git-annex/Utility/CopyFile.hs
Joey Hess 7b50b3c057 fix some mixed space+tab indentation
This fixes all instances of " \t" in the code base. Most common case
seems to be after a "where" line; probably vim copied the two space layout
of that line.

Done as a background task while listening to episode 2 of the Type Theory
podcast.
2014-10-09 15:09:11 -04:00

56 lines
1.4 KiB
Haskell

{- file copying
-
- Copyright 2010-2014 Joey Hess <joey@kitenet.net>
-
- License: BSD-2-clause
-}
{-# LANGUAGE CPP #-}
module Utility.CopyFile (
copyFileExternal,
createLinkOrCopy,
CopyMetaData(..)
) where
import Common
import qualified Build.SysConfig as SysConfig
data CopyMetaData = CopyTimeStamps | CopyAllMetaData
deriving (Eq)
{- The cp command is used, because I hate reinventing the wheel,
- and because this allows easy access to features like cp --reflink. -}
copyFileExternal :: CopyMetaData -> FilePath -> FilePath -> IO Bool
copyFileExternal meta src dest = do
whenM (doesFileExist dest) $
removeFile dest
boolSystem "cp" $ params ++ [File src, File dest]
where
#ifndef __ANDROID__
params = map snd $ filter fst
[ (SysConfig.cp_reflink_auto, Param "--reflink=auto")
, (allmeta && SysConfig.cp_a, Param "-a")
, (allmeta && SysConfig.cp_p && not SysConfig.cp_a
, Param "-p")
, (not allmeta && SysConfig.cp_preserve_timestamps
, Param "--preserve=timestamps")
]
#else
params = []
#endif
allmeta = meta == CopyAllMetaData
{- Create a hard link if the filesystem allows it, and fall back to copying
- the file. -}
createLinkOrCopy :: FilePath -> FilePath -> IO Bool
#ifndef mingw32_HOST_OS
createLinkOrCopy src dest = go `catchIO` const fallback
where
go = do
createLink src dest
return True
fallback = copyFileExternal CopyAllMetaData src dest
#else
createLinkOrCopy = copyFileExternal CopyAllMetaData
#endif