git-annex/Utility/Directory.hs
Joey Hess 54ad1b4cfb
Windows: Support long filenames in more (possibly all) of the code
Works around this bug in unix-compat:
https://github.com/jacobstanley/unix-compat/issues/56
getFileStatus and other FilePath using functions in unix-compat do not do
UNC conversion on Windows.

Made Utility.RawFilePath use convertToWindowsNativeNamespace to do the
necessary conversion on windows to support long filenames.

Audited all imports of System.PosixCompat.Files to make sure that no
functions that operate on FilePath were imported from it. Instead, use
the equvilants from Utility.RawFilePath. In particular the
re-export of that module in Common had to be removed, which led to lots
of other changes throughout the code.

The changes to Build.Configure, Build.DesktopFile, and Build.TestConfig
make Utility.Directory not be needed to build setup. And so let it use
Utility.RawFilePath, which depends on unix, which cannot be in
setup-depends.

Sponsored-by: Dartmouth College's Datalad project
2023-03-01 15:55:58 -04:00

101 lines
3.2 KiB
Haskell

{- directory traversal and manipulation
-
- Copyright 2011-2020 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE LambdaCase #-}
{-# OPTIONS_GHC -fno-warn-tabs #-}
module Utility.Directory (
module Utility.Directory,
module Utility.SystemDirectory
) where
import Control.Monad
import System.FilePath
import System.PosixCompat.Files (isDirectory, isSymbolicLink)
import Control.Applicative
import System.IO.Unsafe (unsafeInterleaveIO)
import Data.Maybe
import Prelude
import Utility.SystemDirectory
import Utility.Exception
import Utility.Monad
import Utility.FileSystemEncoding
import qualified Utility.RawFilePath as R
dirCruft :: FilePath -> Bool
dirCruft "." = True
dirCruft ".." = True
dirCruft _ = False
{- Lists the contents of a directory.
- Unlike getDirectoryContents, paths are not relative to the directory. -}
dirContents :: FilePath -> IO [FilePath]
dirContents d = map (d </>) . filter (not . dirCruft) <$> getDirectoryContents d
{- Gets files in a directory, and then its subdirectories, recursively,
- and lazily.
-
- Does not follow symlinks to other subdirectories.
-
- When the directory does not exist, no exception is thrown,
- instead, [] is returned. -}
dirContentsRecursive :: FilePath -> IO [FilePath]
dirContentsRecursive = dirContentsRecursiveSkipping (const False) True
{- Skips directories whose basenames match the skipdir. -}
dirContentsRecursiveSkipping :: (FilePath -> Bool) -> Bool -> FilePath -> IO [FilePath]
dirContentsRecursiveSkipping skipdir followsubdirsymlinks topdir = go [topdir]
where
go [] = return []
go (dir:dirs)
| skipdir (takeFileName dir) = go dirs
| otherwise = unsafeInterleaveIO $ do
(files, dirs') <- collect [] []
=<< catchDefaultIO [] (dirContents dir)
files' <- go (dirs' ++ dirs)
return (files ++ files')
collect files dirs' [] = return (reverse files, reverse dirs')
collect files dirs' (entry:entries)
| dirCruft entry = collect files dirs' entries
| otherwise = do
let skip = collect (entry:files) dirs' entries
let recurse = collect files (entry:dirs') entries
ms <- catchMaybeIO $ R.getSymbolicLinkStatus (toRawFilePath entry)
case ms of
(Just s)
| isDirectory s -> recurse
| isSymbolicLink s && followsubdirsymlinks ->
ifM (doesDirectoryExist entry)
( recurse
, skip
)
_ -> skip
{- Gets the directory tree from a point, recursively and lazily,
- with leaf directories **first**, skipping any whose basenames
- match the skipdir. Does not follow symlinks. -}
dirTreeRecursiveSkipping :: (FilePath -> Bool) -> FilePath -> IO [FilePath]
dirTreeRecursiveSkipping skipdir topdir = go [] [topdir]
where
go c [] = return c
go c (dir:dirs)
| skipdir (takeFileName dir) = go c dirs
| otherwise = unsafeInterleaveIO $ do
subdirs <- go []
=<< filterM isdir
=<< catchDefaultIO [] (dirContents dir)
go (subdirs++dir:c) dirs
isdir p = isDirectory <$> R.getSymbolicLinkStatus (toRawFilePath p)
{- Use with an action that removes something, which may or may not exist.
-
- If an exception is thrown due to it not existing, it is ignored.
-}
removeWhenExistsWith :: (a -> IO ()) -> a -> IO ()
removeWhenExistsWith f a = void $ tryWhenExists $ f a