{-# LANGUAGE OverloadedStrings #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE CPP #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE ScopedTypeVariables #-} -- | A sqlite backend for persistent. module Database.Persist.Sqlite ( withSqlitePool , withSqliteConn , createSqlitePool , module Database.Persist.Sql , SqliteConf (..) , runSqlite , wrapConnection ) where import Database.Persist.Sql import qualified Database.Sqlite as Sqlite import Control.Monad.IO.Class (MonadIO (..)) import Control.Monad.Logger (NoLoggingT, runNoLoggingT) import Data.List (intercalate) import Data.IORef import qualified Data.Map as Map import Control.Monad.Trans.Control (control) import qualified Control.Exception as E import Data.Text (Text, pack) import Control.Monad (mzero) import Data.Aeson import qualified Data.Text as T import Data.Conduit import qualified Data.Conduit.List as CL import Control.Applicative import Data.Int (Int64) import Control.Monad ((>=>)) createSqlitePool :: MonadIO m => Text -> Int -> m ConnectionPool createSqlitePool s = createSqlPool $ open' s withSqlitePool :: (MonadBaseControl IO m, MonadIO m) => Text -> Int -- ^ number of connections to open -> (ConnectionPool -> m a) -> m a withSqlitePool s = withSqlPool $ open' s withSqliteConn :: (MonadBaseControl IO m, MonadIO m) => Text -> (Connection -> m a) -> m a withSqliteConn = withSqlConn . open' open' :: Text -> IO Connection open' = Sqlite.open >=> wrapConnection -- | Wrap up a raw 'Sqlite.Connection' as a Persistent SQL 'Connection'. -- -- Since 1.1.5 wrapConnection :: Sqlite.Connection -> IO Connection wrapConnection conn = do smap <- newIORef $ Map.empty return Connection { connPrepare = prepare' conn , connStmtMap = smap , connInsertSql = insertSql' , connClose = Sqlite.close conn , connMigrateSql = migrate' , connBegin = helper "BEGIN" , connCommit = helper "COMMIT" , connRollback = ignoreExceptions . helper "ROLLBACK" , connEscapeName = escape , connNoLimit = "LIMIT -1" , connRDBMS = "sqlite" , connLimitOffset = decorateSQLWithLimitOffset "LIMIT -1" } where helper t getter = do stmt <- getter t _ <- stmtExecute stmt [] stmtReset stmt ignoreExceptions = E.handle (\(_ :: E.SomeException) -> return ()) -- | A convenience helper which creates a new database connection and runs the -- given block, handling @MonadResource@ and @MonadLogger@ requirements. Note -- that all log messages are discarded. -- -- Since 1.1.4 runSqlite :: (MonadBaseControl IO m, MonadIO m) => Text -- ^ connection string -> SqlPersistT (NoLoggingT (ResourceT m)) a -- ^ database action -> m a runSqlite connstr = runResourceT . runNoLoggingT . withSqliteConn connstr . runSqlConn prepare' :: Sqlite.Connection -> Text -> IO Statement prepare' conn sql = do stmt <- Sqlite.prepare conn sql return Statement { stmtFinalize = Sqlite.finalize stmt , stmtReset = Sqlite.reset conn stmt , stmtExecute = execute' conn stmt , stmtQuery = withStmt' conn stmt } insertSql' :: EntityDef SqlType -> [PersistValue] -> InsertSqlResult insertSql' ent vals = case entityPrimary ent of Just _ -> ISRManyKeys sql vals where sql = pack $ concat [ "INSERT INTO " , escape' $ entityDB ent , "(" , intercalate "," $ map (escape' . fieldDB) $ entityFields ent , ") VALUES(" , intercalate "," (map (const "?") $ entityFields ent) , ")" ] Nothing -> ISRInsertGet (pack ins) sel where sel = "SELECT last_insert_rowid()" ins = concat [ "INSERT INTO " , escape' $ entityDB ent , "(" , intercalate "," $ map (escape' . fieldDB) $ entityFields ent , ") VALUES(" , intercalate "," (map (const "?") $ entityFields ent) , ")" ] execute' :: Sqlite.Connection -> Sqlite.Statement -> [PersistValue] -> IO Int64 execute' conn stmt vals = flip finally (liftIO $ Sqlite.reset conn stmt) $ do Sqlite.bind stmt vals _ <- Sqlite.step stmt Sqlite.changes conn withStmt' :: MonadResource m => Sqlite.Connection -> Sqlite.Statement -> [PersistValue] -> Source m [PersistValue] withStmt' conn stmt vals = bracketP (Sqlite.bind stmt vals >> return stmt) (Sqlite.reset conn) (const pull) where pull = do x <- liftIO $ Sqlite.step stmt case x of Sqlite.Done -> return () Sqlite.Row -> do cols <- liftIO $ Sqlite.columns stmt yield cols pull showSqlType :: SqlType -> Text showSqlType SqlString = "VARCHAR" showSqlType SqlInt32 = "INTEGER" showSqlType SqlInt64 = "INTEGER" showSqlType SqlReal = "REAL" showSqlType (SqlNumeric precision scale) = pack $ "NUMERIC(" ++ show precision ++ "," ++ show scale ++ ")" showSqlType SqlDay = "DATE" showSqlType SqlTime = "TIME" showSqlType SqlDayTimeZoned = "TIMESTAMP" showSqlType SqlDayTime = "TIMESTAMP" showSqlType SqlBlob = "BLOB" showSqlType SqlBool = "BOOLEAN" showSqlType (SqlOther t) = t migrate' :: [EntityDef a] -> (Text -> IO Statement) -> EntityDef