Improve shutdown due to --time-limit, especially for fsck

* Perform a clean shutdown when --time-limit is reached.
  This includes running queued git commands, and cleanup actions normally
  run when a command is finished.
* fsck: Commit incremental fsck database when --time-limit is reached.
  Previously, some of the last files fscked did not make it into the
  database when using --time-limit.

Note that this changes Annex.addCleanup hooks, to run after --time-limit
expires. Fsck was using such a hook to clean up after a
--incremental-schedule, and that shouldn't run when --time-limit exipires
it. So, instead, moved that cleanup code to be run by cleanupIncremental.
Resulted in some data type juggling.

1 files changed, 30 insertions, 22 deletions

diff --git a/Command/Fsck.hs b/Command/Fsck.hs
index a201c4519..c3b73edb5 100644
--- a/Command/Fsck.hs
+++ b/Command/Fsck.hs
@@ -457,18 +457,12 @@ runFsck inc file key a = ifM (needFsck inc key)
 
 {- Check if a key needs to be fscked, with support for incremental fscks. -}
 needFsck :: Incremental -> Key -> Annex Bool
+needFsck (ScheduleIncremental _ _ i) k = needFsck i k
 #ifdef WITH_DATABASE
 needFsck (ContIncremental h) key = liftIO $ not <$> FsckDb.inDb h key
 #endif
 needFsck _ _ = return True
 
-#ifdef WITH_DATABASE
-withFsckDb :: Incremental -> (FsckDb.FsckHandle -> Annex ()) -> Annex ()
-withFsckDb (ContIncremental h) a = a h
-withFsckDb (StartIncremental h) a = a h
-withFsckDb NonIncremental _ = noop
-#endif
-
 recordFsckTime :: Incremental -> Key -> Annex ()
 #ifdef WITH_DATABASE
 recordFsckTime inc key = withFsckDb inc $ \h -> liftIO $ FsckDb.addDb h key
@@ -527,7 +521,8 @@ data Incremental
 	= NonIncremental
 #ifdef WITH_DATABASE
 	| StartIncremental FsckDb.FsckHandle 
-	| ContIncremental FsckDb.FsckHandle 
+	| ContIncremental FsckDb.FsckHandle
+	| ScheduleIncremental Duration UUID Incremental
 #endif
 
 prepIncremental :: UUID -> Maybe IncrementalOpt -> Annex Incremental
@@ -536,31 +531,44 @@ prepIncremental _ Nothing = pure NonIncremental
 prepIncremental u (Just StartIncrementalO) = do
 	recordStartTime u
 	ifM (FsckDb.newPass u)
-		( StartIncremental <$> FsckDb.openDb u
+		( StartIncremental <$> openFsckDb u
 		, error "Cannot start a new --incremental fsck pass; another fsck process is already running."
 		)
 prepIncremental u (Just MoreIncrementalO) =
-	ContIncremental <$> FsckDb.openDb u
+	ContIncremental <$> openFsckDb u
 prepIncremental u (Just (ScheduleIncrementalO delta)) = do
-	Annex.addCleanup FsckCleanup $ do
-		v <- getStartTime u
-		case v of
-			Nothing -> noop
-			Just started -> do
-				now <- liftIO getPOSIXTime
-				when (now - realToFrac started >= durationToPOSIXTime delta) $
-					resetStartTime u
 	started <- getStartTime u
-	prepIncremental u $ Just $ case started of
+	i <- prepIncremental u $ Just $ case started of
 		Nothing -> StartIncrementalO
 		Just _ -> MoreIncrementalO
+	return (ScheduleIncremental delta u i)
 #else
 prepIncremental _ _ = error "This git-annex was not built with database support; incremental fsck not supported"
 #endif
 
 cleanupIncremental :: Incremental -> Annex ()
-#ifdef WITH_DATABASE
-cleanupIncremental i = withFsckDb i FsckDb.closeDb
-#else
+cleanupIncremental (ScheduleIncremental delta u i) = do
+	v <- getStartTime u
+	case v of
+		Nothing -> noop
+		Just started -> do
+			now <- liftIO getPOSIXTime
+			when (now - realToFrac started >= durationToPOSIXTime delta) $
+				resetStartTime u
+	cleanupIncremental i
 cleanupIncremental _ = return ()
+
+#ifdef WITH_DATABASE
+openFsckDb :: UUID -> Annex FsckDb.FsckHandle
+openFsckDb u = do
+	h <- FsckDb.openDb u
+	Annex.addCleanup FsckCleanup $
+		FsckDb.closeDb h
+	return h
+
+withFsckDb :: Incremental -> (FsckDb.FsckHandle -> Annex ()) -> Annex ()
+withFsckDb (ContIncremental h) a = a h
+withFsckDb (StartIncremental h) a = a h
+withFsckDb NonIncremental _ = noop
+withFsckDb (ScheduleIncremental _ _ i) a = withFsckDb i a
 #endif