Add IO modules, previously from HSFM
This commit is contained in:
766
src/HPath/IO.hs
766
src/HPath/IO.hs
@@ -1,28 +1,778 @@
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-- |
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-- Module : HPath.IO
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-- Copyright : © 2016 Julian Ospald
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-- License : BSD 3 clause
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-- License : GPL-2
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--
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-- Maintainer : Julian Ospald <hasufell@posteo.de>
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-- Stability : experimental
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-- Portability : portable
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--
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-- IO operations on HPath.
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-- This module provides high-level IO related file operations like
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-- copy, delete, move and so on. It only operates on `Path Abs` which
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-- guarantees us well-typed paths which are absolute.
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--
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-- Some functions are just path-safe wrappers around
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-- unix functions, others have stricter exception handling
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-- and some implement functionality that doesn't have a unix
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-- counterpart (like `copyDirRecursive`).
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--
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-- Some of these operations are due to their nature not _atomic_, which
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-- means they may do multiple syscalls which form one context. Some
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-- of them also have to examine the filetypes explicitly before the
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-- syscalls, so a reasonable decision can be made. That means
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-- the result is undefined if another process changes that context
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-- while the non-atomic operation is still happening. However, where
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-- possible, as few syscalls as possible are used and the underlying
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-- exception handling is kept.
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{-# LANGUAGE PackageImports #-}
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{-# LANGUAGE OverloadedStrings #-}
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{-# OPTIONS_HADDOCK ignore-exports #-}
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module HPath.IO
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module HPath.IO where
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import Control.Exception
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(
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bracket
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, bracketOnError
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, throwIO
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)
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import Control.Monad
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(
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void
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, when
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)
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import Data.ByteString
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(
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ByteString
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)
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import Data.Foldable
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(
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for_
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)
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import Data.Maybe
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(
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catMaybes
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)
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import Data.Word
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(
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Word8
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)
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import Foreign.C.Error
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(
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eEXIST
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, eNOTEMPTY
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, eXDEV
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)
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import Foreign.C.Types
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(
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CSize
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)
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import Foreign.Marshal.Alloc
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(
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allocaBytes
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)
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import Foreign.Ptr
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(
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Ptr
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)
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import GHC.IO.Exception
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(
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IOErrorType(..)
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)
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import HPath
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import HPath.Internal
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import HPath.IO.Errors
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import HPath.IO.Utils
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import Prelude hiding (readFile)
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import System.IO.Error
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(
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catchIOError
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, ioeGetErrorType
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)
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import System.Posix.ByteString
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(
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exclusive
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)
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import System.Posix.Directory.ByteString
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(
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createDirectory
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, removeDirectory
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)
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import System.Posix.Directory.Traversals
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(
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getDirectoryContents'
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)
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import System.Posix.Files.ByteString
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(
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createSymbolicLink
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, fileMode
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, getFdStatus
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, groupExecuteMode
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, groupReadMode
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, groupWriteMode
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, otherExecuteMode
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, otherReadMode
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, otherWriteMode
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, ownerModes
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, ownerReadMode
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, ownerWriteMode
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, readSymbolicLink
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, removeLink
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, rename
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, setFileMode
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, unionFileModes
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)
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import qualified System.Posix.Files.ByteString as PF
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import qualified "unix" System.Posix.IO.ByteString as SPI
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import qualified "unix-bytestring" System.Posix.IO.ByteString as SPB
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import qualified System.Posix.Directory.Traversals as SPDT
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import qualified System.Posix.Directory.Foreign as SPDF
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import qualified System.Posix.Process.ByteString as SPP
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import System.Posix.Types
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(
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FileMode
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, ProcessID
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, Fd
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)
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data FileType = Directory
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| RegularFile
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| SymbolicLink
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| BlockDevice
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| CharacterDevice
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| NamedPipe
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| Socket
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deriving (Eq, Show)
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--------------------
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--[ File Copying ]--
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--------------------
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-- |Copies a directory recursively to the given destination.
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-- Does not follow symbolic links.
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--
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-- Safety/reliability concerns:
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--
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-- * not atomic
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-- * examines filetypes explicitly
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-- * an explicit check `throwDestinationInSource` is carried out for the
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-- top directory for basic sanity, because otherwise we might end up
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-- with an infinite copy loop... however, this operation is not
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-- carried out recursively (because it's slow)
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--
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-- Throws:
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--
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-- - `NoSuchThing` if source directory does not exist
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-- - `PermissionDenied` if output directory is not writable
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-- - `PermissionDenied` if source directory can't be opened
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-- - `InvalidArgument` if source directory is wrong type (symlink)
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-- - `InvalidArgument` if source directory is wrong type (regular file)
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-- - `SameFile` if source and destination are the same file (`HPathIOException`)
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-- - `AlreadyExists` if destination already exists
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-- - `DestinationInSource` if destination is contained in source (`HPathIOException`)
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copyDirRecursive :: Path Abs -- ^ source dir
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-> Path Abs -- ^ full destination
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-> IO ()
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copyDirRecursive fromp destdirp
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= do
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-- for performance, sanity checks are only done for the top dir
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throwSameFile fromp destdirp
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throwDestinationInSource fromp destdirp
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go fromp destdirp
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where
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go :: Path Abs -> Path Abs -> IO ()
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go fromp' destdirp' = do
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-- order is important here, so we don't get empty directories
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-- on failure
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contents <- getDirsFiles fromp'
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fmode' <- PF.fileMode <$> PF.getSymbolicLinkStatus (fromAbs fromp')
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createDirectory (fromAbs destdirp') fmode'
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for_ contents $ \f -> do
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ftype <- getFileType f
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newdest <- (destdirp' </>) <$> basename f
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case ftype of
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SymbolicLink -> recreateSymlink f newdest
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Directory -> go f newdest
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RegularFile -> copyFile f newdest
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_ -> ioError $ userError $ "No idea what to do with the" ++
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"given filetype: " ++ show ftype
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import HPath
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import HPath.Internal
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import System.Posix.Directory.Traversals (realpath)
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-- |Like `copyDirRecursive` except it overwrites contents of directories
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-- if any.
