diff options
author | Joey Hess <joeyh@joeyh.name> | 2015-02-18 15:54:24 -0400 |
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committer | Joey Hess <joeyh@joeyh.name> | 2015-02-18 15:54:24 -0400 |
commit | d8125c9ea6d00b41f994162a0060f39e56107b12 (patch) | |
tree | 3f52039b7be3f4a52a124eb31cdbe341fcc4270f /Database/Fsck.hs | |
parent | d3012ca604d631122f3e304adbb5e60d5d706f82 (diff) |
use WAL mode to ensure read from db always works, even when it's being written to
Also, moved the database to a subdir, as there are multiple files.
This seems to work well with concurrent fscks, although they still do
redundant work due to the commit granularity. Occasionally two writes will
conflict, and one is then deferred and happens later.
Except, with 3 concurrent fscks, I got failures:
git-annex: user error (SQLite3 returned ErrorBusy while attempting to perform prepare "SELECT \"fscked\".\"key\"\nFROM \"fscked\"\nWHERE \"fscked\".\"key\" = ?\n": database is locked)
Argh!!!
Diffstat (limited to 'Database/Fsck.hs')
-rw-r--r-- | Database/Fsck.hs | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/Database/Fsck.hs b/Database/Fsck.hs index 5301109bc..92c814cf1 100644 --- a/Database/Fsck.hs +++ b/Database/Fsck.hs @@ -21,7 +21,8 @@ module Database.Fsck ( import Database.Types import qualified Database.Handle as H import Locations -import Utility.Directory +import Utility.PosixFiles +import Utility.Exception import Annex import Types.Key import Types.UUID @@ -34,6 +35,7 @@ import Control.Monad import Control.Monad.IfElse import Control.Monad.IO.Class (liftIO) import System.Directory +import System.FilePath import Data.Maybe import Control.Applicative @@ -56,20 +58,27 @@ Fscked newPass :: UUID -> Annex Bool newPass u = isJust <$> tryExclusiveLock (gitAnnexFsckDbLock u) go where - go = liftIO. nukeFile =<< fromRepo (gitAnnexFsckDb u) + 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 - db <- fromRepo (gitAnnexFsckDb u) + dbdir <- fromRepo (gitAnnexFsckDbDir u) + let db = dbdir </> "db" unlessM (liftIO $ doesFileExist db) $ do - let newdb = db ++ ".new" - h <- liftIO $ H.openDb newdb - void $ liftIO $ H.commitDb h $ - void $ runMigrationSilent migrateFsck - liftIO $ H.closeDb h - setAnnexFilePerm newdb - liftIO $ renameFile newdb db + let tmpdbdir = dbdir ++ ".tmp" + let tmpdb = tmpdbdir </> "db" + liftIO $ do + createDirectoryIfMissing True tmpdbdir + h <- H.initDb tmpdb $ void $ + runMigrationSilent migrateFsck + H.closeDb h + setAnnexDirPerm tmpdbdir + setAnnexFilePerm tmpdb + liftIO $ do + void $ tryIO $ removeDirectoryRecursive dbdir + rename tmpdbdir dbdir lockFileShared =<< fromRepo (gitAnnexFsckDbLock u) h <- liftIO $ H.openDb db return $ FsckHandle h u |