-{-# OPTIONS_HADDOCK prune #-}
+{-# LANGUAGE
+ DoAndIfThenElse
+ , OverloadedStrings
+ , RecordWildCards
+ , UnicodeSyntax
+ #-}
-- | Repository of the resources in httpd.
module Network.HTTP.Lucu.Resource.Tree
- ( ResourceDef(..)
- , emptyResource
-
- , ResTree
+ ( ResTree
, FallbackHandler
- , mkResTree -- [ ([String], ResourceDef) ] -> ResTree
-
- , 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
-import qualified Data.ByteString.Char8 as C8
-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.Headers (emptyHeaders, 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 hiding (path)
-import System.IO
-import Prelude hiding (catch)
-
+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 somewhere in the resource tree. The
--- Lucu httpd first search for a resource in the tree, and then call
+-- 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 'Prelude.Nothing', the httpd responds with 404
--- Not Found.
-type FallbackHandler = [String] -> 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
--- 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。
-
--- | 'ResourceDef' is basically a set of
--- 'Network.HTTP.Lucu.Resource.Resource' monads for each HTTP methods.
-data ResourceDef = ResourceDef {
- -- |Whether to run a 'Network.HTTP.Lucu.Resource.Resource' on a
- -- native thread (spawned by 'Control.Concurrent.forkOS') or to
- -- run it on a user thread (spanwed by
- -- 'Control.Concurrent.forkIO'). Generally you don't need to set
- -- this field to 'Prelude.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
- -- resources are like CGI scripts.
- , 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.
- --
- -- 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 ()))
- }
-
--- |'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
- }
+-- 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 'ResourceDef'.
+-- to 'Resource'.
newtype ResTree = ResTree ResNode -- root だから Map ではない
-type ResSubtree = Map String ResNode
-data ResNode = ResNode (Maybe ResourceDef) ResSubtree
+type ResSubtree = Map ByteString ResNode
+data ResNode = ResNode (Maybe Resource) ResSubtree
-- |'mkResTree' converts a list of @(path, def)@ to a 'ResTree' e.g.
--
-- , ([\"unistd\"], 'Network.HTTP.Lucu.StaticFile.staticFile' \"\/usr\/include\/unistd.h\") -- \/unistd
-- ]
-- @
-mkResTree :: [ ([String], ResourceDef) ] -> ResTree
-mkResTree = processRoot . mapFirst canonicalisePath
+--
+-- 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
- mapFirst :: (a -> a') -> [(a, b)] -> [(a', b)]
- mapFirst f = map (\ (a, b) -> (f a, b))
+ canonicalisePath ∷ [ByteString] → [ByteString]
+ canonicalisePath = filter ((¬) ∘ BS.null)
- canonicalisePath :: [String] -> [String]
- canonicalisePath = filter (\ x -> x /= "")
-
- processRoot :: [ ([String], ResourceDef) ] -> ResTree
+ 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
in
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
-- No resources are defined
-- There is a resource here.
ResNode (Just $ last defs) children
children = processNonRoot [(path, def)
- | (_:path, def) <- list]
+ | (_:path, def) ← list]
in
subtree
-
-findResource :: ResTree -> [FallbackHandler] -> URI -> IO (Maybe ([String], ResourceDef))
+findResource ∷ ResTree
+ → [FallbackHandler]
+ → URI
+ → IO (Maybe ([ByteString], Resource))
findResource (ResTree (ResNode rootDefM subtree)) fbs uri
- = do let pathStr = uriPath uri
- path = [unEscapeString x | x <- splitBy (== '/') pathStr, x /= ""]
- haveGreedyRoot = case rootDefM of
- Just def -> resIsGreedy def
- Nothing -> False
- foundInTree = if haveGreedyRoot || null path then
- do def <- rootDefM
+ = 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 []
+ walkTree subtree path (∅)
if isJust foundInTree then
return foundInTree
- else
+ else
fallback path fbs
where
- walkTree :: ResSubtree -> [String] -> [String] -> Maybe ([String], ResourceDef)
+ walkTree ∷ ResSubtree
+ → [ByteString]
+ → Seq ByteString
+ → Maybe ([ByteString], Resource)
walkTree _ [] _
= error "Internal error: should not reach here."
walkTree tree (name:[]) soFar
- = case M.lookup name tree of
- Nothing -> Nothing
- Just (ResNode defM _) -> do def <- defM
- return (soFar ++ [name], def)
+ = do ResNode defM _ ← M.lookup name tree
+ def ← defM
+ return (toList $ soFar ⊳ name, def)
walkTree tree (x:xs) soFar
- = case M.lookup x tree 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])
-
- fallback :: [String] -> [FallbackHandler] -> IO (Maybe ([String], ResourceDef))
+ = 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
+ 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 def itr
- = def `seq` itr `seq`
- fork
- $! catch ( runRes ( do req <- getRequest
- fromMaybe notAllowed $ rsrc req
- driftTo Done
- ) itr
- )
- processException
- where
- fork :: IO () -> IO ThreadId
- fork = if resUsesNativeThread def
- then forkOS
- else forkIO
-
- 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
- _ -> undefined
-
- notAllowed :: Resource ()
- notAllowed = do setStatus MethodNotAllowed
- setHeader (C8.pack "Allow") (C8.pack $ joinWith ", " allowedMethods)
-
- allowedMethods :: [String]
- allowedMethods = nub $ concat [ 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 -> []
-
- toAbortion :: SomeException -> Abortion
- toAbortion e = case fromException e of
- Just abortion -> abortion
- Nothing -> Abortion InternalServerError emptyHeaders (Just (show e))
-
- processException :: SomeException -> IO ()
- processException exc
- = do let abo = toAbortion exc
- conf = itrConfig 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
- reqM <- atomically $ readItr itr itrRequest id
- res <- atomically $ readItr itr itrResponse id
- if state <= DecidingHeader then
- flip runRes itr
- $ do setStatus $ aboStatus abo
- mapM_ (uncurry setHeader) $ fromHeaders $ aboHeaders abo
- output $ abortPage conf reqM res abo
- else
- when (cnfDumpTooLateAbortionToStderr $ itrConfig itr)
- $ hPutStrLn stderr $ show abo
-
- flip runRes itr $ driftTo Done
+ Just def → return $ Just ([], def)
+ Nothing → fallback path xs
projects / Lucu.git / blobdiff