ghcup-hs/lib/GHCup/Utils/File/Posix.hs
Julian Ospald 48aee1e76c
[WIP] Prototype of recording installed files
This also installs makefile based build system via DESTDIR
into a temporary directory and then merges it into the filesystem.
2022-05-13 00:46:47 +02:00

566 lines
19 KiB
Haskell

{-# 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
import GHCup.Utils.Logger
import GHCup.Types
import GHCup.Types.Optics
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 Foreign.C.String
import Foreign.C.Types
import GHC.IO.Exception
import System.IO ( stderr, hClose, hSetBinaryMode )
import System.IO.Error
import System.FilePath
import System.Directory hiding ( copyFile )
import System.Posix.Directory
import System.Posix.Error ( throwErrnoPathIfMinus1Retry )
import System.Posix.Internals ( withFilePath )
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.Files as PF
import qualified System.Posix.Process as SPP
import qualified System.Posix.IO as SPI
import qualified System.Console.Terminal.Size as TP
import qualified System.Posix as Posix
import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy as BL
import qualified "unix-bytestring" System.Posix.IO.ByteString
as SPIB
import qualified Streamly.FileSystem.Handle as FH
import qualified Streamly.Internal.FileSystem.Handle
as IFH
import qualified Streamly.Prelude as S
import qualified GHCup.Utils.File.Posix.Foreign as FD
-- | 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
, HasLog env
, HasDirs env
, MonadIO m
, MonadThrow m)
=> 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
logDebug $ T.pack $ "Running " <> exe <> " with arguments " <> show args
let logfile = logsDir </> lfile <> ".log"
liftIO $ bracket (openFd logfile WriteOnly (Just newFilePerms) defaultFileFlags{ append = True })
closeFd
(action verbose noColor)
where
action verbose no_color fd = do
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
)
(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 ()
tee fileFd = readTilEOF lineAction
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.hPut stderr "\n"
void $ flip runStateT mempty
$ do
handle
(\(ex :: SomeException) -> do
ps <- liftIO $ takeMVar pState
when ps (liftIO $ BS.hPut stderr (pos1 <> moveLineUp size <> clearScreen))
throw ex
) $ readTilEOF lineAction fdIn
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"
-- action to perform line by line
lineAction :: (MonadMask m, MonadIO m)
=> ByteString
-> StateT (Seq ByteString) m ()
lineAction = \bs' -> do
void $ liftIO $ SPIB.fdWrite fileFd (bs' <> "\n")
modify (swapRegs bs')
liftIO TP.size >>= \case
Nothing -> pure ()
Just (TP.Window _ w) -> do
regs <- get
liftIO $ forM_ (Sq.zip regs (Sq.fromList [0..(Sq.length regs - 1)])) $ \(bs, i) -> do
BS.hPut stderr
. overwriteNthLine (size - i)
. trim w
. blue
. (\b -> "[ " <> E.encodeUtf8 (T.pack 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 = 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
chmod_755 :: (MonadReader env m, HasLog env, MonadIO m) => FilePath -> m ()
chmod_755 fp = do
let exe_mode =
nullFileMode
`unionFileModes` ownerExecuteMode
`unionFileModes` ownerReadMode
`unionFileModes` ownerWriteMode
`unionFileModes` groupExecuteMode
`unionFileModes` groupReadMode
`unionFileModes` otherExecuteMode
`unionFileModes` otherReadMode
logDebug ("chmod 755 " <> T.pack fp)
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
copyFile :: FilePath -- ^ source file
-> FilePath -- ^ destination file
-> Bool -- ^ fail if file exists
-> IO ()
copyFile from to fail' = do
bracket
(do
fd <- openFd' from SPI.ReadOnly [FD.oNofollow] Nothing
handle' <- SPI.fdToHandle fd
pure (fd, handle')
)
(\(_, handle') -> hClose handle')
$ \(fromFd, fH) -> do
sourceFileMode <- fileMode
