{-# LANGUAGE BangPatterns #-} {-# LANGUAGE MultiWayIf #-} {-# LANGUAGE CPP #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE ScopedTypeVariables #-} {-| Module : Z.IO.FileSystem Description : Filesystem IO Copyright : (c) Dong Han, 2017~2019 License : BSD Maintainer : winterland1989@gmail.com Stability : experimental Portability : non-portable This module provide IO operations related to filesystem, operations are implemented using unsafe FFIs, which should be prefered when the operations' estimated time is short(<1ms), which is much common on modern SSDs. -} module Z.IO.FileSystem ( -- * regular file devices File, initFile, readFile, writeFile -- * opening constant , FileMode(DEFAULT_MODE, S_IRWXU, S_IRUSR, S_IWUSR , S_IXUSR, S_IRWXG, S_IRGRP, S_IWGRP, S_IXGRP, S_IRWXO, S_IROTH ) , FileFlag(O_APPEND, O_CREAT, O_DIRECT, O_DSYNC, O_EXCL , O_EXLOCK, O_NOATIME, O_NOFOLLOW, O_RDONLY, O_RDWR, O_SYMLINK , O_SYNC, O_TRUNC, O_WRONLY, O_RANDOM, O_SHORT_LIVED, O_SEQUENTIAL, O_TEMPORARY ) -- * filesystem operations , mkdir , unlink , mkdtemp , rmdir , DirEntType(..) , scandir , UVStat(..), UVTimeSpec(..) , stat, lstat, fstat , rename , fsync, fdatasync , ftruncate , UVCopyFileFlag(COPYFILE_DEFAULT, COPYFILE_EXCL, COPYFILE_FICLONE) , copyfile , UVAccessMode(F_OK, R_OK, W_OK, X_OK) , AccessResult(..) , access , chmod, fchmod , utime, futime , UVSymlinkFlag(SYMLINK_DEFAULT, SYMLINK_DIR, SYMLINK_JUNCTION) , link, symlink , readlink, realpath ) where import Control.Monad import Data.Word import Data.Int import Data.IORef import Foreign.Ptr import Foreign.Storable (peekElemOff) import Foreign.Marshal.Alloc (allocaBytes) import Z.Data.CBytes as CBytes import Z.Foreign import Z.IO.Buffered import Z.IO.Exception import Z.IO.Resource import Z.IO.UV.Errno import Z.IO.UV.FFI import Prelude hiding (writeFile, readFile) -------------------------------------------------------------------------------- -- File -- | 'File' and its operations are NOT thread safe, use 'MVar' 'File' in multiple threads -- -- libuv implements read and write method with both implict and explict offset capable. -- Implict offset interface is provided by 'Input' \/ 'Output' instances. -- Explict offset interface is provided by 'readFile' \/ 'writeFile'. -- data File = File {-# UNPACK #-} !UVFD -- ^ the file {-# UNPACK #-} !(IORef Bool) -- ^ closed flag -- | If fd is -1 (closed), throw 'ResourceVanished' ECLOSED. checkFileClosed :: HasCallStack => File -> (UVFD -> IO a) -> IO a checkFileClosed (File fd closedRef) f = do closed <- readIORef closedRef if closed then throwECLOSED else f fd instance Input File where -- readInput :: HasCallStack => File -> Ptr Word8 -> Int -> IO Int -- use -1 offset to use fd's default offset readInput f buf bufSiz = readFile f buf bufSiz (-1) -- | Read file with given offset -- -- Read length may be smaller than buffer size. readFile :: HasCallStack => File -> Ptr Word8 -- ^ buffer -> Int -- ^ buffer size -> Int64 -- ^ file offset, pass -1 to use default(system) offset -> IO Int -- ^ read length readFile uvf buf bufSiz off = checkFileClosed uvf $ \ fd -> throwUVIfMinus $ hs_uv_fs_read fd buf bufSiz off instance Output File where writeOutput f buf bufSiz = writeFile f buf bufSiz (-1) -- | Write buffer to file -- -- This function will loop until all bytes are written. writeFile :: HasCallStack => File -> Ptr Word8 -- ^ buffer -> Int -- ^ buffer size -> Int64 -- ^ file offset, pass -1 to use default(system) offset -> IO () writeFile uvf buf0 bufSiz0 off0 = checkFileClosed uvf $ \fd -> if off0 == -1 then go fd buf0 bufSiz0 else go' fd buf0 bufSiz0 off0 where go fd !buf !bufSiz = do written <- throwUVIfMinus (hs_uv_fs_write fd buf bufSiz (-1)) when (written < bufSiz) (go fd (buf `plusPtr` written) (bufSiz-written)) go' fd !buf !bufSiz !off = do written <- throwUVIfMinus (hs_uv_fs_write fd buf bufSiz off) when (written < bufSiz) $ go' fd (buf `plusPtr` written) (bufSiz-written) (off+fromIntegral written) -------------------------------------------------------------------------------- -- | init a file 'Resource', which open a file when used. -- -- Resource closing is thread safe, on some versions of OSX, repeatly open and close same file 'Resource' may -- result in shared memory object error, use 'O_CREAT' to avoid that. initFile :: HasCallStack => CBytes -> FileFlag -- ^ Opening flags, e.g. 