ghcup-hs/lib/GHCup/Utils/File.hs
Julian Ospald 78ae77780b
Fix bug in logging thread
It would die on newlines due to empty String blindness.
Also make sure takeMVar does not block.
2020-07-21 22:43:09 +02:00

418 lines
14 KiB
Haskell

{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE TemplateHaskell #-}
module GHCup.Utils.File where
import GHCup.Utils.Dirs
import GHCup.Utils.Prelude
import GHCup.Types
import Control.Concurrent
import Control.Concurrent.Async
import Control.Exception ( evaluate )
import Control.Exception.Safe
import Control.Monad
import Control.Monad.Reader
import Control.Monad.Trans.State.Strict
import Data.ByteString ( ByteString )
import Data.Foldable
import Data.Functor
import Data.IORef
import Data.Maybe
import Data.Sequence ( Seq, (|>) )
import Data.Text ( Text )
import Data.Void
import Data.Word8
import GHC.IO.Exception
import HPath
import HPath.IO hiding ( hideError )
import Optics hiding ((<|), (|>))
import System.Console.Pretty
import System.Console.Regions
import System.IO.Error
import System.Posix.Directory.ByteString
import System.Posix.FD as FD
import System.Posix.FilePath hiding ( (</>) )
import System.Posix.Foreign ( oExcl )
import "unix" System.Posix.IO.ByteString
hiding ( openFd )
import System.Posix.Process ( ProcessStatus(..) )
import System.Posix.Types
import Text.Regex.Posix
import qualified Control.Exception as EX
import qualified Data.Sequence as Sq
import qualified Data.Text as T
import qualified Data.Text.Encoding as E
import qualified System.Posix.Process.ByteString
as SPPB
import Streamly.External.Posix.DirStream
import qualified Streamly.Prelude as S
import qualified Text.Megaparsec as MP
import qualified Data.ByteString as BS
import qualified "unix-bytestring" System.Posix.IO.ByteString
as SPIB
data ProcessError = NonZeroExit Int ByteString [ByteString]
| PTerminated ByteString [ByteString]
| PStopped ByteString [ByteString]
| NoSuchPid ByteString [ByteString]
deriving Show
data CapturedProcess = CapturedProcess
{ _exitCode :: ExitCode
, _stdOut :: ByteString
, _stdErr :: ByteString
}
deriving (Eq, Show)
makeLenses ''CapturedProcess
-- | Find the given executable by searching all *absolute* PATH components.
-- Relative paths in PATH are ignored.
--
-- This shouldn't throw IO exceptions, unless getting the environment variable
-- PATH does.
findExecutable :: Path Rel -> IO (Maybe (Path Abs))
findExecutable ex = do
sPaths <- fmap catMaybes . (fmap . fmap) parseAbs $ getSearchPath
-- We don't want exceptions to mess up our result. If we can't
-- figure out if a file exists, then treat it as a negative result.
asum $ fmap (handleIO (\_ -> pure Nothing)) $ fmap
-- asum for short-circuiting behavior
(\s' -> (isExecutable (s' </> ex) >>= guard) $> (Just (s' </> ex)))
sPaths
-- | Execute the given command and collect the stdout, stderr and the exit code.
-- The command is run in a subprocess.
executeOut :: Path b -- ^ command as filename, e.g. 'ls'
-> [ByteString] -- ^ arguments to the command
-> Maybe (Path Abs) -- ^ chdir to this path
-> IO CapturedProcess
executeOut path args chdir = captureOutStreams $ do
maybe (pure ()) (changeWorkingDirectory . toFilePath) chdir
SPPB.executeFile (toFilePath path) True args Nothing
execLogged :: (MonadReader Settings m, MonadIO m, MonadThrow m)
=> ByteString -- ^ thing to execute
-> Bool -- ^ whether to search PATH for the thing
-> [ByteString] -- ^ args for the thing
-> Path Rel -- ^ log filename
-> Maybe (Path Abs) -- ^ optionally chdir into this
-> Maybe [(ByteString, ByteString)] -- ^ optional environment
-> m (Either ProcessError ())
execLogged exe spath args lfile chdir env = do
Settings {..} <- ask
ldir <- liftIO ghcupLogsDir
logfile <- (ldir </>) <$> parseRel (toFilePath lfile <> ".log")
liftIO $ bracket (createFile (toFilePath logfile) newFilePerms)
closeFd
(action verbose)
where
action verbose fd = do
actionWithPipes $ \(stdoutRead, stdoutWrite) -> do
-- start the thread that logs to stdout
pState <- newEmptyMVar
done <- newEmptyMVar
void
$ forkIO
$ EX.handle (\(_ :: IOException) -> pure ())
$ flip EX.finally (putMVar done ())
$ (if verbose
then tee fd stdoutRead
else printToRegion fd stdoutRead 6 pState
)
-- fork the subprocess
pid <- SPPB.forkProcess $ do
void $ dupTo stdoutWrite stdOutput
void $ dupTo stdoutWrite stdError
closeFd stdoutRead
closeFd stdoutWrite
-- execute the action
maybe (pure ()) (changeWorkingDirectory . toFilePath) chdir
void $ SPPB.executeFile exe spath args env
closeFd stdoutWrite
-- wait for the subprocess to finish
e <- toProcessError exe args <$!> SPPB.getProcessStatus True True pid
putMVar pState (either (const False) (const True) e)
void $ race (takeMVar done) (threadDelay (1000000 * 3))
closeFd stdoutRead
pure e
tee :: Fd -> Fd -> IO ()
tee fileFd fdIn = readTilEOF lineAction fdIn
where
lineAction :: ByteString -> IO ()
lineAction bs' = do
void $ SPIB.fdWrite fileFd (bs' <> "\n")
void $ SPIB.fdWrite stdOutput (bs' <> "\n")
-- Reads fdIn and logs the output in a continous scrolling area
-- of 'size' terminal lines. Also writes to a log file.
