resource.Tree
( ResourceDef(..)
+ , emptyResource
+
, ResTree
- , mkResTree -- [ ([String], ResourceDef) ] -> ResTree
+ , FallbackHandler
+
+ , mkResTree
- , findResource -- ResTree -> URI -> Maybe ([String], ResourceDef)
- , runResource -- ResourceDef -> Interaction -> IO ThreadId
+ , findResource
+ , runResource
)
where
-
+import Control.Arrow
+import Control.Applicative
+import Data.Ascii (Ascii)
+import qualified Data.Ascii as A
import Control.Concurrent
import Control.Concurrent.STM
import Control.Exception
-import Control.Monad.Reader
-import Data.Dynamic
+import Control.Monad
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.Text.Lazy.Encoding as LT
import Data.List
import qualified Data.Map as M
import Data.Map (Map)
import Data.Maybe
+import Data.Monoid.Unicode
import Network.HTTP.Lucu.Abortion
import Network.HTTP.Lucu.Config
-import Network.HTTP.Lucu.MIMEType
+import Network.HTTP.Lucu.Headers (fromHeaders)
import Network.HTTP.Lucu.Request
import Network.HTTP.Lucu.Resource
import Network.HTTP.Lucu.Response
import Network.HTTP.Lucu.Interaction
import Network.HTTP.Lucu.Utils
-import Network.URI
+import Network.URI hiding (path)
import System.IO
-import System.IO.Error hiding (catch)
import Prelude hiding (catch)
+import Prelude.Unicode
+
+
+-- |'FallbackHandler' is an extra resource handler for resources which
+-- can't be statically located anywhere in the resource tree. The Lucu
+-- httpd first searches for a resource in the tree, and then calls
+-- fallback handlers to ask them for a resource. If all of the
+-- handlers returned 'Nothing', the httpd responds with 404 Not Found.
+type FallbackHandler = [Text] → IO (Maybe ResourceDef)
-- "/aaa/bbb/ccc" にアクセスされた時、もし "/aaa/bbb" に貪欲なリソース
-- "/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。
--- | 'ResourceDef' is basically a set of
--- 'Network.HTTP.Lucu.Resource.Resource' monads for each HTTP methods.
+-- | 'ResourceDef' is basically a set of 'Resource' monads for each
+-- HTTP methods.
data ResourceDef = ResourceDef {
- -- | Whether to run a 'Network.HTTP.Lucu.Resource.Resource' on a
- -- native thread (spawned using @forkOS@) or to run it on a user
- -- thread (spanwed using @forkIO@). Generally you don't
- resUsesNativeThread :: !Bool
+ -- |Whether to run a 'Resource' on a native thread (spawned by
+ -- 'forkOS') or to run it on a user thread (spanwed by
+ -- 'forkIO'). Generally you don't need to set this field to
+ -- 'True'.
+ resUsesNativeThread ∷ !Bool
-- | Whether to be greedy or not.
--
-- Say a client is trying to access \/aaa\/bbb\/ccc. If there is a
-- greedy resource at \/aaa\/bbb, it is always chosen even if
-- there is another resource at \/aaa\/bbb\/ccc. If the resource
-- at \/aaa\/bbb is not greedy, it is just ignored. Greedy
- -- resource is like a CGI script.
- , resIsGreedy :: !Bool
- -- | A 'Network.HTTP.Lucu.Resource.Resource' to be run when a GET
- -- request comes for the resource path. If 'resGet' is Nothing,
- -- the system responds \"405 Method Not Allowed\" for GET
- -- requests.
+ -- resources are like CGI scripts.
+ , resIsGreedy ∷ !Bool
+ -- | A 'Resource' to be run when a GET request comes for the
+ -- resource path. If 'resGet' is Nothing, the system responds
+ -- \"405 Method Not Allowed\" for GET requests.
--
-- It also runs for HEAD request if the 'resHead' is Nothing. In
- -- this case 'Network.HTTP.Lucu.Resource.output' and such like
- -- don't actually write a response body.
