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diff --git a/Annex/Branch.hs b/Annex/Branch.hs
new file mode 100644
index 000000000..9838af25f
--- /dev/null
+++ b/Annex/Branch.hs
@@ -0,0 +1,533 @@
+{- management of the git-annex branch
+ -
+ - Copyright 2011-2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Annex.Branch (
+	fullname,
+	name,
+	hasOrigin,
+	hasSibling,
+	siblingBranches,
+	create,
+	update,
+	forceUpdate,
+	updateTo,
+	get,
+	change,
+	commit,
+	forceCommit,
+	files,
+	withIndex,
+	performTransitions,
+) where
+
+import qualified Data.ByteString.Lazy.Char8 as L
+import qualified Data.Set as S
+import qualified Data.Map as M
+import qualified Control.Exception as E
+
+import Common.Annex
+import Annex.BranchState
+import Annex.Journal
+import qualified Git
+import qualified Git.Command
+import qualified Git.Ref
+import qualified Git.Sha
+import qualified Git.Branch
+import qualified Git.UnionMerge
+import qualified Git.UpdateIndex
+import Git.HashObject
+import Git.Types
+import Git.FilePath
+import Annex.CatFile
+import Annex.Perms
+import qualified Annex
+import Utility.Env
+import Logs
+import Logs.Transitions
+import Logs.Trust.Pure
+import Annex.ReplaceFile
+import qualified Annex.Queue
+import Annex.Branch.Transitions
+import Annex.Exception
+
+{- Name of the branch that is used to store git-annex's information. -}
+name :: Git.Ref
+name = Git.Ref "git-annex"
+
+{- Fully qualified name of the branch. -}
+fullname :: Git.Ref
+fullname = Git.Ref $ "refs/heads/" ++ show name
+
+{- Branch's name in origin. -}
+originname :: Git.Ref
+originname = Git.Ref $ "origin/" ++ show name
+
+{- Does origin/git-annex exist? -}
+hasOrigin :: Annex Bool
+hasOrigin = inRepo $ Git.Ref.exists originname
+
+{- Does the git-annex branch or a sibling foo/git-annex branch exist? -}
+hasSibling :: Annex Bool
+hasSibling = not . null <$> siblingBranches
+
+{- List of git-annex (refs, branches), including the main one and any
+ - from remotes. Duplicate refs are filtered out. -}
+siblingBranches :: Annex [(Git.Ref, Git.Branch)]
+siblingBranches = inRepo $ Git.Ref.matchingUniq [name]
+
+{- Creates the branch, if it does not already exist. -}
+create :: Annex ()
+create = void getBranch
+
+{- Returns the ref of the branch, creating it first if necessary. -}
+getBranch :: Annex Git.Ref
+getBranch = maybe (hasOrigin >>= go >>= use) return =<< branchsha
+  where
+	go True = do
+		inRepo $ Git.Command.run
+			[Param "branch", Param $ show name, Param $ show originname]
+		fromMaybe (error $ "failed to create " ++ show name)
+			<$> branchsha
+	go False = withIndex' True $
+		inRepo $ Git.Branch.commit "branch created" fullname []
+	use sha = do
+		setIndexSha sha
+		return sha
+	branchsha = inRepo $ Git.Ref.sha fullname
+
+{- Ensures that the branch and index are up-to-date; should be
+ - called before data is read from it. Runs only once per git-annex run. -}
+update :: Annex ()
+update = runUpdateOnce $ void $ updateTo =<< siblingBranches
+
+{- Forces an update even if one has already been run. -}
+forceUpdate :: Annex Bool
+forceUpdate = updateTo =<< siblingBranches
+
+{- Merges the specified Refs into the index, if they have any changes not
+ - already in it. The Branch names are only used in the commit message;
+ - it's even possible that the provided Branches have not been updated to
+ - point to the Refs yet.
+ - 
+ - The branch is fast-forwarded if possible, otherwise a merge commit is
+ - made.
+ -
+ - Before Refs are merged into the index, it's important to first stage the
+ - journal into the index. Otherwise, any changes in the journal would
+ - later get staged, and might overwrite changes made during the merge.
+ - This is only done if some of the Refs do need to be merged.
+ -
+ - Also handles performing any Transitions that have not yet been
+ - performed, in either the local branch, or the Refs.
+ -
+ - Returns True if any refs were merged in, False otherwise.
+ -}
+updateTo :: [(Git.Ref, Git.Branch)] -> Annex Bool
+updateTo pairs = do
+	-- ensure branch exists, and get its current ref
+	branchref <- getBranch
+	dirty <- journalDirty
+	ignoredrefs <- getIgnoredRefs
+	(refs, branches) <- unzip <$> filterM (isnewer ignoredrefs) pairs
+	if null refs
+		{- Even when no refs need to be merged, the index
+		 - may still be updated if the branch has gotten ahead 
+		 - of the index. -}
+		then whenM (needUpdateIndex branchref) $ lockJournal $ \jl -> do
+			forceUpdateIndex jl branchref
+			{- When there are journalled changes
+			 - as well as the branch being updated,
+			 - a commit needs to be done. -}
+			when dirty $
+				go branchref True [] [] jl
+		else lockJournal $ go branchref dirty refs branches
+	return $ not $ null refs
+  where
+	isnewer ignoredrefs (r, _)
+		| S.member r ignoredrefs = return False
+		| otherwise = inRepo $ Git.Branch.changed fullname r
+	go branchref dirty refs branches jl = withIndex $ do
+		cleanjournal <- if dirty then stageJournal jl else return noop
+		let merge_desc = if null branches
+			then "update"
+			else "merging " ++
+				unwords (map Git.Ref.describe branches) ++ 
+				" into " ++ show name
+		localtransitions <- parseTransitionsStrictly "local"
+			<$> getLocal transitionsLog
+		unless (null branches) $ do
+			showSideAction merge_desc
+			mergeIndex jl refs
+		let commitrefs = nub $ fullname:refs
+		unlessM (handleTransitions jl localtransitions commitrefs) $ do
+			ff <- if dirty
+				then return False
+				else inRepo $ Git.Branch.fastForward fullname refs
+			if ff
+				then updateIndex jl branchref
+				else commitIndex jl branchref merge_desc commitrefs
+		liftIO cleanjournal
+
+{- Gets the content of a file, which may be in the journal, or in the index
+ - (and committed to the branch).
+ - 
+ - Updates the branch if necessary, to ensure the most up-to-date available
+ - content is returned.
+ -
+ - Returns an empty string if the file doesn't exist yet. -}
+get :: FilePath -> Annex String
+get file = do
+	update
+	getLocal file
+
+{- Like get, but does not merge the branch, so the info returned may not
+ - reflect changes in remotes.
+ - (Changing the value this returns, and then merging is always the
+ - same as using get, and then changing its value.) -}
+getLocal :: FilePath -> Annex String
+getLocal file = go =<< getJournalFileStale file
+  where
+	go (Just journalcontent) = return journalcontent
+	go Nothing = getRaw file
+
+getRaw :: FilePath -> Annex String
+getRaw file = withIndex $ L.unpack <$> catFile fullname file
+
+{- Applies a function to modifiy the content of a file.
+ -
+ - Note that this does not cause the branch to be merged, it only
+ - modifes the current content of the file on the branch.
+ -}
+change :: FilePath -> (String -> String) -> Annex ()
+change file a = lockJournal $ \jl -> a <$> getLocal file >>= set jl file
+
+{- Records new content of a file into the journal -}
+set :: JournalLocked -> FilePath -> String -> Annex ()
+set = setJournalFile
+
+{- Stages the journal, and commits staged changes to the branch. -}
+commit :: String -> Annex ()
+commit = whenM journalDirty . forceCommit
+
+{- Commits the current index to the branch even without any journalleda
+ - changes. -}
+forceCommit :: String -> Annex ()
+forceCommit message = lockJournal $ \jl -> do
+	cleanjournal <- stageJournal jl
+	ref <- getBranch
+	withIndex $ commitIndex jl ref message [fullname]
+	liftIO cleanjournal
+
+{- Commits the staged changes in the index to the branch.
+ - 
+ - Ensures that the branch's index file is first updated to the state
+ - of the branch at branchref, before running the commit action. This
+ - is needed because the branch may have had changes pushed to it, that
+ - are not yet reflected in the index.
+ -
+ - Also safely handles a race that can occur if a change is being pushed
+ - into the branch at the same time. When the race happens, the commit will
+ - be made on top of the newly pushed change, but without the index file
+ - being updated to include it. The result is that the newly pushed
+ - change is reverted. This race is detected and another commit made
+ - to fix it.
+ - 
+ - The branchref value can have been obtained using getBranch at any
+ - previous point, though getting it a long time ago makes the race
+ - more likely to occur.
+ -}
+commitIndex :: JournalLocked -> Git.Ref -> String -> [Git.Ref] -> Annex ()
+commitIndex jl branchref message parents = do
+	showStoringStateAction
+	commitIndex' jl branchref message parents
+commitIndex' :: JournalLocked -> Git.Ref -> String -> [Git.Ref] -> Annex ()
+commitIndex' jl branchref message parents = do
+	updateIndex jl branchref
+	committedref <- inRepo $ Git.Branch.commit message fullname parents
+	setIndexSha committedref
+	parentrefs <- commitparents <$> catObject committedref
+	when (racedetected branchref parentrefs) $ do
+		liftIO $ print ("race detected", branchref, parentrefs, "committing", (branchref, parents))
+		fixrace committedref parentrefs
+  where
+	-- look for "parent ref" lines and return the refs
+	commitparents = map (Git.Ref . snd) . filter isparent .
+		map (toassoc . L.unpack) . L.lines
+	toassoc = separate (== ' ')
+	isparent (k,_) = k == "parent"
+		
+	{- The race can be detected by checking the commit's
+	 - parent, which will be the newly pushed branch,
+	 - instead of the expected ref that the index was updated to. -}
+	racedetected expectedref parentrefs
+		| expectedref `elem` parentrefs = False -- good parent
+		| otherwise = True -- race!
+		
+	{- To recover from the race, union merge the lost refs
+	 - into the index, and recommit on top of the bad commit. -}
+	fixrace committedref lostrefs = do
+		mergeIndex jl lostrefs
+		commitIndex jl committedref racemessage [committedref]
+		
+	racemessage = message ++ " (recovery from race)"
+
+{- Lists all files on the branch. There may be duplicates in the list. -}
+files :: Annex [FilePath]
+files = do
+	update
+	(++)
+		<$> branchFiles
+		<*> getJournalledFilesStale
+
+{- Files in the branch, not including any from journalled changes,
+ - and without updating the branch. -}
+branchFiles :: Annex [FilePath]
+branchFiles = withIndex $ inRepo $ Git.Command.pipeNullSplitZombie
+	[ Params "ls-tree --name-only -r -z"
+	, Param $ show fullname
+	]
+
+{- Populates the branch's index file with the current branch contents.
+ - 
+ - This is only done when the index doesn't yet exist, and the index 
+ - is used to build up changes to be commited to the branch, and merge
+ - in changes from other branches.
+ -}
+genIndex :: Git.Repo -> IO ()
+genIndex g = Git.UpdateIndex.streamUpdateIndex g
+	[Git.UpdateIndex.lsTree fullname g]
+
+{- Merges the specified refs into the index.
+ - Any changes staged in the index will be preserved. -}
+mergeIndex :: JournalLocked -> [Git.Ref] -> Annex ()
+mergeIndex jl branches = do
+	prepareModifyIndex jl
+	h <- catFileHandle
+	inRepo $ \g -> Git.UnionMerge.mergeIndex h g branches
+
+{- Removes any stale git lock file, to avoid git falling over when
+ - updating the index.
+ -
+ - Since all modifications of the index are performed inside this module,
+ - and only when the journal is locked, the fact that the journal has to be
+ - locked when this is called ensures that no other process is currently
+ - modifying the index. So any index.lock file must be stale, caused
+ - by git running when the system crashed, or the repository's disk was
+ - removed, etc.
+ -}
+prepareModifyIndex :: JournalLocked -> Annex ()
+prepareModifyIndex _jl = do
+	index <- fromRepo gitAnnexIndex
+	void $ liftIO $ tryIO $ removeFile $ index ++ ".lock"
+
+{- Runs an action using the branch's index file. -}
+withIndex :: Annex a -> Annex a
+withIndex = withIndex' False
+withIndex' :: Bool -> Annex a -> Annex a
+withIndex' bootstrapping a = do
+	f <- fromRepo gitAnnexIndex
+	g <- gitRepo
+#ifdef __ANDROID__
+	{- This should not be necessary on Android, but there is some
+	 - weird getEnvironment breakage. See
+	 - https://github.com/neurocyte/ghc-android/issues/7
+	 - Use getEnv to get some key environment variables that
+	 - git expects to have. -}
+	let keyenv = words "USER PATH GIT_EXEC_PATH HOSTNAME HOME"
+	let getEnvPair k = maybe Nothing (\v -> Just (k, v)) <$> getEnv k
+	e <- liftIO $ catMaybes <$> forM keyenv getEnvPair
+#else
+	e <- liftIO getEnvironment
+#endif
+	let g' = g { gitEnv = Just $ ("GIT_INDEX_FILE", f):e }
+
+	r <- tryAnnex $ do
+		Annex.changeState $ \s -> s { Annex.repo = g' }
+		checkIndexOnce $ unlessM (liftIO $ doesFileExist f) $ do
+			unless bootstrapping create
+			createAnnexDirectory $ takeDirectory f
+			unless bootstrapping $ inRepo genIndex
+		a
+	Annex.changeState $ \s -> s { Annex.repo = (Annex.repo s) { gitEnv = gitEnv g} }
+	either E.throw return r
+
+{- Updates the branch's index to reflect the current contents of the branch.
+ - Any changes staged in the index will be preserved.
+ -
+ - Compares the ref stored in the lock file with the current
+ - ref of the branch to see if an update is needed.
+ -}
+updateIndex :: JournalLocked -> Git.Ref -> Annex ()
+updateIndex jl branchref = whenM (needUpdateIndex branchref) $
+	forceUpdateIndex jl branchref
+
+forceUpdateIndex :: JournalLocked -> Git.Ref -> Annex ()
+forceUpdateIndex jl branchref = do
+	withIndex $ mergeIndex jl [fullname]
+	setIndexSha branchref
+
+{- Checks if the index needs to be updated. -}
+needUpdateIndex :: Git.Ref -> Annex Bool
+needUpdateIndex branchref = do
+	f <- fromRepo gitAnnexIndexStatus
+	committedref <- Git.Ref . firstLine <$>
+		liftIO (catchDefaultIO "" $ readFileStrict f)
+	return (committedref /= branchref)
+
+{- Record that the branch's index has been updated to correspond to a
+ - given ref of the branch. -}
+setIndexSha :: Git.Ref -> Annex ()
+setIndexSha ref = do
+	f <- fromRepo gitAnnexIndexStatus
+	liftIO $ writeFile f $ show ref ++ "\n"
+	setAnnexFilePerm f
+
+{- Stages the journal into the index and returns an action that will
+ - clean up the staged journal files, which should only be run once
+ - the index has been committed to the branch.
+ -
+ - Before staging, this removes any existing git index file lock.
+ - This is safe to do because stageJournal is the only thing that
+ - modifies this index file, and only one can run at a time, because
+ - the journal is locked. So any existing git index file lock must be
+ - stale, and the journal must contain any data that was in the process
+ - of being written to the index file when it crashed.
