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Merge pull request #959 from jvanbruegge/fix-stream

a66aa8aOleg Grenrus8 years ago

doc/tutorial/ApiType.lhs+1−1

compare with master

unifiedsplit

@@ -137,7 +137,7 @@ type StreamGet = Stream 'GET

137type StreamPost = Stream 'POST

138```

139

140−These describe endpoints that return a stream of values rather than just a single value. They not only take a single content type as a parameter, but also a framing strategy -- this specifies how the individual results are delineated from one another in the stream. The two standard strategies given with Servant are `NewlineFraming` and `NetstringFraming`, but others can be written to match other protocols.

140+These describe endpoints that return a stream of values rather than just a single value. They not only take a single content type as a parameter, but also a framing strategy -- this specifies how the individual results are delineated from one another in the stream. The three standard strategies given with Servant are `NewlineFraming`, `NetstringFraming` and `NoFraming`, but others can be written to match other protocols.

141

142

143### `Capture`

servant-client/test/Servant/StreamSpec.hs+3−2

@@ -40,7 +40,8 @@ import Test.QuickCheck

40import Servant.API ((:<|>) ((:<|>)), (:>), JSON,

41 NetstringFraming, NewlineFraming,

42 OctetStream, ResultStream (..),

43− StreamGenerator (..), StreamGet)

43+ StreamGenerator (..), StreamGet,

44+ NoFraming)

44import Servant.Client

45import Servant.Client

45import Servant.ClientSpec (Person (..))

46import Servant.ClientSpec (Person (..))

46import qualified Servant.ClientSpec as CS

47import qualified Servant.ClientSpec as CS

@@ -59,7 +60,7 @@ spec = describe "Servant.Stream" $ do

59type StreamApi f =

60type StreamApi f =

60 "streamGetNewline" :> StreamGet NewlineFraming JSON (f Person)

61 "streamGetNewline" :> StreamGet NewlineFraming JSON (f Person)

61 :<|> "streamGetNetstring" :> StreamGet NetstringFraming JSON (f Person)

62 :<|> "streamGetNetstring" :> StreamGet NetstringFraming JSON (f Person)

62− :<|> "streamALot" :> StreamGet NewlineFraming OctetStream (f BS.ByteString)

63+ :<|> "streamALot" :> StreamGet NoFraming OctetStream (f BS.ByteString)

65capi :: Proxy (StreamApi ResultStream)

66capi :: Proxy (StreamApi ResultStream)

servant-server/src/Servant/Server/Internal.hs+10−10

@@ -284,10 +284,10 @@ instance OVERLAPPING_

284

285instance OVERLAPPABLE_

286 ( MimeRender ctype a, ReflectMethod method,

287− FramingRender framing ctype, ToStreamGenerator f a

287+ FramingRender framing ctype, ToStreamGenerator b a

288− ) => HasServer (Stream method framing ctype (f a)) context where

288+ ) => HasServer (Stream method framing ctype b) context where

289

290− type ServerT (Stream method framing ctype (f a)) m = m (f a)

290+ type ServerT (Stream method framing ctype b) m = m b

291 hoistServerWithContext _ _ nt s = nt s

292

293 route Proxy _ = streamRouter ([],) method (Proxy :: Proxy framing) (Proxy :: Proxy ctype)

@@ -295,23 +295,23 @@ instance OVERLAPPABLE_

295

296instance OVERLAPPING_

297 ( MimeRender ctype a, ReflectMethod method,

298− FramingRender framing ctype, ToStreamGenerator f a,

298+ FramingRender framing ctype, ToStreamGenerator b a,

299− GetHeaders (Headers h (f a))

299+ GetHeaders (Headers h b)

300− ) => HasServer (Stream method framing ctype (Headers h (f a))) context where

300+ ) => HasServer (Stream method framing ctype (Headers h b)) context where

301

302− type ServerT (Stream method framing ctype (Headers h (f a))) m = m (Headers h (f a))

302+ type ServerT (Stream method framing ctype (Headers h b)) m = m (Headers h b)

303 hoistServerWithContext _ _ nt s = nt s

304

305 route Proxy _ = streamRouter (\x -> (getHeaders x, getResponse x)) method (Proxy :: Proxy framing) (Proxy :: Proxy ctype)

306 where method = reflectMethod (Proxy :: Proxy method)

307

308

309−streamRouter :: (MimeRender ctype a, FramingRender framing ctype, ToStreamGenerator f a) =>

309+streamRouter :: (MimeRender ctype a, FramingRender framing ctype, ToStreamGenerator b a) =>

310− (b -> ([(HeaderName, B.ByteString)], f a))

310+ (c -> ([(HeaderName, B.ByteString)], b))

311 -> Method

312 -> Proxy framing

313 -> Proxy ctype

314− -> Delayed env (Handler b)

314+ -> Delayed env (Handler c)

315 -> Router env

316streamRouter splitHeaders method framingproxy ctypeproxy action = leafRouter $ \env request respond ->

317 let accH = fromMaybe ct_wildcard $ lookup hAccept $ requestHeaders request

servant/src/Servant/API.hs+2−2

@@ -117,8 +117,8 @@ import Servant.API.Stream

117 (BoundaryStrategy (..), BuildFromStream (..),

118 ByteStringParser (..), FramingRender (..),

119 FramingUnrender (..), NetstringFraming, NewlineFraming,

120− ResultStream (..), Stream, StreamGenerator (..), StreamGet,

120+ NoFraming, ResultStream (..), Stream, StreamGenerator (..),

121− StreamPost, ToStreamGenerator (..))