'O_CREAT' @.|.@ 'O_RDWR' -> FileMode -- ^ Sets the file mode (permission and sticky bits), -- but only if the file was created, see 'DEFAULT_MODE'. -> Resource File initFile path flags mode = initResource (do !fd <- withCBytes path $ \ p -> throwUVIfMinus $ hs_uv_fs_open p flags mode File fd <$> newIORef False) (\ (File fd closedRef) -> do closed <- readIORef closedRef unless closed $ do throwUVIfMinus_ (hs_uv_fs_close fd) writeIORef closedRef True) -------------------------------------------------------------------------------- -- | Equivalent to . -- -- Note mode is currently not implemented on Windows. mkdir :: HasCallStack => CBytes -> FileMode -> IO () mkdir path mode = throwUVIfMinus_ . withCBytes path $ \ p -> hs_uv_fs_mkdir p mode -- | Equivalent to . unlink :: HasCallStack => CBytes -> IO () unlink path = throwUVIfMinus_ (withCBytes path hs_uv_fs_unlink) -- | Equivalent to -- -- Creates a temporary directory in the most secure manner possible. -- There are no race conditions in the directory’s creation. -- The directory is readable, writable, and searchable only by the creating user ID. -- The user of mkdtemp() is responsible for deleting the temporary directory and -- its contents when done with it. -- -- Note: the argument is the prefix of the temporary directory, -- so no need to add XXXXXX ending. -- mkdtemp :: HasCallStack => CBytes -> IO CBytes mkdtemp path = do let size = CBytes.length path withCBytes path $ \ p -> CBytes.create (size+7) $ \ p' -> do -- we append "XXXXXX\NUL" in C throwUVIfMinus_ (hs_uv_fs_mkdtemp p size p') return (size+6) -- | Equivalent to . rmdir :: HasCallStack => CBytes -> IO () rmdir path = throwUVIfMinus_ (withCBytes path hs_uv_fs_rmdir) -- | Equivalent to . -- -- Note Unlike scandir(3), this function does not return the “.” and “..” entries. -- -- Note On Linux, getting the type of an entry is only supported by some file systems (btrfs, ext2, ext3 and ext4 at the time of this writing), check the man page. scandir :: HasCallStack => CBytes -> IO [(CBytes, DirEntType)] scandir path = do bracket (withCBytes path $ \ p -> allocPrimUnsafe $ \ dents -> throwUVIfMinus (hs_uv_fs_scandir p dents)) (\ (dents, n) -> hs_uv_fs_scandir_cleanup dents n) (\ (dents, n) -> forM [0..n-1] $ \ i -> do dent <- peekElemOff dents i (p, typ) <- peekUVDirEnt dent let !typ' = fromUVDirEntType typ !p' <- fromCString p return (p', typ')) -------------------------------------------------------------------------------- -- | Equivalent to stat :: HasCallStack => CBytes -> IO UVStat stat path = withCBytes path $ \ p -> allocaBytes uvStatSize $ \ s -> do throwUVIfMinus_ (hs_uv_fs_stat p s) peekUVStat s -- | Equivalent to lstat :: HasCallStack => CBytes -> IO UVStat lstat path = withCBytes path $ \ p -> allocaBytes uvStatSize $ \ s -> do throwUVIfMinus_ (hs_uv_fs_lstat p s) peekUVStat s -- | Equivalent to fstat :: HasCallStack => File -> IO UVStat fstat uvf = checkFileClosed uvf $ \ fd -> allocaBytes uvStatSize $ \ s -> do throwUVIfMinus_ (hs_uv_fs_fstat fd s) peekUVStat s -------------------------------------------------------------------------------- -- | Equivalent to . -- -- Note On Windows if this function fails with UV_EBUSY, UV_EPERM or UV_EACCES, it will retry to rename the file up to four times with 250ms wait between attempts before giving up. If both path and new_path are existing directories this function will work only if target directory is empty. rename :: HasCallStack => CBytes -> CBytes -> IO () rename path path' = throwUVIfMinus_ . withCBytes path $ \ p -> withCBytes path' (hs_uv_fs_rename p) -- | Equivalent to . fsync :: HasCallStack => File -> IO () fsync uvf = checkFileClosed uvf $ \ fd -> throwUVIfMinus_ $ hs_uv_fs_fsync fd -- | Equivalent to . fdatasync :: HasCallStack => File -> IO () fdatasync uvf = checkFileClosed uvf $ \ fd -> throwUVIfMinus_ $ hs_uv_fs_fdatasync fd -- | Equivalent to . ftruncate :: HasCallStack => File -> Int64 -> IO () ftruncate uvf off = checkFileClosed uvf $ \ fd -> throwUVIfMinus_ $ hs_uv_fs_ftruncate fd off -- | Copies a file