@@ -1,10 +1,12 @@
1{-# LANGUAGE AllowAmbiguousTypes #-}
1{-# LANGUAGE AllowAmbiguousTypes #-}
2{-# LANGUAGE ConstraintKinds #-}
2{-# LANGUAGE ConstraintKinds #-}
3{-# LANGUAGE DataKinds #-}
4{-# LANGUAGE DataKinds #-}
4{-# LANGUAGE DeriveDataTypeable #-}
5{-# LANGUAGE DeriveDataTypeable #-}
5{-# LANGUAGE FlexibleContexts #-}
6{-# LANGUAGE FlexibleContexts #-}
6{-# LANGUAGE FlexibleInstances #-}
7{-# LANGUAGE FlexibleInstances #-}
7{-# LANGUAGE InstanceSigs #-}
8{-# LANGUAGE InstanceSigs #-}
9+{-# LANGUAGE LambdaCase #-}
8{-# LANGUAGE MultiParamTypeClasses #-}
10{-# LANGUAGE MultiParamTypeClasses #-}
9{-# LANGUAGE OverloadedStrings #-}
11{-# LANGUAGE OverloadedStrings #-}
10{-# LANGUAGE PolyKinds #-}
12{-# LANGUAGE PolyKinds #-}
@@ -34,9 +36,10 @@ module Servant.Server.Internal
34import Control.Monad
36import Control.Monad
35 (join, when)
37 (join, when)
36import Control.Monad.Trans
38import Control.Monad.Trans
37− (liftIO)
39+ (liftIO, lift)
38import Control.Monad.Trans.Resource
40import Control.Monad.Trans.Resource
39− (runResourceT)
41+ (runResourceT, ReleaseKey)
40import qualified Data.ByteString as B
43import qualified Data.ByteString as B
41import qualified Data.ByteString.Builder as BB
44import qualified Data.ByteString.Builder as BB
42import qualified Data.ByteString.Char8 as BC8
45import qualified Data.ByteString.Char8 as BC8
@@ -63,7 +66,7 @@ import Network.HTTP.Types hiding
63import Network.Socket
66import Network.Socket
64 (SockAddr)
67 (SockAddr)
65import Network.Wai
68import Network.Wai
66− (Application, Request, httpVersion, isSecure, lazyRequestBody,
69+ (Application, Request, Response, ResponseReceived, httpVersion, isSecure, lazyRequestBody,
67 queryString, remoteHost, getRequestBodyChunk, requestHeaders,
70 queryString, remoteHost, getRequestBodyChunk, requestHeaders,
68 requestMethod, responseLBS, responseStream, vault)
71 requestMethod, responseLBS, responseStream, vault)
69import Prelude ()
72import Prelude ()
@@ -73,10 +76,10 @@ import Servant.API
73 CaptureAll, Description, EmptyAPI, Fragment,
76 CaptureAll, Description, EmptyAPI, Fragment,
74 FramingRender (..), FramingUnrender (..), FromSourceIO (..),
77 FramingRender (..), FramingUnrender (..), FromSourceIO (..),
75 Header', If, IsSecure (..), NoContentVerb, QueryFlag,
78 Header', If, IsSecure (..), NoContentVerb, QueryFlag,
76− QueryParam', QueryParams, Raw, ReflectMethod (reflectMethod),
79+ QueryParam', QueryParams, Raw, RawM, ReflectMethod (reflectMethod),
77 RemoteHost, ReqBody', SBool (..), SBoolI (..), SourceIO,
80 RemoteHost, ReqBody', SBool (..), SBoolI (..), SourceIO,
78 Stream, StreamBody', Summary, ToSourceIO (..), Vault, Verb,
81 Stream, StreamBody', Summary, ToSourceIO (..), Vault, Verb,
79− WithNamedContext, NamedRoutes)
82+ WithNamedContext, WithResource, NamedRoutes)
80import Servant.API.Generic (GenericMode(..), ToServant, ToServantApi, GServantProduct, toServant, fromServant)
83import Servant.API.Generic (GenericMode(..), ToServant, ToServantApi, GServantProduct, toServant, fromServant)
81import Servant.API.ContentTypes
84import Servant.API.ContentTypes
82 (AcceptHeader (..), AllCTRender (..), AllCTUnrender (..),
85 (AcceptHeader (..), AllCTRender (..), AllCTUnrender (..),
@@ -94,6 +97,8 @@ import Servant.API.TypeErrors
94import Web.HttpApiData
97import Web.HttpApiData
95 (FromHttpApiData, parseHeader, parseQueryParam, parseUrlPiece,
98 (FromHttpApiData, parseHeader, parseQueryParam, parseUrlPiece,
96 parseUrlPieces)
99 parseUrlPieces)
98import Servant.Server.Internal.BasicAuth
103import Servant.Server.Internal.BasicAuth
99import Servant.Server.Internal.Context
104import Servant.Server.Internal.Context
@@ -112,6 +117,10 @@ import Servant.API.TypeLevel
112 (AtLeastOneFragment, FragmentUnique)
117 (AtLeastOneFragment, FragmentUnique)
114class HasServer api context where
119class HasServer api context where
120+ -- | The type of a server for this API, given a monad to run effects in.
122+ -- Note that the result kind is @*@, so it is /not/ a monad transformer, unlike
123+ -- what the @T@ in the name might suggest.