- , resGet :: !(Maybe (Resource ()))
- -- | A 'Network.HTTP.Lucu.Resource.Resource' to be run when a HEAD
- -- request comes for the resource path. If 'resHead' is Nothing,
- -- the system runs 'resGet' instead. If 'resGet' is also Nothing,
- -- the system responds \"405 Method Not Allowed\" for HEAD
- -- requests.
- , resHead :: !(Maybe (Resource ()))
- -- | A 'Network.HTTP.Lucu.Resource.Resource' to be run when a POST
- -- request comes for the resource path. If 'resPost' is Nothing,
- -- the system responds \"405 Method Not Allowed\" for POST
- -- requests.
- , resPost :: !(Maybe (Resource ()))
- -- | A 'Network.HTTP.Lucu.Resource.Resource' to be run when a PUT
- -- request comes for the resource path. If 'resPut' is Nothing,
- -- the system responds \"405 Method Not Allowed\" for PUT
- -- requests.
- , resPut :: !(Maybe (Resource ()))
- -- | A 'Network.HTTP.Lucu.Resource.Resource' to be run when a
- -- DELETE request comes for the resource path. If 'resDelete' is
- -- Nothing, the system responds \"405 Method Not Allowed\" for
- -- DELETE requests.
- , resDelete :: !(Maybe (Resource ()))
+ -- this case 'output' and such like don't actually write a
+ -- response body.
+ , resGet ∷ !(Maybe (Resource ()))
+ -- | A 'Resource' to be run when a HEAD request comes for the
+ -- resource path. If 'resHead' is Nothing, the system runs
+ -- 'resGet' instead. If 'resGet' is also Nothing, the system
+ -- responds \"405 Method Not Allowed\" for HEAD requests.
+ , resHead ∷ !(Maybe (Resource ()))
+ -- | A 'Resource' to be run when a POST request comes for the
+ -- resource path. If 'resPost' is Nothing, the system responds
+ -- \"405 Method Not Allowed\" for POST requests.
+ , resPost ∷ !(Maybe (Resource ()))
+ -- | A 'Resource' to be run when a PUT request comes for the
+ -- resource path. If 'resPut' is Nothing, the system responds
+ -- \"405 Method Not Allowed\" for PUT requests.
+ , resPut ∷ !(Maybe (Resource ()))
+ -- | A 'Resource' to be run when a DELETE request comes for the
+ -- resource path. If 'resDelete' is Nothing, the system responds
+ -- \"405 Method Not Allowed\" for DELETE requests.
+ , resDelete ∷ !(Maybe (Resource ()))
}
--- | 'ResTree' is an opaque structure which is a map from resource
--- path to 'ResourceDef'.
-type ResTree = ResNode -- root だから Map ではない
-type ResSubtree = Map String ResNode
-data ResNode = ResNode !(Maybe ResourceDef) !ResSubtree
+-- |'emptyResource' is a resource definition with no actual
+-- handlers. You can construct a 'ResourceDef' by selectively
+-- overriding 'emptyResource'. It is defined as follows:
+--
+-- @
+-- emptyResource = ResourceDef {
+-- resUsesNativeThread = False
+-- , resIsGreedy = False
+-- , resGet = Nothing
+-- , resHead = Nothing
+-- , resPost = Nothing
+-- , resPut = Nothing
+-- , resDelete = Nothing
+-- }
+-- @
+emptyResource ∷ ResourceDef
+emptyResource = ResourceDef {
+ resUsesNativeThread = False
+ , resIsGreedy = False
+ , resGet = Nothing
+ , resHead = Nothing
+ , resPost = Nothing
+ , resPut = Nothing
+ , resDelete = Nothing
+ }
+
+-- |'ResTree' is an opaque structure which is a map from resource path
+-- to 'ResourceDef'.
+newtype ResTree = ResTree ResNode -- root だから Map ではない
+type ResSubtree = Map Text ResNode
+data ResNode = ResNode (Maybe ResourceDef) ResSubtree
--- | 'mkResTree' converts a list of @(path, def)@ to a 'ResTree' e.g.
+-- |'mkResTree' converts a list of @(path, def)@ to a 'ResTree' e.g.
