fsck: Added --distributed and --expire options, for distributed fsck.

1 files changed, 134 insertions, 52 deletions

diff --git a/Command/Fsck.hs b/Command/Fsck.hs
index 7b8fbddf1..ec89a4351 100644
--- a/Command/Fsck.hs
+++ b/Command/Fsck.hs
@@ -22,6 +22,7 @@ import Annex.Direct
 import Annex.Perms
 import Annex.Link
 import Logs.Location
+import Logs.Presence
 import Logs.Trust
 import Config.NumCopies
 import Annex.UUID
@@ -38,6 +39,7 @@ import Data.Time.Clock.POSIX
 import Data.Time
 import System.Posix.Types (EpochTime)
 import System.Locale
+import qualified Data.Map as M
 
 cmd :: [Command]
 cmd = [withOptions fsckOptions $ command "fsck" paramPaths seek
@@ -56,12 +58,22 @@ incrementalScheduleOption :: Option
 incrementalScheduleOption = fieldOption [] "incremental-schedule" paramTime
 	"schedule incremental fscking"
 
+distributedOption :: Option
+distributedOption = flagOption [] "distributed" "distributed fsck mode"
+
+expireOption :: Option
+expireOption = fieldOption [] "expire"
+	(paramRepeating $ paramOptional paramRemote ++ ":" ++ paramTime)
+	"distributed expire mode"
+
 fsckOptions :: [Option]
 fsckOptions = 
 	[ fsckFromOption
 	, startIncrementalOption
 	, moreIncrementalOption
 	, incrementalScheduleOption
+	, distributedOption
+	, expireOption
 	] ++ keyOptions ++ annexedMatchingOptions
 
 seek :: CommandSeek
@@ -69,62 +81,28 @@ seek ps = do
 	from <- getOptionField fsckFromOption Remote.byNameWithUUID
 	u <- maybe getUUID (pure . Remote.uuid) from
 	i <- getIncremental u
+	d <- getDistributed
 	withKeyOptions False
-		(\k -> startKey i k =<< getNumCopies)
-		(withFilesInGit $ whenAnnexed $ start from i)
+		(\k -> startKey i d k =<< getNumCopies)
+		(withFilesInGit $ whenAnnexed $ start from i d)
 		ps
 	withFsckDb i FsckDb.closeDb
 
-getIncremental :: UUID -> Annex Incremental
-getIncremental u = do
-	i <- maybe (return False) (checkschedule . parseDuration)
-		=<< Annex.getField (optionName incrementalScheduleOption)
-	starti <- Annex.getFlag (optionName startIncrementalOption)
-	morei <- Annex.getFlag (optionName moreIncrementalOption)
-	case (i, starti, morei) of
-		(False, False, False) -> return NonIncremental
-		(False, True, False) -> startIncremental
-		(False ,False, True) -> contIncremental
-		(True, False, False) ->
-			maybe startIncremental (const contIncremental)
-				=<< getStartTime u
-		_ -> error "Specify only one of --incremental, --more, or --incremental-schedule"
-  where
-	startIncremental = do
-		recordStartTime u
-		ifM (FsckDb.newPass u)
-			( StartIncremental <$> FsckDb.openDb u
-			, error "Cannot start a new --incremental fsck pass; another fsck process is already running."
-			)
-	contIncremental = ContIncremental <$> FsckDb.openDb u
-
-	checkschedule Nothing = error "bad --incremental-schedule value"
-	checkschedule (Just 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
-		return True
-
-start :: Maybe Remote -> Incremental -> FilePath -> Key -> CommandStart
-start from inc file key = do
+start :: Maybe Remote -> Incremental -> Distributed -> FilePath -> Key -> CommandStart
+start from inc dist file key = do
 	v <- Backend.getBackend file key
 	case v of
 		Nothing -> stop
 		Just backend -> do
 			numcopies <- getFileNumCopies file
 			case from of
-				Nothing -> go $ perform key file backend numcopies
-				Just r -> go $ performRemote key file backend numcopies r
+				Nothing -> go $ perform dist key file backend numcopies
+				Just r -> go $ performRemote dist key file backend numcopies r
   where
 	go = runFsck inc file key
 
-perform :: Key -> FilePath -> Backend -> NumCopies -> Annex Bool
-perform key file backend numcopies = check
+perform :: Distributed -> Key -> FilePath -> Backend -> NumCopies -> Annex Bool
+perform dist key file backend numcopies = check
 	-- order matters
 	[ fixLink key file
 	, verifyLocationLog key file
@@ -132,13 +110,14 @@ perform key file backend numcopies = check
 	, verifyDirectMode key file
 	, checkKeySize key
 	, checkBackend backend key (Just file)
+	, checkDistributed dist key Nothing
 	, checkKeyNumCopies key file numcopies
 	]
 
 {- To fsck a remote, the content is retrieved to a tmp file,
  - and checked locally. -}
-performRemote :: Key -> FilePath -> Backend -> NumCopies -> Remote -> Annex Bool
-performRemote key file backend numcopies remote =
+performRemote :: Distributed -> Key -> FilePath -> Backend -> NumCopies -> Remote -> Annex Bool
+performRemote dist key file backend numcopies remote =
 	dispatch =<< Remote.hasKey remote key
   where
 	dispatch (Left err) = do
@@ -157,6 +136,7 @@ performRemote key file backend numcopies remote =
 		[ verifyLocationLogRemote key file remote present
 		, checkKeySizeRemote key remote localcopy
 		, checkBackendRemote backend key remote localcopy
+		, checkDistributed dist key (Just $ Remote.uuid remote)
 		, checkKeyNumCopies key file numcopies
 		]
 	withtmp a = do
@@ -177,18 +157,19 @@ performRemote key file backend numcopies remote =
 			)
 	dummymeter _ = noop
 
