ghcup-hs/lib/GHCup/Utils/File/Posix.hs

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{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE FlexibleContexts #-}
{-|
Module : GHCup.Utils.File.Posix
Description : File and unix APIs
Copyright : (c) Julian Ospald, 2020
License : LGPL-3.0
Maintainer : hasufell@hasufell.de
Stability : experimental
Portability : POSIX
This module handles file and executable handling.
Some of these functions use sophisticated logging.
-}
module GHCup.Utils.File.Posix where
import GHCup.Utils.File.Common
import GHCup.Utils.Prelude
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import GHCup.Utils.Logger
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import GHCup.Types
import GHCup.Types.Optics
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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.IORef
import Data.Sequence ( Seq, (|>) )
import Data.List
import Data.Word8
import GHC.IO.Exception
import System.Console.Terminal.Common
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import System.IO.Error
import System.FilePath
import System.Directory
import System.Posix.Directory
import System.Posix.Files
import System.Posix.IO
import System.Posix.Process ( ProcessStatus(..) )
import System.Posix.Types
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 as SPP
import qualified System.Console.Terminal.Posix as TP
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import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy as BL
import qualified "unix-bytestring" System.Posix.IO.ByteString
as SPIB
-- | Execute the given command and collect the stdout, stderr and the exit code.
-- The command is run in a subprocess.
executeOut :: MonadIO m
=> FilePath -- ^ command as filename, e.g. 'ls'
-> [String] -- ^ arguments to the command
-> Maybe FilePath -- ^ chdir to this path
-> m CapturedProcess
executeOut path args chdir = liftIO $ captureOutStreams $ do
maybe (pure ()) changeWorkingDirectory chdir
SPP.executeFile path True args Nothing
execLogged :: ( MonadReader env m
, HasSettings env
, HasDirs env
, MonadIO m
, MonadThrow m)
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=> FilePath -- ^ thing to execute
-> [String] -- ^ args for the thing
-> Maybe FilePath -- ^ optionally chdir into this
-> FilePath -- ^ log filename (opened in append mode)
-> Maybe [(String, String)] -- ^ optional environment
-> m (Either ProcessError ())
execLogged exe args chdir lfile env = do
Settings {..} <- getSettings
Dirs {..} <- getDirs
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let logfile = logsDir </> lfile <> ".log"
liftIO $ bracket (openFd logfile WriteOnly (Just newFilePerms) defaultFileFlags{ append = True })
closeFd
(action verbose noColor)
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where
action verbose no_color fd = do
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actionWithPipes $ \(stdoutRead, stdoutWrite) -> do
-- start the thread that logs to stdout
pState <- newEmptyMVar
done <- newEmptyMVar
void
$ forkIO
$ EX.handle (\(_ :: IOException) -> pure ())
$ EX.finally
(if verbose
then tee fd stdoutRead
else printToRegion fd stdoutRead 6 pState no_color
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)
(putMVar done ())
-- fork the subprocess
pid <- SPP.forkProcess $ do
void $ dupTo stdoutWrite stdOutput
void $ dupTo stdoutWrite stdError
closeFd stdoutRead
closeFd stdoutWrite
-- execute the action
maybe (pure ()) changeWorkingDirectory chdir
void $ SPP.executeFile exe (not ("./" `isPrefixOf` exe)) args env
closeFd stdoutWrite
-- wait for the subprocess to finish
e <- toProcessError exe args <$!> SPP.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 ()
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tee fileFd = readTilEOF lineAction
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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 -> Bool -> IO ()
printToRegion fileFd fdIn size pState no_color = do
-- init region
forM_ [1..size] $ \_ -> BS.putStr "\n"
void $ flip runStateT mempty
$ do
handle
(\(ex :: SomeException) -> do
ps <- liftIO $ takeMVar pState
when ps (liftIO $ BS.putStr (pos1 <> moveLineUp size <> clearScreen))
throw ex
) $ readTilEOF lineAction fdIn
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where
clearScreen :: ByteString
clearScreen = "\x1b[0J"
clearLine :: ByteString
clearLine = "\x1b[2K"
moveLineUp :: Int -> ByteString
moveLineUp n = "\x1b[" <> E.encodeUtf8 (T.pack (show n)) <> "A"
