git-annex/Utility/Directory.hs
Joey Hess 67fd06af76 add git annex view command
(And a vpop command, which is still a bit buggy.)

Still need to do vadd and vrm, though this also adds their documentation.

Currently not very happy with the view log data serialization. I had to
lose the TDFA regexps temporarily, so I can have Read/Show instances of
View. I expect the view log format will change in some incompatable way
later, probably adding last known refs for the parent branch to View
or something like that.

Anyway, it basically works, although it's a bit slow looking up the
metadata. The actual git branch construction is about as fast as it can be
using the current git plumbing.

This commit was sponsored by Peter Hogg.
2014-02-18 18:22:20 -04:00

135 lines
4 KiB
Haskell

{- directory manipulation
-
- Copyright 2011-2014 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Utility.Directory where
import System.IO.Error
import System.Directory
import Control.Exception (throw)
import Control.Monad
import Control.Monad.IfElse
import System.FilePath
import Control.Applicative
import System.IO.Unsafe (unsafeInterleaveIO)
import Utility.PosixFiles
import Utility.SafeCommand
import Utility.Tmp
import Utility.Exception
import Utility.Monad
import Utility.Applicative
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 topdir = dirContentsRecursiveSkipping (const False) True topdir
{- 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 $ getSymbolicLinkStatus 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 c
=<< filterM (isDirectory <$$> getSymbolicLinkStatus)
=<< catchDefaultIO [] (dirContents dir)
go (subdirs++[dir]) dirs
{- Moves one filename to another.
- First tries a rename, but falls back to moving across devices if needed. -}
moveFile :: FilePath -> FilePath -> IO ()
moveFile src dest = tryIO (rename src dest) >>= onrename
where
onrename (Right _) = noop
onrename (Left e)
| isPermissionError e = rethrow
| isDoesNotExistError e = rethrow
| otherwise = do
-- copyFile is likely not as optimised as
-- the mv command, so we'll use the latter.
-- But, mv will move into a directory if
-- dest is one, which is not desired.
whenM (isdir dest) rethrow
viaTmp mv dest undefined
where
rethrow = throw e
mv tmp _ = do
ok <- boolSystem "mv" [Param "-f", Param src, Param tmp]
unless ok $ do
-- delete any partial
_ <- tryIO $ removeFile tmp
rethrow
isdir f = do
r <- tryIO $ getFileStatus f
case r of
(Left _) -> return False
(Right s) -> return $ isDirectory s
{- Removes a file, which may or may not exist, and does not have to
- be a regular file.
-
- Note that an exception is thrown if the file exists but
- cannot be removed. -}
nukeFile :: FilePath -> IO ()
nukeFile file = void $ tryWhenExists go
where
#ifndef mingw32_HOST_OS
go = removeLink file
#else
go = removeFile file
#endif