+ -}
+stageJournal :: JournalLocked -> Annex (IO ())
+stageJournal jl = withIndex $ do
+	prepareModifyIndex jl
+	g <- gitRepo
+	let dir = gitAnnexJournalDir g
+	fs <- getJournalFiles jl
+	liftIO $ do
+		h <- hashObjectStart g
+		Git.UpdateIndex.streamUpdateIndex g
+			[genstream dir h fs]
+		hashObjectStop h
+	return $ liftIO $ mapM_ (removeFile . (dir </>)) fs
+  where
+	genstream dir h fs streamer = forM_ fs $ \file -> do
+		let path = dir </> file
+		sha <- hashFile h path
+		streamer $ Git.UpdateIndex.updateIndexLine
+			sha FileBlob (asTopFilePath $ fileJournal file)
+
+{- This is run after the refs have been merged into the index,
+ - but before the result is committed to the branch.
+ - (Which is why it's passed the contents of the local branches's
+ - transition log before that merge took place.)
+ -
+ - When the refs contain transitions that have not yet been done locally,
+ - the transitions are performed on the index, and a new branch
+ - is created from the result.
+ -
+ - When there are transitions recorded locally that have not been done
+ - to the remote refs, the transitions are performed in the index,
+ - and committed to the existing branch. In this case, the untransitioned
+ - remote refs cannot be merged into the branch (since transitions
+ - throw away history), so they are added to the list of refs to ignore,
+ - to avoid re-merging content from them again.
+ -}
+handleTransitions :: JournalLocked -> Transitions -> [Git.Ref] -> Annex Bool
+handleTransitions jl localts refs = do
+	m <- M.fromList <$> mapM getreftransition refs
+	let remotets = M.elems m
+	if all (localts ==) remotets
+		then return False
+		else do
+			let allts = combineTransitions (localts:remotets)
+			let (transitionedrefs, untransitionedrefs) =
+				partition (\r -> M.lookup r m == Just allts) refs
+			performTransitionsLocked jl allts (localts /= allts) transitionedrefs
+			ignoreRefs untransitionedrefs
+			return True
+  where
+  	getreftransition ref = do
+		ts <- parseTransitionsStrictly "remote" . L.unpack
+			<$> catFile ref transitionsLog
+		return (ref, ts)
+
+ignoreRefs :: [Git.Ref] -> Annex ()
+ignoreRefs rs = do
+	old <- getIgnoredRefs
+	let s = S.unions [old, S.fromList rs]
+	f <- fromRepo gitAnnexIgnoredRefs
+	replaceFile f $ \tmp -> liftIO $ writeFile tmp $
+		unlines $ map show $ S.elems s
+
+getIgnoredRefs :: Annex (S.Set Git.Ref)
+getIgnoredRefs = S.fromList . mapMaybe Git.Sha.extractSha . lines <$> content
+  where
+  	content = do
+		f <- fromRepo gitAnnexIgnoredRefs
+		liftIO $ catchDefaultIO "" $ readFile f
+
+{- Performs the specified transitions on the contents of the index file,
+ - commits it to the branch, or creates a new branch.
+ -}
+performTransitions :: Transitions -> Bool -> [Ref] -> Annex ()
+performTransitions ts neednewlocalbranch transitionedrefs = lockJournal $ \jl ->
+	performTransitionsLocked jl ts neednewlocalbranch transitionedrefs
+performTransitionsLocked :: JournalLocked -> Transitions -> Bool -> [Ref] -> Annex ()
+performTransitionsLocked jl ts neednewlocalbranch transitionedrefs = do
+	-- For simplicity & speed, we're going to use the Annex.Queue to
+	-- update the git-annex branch, while it usually holds changes
+	-- for the head branch. Flush any such changes.
+	Annex.Queue.flush
+	withIndex $ do
+		prepareModifyIndex jl
+		run $ mapMaybe getTransitionCalculator $ transitionList ts
+		Annex.Queue.flush
+		if neednewlocalbranch
+			then do
+				committedref <- inRepo $ Git.Branch.commit message fullname transitionedrefs
+				setIndexSha committedref
+			else do
+				ref <- getBranch
+				commitIndex jl ref message (nub $ fullname:transitionedrefs)
+  where
+  	message
+		| neednewlocalbranch && null transitionedrefs = "new branch for transition " ++ tdesc
+		| otherwise = "continuing transition " ++ tdesc
+	tdesc = show $ map describeTransition $ transitionList ts
+
+	{- The changes to make to the branch are calculated and applied to
+	 - the branch directly, rather than going through the journal,
+	 - which would be innefficient. (And the journal is not designed
+	 - to hold changes to every file in the branch at once.)
+	 -
+	 - When a file in the branch is changed by transition code,
+	 - that value is remembered and fed into the code for subsequent
+	 - transitions.
+	 -}
+	run [] = noop
+	run changers = do
+		trustmap <- calcTrustMap <$> getRaw trustLog
+		fs <- branchFiles
+		hasher <- inRepo hashObjectStart
+		forM_ fs $ \f -> do
+			content <- getRaw f
+			apply changers hasher f content trustmap
+		liftIO $ hashObjectStop hasher
+	apply [] _ _ _ _ = return ()
+	apply (changer:rest) hasher file content trustmap =
+		case changer file content trustmap of
+			RemoveFile -> do
+				Annex.Queue.addUpdateIndex
+					=<< inRepo (Git.UpdateIndex.unstageFile file)
+				-- File is deleted; can't run any other
+				-- transitions on it.
+				return ()
+			ChangeFile content' -> do
+				sha <- inRepo $ hashObject BlobObject content'
+				Annex.Queue.addUpdateIndex $ Git.UpdateIndex.pureStreamer $
+					Git.UpdateIndex.updateIndexLine sha FileBlob (asTopFilePath file)
+				apply rest hasher file content' trustmap
+			PreserveFile ->
+				apply rest hasher file content trustmap
diff --git a/Annex/Branch/Transitions.hs b/Annex/Branch/Transitions.hs
new file mode 100644
index 000000000..90002de62
--- /dev/null
+++ b/Annex/Branch/Transitions.hs
@@ -0,0 +1,53 @@
+{- git-annex branch transitions
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Branch.Transitions (
+	FileTransition(..),
+	getTransitionCalculator
+) where
+
+import Logs
+import Logs.Transitions
+import Logs.UUIDBased as UUIDBased
+import Logs.Presence.Pure as Presence
+import Types.TrustLevel
+import Types.UUID
+
+import qualified Data.Map as M
+
+data FileTransition
+	= ChangeFile String
+	| RemoveFile
+	| PreserveFile
+
+type TransitionCalculator = FilePath -> String -> TrustMap -> FileTransition
+
+getTransitionCalculator :: Transition -> Maybe TransitionCalculator
+getTransitionCalculator ForgetGitHistory = Nothing
+getTransitionCalculator ForgetDeadRemotes = Just dropDead
+
+dropDead :: FilePath -> String -> TrustMap -> FileTransition
+dropDead f content trustmap = case getLogVariety f of
+	Just UUIDBasedLog -> ChangeFile $
+		UUIDBased.showLog id $ dropDeadFromUUIDBasedLog trustmap $ UUIDBased.parseLog Just content
+	Just (PresenceLog _) ->
+		let newlog = Presence.compactLog $ dropDeadFromPresenceLog trustmap $ Presence.parseLog content
+		in if null newlog
+			then RemoveFile
+			else ChangeFile $ Presence.showLog newlog
+	Nothing -> PreserveFile
+
+dropDeadFromUUIDBasedLog :: TrustMap -> UUIDBased.Log String -> UUIDBased.Log String
+dropDeadFromUUIDBasedLog trustmap = M.filterWithKey $ notDead trustmap . const
+
+{- Presence logs can contain UUIDs or other values. Any line that matches
+ - a dead uuid is dropped; any other values are passed through. -}
+dropDeadFromPresenceLog :: TrustMap -> [Presence.LogLine] -> [Presence.LogLine]
+dropDeadFromPresenceLog trustmap = filter $ notDead trustmap (toUUID . Presence.info)
+
+notDead :: TrustMap -> (v -> UUID) -> v -> Bool
+notDead trustmap a v = M.findWithDefault SemiTrusted (a v) trustmap /= DeadTrusted
diff --git a/Annex/BranchState.hs b/Annex/BranchState.hs
new file mode 100644
index 000000000..9b2f9a04c
--- /dev/null
+++ b/Annex/BranchState.hs
@@ -0,0 +1,43 @@
+{- git-annex branch state management
+ -
+ - Runtime state about the git-annex branch.
+ -
+ - Copyright 2011-2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.BranchState where
+
+import Common.Annex
+import Types.BranchState
+import qualified Annex
+
+getState :: Annex BranchState
+getState = Annex.getState Annex.branchstate
+
+setState :: BranchState -> Annex ()
+setState state = Annex.changeState $ \s -> s { Annex.branchstate = state }
+
+changeState :: (BranchState -> BranchState) -> Annex ()
+changeState changer = setState =<< changer <$> getState
+
+{- Runs an action to check that the index file exists, if it's not been
+ - checked before in this run of git-annex. -}
+checkIndexOnce :: Annex () -> Annex ()
+checkIndexOnce a = unlessM (indexChecked <$> getState) $ do
+	a
+	changeState $ \s -> s { indexChecked = True }
+
+{- Runs an action to update the branch, if it's not been updated before
+ - in this run of git-annex. -}
+runUpdateOnce :: Annex () -> Annex ()
+runUpdateOnce a = unlessM (branchUpdated <$> getState) $ do
+	a
+	disableUpdate
+
+{- Avoids updating the branch. A useful optimisation when the branch
+ - is known to have not changed, or git-annex won't be relying on info
+ - from it. -}
+disableUpdate :: Annex ()
+disableUpdate = changeState $ \s -> s { branchUpdated = True }
diff --git a/Annex/CatFile.hs b/Annex/CatFile.hs
new file mode 100644
index 000000000..812d032c6
--- /dev/null
+++ b/Annex/CatFile.hs
@@ -0,0 +1,139 @@
+{- git cat-file interface, with handle automatically stored in the Annex monad
+ -
+ - Copyright 2011-2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.CatFile (
+	catFile,
+	catObject,
+	catTree,
+	catObjectDetails,
+	catFileHandle,
+	catKey,
+	catKeyFile,
+	catKeyFileHEAD,
+) where
+
+import qualified Data.ByteString.Lazy as L
+import qualified Data.Map as M
+import System.PosixCompat.Types
+
+import Common.Annex
+import qualified Git
+import qualified Git.CatFile
+import qualified Annex
+import Git.Types
+import Git.FilePath
+import Git.FileMode
+import qualified Git.Ref
+
+catFile :: Git.Branch -> FilePath -> Annex L.ByteString
+catFile branch file = do
+	h <- catFileHandle
+	liftIO $ Git.CatFile.catFile h branch file
+
+catObject :: Git.Ref -> Annex L.ByteString
+catObject ref = do
+	h <- catFileHandle
+	liftIO $ Git.CatFile.catObject h ref
+
+catTree :: Git.Ref -> Annex [(FilePath, FileMode)]
+catTree ref = do
+	h <- catFileHandle
+	liftIO $ Git.CatFile.catTree h ref
+
+catObjectDetails :: Git.Ref -> Annex (Maybe (L.ByteString, Sha, ObjectType))
+catObjectDetails ref = do
+	h <- catFileHandle
+	liftIO $ Git.CatFile.catObjectDetails h ref
+
+{- There can be multiple index files, and a different cat-file is needed
+ - for each. This is selected by setting GIT_INDEX_FILE in the gitEnv. -}
+catFileHandle :: Annex Git.CatFile.CatFileHandle
+catFileHandle = do
+	m <- Annex.getState Annex.catfilehandles
+	indexfile <- fromMaybe "" . maybe Nothing (lookup "GIT_INDEX_FILE")
+		<$> fromRepo gitEnv
+	case M.lookup indexfile m of
+		Just h -> return h
+		Nothing -> do
+			h <- inRepo Git.CatFile.catFileStart
+			let m' = M.insert indexfile h m
+			Annex.changeState $ \s -> s { Annex.catfilehandles = m' }
+			return h
+
+{- From the Sha or Ref of a symlink back to the key.
+ -
+ - Requires a mode witness, to guarantee that the file is a symlink.
+ -}
+catKey :: Ref -> FileMode -> Annex (Maybe Key)
+catKey = catKey' True
+
+catKey' :: Bool -> Ref -> FileMode -> Annex (Maybe Key)
+catKey' modeguaranteed ref mode
+	| isSymLink mode = do
+		l <- fromInternalGitPath . encodeW8 . L.unpack <$> get
+		return $ if isLinkToAnnex l
+			then fileKey $ takeFileName l
+			else Nothing
+	| otherwise = return Nothing
+  where
+  	-- If the mode is not guaranteed to be correct, avoid
+	-- buffering the whole file content, which might be large.
+	-- 8192 is enough if it really is a symlink.
+  	get
+		| modeguaranteed = catObject ref
+		| otherwise = L.take 8192 <$> catObject ref
+
+{- Looks up the file mode corresponding to the Ref using the running
+ - cat-file.
+ -
+ - Currently this always has to look in HEAD, because cat-file --batch
+ - does not offer a way to specify that we want to look up a tree object
+ - in the index. So if the index has a file staged not as a symlink,
+ - and it is a symlink in head, the wrong mode is gotten.
+ - Also, we have to assume the file is a symlink if it's not yet committed
+ - to HEAD. For these reasons, modeguaranteed is not set.
+ -}
+catKeyChecked :: Bool -> Ref -> Annex (Maybe Key)
+catKeyChecked needhead ref@(Ref r) =
+	catKey' False ref =<< findmode <$> catTree treeref
+  where
+  	pathparts = split "/" r
+	dir = intercalate "/" $ take (length pathparts - 1) pathparts
+	file = fromMaybe "" $ lastMaybe pathparts
+	treeref = Ref $ if needhead then "HEAD" ++ dir ++ "/" else dir ++ "/"
+	findmode = fromMaybe symLinkMode . headMaybe .
+		 map snd . filter (\p -> fst p == file)
+
+{- From a file in the repository back to the key.
+ -
+ - Ideally, this should reflect the key that's staged in the index,
+ - not the key that's committed to HEAD. Unfortunately, git cat-file
+ - does not refresh the index file after it's started up, so things
+ - newly staged in the index won't show up. It does, however, notice
+ - when branches change.
+ -
+ - For command-line git-annex use, that doesn't matter. It's perfectly
+ - reasonable for things staged in the index after the currently running
+ - git-annex process to not be noticed by it. However, we do want to see
+ - what's in the index, since it may have uncommitted changes not in HEAD>
+ -
+ - For the assistant, this is much more of a problem, since it commits
+ - files and then needs to be able to immediately look up their keys.
+ - OTOH, the assistant doesn't keep changes staged in the index for very
+ - long at all before committing them -- and it won't look at the keys
+ - of files until after committing them.
+ -
+ - So, this gets info from the index, unless running as a daemon.
