{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE PatternGuards #-}
-- | A sqlite backend for persistent.
--
-- Note: If you prepend @WAL=off @ to your connection string, it will disable
-- the write-ahead log. This functionality is now deprecated in favour of using SqliteConnectionInfo.
module Database.Persist.Sqlite
( withSqlitePool
, withSqlitePoolInfo
, withSqliteConn
, withSqliteConnInfo
, createSqlitePool
, createSqlitePoolFromInfo
, module Database.Persist.Sql
, SqliteConf (..)
, SqliteConnectionInfo
, mkSqliteConnectionInfo
, sqlConnectionStr
, walEnabled
, fkEnabled
, runSqlite
, runSqliteInfo
, wrapConnection
, wrapConnectionInfo
, mockMigration
) where
import Database.Persist.Sql
import Database.Persist.Sql.Types.Internal (mkPersistBackend)
import qualified Database.Sqlite as Sqlite
import Control.Applicative as A
import qualified Control.Exception as E
import Control.Monad (when)
import Control.Monad.IO.Unlift (MonadIO (..), MonadUnliftIO, withUnliftIO, unliftIO)
import Control.Monad.Logger (NoLoggingT, runNoLoggingT, MonadLogger)
import Control.Monad.Trans.Reader (ReaderT, runReaderT)
import UnliftIO.Resource (ResourceT, runResourceT)
import Control.Monad.Trans.Writer (runWriterT)
import Data.Acquire (Acquire, mkAcquire, with)
import Data.Aeson
import Data.Aeson.Types (modifyFailure)
import Data.Conduit
import qualified Data.Conduit.List as CL
import qualified Data.HashMap.Lazy as HashMap
import Data.Int (Int64)
import Data.IORef
import qualified Data.Map as Map
import Data.Monoid ((<>))
import Data.Pool (Pool)
import Data.Text (Text)
import qualified Data.Text as T
import qualified Data.Text.IO as TIO
import Lens.Micro.TH (makeLenses)
-- | Create a pool of SQLite connections.
--
-- Note that this should not be used with the @:memory:@ connection string, as
-- the pool will regularly remove connections, destroying your database.
-- Instead, use 'withSqliteConn'.
createSqlitePool :: (MonadLogger m, MonadUnliftIO m, IsSqlBackend backend)
=> Text -> Int -> m (Pool backend)
createSqlitePool = createSqlitePoolFromInfo . conStringToInfo
-- | Create a pool of SQLite connections.
--
-- Note that this should not be used with the @:memory:@ connection string, as
-- the pool will regularly remove connections, destroying your database.
-- Instead, use 'withSqliteConn'.
--
-- @since 2.6.2
createSqlitePoolFromInfo :: (MonadLogger m, MonadUnliftIO m, IsSqlBackend backend)
=> SqliteConnectionInfo -> Int -> m (Pool backend)
createSqlitePoolFromInfo connInfo = createSqlPool $ open' connInfo
-- | Run the given action with a connection pool.
--
-- Like 'createSqlitePool', this should not be used with @:memory:@.
withSqlitePool :: (MonadUnliftIO m, MonadLogger m, IsSqlBackend backend)
=> Text
-> Int -- ^ number of connections to open
-> (Pool backend -> m a) -> m a
withSqlitePool connInfo = withSqlPool . open' $ conStringToInfo connInfo
-- | Run the given action with a connection pool.
--
-- Like 'createSqlitePool', this should not be used with @:memory:@.
--
-- @since 2.6.2
withSqlitePoolInfo :: (MonadUnliftIO m, MonadLogger m, IsSqlBackend backend)
=> SqliteConnectionInfo
-> Int -- ^ number of connections to open
-> (Pool backend -> m a) -> m a
withSqlitePoolInfo connInfo = withSqlPool $ open' connInfo
withSqliteConn :: (MonadUnliftIO m, MonadLogger m, IsSqlBackend backend)
=> Text -> (backend -> m a) -> m a
withSqliteConn = withSqliteConnInfo . conStringToInfo
-- | @since 2.6.2
withSqliteConnInfo :: (MonadUnliftIO m, MonadLogger m, IsSqlBackend backend)
=> SqliteConnectionInfo -> (backend -> m a) -> m a
withSqliteConnInfo = withSqlConn . open'
open' :: (IsSqlBackend backend) => SqliteConnectionInfo -> LogFunc -> IO backend
open' connInfo logFunc = do
conn <- Sqlite.open $ _sqlConnectionStr connInfo
wrapConnectionInfo connInfo conn logFunc `E.onException` Sqlite.close conn
-- | Wrap up a raw 'Sqlite.Connection' as a Persistent SQL 'Connection'.
