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.

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 }

Remote/Git.hs

@@ -19,6 +19,7 @@ import qualified Git
 import qualified Annex
 import Annex.UUID
 import qualified Annex.Content
+import qualified Annex.Branch
 import qualified Utility.Url as Url
 import Utility.TempFile
 import Config
@@ -133,7 +134,7 @@ inAnnex r key
 	| Git.repoIsUrl r = checkremote
 	| otherwise = safely checklocal
 	where
-		checklocal = onLocal r (Annex.Content.inAnnex key)
+		checklocal = onLocal r $ Annex.Content.inAnnex key
 		checkremote = do
 			showAction $ "checking " ++ Git.repoDescribe r
 			inannex <- onRemote r (boolSystem, False) "inannex" 
@@ -147,7 +148,11 @@ inAnnex r key
 onLocal :: Git.Repo -> Annex a -> IO a
 onLocal r a = do
 	annex <- Annex.new r
-	Annex.eval annex a
+	Annex.eval annex $ do
+		-- No need to update the branch; its data is not used
+		-- for anything onLocal is used to do.
+		Annex.Branch.disableUpdate
+		a
 
 keyUrl :: Git.Repo -> Key -> String
 keyUrl r key = Git.repoLocation r ++ "/" ++ annexLocation key
@@ -175,11 +180,8 @@ copyToRemote r key
 		g <- gitRepo
 		let keysrc = gitAnnexLocation g key
 		-- run copy from perspective of remote
-		liftIO $ onLocal r $ do
-			ok <- Annex.Content.getViaTmp key $
-				rsyncOrCopyFile r keysrc
-			Annex.Content.saveState
-			return ok
+		liftIO $ onLocal r $ Annex.Content.getViaTmp key $
+			rsyncOrCopyFile r keysrc
 	| Git.repoIsSsh r = do
 		g <- gitRepo
 		let keysrc = gitAnnexLocation g key

debian/changelog

@@ -1,3 +1,9 @@
+git-annex (3.20111026) UNRELEASED; urgency=low
+
+  * Sped up some operations on remotes that are on the same host.
+
+ -- Joey Hess <joeyh@debian.org>  Thu, 27 Oct 2011 13:58:53 -0400
+
 git-annex (3.20111025) unstable; urgency=low
 
   * A remote can have a annexUrl configured, that is used by git-annex