+{-# LANGUAGE
+ DoAndIfThenElse
+ , OverloadedStrings
+ , RecordWildCards
+ , UnicodeSyntax
+ #-}
+
+-- | Repository of the resources in httpd.
module Network.HTTP.Lucu.Resource.Tree
- ( ResourceDef(..)
- , ResTree
- , mkResTree -- [ ([String], ResourceDef) ] -> ResTree
+ ( ResTree
+ , FallbackHandler
- , findResource -- ResTree -> URI -> Maybe ([String], ResourceDef)
- , runResource -- ResourceDef -> Interaction -> IO ThreadId
+ , mkResTree
+ , findResource
)
where
-
-import Control.Concurrent
-import Control.Concurrent.STM
-import Control.Exception
-import Control.Monad.Reader
-import Data.Dynamic
-import Data.List
+import Control.Arrow
+import Data.ByteString (ByteString)
+import qualified Data.ByteString as BS
+import Control.Monad
+import Data.Foldable
+import Data.List
import qualified Data.Map as M
-import Data.Map (Map)
-import Data.Maybe
-import Network.HTTP.Lucu.Abortion
-import Network.HTTP.Lucu.Config
-import Network.HTTP.Lucu.MIMEType
-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 System.IO
-import System.IO.Error hiding (catch)
-import Prelude hiding (catch)
-
-
--- "/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
+import Data.Map (Map)
+import Data.Maybe
+import Data.Monoid.Unicode
+import Data.Sequence (Seq)
+import Network.HTTP.Lucu.Resource.Internal
+import Network.HTTP.Lucu.Utils
+import Network.URI hiding (path)
+import System.IO
+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 = [ByteString] → IO (Maybe Resource)
+
+-- |'ResTree' is an opaque structure which is a map from resource path
+-- to 'Resource'.
+newtype ResTree = ResTree ResNode -- root だから Map ではない
+type ResSubtree = Map ByteString ResNode
+data ResNode = ResNode (Maybe Resource) ResSubtree
+
+-- |'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
+-- ]
+-- @
+--
+-- Note that path components are always represented as octet streams
+-- in this system. Lucu automatically decodes percent-encoded URIs but
+-- has no involvement in character encodings such as UTF-8, since RFC
+-- 2616 (HTTP/1.1) says nothing about character encodings to be used
+-- in \"http\" and \"https\" URI schemas.
+mkResTree ∷ [ ([ByteString], Resource) ] → ResTree
+mkResTree = processRoot ∘ map (first canonicalisePath)
where
- processRoot :: [ ([String], ResourceDef) ] -> ResTree
+ canonicalisePath ∷ [ByteString] → [ByteString]
+ canonicalisePath = filter ((¬) ∘ BS.null)
+
+ processRoot ∷ [ ([ByteString], Resource) ] → 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 ∷ [ ([ByteString], Resource) ] → 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 []
- 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
- = fork
- $ catch ( runReaderT ( do fromMaybe notAllowed rsrc
- driftTo Done
- ) itr
- )
- $ \ exc -> processException exc
+findResource ∷ ResTree
+ → [FallbackHandler]
+ → URI
+ → IO (Maybe ([ByteString], Resource))
+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
- 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 :: Exception -> 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
- reqM = itrRequest itr
- -- 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
- resM <- 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
- setContentType ("application" </> "xhtml+xml")
- output $ abortPage conf reqM resM abo
- else
- hPutStrLn stderr $ show abo
-
- flip runReaderT itr $ driftTo Done
-
- formatIOE :: IOError -> String
- formatIOE ioE = if isUserError ioE then
- ioeGetErrorString ioE
- else
- show ioE
+ walkTree ∷ ResSubtree
+ → [ByteString]
+ → Seq ByteString
+ → Maybe ([ByteString], Resource)
+
+ walkTree _ [] _
+ = error "Internal error: should not reach here."
+
+ walkTree tree (name:[]) soFar
+ = do ResNode defM _ ← M.lookup name tree
+ def ← defM
+ return (toList $ soFar ⊳ name, def)
+
+ walkTree tree (x:xs) soFar
+ = do ResNode defM sub ← M.lookup x tree
+ case defM of
+ Just (Resource { resIsGreedy = True })
+ → do def ← defM
+ return (toList $ soFar ⊳ x, def)
+ _ → walkTree sub xs (soFar ⊳ x)
+
+ fallback ∷ [ByteString]
+ → [FallbackHandler]
+ → IO (Maybe ([ByteString], Resource))
+ fallback _ [] = return Nothing
+ fallback path (x:xs) = do m ← x path
+ case m of
+ Just def → return $ Just ([], def)
+ Nothing → fallback path xs
projects / Lucu.git / blobdiff