X-Git-Url: http://git.cielonegro.org/gitweb.cgi?a=blobdiff_plain;f=Network%2FHTTP%2FLucu%2FAbortion.hs;h=6c2d14dd8c9e00cb09923df93b2097975d736ac7;hb=1f0a19c;hp=b9e4b116250cedee3692aedb9a082ece6d812420;hpb=34b0ad7f2ffc5e7ca67fa3468d01c5551edc8a8b;p=Lucu.git

diff --git a/Network/HTTP/Lucu/Abortion.hs b/Network/HTTP/Lucu/Abortion.hs
index b9e4b11..6c2d14d 100644
--- a/Network/HTTP/Lucu/Abortion.hs
+++ b/Network/HTTP/Lucu/Abortion.hs
@@ -1,75 +1,117 @@
+{-# LANGUAGE
+    Arrows
+  , DeriveDataTypeable
+  , TypeOperators
+  , UnicodeSyntax
+  #-}
+
+-- |Aborting the computation of 'Network.HTTP.Lucu.Resource.Resource'
+-- in any 'Prelude.IO' monads or arrows.
 module Network.HTTP.Lucu.Abortion
     ( Abortion(..)
+
     , abort
+    , abortPurely
     , abortSTM
     , abortA
     , abortPage
     )
     where
-
-import           Control.Arrow
-import           Control.Arrow.ArrowIO
-import           Control.Concurrent.STM
-import           Control.Exception
-import           Control.Monad.Trans
-import           GHC.Conc (unsafeIOToSTM)
-import           Data.Dynamic
-import           Network.HTTP.Lucu.Config
-import           Network.HTTP.Lucu.DefaultPage
-import           Network.HTTP.Lucu.Headers
-import           Network.HTTP.Lucu.HttpVersion
-import           Network.HTTP.Lucu.Request
-import           Network.HTTP.Lucu.Response
-import           System.IO.Unsafe
-import           Text.XML.HXT.Arrow.WriteDocument
-import           Text.XML.HXT.Arrow.XmlArrow
-import           Text.XML.HXT.Arrow.XmlIOStateArrow
-import           Text.XML.HXT.DOM.XmlKeywords
-
+import Blaze.ByteString.Builder (Builder)
+import qualified Blaze.ByteString.Builder.Char.Utf8 as BB
+import Control.Arrow.ArrowIO
+import Control.Arrow.ListArrow
+import Control.Arrow.Unicode
+import Control.Concurrent.STM
+import Control.Exception
+import Control.Monad.Trans
+import Data.Ascii (Ascii, CIAscii)
+import Data.Text (Text)
+import qualified Data.Text as T
+import Data.Typeable
+import Network.HTTP.Lucu.Config
+import Network.HTTP.Lucu.DefaultPage
+import Network.HTTP.Lucu.Headers
+import Network.HTTP.Lucu.Request
+import Network.HTTP.Lucu.Response
+import Prelude.Unicode
+import Text.XML.HXT.Arrow.WriteDocument
+import Text.XML.HXT.Arrow.XmlArrow
+import Text.XML.HXT.Arrow.XmlState
 
 data Abortion = Abortion {
-      aboStatus  :: StatusCode
-    , aboHeaders :: Headers
-    , aboMessage :: Maybe String
-    } deriving (Show, Typeable)
+      aboStatus  ∷ !StatusCode
+    , aboHeaders ∷ !Headers
+    , aboMessage ∷ !(Maybe Text)
+    } deriving (Eq, Show, Typeable)
 
