hard links on windows

* annex.thin and annex.hardlink are now supported on Windows.
* unannex --fast now makes hard links on Windows.

Annex/Content.hs

@@ -594,14 +594,10 @@ linkOrCopy' canhardlink key src dest = catchBoolIO $
   where
 	hardlink = do
 		s <- getstat
-#ifndef mingw32_HOST_OS
 		if linkCount s > 1
 			then copy s
 			else liftIO (createLink src dest >> return True)
 				`catchIO` const (copy s)
-#else
-		copy s
-#endif
 	copy = checkedCopyFile' key src dest
 	getstat = liftIO $ getFileStatus src
 

Command/Unannex.hs

@@ -5,8 +5,6 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
-{-# LANGUAGE CPP #-}
-
 module Command.Unannex where
 
 import Command
@@ -107,15 +105,11 @@ cleanupIndirect file key = do
 	copyfrom src = 
 		thawContent file `after` liftIO (copyFileExternal CopyAllMetaData src file)
 	hardlinkfrom src =
-#ifndef mingw32_HOST_OS
 		-- creating a hard link could fall; fall back to copying
 		ifM (liftIO $ catchBoolIO $ createLink src file >> return True)
 			( return True
 			, copyfrom src
 			)
-#else
-		copyfrom src
-#endif
 
 performDirect :: FilePath -> Key -> CommandPerform
 performDirect file key = do

Remote/Git.hs

@@ -695,7 +695,6 @@ mkCopier :: Bool -> [CommandParam] -> Annex Copier
 mkCopier remotewanthardlink rsyncparams = do
 	let copier = \src dest p check -> unVerified $
 		rsyncOrCopyFile rsyncparams src dest p <&&> check
-#ifndef mingw32_HOST_OS
 	localwanthardlink <- wantHardLink
 	let linker = \src dest -> createLink src dest >> return True
 	ifM (pure (remotewanthardlink || localwanthardlink) <&&> not <$> isDirect)
@@ -706,6 +705,3 @@ mkCopier remotewanthardlink rsyncparams = do
 				)
 		, return copier
 		)
-#else
-	return $ if remotewanthardlink then copier else copier
-#endif

Utility/CopyFile.hs

@@ -49,13 +49,9 @@ copyFileExternal meta src dest = do
 {- 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

Utility/PosixFiles.hs

@@ -1,6 +1,6 @@
 {- POSIX files (and compatablity wrappers).
  -
- - This is like System.PosixCompat.Files, except with a fixed rename.
+ - This is like System.PosixCompat.Files, but with a few fixes.
  -
  - Copyright 2014 Joey Hess <id@joeyh.name>
  -
@@ -21,6 +21,7 @@ import System.PosixCompat.Files as X hiding (rename)
 import System.Posix.Files (rename)
 #else
 import qualified System.Win32.File as Win32
+import qualified System.Win32.HardLink as Win32
 #endif
 
 {- System.PosixCompat.Files.rename on Windows calls renameFile,
@@ -32,3 +33,10 @@ import qualified System.Win32.File as Win32
 rename :: FilePath -> FilePath -> IO ()
 rename src dest = Win32.moveFileEx src dest Win32.mOVEFILE_REPLACE_EXISTING
 #endif
+
+{- System.PosixCompat.Files.createLink throws an error, but windows
+ - does support hard links. -}
+#ifdef mingw32_HOST_OS
+createLink :: FilePath -> FilePath -> IO ()
+createLink = Win32.createHardLink
+#endif

debian/changelog

@@ -14,6 +14,8 @@ git-annex (6.20160319) UNRELEASED; urgency=medium
   * log --raw-date: Use to display seconds from unix epoch.
   * v6: Close pointer file handles more quickly, to avoid problems on Windows.
   * sync: Show output of git commit.
+  * annex.thin and annex.hardlink are now supported on Windows.
+  * unannex --fast now makes hard links on Windows.
 
  -- Joey Hess <id@joeyh.name>  Wed, 23 Mar 2016 11:42:36 -0400
 

doc/design/adjusted_branches.mdwn

@@ -280,9 +280,20 @@ into adjusted view worktrees.]
   to checkout the adjusted branch some other way. Maybe generalize so this
   more efficient checkout is available as a git-annex command?
 * There are potentially races in code that assumes a branch like
-  master is not being changed by someone else. In particular,
-  propigateAdjustedCommits rebases the adjusted branch on top of master.
-  That is called by sync. The assumption is that any changes in master
-  have already been handled by updateAdjustedBranch. But, if another remote
-  pushed a new master at just the right time, the adjusted branch could be
-  rebased on top of a master that it doesn't incorporate, which is wrong.
+  master is not being changed by someone else. 
+  
+  In particular, propigateAdjustedCommits rebases the adjusted branch on
+  top of master. That is called by sync. The assumption is that any changes
+  in master have already been handled by updateAdjustedBranch. But, if
+  another remote pushed a new master at just the right time, the adjusted
+  branch could be rebased on top of a master that it doesn't incorporate,
+  which is wrong.
+
+  Best fix seems to be to use a hidden ref, like refs/annex/adjusted/master
+  and copy master's ref to it when entering the view branch. Then, make
+  all adjustments via that ref, and propigate back to refs/heads/master.
+
+  It's fine to overwrite changes that were pushed to master when
+  propigating from the adjusted branch. Synced changes also go to
+  synced/master so won't be lost. Pushes not made using git-annex sync
+  of master are not really desired, just a possibility.

doc/tips/unlocked_files.mdwn

@@ -143,7 +143,7 @@ match the new setting:
 	git annex fix
 
 Note that setting annex.thin only has any effect on systems that support
-hard links. Ie, not Windows, and not FAT filesystems.
+hard links. It is supported on Windows, but not on FAT filesystems.
 
 ## tradeoffs