SqlType -> IO (Either [Text] [(Bool, Text)]) migrate' allDefs getter val = do let (cols, uniqs, _) = mkColumns allDefs val let newSql = mkCreateTable False def (filter (not . safeToRemove val . cName) cols, uniqs) stmt <- getter "SELECT sql FROM sqlite_master WHERE type='table' AND name=?" oldSql' <- runResourceT $ stmtQuery stmt [PersistText $ unDBName table] $$ go case oldSql' of Nothing -> return $ Right [(False, newSql)] Just oldSql -> do if oldSql == newSql then return $ Right [] else do sql <- getCopyTable allDefs getter val return $ Right sql where def = val table = entityDB def go = do x <- CL.head case x of Nothing -> return Nothing Just [PersistText y] -> return $ Just y Just y -> error $ "Unexpected result from sqlite_master: " ++ show y -- | Check if a column name is listed as the "safe to remove" in the entity -- list. safeToRemove :: EntityDef a -> DBName -> Bool safeToRemove def (DBName colName) = any (elem "SafeToRemove" . fieldAttrs) $ filter ((== (DBName colName)) . fieldDB) $ entityFields def getCopyTable :: [EntityDef a] -> (Text -> IO Statement) -> EntityDef SqlType -> IO [(Bool, Text)] getCopyTable allDefs getter val = do stmt <- getter $ pack $ "PRAGMA table_info(" ++ escape' table ++ ")" oldCols' <- runResourceT $ stmtQuery stmt [] $$ getCols let oldCols = map DBName $ filter (/= "id") oldCols' -- need to update for table id attribute ? let newCols = filter (not . safeToRemove def) $ map cName cols let common = filter (`elem` oldCols) newCols let id_ = entityID val return [ (False, tmpSql) , (False, copyToTemp $ id_ : common) , (common /= filter (not . safeToRemove def) oldCols, pack dropOld) , (False, newSql) , (False, copyToFinal $ id_ : newCols) , (False, pack dropTmp) ] where def = val getCols = do x <- CL.head case x of Nothing -> return [] Just (_:PersistText name:_) -> do names <- getCols return $ name : names Just y -> error $ "Invalid result from PRAGMA table_info: " ++ show y table = entityDB def tableTmp = DBName $ unDBName table `T.append` "_backup" (cols, uniqs, _) = mkColumns allDefs val cols' = filter (not . safeToRemove def . cName) cols newSql = mkCreateTable False def (cols', uniqs) tmpSql = mkCreateTable True def { entityDB = tableTmp } (cols', uniqs) dropTmp = "DROP TABLE " ++ escape' tableTmp dropOld = "DROP TABLE " ++ escape' table copyToTemp common = pack $ concat [ "INSERT INTO " , escape' tableTmp , "(" , intercalate "," $ map escape' common , ") SELECT " , intercalate "," $ map escape' common , " FROM " , escape' table ] copyToFinal newCols = pack $ concat [ "INSERT INTO " , T.unpack $ escape table , " SELECT " , intercalate "," $ map escape' newCols , " FROM " , escape' tableTmp ] escape' :: DBName -> String escape' = T.unpack . escape mkCreateTable :: Bool -> EntityDef a -> ([Column], [UniqueDef]) -> Text mkCreateTable isTemp entity (cols, uniqs) = case entityPrimary entity of Just _ -> T.concat [ "CREATE" , if isTemp then " TEMP" else "" , " TABLE " , escape $ entityDB entity , "(" , T.drop 1 $ T.concat $ map sqlColumn cols , ", PRIMARY KEY " , "(" , T.intercalate "," $ map (escape . fieldDB) $ entityFields entity , ")" , ")" ] Nothing -> T.concat [ "CREATE" , if isTemp then " TEMP" else "" , " TABLE " , escape $ entityDB entity , "(" , escape $ entityID entity , " INTEGER PRIMARY KEY" , T.concat $ map sqlColumn cols , T.concat $ map sqlUnique uniqs , ")" ] sqlColumn :: Column -> Text sqlColumn (Column name isNull typ def _cn _maxLen ref) = T.concat [ "," , escape name , " " , showSqlType typ , if isNull then " NULL" else " NOT NULL" , case def of Nothing -> "" Just d -> " DEFAULT " `T.append` d , case ref of Nothing -> "" Just (table, _) -> " REFERENCES " `T.append` escape table ] sqlUnique :: UniqueDef -> Text sqlUnique (UniqueDef _ cname cols _) = T.concat [ ",CONSTRAINT " , escape cname , " UNIQUE (" , T.intercalate "," $ map (escape . snd) cols , ")" ] escape :: DBName -> Text escape (DBName s) = T.concat [q, T.concatMap go s, q] where q = T.singleton '"' go '"' = "\"\"" go c = T.singleton c -- | Information required to connect to a sqlite database data SqliteConf = SqliteConf { sqlDatabase :: Text , sqlPoolSize :: Int } instance PersistConfig SqliteConf where type PersistConfigBackend SqliteConf = SqlPersistT type PersistConfigPool SqliteConf = ConnectionPool createPoolConfig (SqliteConf cs size) = createSqlitePool cs size runPool _ = runSqlPool loadConfig (Object o) = SqliteConf <$> o .: "database" <*> o .: "poolsize" loadConfig _ = mzero finally :: MonadBaseControl IO m => m a -- ^ computation to run first -> m b -- ^ computation to run afterward (even if an exception was raised) -> m a finally a sequel = control $ \runInIO -> E.finally (runInIO a) (runInIO sequel) {-# INLINABLE finally #-}