printToRegion :: Fd -> Fd -> Int -> MVar Bool -> IO ()
printToRegion fileFd fdIn size pState = do
void $ displayConsoleRegions $ do
rs <-
liftIO
. fmap Sq.fromList
. sequence
. replicate size
. openConsoleRegion
$ Linear
flip runStateT mempty
$ handle
(\(ex :: SomeException) -> do
ps <- liftIO $ takeMVar pState
when (ps == True) (forM_ rs (liftIO . closeConsoleRegion))
throw ex
)
$ readTilEOF (lineAction rs) fdIn
where
-- action to perform line by line
-- TODO: do this with vty for efficiency
lineAction :: (MonadMask m, MonadIO m)
=> Seq ConsoleRegion
-> ByteString
-> StateT (Seq ByteString) m ()
lineAction rs = \bs' -> do
void $ liftIO $ SPIB.fdWrite fileFd (bs' <> "\n")
modify (swapRegs bs')
regs <- get
liftIO $ forM_ (Sq.zip regs rs) $ \(bs, r) -> setConsoleRegion r $ do
w <- consoleWidth
return
. T.pack
. color Blue
. T.unpack
. decUTF8Safe
. trim w
. (\b -> "[ " <> toFilePath lfile <> " ] " <> b)
$ bs
swapRegs :: a -> Seq a -> Seq a
swapRegs bs = \regs -> if
| Sq.length regs < size -> regs |> bs
| otherwise -> Sq.drop 1 regs |> bs
-- trim output line to terminal width
trim :: Int -> ByteString -> ByteString
trim w = \bs -> if
| BS.length bs > w && w > 5 -> BS.take (w - 4) bs <> "..."
| otherwise -> bs
-- Consecutively read from Fd in 512 chunks until we hit
-- newline or EOF.
readLine :: MonadIO m
=> Fd -- ^ input file descriptor
-> ByteString -- ^ rest buffer (read across newline)
-> m (ByteString, ByteString, Bool) -- ^ (full line, rest, eof)
readLine fd = \inBs -> go inBs
where
go inBs = do
-- if buffer is not empty, process it first
mbs <- if BS.length inBs == 0
-- otherwise attempt read
then liftIO
$ handleIO (\e -> if isEOFError e then pure Nothing else ioError e)
$ fmap Just
$ SPIB.fdRead fd 512
else pure $ Just inBs
case mbs of
Nothing -> pure ("", "", True)
Just bs -> do
-- split on newline
let (line, rest) = BS.span (/= _lf) bs
if
| BS.length rest /= 0 -> pure (line, BS.tail rest, False)
-- if rest is empty, then there was no newline, process further
| otherwise -> (\(l, r, b) -> (line <> l, r, b)) <$!> go mempty
readTilEOF :: MonadIO m => (ByteString -> m a) -> Fd -> m ()
readTilEOF ~action' fd' = go mempty
where
go bs' = do
(bs, rest, eof) <- readLine fd' bs'
if eof
then liftIO $ ioError (mkIOError eofErrorType "" Nothing Nothing)
else (void $ action' bs) >> go rest
-- | Capture the stdout and stderr of the given action, which
-- is run in a subprocess. Stdin is closed. You might want to
-- 'race' this to make sure it terminates.
