Skip to content

Commit

Permalink
Merge branch 'cloexec'
Browse files Browse the repository at this point in the history
  • Loading branch information
hasufell committed May 30, 2024
2 parents d2b5ed2 + 8296101 commit a4a0464
Show file tree
Hide file tree
Showing 8 changed files with 372 additions and 222 deletions.
5 changes: 5 additions & 0 deletions CHANGELOG.md
Original file line number Diff line number Diff line change
@@ -1,5 +1,10 @@
# Revision history for file-io

## 0.1.2 -- 2024-05-27

* expose internals via `.Internal` modules
* add `openFileWithCloseOnExec` and `openExistingFileWithCloseOnExec` to `.Internal` modules wrt [#21](https://github.com/hasufell/file-io/issues/21)

## 0.1.1 -- 2024-01-20

* fix a severe bug on windows, where `readFile` may create a missing file, wrt [#14](https://github.com/hasufell/file-io/issues/14)
Expand Down
164 changes: 12 additions & 152 deletions System/File/OsPath.hs
Original file line number Diff line number Diff line change
@@ -1,6 +1,14 @@
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE BangPatterns #-}
{- |
Module : System.File.OsPath
Copyright : (c) Julian Ospald 2023-2024
License : BSD3
Maintainer : [email protected]
Stability : stable
Portability : portable
This module mimics base API wrt file IO, but using 'OsPath'.
-}
module System.File.OsPath (
openBinaryFile
, withFile
Expand All @@ -18,154 +26,6 @@ module System.File.OsPath (
) where


import qualified System.File.Platform as P

import Prelude ((.), ($), String, IO, ioError, pure, either, const, flip, Maybe(..), fmap, (<$>), id, Bool(..), FilePath, (++), return, show, (>>=))
import GHC.IO (catchException)
import GHC.IO.Exception (IOException(..))
import GHC.IO.Handle (hClose_help)
import GHC.IO.Handle.Internals (debugIO)
import GHC.IO.Handle.Types (Handle__, Handle(..))
import Control.Concurrent.MVar
import Control.Monad (void, when)
import Control.DeepSeq (force)
import Control.Exception (SomeException, try, evaluate, mask, onException)
import System.IO (IOMode(..), hSetBinaryMode, hClose)
import System.IO.Unsafe (unsafePerformIO)
import System.OsPath as OSP
import System.OsString.Internal.Types

import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy as BSL

-- | Like 'openFile', but open the file in binary mode.
-- On Windows, reading a file in text mode (which is the default)
-- will translate CRLF to LF, and writing will translate LF to CRLF.
-- This is usually what you want with text files. With binary files
-- this is undesirable; also, as usual under Microsoft operating systems,
-- text mode treats control-Z as EOF. Binary mode turns off all special
-- treatment of end-of-line and end-of-file characters.
-- (See also 'System.IO.hSetBinaryMode'.)

-- On POSIX systems, 'openBinaryFile' is an /interruptible operation/ as
-- described in "Control.Exception".
openBinaryFile :: OsPath -> IOMode -> IO Handle
openBinaryFile osfp iomode = augmentError "openBinaryFile" osfp $ withOpenFile' osfp iomode True False pure False


-- | Run an action on a file.
--
-- The 'Handle' is automatically closed afther the action.
withFile :: OsPath -> IOMode -> (Handle -> IO r) -> IO r
withFile osfp iomode act = (augmentError "withFile" osfp
$ withOpenFile' osfp iomode False False (try . act) True)
>>= either ioError pure

withBinaryFile :: OsPath -> IOMode -> (Handle -> IO r) -> IO r
withBinaryFile osfp iomode act = (augmentError "withBinaryFile" osfp
$ withOpenFile' osfp iomode True False (try . act) True)
>>= either ioError pure

-- | Run an action on a file.
--
-- The 'Handle' is not automatically closed to allow lazy IO. Use this
-- with caution.
withFile'
:: OsPath -> IOMode -> (Handle -> IO r) -> IO r
withFile' osfp iomode act = (augmentError "withFile'" osfp
$ withOpenFile' osfp iomode False False (try . act) False)
>>= either ioError pure

withBinaryFile'
:: OsPath -> IOMode -> (Handle -> IO r) -> IO r
withBinaryFile' osfp iomode act = (augmentError "withBinaryFile'" osfp
$ withOpenFile' osfp iomode True False (try . act) False)
>>= either ioError pure

