git-annex/Utility/CopyFile.hs
Joey Hess 308cd1383c
fold Build/SysConfig.hs into BuildInfo via include
This avoids warnings from stack about the module not being listed in the
cabal file. So, the generated file is also renamed to Build/SysConfig.

Note that the setup program seems to be cached despite these changes; I
had to cabal clean to get cabal to update it so that Build/SysConfig was
written.

This commit was sponsored by Jochen Bartl on Patreon.
2017-12-14 12:46:57 -04:00

57 lines
1.5 KiB
Haskell

{- file copying
-
- Copyright 2010-2014 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE CPP #-}
module Utility.CopyFile (
copyFileExternal,
createLinkOrCopy,
CopyMetaData(..)
) where
import Common
import qualified BuildInfo
data CopyMetaData
-- Copy timestamps when possible, but no other metadata, and
-- when copying a symlink, makes a copy of its content.
= CopyTimeStamps
-- Copy all metadata when possible.
| 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
[ (BuildInfo.cp_reflink_auto, Param "--reflink=auto")
, (allmeta && BuildInfo.cp_a, Param "-a")
, (allmeta && BuildInfo.cp_p && not BuildInfo.cp_a
, Param "-p")
, (not allmeta && BuildInfo.cp_preserve_timestamps
, Param "--preserve=timestamps")
]
#else
params = if allmeta then [] else []
#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
createLinkOrCopy src dest = go `catchIO` const fallback
where
go = do
createLink src dest
return True
fallback = copyFileExternal CopyAllMetaData src dest