+instance Exception Abortion
 
-abort :: MonadIO m => StatusCode -> [ (String, String) ] -> Maybe String -> m a
-abort status headers msg
-    = let abo = Abortion status headers msg
-          exc = DynException (toDyn abo)
-      in
-        liftIO $ throwIO exc
+-- |Computation of @'abort' status headers msg@ aborts the
+-- 'Network.HTTP.Lucu.Resource.Resource' monad with given status,
+-- additional response headers, and optional message string.
+--
+-- What this really does is to throw an instance of 'Exception'. The
+-- exception will be caught by the Lucu system.
+--
+-- 1. If the 'Network.HTTP.Lucu.Resource.Resource' is in the /Deciding
+--    Header/ or any precedent states, it is possible to use the
+--    @status@ and such like as a HTTP response to be sent to the
+--    client.
+--
+-- 2. Otherwise the HTTP response can't be modified anymore so the
+--    only possible thing the system can do is to dump it to the
+--    stderr. See 'cnfDumpTooLateAbortionToStderr'.
+--
+-- Note that the status code doesn't necessarily have to be an error
+-- code so you can use this action for redirection as well as error
+-- reporting e.g.
+--
+-- > abort MovedPermanently
+-- >       [("Location", "http://example.net/")]
+-- >       (Just "It has been moved to example.net")
+abort ∷ MonadIO m ⇒ StatusCode → [ (CIAscii, Ascii) ] → Maybe Text → m a
+{-# INLINE abort #-}
+abort status headers
+    = liftIO ∘ throwIO ∘ Abortion status (toHeaders headers)
 
+-- |This is similar to 'abort' but computes it with
+-- 'System.IO.Unsafe.unsafePerformIO'.
+abortPurely ∷ StatusCode → [ (CIAscii, Ascii) ] → Maybe Text → a
+{-# INLINE abortPurely #-}
+abortPurely status headers
+    = throw ∘ Abortion status (toHeaders headers)
 
-abortSTM :: StatusCode -> [ (String, String) ] -> Maybe String -> STM a
-abortSTM status headers msg
-    = unsafeIOToSTM $ abort status headers msg
-
-
-abortA :: ArrowIO a => a (StatusCode, ([ (String, String) ], Maybe String)) c
-abortA 
-    = arrIO3 abort
+-- |Computation of @'abortSTM' status headers msg@ just computes
+-- 'abort' in a 'Control.Monad.STM.STM' monad.
+abortSTM ∷ StatusCode → [ (CIAscii, Ascii) ] → Maybe Text → STM a
+{-# INLINE abortSTM #-}
+abortSTM status headers
+    = throwSTM ∘ Abortion status (toHeaders headers)
 
+-- | Computation of @'abortA' -< (status, (headers, msg))@ just
+-- computes 'abort' in an 'Control.Arrow.ArrowIO.ArrowIO'.
+abortA ∷ ArrowIO (⇝) ⇒ (StatusCode, ([ (CIAscii, Ascii) ], Maybe Text)) ⇝ c
+{-# INLINE abortA #-}
+abortA = proc (status, (headers, msg)) →
+         arrIO throwIO ⤙ Abortion status (toHeaders headers) msg
 
 -- aboMessage が Just なら單に mkDefaultPage に渡すだけで良いので樂だが、
 -- Nothing の場合は getDefaultPage を使ってデフォルトのメッセージを得な
 -- ければならない。
-abortPage :: Config -> Maybe Request -> Response -> Abortion -> String
+abortPage ∷ Config → Maybe Request → Response → Abortion → Builder
 abortPage conf reqM res abo
     = case aboMessage abo of
         Just msg
-            -> let [html] = unsafePerformIO 
-                            $ runX ( mkDefaultPage conf (aboStatus abo) (txt msg)
-                                     >>>
-                                     writeDocumentToString [(a_indent, v_1)]
-                                   )
-               in
-                 html
+            → let [html] = runLA ( mkDefaultPage conf (aboStatus abo) (txt $ T.unpack msg)
+                                   ⋙
+                                   writeDocumentToString [ withIndent True ]
+                                 ) ()
+              in
+                BB.fromString html
         Nothing
-            -> let res'  = res { resStatus = aboStatus abo }
-                   res'' = foldl (.) id [setHeader name value
-                                             | (name, value) <- aboHeaders abo]
-                           $ res'
+            → let res'  = res { resStatus = aboStatus abo }
+                  res'' = foldl (∘) id [setHeader name value
+                                            | (name, value) ← fromHeaders $ aboHeaders abo] res'
                in
                  getDefaultPage conf reqM res''