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--
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-- Throws:
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--
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-- - `NoSuchThing` if source directory does not exist
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-- - `PermissionDenied` if output directory is not writable
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-- - `PermissionDenied` if source directory can't be opened
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-- - `InvalidArgument` if source directory is wrong type (symlink)
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-- - `InvalidArgument` if source directory is wrong type (regular file)
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-- - `SameFile` if source and destination are the same file (`HPathIOException`)
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-- - `DestinationInSource` if destination is contained in source (`HPathIOException`)
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copyDirRecursiveOverwrite :: Path Abs -- ^ source dir
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-> Path Abs -- ^ full destination
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-> IO ()
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copyDirRecursiveOverwrite fromp destdirp
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= do
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-- for performance, sanity checks are only done for the top dir
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throwSameFile fromp destdirp
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throwDestinationInSource fromp destdirp
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go fromp destdirp
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where
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go :: Path Abs -> Path Abs -> IO ()
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go fromp' destdirp' = do
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-- order is important here, so we don't get empty directories
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-- on failure
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contents <- getDirsFiles fromp'
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fmode' <- PF.fileMode <$> PF.getSymbolicLinkStatus (fromAbs fromp')
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catchIOError (createDirectory (fromAbs destdirp') fmode') $ \e ->
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case ioeGetErrorType e of
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AlreadyExists -> setFileMode (fromAbs destdirp') fmode'
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_ -> ioError e
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for_ contents $ \f -> do
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ftype <- getFileType f
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newdest <- (destdirp' </>) <$> basename f
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case ftype of
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SymbolicLink -> whenM (doesFileExist newdest) (deleteFile newdest)
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>> recreateSymlink f newdest
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Directory -> go f newdest
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RegularFile -> copyFileOverwrite f newdest
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_ -> ioError $ userError $ "No idea what to do with the" ++
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"given filetype: " ++ show ftype
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-- |Recreate a symlink.
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--
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-- Throws:
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--
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-- - `InvalidArgument` if symlink file is wrong type (file)
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-- - `InvalidArgument` if symlink file is wrong type (directory)
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-- - `PermissionDenied` if output directory cannot be written to
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-- - `PermissionDenied` if source directory cannot be opened
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-- - `AlreadyExists` if destination file already exists
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-- - `SameFile` if source and destination are the same file (`HPathIOException`)
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--
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-- Note: calls `symlink`
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recreateSymlink :: Path Abs -- ^ the old symlink file
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-> Path Abs -- ^ destination file
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-> IO ()
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recreateSymlink symsource newsym
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= do
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throwSameFile symsource newsym
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sympoint <- readSymbolicLink (fromAbs symsource)
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createSymbolicLink sympoint (fromAbs newsym)
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-- |Copies the given regular file to the given destination.
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-- Neither follows symbolic links, nor accepts them.
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-- For "copying" symbolic links, use `recreateSymlink` instead.
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--
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-- Throws:
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--
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-- - `NoSuchThing` if source file does not exist
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-- - `PermissionDenied` if output directory is not writable
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-- - `PermissionDenied` if source directory can't be opened
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-- - `InvalidArgument` if source file is wrong type (symlink)
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-- - `InvalidArgument` if source file is wrong type (directory)
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-- - `SameFile` if source and destination are the same file (`HPathIOException`)
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-- - `AlreadyExists` if destination already exists
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--
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-- Note: calls `sendfile`
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copyFile :: Path Abs -- ^ source file
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-> Path Abs -- ^ destination file
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-> IO ()
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copyFile from to = do
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throwSameFile from to
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_copyFile [SPDF.oNofollow]
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[SPDF.oNofollow, SPDF.oExcl]
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from to
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-- |Like `copyFile` except it overwrites the destination if it already
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-- exists.
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-- This also works if source and destination are the same file.
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--
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-- Safety/reliability concerns:
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--
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-- * not atomic
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-- * falls back to delete-copy method with explicit checks
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--
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-- Throws:
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--
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-- - `NoSuchThing` if source file does not exist
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-- - `PermissionDenied` if output directory is not writable
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-- - `PermissionDenied` if source directory can't be opened
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-- - `InvalidArgument` if source file is wrong type (symlink)
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-- - `InvalidArgument` if source file is wrong type (directory)
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-- - `SameFile` if source and destination are the same file (`HPathIOException`)
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--
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-- Note: calls `sendfile`
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copyFileOverwrite :: Path Abs -- ^ source file
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-> Path Abs -- ^ destination file
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-> IO ()
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copyFileOverwrite from to = do
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throwSameFile from to
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catchIOError (_copyFile [SPDF.oNofollow]
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[SPDF.oNofollow, SPDF.oTrunc]
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from to) $ \e ->
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case ioeGetErrorType e of
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-- if the destination file is not writable, we need to
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-- figure out if we can still copy by deleting it first
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PermissionDenied -> do
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exists <- doesFileExist to
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writable <- isWritable (dirname to)
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if exists && writable
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then deleteFile to >> copyFile from to
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else ioError e
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_ -> ioError e
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_copyFile :: [SPDF.Flags]
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-> [SPDF.Flags]
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-> Path Abs -- ^ source file
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-> Path Abs -- ^ destination file
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-> IO ()
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_copyFile sflags dflags from to
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=
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-- from sendfile(2) manpage:
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-- Applications may wish to fall back to read(2)/write(2) in the case
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-- where sendfile() fails with EINVAL or ENOSYS.
