Merge from git-annex.

1 files changed, 74 insertions, 0 deletions

diff --git a/Utility/MoveFile.hs b/Utility/MoveFile.hs
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+{- moving files
+ -
+ - Copyright 2011-2020 Joey Hess <id@joeyh.name>
+ -
+ - License: BSD-2-clause
+ -}
+
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE LambdaCase #-}
+{-# OPTIONS_GHC -fno-warn-tabs #-}
+
+module Utility.MoveFile (
+	moveFile,
+) where
+
+import Control.Monad
+import System.FilePath
+import System.PosixCompat.Files hiding (removeLink)
+import System.IO.Error
+import Prelude
+
+#ifndef mingw32_HOST_OS
+import Control.Monad.IfElse
+import Utility.SafeCommand
+#endif
+
+import Utility.SystemDirectory
+import Utility.Tmp
+import Utility.Exception
+import Utility.Monad
+
+{- 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 = viaTmp mv dest ()
+	  where
+		rethrow = throwM e
+
+		mv tmp () = do
+			-- copyFile is likely not as optimised as
+			-- the mv command, so we'll use the command.
+			--
+			-- But, while Windows has a "mv", it does not seem very
+			-- reliable, so use copyFile there.
+#ifndef mingw32_HOST_OS	
+			-- If dest is a directory, mv would move the file
+			-- into it, which is not desired.
+			whenM (isdir dest) rethrow
+			ok <- boolSystem "mv" [Param "-f", Param src, Param tmp]
+			let e' = e
+#else
+			r <- tryIO $ copyFile src tmp
+			let (ok, e') = case r of
+				Left err -> (False, err)
+				Right _ -> (True, e)
+#endif
+			unless ok $ do
+				-- delete any partial
+				_ <- tryIO $ removeFile tmp
+				throwM e'
+
+#ifndef mingw32_HOST_OS	
+	isdir f = do
+		r <- tryIO $ getFileStatus f
+		case r of
+			(Left _) -> return False
+			(Right s) -> return $ isDirectory s
+#endif