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{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE CPP #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
-- | A full tutorial for this module is available at:
-- <https://github.com/snoyberg/conduit/blob/master/PROCESS.md>.
--
-- Some utilities in this module require the threaded runtime because they use
-- 'System.Process.waitForProcess' internally.
--
-- Note that this is a very thin layer around the @Data.Streaming.Process@ module. In particular, it:
--
-- * Provides orphan instances for conduit
--
-- * Provides some useful helper functions
module Data.Conduit.Process
( -- * Functions
sourceCmdWithConsumer
, sourceProcessWithConsumer
, sourceCmdWithStreams
, sourceProcessWithStreams
, withCheckedProcessCleanup
-- * InputSource types
, FlushInput(..)
, BuilderInput(..)
-- * Reexport
, module Data.Streaming.Process
) where
import Data.Streaming.Process
import Data.Streaming.Process.Internal
import System.Exit (ExitCode (..))
import Control.Monad.IO.Unlift (MonadIO, liftIO, MonadUnliftIO, withRunInIO, withUnliftIO, unliftIO)
import System.IO (hClose, BufferMode (NoBuffering), hSetBuffering)
import Data.Conduit
import Data.Functor (($>))
import Data.Conduit.Binary (sourceHandle, sinkHandle, sinkHandleBuilder, sinkHandleFlush)
import Data.ByteString (ByteString)
import Data.ByteString.Builder (Builder)
import Control.Concurrent.Async (runConcurrently, Concurrently(..))
import Control.Exception (onException, throwIO, finally, bracket, catch)
import System.IO.Error (ioeGetErrorType, isResourceVanishedErrorType)
#if (__GLASGOW_HASKELL__ < 710)
import Control.Applicative ((<$>), (<*>))
#endif
instance (r ~ (), MonadIO m, i ~ ByteString) => InputSource (ConduitM i o m r) where
isStdStream = (\(Just h) -> hSetBuffering h NoBuffering $> sinkHandle h, Just CreatePipe)
instance (r ~ (), r' ~ (), MonadIO m, MonadIO n, i ~ ByteString) => InputSource (ConduitM i o m r, n r') where
isStdStream = (\(Just h) -> hSetBuffering h NoBuffering $> (sinkHandle h, liftIO $ hClose h), Just CreatePipe)
-- | Wrapper for input source which accepts 'Data.ByteString.Builder.Builder's.
-- You can pass 'Data.ByteString.Builder.Extra.flush' to flush the input. Note
-- that the pipe will /not/ automatically close when the processing completes.
--
-- @since 1.3.2
newtype BuilderInput o m r = BuilderInput (ConduitM Builder o m r)
-- | Wrapper for input source which accepts @Flush@es. Note that the pipe
-- will /not/ automatically close then processing completes.
--
-- @since 1.3.2
newtype FlushInput o m r = FlushInput (ConduitM (Flush ByteString) o m r)
instance (MonadIO m, r ~ ()) => InputSource (BuilderInput o m r) where
isStdStream = (\(Just h) -> return $ BuilderInput $ sinkHandleBuilder h, Just CreatePipe)
instance (MonadIO m, MonadIO n, r ~ (), r' ~ ()) => InputSource (BuilderInput o m r, n r') where
isStdStream = (\(Just h) -> return (BuilderInput $ sinkHandleBuilder h, liftIO $ hClose h), Just CreatePipe)
instance (MonadIO m, r ~ ()) => InputSource (FlushInput o m r) where
isStdStream = (\(Just h) -> return $ FlushInput $ sinkHandleFlush h, Just CreatePipe)
instance (MonadIO m, MonadIO n, r ~ (), r' ~ ()) => InputSource (FlushInput o m r, n r') where
isStdStream = (\(Just h) -> return (FlushInput $ sinkHandleFlush h, liftIO $ hClose h), Just CreatePipe)
instance (r ~ (), MonadIO m, o ~ ByteString) => OutputSink (ConduitM i o m r) where
osStdStream = (\(Just h) -> hSetBuffering h NoBuffering $> sourceHandle h, Just CreatePipe)
instance (r ~ (), r' ~ (), MonadIO m, MonadIO n, o ~ ByteString) => OutputSink (ConduitM i o m r, n r') where
osStdStream = (\(Just h) -> hSetBuffering h NoBuffering $> (sourceHandle h, liftIO $ hClose h), Just CreatePipe)
-- | Given a @CreateProcess@, run the process, with its output being used as a
-- @Source@ to feed the provided @Consumer@. Once the process has completed,
-- return a tuple of the @ExitCode@ from the process and the output collected
-- from the @Consumer@.
--
-- Note that, if an exception is raised by the consumer, the process is /not/
-- terminated. This behavior is different from 'sourceProcessWithStreams' due
-- to historical reasons.