--
-- @since 1.1.5
wrapConnection :: (IsSqlBackend backend) => Sqlite.Connection -> LogFunc -> IO backend
wrapConnection = wrapConnectionInfo (mkSqliteConnectionInfo "")
-- | Wrap up a raw 'Sqlite.Connection' as a Persistent SQL
-- 'Connection', allowing full control over WAL and FK constraints.
--
-- @since 2.6.2
wrapConnectionInfo :: (IsSqlBackend backend)
=> SqliteConnectionInfo
-> Sqlite.Connection
-> LogFunc
-> IO backend
wrapConnectionInfo connInfo conn logFunc = do
when (_walEnabled connInfo) $ do
-- Turn on the write-ahead log
-- https://github.com/yesodweb/persistent/issues/363
turnOnWal <- Sqlite.prepare conn "PRAGMA journal_mode=WAL;"
_ <- Sqlite.stepConn conn turnOnWal
Sqlite.reset conn turnOnWal
Sqlite.finalize turnOnWal
when (_fkEnabled connInfo) $ do
-- Turn on foreign key constraints
-- https://github.com/yesodweb/persistent/issues/646
turnOnFK <- Sqlite.prepare conn "PRAGMA foreign_keys = on;"
_ <- Sqlite.stepConn conn turnOnFK
Sqlite.reset conn turnOnFK
Sqlite.finalize turnOnFK
smap <- newIORef $ Map.empty
return . mkPersistBackend $ SqlBackend
{ connPrepare = prepare' conn
, connStmtMap = smap
, connInsertSql = insertSql'
, connUpsertSql = Nothing
, connPutManySql = Nothing
, connInsertManySql = Nothing
, 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"
, connLogFunc = logFunc
, connMaxParams = Just 999
}
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 :: (MonadUnliftIO m, IsSqlBackend backend)
=> Text -- ^ connection string
-> ReaderT backend (NoLoggingT (ResourceT m)) a -- ^ database action
-> m a
runSqlite connstr = runResourceT
. runNoLoggingT
. withSqliteConn connstr
. runSqlConn
-- | 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 2.6.2
runSqliteInfo :: (MonadUnliftIO m, IsSqlBackend backend)
=> SqliteConnectionInfo
-> ReaderT backend (NoLoggingT (ResourceT m)) a -- ^ database action
-> m a
runSqliteInfo conInfo = runResourceT
. runNoLoggingT
. withSqliteConnInfo conInfo
. 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 -> [PersistValue] -> InsertSqlResult
insertSql' ent vals =
case entityPrimary ent of
Just _ ->
ISRManyKeys sql vals
where sql = T.concat
[ "INSERT INTO "
, escape $ entityDB ent
, "("
, T.intercalate "," $ map (escape . fieldDB) $ entityFields ent
, ") VALUES("
, T.intercalate "," (map (const "?") $ entityFields ent)
, ")"
]
Nothing ->
ISRInsertGet ins sel
where
sel = T.concat
[ "SELECT "
, escape $ fieldDB (entityId ent)
, " FROM "
, escape $ entityDB ent
, " WHERE _ROWID_=last_insert_rowid()"
]
ins = T.concat
[ "INSERT INTO "
, escape $ entityDB ent
, if null (entityFields ent)
then " VALUES(null)"
else T.concat
[ "("
, T.intercalate "," $ map (escape . fieldDB) $ entityFields ent
, ") VALUES("
, T.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.stepConn conn stmt
Sqlite.changes conn
withStmt'
:: MonadIO m
=> Sqlite.Connection
-> Sqlite.Statement
-> [PersistValue]
-> Acquire (ConduitM () [PersistValue] m ())
withStmt' conn stmt vals = do
_ <- mkAcquire
(Sqlite.bind stmt vals >> return stmt)
(Sqlite.reset conn)
return pull
where
pull = do
x <- liftIO $ Sqlite.stepConn conn 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) = T.concat [ "NUMERIC(", T.pack (show precision), ",", T.pack (show scale), ")" ]
showSqlType SqlDay = "DATE"
showSqlType SqlTime = "TIME"
showSqlType SqlDayTime = "TIMESTAMP"
showSqlType SqlBlob = "BLOB"
showSqlType SqlBool = "BOOLEAN"
showSqlType (SqlOther t) = t
migrate' :: [EntityDef]
-> (Text -> IO Statement)
-> EntityDef
-> 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' <- with (stmtQuery stmt [PersistText $ unDBName table])
(\src -> runConduit $ src .| 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
-- | Mock a migration even when the database is not present.
