104 lines
3.3 KiB
Haskell
104 lines
3.3 KiB
Haskell
{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE DeriveGeneric #-}
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{-# LANGUAGE TypeOperators #-}
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module Main (main) where
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import Prelude ()
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import Prelude.Compat
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import Control.Concurrent
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(threadDelay)
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import Control.Monad.IO.Class
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(MonadIO (..))
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import Control.Monad.Trans.Resource
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(ResourceT)
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import qualified Data.ByteString as BS
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import Data.Maybe
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(fromMaybe)
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import Network.HTTP.Client
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(defaultManagerSettings, newManager)
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import Network.Wai
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(Application)
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import System.Environment
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(getArgs, lookupEnv)
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import Text.Read
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(readMaybe)
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import Data.Conduit
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import qualified Data.Conduit.Combinators as C
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import Servant
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import Servant.Client
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import Servant.Conduit ()
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import qualified Network.Wai.Handler.Warp as Warp
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type FastAPI = "get" :> Capture "num" Int :> StreamGet NewlineFraming JSON (ConduitT () Int IO ())
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type API = FastAPI
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:<|> "slow" :> Capture "num" Int :> StreamGet NewlineFraming JSON (ConduitT () Int IO ())
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-- monad can be ResourceT IO too.
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:<|> "readme" :> StreamGet NoFraming OctetStream (ConduitT () BS.ByteString (ResourceT IO) ())
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-- we can have streaming request body
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:<|> "proxy"
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:> StreamBody NoFraming OctetStream (ConduitT () BS.ByteString IO ())
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:> StreamPost NoFraming OctetStream (ConduitT () BS.ByteString IO ())
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api :: Proxy API
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api = Proxy
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server :: Server API
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server = fast :<|> slow :<|> readme :<|> proxy
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where
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fast n = liftIO $ do
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putStrLn $ "/get/" ++ show n
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return $ fastConduit n
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slow n = liftIO $ do
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putStrLn $ "/slow/" ++ show n
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return $ slowConduit n
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readme = liftIO $ do
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putStrLn "/proxy"
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return (C.sourceFile "README.md")
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proxy c = liftIO $ do
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putStrLn "/proxy"
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return c
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-- for some reason unfold leaks?
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fastConduit = C.unfold mk where
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mk m
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| m < 0 = Nothing
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| otherwise = Just (m, pred m)
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slowConduit m = fastConduit m .| C.mapM (<$ threadDelay 1000000)
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app :: Application
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app = serve api server
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cli :: Client ClientM FastAPI
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cli :<|> _ :<|> _ :<|> _ = client api
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main :: IO ()
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main = do
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args <- getArgs
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case args of
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("server":_) -> do
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putStrLn "Starting servant-conduit:example at http://localhost:8000"
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port <- fromMaybe 8000 . (>>= readMaybe) <$> lookupEnv "PORT"
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Warp.run port app
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("client":ns:_) -> do
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n <- maybe (fail $ "not a number: " ++ ns) pure $ readMaybe ns
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mgr <- newManager defaultManagerSettings
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burl <- parseBaseUrl "http://localhost:8000/"
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withClientM (cli n) (mkClientEnv mgr burl) $ \me -> case me of
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Left err -> print err
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Right c -> do
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x <- connect c $ C.foldl (\p _ -> p + 1) (0 :: Int)
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print x
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_ -> do
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putStrLn "Try:"
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putStrLn "cabal new-run servant-conduit:example server"
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putStrLn "cabal new-run servant-conduit:example client 10"
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putStrLn "time curl -H 'Accept: application/json' localhost:8000/slow/5"
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