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withAbsPath to $ \to' -> withAbsPath from $ \from' ->
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void $ fallbackCopy from' to'
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where
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-- low-level copy operation utilizing read(2)/write(2)
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-- in case `sendFileCopy` fails/is unsupported
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fallbackCopy source dest =
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bracket (SPDT.openFd source SPI.ReadOnly sflags Nothing)
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SPI.closeFd
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$ \sfd -> do
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fileM <- System.Posix.Files.ByteString.fileMode
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<$> getFdStatus sfd
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bracketeer (SPDT.openFd dest SPI.WriteOnly
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dflags $ Just fileM)
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SPI.closeFd
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(\fd -> SPI.closeFd fd >> deleteFile to)
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$ \dfd -> allocaBytes (fromIntegral bufSize) $ \buf ->
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write' sfd dfd buf 0
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where
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bufSize :: CSize
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bufSize = 8192
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write' :: Fd -> Fd -> Ptr Word8 -> Int -> IO Int
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write' sfd dfd buf totalsize = do
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size <- SPB.fdReadBuf sfd buf bufSize
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if size == 0
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then return $ fromIntegral totalsize
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else do rsize <- SPB.fdWriteBuf dfd buf size
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when (rsize /= size) (throwIO . CopyFailed $ "wrong size!")
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write' sfd dfd buf (totalsize + fromIntegral size)
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-- |Copies anything. In case of a symlink,
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-- it is just recreated, even if it points to a directory.
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--
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-- Safety/reliability concerns:
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--
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-- * examines filetypes explicitly
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-- * calls `copyDirRecursive` for directories
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easyCopy :: Path Abs
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-> Path Abs
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-> IO ()
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easyCopy from to = do
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ftype <- getFileType from
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case ftype of
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SymbolicLink -> recreateSymlink from to
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RegularFile -> copyFile from to
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Directory -> copyDirRecursive from to
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_ -> ioError $ userError $ "No idea what to do with the" ++
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"given filetype: " ++ show ftype
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-- |Like `easyCopy` except it overwrites the destination if it already exists.
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-- For directories, this overwrites contents without pruning them, so the resulting
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-- directory may have more files than have been copied.
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easyCopyOverwrite :: Path Abs
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-> Path Abs
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-> IO ()
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easyCopyOverwrite from to = do
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ftype <- getFileType from
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case ftype of
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SymbolicLink -> whenM (doesFileExist to) (deleteFile to)
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>> recreateSymlink from to
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RegularFile -> copyFileOverwrite from to
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Directory -> copyDirRecursiveOverwrite from to
|
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_ -> ioError $ userError $ "No idea what to do with the" ++
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"given filetype: " ++ show ftype
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|
||||
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-- | May fail on `realpath`.
|
||||
|
||||
|
||||
|
||||
---------------------
|
||||
--[ File Deletion ]--
|
||||
---------------------
|
||||
|
||||
|
||||
-- |Deletes the given file, does not follow symlinks. Raises `eISDIR`
|
||||
-- if run on a directory. Does not follow symbolic links.
|
||||
--
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||||
-- Throws:
|
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--
|
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-- - `InappropriateType` for wrong file type (directory)
|
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-- - `NoSuchThing` if the file does not exist
|
||||
-- - `PermissionDenied` if the directory cannot be read
|
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deleteFile :: Path Abs -> IO ()
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deleteFile p = withAbsPath p removeLink
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|
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-- |Deletes the given directory, which must be empty, never symlinks.
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--
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||||
-- Throws:
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--
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||||
-- - `InappropriateType` for wrong file type (symlink to directory)
|
||||
-- - `InappropriateType` for wrong file type (regular file)
|
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-- - `NoSuchThing` if directory does not exist
|
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-- - `UnsatisfiedConstraints` if directory is not empty
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-- - `PermissionDenied` if we can't open or write to parent directory
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--
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-- Notes: calls `rmdir`
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deleteDir :: Path Abs -> IO ()
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deleteDir p = withAbsPath p removeDirectory
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|
||||
|
||||
-- |Deletes the given directory recursively. Does not follow symbolic
|
||||
-- links. Tries `deleteDir` first before attemtping a recursive
|
||||
-- deletion.
|
||||
--
|
||||
-- Safety/reliability concerns:
|
||||
--
|
||||
-- * not atomic
|
||||
-- * examines filetypes explicitly
|
||||
--
|
||||
-- Throws:
|
||||
--
|
||||
-- - `InappropriateType` for wrong file type (symlink to directory)
|
||||
-- - `InappropriateType` for wrong file type (regular file)
|
||||
-- - `NoSuchThing` if directory does not exist
|
||||
-- - `PermissionDenied` if we can't open or write to parent directory
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deleteDirRecursive :: Path Abs -> IO ()
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deleteDirRecursive p =
|
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catchErrno [eNOTEMPTY, eEXIST]
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||||
(deleteDir p)
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||||
$ do
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||||
files <- getDirsFiles p
|
||||
for_ files $ \file -> do
|
||||
ftype <- getFileType file
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||||
case ftype of
|
||||
SymbolicLink -> deleteFile file
|
||||
Directory -> deleteDirRecursive file
|
||||
RegularFile -> deleteFile file
|
||||
_ -> ioError $ userError $ "No idea what to do with the" ++
|
||||
"given filetype: " ++ show ftype
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||||
removeDirectory . toFilePath $ p
|
||||
|
||||
|
||||
-- |Deletes a file, directory or symlink, whatever it may be.