+ -}
+catKeyFile :: FilePath -> Annex (Maybe Key)
+catKeyFile f = ifM (Annex.getState Annex.daemon)
+	( catKeyFileHEAD f
+	, catKeyChecked True $ Git.Ref.fileRef f
+	)
+
+catKeyFileHEAD :: FilePath -> Annex (Maybe Key)
+catKeyFileHEAD f = catKeyChecked False $ Git.Ref.fileFromRef Git.Ref.headRef f
diff --git a/Annex/CheckAttr.hs b/Annex/CheckAttr.hs
new file mode 100644
index 000000000..8eed9e804
--- /dev/null
+++ b/Annex/CheckAttr.hs
@@ -0,0 +1,35 @@
+{- git check-attr interface, with handle automatically stored in the Annex monad
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.CheckAttr (
+	checkAttr,
+	checkAttrHandle
+) where
+
+import Common.Annex
+import qualified Git.CheckAttr as Git
+import qualified Annex
+
+{- All gitattributes used by git-annex. -}
+annexAttrs :: [Git.Attr]
+annexAttrs =
+	[ "annex.backend"
+	, "annex.numcopies"
+	]
+
+checkAttr :: Git.Attr -> FilePath -> Annex String
+checkAttr attr file = do
+	h <- checkAttrHandle
+	liftIO $ Git.checkAttr h attr file
+
+checkAttrHandle :: Annex Git.CheckAttrHandle
+checkAttrHandle = maybe startup return =<< Annex.getState Annex.checkattrhandle
+  where
+	startup = do
+		h <- inRepo $ Git.checkAttrStart annexAttrs
+		Annex.changeState $ \s -> s { Annex.checkattrhandle = Just h }
+		return h
diff --git a/Annex/CheckIgnore.hs b/Annex/CheckIgnore.hs
new file mode 100644
index 000000000..d45e652bc
--- /dev/null
+++ b/Annex/CheckIgnore.hs
@@ -0,0 +1,32 @@
+{- git check-ignore interface, with handle automatically stored in
+ - the Annex monad
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.CheckIgnore (
+	checkIgnored,
+	checkIgnoreHandle
+) where
+
+import Common.Annex
+import qualified Git.CheckIgnore as Git
+import qualified Annex
+
+checkIgnored :: FilePath -> Annex Bool
+checkIgnored file = go =<< checkIgnoreHandle
+  where
+  	go Nothing = return False
+	go (Just h) = liftIO $ Git.checkIgnored h file
+
+checkIgnoreHandle :: Annex (Maybe Git.CheckIgnoreHandle)
+checkIgnoreHandle = maybe startup return =<< Annex.getState Annex.checkignorehandle
+  where
+	startup = do
+		v <- inRepo Git.checkIgnoreStart
+		when (isNothing v) $
+			warning "The installed version of git is too old for .gitignores to be honored by git-annex."
+		Annex.changeState $ \s -> s { Annex.checkignorehandle = Just v }
+		return v
diff --git a/Annex/Content.hs b/Annex/Content.hs
new file mode 100644
index 000000000..62f1b1ccb
--- /dev/null
+++ b/Annex/Content.hs
@@ -0,0 +1,529 @@
+{- git-annex file content managing
+ -
+ - Copyright 2010-2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Annex.Content (
+	inAnnex,
+	inAnnexSafe,
+	inAnnexCheck,
+	lockContent,
+	getViaTmp,
+	getViaTmpChecked,
+	getViaTmpUnchecked,
+	withTmp,
+	checkDiskSpace,
+	moveAnnex,
+	sendAnnex,
+	prepSendAnnex,
+	removeAnnex,
+	fromAnnex,
+	moveBad,
+	getKeysPresent,
+	saveState,
+	downloadUrl,
+	preseedTmp,
+	freezeContent,
+	thawContent,
+	dirKeys,
+	withObjectLoc,
+) where
+
+import System.IO.Unsafe (unsafeInterleaveIO)
+import System.PosixCompat.Files
+
+import Common.Annex
+import Logs.Location
+import qualified Git
+import qualified Annex
+import qualified Annex.Queue
+import qualified Annex.Branch
+import Utility.DiskFree
+import Utility.FileMode
+import qualified Annex.Url as Url
+import Types.Key
+import Utility.DataUnits
+import Utility.CopyFile
+import Config
+import Git.SharedRepository
+import Annex.Perms
+import Annex.Link
+import Annex.Content.Direct
+import Annex.ReplaceFile
+import Annex.Exception
+
+{- Checks if a given key's content is currently present. -}
+inAnnex :: Key -> Annex Bool
+inAnnex key = inAnnexCheck key $ liftIO . doesFileExist
+
+{- Runs an arbitrary check on a key's content. -}
+inAnnexCheck :: Key -> (FilePath -> Annex Bool) -> Annex Bool
+inAnnexCheck key check = inAnnex' id False check key
+
+{- Generic inAnnex, handling both indirect and direct mode.
+ -
+ - In direct mode, at least one of the associated files must pass the
+ - check. Additionally, the file must be unmodified.
+ -}
+inAnnex' :: (a -> Bool) -> a -> (FilePath -> Annex a) -> Key -> Annex a
+inAnnex' isgood bad check key = withObjectLoc key checkindirect checkdirect
+  where
+	checkindirect loc = do
+		whenM (fromRepo Git.repoIsUrl) $
+			error "inAnnex cannot check remote repo"
+		check loc
+	checkdirect [] = return bad
+	checkdirect (loc:locs) = do
+		r <- check loc
+		if isgood r
+			then ifM (goodContent key loc)
+				( return r
+				, checkdirect locs
+				)
+			else checkdirect locs
+
+{- A safer check; the key's content must not only be present, but
+ - is not in the process of being removed. -}
+inAnnexSafe :: Key -> Annex (Maybe Bool)
+inAnnexSafe = inAnnex' (fromMaybe False) (Just False) go
+  where
+	go f = liftIO $ openforlock f >>= check
+#ifndef mingw32_HOST_OS
+	openforlock f = catchMaybeIO $
+		openFd f ReadOnly Nothing defaultFileFlags
+#else
+	openforlock _ = return $ Just ()
+#endif
+	check Nothing = return is_missing
+#ifndef mingw32_HOST_OS
+	check (Just h) = do
+		v <- getLock h (ReadLock, AbsoluteSeek, 0, 0)
+		closeFd h
+		return $ case v of
+			Just _ -> is_locked
+			Nothing -> is_unlocked
+#else
+	check (Just _) = return is_unlocked
+#endif
+#ifndef mingw32_HOST_OS
+	is_locked = Nothing
+#endif
+	is_unlocked = Just True
+	is_missing = Just False
+
+{- Content is exclusively locked while running an action that might remove
+ - it. (If the content is not present, no locking is done.) -}
+lockContent :: Key -> Annex a -> Annex a
+#ifndef mingw32_HOST_OS
+lockContent key a = do
+	file <- calcRepo $ gitAnnexLocation key
+	bracketIO (openforlock file >>= lock) unlock (const a)
+  where
+	{- Since files are stored with the write bit disabled, have
+	 - to fiddle with permissions to open for an exclusive lock. -}
+	openforlock f = catchMaybeIO $ ifM (doesFileExist f)
+		( withModifiedFileMode f
+			(`unionFileModes` ownerWriteMode)
+			open
+		, open
+		)
+	  where
+		open = openFd f ReadWrite Nothing defaultFileFlags
+	lock Nothing = return Nothing
+	lock (Just fd) = do
+		v <- tryIO $ setLock fd (WriteLock, AbsoluteSeek, 0, 0)
+		case v of
+			Left _ -> error "content is locked"
+			Right _ -> return $ Just fd
+	unlock Nothing = noop
+	unlock (Just l) = closeFd l
+#else
+lockContent _key a = a -- no locking for Windows!
+#endif
+
+{- Runs an action, passing it a temporary filename to get,
+ - and if the action succeeds, moves the temp file into 
+ - the annex as a key's content. -}
+getViaTmp :: Key -> (FilePath -> Annex Bool) -> Annex Bool
+getViaTmp = getViaTmpChecked (return True)
+
+{- Like getViaTmp, but does not check that there is enough disk space
+ - for the incoming key. For use when the key content is already on disk
+ - and not being copied into place. -}
+getViaTmpUnchecked :: Key -> (FilePath -> Annex Bool) -> Annex Bool
+getViaTmpUnchecked = finishGetViaTmp (return True)
+
+getViaTmpChecked :: Annex Bool -> Key -> (FilePath -> Annex Bool) -> Annex Bool
+getViaTmpChecked check key action = do
+	tmp <- fromRepo $ gitAnnexTmpLocation key
+
+	-- Check that there is enough free disk space.
+	-- When the temp file already exists, count the space
+	-- it is using as free.
+	e <- liftIO $ doesFileExist tmp
+	alreadythere <- if e
+		then fromIntegral . fileSize <$> liftIO (getFileStatus tmp)
+		else return 0
+	ifM (checkDiskSpace Nothing key alreadythere)
+		( do
+			when e $ thawContent tmp
+			finishGetViaTmp check key action
+		, return False
+		)
+
+finishGetViaTmp :: Annex Bool -> Key -> (FilePath -> Annex Bool) -> Annex Bool
+finishGetViaTmp check key action = do
+	tmpfile <- prepTmp key
+	ifM (action tmpfile <&&> check)
+		( do
+			moveAnnex key tmpfile
+			logStatus key InfoPresent
+			return True
+		, do
+			-- the tmp file is left behind, in case caller wants
+			-- to resume its transfer
+			return False
+		)
+
+prepTmp :: Key -> Annex FilePath
+prepTmp key = do
+	tmp <- fromRepo $ gitAnnexTmpLocation key
+	createAnnexDirectory (parentDir tmp)
+	return tmp
+
+{- Creates a temp file, runs an action on it, and cleans up the temp file. -}
+withTmp :: Key -> (FilePath -> Annex a) -> Annex a
+withTmp key action = do
+	tmp <- prepTmp key
+	res <- action tmp
+	liftIO $ nukeFile tmp
+	return res
+
+{- Checks that there is disk space available to store a given key,
+ - in a destination (or the annex) printing a warning if not. -}
+checkDiskSpace :: Maybe FilePath -> Key -> Integer -> Annex Bool
+checkDiskSpace destination key alreadythere = do
+	reserve <- annexDiskReserve <$> Annex.getGitConfig
+	free <- liftIO . getDiskFree =<< dir
+	force <- Annex.getState Annex.force
+	case (free, keySize key) of
+		(Just have, Just need) -> do
+			let ok = (need + reserve <= have + alreadythere) || force
+			unless ok $
+				needmorespace (need + reserve - have - alreadythere)
+			return ok
+		_ -> return True
+  where
+	dir = maybe (fromRepo gitAnnexDir) return destination
+	needmorespace n =
+		warning $ "not enough free space, need " ++ 
+			roughSize storageUnits True n ++
+			" more" ++ forcemsg
+	forcemsg = " (use --force to override this check or adjust annex.diskreserve)"
+
+{- Moves a key's content into .git/annex/objects/
+ -
+ - In direct mode, moves it to the associated file, or files.
+ -
+ - What if the key there already has content? This could happen for
+ - various reasons; perhaps the same content is being annexed again.
+ - Perhaps there has been a hash collision generating the keys.
+ -
+ - The current strategy is to assume that in this case it's safe to delete
+ - one of the two copies of the content; and the one already in the annex
+ - is left there, assuming it's the original, canonical copy.
+ -
+ - I considered being more paranoid, and checking that both files had
+ - the same content. Decided against it because A) users explicitly choose
+ - a backend based on its hashing properties and so if they're dealing
+ - with colliding files it's their own fault and B) adding such a check
+ - would not catch all cases of colliding keys. For example, perhaps 
+ - a remote has a key; if it's then added again with different content then
+ - the overall system now has two different peices of content for that
+ - key, and one of them will probably get deleted later. So, adding the
+ - check here would only raise expectations that git-annex cannot truely
+ - meet.
+ -}
+moveAnnex :: Key -> FilePath -> Annex ()
+moveAnnex key src = withObjectLoc key storeobject storedirect
+  where
+	storeobject dest = ifM (liftIO $ doesFileExist dest)
+		( alreadyhave
+		, modifyContent dest $ do
+			liftIO $ moveFile src dest
+			freezeContent dest
+		)
+	storeindirect = storeobject =<< calcRepo (gitAnnexLocation key)
+
+	{- In direct mode, the associated file's content may be locally
+	 - modified. In that case, it's preserved. However, the content
+	 - we're moving into the annex may be the only extant copy, so
+	 - it's important we not lose it. So, when the key's content
+	 - cannot be moved to any associated file, it's stored in indirect
+	 - mode.
+	 -}
+	storedirect = storedirect' storeindirect
+	storedirect' fallback [] = fallback
+	storedirect' fallback (f:fs) = do
+		thawContent src
+		v <- isAnnexLink f
+		if Just key == v
+			then do
+				updateInodeCache key src
+				replaceFile f $ liftIO . moveFile src
+				chmodContent f
+				forM_ fs $
+					addContentWhenNotPresent key f
+			else ifM (goodContent key f)
+				( storedirect' alreadyhave fs
+				, storedirect' fallback fs
+				)
+	
+	alreadyhave = liftIO $ removeFile src
+
+{- Runs an action to transfer an object's content.
+ -
+ - In direct mode, it's possible for the file to change as it's being sent.
+ - If this happens, runs the rollback action and returns False. The
+ - rollback action should remove the data that was transferred.
+ -}
+sendAnnex :: Key -> Annex () -> (FilePath -> Annex Bool) -> Annex Bool
+sendAnnex key rollback sendobject = go =<< prepSendAnnex key
+  where
+	go Nothing = return False
+	go (Just (f, checksuccess)) = do
+		r <- sendobject f
+		ifM checksuccess
+			( return r
+			, do
+				rollback
+				return False
+			)
+
+{- Returns a file that contains an object's content,
+ - and an check to run after the transfer is complete.
+ -
+ - In direct mode, it's possible for the file to change as it's being sent,
+ - and the check detects this case and returns False.
+ -
+ - Note that the returned check action is, in some cases, run in the
+ - Annex monad of the remote that is receiving the object, rather than
+ - the sender. So it cannot rely on Annex state.
+ -}
+prepSendAnnex :: Key -> Annex (Maybe (FilePath, Annex Bool))
+prepSendAnnex key = withObjectLoc key indirect direct
+  where
+	indirect f = return $ Just (f, return True)
+	direct [] = return Nothing
+	direct (f:fs) = do
+		cache <- recordedInodeCache key
+		-- check that we have a good file
+		ifM (sameInodeCache f cache)
+			( return $ Just (f, sameInodeCache f cache)
+			, direct fs
+			)
+
+{- Performs an action, passing it the location to use for a key's content.
