git-annex/Database/Init.hs
Joey Hess aa1ad0b7ca
remove redundant imports
Clean build under ghc 8.8.3, which seems to do better at finding cases
where two imports both provide the same symbol, and warns about one of
them.

This commit was sponsored by Ilya Shlyakhter on Patreon.
2020-06-22 11:05:34 -04:00

55 lines
1.7 KiB
Haskell

{- Persistent sqlite database initialization
-
- Copyright 2015-2020 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Database.Init where
import Annex.Common
import Annex.Perms
import Utility.FileMode
import Database.Persist.Sqlite
import qualified Data.Text as T
import Lens.Micro
{- Ensures that the database is freshly initialized. Deletes any
- existing database. Pass the migration action for the database.
-
- The permissions of the database are set based on the
- core.sharedRepository setting. Setting these permissions on the main db
- file causes Sqlite to always use the same permissions for additional
- files it writes later on
-}
initDb :: FilePath -> SqlPersistM () -> Annex ()
initDb db migration = do
let dbdir = takeDirectory db
let tmpdbdir = dbdir ++ ".tmp"
let tmpdb = tmpdbdir </> "db"
let tdb = T.pack tmpdb
top <- parentDir . fromRawFilePath <$> fromRepo gitAnnexDir
liftIO $ do
createDirectoryUnder top tmpdbdir
runSqliteInfo (enableWAL tdb) migration
setAnnexDirPerm tmpdbdir
-- Work around sqlite bug that prevents it from honoring
-- less restrictive umasks.
liftIO $ setFileMode tmpdb =<< defaultFileMode
setAnnexFilePerm tmpdb
liftIO $ do
void $ tryIO $ removeDirectoryRecursive dbdir
rename tmpdbdir dbdir
{- Make sure that the database uses WAL mode, to prevent readers
- from blocking writers, and prevent a writer from blocking readers.
-
- This is the default in recent persistent-sqlite versions, but
- force it on just in case.
-
- Note that once WAL mode is enabled, it will persist whenever the
- database is opened. -}
enableWAL :: T.Text -> SqliteConnectionInfo
enableWAL db = over walEnabled (const True) $
mkSqliteConnectionInfo db