{-# LANGUAGE BangPatterns #-} {-# LANGUAGE CPP #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE ScopedTypeVariables #-} {-| Module : Z.IO.FileSystem.Threaded Description : Filesystem IO using threadpool 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 libuv's threadpool to achieve non-block behavior (non-block here meaning won't block other haskell threads), which should be prefered when the operations' estimated time is long enough(>1ms) or running with a non-threaded haskell runtime, such as accessing network filesystem or scan a very large directory. Otherwise you may block RTS's capability thus all the other haskell threads live on it. The threadpool version operations have overheads similar to safe FFI, but provide same adventages: * The libuv's threadpool have a limit on concurrent threads number (4 by default), which can reduce disk contention. * The threadpool version works with non-threaded runtime, which doesn't have safe FFI available. * The threadpool version won't relinquish current HEC (Haskell Execution Context) a.k.a. capability. -} module Z.IO.FileSystem.Threaded ( -- * regular file devices FileT, checkFileTClosed , initFileT, readFileT, writeFileT -- * 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 Z.Data.CBytes as CBytes import Foreign.Ptr import Foreign.Storable (peekElemOff) import Foreign.Marshal.Alloc (allocaBytes) 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 Z.IO.UV.Manager -------------------------------------------------------------------------------- -- File -- | 'FileT' and its operations are NOT thread safe, use 'MVar' 'FileT' in multiple threads. -- -- Note this is a differet data type from "Z.IO.FileSystem" \'s one, the 'Input' -- and 'Output' instance use thread pool version functions. -- -- 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 'readFileT' \/ 'writeFileT'. -- data FileT = FileT {-# UNPACK #-} !UVFD -- ^ the file {-# UNPACK #-} !(IORef Bool) -- ^ closed flag -- | If fd is -1 (closed), throw 'ResourceVanished' ECLOSED. checkFileTClosed :: HasCallStack => FileT -> (UVFD -> IO a) -> IO a checkFileTClosed (FileT fd closedRef) f = do closed <- readIORef closedRef if closed then throwECLOSED else f fd instance Input FileT where readInput f buf bufSiz = readFileT f buf bufSiz (-1) -- | Read file with given offset -- -- Read length may be smaller than buffer size. readFileT :: HasCallStack => FileT -> Ptr Word8 -- ^ buffer -> Int -- ^ buffer size -> Int64 -- ^ file offset, pass -1 to use default(system) offset -> IO Int -- ^ read length readFileT uvf buf bufSiz off = checkFileTClosed uvf $ \ fd -> do uvm <- getUVManager withUVRequest uvm (hs_uv_fs_read_threaded fd buf bufSiz off) instance Output FileT where writeOutput f buf bufSiz = writeFileT f buf bufSiz (-1) -- | Write buffer to file -- -- This function will loop until all bytes are written. writeFileT :: HasCallStack => FileT -> Ptr Word8 -- ^ buffer -> Int -- ^ buffer size -> Int64 -- ^ file offset, pass -1 to use default(system) offset -> IO () writeFileT uvf buf0 bufSiz0 off0 = checkFileTClosed uvf $ \ fd -> do (if off0 == -1 then go fd buf0 bufSiz0 else go' fd buf0 bufSiz0 off0) where -- use -1 offset to use fd's default offset go fd buf bufSiz = do uvm <- getUVManager written <- withUVRequest uvm (hs_uv_fs_write_threaded fd buf bufSiz (-1)) when (written < bufSiz) (go fd (buf `plusPtr` written) (bufSiz-written)) go' fd buf bufSiz !off = do uvm <- getUVManager written <- withUVRequest uvm (hs_uv_fs_write_threaded 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 will wait for the referencing counter goes -- down to zero (no reading or writing is in process), which can -- be a problem if you are using multiple readers or writers in multiple threads. -- In that case you have to stop all reading or writing thread if you don't want to -- block the resource thread. initFileT :: 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 FileT initFileT path flags mode = initResource (do uvm <- getUVManager fd <- withCBytes path $ \ p -> withUVRequest uvm (hs_uv_fs_open_threaded p flags mode) FileT (fromIntegral fd) <$> newIORef False) (\ (FileT 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 = do uvm <- getUVManager withCBytes path $ \ p -> withUVRequest_ uvm (hs_uv_fs_mkdir_threaded p mode) -- | Equivalent to . unlink :: HasCallStack => CBytes -> IO () unlink path = do uvm <- getUVManager withCBytes