+ -
+ - In direct mode, the associated files will be passed. But, if there are
+ - no associated files for a key, the indirect mode action will be
+ - performed instead. -}
+withObjectLoc :: Key -> (FilePath -> Annex a) -> ([FilePath] -> Annex a) -> Annex a
+withObjectLoc key indirect direct = ifM isDirect
+	( do
+		fs <- associatedFiles key
+		if null fs
+			then goindirect
+			else direct fs
+	, goindirect
+	)
+  where
+	goindirect = indirect =<< calcRepo (gitAnnexLocation key)
+
+cleanObjectLoc :: Key -> Annex () -> Annex ()
+cleanObjectLoc key cleaner = do
+	file <- calcRepo $ gitAnnexLocation key
+	void $ tryAnnexIO $ thawContentDir file
+	cleaner
+	liftIO $ removeparents file (3 :: Int)
+  where
+	removeparents _ 0 = noop
+	removeparents file n = do
+		let dir = parentDir file
+		maybe noop (const $ removeparents dir (n-1))
+			<=< catchMaybeIO $ removeDirectory dir
+
+{- Removes a key's file from .git/annex/objects/
+ -
+ - In direct mode, deletes the associated files or files, and replaces
+ - them with symlinks. -}
+removeAnnex :: Key -> Annex ()
+removeAnnex key = withObjectLoc key remove removedirect
+  where
+	remove file = cleanObjectLoc key $ do
+		liftIO $ nukeFile file
+		removeInodeCache key
+	removedirect fs = do
+		cache <- recordedInodeCache key
+		removeInodeCache key
+		mapM_ (resetfile cache) fs
+	resetfile cache f = whenM (sameInodeCache f cache) $ do
+		l <- inRepo $ gitAnnexLink f key
+		top <- fromRepo Git.repoPath
+		cwd <- liftIO getCurrentDirectory
+		let top' = fromMaybe top $ absNormPath cwd top
+		let l' = relPathDirToFile top' (fromMaybe l $ absNormPath top' l)
+		replaceFile f $ makeAnnexLink l'
+
+{- Moves a key's file out of .git/annex/objects/ -}
+fromAnnex :: Key -> FilePath -> Annex ()
+fromAnnex key dest = cleanObjectLoc key $ do
+	file <- calcRepo $ gitAnnexLocation key
+	thawContent file
+	liftIO $ moveFile file dest
+
+{- Moves a key out of .git/annex/objects/ into .git/annex/bad, and
+ - returns the file it was moved to. -}
+moveBad :: Key -> Annex FilePath
+moveBad key = do
+	src <- calcRepo $ gitAnnexLocation key
+	bad <- fromRepo gitAnnexBadDir
+	let dest = bad </> takeFileName src
+	createAnnexDirectory (parentDir dest)
+	cleanObjectLoc key $
+		liftIO $ moveFile src dest
+	logStatus key InfoMissing
+	return dest
+
+{- List of keys whose content exists in the annex. -}
+getKeysPresent :: Annex [Key]
+getKeysPresent = do
+	direct <- isDirect
+	dir <- fromRepo gitAnnexObjectDir
+	liftIO $ traverse direct (2 :: Int) dir
+  where
+	traverse direct depth dir = do
+		contents <- catchDefaultIO [] (dirContents dir)
+		if depth == 0
+			then do
+				contents' <- filterM (present direct) contents
+				let keys = mapMaybe (fileKey . takeFileName) contents'
+				continue keys []
+			else do
+				let deeper = traverse direct (depth - 1)
+				continue [] (map deeper contents)
+	continue keys [] = return keys
+	continue keys (a:as) = do
+		{- Force lazy traversal with unsafeInterleaveIO. -}
+		morekeys <- unsafeInterleaveIO a
+		continue (morekeys++keys) as
+
+	{- In indirect mode, look for the key. In direct mode,
+	 - the inode cache file is only present when a key's content
+	 - is present. -}
+	present False d = doesFileExist $ contentfile d
+	present True d = doesFileExist $ contentfile d ++ ".cache"
+	contentfile d = d </> takeFileName d
+
+{- Things to do to record changes to content when shutting down.
+ -
+ - It's acceptable to avoid committing changes to the branch,
+ - especially if performing a short-lived action.
+ -}
+saveState :: Bool -> Annex ()
+saveState nocommit = doSideAction $ do
+	Annex.Queue.flush
+	unless nocommit $
+		whenM (annexAlwaysCommit <$> Annex.getGitConfig) $
+			Annex.Branch.commit "update"
+
+{- Downloads content from any of a list of urls. -}
+downloadUrl :: [Url.URLString] -> FilePath -> Annex Bool
+downloadUrl urls file = go =<< annexWebDownloadCommand <$> Annex.getGitConfig
+  where
+  	go Nothing = do
+		opts <- map Param . annexWebOptions <$> Annex.getGitConfig
+		headers <- getHttpHeaders
+		anyM (\u -> Url.withUserAgent $ Url.download u headers opts file) urls
+	go (Just basecmd) = liftIO $ anyM (downloadcmd basecmd) urls
+	downloadcmd basecmd url =
+		boolSystem "sh" [Param "-c", Param $ gencmd url basecmd]
+			<&&> doesFileExist file
+	gencmd url = massReplace
+		[ ("%file", shellEscape file)
+		, ("%url", shellEscape url)
+		]
+
+{- Copies a key's content, when present, to a temp file.
+ - This is used to speed up some rsyncs. -}
+preseedTmp :: Key -> FilePath -> Annex Bool
+preseedTmp key file = go =<< inAnnex key
+  where
+	go False = return False
+	go True = do
+		ok <- copy
+		when ok $ thawContent file
+		return ok
+	copy = ifM (liftIO $ doesFileExist file)
+		( return True
+		, do
+			s <- calcRepo $ gitAnnexLocation key
+			liftIO $ copyFileExternal s file
+		)
+
+{- Blocks writing to an annexed file, and modifies file permissions to
+ - allow reading it, per core.sharedRepository setting. -}
+freezeContent :: FilePath -> Annex ()
+freezeContent file = unlessM crippledFileSystem $
+	liftIO . go =<< fromRepo getSharedRepository
+  where
+	go GroupShared = modifyFileMode file $
+		removeModes writeModes .
+		addModes [ownerReadMode, groupReadMode]
+	go AllShared = modifyFileMode file $
+		removeModes writeModes .
+		addModes readModes
+	go _ = modifyFileMode file $
+		removeModes writeModes .
+		addModes [ownerReadMode]
+
+{- Adjusts read mode of annexed file per core.sharedRepository setting. -}
+chmodContent :: FilePath -> Annex ()
+chmodContent file = unlessM crippledFileSystem $
+	liftIO . go =<< fromRepo getSharedRepository
+  where
+	go GroupShared = modifyFileMode file $
+		addModes [ownerReadMode, groupReadMode]
+	go AllShared = modifyFileMode file $
+		addModes readModes
+	go _ = modifyFileMode file $
+		addModes [ownerReadMode]
+
+{- Allows writing to an annexed file that freezeContent was called on
+ - before. -}
+thawContent :: FilePath -> Annex ()
+thawContent file = unlessM crippledFileSystem $
+	liftIO . go =<< fromRepo getSharedRepository
+  where
+	go GroupShared = groupWriteRead file
+	go AllShared = groupWriteRead file
+	go _ = allowWrite file
+
+{- Finds files directly inside a directory like gitAnnexBadDir 
+ - (not in subdirectories) and returns the corresponding keys. -}
+dirKeys :: (Git.Repo -> FilePath) -> Annex [Key]
+dirKeys dirspec = do
+	dir <- fromRepo dirspec
+	ifM (liftIO $ doesDirectoryExist dir)
+		( do
+			contents <- liftIO $ getDirectoryContents dir
+			files <- liftIO $ filterM doesFileExist $
+				map (dir </>) contents
+			return $ mapMaybe (fileKey . takeFileName) files
+		, return []
+		)
+
diff --git a/Annex/Content/Direct.hs b/Annex/Content/Direct.hs
new file mode 100644
index 000000000..a5d71288b
--- /dev/null
+++ b/Annex/Content/Direct.hs
@@ -0,0 +1,259 @@
+{- git-annex file content managing for direct mode
+ -
+ - Copyright 2012-2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Content.Direct (
+	associatedFiles,
+	associatedFilesRelative,
+	removeAssociatedFile,
+	removeAssociatedFileUnchecked,
+	removeAssociatedFiles,
+	addAssociatedFile,
+	goodContent,
+	recordedInodeCache,
+	updateInodeCache,
+	addInodeCache,
+	writeInodeCache,
+	compareInodeCaches,
+	compareInodeCachesWith,
+	sameInodeCache,
+	elemInodeCaches,
+	sameFileStatus,
+	removeInodeCache,
+	toInodeCache,
+	inodesChanged,
+	createInodeSentinalFile,
+	addContentWhenNotPresent,
+) where
+
+import Common.Annex
+import qualified Annex
+import Annex.Perms
+import qualified Git
+import Utility.Tmp
+import Logs.Location
+import Utility.InodeCache
+import Utility.CopyFile
+import Annex.ReplaceFile
+import Annex.Link
+
+{- Absolute FilePaths of Files in the tree that are associated with a key. -}
+associatedFiles :: Key -> Annex [FilePath]
+associatedFiles key = do
+	files <- associatedFilesRelative key
+	top <- fromRepo Git.repoPath
+	return $ map (top </>) files
+
+{- List of files in the tree that are associated with a key, relative to
+ - the top of the repo. -}
+associatedFilesRelative :: Key -> Annex [FilePath] 
+associatedFilesRelative key = do
+	mapping <- calcRepo $ gitAnnexMapping key
+	liftIO $ catchDefaultIO [] $ do
+		h <- openFile mapping ReadMode
+		fileEncoding h
+		lines <$> hGetContents h
+
+{- Changes the associated files information for a key, applying a
+ - transformation to the list. Returns new associatedFiles value. -}
+changeAssociatedFiles :: Key -> ([FilePath] -> [FilePath]) -> Annex [FilePath]
+changeAssociatedFiles key transform = do
+	mapping <- calcRepo $ gitAnnexMapping key
+	files <- associatedFilesRelative key
+	let files' = transform files
+	when (files /= files') $ do
+		modifyContent mapping $
+			liftIO $ viaTmp write mapping $ unlines files'
+	top <- fromRepo Git.repoPath
+	return $ map (top </>) files'
+  where
+	write file content = do
+		h <- openFile file WriteMode
+		fileEncoding h
+ 		hPutStr h content
+		hClose h
+
+{- Removes the list of associated files. -}
+removeAssociatedFiles :: Key -> Annex ()
+removeAssociatedFiles key = do
+	mapping <- calcRepo $ gitAnnexMapping key
+	modifyContent mapping $
+		liftIO $ nukeFile mapping
+
+{- Removes an associated file. Returns new associatedFiles value.
+ - Checks if this was the last copy of the object, and updates location
+ - log. -}
+removeAssociatedFile :: Key -> FilePath -> Annex [FilePath]
+removeAssociatedFile key file = do
+	fs <- removeAssociatedFileUnchecked key file
+	when (null fs) $
+		logStatus key InfoMissing
+	return fs
+
+{- Removes an associated file. Returns new associatedFiles value. -}
+removeAssociatedFileUnchecked :: Key -> FilePath -> Annex [FilePath]
+removeAssociatedFileUnchecked key file = do
+	file' <- normaliseAssociatedFile file
+	changeAssociatedFiles key $ filter (/= file')
+
+{- Adds an associated file. Returns new associatedFiles value. -}
+addAssociatedFile :: Key -> FilePath -> Annex [FilePath]
+addAssociatedFile key file = do
+	file' <- normaliseAssociatedFile file
+	changeAssociatedFiles key $ \files ->
+		if file' `elem` files
+			then files
+			else file':files
+
+{- Associated files are always stored relative to the top of the repository.
+ - The input FilePath is relative to the CWD, or is absolute. -}
+normaliseAssociatedFile :: FilePath -> Annex FilePath
+normaliseAssociatedFile file = do
+	top <- fromRepo Git.repoPath
+	liftIO $ relPathDirToFile top <$> absPath file
+
+{- Checks if a file in the tree, associated with a key, has not been modified.
+ -
+ - To avoid needing to fsck the file's content, which can involve an
+ - expensive checksum, this relies on a cache that contains the file's
+ - expected mtime and inode.
+ -}
+goodContent :: Key -> FilePath -> Annex Bool
+goodContent key file = sameInodeCache file =<< recordedInodeCache key
+
+{- Gets the recorded inode cache for a key. 
+ -
+ - A key can be associated with multiple files, so may return more than
+ - one. -}
+recordedInodeCache :: Key -> Annex [InodeCache]
+recordedInodeCache key = withInodeCacheFile key $ \f ->
+	liftIO $ catchDefaultIO [] $
+		mapMaybe readInodeCache . lines <$> readFileStrict f
+
+{- Caches an inode for a file.
+ -
+ - Anything else already cached is preserved.
+ -}
+updateInodeCache :: Key -> FilePath -> Annex ()
+updateInodeCache key file = maybe noop (addInodeCache key)
+	=<< liftIO (genInodeCache file)
+
+{- Adds another inode to the cache for a key. -}
+addInodeCache :: Key -> InodeCache -> Annex ()
+addInodeCache key cache = do
+	oldcaches <- recordedInodeCache key
+	unlessM (elemInodeCaches cache oldcaches) $
+		writeInodeCache key (cache:oldcaches)
+
+{- Writes inode cache for a key. -}
+writeInodeCache :: Key -> [InodeCache] -> Annex ()
+writeInodeCache key caches = withInodeCacheFile key $ \f -> 
+	modifyContent f $
+		liftIO $ writeFile f $
+			unlines $ map showInodeCache caches
+
+{- Removes an inode cache. -}
+removeInodeCache :: Key -> Annex ()
+removeInodeCache key = withInodeCacheFile key $ \f ->
+	modifyContent f $
+		liftIO $ nukeFile f
+
+withInodeCacheFile :: Key -> (FilePath -> Annex a) -> Annex a
+withInodeCacheFile key a = a =<< calcRepo (gitAnnexInodeCache key)
+
+{- Checks if a InodeCache matches the current version of a file. -}
+sameInodeCache :: FilePath -> [InodeCache] -> Annex Bool
+sameInodeCache _ [] = return False
+sameInodeCache file old = go =<< liftIO (genInodeCache file)
+  where
+	go Nothing = return False
+	go (Just curr) = elemInodeCaches curr old
+
+{- Checks if a FileStatus matches the recorded InodeCache of a file. -}
+sameFileStatus :: Key -> FileStatus -> Annex Bool
+sameFileStatus key status = do
+	old <- recordedInodeCache key
+	let curr = toInodeCache status
+	case (old, curr) of
+		(_, Just c) -> elemInodeCaches c old
+		([], Nothing) -> return True
+		_ -> return False
+
+{- If the inodes have changed, only the size and mtime are compared. -}
+compareInodeCaches :: InodeCache -> InodeCache -> Annex Bool
+compareInodeCaches x y
+	| compareStrong x y = return True
+	| otherwise = ifM inodesChanged
+		( return $ compareWeak x y
+		, return False
+		)
+
+elemInodeCaches :: InodeCache -> [InodeCache] -> Annex Bool
+elemInodeCaches _ [] = return False
+elemInodeCaches c (l:ls) = ifM (compareInodeCaches c l)
+	( return True
+	, elemInodeCaches c ls
+	)
+
+compareInodeCachesWith :: Annex InodeComparisonType
+compareInodeCachesWith = ifM inodesChanged ( return Weakly, return Strongly )
+
+{- Copies the contentfile to the associated file, if the associated
+ - file has no content. If the associated file does have content,
+ - even if the content differs, it's left unchanged. -}
+addContentWhenNotPresent :: Key -> FilePath -> FilePath -> Annex ()
+addContentWhenNotPresent key contentfile associatedfile = do
+	v <- isAnnexLink associatedfile
+	when (Just key == v) $
+		replaceFile associatedfile $
+			liftIO . void . copyFileExternal contentfile
+	updateInodeCache key associatedfile	
+
+{- Some filesystems get new inodes each time they are mounted.
+ - In order to work on such a filesystem, a sentinal file is used to detect
+ - when the inodes have changed.
+ -
+ - If the sentinal file does not exist, we have to assume that the
+ - inodes have changed.