--
-- @
-- mkResTree [ ([] , 'Network.HTTP.Lucu.StaticFile.staticFile' \"\/usr\/include\/stdio.h\" ) -- \/
-- , ([\"unistd\"], 'Network.HTTP.Lucu.StaticFile.staticFile' \"\/usr\/include\/unistd.h\") -- \/unistd
-- ]
-- @
-mkResTree :: [ ([String], ResourceDef) ] -> ResTree
-mkResTree list = list `seq` processRoot list
+mkResTree ∷ [ ([Text], ResourceDef) ] → ResTree
+mkResTree = processRoot ∘ map (first canonicalisePath)
where
- processRoot :: [ ([String], ResourceDef) ] -> ResTree
+ canonicalisePath ∷ [Text] → [Text]
+ canonicalisePath = filter (≢ "")
+
+ processRoot ∷ [ ([Text], ResourceDef) ] → ResTree
processRoot list
- = let (roots, nonRoots) = partition (\ (path, _) -> path == []) list
+ = let (roots, nonRoots) = partition (\(path, _) → null 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
+ -- The root has no resources. Maybe there's one at
+ -- somewhere like "/foo".
+ ResTree (ResNode Nothing children)
else
- -- "/" がある。
+ -- There is a root resource.
let (_, def) = last roots
in
- ResNode (Just def) children
+ ResTree (ResNode (Just def) children)
- processNonRoot :: [ ([String], ResourceDef) ] -> ResSubtree
+ processNonRoot ∷ [ ([Text], 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]]
+ | 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。
+ -- No resources are defined
+ -- here. Maybe there's one at
+ -- somewhere below this node.
ResNode Nothing children
else
- -- この位置にリソースがある。
+ -- There is a resource here.
ResNode (Just $ last defs) children
children = processNonRoot [(path, def)
- | (_:path, def) <- list, not (null path)]
+ | (_:path, def) ← list]
in
subtree
-
-findResource :: ResTree -> URI -> Maybe ([String], ResourceDef)
-findResource (ResNode rootDefM subtree) uri
- = let pathStr = uriPath uri
- path = [x | x <- splitBy (== '/') pathStr, x /= ""]
- in
- if null path then
- do def <- rootDefM
- return (path, def)
- else
- walkTree subtree path []
+findResource ∷ ResTree → [FallbackHandler] → URI → IO (Maybe ([Text], ResourceDef))
+findResource (ResTree (ResNode rootDefM subtree)) fbs uri
+ = do let path = splitPathInfo uri
+ hasGreedyRoot = maybe False resIsGreedy rootDefM
+ foundInTree = if hasGreedyRoot ∨ null path then
+ do def ← rootDefM
+ return ([], def)
+ else
+ walkTree subtree path []
+ if isJust foundInTree then
+ return foundInTree
+ else
+ fallback path fbs
where
- walkTree :: ResSubtree -> [String] -> [String] -> Maybe ([String], ResourceDef)
-
- walkTree subtree (name:[]) soFar
- = case M.lookup name subtree of
- Nothing -> Nothing
- Just (ResNode defM _) -> do def <- defM
- return (soFar ++ [name], def)
-
- walkTree subtree (x:xs) soFar
- = case M.lookup x subtree of
- Nothing -> Nothing
- Just (ResNode defM children) -> case defM of
- Just (ResourceDef { resIsGreedy = True })
- -> do def <- defM
- return (soFar ++ [x], def)
- _ -> walkTree children xs (soFar ++ [x])
-
-
-runResource :: ResourceDef -> Interaction -> IO ThreadId
-runResource def itr
- = def `seq` itr `seq`
- fork
- $! catch ( runReaderT ( do req <- getRequest
- fromMaybe notAllowed $ rsrc req
- driftTo Done
- ) itr
- )
- $ \ exc -> processException exc
+ walkTree ∷ ResSubtree → [Text] → [Text] → Maybe ([Text], ResourceDef)
+
+ walkTree _ [] _
+ = error "Internal error: should not reach here."
