X-Git-Url: http://git.cielonegro.org/gitweb.cgi?a=blobdiff_plain;f=Network%2FHTTP%2FLucu%2FResource%2FTree.hs;h=06fed17dd13c7d52af6d49e7f65ca3adcc164fb8;hb=f62b6f07bbf1eefcf552163d8f7daa6e0862ed5d;hp=062ffdca9217b5dd5462cf238fdb97e033b01ca7;hpb=c6b11025d1f81c668e9995e856b7bb34175230d3;p=Lucu.git

diff --git a/Network/HTTP/Lucu/Resource/Tree.hs b/Network/HTTP/Lucu/Resource/Tree.hs
index 062ffdc..06fed17 100644
--- a/Network/HTTP/Lucu/Resource/Tree.hs
+++ b/Network/HTTP/Lucu/Resource/Tree.hs
@@ -1,10 +1,14 @@
+{-# OPTIONS_HADDOCK prune #-}
+
+-- | Repository of the resources in httpd.
 module Network.HTTP.Lucu.Resource.Tree
     ( ResourceDef(..)
-    , Resource
     , ResTree
+    , FallbackHandler
+
     , mkResTree    -- [ ([String], ResourceDef) ] -> ResTree
 
-    , findResource -- ResTree -> URI -> Maybe ResourceDef
+    , findResource -- ResTree -> URI -> Maybe ([String], ResourceDef)
     , runResource  -- ResourceDef -> Interaction -> IO ThreadId
     )
     where
@@ -12,45 +16,103 @@ module Network.HTTP.Lucu.Resource.Tree
 import           Control.Concurrent
 import           Control.Concurrent.STM
 import           Control.Exception
-import           Control.Monad.Reader
-import           Data.Dynamic
+import           Control.Monad
+import qualified Data.ByteString.Char8 as C8
 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
+import           Network.URI hiding (path)
 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。 -}
+-- |'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
+-- 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 {
-      resUsesNativeThread :: Bool
-    , resIsGreedy         :: Bool
-    , resGet              :: Maybe (Resource ())
-    , resHead             :: Maybe (Resource ())
-    , resPost             :: Maybe (Resource ())
-    , resPut              :: Maybe (Resource ())
-    , resDelete           :: Maybe (Resource ())
+    -- |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 ()))
     }
-type ResTree    = ResNode -- root だから Map ではない
-type ResSubtree = Map String ResNode
-data ResNode    = ResNode (Maybe ResourceDef) ResSubtree
 
+-- |'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 String ResNode
+data ResNode    = ResNode !(Maybe ResourceDef) !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
+--             ]
+-- @
 mkResTree :: [ ([String], ResourceDef) ] -> ResTree
-mkResTree list = processRoot list
+mkResTree xs = xs `seq` processRoot xs
     where
       processRoot :: [ ([String], ResourceDef) ] -> ResTree
       processRoot list
@@ -58,13 +120,13 @@ mkResTree list = processRoot 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
+                  -- "/" にリソースが定義されない。"/foo" とかにはあるかも。
+                  ResTree (ResNode Nothing children)
               else
-                  -- / がある。
+                  -- "/" がある。
                   let (_, def) = last roots
                   in 
-                    ResNode (Just def) children
+                    ResTree (ResNode (Just def) children)
 
       processNonRoot :: [ ([String], ResourceDef) ] -> ResSubtree
       processNonRoot list
@@ -86,103 +148,115 @@ mkResTree list = processRoot list
               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
+findResource :: ResTree -> [FallbackHandler] -> URI -> IO (Maybe ([String], ResourceDef))
+findResource (ResTree (ResNode rootDefM subtree)) fbs uri
+    = do let pathStr     = uriPath uri
+             path        = [x | x <- splitBy (== '/') pathStr, x /= ""]
+             foundInTree = if null path then
+                               do def <- rootDefM
+                                  return (path, def)
+                           else
+                               walkTree subtree path []
+         if isJust foundInTree then
+             return foundInTree
+           else
+             fallback path fbs
     where
-      walkTree :: ResSubtree -> [String] -> Maybe ResourceDef
+      walkTree :: ResSubtree -> [String] -> [String] -> Maybe ([String], ResourceDef)
+
+      walkTree _ [] _
+          = error "Internal error: should not reach here."
 
-      walkTree subtree (name:[])
-          = case M.lookup name subtree of
+      walkTree tree (name:[]) soFar
+          = case M.lookup name tree of
               Nothing               -> Nothing
-              Just (ResNode defM _) -> defM
+              Just (ResNode defM _) -> do def <- defM
+                                          return (soFar ++ [name], def)
 
-      walkTree subtree (x:xs)
-          = case M.lookup x subtree of
+      walkTree tree (x:xs) soFar
+          = case M.lookup x tree of
               Nothing                      -> Nothing
               Just (ResNode defM children) -> case defM of
                                                 Just (ResourceDef { resIsGreedy = True })
-                                                    -> defM
-                                                _   -> walkTree children xs
+                                                    -> do def <- defM
+                                                          return (soFar ++ [x], def)
+                                                _   -> walkTree children xs (soFar ++ [x])
+
+      fallback :: [String] -> [FallbackHandler] -> IO (Maybe ([String], 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 def itr
-    = fork
-      $ catch ( runReaderT ( do fromMaybe notAllowed rsrc 
-                                driftTo Done
-                           ) itr
-              )
-      $ \ exc -> processException (itrConfig itr) exc
+    = 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)
+      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
+      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 "Allow" $ joinWith ", " allowedMethods
+                      setHeader (C8.pack "Allow") (C8.pack $ joinWith ", " allowedMethods)
 
       allowedMethods :: [String]
-      allowedMethods = nub $ foldr (++) [] [ methods resGet    ["GET"]
-                                           , methods resHead   ["GET", "HEAD"]
-                                           , methods resPost   ["POST"]
-                                           , methods resPut    ["PUT"]
-                                           , methods resDelete ["DELETE"]
-                                           ]
+      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 -> []
 
-      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
+      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 runReaderT itr
+                   flip runRes 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
+                           mapM_ (uncurry setHeader) $ fromHeaders $ aboHeaders abo
+                           output $ abortPage conf reqM res abo
                  else
-                   hPutStrLn stderr $ show abo
-
-               flip runReaderT itr $ driftTo Done
+                   when (cnfDumpTooLateAbortionToStderr $ itrConfig itr)
+                            $ hPutStrLn stderr $ show abo
 
-      formatIOE :: IOError -> String
-      formatIOE ioE = if isUserError ioE then
-                          ioeGetErrorString ioE
-                      else
-                          show ioE
+               flip runRes itr $ driftTo Done