+ -}
+inodesChanged :: Annex Bool
+inodesChanged = maybe calc return =<< Annex.getState Annex.inodeschanged
+  where
+	calc = do
+		scache <- liftIO . genInodeCache
+			=<< fromRepo gitAnnexInodeSentinal
+		scached <- readInodeSentinalFile
+		let changed = case (scache, scached) of
+			(Just c1, Just c2) -> not $ compareStrong c1 c2
+			_ -> True
+		Annex.changeState $ \s -> s { Annex.inodeschanged = Just changed }
+		return changed
+
+readInodeSentinalFile :: Annex (Maybe InodeCache)
+readInodeSentinalFile = do
+	sentinalcachefile <- fromRepo gitAnnexInodeSentinalCache
+	liftIO $ catchDefaultIO Nothing $
+		readInodeCache <$> readFile sentinalcachefile
+
+writeInodeSentinalFile :: Annex ()
+writeInodeSentinalFile = do
+	sentinalfile <- fromRepo gitAnnexInodeSentinal
+	createAnnexDirectory (parentDir sentinalfile)
+	sentinalcachefile <- fromRepo gitAnnexInodeSentinalCache
+	liftIO $ writeFile sentinalfile ""
+	liftIO $ maybe noop (writeFile sentinalcachefile . showInodeCache)
+		=<< genInodeCache sentinalfile
+
+{- The sentinal file is only created when first initializing a repository.
+ - If there are any annexed objects in the repository already, creating
+ - the file would invalidate their inode caches. -}
+createInodeSentinalFile :: Annex ()
+createInodeSentinalFile =
+	unlessM (alreadyexists <||> hasobjects)
+		writeInodeSentinalFile
+  where
+	alreadyexists = isJust <$> readInodeSentinalFile
+	hasobjects = liftIO . doesDirectoryExist =<< fromRepo gitAnnexObjectDir
diff --git a/Annex/Direct.hs b/Annex/Direct.hs
new file mode 100644
index 000000000..3fa5f9362
--- /dev/null
+++ b/Annex/Direct.hs
@@ -0,0 +1,306 @@
+{- git-annex direct mode
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Direct where
+
+import Common.Annex
+import qualified Annex
+import qualified Git
+import qualified Git.LsFiles
+import qualified Git.Merge
+import qualified Git.DiffTree as DiffTree
+import qualified Git.Config
+import qualified Git.Ref
+import qualified Git.Branch
+import Git.Sha
+import Git.FilePath
+import Git.Types
+import Config
+import Annex.CatFile
+import qualified Annex.Queue
+import Logs.Location
+import Backend
+import Types.KeySource
+import Annex.Content
+import Annex.Content.Direct
+import Annex.Link
+import Utility.InodeCache
+import Utility.CopyFile
+import Annex.Perms
+import Annex.ReplaceFile
+import Annex.Exception
+
+{- Uses git ls-files to find files that need to be committed, and stages
+ - them into the index. Returns True if some changes were staged. -}
+stageDirect :: Annex Bool
+stageDirect = do
+	Annex.Queue.flush
+	top <- fromRepo Git.repoPath
+	(l, cleanup) <- inRepo $ Git.LsFiles.stagedOthersDetails [top]
+	forM_ l go
+	void $ liftIO cleanup
+	staged <- Annex.Queue.size
+	Annex.Queue.flush
+	return $ staged /= 0
+  where
+	{- Determine what kind of modified or deleted file this is, as
+	 - efficiently as we can, by getting any key that's associated
+	 - with it in git, as well as its stat info. -}
+	go (file, Just sha, Just mode) = do
+		shakey <- catKey sha mode
+		mstat <- liftIO $ catchMaybeIO $ getSymbolicLinkStatus file
+		filekey <- isAnnexLink file
+		case (shakey, filekey, mstat, toInodeCache =<< mstat) of
+			(_, Just key, _, _)
+				| shakey == filekey -> noop
+				{- A changed symlink. -}
+				| otherwise -> stageannexlink file key
+			(Just key, _, _, Just cache) -> do
+				{- All direct mode files will show as
+				 - modified, so compare the cache to see if
+				 - it really was. -}
+				oldcache <- recordedInodeCache key
+				case oldcache of
+					[] -> modifiedannexed file key cache
+					_ -> unlessM (elemInodeCaches cache oldcache) $
+						modifiedannexed file key cache
+			(Just key, _, Nothing, _) -> deletedannexed file key
+			(Nothing, _, Nothing, _) -> deletegit file
+			(_, _, Just _, _) -> addgit file
+	go _ = noop
+
+	modifiedannexed file oldkey cache = do
+		void $ removeAssociatedFile oldkey file
+		void $ addDirect file cache
+	
+	deletedannexed file key = do
+		void $ removeAssociatedFile key file
+		deletegit file
+	
+	stageannexlink file key = do
+		l <- inRepo $ gitAnnexLink file key
+		stageSymlink file =<< hashSymlink l
+		void $ addAssociatedFile key file
+
+	addgit file = Annex.Queue.addCommand "add" [Param "-f"] [file]
+
+	deletegit file = Annex.Queue.addCommand "rm" [Param "-f"] [file]
+
+{- Adds a file to the annex in direct mode. Can fail, if the file is
+ - modified or deleted while it's being added. -}
+addDirect :: FilePath -> InodeCache -> Annex Bool
+addDirect file cache = do
+	showStart "add" file
+	let source = KeySource
+		{ keyFilename = file
+		, contentLocation = file
+		, inodeCache = Just cache
+		}
+	got =<< genKey source =<< chooseBackend file
+  where
+	got Nothing = do
+		showEndFail
+		return False
+	got (Just (key, _)) = ifM (sameInodeCache file [cache])
+		( do
+			l <- inRepo $ gitAnnexLink file key
+			stageSymlink file =<< hashSymlink l
+			addInodeCache key cache
+			void $ addAssociatedFile key file
+			logStatus key InfoPresent
+			showEndOk
+			return True
+		, do
+			showEndFail
+			return False
+		)
+
+{- In direct mode, git merge would usually refuse to do anything, since it
+ - sees present direct mode files as type changed files. To avoid this,
+ - merge is run with the work tree set to a temp directory.
+ -
+ - This should only be used once any changes to the real working tree have
+ - already been committed, because it overwrites files in the working tree.
+ -}
+mergeDirect :: FilePath -> Git.Ref -> Git.Repo -> IO Bool
+mergeDirect d branch g = do
+	whenM (doesDirectoryExist d) $
+		removeDirectoryRecursive d
+	createDirectoryIfMissing True d
+	let g' = g { location = Local { gitdir = Git.localGitDir g, worktree = Just d } }
+	Git.Merge.mergeNonInteractive branch g'
+
+{- Cleans up after a direct mode merge. The merge must have been committed,
+ - and the commit sha passed in, along with the old sha of the tree
+ - before the merge. Uses git diff-tree to find files that changed between
+ - the two shas, and applies those changes to the work tree.
+ -
+ - There are really only two types of changes: An old item can be deleted,
+ - or a new item added. Two passes are made, first deleting and then
+ - adding. This is to handle cases where eg, a file is deleted and a
+ - directory is added. The diff-tree output may list these in the opposite
+ - order, but we cannot really add the directory until the file with the
+ - same name is remvoed.
+ -}
+mergeDirectCleanup :: FilePath -> Git.Ref -> Git.Ref -> Annex ()
+mergeDirectCleanup d oldsha newsha = do
+	(items, cleanup) <- inRepo $ DiffTree.diffTreeRecursive oldsha newsha
+	makeabs <- flip fromTopFilePath <$> gitRepo
+	let fsitems = zip (map (makeabs . DiffTree.file) items) items
+	forM_ fsitems $
+		go DiffTree.srcsha DiffTree.srcmode moveout moveout_raw
+	forM_ fsitems $
+		go DiffTree.dstsha DiffTree.dstmode movein movein_raw
+	void $ liftIO cleanup
+	liftIO $ removeDirectoryRecursive d
+  where
+	go getsha getmode a araw (f, item)
+		| getsha item == nullSha = noop
+		| otherwise = void $
+			tryAnnex . maybe (araw f) (\k -> void $ a k f)
+				=<< catKey (getsha item) (getmode item)
+
+	moveout k f = removeDirect k f
+
+	{- Files deleted by the merge are removed from the work tree.
+	 - Empty work tree directories are removed, per git behavior. -}
+	moveout_raw f = liftIO $ do
+		nukeFile f
+		void $ tryIO $ removeDirectory $ parentDir f
+	
+	{- If the file is already present, with the right content for the
+	 - key, it's left alone. Otherwise, create the symlink and then
+	 - if possible, replace it with the content. -}
+	movein k f = unlessM (goodContent k f) $ do
+		l <- inRepo $ gitAnnexLink f k
+		replaceFile f $ makeAnnexLink l
+		toDirect k f
+	
+	{- Any new, modified, or renamed files were written to the temp
+	 - directory by the merge, and are moved to the real work tree. -}
+	movein_raw f = liftIO $ do
+		createDirectoryIfMissing True $ parentDir f
+		void $ tryIO $ rename (d </> f) f
+
+{- If possible, converts a symlink in the working tree into a direct
+ - mode file. If the content is not available, leaves the symlink
+ - unchanged. -}
+toDirect :: Key -> FilePath -> Annex ()
+toDirect k f = fromMaybe noop =<< toDirectGen k f
+
+toDirectGen :: Key -> FilePath -> Annex (Maybe (Annex ()))
+toDirectGen k f = do
+	loc <- calcRepo $ gitAnnexLocation k
+	ifM (liftIO $ doesFileExist loc)
+		( return $ Just $ fromindirect loc
+		, do
+			{- Copy content from another direct file. -}
+			absf <- liftIO $ absPath f
+			dlocs <- filterM (goodContent k) =<<
+				filterM (\l -> isNothing <$> getAnnexLinkTarget l) =<<
+				(filter (/= absf) <$> addAssociatedFile k f)
+			case dlocs of
+				[] -> return Nothing
+				(dloc:_) -> return $ Just $ fromdirect dloc
+		)
+  where
+  	fromindirect loc = do
+		{- Move content from annex to direct file. -}
+		updateInodeCache k loc
+		void $ addAssociatedFile k f
+		modifyContent loc $ do
+			thawContent loc
+			replaceFile f $ liftIO . moveFile loc
+	fromdirect loc = do
+		replaceFile f $
+			liftIO . void . copyFileExternal loc
+		updateInodeCache k f
+
+{- Removes a direct mode file, while retaining its content in the annex
+ - (unless its content has already been changed). -}
+removeDirect :: Key -> FilePath -> Annex ()
+removeDirect k f = do
+	void $ removeAssociatedFileUnchecked k f
+	unlessM (inAnnex k) $
+		ifM (goodContent k f)
+			( moveAnnex k f
+			, logStatus k InfoMissing
+			)
+	liftIO $ do
+		nukeFile f
+		void $ tryIO $ removeDirectory $ parentDir f
+
+{- Called when a direct mode file has been changed. Its old content may be
+ - lost. -}
+changedDirect :: Key -> FilePath -> Annex ()
+changedDirect oldk f = do
+	locs <- removeAssociatedFile oldk f
+	whenM (pure (null locs) <&&> not <$> inAnnex oldk) $
+		logStatus oldk InfoMissing
+
+{- Enable/disable direct mode. -}
+setDirect :: Bool -> Annex ()
+setDirect wantdirect = do
+	if wantdirect
+		then do
+			switchHEAD
+			setbare
+		else do
+			setbare
+			switchHEADBack
+	setConfig (annexConfig "direct") val
+	Annex.changeGitConfig $ \c -> c { annexDirect = wantdirect }
+  where
+	val = Git.Config.boolConfig wantdirect
+	setbare = setConfig (ConfigKey Git.Config.coreBare) val
+
+{- Since direct mode sets core.bare=true, incoming pushes could change
+ - the currently checked out branch. To avoid this problem, HEAD
+ - is changed to a internal ref that nothing is going to push to.
+ -
+ - For refs/heads/master, use refs/heads/annex/direct/master;
+ - this way things that show HEAD (eg shell prompts) will
+ - hopefully show just "master". -}
+directBranch :: Ref -> Ref
+directBranch orighead = case split "/" $ show orighead of
+	("refs":"heads":"annex":"direct":_) -> orighead
+	("refs":"heads":rest) ->
+		Ref $ "refs/heads/annex/direct/" ++ intercalate "/" rest
+	_ -> Ref $ "refs/heads/" ++ show (Git.Ref.base orighead)
+
+{- Converts a directBranch back to the original branch.
+ -
+ - Any other ref is left unchanged.
+ -}
+fromDirectBranch :: Ref -> Ref
+fromDirectBranch directhead = case split "/" $ show directhead of
+	("refs":"heads":"annex":"direct":rest) -> 
+		Ref $ "refs/heads/" ++ intercalate "/" rest
+	_ -> directhead
+
+switchHEAD :: Annex ()
+switchHEAD = maybe noop switch =<< inRepo Git.Branch.currentUnsafe
+  where
+	switch orighead = do
+		let newhead = directBranch orighead
+		maybe noop (inRepo . Git.Branch.update newhead)
+			=<< inRepo (Git.Ref.sha orighead)
+		inRepo $ Git.Branch.checkout newhead
+
+switchHEADBack :: Annex ()
+switchHEADBack = maybe noop switch =<< inRepo Git.Branch.currentUnsafe
+  where
+	switch currhead = do
+		let orighead = fromDirectBranch currhead
+		v <- inRepo $ Git.Ref.sha currhead
+		case v of
+			Just headsha
+				| orighead /= currhead -> do
+					inRepo $ Git.Branch.update orighead headsha
+					inRepo $ Git.Branch.checkout orighead
+					inRepo $ Git.Branch.delete currhead
+			_ -> inRepo $ Git.Branch.checkout orighead
diff --git a/Annex/Direct/Fixup.hs b/Annex/Direct/Fixup.hs
new file mode 100644
index 000000000..13485242a
--- /dev/null
+++ b/Annex/Direct/Fixup.hs
@@ -0,0 +1,31 @@
+{- git-annex direct mode guard fixup
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Direct.Fixup where
+
+import Git.Types
+import Git.Config
+import qualified Git.Construct as Construct
+import Utility.Path
+import Utility.SafeCommand
+
+{- Direct mode repos have core.bare=true, but are not really bare.
+ - Fix up the Repo to be a non-bare repo, and arrange for git commands
+ - run by git-annex to be passed parameters that override this setting. -}
+fixupDirect :: Repo -> IO Repo
+fixupDirect r@(Repo { location = l@(Local { gitdir = d, worktree = Nothing }) }) = do
+	let r' = r
+		{ location = l { worktree = Just (parentDir d) }
+		, gitGlobalOpts = gitGlobalOpts r ++
+			[ Param "-c"
+			, Param $ coreBare ++ "=" ++ boolConfig False
+			]
+		}
+	-- Recalc now that the worktree is correct.
+	rs' <- Construct.fromRemotes r'
+	return $ r' { remotes = rs' }
+fixupDirect r = return r
diff --git a/Annex/Environment.hs b/Annex/Environment.hs
new file mode 100644
index 000000000..f22c5f2d4
--- /dev/null
+++ b/Annex/Environment.hs
@@ -0,0 +1,65 @@
+{- git-annex environment
+ -
+ - Copyright 2012, 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Annex.Environment where
+
+import Common.Annex
+import Utility.UserInfo
+import qualified Git.Config
+import Config
+import Annex.Exception
+
+#ifndef mingw32_HOST_OS
+import Utility.Env
+#endif
+
+{- Checks that the system's environment allows git to function.
+ - Git requires a GECOS username, or suitable git configuration, or
+ - environment variables.
+ -
+ - Git also requires the system have a hostname containing a dot.