-startKey :: Incremental -> Key -> NumCopies -> CommandStart
-startKey inc key numcopies =
+startKey :: Incremental -> Distributed -> Key -> NumCopies -> CommandStart
+startKey inc dist key numcopies =
 	case Backend.maybeLookupBackendName (Types.Key.keyBackendName key) of
 		Nothing -> stop
 		Just backend -> runFsck inc (key2file key) key $
-			performKey key backend numcopies
+			performKey dist key backend numcopies
 
-performKey :: Key -> Backend -> NumCopies -> Annex Bool
-performKey key backend numcopies = check
+performKey :: Distributed -> Key -> Backend -> NumCopies -> Annex Bool
+performKey dist key backend numcopies = check
 	[ verifyLocationLog key (key2file key)
 	, checkKeySize key
 	, checkBackend backend key Nothing
+	, checkDistributed dist key Nothing
 	, checkKeyNumCopies key (key2file key) numcopies
 	]
 
@@ -421,8 +402,6 @@ badContentRemote remote key = do
 	return $ (if ok then "dropped from " else "failed to drop from ")
 		++ Remote.name remote
 
-data Incremental = StartIncremental FsckDb.FsckHandle | ContIncremental FsckDb.FsckHandle | NonIncremental
-
 runFsck :: Incremental -> FilePath -> Key -> Annex Bool -> CommandStart
 runFsck inc file key a = ifM (needFsck inc key)
 	( do
@@ -497,3 +476,106 @@ getStartTime u = do
 #else
 		fromfile >= fromstatus
 #endif
+
+data Incremental = StartIncremental FsckDb.FsckHandle | ContIncremental FsckDb.FsckHandle | NonIncremental
+
+getIncremental :: UUID -> Annex Incremental
+getIncremental u = do
+	i <- maybe (return False) (checkschedule . parseDuration)
+		=<< Annex.getField (optionName incrementalScheduleOption)
+	starti <- getOptionFlag startIncrementalOption
+	morei <- getOptionFlag moreIncrementalOption
+	case (i, starti, morei) of
+		(False, False, False) -> return NonIncremental
+		(False, True, False) -> startIncremental
+		(False ,False, True) -> contIncremental
+		(True, False, False) ->
+			maybe startIncremental (const contIncremental)
+				=<< getStartTime u
+		_ -> error "Specify only one of --incremental, --more, or --incremental-schedule"
+  where
+	startIncremental = do
+		recordStartTime u
+		ifM (FsckDb.newPass u)
+			( StartIncremental <$> FsckDb.openDb u
+			, error "Cannot start a new --incremental fsck pass; another fsck process is already running."
+			)
+	contIncremental = ContIncremental <$> FsckDb.openDb u
+
+	checkschedule Nothing = error "bad --incremental-schedule value"
+	checkschedule (Just 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
+		return True
+
+data Distributed
+	= NonDistributed
+	| Distributed POSIXTime
+	| DistributedExpire POSIXTime (M.Map (Maybe UUID) (Maybe POSIXTime))
+	deriving (Show)
+
+getDistributed :: Annex Distributed
+getDistributed = go =<< getOptionField expireOption parseexpire
+  where
+	go (Just m) = DistributedExpire <$> liftIO getPOSIXTime <*> pure m
+	go Nothing = ifM (getOptionFlag distributedOption)
+		( Distributed <$> liftIO getPOSIXTime
+		, return NonDistributed
+		)
+
+	parseexpire Nothing = return Nothing
+	parseexpire (Just s) = do
+		now <- liftIO getPOSIXTime
+		Just . M.fromList <$> mapM (parseexpire' now) (words s)
+	parseexpire' now s = case separate (== ':') s of
+		(t, []) -> return (Nothing, parsetime now t)
+		(n, t) -> do
+			r <- Remote.nameToUUID n
+			return (Just r, parsetime now t)
+	parsetime _ "never" = Nothing
+	parsetime now s = case parseDuration s of
+		Nothing -> error $ "bad expire time: " ++ s
+		Just d -> Just (now - durationToPOSIXTime d)
+
+checkDistributed :: Distributed -> Key -> Maybe UUID -> Annex Bool
+checkDistributed d k mu = do
+	go d
+	return True
+  where
+	go NonDistributed = noop
+
+	-- This is called after fsck has checked the key's content, so
+	-- if the key is present in the annex now, we just need to update
+	-- the location log with the timestamp of the start of the fsck.
+	--
+	-- Note that reusing this timestamp means that the same log line
+	-- is generated for each key, which keeps the size increase
+	-- of the git-annex branch down.
+	go (Distributed ts) = whenM (inAnnex k) $ do
+		u <- maybe getUUID return mu
+		logChange' (logThen ts) k u InfoPresent
+	
+	-- Get the location log for the key, and expire all entries
+	-- that are older than their uuid's listed expiration date.
+	-- (Except for the local repository.)
+	go (DistributedExpire ts m) = do
+		ls <- locationLog k
+		hereu <- getUUID
+		forM_ ls $ \l -> do
+			let u = toUUID (info l)
+			unless (u == hereu) $
+				case lookupexpire u of
+					Just (Just expiretime)
+						| date l < expiretime ->
+							logChange' (logThen ts) k u InfoMissing
+					_ -> noop
+	  where
+		lookupexpire u = headMaybe $ catMaybes $ 
+			map (`M.lookup` m) [Just u, Nothing]
+