captureOutStreams :: IO a
-- ^ the action to execute in a subprocess
-> IO CapturedProcess
captureOutStreams action = do
actionWithPipes $ \(parentStdoutRead, childStdoutWrite) ->
actionWithPipes $ \(parentStderrRead, childStderrWrite) -> do
pid <- SPPB.forkProcess $ do
-- dup stdout
void $ dupTo childStdoutWrite stdOutput
closeFd childStdoutWrite
closeFd parentStdoutRead
-- dup stderr
void $ dupTo childStderrWrite stdError
closeFd childStderrWrite
closeFd parentStderrRead
-- execute the action
a <- action
void $ evaluate a
-- close everything we don't need
closeFd childStdoutWrite
closeFd childStderrWrite
-- start thread that writes the output
refOut <- newIORef BS.empty
refErr <- newIORef BS.empty
done <- newEmptyMVar
_ <-
forkIO
$ EX.handle (\(_ :: IOException) -> pure ())
$ flip EX.finally (putMVar done ())
$ writeStds parentStdoutRead parentStderrRead refOut refErr
status <- SPPB.getProcessStatus True True pid
void $ race (takeMVar done) (threadDelay (1000000 * 3))
case status of
-- readFd will take care of closing the fd
Just (SPPB.Exited es) -> do
stdout' <- readIORef refOut
stderr' <- readIORef refErr
pure $ CapturedProcess { _exitCode = es
, _stdOut = stdout'
, _stdErr = stderr'
}
_ -> throwIO $ userError $ ("No such PID " ++ show pid)
where
writeStds pout perr rout rerr = do
doneOut <- newEmptyMVar
void
$ forkIO
$ hideError eofErrorType
$ flip EX.finally (putMVar doneOut ())
$ readTilEOF (\x -> modifyIORef' rout (<> x)) pout
doneErr <- newEmptyMVar
void
$ forkIO
$ hideError eofErrorType
$ flip EX.finally (putMVar doneErr ())
$ readTilEOF (\x -> modifyIORef' rerr (<> x)) perr
takeMVar doneOut
takeMVar doneErr
readTilEOF ~action' fd' = do
bs <- SPIB.fdRead fd' 512
void $ action' bs
readTilEOF action' fd'
actionWithPipes :: ((Fd, Fd) -> IO b) -> IO b
actionWithPipes a =
createPipe >>= \(p1, p2) -> (flip finally) (cleanup [p1, p2]) $ a (p1, p2)
cleanup :: [Fd] -> IO ()
cleanup fds = for_ fds $ \fd -> handleIO (\_ -> pure ()) $ closeFd fd
-- | Create a new regular file in write-only mode. The file must not exist.
createRegularFileFd :: FileMode -> Path b -> IO Fd
createRegularFileFd fm dest =
FD.openFd (toFilePath dest) WriteOnly [oExcl] (Just fm)
-- | Thin wrapper around `executeFile`.
exec :: ByteString -- ^ thing to execute
-> Bool -- ^ whether to search PATH for the thing
-> [ByteString] -- ^ args for the thing
-> Maybe (Path Abs) -- ^ optionally chdir into this
-> Maybe [(ByteString, ByteString)] -- ^ optional environment
-> IO (Either ProcessError ())
exec exe spath args chdir env = do
pid <- SPPB.forkProcess $ do
maybe (pure ()) (changeWorkingDirectory . toFilePath) chdir
SPPB.executeFile exe spath args env
fmap (toProcessError exe args) $ SPPB.getProcessStatus True True pid
toProcessError :: ByteString
-> [ByteString]
-> Maybe ProcessStatus
-> Either ProcessError ()
toProcessError exe args mps = case mps of
Just (SPPB.Exited (ExitFailure i)) -> Left $ NonZeroExit i exe args
Just (SPPB.Exited ExitSuccess ) -> Right ()
Just (Terminated _ _ ) -> Left $ PTerminated exe args
Just (Stopped _ ) -> Left $ PStopped exe args
Nothing -> Left $ NoSuchPid exe args
-- | Search for a file in the search paths.
--
-- Catches `PermissionDenied` and `NoSuchThing` and returns `Nothing`.
searchPath :: [Path Abs] -> Path Rel -> IO (Maybe (Path Abs))
searchPath paths needle = go paths
where
go [] = pure Nothing
go (x : xs) =
hideErrorDefM [InappropriateType, PermissionDenied, NoSuchThing] (go xs)
$ do
dirStream <- openDirStream (toFilePath x)
S.findM (\(_, p) -> isMatch x p) (dirContentsStream dirStream)
>>= \case
Just _ -> pure $ Just (x </> needle)
Nothing -> go xs
isMatch basedir p = do
if p == toFilePath needle
then isExecutable (basedir </> needle)
else pure False
findFiles :: Path Abs -> Regex -> IO [Path Rel]
findFiles path regex = do
dirStream <- openDirStream (toFilePath path)
f <-
(fmap . fmap) snd
. S.toList
. S.filter (\(_, p) -> match regex p)
$ dirContentsStream dirStream
pure $ join $ fmap parseRel f
findFiles' :: Path Abs -> MP.Parsec Void Text () -> IO [Path Rel]
findFiles' path parser = do
dirStream <- openDirStream (toFilePath path)
f <-
(fmap . fmap) snd
. S.toList
. S.filter (\(_, p) -> case E.decodeUtf8' p of
Left _ -> False
Right p' -> isJust $ MP.parseMaybe parser p')
$ dirContentsStream dirStream
pure $ join $ fmap parseRel f