{-# LANGUAGE BangPatterns #-} {-# LANGUAGE MultiWayIf #-} {-# LANGUAGE CPP #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE ScopedTypeVariables #-} {-| Module : Std.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 Std.IO.FileSystem ( -- * regular file devices UVFile , UVFileReader, newUVFileReader, peekUVFileReader , UVFileWriter, newUVFileWriter, peekUVFileWriter , initUVFile -- * opening constant , UVFileMode(DEFAULT_MODE, S_IRWXU, S_IRUSR, S_IWUSR , S_IXUSR, S_IRWXG, S_IRGRP, S_IWGRP, S_IXGRP, S_IRWXO, S_IROTH ) , UVFileFlag(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.Concurrent.STM.TVar import Control.Concurrent.MVar import Control.Monad import Control.Monad.STM import Data.Word import Data.Int import Std.Data.CBytes as CBytes import Foreign.Ptr import Foreign.Storable (peekElemOff) import Foreign.Marshal.Alloc (allocaBytes) import Std.Foreign.PrimArray (withPrimSafe', withPrimUnsafe') import Std.IO.Buffered import Std.IO.Exception import Std.IO.Resource import Std.IO.UV.Errno import Std.IO.UV.FFI import Std.IO.UV.Manager -------------------------------------------------------------------------------- -- File -- | 'UVFile' wrap a @uv_file_t@ and a referencing counter. -- -- libuv implements read and write method with both implict and explict offset capable. -- (negative offset result in @read/write@ system call otherwise @pread/pwrite@), we provide -- implict offset interface with 'UVFile', which is NOT thread safe. -- -- An offset bundled 'UVFileReader', 'UVFileWriter' is also provided, which can be used -- concurrently. The offset is protected with 'MVar' and increasing automatically. data UVFile = UVFile { uvfFD :: {-# UNPACK #-} !UVFD , uvfCounter :: {-# UNPACK #-} !(TVar Int) } instance Show UVFile where show (UVFile fd _) = "Std.IO.FileSystem: UVFile" ++ show fd instance Input UVFile where -- readInput :: HasCallStack => UVFile -> Ptr Word8 -> Int -> IO Int -- use -1 offset to use fd's default offset readInput f buf bufSiz = readUVFile f buf bufSiz (-1) readUVFile :: HasCallStack => UVFile -> Ptr Word8 -> Int -> Int64 -> IO Int readUVFile (UVFile fd counter) buf bufSiz off = bracket_ (atomically $ do s <- readTVar counter if s >= 0 then modifyTVar' counter (+1) else throwECLOSEDSTM) (atomically $ modifyTVar' counter (subtract 1)) (throwUVIfMinus $ hs_uv_fs_read fd buf bufSiz off) instance Output UVFile where -- use -1 offset to use fd's default offset writeOutput f buf bufSiz = writeUVFile f buf bufSiz (-1) writeUVFile :: HasCallStack => UVFile -> Ptr Word8 -> Int -> Int64 -> IO () writeUVFile (UVFile fd counter) buf bufSiz off = bracket_ (atomically $ do s <- readTVar counter if s >= 0 then modifyTVar' counter (+1) else throwECLOSEDSTM) (atomically $ modifyTVar' counter (subtract 1)) (if off == -1 then go buf bufSiz else go' buf bufSiz off) where go !buf !bufSiz = do written <- throwUVIfMinus (hs_uv_fs_write fd buf bufSiz (-1)) when (written < bufSiz) (go (buf `plusPtr` written) (bufSiz-written)) go' !buf !bufSiz !off = do written <- throwUVIfMinus (hs_uv_fs_write fd buf bufSiz off) when (written < bufSiz) $ go' (buf `plusPtr` written) (bufSiz-written) (off+fromIntegral written) -- | An 'UVFile' bundled with a 'MVar' protected reading offset. data UVFileReader = UVFileReader {-# UNPACK #-} !UVFile {-# UNPACK #-} !(MVar Int64) -- | Create a reader from an 'UVFile'. -- -- Note this will not increase 'UVFile''s referencing counter. newUVFileReader :: UVFile -- ^ the file we're reading -> Int64 -- ^ initial reading offset -> IO UVFileReader newUVFileReader uvf off = UVFileReader uvf <$> newMVar off -- | Change reader's offset. peekUVFileReader :: UVFileReader -> Int64 -- ^ the new offset -> IO Int64 -- ^ the old offset peekUVFileReader (UVFileReader _ offsetLock) = swapMVar offsetLock instance Input UVFileReader where readInput (UVFileReader file offsetLock) buf bufSiz = modifyMVar offsetLock $ \ off -> do !l <- readUVFile file buf bufSiz off let !off' = off + fromIntegral l return (off', l) -- | An 'UVFile' bundled with a 'MVar' protected writing offset. data UVFileWriter = UVFileWriter {-# UNPACK #-} !UVFile {-# UNPACK #-} !