61 lines
1.6 KiB
Haskell
61 lines
1.6 KiB
Haskell
{- file copying
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-
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- Copyright 2010-2014 Joey Hess <id@joeyh.name>
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-
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- License: BSD-2-clause
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-}
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{-# LANGUAGE CPP #-}
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module Utility.CopyFile (
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copyFileExternal,
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createLinkOrCopy,
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CopyMetaData(..)
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) where
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import Common
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import qualified Build.SysConfig as SysConfig
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data CopyMetaData
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-- Copy timestamps when possible, but no other metadata, and
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-- when copying a symlink, makes a copy of its content.
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= CopyTimeStamps
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-- Copy all metadata when possible.
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| CopyAllMetaData
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deriving (Eq)
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{- The cp command is used, because I hate reinventing the wheel,
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- and because this allows easy access to features like cp --reflink. -}
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copyFileExternal :: CopyMetaData -> FilePath -> FilePath -> IO Bool
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copyFileExternal meta src dest = do
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whenM (doesFileExist dest) $
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removeFile dest
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boolSystem "cp" $ params ++ [File src, File dest]
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where
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#ifndef __ANDROID__
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params = map snd $ filter fst
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[ (SysConfig.cp_reflink_auto, Param "--reflink=auto")
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, (allmeta && SysConfig.cp_a, Param "-a")
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, (allmeta && SysConfig.cp_p && not SysConfig.cp_a
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, Param "-p")
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, (not allmeta && SysConfig.cp_preserve_timestamps
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, Param "--preserve=timestamps")
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]
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#else
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params = if allmeta then [] else []
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#endif
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allmeta = meta == CopyAllMetaData
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{- Create a hard link if the filesystem allows it, and fall back to copying
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- the file. -}
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createLinkOrCopy :: FilePath -> FilePath -> IO Bool
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#ifndef mingw32_HOST_OS
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createLinkOrCopy src dest = go `catchIO` const fallback
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where
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go = do
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createLink src dest
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return True
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fallback = copyFileExternal CopyAllMetaData src dest
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#else
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createLinkOrCopy = copyFileExternal CopyAllMetaData
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#endif
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