+ - Otherwise, it tries various methods to find a FQDN, and will fail if it
+ - does not. To avoid replicating that code here, which would break if its
+ - methods change, this function does not check the hostname is valid.
+ - Instead, code that commits can use ensureCommit.
+ -}
+checkEnvironment :: Annex ()
+checkEnvironment = do
+	gitusername <- fromRepo $ Git.Config.getMaybe "user.name"
+	when (isNothing gitusername || gitusername == Just "") $
+		liftIO checkEnvironmentIO
+
+checkEnvironmentIO :: IO ()
+checkEnvironmentIO =
+#ifdef mingw32_HOST_OS
+	noop
+#else
+	whenM (null <$> myUserGecos) $ do
+		username <- myUserName
+		ensureEnv "GIT_AUTHOR_NAME" username
+		ensureEnv "GIT_COMMITTER_NAME" username
+  where
+#ifndef __ANDROID__
+  	-- existing environment is not overwritten
+	ensureEnv var val = void $ setEnv var val False
+#else
+	-- Environment setting is broken on Android, so this is dealt with
+	-- in runshell instead.
+	ensureEnv _ _ = noop
+#endif
+#endif
+
+{- Runs an action that commits to the repository, and if it fails, 
+ - sets user.email to a dummy value and tries the action again. -}
+ensureCommit :: Annex a -> Annex a
+ensureCommit a = either retry return =<< tryAnnex a 
+  where
+  	retry _ = do
+		setConfig (ConfigKey "user.email") =<< liftIO myUserName
+		a
diff --git a/Annex/Exception.hs b/Annex/Exception.hs
new file mode 100644
index 000000000..91347583e
--- /dev/null
+++ b/Annex/Exception.hs
@@ -0,0 +1,46 @@
+{- exception handling in the git-annex monad
+ -
+ - Note that when an Annex action fails and the exception is handled
+ - by these functions, any changes the action has made to the
+ - AnnexState are retained. This works because the Annex monad
+ - internally stores the AnnexState in a MVar.
+ -
+ - Copyright 2011-2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE PackageImports #-}
+
+module Annex.Exception (
+	bracketIO,
+	tryAnnex,
+	tryAnnexIO,
+	throwAnnex,
+	catchAnnex,
+) where
+
+import qualified "MonadCatchIO-transformers" Control.Monad.CatchIO as M
+import Control.Exception
+
+import Common.Annex
+
+{- Runs an Annex action, with setup and cleanup both in the IO monad. -}
+bracketIO :: IO v -> (v -> IO b) -> (v -> Annex a) -> Annex a
+bracketIO setup cleanup = M.bracket (liftIO setup) (liftIO . cleanup)
+
+{- try in the Annex monad -}
+tryAnnex :: Annex a -> Annex (Either SomeException a)
+tryAnnex = M.try
+
+{- try in the Annex monad, but only catching IO exceptions -}
+tryAnnexIO :: Annex a -> Annex (Either IOException a)
+tryAnnexIO = M.try
+
+{- throw in the Annex monad -}
+throwAnnex :: Exception e => e -> Annex a
+throwAnnex = M.throw
+
+{- catch in the Annex monad -}
+catchAnnex :: Exception e => Annex a -> (e -> Annex a) -> Annex a
+catchAnnex = M.catch
diff --git a/Annex/FileMatcher.hs b/Annex/FileMatcher.hs
new file mode 100644
index 000000000..cded857a2
--- /dev/null
+++ b/Annex/FileMatcher.hs
@@ -0,0 +1,102 @@
+{- git-annex file matching
+ -
+ - Copyright 2012, 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.FileMatcher where
+
+import qualified Data.Map as M
+
+import Common.Annex
+import Limit
+import Utility.Matcher
+import Types.Group
+import Types.Limit
+import Logs.Group
+import Logs.Remote
+import Annex.UUID
+import qualified Annex
+import Types.FileMatcher
+import Git.FilePath
+import Types.Remote (RemoteConfig)
+
+import Data.Either
+import qualified Data.Set as S
+
+type FileMatcher = Matcher MatchFiles
+
+checkFileMatcher :: FileMatcher -> FilePath -> Annex Bool
+checkFileMatcher matcher file = checkFileMatcher' matcher file S.empty True
+
+checkFileMatcher' :: FileMatcher -> FilePath -> AssumeNotPresent -> Bool -> Annex Bool
+checkFileMatcher' matcher file notpresent def
+	| isEmpty matcher = return def
+	| otherwise = do
+		matchfile <- getTopFilePath <$> inRepo (toTopFilePath file)
+		let fi = FileInfo
+			{ matchFile = matchfile
+			, relFile = file
+			}
+		matchMrun matcher $ \a -> a notpresent fi
+
+matchAll :: FileMatcher
+matchAll = generate []
+
+parsedToMatcher :: [Either String (Token MatchFiles)] -> Either String FileMatcher
+parsedToMatcher parsed = case partitionEithers parsed of
+	([], vs) -> Right $ generate vs
+	(es, _) -> Left $ unwords $ map ("Parse failure: " ++) es
+
+exprParser :: GroupMap -> M.Map UUID RemoteConfig -> Maybe UUID -> String -> [Either String (Token MatchFiles)]
+exprParser groupmap configmap mu expr =
+	map parse $ tokenizeMatcher expr
+  where
+	parse = parseToken 
+		(limitPresent mu)
+		(limitInDir preferreddir)
+		groupmap
+	preferreddir = fromMaybe "public" $
+		M.lookup "preferreddir" =<< (`M.lookup` configmap) =<< mu
+
+parseToken :: MkLimit -> MkLimit -> GroupMap -> String -> Either String (Token MatchFiles)
+parseToken checkpresent checkpreferreddir groupmap t
+	| t `elem` tokens = Right $ token t
+	| t == "present" = use checkpresent
+	| t == "inpreferreddir" = use checkpreferreddir
+	| otherwise = maybe (Left $ "near " ++ show t) use $ M.lookup k $
+		M.fromList
+			[ ("include", limitInclude)
+			, ("exclude", limitExclude)
+			, ("copies", limitCopies)
+			, ("inbackend", limitInBackend)
+			, ("largerthan", limitSize (>))
+			, ("smallerthan", limitSize (<))
+			, ("inallgroup", limitInAllGroup groupmap)
+			]
+  where
+	(k, v) = separate (== '=') t
+	use a = Operation <$> a v
+
+{- This is really dumb tokenization; there's no support for quoted values.
+ - Open and close parens are always treated as standalone tokens;
+ - otherwise tokens must be separated by whitespace. -}
+tokenizeMatcher :: String -> [String]
+tokenizeMatcher = filter (not . null ) . concatMap splitparens . words
+  where
+	splitparens = segmentDelim (`elem` "()")
+
+{- Generates a matcher for files large enough (or meeting other criteria)
+ - to be added to the annex, rather than directly to git. -}
+largeFilesMatcher :: Annex FileMatcher
+largeFilesMatcher = go =<< annexLargeFiles <$> Annex.getGitConfig
+  where
+  	go Nothing = return matchAll
+	go (Just expr) = do
+		gm <- groupMap
+		rc <- readRemoteLog
+		u <- getUUID
+		either badexpr return $
+			parsedToMatcher $ exprParser gm rc (Just u) expr
+	badexpr e = error $ "bad annex.largefiles configuration: " ++ e
diff --git a/Annex/Hook.hs b/Annex/Hook.hs
new file mode 100644
index 000000000..7301a0958
--- /dev/null
+++ b/Annex/Hook.hs
@@ -0,0 +1,42 @@
+{- git-annex git hooks
+ -
+ - Note that it's important that the scripts not change, otherwise
+ - removing old hooks using an old version of the script would fail.
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Hook where
+
+import Common.Annex
+import qualified Git.Hook as Git
+import Utility.Shell
+import Config
+
+preCommitHook :: Git.Hook
+preCommitHook = Git.Hook "pre-commit" (mkHookScript "git annex pre-commit .")
+
+mkHookScript :: String -> String
+mkHookScript s = unlines
+	[ shebang_local
+	, "# automatically configured by git-annex"
+	, s
+	]
+
+hookWrite :: Git.Hook -> Annex ()
+hookWrite h = 
+	-- cannot have git hooks in a crippled filesystem (no execute bit)
+	unlessM crippledFileSystem $
+		unlessM (inRepo $ Git.hookWrite h) $
+			hookWarning h "already exists, not configuring"
+
+hookUnWrite :: Git.Hook -> Annex ()
+hookUnWrite h = unlessM (inRepo $ Git.hookUnWrite h) $
+	hookWarning h "contents modified; not deleting. Edit it to remove call to git annex."
+
+hookWarning :: Git.Hook -> String -> Annex ()
+hookWarning h msg = do
+	r <- gitRepo
+	warning $ Git.hookName h ++ " hook (" ++ Git.hookFile h r ++ ") " ++ msg
diff --git a/Annex/Journal.hs b/Annex/Journal.hs
new file mode 100644
index 000000000..8b88ab2fb
--- /dev/null
+++ b/Annex/Journal.hs
@@ -0,0 +1,128 @@
+{- management of the git-annex journal
+ -
+ - The journal is used to queue up changes before they are committed to the
+ - git-annex branch. Among other things, it ensures that if git-annex is
+ - interrupted, its recorded data is not lost.
+ -
+ - Copyright 2011-2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Annex.Journal where
+
+import System.IO.Binary
+
+import Common.Annex
+import Annex.Exception
+import qualified Git
+import Annex.Perms
+
+{- Records content for a file in the branch to the journal.
+ -
+ - Using the journal, rather than immediatly staging content to the index
+ - avoids git needing to rewrite the index after every change.
+ - 
+ - The file in the journal is updated atomically, which allows
+ - getJournalFileStale to always return a consistent journal file
+ - content, although possibly not the most current one.
+ -}
+setJournalFile :: JournalLocked -> FilePath -> String -> Annex ()
+setJournalFile _jl file content = do
+	createAnnexDirectory =<< fromRepo gitAnnexJournalDir
+	createAnnexDirectory =<< fromRepo gitAnnexTmpDir
+	-- journal file is written atomically
+	jfile <- fromRepo $ journalFile file
+	tmp <- fromRepo gitAnnexTmpDir
+	let tmpfile = tmp </> takeFileName jfile
+	liftIO $ do
+		writeBinaryFile tmpfile content
+		moveFile tmpfile jfile
+
+{- Gets any journalled content for a file in the branch. -}
+getJournalFile :: JournalLocked -> FilePath -> Annex (Maybe String)
+getJournalFile _jl = getJournalFileStale
+
+{- Without locking, this is not guaranteed to be the most recent
+ - version of the file in the journal, so should not be used as a basis for
+ - changes. -}
+getJournalFileStale :: FilePath -> Annex (Maybe String)
+getJournalFileStale file = inRepo $ \g -> catchMaybeIO $
+	readFileStrict $ journalFile file g
+
+{- List of files that have updated content in the journal. -}
+getJournalledFiles :: JournalLocked -> Annex [FilePath]
+getJournalledFiles jl = map fileJournal <$> getJournalFiles jl
+
+getJournalledFilesStale :: Annex [FilePath]
+getJournalledFilesStale = map fileJournal <$> getJournalFilesStale
+
+{- List of existing journal files. -}
+getJournalFiles :: JournalLocked -> Annex [FilePath]
+getJournalFiles _jl = getJournalFilesStale
+
+{- List of existing journal files, but without locking, may miss new ones
+ - just being added, or may have false positives if the journal is staged
+ - as it is run. -}
+getJournalFilesStale :: Annex [FilePath]
+getJournalFilesStale = do
+	g <- gitRepo
+	fs <- liftIO $ catchDefaultIO [] $
+		getDirectoryContents $ gitAnnexJournalDir g
+	return $ filter (`notElem` [".", ".."]) fs
+
+{- Checks if there are changes in the journal. -}
+journalDirty :: Annex Bool
+journalDirty = not . null <$> getJournalFilesStale
+
+{- Produces a filename to use in the journal for a file on the branch.
+ -
+ - The journal typically won't have a lot of files in it, so the hashing
+ - used in the branch is not necessary, and all the files are put directly
+ - in the journal directory.
+ -}
+journalFile :: FilePath -> Git.Repo -> FilePath
+journalFile file repo = gitAnnexJournalDir repo </> concatMap mangle file
+  where
+	mangle c
+		| c == pathSeparator = "_"
+		| c == '_' = "__"
+		| otherwise = [c]
+
+{- Converts a journal file (relative to the journal dir) back to the
+ - filename on the branch. -}
+fileJournal :: FilePath -> FilePath
+fileJournal = replace [pathSeparator, pathSeparator] "_" .
+	replace "_" [pathSeparator]
+
+{- Sentinal value, only produced by lockJournal; required
+ - as a parameter by things that need to ensure the journal is
+ - locked. -}
+data JournalLocked = ProduceJournalLocked
+
+{- Runs an action that modifies the journal, using locking to avoid
+ - contention with other git-annex processes. -}
+lockJournal :: (JournalLocked -> Annex a) -> Annex a
+lockJournal a = do
+	lockfile <- fromRepo gitAnnexJournalLock
+	createAnnexDirectory $ takeDirectory lockfile
+	mode <- annexFileMode
+	bracketIO (lock lockfile mode) unlock (const $ a ProduceJournalLocked)
+  where
+#ifndef mingw32_HOST_OS
+	lock lockfile mode = do
+		l <- noUmask mode $ createFile lockfile mode
+		waitToSetLock l (WriteLock, AbsoluteSeek, 0, 0)
+		return l
+#else
+	lock lockfile _mode = do
+		writeFile lockfile ""
+		return lockfile
+#endif
+#ifndef mingw32_HOST_OS
+	unlock = closeFd
+#else
+	unlock = removeFile
+#endif
diff --git a/Annex/Link.hs b/Annex/Link.hs
new file mode 100644
index 000000000..30d8c2ae8
--- /dev/null
+++ b/Annex/Link.hs
@@ -0,0 +1,105 @@
+{- git-annex links to content
+ -
+ - On file systems that support them, symlinks are used.
+ -
+ - On other filesystems, git instead stores the symlink target in a regular
+ - file.
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Link where
+
+import Common.Annex
+import qualified Annex
+import qualified Git.HashObject
+import qualified Git.UpdateIndex
+import qualified Annex.Queue
+import Git.Types
+import Git.FilePath
+
+type LinkTarget = String
+
+{- Checks if a file is a link to a key. -}
+isAnnexLink :: FilePath -> Annex (Maybe Key)
+isAnnexLink file = maybe Nothing (fileKey . takeFileName) <$> getAnnexLinkTarget file
+
+{- Gets the link target of a symlink.
+ -
+ - On a filesystem that does not support symlinks, fall back to getting the
+ - link target by looking inside the file.
+ -
+ - Returns Nothing if the file is not a symlink, or not a link to annex
+ - content.
+ -}
+getAnnexLinkTarget :: FilePath -> Annex (Maybe LinkTarget)
+getAnnexLinkTarget file = ifM (coreSymlinks <$> Annex.getGitConfig)
+	( check readSymbolicLink $
+		return Nothing
+	, check readSymbolicLink $
+		check probefilecontent $
+			return Nothing
+	)
+  where
+	check getlinktarget fallback = do
+		v <- liftIO $ catchMaybeIO $ getlinktarget file
+		case v of
+			Just l
+				| isLinkToAnnex (fromInternalGitPath l) -> return v
+				| otherwise -> return Nothing
+			Nothing -> fallback
+
+	probefilecontent f = do
+		h <- openFile f ReadMode
+		fileEncoding h
+		-- The first 8k is more than enough to read; link
+		-- files are small.