-- | The 'readFile' function reads a file and returns the contents of the file
-- as a 'ByteString'. The file is read lazily, on demand.
readFile :: OsPath -> IO BSL.ByteString
readFile fp = withFile' fp ReadMode BSL.hGetContents

-- | The 'readFile'' function reads a file and returns the contents of the file
-- as a 'ByteString'. The file is fully read before being returned.
readFile'
:: OsPath -> IO BS.ByteString
readFile' fp = withFile fp ReadMode BS.hGetContents

-- | The computation 'writeFile' @file str@ function writes the lazy 'ByteString' @str@,
-- to the file @file@.
writeFile :: OsPath -> BSL.ByteString -> IO ()
writeFile fp contents = withFile fp WriteMode (`BSL.hPut` contents)

-- | The computation 'writeFile' @file str@ function writes the strict 'ByteString' @str@,
-- to the file @file@.
writeFile'
:: OsPath -> BS.ByteString -> IO ()
writeFile' fp contents = withFile fp WriteMode (`BS.hPut` contents)

-- | The computation 'appendFile' @file str@ function appends the lazy 'ByteString' @str@,
-- to the file @file@.
appendFile :: OsPath -> BSL.ByteString -> IO ()
appendFile fp contents = withFile fp AppendMode (`BSL.hPut` contents)

-- | The computation 'appendFile' @file str@ function appends the strict 'ByteString' @str@,
-- to the file @file@.
appendFile'
:: OsPath -> BS.ByteString -> IO ()
appendFile' fp contents = withFile fp AppendMode (`BS.hPut` contents)

-- | Open a file and return the 'Handle'.
openFile :: OsPath -> IOMode -> IO Handle
openFile osfp iomode = augmentError "openFile" osfp $ withOpenFile' osfp iomode False False pure False


-- | Open an existing file and return the 'Handle'.
openExistingFile :: OsPath -> IOMode -> IO Handle
openExistingFile osfp iomode = augmentError "openExistingFile" osfp $ withOpenFile' osfp iomode False True pure False


-- ---------------------------------------------------------------------------
-- Internals

handleFinalizer :: FilePath -> MVar Handle__ -> IO ()
handleFinalizer _fp m = do
handle_ <- takeMVar m
(handle_', _) <- hClose_help handle_
putMVar m handle_'
return ()

type HandleFinalizer = FilePath -> MVar Handle__ -> IO ()

-- | Add a finalizer to a 'Handle'. Specifically, the finalizer
-- will be added to the 'MVar' of a file handle or the write-side
-- 'MVar' of a duplex handle. See Handle Finalizers for details.
addHandleFinalizer :: Handle -> HandleFinalizer -> IO ()
addHandleFinalizer hndl finalizer = do
debugIO $ "Registering finalizer: " ++ show filepath
void $ mkWeakMVar mv (finalizer filepath mv)
where
!(filepath, !mv) = case hndl of
FileHandle fp m -> (fp, m)
DuplexHandle fp _ write_m -> (fp, write_m)

withOpenFile' :: OsPath -> IOMode -> Bool -> Bool -> (Handle -> IO r) -> Bool -> IO r
withOpenFile' (OsString fp) iomode binary existing action close_finally = mask $ \restore -> do
hndl <- if existing
then P.openExistingFile fp iomode
else P.openFile fp iomode
addHandleFinalizer hndl handleFinalizer
when binary $ hSetBinaryMode hndl True
r <- restore (action hndl) `onException` hClose hndl
when close_finally $ hClose hndl
pure r

addFilePathToIOError :: String -> OsPath -> IOException -> IOException
addFilePathToIOError fun fp ioe = unsafePerformIO $ do
fp' <- either (const (fmap OSP.toChar . OSP.unpack $ fp)) id <$> try @SomeException (OSP.decodeFS fp)
fp'' <- evaluate $ force fp'
pure $ ioe{ ioe_location = fun, ioe_filename = Just fp'' }

augmentError :: String -> OsPath -> IO a -> IO a
augmentError str osfp = flip catchException (ioError . addFilePathToIOError str osfp)
import System.File.OsPath.Internal
import Prelude ()