from path to new_path. -- -- Warning: If the destination path is created, but an error occurs while copying the data, then the destination path is removed. There is a brief window of time between closing and removing the file where another process could access the file. copyfile :: HasCallStack => CBytes -> CBytes -> UVCopyFileFlag -> IO () copyfile path path' flag = throwUVIfMinus_ . withCBytes path $ \ p -> withCBytes path' $ \ p' -> hs_uv_fs_copyfile p p' flag -- | Equivalent to on Unix. -- Windows uses GetFileAttributesW(). access :: HasCallStack => CBytes -> UVAccessMode -> IO AccessResult access path mode = do r <- withCBytes path $ \ p -> fromIntegral <$> hs_uv_fs_access p mode if | r == 0 -> return AccessOK | r == UV_ENOENT -> return NoExistence | r == UV_EACCES -> return NoPermission | otherwise -> do name <- uvErrName r desc <- uvStdError r throwUVError r (IOEInfo name desc callStack) -- | Equivalent to . chmod :: HasCallStack => CBytes -> FileMode -> IO () chmod path mode = throwUVIfMinus_ . withCBytes path $ \ p -> hs_uv_fs_chmod p mode -- | Equivalent to . fchmod :: HasCallStack => File -> FileMode -> IO () fchmod uvf mode = checkFileClosed uvf $ \ fd -> throwUVIfMinus_ $ hs_uv_fs_fchmod fd mode -- | Equivalent to . -- -- libuv choose 'Double' type due to cross platform concerns, we only provide micro-second precision: -- -- * second = v -- * nanosecond = (v * 1000000) % 1000000 * 1000; -- -- second and nanosecond are fields in 'UVTimeSpec' respectively. -- -- Note libuv prior to v1.23.1 have issues which may result in nanosecond not set, 'futime' doesn't have -- that issue. utime :: HasCallStack => CBytes -> Double -- ^ atime, i.e. access time -> Double -- ^ mtime, i.e. modify time -> IO () utime path atime mtime = throwUVIfMinus_ . withCBytes path $ \ p -> hs_uv_fs_utime p atime mtime -- | Equivalent to . -- -- Same precision notes with 'utime'. futime :: HasCallStack => File -> Double -> Double -> IO () futime uvf atime mtime = checkFileClosed uvf $ \ fd -> throwUVIfMinus_ (hs_uv_fs_futime fd atime mtime) -- | Equivalent to . link :: HasCallStack => CBytes -> CBytes -> IO () link path path' = throwUVIfMinus_ . withCBytes path $ \ p -> withCBytes path' $ hs_uv_fs_link p -- | Equivalent to . -- -- | Note On Windows the flags parameter can be specified to control how the symlink will be created. -- -- * 'SYMLINK_DIR': indicates that path points to a directory. -- * 'SYMLINK_JUNCTION': request that the symlink is created using junction points. -- -- On other platforms these flags are ignored. symlink :: HasCallStack => CBytes -> CBytes -> UVSymlinkFlag -> IO () symlink path path' flag = throwUVIfMinus_ . withCBytes path $ \ p -> withCBytes path' $ \ p' -> hs_uv_fs_symlink p p' flag -- | Equivalent to . readlink :: HasCallStack => CBytes -> IO CBytes readlink path = do bracket (withCBytes path $ \ p -> allocPrimUnsafe $ \ p' -> throwUVIfMinus (hs_uv_fs_readlink p p')) (hs_uv_fs_readlink_cleanup . fst) (fromCString . fst) -- | Equivalent to on Unix. Windows uses . -- -- Warning This function has certain platform-specific caveats that were discovered when used in Node. -- -- * macOS and other BSDs: this function will fail with UV_ELOOP if more than 32 symlinks are found while -- resolving the given path. This limit is hardcoded and cannot be sidestepped. -- -- * Windows: while this function works in the common case, there are a number of corner cases where it doesn’t: -- -- * Paths in ramdisk volumes created by tools which sidestep the Volume Manager (such as ImDisk) cannot be resolved. -- * Inconsistent casing when using drive letters. -- * Resolved path bypasses subst’d drives. -- -- While this function can still be used, it’s not recommended if scenarios such as the above need to be supported. -- The background story and some more details on these issues can be checked . -- -- Note This function is not implemented on Windows XP and Windows Server 2003. On these systems, UV_ENOSYS is returned. realpath :: HasCallStack => CBytes -> IO CBytes realpath path = do bracket (withCBytes path $ \ p -> allocPrimUnsafe $ \ p' -> throwUVIfMinus (hs_uv_fs_realpath p p')) (hs_uv_fs_readlink_cleanup . fst) (fromCString . fst)