+		s <- take 8192 <$> hGetContents h
+		-- If we got the full 8k, the file is too large
+		if length s == 8192
+			then do
+				hClose h
+				return ""
+			else do
+				hClose h
+				-- If there are any NUL or newline
+				-- characters, or whitespace, we
+				-- certianly don't have a link to a
+				-- git-annex key.
+				return $ if any (`elem` s) "\0\n\r \t"
+					then ""
+					else s
+
+{- Creates a link on disk.
+ -
+ - On a filesystem that does not support symlinks, writes the link target
+ - to a file. Note that git will only treat the file as a symlink if
+ - it's staged as such, so use addAnnexLink when adding a new file or
+ - modified link to git.
+ -}
+makeAnnexLink :: LinkTarget -> FilePath -> Annex ()
+makeAnnexLink linktarget file = ifM (coreSymlinks <$> Annex.getGitConfig)
+	( liftIO $ do
+		void $ tryIO $ removeFile file
+		createSymbolicLink linktarget file
+	, liftIO $ writeFile file linktarget
+	)
+
+{- Creates a link on disk, and additionally stages it in git. -}
+addAnnexLink :: LinkTarget -> FilePath -> Annex ()
+addAnnexLink linktarget file = do
+	makeAnnexLink linktarget file
+	stageSymlink file =<< hashSymlink linktarget
+
+{- Injects a symlink target into git, returning its Sha. -}
+hashSymlink :: LinkTarget -> Annex Sha
+hashSymlink linktarget = inRepo $ Git.HashObject.hashObject BlobObject $ 
+	toInternalGitPath linktarget
+
+{- Stages a symlink to the annex, using a Sha of its target. -}
+stageSymlink :: FilePath -> Sha -> Annex ()
+stageSymlink file sha =
+	Annex.Queue.addUpdateIndex =<<
+		inRepo (Git.UpdateIndex.stageSymlink file sha)
diff --git a/Annex/LockPool.hs b/Annex/LockPool.hs
new file mode 100644
index 000000000..a9a0f3101
--- /dev/null
+++ b/Annex/LockPool.hs
@@ -0,0 +1,56 @@
+{- git-annex lock pool
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Annex.LockPool where
+
+import qualified Data.Map as M
+import System.Posix.Types (Fd)
+
+import Common.Annex
+import Annex
+#ifndef mingw32_HOST_OS
+import Annex.Perms
+#endif
+
+{- Create a specified lock file, and takes a shared lock. -}
+lockFile :: FilePath -> Annex ()
+lockFile file = go =<< fromPool file
+  where
+	go (Just _) = noop -- already locked
+	go Nothing = do
+#ifndef mingw32_HOST_OS
+		mode <- annexFileMode
+		fd <- liftIO $ noUmask mode $
+			openFd file ReadOnly (Just mode) defaultFileFlags
+		liftIO $ waitToSetLock fd (ReadLock, AbsoluteSeek, 0, 0)
+#else
+		liftIO $ writeFile file ""
+		let fd = 0
+#endif
+		changePool $ M.insert file fd
+
+unlockFile :: FilePath -> Annex ()
+unlockFile file = maybe noop go =<< fromPool file
+  where
+	go fd = do
+#ifndef mingw32_HOST_OS
+		liftIO $ closeFd fd
+#endif
+		changePool $ M.delete file
+
+getPool :: Annex (M.Map FilePath Fd)
+getPool = getState lockpool
+
+fromPool :: FilePath -> Annex (Maybe Fd)
+fromPool file = M.lookup file <$> getPool
+
+changePool :: (M.Map FilePath Fd -> M.Map FilePath Fd) -> Annex ()
+changePool a = do
+	m <- getPool
+	changeState $ \s -> s { lockpool = a m }
diff --git a/Annex/Path.hs b/Annex/Path.hs
new file mode 100644
index 000000000..a8c4907b2
--- /dev/null
+++ b/Annex/Path.hs
@@ -0,0 +1,34 @@
+{- git-annex program path
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Annex.Path where
+
+import Common
+import Config.Files
+import System.Environment
+
+{- A fully qualified path to the currently running git-annex program.
+ - 
+ - getExecutablePath is available since ghc 7.4.2. On OSs it supports
+ - well, it returns the complete path to the program. But, on other OSs,
+ - it might return just the basename.
+ -}
+programPath :: IO (Maybe FilePath)
+programPath = do
+#if MIN_VERSION_base(4,6,0)
+	exe <- getExecutablePath
+	p <- if isAbsolute exe
+		then return exe
+		else readProgramFile
+#else
+	p <- readProgramFile
+#endif
+	-- In case readProgramFile returned just the command name,
+	-- fall back to finding it in PATH.
+	searchPath p
diff --git a/Annex/Perms.hs b/Annex/Perms.hs
new file mode 100644
index 000000000..e3a2fa65a
--- /dev/null
+++ b/Annex/Perms.hs
@@ -0,0 +1,125 @@
+{- git-annex file permissions
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Perms (
+	setAnnexFilePerm,
+	setAnnexDirPerm,
+	annexFileMode,
+	createAnnexDirectory,
+	noUmask,
+	createContentDir,
+	freezeContentDir,
+	thawContentDir,
+	modifyContent,
+) where
+
+import Common.Annex
+import Utility.FileMode
+import Git.SharedRepository
+import qualified Annex
+import Annex.Exception
+import Config
+
+import System.Posix.Types
+
+withShared :: (SharedRepository -> Annex a) -> Annex a
+withShared a = maybe startup a =<< Annex.getState Annex.shared
+  where
+	startup = do
+		shared <- fromRepo getSharedRepository
+		Annex.changeState $ \s -> s { Annex.shared = Just shared }
+		a shared
+
+setAnnexFilePerm :: FilePath -> Annex ()
+setAnnexFilePerm = setAnnexPerm False
+
+setAnnexDirPerm :: FilePath -> Annex ()
+setAnnexDirPerm = setAnnexPerm True
+
+{- Sets appropriate file mode for a file or directory in the annex,
+ - other than the content files and content directory. Normally,
+ - use the default mode, but with core.sharedRepository set,
+ - allow the group to write, etc. -}
+setAnnexPerm :: Bool -> FilePath -> Annex ()
+setAnnexPerm isdir file = unlessM crippledFileSystem $
+	withShared $ liftIO . go
+  where
+	go GroupShared = modifyFileMode file $ addModes $
+		groupSharedModes ++
+		if isdir then [ ownerExecuteMode, groupExecuteMode ] else []
+	go AllShared = modifyFileMode file $ addModes $
+		readModes ++
+		[ ownerWriteMode, groupWriteMode ] ++
+		if isdir then executeModes else []
+	go _ = noop
+
+{- Gets the appropriate mode to use for creating a file in the annex
+ - (other than content files, which are locked down more). -}
+annexFileMode :: Annex FileMode
+annexFileMode = withShared $ return . go
+  where
+	go GroupShared = sharedmode
+	go AllShared = combineModes (sharedmode:readModes)
+	go _ = stdFileMode
+	sharedmode = combineModes groupSharedModes
+
+{- Creates a directory inside the gitAnnexDir, including any parent
+ - directories. Makes directories with appropriate permissions. -}
+createAnnexDirectory :: FilePath -> Annex ()
+createAnnexDirectory dir = traverse dir [] =<< top
+  where
+	top = parentDir <$> fromRepo gitAnnexDir
+	traverse d below stop
+		| d `equalFilePath` stop = done
+		| otherwise = ifM (liftIO $ doesDirectoryExist d)
+			( done
+			, traverse (parentDir d) (d:below) stop
+			)
+	  where
+		done = forM_ below $ \p -> do
+			liftIO $ createDirectoryIfMissing True p
+			setAnnexDirPerm p
+
+{- Blocks writing to the directory an annexed file is in, to prevent the
+ - file accidentially being deleted. However, if core.sharedRepository
+ - is set, this is not done, since the group must be allowed to delete the
+ - file.
+ -}
+freezeContentDir :: FilePath -> Annex ()
+freezeContentDir file = unlessM crippledFileSystem $
+	liftIO . go =<< fromRepo getSharedRepository
+  where
+	dir = parentDir file
+	go GroupShared = groupWriteRead dir
+	go AllShared = groupWriteRead dir
+	go _ = preventWrite dir
+
+thawContentDir :: FilePath -> Annex ()
+thawContentDir file = unlessM crippledFileSystem $
+	liftIO $ allowWrite $ parentDir file
+
+{- Makes the directory tree to store an annexed file's content,
+ - with appropriate permissions on each level. -}
+createContentDir :: FilePath -> Annex ()
+createContentDir dest = do
+	unlessM (liftIO $ doesDirectoryExist dir) $
+		createAnnexDirectory dir 
+	-- might have already existed with restricted perms
+	unlessM crippledFileSystem $
+		liftIO $ allowWrite dir
+  where
+	dir = parentDir dest
+
+{- Creates the content directory for a file if it doesn't already exist,
+ - or thaws it if it does, then runs an action to modify the file, and
+ - finally, freezes the content directory. -}
+modifyContent :: FilePath -> Annex a -> Annex a
+modifyContent f a = do
+	createContentDir f -- also thaws it
+	v <- tryAnnex a
+	freezeContentDir f
+	either throwAnnex return v
diff --git a/Annex/Queue.hs b/Annex/Queue.hs
new file mode 100644
index 000000000..a5ef60037
--- /dev/null
+++ b/Annex/Queue.hs
@@ -0,0 +1,62 @@
+{- git-annex command queue
+ -
+ - Copyright 2011, 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Queue (
+	addCommand,
+	addUpdateIndex,
+	flush,
+	flushWhenFull,
+	size
+) where
+
+import Common.Annex
+import Annex hiding (new)
+import qualified Git.Queue
+import qualified Git.UpdateIndex
+
+{- Adds a git command to the queue. -}
+addCommand :: String -> [CommandParam] -> [FilePath] -> Annex ()
+addCommand command params files = do
+	q <- get
+	store <=< inRepo $ Git.Queue.addCommand command params files q
+
+{- Adds an update-index stream to the queue. -}
+addUpdateIndex :: Git.UpdateIndex.Streamer -> Annex ()
+addUpdateIndex streamer = do
+	q <- get
+	store <=< inRepo $ Git.Queue.addUpdateIndex streamer q
+
+{- Runs the queue if it is full. Should be called periodically. -}
+flushWhenFull :: Annex ()
+flushWhenFull = do
+	q <- get
+	when (Git.Queue.full q) flush
+
+{- Runs (and empties) the queue. -}
+flush :: Annex ()
+flush = do
+	q <- get
+	unless (0 == Git.Queue.size q) $ do
+		showStoringStateAction
+		q' <- inRepo $ Git.Queue.flush q
+		store q'
+
+{- Gets the size of the queue. -}
+size :: Annex Int
+size = Git.Queue.size <$> get
+
+get :: Annex Git.Queue.Queue
+get = maybe new return =<< getState repoqueue
+
+new :: Annex Git.Queue.Queue
+new = do
+	q <- Git.Queue.new . annexQueueSize <$> getGitConfig
+	store q
+	return q
+
+store :: Git.Queue.Queue -> Annex ()
+store q = changeState $ \s -> s { repoqueue = Just q }
diff --git a/Annex/Quvi.hs b/Annex/Quvi.hs
new file mode 100644
index 000000000..b0725bae7
--- /dev/null
+++ b/Annex/Quvi.hs
@@ -0,0 +1,20 @@
+{- quvi options for git-annex
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE Rank2Types #-}
+
+module Annex.Quvi where
+
+import Common.Annex
+import qualified Annex
+import Utility.Quvi
+import Utility.Url
+
+withQuviOptions :: forall a. Query a -> [CommandParam] -> URLString -> Annex a
+withQuviOptions a ps url = do
+	opts <- map Param . annexQuviOptions <$> Annex.getGitConfig
+	liftIO $ a (ps++opts) url
diff --git a/Annex/ReplaceFile.hs b/Annex/ReplaceFile.hs
new file mode 100644
index 000000000..dd93b471c
--- /dev/null
+++ b/Annex/ReplaceFile.hs
@@ -0,0 +1,39 @@
+{- git-annex file replacing
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.ReplaceFile where
+
+import Common.Annex
+import Annex.Perms
+import Annex.Exception
+
+{- Replaces a possibly already existing file with a new version, 
+ - atomically, by running an action.
+ - 
+ - The action is passed a temp file, which it can write to, and once
+ - done the temp file is moved into place.
+ -
+ - The action can throw an IO exception, in which case the temp file
+ - will be deleted, and the existing file will be preserved.
+ -
+ - Throws an IO exception when it was unable to replace the file.
+ -}
+replaceFile :: FilePath -> (FilePath -> Annex ()) -> Annex ()
+replaceFile file a = do
+	tmpdir <- fromRepo gitAnnexTmpDir
+	void $ createAnnexDirectory tmpdir
+	bracketIO (setup tmpdir) nukeFile $ \tmpfile -> do
+		a tmpfile
+		liftIO $ catchIO (rename tmpfile file) (fallback tmpfile)
+  where
+  	setup tmpdir = do
+		(tmpfile, h) <- openTempFileWithDefaultPermissions tmpdir "tmp"
+		hClose h
+		return tmpfile
+	fallback tmpfile _ = do
+		createDirectoryIfMissing True $ parentDir file
+		rename tmpfile file
diff --git a/Annex/Ssh.hs b/Annex/Ssh.hs
new file mode 100644
index 000000000..8553ee797
--- /dev/null
+++ b/Annex/Ssh.hs
@@ -0,0 +1,198 @@
+{- git-annex ssh interface, with connection caching
+ -
+ - Copyright 2012,2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Annex.Ssh (
+	sshCachingOptions,
+	sshCleanup,
+	sshCacheDir,
+	sshReadPort,
+) where
+
+import qualified Data.Map as M
+import Data.Hash.MD5
+import System.Process (cwd)
+
+import Common.Annex
+import Annex.LockPool
+import qualified Build.SysConfig as SysConfig
+import qualified Annex
+import Config
+import Utility.Env
+#ifndef mingw32_HOST_OS
+import Annex.Perms
+#endif
+
+{- Generates parameters to ssh to a given host (or user@host) on a given
+ - port, with connection caching. -}
+sshCachingOptions :: (String, Maybe Integer) -> [CommandParam] -> Annex [CommandParam]
+sshCachingOptions (host, port) opts = go =<< sshInfo (host, port)
+  where
+	go (Nothing, params) = ret params
+	go (Just socketfile, params) = do
+		cleanstale
+		liftIO $ createDirectoryIfMissing True $ parentDir socketfile
+		lockFile $ socket2lock socketfile
+		ret params
+	ret ps = return $ ps ++ opts ++ portParams port ++ [Param "-T"]
+	-- If the lock pool is empty, this is the first ssh of this
+	-- run. There could be stale ssh connections hanging around
+	-- from a previous git-annex run that was interrupted.
+	cleanstale = whenM (not . any isLock . M.keys <$> getPool)
+		sshCleanup
+
+{- Returns a filename to use for a ssh connection caching socket, and
+ - parameters to enable ssh connection caching. -}
+sshInfo :: (String, Maybe Integer) -> Annex (Maybe FilePath, [CommandParam])
+sshInfo (host, port) = go =<< sshCacheDir
+  where
+	go Nothing = return (Nothing, [])
+	go (Just dir) = do
+		r <- liftIO $ bestSocketPath $ dir </> hostport2socket host port
+		return $ case r of
+			Nothing -> (Nothing, [])
+			Just socketfile -> (Just socketfile, sshConnectionCachingParams socketfile)
+
+{- Given an absolute path to use for a socket file,
+ - returns whichever is shorter of that or the relative path to the same
+ - file.