175 changes: 175 additions & 0 deletions System/File/OsPath/Internal.hs
Original file line number Diff line number Diff line change
@@ -0,0 +1,175 @@
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE BangPatterns #-}

module System.File.OsPath.Internal where


import qualified System.File.Platform as P

import Prelude ((.), ($), String, IO, ioError, pure, either, const, flip, Maybe(..), fmap, (<$>), id, Bool(..), FilePath, (++), return, show, (>>=))
import GHC.IO (catchException)
import GHC.IO.Exception (IOException(..))
import GHC.IO.Handle (hClose_help)
import GHC.IO.Handle.Internals (debugIO)
import GHC.IO.Handle.Types (Handle__, Handle(..))
import Control.Concurrent.MVar
import Control.Monad (void, when)
import Control.DeepSeq (force)
import Control.Exception (SomeException, try, evaluate, mask, onException)
import System.IO (IOMode(..), hSetBinaryMode, hClose)
import System.IO.Unsafe (unsafePerformIO)
import System.OsPath as OSP
import System.OsString.Internal.Types

import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy as BSL

-- | Like 'openFile', but open the file in binary mode.
-- On Windows, reading a file in text mode (which is the default)
-- will translate CRLF to LF, and writing will translate LF to CRLF.
-- This is usually what you want with text files. With binary files
-- this is undesirable; also, as usual under Microsoft operating systems,
-- text mode treats control-Z as EOF. Binary mode turns off all special
-- treatment of end-of-line and end-of-file characters.
-- (See also 'System.IO.hSetBinaryMode'.)

-- On POSIX systems, 'openBinaryFile' is an /interruptible operation/ as
-- described in "Control.Exception".
openBinaryFile :: OsPath -> IOMode -> IO Handle
openBinaryFile osfp iomode = augmentError "openBinaryFile" osfp $ withOpenFile' osfp iomode True False False pure False


-- | Run an action on a file.
--
-- The 'Handle' is automatically closed afther the action.
withFile :: OsPath -> IOMode -> (Handle -> IO r) -> IO r
withFile osfp iomode act = (augmentError "withFile" osfp
$ withOpenFile' osfp iomode False False False (try . act) True)
>>= either ioError pure

withBinaryFile :: OsPath -> IOMode -> (Handle -> IO r) -> IO r
withBinaryFile osfp iomode act = (augmentError "withBinaryFile" osfp
$ withOpenFile' osfp iomode True False False (try . act) True)
>>= either ioError pure

-- | Run an action on a file.
--
-- The 'Handle' is not automatically closed to allow lazy IO. Use this
-- with caution.
withFile'
:: OsPath -> IOMode -> (Handle -> IO r) -> IO r
withFile' osfp iomode act = (augmentError "withFile'" osfp
$ withOpenFile' osfp iomode False False False (try . act) False)
>>= either ioError pure

withBinaryFile'
:: OsPath -> IOMode -> (Handle -> IO r) -> IO r
withBinaryFile' osfp iomode act = (augmentError "withBinaryFile'" osfp
$ withOpenFile' osfp iomode True False False (try . act) False)
>>= either ioError pure

-- | The 'readFile' function reads a file and returns the contents of the file
-- as a 'ByteString'. The file is read lazily, on demand.
readFile :: OsPath -> IO BSL.ByteString
readFile fp = withFile' fp ReadMode BSL.hGetContents

-- | The 'readFile'' function reads a file and returns the contents of the file
-- as a 'ByteString'. The file is fully read before being returned.
readFile'
:: OsPath -> IO BS.ByteString
readFile' fp = withFile fp ReadMode BS.hGetContents

-- | The computation 'writeFile' @file str@ function writes the lazy 'ByteString' @str@,
-- to the file @file@.
writeFile :: OsPath -> BSL.ByteString -> IO ()
writeFile fp contents = withFile fp WriteMode (`BSL.hPut` contents)

-- | The computation 'writeFile' @file str@ function writes the strict 'ByteString' @str@,
-- to the file @file@.
writeFile'
:: OsPath -> BS.ByteString -> IO ()
writeFile' fp contents = withFile fp WriteMode (`BS.hPut` contents)

