107 lines
3.5 KiB
Haskell
107 lines
3.5 KiB
Haskell
{-# LANGUAGE DataKinds #-}
|
|
{-# LANGUAGE DeriveGeneric #-}
|
|
{-# LANGUAGE TypeOperators #-}
|
|
module Main (main) where
|
|
|
|
import Prelude ()
|
|
import Prelude.Compat
|
|
|
|
import Control.Concurrent
|
|
(threadDelay)
|
|
import Control.Monad.IO.Class
|
|
(MonadIO (..))
|
|
import qualified Data.ByteString as BS
|
|
import Data.Maybe
|
|
(fromMaybe)
|
|
import Network.HTTP.Client
|
|
(defaultManagerSettings, newManager)
|
|
import Network.Wai
|
|
(Application)
|
|
import System.Environment
|
|
(getArgs, lookupEnv)
|
|
import System.IO
|
|
(IOMode (..))
|
|
import Text.Read
|
|
(readMaybe)
|
|
|
|
import qualified Pipes as P
|
|
import Pipes.ByteString as PBS
|
|
import qualified Pipes.Prelude as P
|
|
import Pipes.Safe
|
|
(SafeT)
|
|
import qualified Pipes.Safe.Prelude as P
|
|
import Servant
|
|
import Servant.Client.Streaming
|
|
import Servant.Pipes ()
|
|
|
|
import qualified Network.Wai.Handler.Warp as Warp
|
|
|
|
type FastAPI = "get" :> Capture "num" Int :> StreamGet NewlineFraming JSON (P.Producer Int IO ())
|
|
|
|
-- TODO: Change IO to something with MonadError ServantUnrenderError
|
|
type API = FastAPI
|
|
:<|> "slow" :> Capture "num" Int :> StreamGet NewlineFraming JSON (P.Producer Int IO ())
|
|
-- monad can be SafeT IO too.
|
|
:<|> "readme" :> StreamGet NoFraming OctetStream (P.Producer BS.ByteString (SafeT IO) ())
|
|
-- we can have streaming request body
|
|
:<|> "proxy"
|
|
:> StreamBody NoFraming OctetStream (P.Producer BS.ByteString IO ())
|
|
:> StreamPost NoFraming OctetStream (P.Producer BS.ByteString IO ())
|
|
|
|
api :: Proxy API
|
|
api = Proxy
|
|
|
|
server :: Server API
|
|
server = fast :<|> slow :<|> readme :<|> proxy
|
|
where
|
|
fast n = liftIO $ do
|
|
putStrLn ("/get/" ++ show n)
|
|
return $ fastPipe n
|
|
|
|
slow n = liftIO $ do
|
|
putStrLn ("/slow/" ++ show n)
|
|
return $ slowPipe n
|
|
|
|
readme = liftIO $ do
|
|
putStrLn "/readme"
|
|
return $ P.withFile "README.md" ReadMode $ \h -> PBS.fromHandle h
|
|
|
|
proxy c = liftIO $ do
|
|
putStrLn "/proxy"
|
|
return c
|
|
|
|
-- for some reason unfold leaks?
|
|
fastPipe m
|
|
| m < 0 = return ()
|
|
| otherwise = P.yield m >> fastPipe (m - 1)
|
|
|
|
slowPipe m = fastPipe m P.>-> P.mapM (<$ threadDelay 1000000)
|
|
|
|
app :: Application
|
|
app = serve api server
|
|
|
|
cli :: Client ClientM FastAPI
|
|
cli :<|> _ :<|> _ :<|> _ = client api
|
|
|
|
main :: IO ()
|
|
main = do
|
|
args <- getArgs
|
|
case args of
|
|
("server":_) -> do
|
|
putStrLn "Starting servant-pipes:example at http://localhost:8000"
|
|
port <- fromMaybe 8000 . (>>= readMaybe) <$> lookupEnv "PORT"
|
|
Warp.run port app
|
|
("client":ns:_) -> do
|
|
n <- maybe (fail $ "not a number: " ++ ns) pure $ readMaybe ns
|
|
mgr <- newManager defaultManagerSettings
|
|
burl <- parseBaseUrl "http://localhost:8000/"
|
|
withClientM (cli n) (mkClientEnv mgr burl) $ \me -> case me of
|
|
Left err -> print err
|
|
Right p -> do
|
|
x <- P.fold (\c _ -> c + 1) (0 :: Int) id p
|
|
print x
|
|
_ -> do
|
|
putStrLn "Try:"
|
|
putStrLn "cabal new-run servant-pipes:example server"
|
|
putStrLn "cabal new-run servant-pipes:example client 10"
|
|
putStrLn "time curl -H 'Accept: application/json' localhost:8000/slow/5"
|