+ -
+ - If no path can be constructed that is a valid socket, returns Nothing. -}
+bestSocketPath :: FilePath -> IO (Maybe FilePath)
+bestSocketPath abssocketfile = do
+	relsocketfile <- liftIO $ relPathCwdToFile abssocketfile
+	let socketfile = if length abssocketfile <= length relsocketfile
+		then abssocketfile
+		else relsocketfile
+	return $ if valid_unix_socket_path (socketfile ++ sshgarbage)
+			then Just socketfile
+			else Nothing
+  where
+  	-- ssh appends a 16 char extension to the socket when setting it
+	-- up, which needs to be taken into account when checking
+	-- that a valid socket was constructed.
+  	sshgarbage = take (1+16) $ repeat 'X'
+
+sshConnectionCachingParams :: FilePath -> [CommandParam]
+sshConnectionCachingParams socketfile = 
+	[ Param "-S", Param socketfile
+	, Params "-o ControlMaster=auto -o ControlPersist=yes"
+	]
+
+{- ssh connection caching creates sockets, so will not work on a
+ - crippled filesystem. A GIT_ANNEX_TMP_DIR can be provided to use
+ - a different filesystem. -}
+sshCacheDir :: Annex (Maybe FilePath)
+sshCacheDir
+	| SysConfig.sshconnectioncaching = ifM crippledFileSystem
+		( maybe (return Nothing) usetmpdir =<< gettmpdir
+		, ifM (fromMaybe True . annexSshCaching <$> Annex.getGitConfig)
+			( Just <$> fromRepo gitAnnexSshDir
+			, return Nothing
+			)
+		)
+	| otherwise = return Nothing
+  where
+	gettmpdir = liftIO $ getEnv "GIT_ANNEX_TMP_DIR"
+	usetmpdir tmpdir = liftIO $ catchMaybeIO $ do
+		createDirectoryIfMissing True tmpdir
+		return tmpdir
+
+portParams :: Maybe Integer -> [CommandParam]
+portParams Nothing = []
+portParams (Just port) = [Param "-p", Param $ show port]
+
+{- Stop any unused ssh processes. -}
+sshCleanup :: Annex ()
+sshCleanup = go =<< sshCacheDir
+  where
+	go Nothing = noop
+	go (Just dir) = do
+		sockets <- liftIO $ filter (not . isLock)
+			<$> catchDefaultIO [] (dirContents dir)
+		forM_ sockets cleanup
+	cleanup socketfile = do
+#ifndef mingw32_HOST_OS
+		-- Drop any shared lock we have, and take an
+		-- exclusive lock, without blocking. If the lock
+		-- succeeds, nothing is using this ssh, and it can
+		-- be stopped.
+		let lockfile = socket2lock socketfile
+		unlockFile lockfile
+		mode <- annexFileMode
+		fd <- liftIO $ noUmask mode $
+			openFd lockfile ReadWrite (Just mode) defaultFileFlags
+		v <- liftIO $ tryIO $
+			setLock fd (WriteLock, AbsoluteSeek, 0, 0)
+		case v of
+			Left _ -> noop
+			Right _ -> stopssh socketfile
+		liftIO $ closeFd fd
+#else
+		stopssh socketfile
+#endif
+	stopssh socketfile = do
+		let (dir, base) = splitFileName socketfile
+		let params = sshConnectionCachingParams base
+		-- "ssh -O stop" is noisy on stderr even with -q
+		void $ liftIO $ catchMaybeIO $
+			withQuietOutput createProcessSuccess $
+				(proc "ssh" $ toCommand $
+					[ Params "-O stop"
+					] ++ params ++ [Param "any"])
+					{ cwd = Just dir }
+		-- Cannot remove the lock file; other processes may
+		-- be waiting on our exclusive lock to use it.
+
+{- This needs to be as short as possible, due to limitations on the length
+ - of the path to a socket file. At the same time, it needs to be unique
+ - for each host.
+ -}
+hostport2socket :: String -> Maybe Integer -> FilePath
+hostport2socket host Nothing = hostport2socket' host
+hostport2socket host (Just port) = hostport2socket' $ host ++ "!" ++ show port
+hostport2socket' :: String -> FilePath
+hostport2socket' s
+	| length s > lengthofmd5s = md5s (Str s)
+	| otherwise = s
+  where
+	lengthofmd5s = 32
+
+socket2lock :: FilePath -> FilePath
+socket2lock socket = socket ++ lockExt
+
+isLock :: FilePath -> Bool
+isLock f = lockExt `isSuffixOf` f
+
+lockExt :: String
+lockExt = ".lock"
+
+{- This is the size of the sun_path component of sockaddr_un, which
+ - is the limit to the total length of the filename of a unix socket.
+ -
+ - On Linux, this is 108. On OSX, 104. TODO: Probe
+ -}
+sizeof_sockaddr_un_sun_path :: Int
+sizeof_sockaddr_un_sun_path = 100
+
+{- Note that this looks at the true length of the path in bytes, as it will
+ - appear on disk. -}
+valid_unix_socket_path :: FilePath -> Bool
+valid_unix_socket_path f = length (decodeW8 f) < sizeof_sockaddr_un_sun_path
+
+{- Parses the SSH port, and returns the other OpenSSH options. If
+ - several ports are found, the last one takes precedence. -}
+sshReadPort :: [String] -> (Maybe Integer, [String])
+sshReadPort params = (port, reverse args)
+  where
+	(port,args) = aux (Nothing, []) params
+	aux (p,ps) [] = (p,ps)
+	aux (_,ps) ("-p":p:rest) = aux (readPort p, ps) rest
+	aux (p,ps) (q:rest) | "-p" `isPrefixOf` q = aux (readPort $ drop 2 q, ps) rest
+			    | otherwise = aux (p,q:ps) rest
+	readPort p = fmap fst $ listToMaybe $ reads p
diff --git a/Annex/TaggedPush.hs b/Annex/TaggedPush.hs
new file mode 100644
index 000000000..039dc0e17
--- /dev/null
+++ b/Annex/TaggedPush.hs
@@ -0,0 +1,61 @@
+{- git-annex tagged pushes
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.TaggedPush where
+
+import Common.Annex
+import qualified Remote
+import qualified Annex.Branch
+import qualified Git
+import qualified Git.Ref
+import qualified Git.Command
+import qualified Git.Branch
+import Utility.Base64
+
+{- Converts a git branch into a branch that is tagged with a UUID, typically
+ - the UUID of the repo that will be pushing it, and possibly with other
+ - information.
+ -
+ - Pushing to branches on the remote that have our uuid in them is ugly,
+ - but it reserves those branches for pushing by us, and so our pushes will
+ - never conflict with other pushes.
+ -
+ - To avoid cluttering up the branch display, the branch is put under
+ - refs/synced/, rather than the usual refs/remotes/
+ -
+ - Both UUIDs and Base64 encoded data are always legal to be used in git
+ - refs, per git-check-ref-format.
+ -}
+toTaggedBranch :: UUID -> Maybe String -> Git.Branch -> Git.Branch
+toTaggedBranch u info b = Git.Ref $ intercalate "/" $ catMaybes
+	[ Just "refs/synced"
+	, Just $ fromUUID u
+	, toB64 <$> info
+	, Just $ show $ Git.Ref.base b
+	]
+
+fromTaggedBranch :: Git.Branch -> Maybe (UUID, Maybe String)
+fromTaggedBranch b = case split "/" $ show b of
+	("refs":"synced":u:info:_base) ->
+		Just (toUUID u, fromB64Maybe info)
+	("refs":"synced":u:_base) ->
+		Just (toUUID u, Nothing)
+	_ -> Nothing
+  where
+
+taggedPush :: UUID -> Maybe String -> Git.Ref -> Remote -> Git.Repo -> IO Bool
+taggedPush u info branch remote = Git.Command.runBool
+        [ Param "push"
+        , Param $ Remote.name remote
+	{- Using forcePush here is safe because we "own" the tagged branch
+	 - we're pushing; it has no other writers. Ensures it is pushed
+	 - even if it has been rewritten by a transition. -}
+        , Param $ Git.Branch.forcePush $ refspec Annex.Branch.name
+        , Param $ refspec branch
+        ]
+  where
+	refspec b = show b ++ ":" ++ show (toTaggedBranch u info b)
diff --git a/Annex/UUID.hs b/Annex/UUID.hs
new file mode 100644
index 000000000..4e274503b
--- /dev/null
+++ b/Annex/UUID.hs
@@ -0,0 +1,96 @@
+{- git-annex uuids
+ -
+ - Each git repository used by git-annex has an annex.uuid setting that
+ - uniquely identifies that repository.
+ -
+ - UUIDs of remotes are cached in git config, using keys named
+ - remote.<name>.annex-uuid
+ -
+ - Copyright 2010-2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.UUID (
+	getUUID,
+	getRepoUUID,
+	getUncachedUUID,
+	prepUUID,
+	genUUID,
+	genUUIDInNameSpace,
+	gCryptNameSpace,
+	removeRepoUUID,
+	storeUUID,
+	setUUID,
+) where
+
+import Common.Annex
+import qualified Git
+import qualified Git.Config
+import Config
+
+import qualified Data.UUID as U
+import qualified Data.UUID.V5 as U5
+import System.Random
+import Data.Bits.Utils
+
+configkey :: ConfigKey
+configkey = annexConfig "uuid"
+
+{- Generates a random UUID, that does not include the MAC address. -}
+genUUID :: IO UUID
+genUUID = UUID . show <$> (randomIO :: IO U.UUID)
+
+{- Generates a UUID from a given string, using a namespace.
+ - Given the same namespace, the same string will always result
+ - in the same UUID. -}
+genUUIDInNameSpace :: U.UUID -> String -> UUID
+genUUIDInNameSpace namespace = UUID . show . U5.generateNamed namespace . s2w8
+
+{- Namespace used for UUIDs derived from git-remote-gcrypt ids. -}
+gCryptNameSpace :: U.UUID
+gCryptNameSpace = U5.generateNamed U5.namespaceURL $
+	s2w8 "http://git-annex.branchable.com/design/gcrypt/" 
+
+{- Get current repository's UUID. -}
+getUUID :: Annex UUID
+getUUID = getRepoUUID =<< gitRepo
+
+{- Looks up a repo's UUID, caching it in .git/config if it's not already. -}
+getRepoUUID :: Git.Repo -> Annex UUID
+getRepoUUID r = do
+	c <- toUUID <$> getConfig cachekey ""
+	let u = getUncachedUUID r
+	
+	if c /= u && u /= NoUUID
+		then do
+			updatecache u
+			return u
+		else return c
+  where
+	updatecache u = do
+		g <- gitRepo
+		when (g /= r) $ storeUUID cachekey u
+	cachekey = remoteConfig r "uuid"
+
+removeRepoUUID :: Annex ()
+removeRepoUUID = unsetConfig configkey
+
+getUncachedUUID :: Git.Repo -> UUID
+getUncachedUUID = toUUID . Git.Config.get key ""
+  where
+	(ConfigKey key) = configkey
+
+{- Make sure that the repo has an annex.uuid setting. -}
+prepUUID :: Annex ()
+prepUUID = whenM ((==) NoUUID <$> getUUID) $
+	storeUUID configkey =<< liftIO genUUID
+
+storeUUID :: ConfigKey -> UUID -> Annex ()
+storeUUID configfield = setConfig configfield . fromUUID
+
+{- Only sets the configkey in the Repo; does not change .git/config -}
+setUUID :: Git.Repo -> UUID -> IO Git.Repo
+setUUID r u = do
+	let s = show configkey ++ "=" ++ fromUUID u
+	Git.Config.store s r
diff --git a/Annex/Url.hs b/Annex/Url.hs
new file mode 100644
index 000000000..0401ffe07
--- /dev/null
+++ b/Annex/Url.hs
@@ -0,0 +1,27 @@
+{- Url downloading, with git-annex user agent.
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Url (
+	module U,
+	withUserAgent,
+	getUserAgent,
+) where
+
+import Common.Annex
+import qualified Annex
+import Utility.Url as U
+import qualified Build.SysConfig as SysConfig
+
+defaultUserAgent :: U.UserAgent
+defaultUserAgent = "git-annex/" ++ SysConfig.packageversion
+
+getUserAgent :: Annex (Maybe U.UserAgent)
+getUserAgent = Annex.getState $ 
+	Just . fromMaybe defaultUserAgent . Annex.useragent
+
+withUserAgent :: (Maybe U.UserAgent -> IO a) -> Annex a
+withUserAgent a = liftIO . a =<< getUserAgent
diff --git a/Annex/Version.hs b/Annex/Version.hs
new file mode 100644
index 000000000..2b4a49fd2
--- /dev/null
+++ b/Annex/Version.hs
@@ -0,0 +1,47 @@
+{- git-annex repository versioning
+ -
+ - Copyright 2010,2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Annex.Version where
+
+import Common.Annex
+import Config
+import qualified Annex
+
+type Version = String
+
+defaultVersion :: Version
+defaultVersion = "3"
+
+directModeVersion :: Version
+directModeVersion = "5"
+
+supportedVersions :: [Version]
+supportedVersions = [defaultVersion, directModeVersion]
+
+upgradableVersions :: [Version]
+#ifndef mingw32_HOST_OS
+upgradableVersions = ["0", "1", "2", "4"]
+#else
+upgradableVersions = ["2", "4"]
+#endif
+
+autoUpgradeableVersions :: [Version]
+autoUpgradeableVersions = ["4"]
+
+versionField :: ConfigKey
+versionField = annexConfig "version"
+
+getVersion :: Annex (Maybe Version)
+getVersion = annexVersion <$> Annex.getGitConfig
+
+setVersion :: Version -> Annex ()
+setVersion = setConfig versionField
+
+removeVersion :: Annex ()
+removeVersion = unsetConfig versionField
diff --git a/Annex/Wanted.hs b/Annex/Wanted.hs
new file mode 100644
index 000000000..04dcc1c1c
--- /dev/null
+++ b/Annex/Wanted.hs
@@ -0,0 +1,32 @@
+{- git-annex checking whether content is wanted
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Annex.Wanted where
+
+import Common.Annex
+import Logs.PreferredContent
+import Annex.UUID
+
+import qualified Data.Set as S
+
+{- Check if a file is preferred content for the local repository. -}
+wantGet :: Bool -> AssociatedFile -> Annex Bool
+wantGet def Nothing = return def
+wantGet def (Just file) = isPreferredContent Nothing S.empty file def
+
+{- Check if a file is preferred content for a remote. -}
+wantSend :: Bool -> AssociatedFile -> UUID -> Annex Bool
+wantSend def Nothing _ = return def
+wantSend def (Just file) to = isPreferredContent (Just to) S.empty file def
+
+{- Check if a file can be dropped, maybe from a remote.
+ - Don't drop files that are preferred content. -}
+wantDrop :: Bool -> Maybe UUID -> AssociatedFile -> Annex Bool
+wantDrop def _ Nothing = return $ not def
+wantDrop def from (Just file) = do
+	u <- maybe getUUID (return . id) from
+	not <$> isPreferredContent (Just u) (S.singleton u) file def