-- | The computation 'appendFile' @file str@ function appends the lazy 'ByteString' @str@,
-- to the file @file@.
appendFile :: OsPath -> BSL.ByteString -> IO ()
appendFile fp contents = withFile fp AppendMode (`BSL.hPut` contents)

-- | The computation 'appendFile' @file str@ function appends the strict 'ByteString' @str@,
-- to the file @file@.
appendFile'
:: OsPath -> BS.ByteString -> IO ()
appendFile' fp contents = withFile fp AppendMode (`BS.hPut` contents)

-- | Open a file and return the 'Handle'.
openFile :: OsPath -> IOMode -> IO Handle
openFile osfp iomode = augmentError "openFile" osfp $ withOpenFile' osfp iomode False False False pure False


-- | Open an existing file and return the 'Handle'.
openExistingFile :: OsPath -> IOMode -> IO Handle
openExistingFile osfp iomode = augmentError "openExistingFile" osfp $ withOpenFile' osfp iomode False True False pure False

-- | Open a file and return the 'Handle'.
--
-- Sets @O_CLOEXEC@ on posix.
--
-- @since 0.1.2
openFileWithCloseOnExec :: OsPath -> IOMode -> IO Handle
openFileWithCloseOnExec osfp iomode = augmentError "openFileWithCloseOnExec" osfp $ withOpenFile' osfp iomode False False True pure False


-- | Open an existing file and return the 'Handle'.
--
-- Sets @O_CLOEXEC@ on posix.
--
-- @since 0.1.2
openExistingFileWithCloseOnExec :: OsPath -> IOMode -> IO Handle
openExistingFileWithCloseOnExec osfp iomode = augmentError "openExistingFileWithCloseOnExec" osfp $ withOpenFile' osfp iomode False True True pure False

-- ---------------------------------------------------------------------------
-- Internals

handleFinalizer :: FilePath -> MVar Handle__ -> IO ()
handleFinalizer _fp m = do
handle_ <- takeMVar m
(handle_', _) <- hClose_help handle_
putMVar m handle_'
return ()

type HandleFinalizer = FilePath -> MVar Handle__ -> IO ()

-- | Add a finalizer to a 'Handle'. Specifically, the finalizer
-- will be added to the 'MVar' of a file handle or the write-side
-- 'MVar' of a duplex handle. See Handle Finalizers for details.
addHandleFinalizer :: Handle -> HandleFinalizer -> IO ()
addHandleFinalizer hndl finalizer = do
debugIO $ "Registering finalizer: " ++ show filepath
void $ mkWeakMVar mv (finalizer filepath mv)
where
!(filepath, !mv) = case hndl of
FileHandle fp m -> (fp, m)
DuplexHandle fp _ write_m -> (fp, write_m)

withOpenFile' :: OsPath -> IOMode -> Bool -> Bool -> Bool -> (Handle -> IO r) -> Bool -> IO r
withOpenFile' (OsString fp) iomode binary existing cloExec action close_finally = mask $ \restore -> do
hndl <- case (existing, cloExec) of
(True, False) -> P.openExistingFile fp iomode
(False, False) -> P.openFile fp iomode
(True, True) -> P.openExistingFileWithCloseOnExec fp iomode
(False, True) -> P.openFileWithCloseOnExec fp iomode
addHandleFinalizer hndl handleFinalizer
when binary $ hSetBinaryMode hndl True
r <- restore (action hndl) `onException` hClose hndl
when close_finally $ hClose hndl
pure r

addFilePathToIOError :: String -> OsPath -> IOException -> IOException
addFilePathToIOError fun fp ioe = unsafePerformIO $ do
fp' <- either (const (fmap OSP.toChar . OSP.unpack $ fp)) id <$> try @SomeException (OSP.decodeFS fp)
fp'' <- evaluate $ force fp'
pure $ ioe{ ioe_location = fun, ioe_filename = Just fp'' }

augmentError :: String -> OsPath -> IO a -> IO a
augmentError str osfp = flip catchException (ioError . addFilePathToIOError str osfp)

Loading

0 comments on commit a4a0464

Please sign in to comment.