115 type ServerT api (m :: * -> *) :: *
124 type ServerT api (m :: * -> *) :: *
@@ -241,6 +250,42 @@ instance (KnownSymbol capture, FromHttpApiData a, Typeable a
241 formatError = urlParseErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
250 formatError = urlParseErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
242 hint = CaptureHint (T.pack $ symbolVal $ Proxy @capture) (typeRep (Proxy :: Proxy [a]))
251 hint = CaptureHint (T.pack $ symbolVal $ Proxy @capture) (typeRep (Proxy :: Proxy [a]))
253+-- | If you use 'WithResource' in one of the endpoints for your API Servant
254+-- will provide the handler for this endpoint an argument of the specified type.
255+-- The lifespan of this resource will be automatically managed by Servant. This
256+-- resource will be created before the handler starts and it will be destoyed
257+-- after it ends. A new resource is created for each request to the endpoint.
259+-- The creation and destruction are done using a 'Data.Acquire.Acquire'
260+-- provided via server 'Context'.
264+-- > type MyApi = WithResource Handle :> "writeToFile" :> Post '[JSON] NoContent
266+-- > server :: Server MyApi
267+-- > server = writeToFile
268+-- > where writeToFile :: (ReleaseKey, Handle) -> Handler NoContent
269+-- > writeToFile (_, h) = hPutStrLn h "message"
271+-- In addition to the resource, the handler will also receive a 'ReleaseKey'
272+-- which can be used to deallocate the resource before the end of the request
275+instance (HasServer api ctx, HasContextEntry ctx (Acquire a))
276+ => HasServer (WithResource a :> api) ctx where
278+ type ServerT (WithResource a :> api) m = (ReleaseKey, a) -> ServerT api m
280+ hoistServerWithContext _ pc nt s = hoistServerWithContext (Proxy @api) pc nt . s
282+ route Proxy context d = route (Proxy @api) context (d `addParameterCheck` allocateResource)
284+ allocateResource :: DelayedIO (ReleaseKey, a)
285+ allocateResource = DelayedIO $ lift $ allocateAcquire (getContextEntry context)
244allowedMethodHead :: Method -> Request -> Bool
289allowedMethodHead :: Method -> Request -> Bool
245allowedMethodHead method request = method == methodGet && requestMethod request == methodHead
290allowedMethodHead method request = method == methodGet && requestMethod request == methodHead
@@ -608,6 +653,35 @@ instance HasServer Raw context where
608 Fail a -> respond $ Fail a
653 Fail a -> respond $ Fail a
609 FailFatal e -> respond $ FailFatal e
654 FailFatal e -> respond $ FailFatal e
656+-- | Just pass the request to the underlying application and serve its response.
660+-- > type MyApi = "images" :> Raw
662+-- > server :: Server MyApi
663+-- > server = serveDirectory "/var/www/images"
664+instance HasServer RawM context where
665+ type ServerT RawM m = Request -> (Response -> IO ResponseReceived) -> m ResponseReceived
670+ -> Delayed env (Request -> (Response -> IO ResponseReceived) -> Handler ResponseReceived) -> Router env
671+ route _ _ handleDelayed = RawRouter $ \env request respond -> runResourceT $ do
672+ routeResult <- runDelayed handleDelayed env request
673+ let respond' = liftIO . respond
674+ liftIO $ case routeResult of
675+ Route handler -> runHandler (handler request (respond . Route)) >>=
677+ Left e -> respond' $ FailFatal e
679+ Fail e -> respond' $ Fail e
680+ FailFatal e -> respond' $ FailFatal e
682+ hoistServerWithContext _ _ f srvM = \req respond -> f (srvM req respond)
611-- | If you use 'ReqBody' in one of the endpoints for your API,
685-- | If you use 'ReqBody' in one of the endpoints for your API,
612-- this automatically requires your server-side handler to be a function
686-- this automatically requires your server-side handler to be a function
613-- that takes an argument of the type specified by 'ReqBody'.
687-- that takes an argument of the type specified by 'ReqBody'.
@@ -821,7 +895,11 @@ instance (HasContextEntry context (NamedContext name subContext), HasServer subA
821-------------------------------------------------------------------------------
895-------------------------------------------------------------------------------
823-- Erroring instance for 'HasServer' when a combinator is not fully applied
897-- Erroring instance for 'HasServer' when a combinator is not fully applied
898+instance TypeError (PartialApplication
899+#if __GLASGOW_HASKELL__ >= 904
900+ @(Type -> [Type] -> Constraint)
824−instance TypeError (PartialApplication HasServer arr) => HasServer ((arr :: a -> b) :> sub) context
902+ HasServer arr) => HasServer ((arr :: a -> b) :> sub) context
826 type ServerT (arr :> sub) _ = TypeError (PartialApplication (HasServer :: * -> [*] -> Constraint) arr)
904 type ServerT (arr :> sub) _ = TypeError (PartialApplication (HasServer :: * -> [*] -> Constraint) arr)
827 route = error "unreachable"
905 route = error "unreachable"
@@ -865,7 +943,11 @@ type HasServerArrowTypeError a b =
865-- XXX: This omits the @context@ parameter, e.g.:
943-- XXX: This omits the @context@ parameter, e.g.:
867-- "There is no instance for HasServer (Bool :> …)". Do we care ?
945-- "There is no instance for HasServer (Bool :> …)". Do we care ?
868−instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub HasServer ty) => HasServer (ty :> sub) context
946+instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub
947+#if __GLASGOW_HASKELL__ >= 904
948+ @(Type -> [Type] -> Constraint)
950+ HasServer ty) => HasServer (ty :> sub) context
870instance {-# OVERLAPPABLE #-} TypeError (NoInstanceFor (HasServer api context)) => HasServer api context
952instance {-# OVERLAPPABLE #-} TypeError (NoInstanceFor (HasServer api context)) => HasServer api context