path $ \ p -> withUVRequest_ uvm (hs_uv_fs_unlink_threaded p) -- | 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 uvm <- getUVManager withUVRequest_ uvm (hs_uv_fs_mkdtemp_threaded p size p') return (size+6) -- | Equivalent to . rmdir :: HasCallStack => CBytes -> IO () rmdir path = do uvm <- getUVManager withCBytes path (void . withUVRequest uvm . hs_uv_fs_rmdir_threaded) -------------------------------------------------------------------------------- -- | 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 uvm <- getUVManager bracket (withCBytes path $ \ p -> allocPrimSafe $ \ dents -> withUVRequestEx uvm (hs_uv_fs_scandir_threaded p dents) (hs_uv_fs_scandir_extra_cleanup 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 = do withCBytes path $ \ p -> allocaBytes uvStatSize $ \ s -> do uvm <- getUVManager withUVRequest_ uvm (hs_uv_fs_stat_threaded p s) peekUVStat s -- | Equivalent to lstat :: HasCallStack => CBytes -> IO UVStat lstat path = withCBytes path $ \ p -> allocaBytes uvStatSize $ \ s -> do uvm <- getUVManager withUVRequest_ uvm (hs_uv_fs_lstat_threaded p s) peekUVStat s -- | Equivalent to fstat :: HasCallStack => FileT -> IO UVStat fstat uvf = checkFileTClosed uvf $ \ fd -> (allocaBytes uvStatSize $ \ s -> do uvm <- getUVManager withUVRequest_ uvm (hs_uv_fs_fstat_threaded 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' = do uvm <- getUVManager withCBytes path $ \ p -> withCBytes path' $ \ p' -> withUVRequest_ uvm (hs_uv_fs_rename_threaded p p') -- | Equivalent to . fsync :: HasCallStack => FileT -> IO () fsync uvf = checkFileTClosed uvf $ \ fd -> do uvm <- getUVManager withUVRequest_ uvm (hs_uv_fs_fsync_threaded fd) -- | Equivalent to . fdatasync :: HasCallStack => FileT -> IO () fdatasync uvf = checkFileTClosed uvf $ \ fd -> do uvm <- getUVManager withUVRequest_ uvm (hs_uv_fs_fdatasync_threaded fd) -- | Equivalent to . ftruncate :: HasCallStack => FileT -> Int64 -> IO () ftruncate uvf off = checkFileTClosed uvf $ \ fd -> do uvm <- getUVManager withUVRequest_ uvm (hs_uv_fs_ftruncate_threaded 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 = do uvm <- getUVManager withCBytes path $ \ p -> withCBytes path' $ \ p' -> withUVRequest_ uvm (hs_uv_fs_copyfile_threaded p p' flag) -- | Equivalent to on Unix. -- Windows uses GetFileAttributesW(). access :: HasCallStack => CBytes -> UVAccessMode -> IO AccessResult access path mode = do uvm <- getUVManager withCBytes path $ \ p -> withUVRequest' uvm (hs_uv_fs_access_threaded p mode) (handleResult . fromIntegral) where handleResult r | 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 = do uvm <- getUVManager withCBytes path $ \ p -> withUVRequest_ uvm (hs_uv_fs_chmod_threaded p mode) -- | Equivalent to . fchmod :: HasCallStack => FileT -> FileMode -> IO () fchmod uvf mode = checkFileTClosed uvf $ \ fd -> do uvm <- getUVManager withUVRequest_ uvm (hs_uv_fs_fchmod_threaded 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 utime :: HasCallStack => CBytes -> Double -- ^ atime, i.e. access time -> Double -- ^ mtime, i.e. modify time -> IO () utime path atime mtime = do uvm <- getUVManager withCBytes path $ \ p -> withUVRequest_ uvm (hs_uv_fs_utime_threaded p atime mtime) -- | Equivalent to . -- -- Same precision notes with 'utime'. futime :: HasCallStack => FileT -> Double -> Double -> IO () futime uvf atime mtime = checkFileTClosed uvf $ \ fd -> do uvm <- getUVManager withUVRequest_ uvm (hs_uv_fs_futime_threaded fd atime mtime) -- | Equivalent to . link :: HasCallStack => CBytes -> CBytes -> IO () link path path' = do uvm <- getUVManager withCBytes path $ \ p -> withCBytes path' $ \ p' -> withUVRequest_ uvm (hs_uv_fs_link_threaded p 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 = do uvm <- getUVManager withCBytes path $ \ p -> withCBytes path' $ \ p' -> withUVRequest_ uvm (hs_uv_fs_symlink_threaded p p' flag) -- | Equivalent to . readlink :: HasCallStack => CBytes -> IO CBytes readlink path = do uvm <- getUVManager bracket (withCBytes path $ \ p -> allocPrimSafe $ \ p' -> withUVRequestEx uvm (hs_uv_fs_readlink_threaded p p') (\ _ -> hs_uv_fs_readlink_extra_cleanup 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 uvm <- getUVManager bracket (withCBytes path $ \ p -> allocPrimSafe $ \ p' -> withUVRequestEx uvm (hs_uv_fs_realpath_threaded p p') (\ _ -> hs_uv_fs_readlink_extra_cleanup p')) (hs_uv_fs_readlink_cleanup . fst) (fromCString . fst)