|
||||
-- In case of directory, performs recursive deletion. In case of
|
||||
-- a symlink, the symlink file is deleted.
|
||||
--
|
||||
-- Safety/reliability concerns:
|
||||
--
|
||||
-- * examines filetypes explicitly
|
||||
-- * calls `deleteDirRecursive` for directories
|
||||
easyDelete :: Path Abs -> IO ()
|
||||
easyDelete p = do
|
||||
ftype <- getFileType p
|
||||
case ftype of
|
||||
SymbolicLink -> deleteFile p
|
||||
Directory -> deleteDirRecursive p
|
||||
RegularFile -> deleteFile p
|
||||
_ -> ioError $ userError $ "No idea what to do with the" ++
|
||||
"given filetype: " ++ show ftype
|
||||
|
||||
|
||||
|
||||
|
||||
--------------------
|
||||
--[ File Opening ]--
|
||||
--------------------
|
||||
|
||||
|
||||
-- |Opens a file appropriately by invoking xdg-open. The file type
|
||||
-- is not checked.
|
||||
openFile :: Path Abs
|
||||
-> IO ProcessID
|
||||
openFile p =
|
||||
withAbsPath p $ \fp ->
|
||||
SPP.forkProcess $ SPP.executeFile "xdg-open" True [fp] Nothing
|
||||
|
||||
|
||||
-- |Executes a program with the given arguments.
|
||||
executeFile :: Path Abs -- ^ program
|
||||
-> [ByteString] -- ^ arguments
|
||||
-> IO ProcessID
|
||||
executeFile fp args
|
||||
= withAbsPath fp $ \fpb ->
|
||||
SPP.forkProcess
|
||||
$ SPP.executeFile fpb True args Nothing
|
||||
|
||||
|
||||
|
||||
|
||||
---------------------
|
||||
--[ File Creation ]--
|
||||
---------------------
|
||||
|
||||
|
||||
-- |Create an empty regular file at the given directory with the given filename.
|
||||
--
|
||||
-- Throws:
|
||||
--
|
||||
-- - `PermissionDenied` if output directory cannot be written to
|
||||
-- - `AlreadyExists` if destination file already exists
|
||||
createRegularFile :: Path Abs -> IO ()
|
||||
createRegularFile dest =
|
||||
bracket (SPI.openFd (fromAbs dest) SPI.WriteOnly (Just newFilePerms)
|
||||
(SPI.defaultFileFlags { exclusive = True }))
|
||||
SPI.closeFd
|
||||
(\_ -> return ())
|
||||
|
||||
|
||||
-- |Create an empty directory at the given directory with the given filename.
|
||||
--
|
||||
-- Throws:
|
||||
--
|
||||
-- - `PermissionDenied` if output directory cannot be written to
|
||||
-- - `AlreadyExists` if destination directory already exists
|
||||
createDir :: Path Abs -> IO ()
|
||||
createDir dest = createDirectory (fromAbs dest) newDirPerms
|
||||
|
||||
|
||||
|
||||
|
||||
----------------------------
|
||||
--[ File Renaming/Moving ]--
|
||||
----------------------------
|
||||
|
||||
|
||||
-- |Rename a given file with the provided filename. Destination and source
|
||||
-- must be on the same device, otherwise `eXDEV` will be raised.
|
||||
--
|
||||
-- Does not follow symbolic links, but renames the symbolic link file.
|
||||
--
|
||||
-- Safety/reliability concerns:
|
||||
--
|
||||
-- * has a separate set of exception handling, apart from the syscall
|
||||
--
|
||||
-- Throws:
|
||||
--
|
||||
-- - `NoSuchThing` if source file does not exist
|
||||
-- - `PermissionDenied` if output directory cannot be written to
|
||||
-- - `PermissionDenied` if source directory cannot be opened
|
||||
-- - `UnsupportedOperation` if source and destination are on different devices
|
||||
-- - `FileDoesExist` if destination file already exists
|
||||
-- - `DirDoesExist` if destination directory already exists
|
||||
-- - `SameFile` if destination and source are the same file (`HPathIOException`)
|
||||
--
|
||||
-- Note: calls `rename` (but does not allow to rename over existing files)
|
||||
renameFile :: Path Abs -> Path Abs -> IO ()
|
||||
renameFile fromf tof = do
|
||||
throwSameFile fromf tof
|
||||
throwFileDoesExist tof
|
||||
throwDirDoesExist tof
|
||||
rename (fromAbs fromf) (fromAbs tof)
|
||||
|
||||
|
||||
-- |Move a file. This also works across devices by copy-delete fallback.
|
||||
-- And also works on directories.
|
||||
--
|
||||
-- Does not follow symbolic links, but renames the symbolic link file.
|
||||
--
|
||||
-- Safety/reliability concerns:
|
||||
--
|
||||
-- * copy-delete fallback is inherently non-atomic
|
||||
--
|
||||
-- Throws:
|
||||
--
|
||||
-- - `NoSuchThing` if source file does not exist
|
||||
-- - `PermissionDenied` if output directory cannot be written to
|
||||
-- - `PermissionDenied` if source directory cannot be opened
|
||||
-- - `FileDoesExist` if destination file already exists
|
||||
-- - `DirDoesExist` if destination directory already exists
|
||||
-- - `SameFile` if destination and source are the same file (`HPathIOException`)
|
||||
--
|
||||
-- Note: calls `rename` (but does not allow to rename over existing files)
|
||||
moveFile :: Path Abs -- ^ file to move
|
||||
-> Path Abs -- ^ destination
|
||||
-> IO ()
|
||||
moveFile from to = do
|
||||
throwSameFile from to
|
||||
catchErrno [eXDEV] (renameFile from to) $ do
|
||||
easyCopy from to
|
||||
easyDelete from
|
||||
|
||||
|
||||
-- |Like `moveFile`, but overwrites the destination if it exists.