moveLineDown :: Int -> ByteString
moveLineDown n = "\x1b[" <> E.encodeUtf8 (T.pack (show n)) <> "B"
pos1 :: ByteString
pos1 = "\r"
overwriteNthLine :: Int -> ByteString -> ByteString
overwriteNthLine n str = pos1 <> moveLineUp n <> clearLine <> str <> moveLineDown n <> pos1
blue :: ByteString -> ByteString
blue bs
| no_color = bs
| otherwise = "\x1b[0;34m" <> bs <> "\x1b[0m"
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-- action to perform line by line
lineAction :: (MonadMask m, MonadIO m)
=> ByteString
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-> StateT (Seq ByteString) m ()
lineAction = \bs' -> do
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void $ liftIO $ SPIB.fdWrite fileFd (bs' <> "\n")
modify (swapRegs bs')
liftIO TP.size >>= \case
Nothing -> pure ()
Just (Window _ w) -> do
regs <- get
liftIO $ forM_ (Sq.zip regs (Sq.fromList [0..(Sq.length regs - 1)])) $ \(bs, i) -> do
BS.putStr
. overwriteNthLine (size - i)
. trim w
. blue
. (\b -> "[ " <> E.encodeUtf8 (T.pack lfile) <> " ] " <> b)
$ bs
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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 = go
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 <- SPP.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 BL.empty
refErr <- newIORef BL.empty
done <- newEmptyMVar
_ <-
forkIO
$ EX.handle (\(_ :: IOException) -> pure ())
$ flip EX.finally (putMVar done ())
$ writeStds parentStdoutRead parentStderrRead refOut refErr
status <- SPP.getProcessStatus True True pid
void $ race (takeMVar done) (threadDelay (1000000 * 3))
case status of
-- readFd will take care of closing the fd
Just (SPP.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 :: Fd -> Fd -> IORef BL.ByteString -> IORef BL.ByteString -> IO ()
writeStds pout perr rout rerr = do
doneOut <- newEmptyMVar
void
$ forkIO
$ hideError eofErrorType
$ flip EX.finally (putMVar doneOut ())
$ readTilEOF (\x -> modifyIORef' rout (<> BL.fromStrict x)) pout
doneErr <- newEmptyMVar
void
$ forkIO
$ hideError eofErrorType
$ flip EX.finally (putMVar doneErr ())
$ readTilEOF (\x -> modifyIORef' rerr (<> BL.fromStrict 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 -> FilePath -> IO Fd
createRegularFileFd fm dest =
openFd dest WriteOnly (Just fm) defaultFileFlags{ exclusive = True }
-- | Thin wrapper around `executeFile`.
exec :: MonadIO m
=> String -- ^ thing to execute
-> [String] -- ^ args for the thing
-> Maybe FilePath -- ^ optionally chdir into this
-> Maybe [(String, String)] -- ^ optional environment
-> m (Either ProcessError ())
exec exe args chdir env = liftIO $ do
pid <- SPP.forkProcess $ do
maybe (pure ()) changeWorkingDirectory chdir
SPP.executeFile exe (not ("./" `isPrefixOf` exe)) args env
fmap (toProcessError exe args) $ SPP.getProcessStatus True True pid
toProcessError :: FilePath
-> [String]
-> Maybe ProcessStatus
-> Either ProcessError ()
toProcessError exe args mps = case mps of
Just (SPP.Exited (ExitFailure xi)) -> Left $ NonZeroExit xi exe args
Just (SPP.Exited ExitSuccess ) -> Right ()
Just (Terminated _ _ ) -> Left $ PTerminated exe args
Just (Stopped _ ) -> Left $ PStopped exe args
Nothing -> Left $ NoSuchPid exe args
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chmod_755 :: (MonadReader env m, HasLog env, MonadIO m) => FilePath -> m ()
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chmod_755 fp = do
let exe_mode =
nullFileMode
`unionFileModes` ownerExecuteMode
`unionFileModes` ownerReadMode
`unionFileModes` ownerWriteMode
`unionFileModes` groupExecuteMode
`unionFileModes` groupReadMode
`unionFileModes` otherExecuteMode
`unionFileModes` otherReadMode
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logDebug ("chmod 755 " <> T.pack fp)
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liftIO $ setFileMode fp exe_mode
-- |Default permissions for a new file.
newFilePerms :: FileMode
newFilePerms =
ownerWriteMode
`unionFileModes` ownerReadMode
`unionFileModes` groupWriteMode
`unionFileModes` groupReadMode
`unionFileModes` otherWriteMode
`unionFileModes` otherReadMode
-- | Checks whether the binary is a broken link.
isBrokenSymlink :: FilePath -> IO Bool
isBrokenSymlink fp = do
try (pathIsSymbolicLink fp) >>= \case
Right True -> do
let symDir = takeDirectory fp
tfp <- getSymbolicLinkTarget fp
not <$> doesPathExist
-- this drops 'symDir' if 'tfp' is absolute
(symDir </> tfp)
Right b -> pure b
Left e | isDoesNotExistError e -> pure False
| otherwise -> throwIO e