121+ StreamGet, StreamPost, ToStreamGenerator (..))

122import Servant.API.Sub

123 ((:>))

124import Servant.API.Vault

servant/src/Servant/API/Stream.hs+17−4

@@ -2,6 +2,7 @@

2{-# LANGUAGE DeriveDataTypeable #-}

3{-# LANGUAGE DeriveGeneric #-}

4{-# LANGUAGE FlexibleInstances #-}

5+{-# LANGUAGE FunctionalDependencies #-}

5{-# LANGUAGE KindSignatures #-}

6{-# LANGUAGE KindSignatures #-}

6{-# LANGUAGE MultiParamTypeClasses #-}

7{-# LANGUAGE MultiParamTypeClasses #-}

7{-# LANGUAGE OverloadedStrings #-}

8{-# LANGUAGE OverloadedStrings #-}

@@ -38,13 +39,13 @@ type StreamGet = Stream 'GET

38type StreamPost = Stream 'POST

39type StreamPost = Stream 'POST

40-- | Stream endpoints may be implemented as producing a @StreamGenerator@ -- a function that itself takes two emit functions -- the first to be used on the first value the stream emits, and the second to be used on all subsequent values (to allow interspersed framing strategies such as comma separation).

41-- | Stream endpoints may be implemented as producing a @StreamGenerator@ -- a function that itself takes two emit functions -- the first to be used on the first value the stream emits, and the second to be used on all subsequent values (to allow interspersed framing strategies such as comma separation).

41−newtype StreamGenerator a = StreamGenerator {getStreamGenerator :: (a -> IO ()) -> (a -> IO ()) -> IO ()}

42+newtype StreamGenerator a = StreamGenerator {getStreamGenerator :: (a -> IO ()) -> (a -> IO ()) -> IO ()}

43-- | ToStreamGenerator is intended to be implemented for types such as Conduit, Pipe, etc. By implementing this class, all such streaming abstractions can be used directly as endpoints.

44-- | ToStreamGenerator is intended to be implemented for types such as Conduit, Pipe, etc. By implementing this class, all such streaming abstractions can be used directly as endpoints.

44−class ToStreamGenerator f a where

45+class ToStreamGenerator a b | a -> b where

45− toStreamGenerator :: f a -> StreamGenerator a

46+ toStreamGenerator :: a -> StreamGenerator b

47−instance ToStreamGenerator StreamGenerator a

48+instance ToStreamGenerator (StreamGenerator a) a

48 where toStreamGenerator x = x

49 where toStreamGenerator x = x

50-- | Clients reading from streaming endpoints can be implemented as producing a @ResultStream@ that captures the setup, takedown, and incremental logic for a read, being an IO continuation that takes a producer of Just either values or errors that terminates with a Nothing.

51-- | Clients reading from streaming endpoints can be implemented as producing a @ResultStream@ that captures the setup, takedown, and incremental logic for a read, being an IO continuation that takes a producer of Just either values or errors that terminates with a Nothing.

@@ -80,6 +81,18 @@ data ByteStringParser a = ByteStringParser {

80class FramingUnrender strategy a where

81class FramingUnrender strategy a where

81 unrenderFrames :: Proxy strategy -> Proxy a -> ByteStringParser (ByteStringParser (Either String ByteString))

82 unrenderFrames :: Proxy strategy -> Proxy a -> ByteStringParser (ByteStringParser (Either String ByteString))

84+-- | A framing strategy that does not do any framing at all, it just passes the input data

85+-- This will be used most of the time with binary data, such as files

86+data NoFraming

87+

88+instance FramingRender NoFraming a where

89+ header _ _ = empty

90+ boundary _ _ = BoundaryStrategyGeneral id

91+ trailer _ _ = empty

92+

93+instance FramingUnrender NoFraming a where

94+ unrenderFrames _ _ = ByteStringParser (Just . (go,)) (go,)

95+ where go = ByteStringParser (Just . (, empty) . Right) ((, empty) . Right)

84-- | A simple framing strategy that has no header or termination, and inserts a newline character between each frame.

97-- | A simple framing strategy that has no header or termination, and inserts a newline character between each frame.

85-- This assumes that it is used with a Content-Type that encodes without newlines (e.g. JSON).

98-- This assumes that it is used with a Content-Type that encodes without newlines (e.g. JSON).