a66aa8a · servant · git.iko.soy

git.iko.soy/servant

Merge pull request #959 from jvanbruegge/fix-stream

Change definition of StreamGenerator

commita66aa8a98177eae5ceb0f3990d250ed0fb62aea4 authorOleg Grenrus <oleg.grenrus@iki.fi> dateMon 28 May 2018, 09:26 (8 years ago) parent64cb1f3 a0b6d7a

5 files changed+33−19

compare with master

unifiedsplit

doc/tutorial/ApiType.lhs+1−1 servant-client/test/Servant/StreamSpec.hs+3−2 servant-server/src/Servant/Server/Internal.hs+10−10 servant/src/Servant/API.hs+2−2 servant/src/Servant/API/Stream.hs+17−4

doc/tutorial/ApiType.lhs+1−1

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

137137type StreamPost = Stream 'POST

138138```

139139

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.

141141

142142

143143### `Capture`

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

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

4040import Servant.API ((:<|>) ((:<|>)), (:>), JSON,

4141 NetstringFraming, NewlineFraming,

4242 OctetStream, ResultStream (..),

43− StreamGenerator (..), StreamGet)

43+ StreamGenerator (..), StreamGet,

44+ NoFraming)

4445import Servant.Client

4546import Servant.ClientSpec (Person (..))

4647import qualified Servant.ClientSpec as CS

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

5960type StreamApi f =

6061 "streamGetNewline" :> StreamGet NewlineFraming JSON (f Person)

6162 :<|> "streamGetNetstring" :> StreamGet NetstringFraming JSON (f Person)

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

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

6364

6465

6566capi :: Proxy (StreamApi ResultStream)

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

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

284284

285285instance OVERLAPPABLE_

286286 ( MimeRender ctype a, ReflectMethod method,

287− FramingRender framing ctype, ToStreamGenerator f a

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

287+ FramingRender framing ctype, ToStreamGenerator b a

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

289289

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

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

291291 hoistServerWithContext _ _ nt s = nt s

292292

293293 route Proxy _ = streamRouter ([],) method (Proxy :: Proxy framing) (Proxy :: Proxy ctype)

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

295295

296296instance OVERLAPPING_

297297 ( MimeRender ctype a, ReflectMethod method,

298− FramingRender framing ctype, ToStreamGenerator f a,

299− GetHeaders (Headers h (f a))

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

298+ FramingRender framing ctype, ToStreamGenerator b a,

299+ GetHeaders (Headers h b)

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

301301

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)

303303 hoistServerWithContext _ _ nt s = nt s

304304

305305 route Proxy _ = streamRouter (\x -> (getHeaders x, getResponse x)) method (Proxy :: Proxy framing) (Proxy :: Proxy ctype)

306306 where method = reflectMethod (Proxy :: Proxy method)

307307

308308

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

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

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

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

311311 -> Method

312312 -> Proxy framing

313313 -> Proxy ctype

314− -> Delayed env (Handler b)

314+ -> Delayed env (Handler c)

315315 -> Router env

316316streamRouter splitHeaders method framingproxy ctypeproxy action = leafRouter $ \env request respond ->

317317 let accH = fromMaybe ct_wildcard $ lookup hAccept $ requestHeaders request

servant/src/Servant/API.hs+2−2

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

117117 (BoundaryStrategy (..), BuildFromStream (..),

118118 ByteStringParser (..), FramingRender (..),

119119 FramingUnrender (..), NetstringFraming, NewlineFraming,

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

121− StreamPost, ToStreamGenerator (..))

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

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

122122import Servant.API.Sub

123123 ((:>))

124124import Servant.API.Vault

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

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

22{-# LANGUAGE DeriveDataTypeable #-}

33{-# LANGUAGE DeriveGeneric #-}

44{-# LANGUAGE FlexibleInstances #-}

5+{-# LANGUAGE FunctionalDependencies #-}

56{-# LANGUAGE KindSignatures #-}

67{-# LANGUAGE MultiParamTypeClasses #-}

78{-# LANGUAGE OverloadedStrings #-}

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

3839type StreamPost = Stream 'POST

3940

4041-- | 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 ()}

4243

4344-- | 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− toStreamGenerator :: f a -> StreamGenerator a

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

46+ toStreamGenerator :: a -> StreamGenerator b

4647

47−instance ToStreamGenerator StreamGenerator a

48+instance ToStreamGenerator (StreamGenerator a) a

4849 where toStreamGenerator x = x

4950

5051-- | 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 {

8081class FramingUnrender strategy a where

8182 unrenderFrames :: Proxy strategy -> Proxy a -> ByteStringParser (ByteStringParser (Either String ByteString))

8283

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)

8396

8497-- | A simple framing strategy that has no header or termination, and inserts a newline character between each frame.

8598-- This assumes that it is used with a Content-Type that encodes without newlines (e.g. JSON).