(MVar Int64) -- | Create a writer from an 'UVFile'. -- -- Note this will not increase 'UVFile''s referencing counter. newUVFileWriter :: UVFile -- ^ the file we're writing -> Int64 -- ^ initial writing offset -> IO UVFileWriter newUVFileWriter uvf off = UVFileWriter uvf <$> newMVar off -- | Change writer's offset. peekUVFileWriter :: UVFileWriter -> Int64 -- ^ the new offset -> IO Int64 -- ^ the old offset peekUVFileWriter (UVFileWriter _ offsetLock) = swapMVar offsetLock instance Output UVFileWriter where writeOutput (UVFileWriter file offsetLock) buf bufSiz = modifyMVar_ offsetLock $ \ off -> do writeUVFile file buf bufSiz off let !off' = off + fromIntegral bufSiz return off' -------------------------------------------------------------------------------- -- | 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. -- -- Note, 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. initUVFile :: HasCallStack => CBytes -> UVFileFlag -- ^ Opening flags, e.g. 'O_CREAT' @.|.@ 'O_RDWR' -> UVFileMode -- ^ Sets the file mode (permission and sticky bits), -- but only if the file was created, see 'DEFAULT_MODE'. -> Resource UVFile initUVFile path flags mode = initResource (do fd <- withCBytes path $ \ p -> throwUVIfMinus $ hs_uv_fs_open p flags mode counter <- newTVarIO 0 return (UVFile fd counter)) (\ (UVFile fd counter) -> join . atomically $ do s <- readTVar counter case s `compare` 0 of GT -> retry -- don't close until no one is using it EQ -> do swapTVar counter (-1) return (void $ hs_uv_fs_close fd) LT -> return (return ())) -------------------------------------------------------------------------------- -- | Equivalent to . -- -- Note mode is currently not implemented on Windows. mkdir :: HasCallStack => CBytes -> UVFileMode -> 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 uvm <- getUVManager bracket (withCBytes path $ \ p -> withPrimUnsafe' $ \ 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 (path, typ) <- peekUVDirEnt dent let !typ' = fromUVDirEntType typ !path' <- fromCString path return (path', typ')) -------------------------------------------------------------------------------- -- | Equivalent to stat :: HasCallStack => CBytes -> IO UVStat stat path = do withCBytes path $ \ p -> allocaBytes uvStatSize $ \ stat -> do throwUVIfMinus_ (hs_uv_fs_stat p stat) peekUVStat stat -- | Equivalent to lstat :: HasCallStack => CBytes -> IO UVStat lstat path = do withCBytes path $ \ p -> allocaBytes uvStatSize $ \ stat -> do throwUVIfMinus_ (hs_uv_fs_lstat p stat) peekUVStat stat -- | Equivalent to fstat :: HasCallStack => UVFile -> IO UVStat fstat (UVFile fd counter) = bracket_ (atomically $ do s <- readTVar counter if s >= 0 then modifyTVar' counter (+1) else throwECLOSEDSTM) (atomically $ modifyTVar' counter (subtract 1)) (allocaBytes uvStatSize $ \ stat -> do throwUVIfMinus_ (hs_uv_fs_fstat fd stat) peekUVStat stat) -------------------------------------------------------------------------------- -- | 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 => UVFile -> IO () fsync (UVFile fd counter) = bracket_ (atomically $ do s <- readTVar counter if s >= 0 then modifyTVar' counter (+1) else throwECLOSEDSTM) (atomically $ modifyTVar' counter (subtract 1)) (throwUVIfMinus_ (hs_uv_fs_fsync fd)) -- | Equivalent to . fdatasync :: HasCallStack => UVFile -> IO () fdatasync (UVFile fd counter) = bracket_ (atomically $ do s <- readTVar counter if s >= 0 then modifyTVar' counter (+1) else throwECLOSEDSTM) (atomically $ modifyTVar' counter (subtract 1)) (throwUVIfMinus_ (hs_uv_fs_fdatasync fd)) -- | Equivalent to . ftruncate :: HasCallStack => UVFile -> Int64 -> IO () ftruncate (UVFile fd counter) off = bracket_ (atomically $ do s <- readTVar counter if s >= 0 then modifyTVar' counter (+1) else throwECLOSEDSTM) (atomically $ modifyTVar' counter (subtract 1)) (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 -> UVFileMode -> IO () chmod path mode = throwUVIfMinus_ . withCBytes path $ \ p -> hs_uv_fs_chmod p mode -- | Equivalent to . fchmod :: HasCallStack => UVFile -> UVFileMode -> IO () fchmod (UVFile fd counter) mode = bracket_ (atomically $ do s <- readTVar counter if s >= 0 then modifyTVar' counter (+1) else throwECLOSEDSTM) (atomically $ modifyTVar' counter (subtract 1)) (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 => UVFile -> Double -> Double -> IO () futime (UVFile fd counter) atime mtime = bracket_ (atomically $ do s <- readTVar counter if s >= 0 then modifyTVar' counter (+1) else throwECLOSEDSTM) (atomically $ modifyTVar' counter (subtract 1)) (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 uvm <- getUVManager bracket (withCBytes path $ \ p -> withPrimUnsafe' $ \ p' -> throwUVIfMinus (hs_uv_fs_readlink p p')) (\ (path, _) -> hs_uv_fs_readlink_cleanup path) (\ (path, _) -> do !path' <- fromCString path return path') -- | 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 -> withPrimUnsafe' $ \ p' -> throwUVIfMinus (hs_uv_fs_realpath p p')) (\ (path, _) -> hs_uv_fs_readlink_cleanup path) (\ (path, _) -> do !path' <- fromCString path return path')