--
-- Requires the threaded runtime.
--
-- Since 1.1.2
sourceProcessWithConsumer :: MonadIO m
=> CreateProcess
-> ConduitT ByteString Void m a -- ^ stdout
-> m (ExitCode, a)
sourceProcessWithConsumer cp consumer = do
(ClosedStream, (source, close), ClosedStream, cph) <- streamingProcess cp
res <- runConduit $ source .| consumer
close
ec <- waitForStreamingProcess cph
return (ec, res)
-- | Like @sourceProcessWithConsumer@ but providing the command to be run as
-- a @String@.
--
-- Requires the threaded runtime.
--
-- Since 1.1.2
sourceCmdWithConsumer :: MonadIO m
=> String -- ^command
-> ConduitT ByteString Void m a -- ^stdout
-> m (ExitCode, a)
sourceCmdWithConsumer cmd = sourceProcessWithConsumer (shell cmd)
-- | Given a @CreateProcess@, run the process
-- and feed the provided @Producer@
-- to the stdin @Sink@ of the process.
-- Use the process outputs (stdout, stderr) as @Source@s
-- and feed it to the provided @Consumer@s.
-- Once the process has completed,
-- return a tuple of the @ExitCode@ from the process
-- and the results collected from the @Consumer@s.
--
-- If an exception is raised by any of the streams,
-- the process is terminated.
--
-- IO is required because the streams are run concurrently
-- using the <https://hackage.haskell.org/package/async async> package
--
-- Requires the threaded runtime.
--
-- @since 1.1.12
sourceProcessWithStreams
:: MonadUnliftIO m
=> CreateProcess
-> ConduitT () ByteString m () -- ^stdin
-> ConduitT ByteString Void m a -- ^stdout
-> ConduitT ByteString Void m b -- ^stderr
-> m (ExitCode, a, b)
sourceProcessWithStreams cp producerStdin consumerStdout consumerStderr =
withUnliftIO $ \u -> do
( (sinkStdin, closeStdin)
, (sourceStdout, closeStdout)
, (sourceStderr, closeStderr)
, sph) <- streamingProcess cp
let safeSinkStdin = sinkStdin `catchC` ignoreStdinClosed
safeCloseStdin = closeStdin `catch` ignoreStdinClosed
(_, resStdout, resStderr) <-
runConcurrently (
(,,)
<$> Concurrently ((unliftIO u $ runConduit $ producerStdin .| safeSinkStdin) `finally` safeCloseStdin)
<*> Concurrently (unliftIO u $ runConduit $ sourceStdout .| consumerStdout)
<*> Concurrently (unliftIO u $ runConduit $ sourceStderr .| consumerStderr))
`finally` (closeStdout >> closeStderr)
`onException` terminateStreamingProcess sph
ec <- waitForStreamingProcess sph
return (ec, resStdout, resStderr)
where
ignoreStdinClosed :: forall m. (MonadIO m) => IOError -> m ()
ignoreStdinClosed e =
if isResourceVanishedErrorType (ioeGetErrorType e)
then pure ()
else liftIO (throwIO e)
-- | Like @sourceProcessWithStreams@ but providing the command to be run as
-- a @String@.
--
-- Requires the threaded runtime.
--
-- @since 1.1.12
sourceCmdWithStreams
:: MonadUnliftIO m
=> String -- ^command
-> ConduitT () ByteString m () -- ^stdin
-> ConduitT ByteString Void m a -- ^stdout
-> ConduitT ByteString Void m b -- ^stderr
-> m (ExitCode, a, b)
sourceCmdWithStreams cmd = sourceProcessWithStreams (shell cmd)
-- | Same as 'withCheckedProcess', but kills the child process in the case of
-- an exception being thrown by the provided callback function.
--
-- Requires the threaded runtime.
--
-- @since 1.1.11
withCheckedProcessCleanup
:: ( InputSource stdin
, OutputSink stderr
, OutputSink stdout
, MonadUnliftIO m
)
=> CreateProcess
-> (stdin -> stdout -> stderr -> m b)
-> m b
withCheckedProcessCleanup cp f = withRunInIO $ \run -> bracket
(streamingProcess cp)
(\(_, _, _, sph) -> closeStreamingProcessHandle sph)
$ \(x, y, z, sph) -> do
res <- run (f x y z) `onException` terminateStreamingProcess sph
ec <- waitForStreamingProcess sph
if ec == ExitSuccess
then return res
else throwIO $ ProcessExitedUnsuccessfully cp ec
terminateStreamingProcess :: MonadIO m => StreamingProcessHandle -> m ()
terminateStreamingProcess = liftIO . terminateProcess . streamingProcessHandleRaw
|