|
||||
--
|
||||
-- Does not follow symbolic links, but renames the symbolic link file.
|
||||
--
|
||||
-- Safety/reliability concerns:
|
||||
--
|
||||
-- * copy-delete fallback is inherently non-atomic
|
||||
-- * checks for file types and destination file existence explicitly
|
||||
--
|
||||
-- Throws:
|
||||
--
|
||||
-- - `NoSuchThing` if source file does not exist
|
||||
-- - `PermissionDenied` if output directory cannot be written to
|
||||
-- - `PermissionDenied` if source directory cannot be opened
|
||||
-- - `SameFile` if destination and source are the same file (`HPathIOException`)
|
||||
--
|
||||
-- Note: calls `rename` (but does not allow to rename over existing files)
|
||||
moveFileOverwrite :: Path Abs -- ^ file to move
|
||||
-> Path Abs -- ^ destination
|
||||
-> IO ()
|
||||
moveFileOverwrite from to = do
|
||||
throwSameFile from to
|
||||
ft <- getFileType from
|
||||
writable <- isWritable $ dirname to
|
||||
case ft of
|
||||
RegularFile -> do
|
||||
exists <- doesFileExist to
|
||||
when (exists && writable) (deleteFile to)
|
||||
SymbolicLink -> do
|
||||
exists <- doesFileExist to
|
||||
when (exists && writable) (deleteFile to)
|
||||
Directory -> do
|
||||
exists <- doesDirectoryExist to
|
||||
when (exists && writable) (deleteDir to)
|
||||
_ -> ioError $ userError $ "Don't know how to handle filetype " ++
|
||||
show ft
|
||||
moveFile from to
|
||||
|
||||
|
||||
|
||||
|
||||
-----------------------
|
||||
--[ File Permissions]--
|
||||
-----------------------
|
||||
|
||||
|
||||
-- |Default permissions for a new file.
|
||||
newFilePerms :: FileMode
|
||||
newFilePerms
|
||||
= ownerWriteMode
|
||||
`unionFileModes` ownerReadMode
|
||||
`unionFileModes` groupWriteMode
|
||||
`unionFileModes` groupReadMode
|
||||
`unionFileModes` otherWriteMode
|
||||
`unionFileModes` otherReadMode
|
||||
|
||||
|
||||
-- |Default permissions for a new directory.
|
||||
newDirPerms :: FileMode
|
||||
newDirPerms
|
||||
= ownerModes
|
||||
`unionFileModes` groupExecuteMode
|
||||
`unionFileModes` groupReadMode
|
||||
`unionFileModes` otherExecuteMode
|
||||
`unionFileModes` otherReadMode
|
||||
|
||||
|
||||
|
||||
-------------------------
|
||||
--[ Directory reading ]--
|
||||
-------------------------
|
||||
|
||||
|
||||
-- |Gets all filenames of the given directory. This excludes "." and "..".
|
||||
-- This version does not follow symbolic links.
|
||||
--
|
||||
-- Throws:
|
||||
--
|
||||
-- - `NoSuchThing` if directory does not exist
|
||||
-- - `InappropriateType` if file type is wrong (file)
|
||||
-- - `InappropriateType` if file type is wrong (symlink to file)
|
||||
-- - `InappropriateType` if file type is wrong (symlink to dir)
|
||||
-- - `PermissionDenied` if directory cannot be opened
|
||||
getDirsFiles :: Path Abs -- ^ dir to read
|
||||
-> IO [Path Abs]
|
||||
getDirsFiles p =
|
||||
withAbsPath p $ \fp ->
|
||||
bracketOnError (SPDT.openFd fp SPI.ReadOnly [SPDF.oNofollow] Nothing)
|
||||
SPI.closeFd
|
||||
$ \fd ->
|
||||
return
|
||||
. catMaybes
|
||||
. fmap (\x -> (</>) p <$> (parseMaybe . snd $ x))
|
||||
=<< getDirectoryContents' fd
|
||||
where
|
||||
parseMaybe :: ByteString -> Maybe (Path Fn)
|
||||
parseMaybe = parseFn
|
||||
|
||||
|
||||
|
||||
|
||||
---------------------------
|
||||
--[ FileType operations ]--
|
||||
---------------------------
|
||||
|
||||
|
||||
-- |Get the file type of the file located at the given path. Does
|
||||
-- not follow symbolic links.
|
||||
--
|
||||
-- Throws:
|
||||
--
|
||||
-- - `NoSuchThing` if the file does not exist
|
||||
-- - `PermissionDenied` if any part of the path is not accessible
|
||||
getFileType :: Path Abs -> IO FileType
|
||||
getFileType p = do
|
||||
fs <- PF.getSymbolicLinkStatus (fromAbs p)
|
||||
decide fs
|
||||
where
|
||||
decide fs
|
||||
| PF.isDirectory fs = return Directory
|
||||
| PF.isRegularFile fs = return RegularFile
|
||||
| PF.isSymbolicLink fs = return SymbolicLink
|
||||
| PF.isBlockDevice fs = return BlockDevice
|
||||
| PF.isCharacterDevice fs = return CharacterDevice
|
||||
| PF.isNamedPipe fs = return NamedPipe
|
||||
| PF.isSocket fs = return Socket
|
||||
| otherwise = ioError $ userError "No filetype?!"
