git-annex/Database/Fsck.hs
Joey Hess ecb0d5c087 use lock pools throughout git-annex
The one exception is in Utility.Daemon. As long as a process only
daemonizes once, which seems reasonable, and as long as it avoids calling
checkDaemon once it's already running as a daemon, the fcntl locking
gotchas won't be a problem there.

Annex.LockFile has it's own separate lock pool layer, which has been
renamed to LockCache. This is a persistent cache of locks that persist
until closed.

This is not quite done; lockContent stil needs to be converted.
2015-05-19 14:09:52 -04:00

100 lines
2.6 KiB
Haskell

{- Sqlite database used for incremental fsck.
-
- Copyright 2015 Joey Hess <id@joeyh.name>
-:
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE QuasiQuotes, TypeFamilies, TemplateHaskell #-}
{-# LANGUAGE OverloadedStrings, GADTs, FlexibleContexts #-}
{-# LANGUAGE MultiParamTypeClasses, GeneralizedNewtypeDeriving #-}
{-# LANGUAGE RankNTypes #-}
module Database.Fsck (
FsckHandle,
newPass,
openDb,
closeDb,
addDb,
inDb,
FsckedId,
) where
import Database.Types
import qualified Database.Handle as H
import Locations
import Utility.PosixFiles
import Utility.Exception
import Common
import Annex
import Types.Key
import Types.UUID
import Annex.Perms
import Annex.LockFile
import Database.Persist.TH
import Database.Esqueleto hiding (Key)
data FsckHandle = FsckHandle H.DbHandle UUID
{- Each key stored in the database has already been fscked as part
- of the latest incremental fsck pass. -}
share [mkPersist sqlSettings, mkMigrate "migrateFsck"] [persistLowerCase|
Fscked
key SKey
UniqueKey key
|]
{- The database is removed when starting a new incremental fsck pass.
-
- This may fail, if other fsck processes are currently running using the
- database. Removing the database in that situation would lead to crashes
- or unknown behavior.
-}
newPass :: UUID -> Annex Bool
newPass u = isJust <$> tryExclusiveLock (gitAnnexFsckDbLock u) go
where
go = liftIO . void . tryIO . removeDirectoryRecursive
=<< fromRepo (gitAnnexFsckDbDir u)
{- Opens the database, creating it atomically if it doesn't exist yet. -}
openDb :: UUID -> Annex FsckHandle
openDb u = do
dbdir <- fromRepo (gitAnnexFsckDbDir u)
let db = dbdir </> "db"
unlessM (liftIO $ doesFileExist db) $ do
let tmpdbdir = dbdir ++ ".tmp"
let tmpdb = tmpdbdir </> "db"
liftIO $ do
createDirectoryIfMissing True tmpdbdir
H.initDb tmpdb $ void $
runMigrationSilent migrateFsck
setAnnexDirPerm tmpdbdir
setAnnexFilePerm tmpdb
liftIO $ do
void $ tryIO $ removeDirectoryRecursive dbdir
rename tmpdbdir dbdir
lockFileCached =<< fromRepo (gitAnnexFsckDbLock u)
h <- liftIO $ H.openDb db "fscked"
return $ FsckHandle h u
closeDb :: FsckHandle -> Annex ()
closeDb (FsckHandle h u) = do
liftIO $ H.closeDb h
unlockFile =<< fromRepo (gitAnnexFsckDbLock u)
addDb :: FsckHandle -> Key -> IO ()
addDb (FsckHandle h _) k = H.queueDb h 1000 $
void $ insertUnique $ Fscked sk
where
sk = toSKey k
inDb :: FsckHandle -> Key -> IO Bool
inDb (FsckHandle h _) = H.queryDb h . inDb' . toSKey
inDb' :: SKey -> SqlPersistM Bool
inDb' sk = do
r <- select $ from $ \r -> do
where_ (r ^. FsckedKey ==. val sk)
return (r ^. FsckedKey)
return $ not $ null r