<$> getFdStatus fromFd
let dflags =
[ FD.oNofollow
, case fail' of
True -> FD.oExcl
False -> FD.oTrunc
]
bracketeer
(do
fd <- openFd' to SPI.WriteOnly dflags $ Just sourceFileMode
handle' <- SPI.fdToHandle fd
pure (fd, handle')
)
(\(_, handle') -> hClose handle')
(\(_, handle') -> do
hClose handle'
case fail' of
-- if we created the file and copying failed, it's
-- safe to clean up
True -> PF.removeLink to
False -> pure ()
)
$ \(_, tH) -> do
hSetBinaryMode fH True
hSetBinaryMode tH True
streamlyCopy (fH, tH)
where
streamlyCopy (fH, tH) =
S.fold (FH.writeChunks tH) $ IFH.toChunksWithBufferOf (256 * 1024) fH
foreign import ccall unsafe "open"
c_open :: CString -> CInt -> Posix.CMode -> IO CInt
open_ :: CString
-> Posix.OpenMode
-> [FD.Flags]
-> Maybe Posix.FileMode
-> IO Posix.Fd
open_ str how optional_flags maybe_mode = do
fd <- c_open str all_flags mode_w
return (Posix.Fd fd)
where
all_flags = FD.unionFlags $ optional_flags ++ [open_mode] ++ creat
(creat, mode_w) = case maybe_mode of
Nothing -> ([],0)
Just x -> ([FD.oCreat], x)
open_mode = case how of
Posix.ReadOnly -> FD.oRdonly
Posix.WriteOnly -> FD.oWronly
Posix.ReadWrite -> FD.oRdwr
-- |Open and optionally create this file. See 'System.Posix.Files'
-- for information on how to use the 'FileMode' type.
--
-- Note that passing @Just x@ as the 4th argument triggers the
-- `oCreat` status flag, which must be set when you pass in `oExcl`
-- to the status flags. Also see the manpage for @open(2)@.
openFd' :: FilePath
-> Posix.OpenMode
-> [FD.Flags] -- ^ status flags of @open(2)@
-> Maybe Posix.FileMode -- ^ @Just x@ => creates the file with the given modes, Nothing => the file must exist.
-> IO Posix.Fd
openFd' name how optional_flags maybe_mode =
withFilePath name $ \str ->
throwErrnoPathIfMinus1Retry "openFd" name $
open_ str how optional_flags maybe_mode
-- |Deletes the given file. Raises `eISDIR`
-- if run on a directory. Does not follow symbolic links.
--
-- Throws:
--
-- - `InappropriateType` for wrong file type (directory)
-- - `NoSuchThing` if the file does not exist
-- - `PermissionDenied` if the directory cannot be read
--
-- Notes: calls `unlink`
deleteFile :: FilePath -> IO ()
deleteFile = removeLink
-- |Recreate a symlink.
--
-- In `Overwrite` copy mode only files and empty directories are deleted.
--
-- Safety/reliability concerns:
--
-- * `Overwrite` mode is inherently non-atomic
--
-- Throws:
--
-- - `InvalidArgument` if source file is wrong type (not a symlink)
-- - `PermissionDenied` if output directory cannot be written to
-- - `PermissionDenied` if source directory cannot be opened
-- - `SameFile` if source and destination are the same file
-- (`HPathIOException`)
--
--
-- Throws in `Strict` mode only:
--
-- - `AlreadyExists` if destination already exists
--
-- Throws in `Overwrite` mode only:
--
-- - `UnsatisfiedConstraints` if destination file is non-empty directory
--
-- Notes:
--
-- - calls `symlink`
recreateSymlink :: FilePath -- ^ the old symlink file
-> FilePath -- ^ destination file
-> Bool -- ^ fail if destination file exists
-> IO ()
recreateSymlink symsource newsym fail' = do
sympoint <- readSymbolicLink symsource
case fail' of
True -> pure ()
False ->
hideError doesNotExistErrorType $ deleteFile newsym
createSymbolicLink sympoint newsym
-- copys files, recreates symlinks, fails on all other types
install :: FilePath -> FilePath -> Bool -> IO ()
install from to fail' = do
fs <- PF.getSymbolicLinkStatus from
decide fs
where
decide fs | PF.isRegularFile fs = copyFile from to fail'
| PF.isSymbolicLink fs = recreateSymlink from to fail'
| otherwise = ioError $ mkIOError illegalOperationErrorType "install: not a regular file or symlink" Nothing (Just from)