|
||||
|
||||
|
||||
|
||||
--------------
|
||||
--[ Others ]--
|
||||
--------------
|
||||
|
||||
|
||||
|
||||
-- |Applies `realpath` on the given absolute path.
|
||||
--
|
||||
-- Throws:
|
||||
--
|
||||
-- - `NoSuchThing` if the file at the given path does not exist
|
||||
-- - `NoSuchThing` if the symlink is broken
|
||||
canonicalizePath :: Path Abs -> IO (Path Abs)
|
||||
canonicalizePath (MkPath l) = do
|
||||
nl <- realpath l
|
||||
nl <- SPDT.realpath l
|
||||
return $ MkPath nl
|
||||
|
||||
331
src/HPath/IO/Errors.hs
Normal file
331
src/HPath/IO/Errors.hs
Normal file
@@ -0,0 +1,331 @@
|
||||
-- |
|
||||
-- Module : HPath.IO.Errors
|
||||
-- Copyright : © 2016 Julian Ospald
|
||||
-- License : GPL-2
|
||||
--
|
||||
-- Maintainer : Julian Ospald <hasufell@posteo.de>
|
||||
-- Stability : experimental
|
||||
-- Portability : portable
|
||||
--
|
||||
-- Provides error handling.
|
||||
|
||||
{-# LANGUAGE DeriveDataTypeable #-}
|
||||
{-# LANGUAGE ScopedTypeVariables #-}
|
||||
{-# OPTIONS_HADDOCK ignore-exports #-}
|
||||
|
||||
module HPath.IO.Errors where
|
||||
|
||||
|
||||
import Control.Exception
|
||||
import Control.Monad
|
||||
(
|
||||
forM
|
||||
, when
|
||||
)
|
||||
import Data.ByteString
|
||||
(
|
||||
ByteString
|
||||
)
|
||||
import Data.Data
|
||||
(
|
||||
Data(..)
|
||||
)
|
||||
import Data.Typeable
|
||||
import Foreign.C.Error
|
||||
(
|
||||
getErrno
|
||||
, Errno
|
||||
)
|
||||
import GHC.IO.Exception
|
||||
(
|
||||
IOErrorType
|
||||
)
|
||||
import HPath
|
||||
import HPath.IO.Utils
|
||||
{- import HPath.IO -}
|
||||
{- ( -}
|
||||
{- canonicalizePath -}
|
||||
{- ) -}
|
||||
import System.IO.Error
|
||||
(
|
||||
catchIOError
|
||||
, ioeGetErrorType
|
||||
)
|
||||
|
||||
import qualified System.Posix.Directory.ByteString as PFD
|
||||
import System.Posix.Files.ByteString
|
||||
(
|
||||
fileAccess
|
||||
, getFileStatus
|
||||
)
|
||||
import qualified System.Posix.Files.ByteString as PF
|
||||
|
||||
|
||||
data HPathIOException = FileDoesNotExist ByteString
|
||||
| DirDoesNotExist ByteString
|
||||
| PathNotAbsolute ByteString
|
||||
| FileNotExecutable ByteString
|
||||
| SameFile ByteString ByteString
|
||||
| NotAFile ByteString
|
||||
| NotADir ByteString
|
||||
| DestinationInSource ByteString ByteString
|
||||
| FileDoesExist ByteString
|
||||
| DirDoesExist ByteString
|
||||
| IsSymlink ByteString
|
||||
| InvalidOperation String
|
||||
| InvalidFileName
|
||||
| Can'tOpenDirectory ByteString
|
||||
| CopyFailed String
|
||||
| MoveFailed String
|
||||
deriving (Typeable, Eq, Data)
|
||||
|
||||
|
||||
instance Show HPathIOException where
|
||||
show (FileDoesNotExist fp) = "File does not exist:" ++ fpToString fp
|
||||
show (DirDoesNotExist fp) = "Directory does not exist: "
|
||||
++ fpToString fp
|
||||
show (PathNotAbsolute fp) = "Path not absolute: " ++ fpToString fp
|
||||
show (FileNotExecutable fp) = "File not executable: "
|
||||
++ fpToString fp
|
||||
show (SameFile fp1 fp2) = fpToString fp1
|
||||
++ " and " ++ fpToString fp2
|
||||
++ " are the same file!"
|
||||
show (NotAFile fp) = "Not a file: " ++ fpToString fp
|
||||
show (NotADir fp) = "Not a directory: " ++ fpToString fp
|
||||
show (DestinationInSource fp1 fp2) = fpToString fp1
|
||||
++ " is contained in "
|
||||
++ fpToString fp2
|
||||
show (FileDoesExist fp) = "File does exist: " ++ fpToString fp
|
||||
show (DirDoesExist fp) = "Directory does exist: " ++ fpToString fp
|
||||
show (IsSymlink fp) = "Is a symlink: " ++ fpToString fp
|
||||
show (InvalidOperation str) = "Invalid operation: " ++ str
|
||||
show InvalidFileName = "Invalid file name!"