+
+ walkTree tree (name:[]) soFar
+ = do ResNode defM _ ← M.lookup name tree
+ def ← defM
+ return (soFar ⧺ [name], def)
+
+ walkTree tree (x:xs) soFar
+ = do ResNode defM sub ← M.lookup x tree
+ case defM of
+ Just (ResourceDef { resIsGreedy = True })
+ → do def ← defM
+ return (soFar ⧺ [x], def)
+ _ → walkTree sub xs (soFar ⧺ [x])
+
+ fallback ∷ [Text] → [FallbackHandler] → IO (Maybe ([Text], ResourceDef))
+ fallback _ [] = return Nothing
+ fallback path (x:xs) = do m ← x path
+ case m of
+ Just def → return $ Just ([], def)
+ Nothing → fallback path xs
+
+
+runResource ∷ ResourceDef → Interaction → IO ThreadId
+runResource (ResourceDef {..}) itr@(Interaction {..})
+ = fork $ run `catch` processException
where
- fork :: IO () -> IO ThreadId
- fork = if (resUsesNativeThread def)
- then forkOS
- else forkIO
+ fork ∷ IO () → IO ThreadId
+ fork | resUsesNativeThread = forkOS
+ | otherwise = forkIO
+
+ run ∷ IO ()
+ run = flip runRes itr $
+ do req ← getRequest
+ fromMaybe notAllowed $ rsrc req
+ driftTo Done
- rsrc :: Request -> Maybe (Resource ())
+ rsrc ∷ Request → Maybe (Resource ())
rsrc req
= case reqMethod req 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 :: Exception -> IO ()
+ GET → resGet
+ HEAD → case resHead of
+ Just r → Just r
+ Nothing → resGet
+ POST → resPost
+ PUT → resPut
+ DELETE → resDelete
+ _ → error $ "Unknown request method: " ⧺ show (reqMethod req)
+
+ notAllowed ∷ Resource ()
+ notAllowed
+ = setStatus MethodNotAllowed
+ *>
+ (setHeader "Allow" $ A.fromAsciiBuilder
+ $ joinWith ", "
+ $ map A.toAsciiBuilder allowedMethods)
+
+ allowedMethods ∷ [Ascii]
+ allowedMethods = nub $ concat [ methods resGet ["GET"]
+ , methods resHead ["GET", "HEAD"]
+ , methods resPost ["POST"]
+ , methods resPut ["PUT"]
+ , methods resDelete ["DELETE"]
+ ]
+
+ methods ∷ Maybe a → [Ascii] → [Ascii]
+ methods m xs
+ | isJust m = xs
+ | otherwise = []
+
+ toAbortion ∷ SomeException → Abortion
+ toAbortion e
+ = case fromException e of
+ Just abortion → abortion
+ Nothing → Abortion InternalServerError (∅) (Just $ T.pack $ show e)
+
+ processException ∷ SomeException → IO ()
processException exc
- = do let abo = case exc of
- ErrorCall msg -> Abortion InternalServerError [] $ Just msg
- IOException ioE -> Abortion InternalServerError [] $ Just $ formatIOE ioE
- DynException dynE -> case fromDynamic dynE of
- Just (abo :: Abortion) -> abo
- Nothing
- -> Abortion InternalServerError []
- $ Just $ show exc
- _ -> Abortion InternalServerError [] $ Just $ show exc
- conf = itrConfig itr
+ = do let abo = toAbortion 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
- reqM <- atomically $ readItr itr itrRequest id
- res <- atomically $ readItr itr itrResponse 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
- output $ abortPage conf reqM res abo
- else
- when (cnfDumpTooLateAbortionToStderr $ itrConfig itr)
- $ hPutStrLn stderr $ show abo
-
- flip runReaderT itr $ driftTo Done
-
- formatIOE :: IOError -> String
- formatIOE ioE = if isUserError ioE then
- ioeGetErrorString ioE
- else
- show ioE
+ state ← atomically $ readTVar itrState
+ res ← atomically $ readTVar itrResponse
+ if state ≤ DecidingHeader then
+ flip runRes itr $
+ do setStatus $ aboStatus abo
+ mapM_ (uncurry setHeader) $ fromHeaders $ aboHeaders abo
+ output $ LT.encodeUtf8 $ abortPage itrConfig itrRequest res abo
+ else
+ when (cnfDumpTooLateAbortionToStderr itrConfig)
+ $ hPutStrLn stderr $ show abo
+ runRes (driftTo Done) itr
projects / Lucu.git / blobdiff