Sped up some operations on remotes that are on the same host.

Specifically, disabled trying to update the git-annex branch on the remote,
since that data is never used by operations that act on such remotes.

Also, when copying content to such a remote, skip committing the presence
information changes to its git-annex branch. Leaving it in the journal there
is ok: Any command run on the remote that needs the info will flush the
journal.

This may partially solve this bug:
http://git-annex.branchable.com/bugs/fails_to_handle_lot_of_files/
Although I still see unreaped git processes piling up when doing a copy --to.

1 files changed, 10 insertions, 2 deletions

diff --git a/Annex/Branch.hs b/Annex/Branch.hs
index aea0d2bff..24da8120c 100644
--- a/Annex/Branch.hs
+++ b/Annex/Branch.hs
@@ -8,6 +8,7 @@
 module Annex.Branch (
 	create,
 	update,
+	disableUpdate,
 	get,
 	change,
 	commit,
@@ -136,7 +137,7 @@ update = onceonly $ do
 	c <- filterM changedbranch =<< siblingBranches
 	let (refs, branches) = unzip c
 	unless (not dirty && null refs) $ withIndex $ lockJournal $ do
-		when dirty $ stageJournalFiles
+		when dirty stageJournalFiles
 		g <- gitRepo
 		unless (null branches) $ do
 			showSideAction $ "merging " ++
@@ -164,8 +165,15 @@ update = onceonly $ do
 			return $ not $ L.null diffs
 		onceonly a = unlessM (branchUpdated <$> getState) $ do
 			r <- a
-			Annex.changeState setupdated
+			disableUpdate
 			return r
+
+{- Avoids updating the branch. A useful optimisation when the branc
+ - is known to have not changed, or git-annex won't be relying on info
+ - from it. -}
+disableUpdate :: Annex ()
+disableUpdate = Annex.changeState setupdated
+	where
 		setupdated s = s { Annex.branchstate = new }
 			where
 				new = old { branchUpdated = True }