|
||||
show (Can'tOpenDirectory fp) = "Can't open directory: "
|
||||
++ fpToString fp
|
||||
show (CopyFailed str) = "Copying failed: " ++ str
|
||||
show (MoveFailed str) = "Moving failed: " ++ str
|
||||
|
||||
|
||||
|
||||
instance Exception HPathIOException
|
||||
|
||||
|
||||
|
||||
isDestinationInSource :: HPathIOException -> Bool
|
||||
isDestinationInSource (DestinationInSource _ _) = True
|
||||
isDestinationInSource _ = False
|
||||
|
||||
|
||||
isSameFile :: HPathIOException -> Bool
|
||||
isSameFile (SameFile _ _) = True
|
||||
isSameFile _ = False
|
||||
|
||||
|
||||
isFileDoesExist :: HPathIOException -> Bool
|
||||
isFileDoesExist (FileDoesExist _) = True
|
||||
isFileDoesExist _ = False
|
||||
|
||||
|
||||
isDirDoesExist :: HPathIOException -> Bool
|
||||
isDirDoesExist (DirDoesExist _) = True
|
||||
isDirDoesExist _ = False
|
||||
|
||||
|
||||
|
||||
----------------------------
|
||||
--[ Path based functions ]--
|
||||
----------------------------
|
||||
|
||||
|
||||
throwFileDoesExist :: Path Abs -> IO ()
|
||||
throwFileDoesExist fp =
|
||||
whenM (doesFileExist fp) (throwIO . FileDoesExist
|
||||
. fromAbs $ fp)
|
||||
|
||||
|
||||
throwDirDoesExist :: Path Abs -> IO ()
|
||||
throwDirDoesExist fp =
|
||||
whenM (doesDirectoryExist fp) (throwIO . DirDoesExist
|
||||
. fromAbs $ fp)
|
||||
|
||||
|
||||
throwFileDoesNotExist :: Path Abs -> IO ()
|
||||
throwFileDoesNotExist fp =
|
||||
unlessM (doesFileExist fp) (throwIO . FileDoesNotExist
|
||||
. fromAbs $ fp)
|
||||
|
||||
|
||||
throwDirDoesNotExist :: Path Abs -> IO ()
|
||||
throwDirDoesNotExist fp =
|
||||
unlessM (doesDirectoryExist fp) (throwIO . DirDoesNotExist
|
||||
. fromAbs $ fp)
|
||||
|
||||
|
||||
-- |Uses `isSameFile` and throws `SameFile` if it returns True.
|
||||
throwSameFile :: Path Abs
|
||||
-> Path Abs
|
||||
-> IO ()
|
||||
throwSameFile fp1 fp2 =
|
||||
whenM (sameFile fp1 fp2)
|
||||
(throwIO $ SameFile (fromAbs fp1) (fromAbs fp2))
|
||||
|
||||
|
||||
-- |Check if the files are the same by examining device and file id.
|
||||
-- This follows symbolic links.
|
||||
sameFile :: Path Abs -> Path Abs -> IO Bool
|
||||
sameFile fp1 fp2 =
|
||||
withAbsPath fp1 $ \fp1' -> withAbsPath fp2 $ \fp2' ->
|
||||
handleIOError (\_ -> return False) $ do
|
||||
fs1 <- getFileStatus fp1'
|
||||
fs2 <- getFileStatus fp2'
|
||||
|
||||
if ((PF.deviceID fs1, PF.fileID fs1) ==
|
||||
(PF.deviceID fs2, PF.fileID fs2))
|
||||
then return True
|
||||
else return False
|
||||
|
||||
|
||||
-- |Checks whether the destination directory is contained
|
||||
-- within the source directory by comparing the device+file ID of the
|
||||
-- source directory with all device+file IDs of the parent directories
|
||||
-- of the destination.
|
||||
throwDestinationInSource :: Path Abs -- ^ source dir
|
||||
-> Path Abs -- ^ full destination, `dirname dest`
|
||||
-- must exist
|
||||
-> IO ()
|
||||
throwDestinationInSource source dest = do
|
||||
dest' <- (\x -> maybe x (\y -> x </> y) $ basename dest)
|
||||
{- <$> (canonicalizePath $ P.dirname dest) -}
|
||||
<$> (return $ dirname dest)
|
||||
dids <- forM (getAllParents dest') $ \p -> do
|
||||
fs <- PF.getSymbolicLinkStatus (fromAbs p)
|
||||
return (PF.deviceID fs, PF.fileID fs)
|
||||
sid <- fmap (\x -> (PF.deviceID x, PF.fileID x))
|
||||
$ PF.getFileStatus (fromAbs source)
|
||||
when (elem sid dids)
|
||||
(throwIO $ DestinationInSource (fromAbs dest)
|
||||
(fromAbs source))
|
||||
|
||||
|
||||
-- |Checks if the given file exists and is not a directory.
|
||||
-- Does not follow symlinks.
|
||||
doesFileExist :: Path Abs -> IO Bool
|
||||
doesFileExist fp =
|
||||
handleIOError (\_ -> return False) $ do
|
||||
fs <- PF.getSymbolicLinkStatus (fromAbs fp)
|
||||
return $ not . PF.isDirectory $ fs
|
||||
|
||||
|
||||
-- |Checks if the given file exists and is a directory.
|
||||
-- Does not follow symlinks.
|
||||
doesDirectoryExist :: Path Abs -> IO Bool
|
||||
doesDirectoryExist fp =
|
||||
handleIOError (\_ -> return False) $ do
|
||||
fs <- PF.getSymbolicLinkStatus (fromAbs fp)
|
||||
return $ PF.isDirectory fs
|
||||
|
||||
|
||||
-- |Checks whether a file or folder is writable.
|
||||
isWritable :: Path Abs -> IO Bool
|
||||
isWritable fp =
|
||||
handleIOError (\_ -> return False) $
|
||||
fileAccess (fromAbs fp) False True False
|
||||
|
||||
|
||||
-- |Checks whether the directory at the given path exists and can be
|
||||
-- opened. This invokes `openDirStream` which follows symlinks.
|
||||
canOpenDirectory :: Path Abs -> IO Bool
|
||||
canOpenDirectory fp =
|
||||
handleIOError (\_ -> return False) $ do
|
||||
bracket (PFD.openDirStream . fromAbs $ fp)
|
||||
PFD.closeDirStream
|
||||
(\_ -> return ())
|
||||
return True
|
||||
|
||||
|
||||
-- |Throws a `Can'tOpenDirectory` FmIOException if the directory at the given
|
||||
-- path cannot be opened.
|
||||
throwCantOpenDirectory :: Path Abs -> IO ()
|
||||
throwCantOpenDirectory fp =
|
||||
unlessM (canOpenDirectory fp)
|
||||
(throwIO . Can'tOpenDirectory . fromAbs $ fp)
|
||||
|
||||
|
||||
|
||||
--------------------------------
|
||||
--[ Error handling functions ]--
|
||||
--------------------------------
|
||||
|
||||
|
||||
-- |Carries out an action, then checks if there is an IOException and
|
||||
-- a specific errno. If so, then it carries out another action, otherwise
|
||||
-- it rethrows the error.
|
||||
catchErrno :: [Errno] -- ^ errno to catch
|
||||
-> IO a -- ^ action to try, which can raise an IOException
|
||||
-> IO a -- ^ action to carry out in case of an IOException and
|
||||
-- if errno matches
|
||||
-> IO a
|
||||
catchErrno en a1 a2 =
|
||||
catchIOError a1 $ \e -> do
|
||||
errno <- getErrno
|
||||
if errno `elem` en
|
||||
then a2
|
||||
else ioError e
|
||||
|
||||
|
||||
-- |Execute the given action and retrow IO exceptions as a new Exception
|
||||
-- that have the given errno. If errno does not match the exception is rethrown
|
||||
-- as is.
|
||||
rethrowErrnoAs :: Exception e
|
||||
=> [Errno] -- ^ errno to catch
|
||||
-> e -- ^ rethrow as if errno matches
|
||||
-> IO a -- ^ action to try
|
||||
-> IO a
|
||||
rethrowErrnoAs en fmex action = catchErrno en action (throwIO fmex)
|
||||
|
||||
|
||||
|
||||
-- |Like `catchIOError`, with arguments swapped.
|
||||
handleIOError :: (IOError -> IO a) -> IO a -> IO a
|
||||
handleIOError = flip catchIOError
|
||||
|
||||
|
||||
-- |Like `bracket`, but allows to have different clean-up
|
||||
-- actions depending on whether the in-between computation
|
||||
-- has raised an exception or not.
|
||||
bracketeer :: IO a -- ^ computation to run first
|
||||
-> (a -> IO b) -- ^ computation to run last, when
|
||||
-- no exception was raised
|
||||
-> (a -> IO b) -- ^ computation to run last,
|
||||
-- when an exception was raised
|
||||
-> (a -> IO c) -- ^ computation to run in-between
|
||||
-> IO c
|
||||
bracketeer before after afterEx thing =
|
||||
mask $ \restore -> do
|
||||
a <- before
|
||||
r <- restore (thing a) `onException` afterEx a
|
||||
_ <- after a
|
||||
return r
|
||||
|
||||
|
||||
reactOnError :: IO a
|
||||
-> [(IOErrorType, IO a)] -- ^ reaction on IO errors
|
||||
-> [(HPathIOException, IO a)] -- ^ reaction on FmIOException
|
||||
-> IO a
|
||||
reactOnError a ios fmios =
|
||||
a `catches` [iohandler, fmiohandler]
|
||||
where
|
||||
iohandler = Handler $
|
||||
\(ex :: IOException) ->
|
||||
foldr (\(t, a') y -> if ioeGetErrorType ex == t
|
||||
then a'
|
||||
else y)
|
||||
(throwIO ex)
|
||||
ios
|
||||
fmiohandler = Handler $
|
||||
\(ex :: HPathIOException) ->
|
||||
foldr (\(t, a') y -> if toConstr ex == toConstr t
|
||||
then a'
|
||||
else y)
|
||||
(throwIO ex)
|
||||
fmios
|
||||
34
src/HPath/IO/Utils.hs
Normal file
34
src/HPath/IO/Utils.hs
Normal file
@@ -0,0 +1,34 @@
|
||||
-- |
|
||||
-- Module : HPath.IO.Utils
|
||||
-- Copyright : © 2016 Julian Ospald
|
||||
-- License : GPL-2
|
||||
--
|
||||
-- Maintainer : Julian Ospald <hasufell@posteo.de>
|
||||
-- Stability : experimental
|
||||
-- Portability : portable
|
||||
--
|
||||
-- Random and general IO/monad utilities.
|
||||
|
||||
{-# OPTIONS_HADDOCK ignore-exports #-}
|
||||
|
||||
|
||||
module HPath.IO.Utils where
|
||||
|
||||
|
||||
import Control.Monad
|
||||
(
|
||||
when
|
||||
, unless
|
||||
)
|
||||
|
||||
|
||||
-- |If the value of the first argument is True, then execute the action
|
||||
-- provided in the second argument, otherwise do nothing.
|
||||
whenM :: Monad m => m Bool -> m () -> m ()
|
||||
whenM mb a = mb >>= (`when` a)
|
||||
|
||||
|
||||
-- |If the value of the first argument is False, then execute the action
|
||||
-- provided in the second argument, otherwise do nothing.
|
||||
unlessM :: Monad m => m Bool -> m () -> m ()
|
||||
unlessM mb a = mb >>= (`unless` a)
|
||||
Reference in New Issue
Block a user