-- This function performs the same functionality of 'printMigration'
-- with the difference that an actual database isn't needed for it.
mockMigration :: Migration -> IO ()
mockMigration mig = do
smap <- newIORef $ Map.empty
let sqlbackend = SqlBackend
{ connPrepare = \_ -> do
return Statement
{ stmtFinalize = return ()
, stmtReset = return ()
, stmtExecute = undefined
, stmtQuery = \_ -> return $ return ()
}
, connStmtMap = smap
, connInsertSql = insertSql'
, connInsertManySql = Nothing
, connClose = undefined
, connMigrateSql = migrate'
, connBegin = helper "BEGIN"
, connCommit = helper "COMMIT"
, connRollback = ignoreExceptions . helper "ROLLBACK"
, connEscapeName = escape
, connNoLimit = "LIMIT -1"
, connRDBMS = "sqlite"
, connLimitOffset = decorateSQLWithLimitOffset "LIMIT -1"
, connLogFunc = undefined
, connUpsertSql = undefined
, connPutManySql = undefined
, connMaxParams = Just 999
}
result = runReaderT . runWriterT . runWriterT $ mig
resp <- result sqlbackend
mapM_ TIO.putStrLn $ map snd $ snd resp
where
helper t getter = do
stmt <- getter t
_ <- stmtExecute stmt []
stmtReset stmt
ignoreExceptions = E.handle (\(_ :: E.SomeException) -> return ())
-- | Check if a column name is listed as the "safe to remove" in the entity
-- list.
safeToRemove :: EntityDef -> DBName -> Bool
safeToRemove def (DBName colName)
= any (elem "SafeToRemove" . fieldAttrs)
$ filter ((== DBName colName) . fieldDB)
$ entityFields def
getCopyTable :: [EntityDef]
-> (Text -> IO Statement)
-> EntityDef
-> IO [(Bool, Text)]
getCopyTable allDefs getter def = do
stmt <- getter $ T.concat [ "PRAGMA table_info(", escape table, ")" ]
oldCols' <- with (stmtQuery stmt []) (\src -> runConduit $ src .| 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_ = fieldDB (entityId def)
return [ (False, tmpSql)
, (False, copyToTemp $ id_ : common)
, (common /= filter (not . safeToRemove def) oldCols, dropOld)
, (False, newSql)
, (False, copyToFinal $ id_ : newCols)
, (False, dropTmp)
]
where
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 <> "_backup"
(cols, uniqs, _) = mkColumns allDefs def
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 = T.concat
[ "INSERT INTO "
, escape tableTmp
, "("
, T.intercalate "," $ map escape common
, ") SELECT "
, T.intercalate "," $ map escape common
, " FROM "
, escape table
]
copyToFinal newCols = T.concat
[ "INSERT INTO "
, escape table
, " SELECT "
, T.intercalate "," $ map escape newCols
, " FROM "
, escape tableTmp
]
mkCreateTable :: Bool -> EntityDef -> ([Column], [UniqueDef]) -> Text
mkCreateTable isTemp entity (cols, uniqs) =
case entityPrimary entity of
Just pdef ->
T.concat
[ "CREATE"
, if isTemp then " TEMP" else ""
, " TABLE "
, escape $ entityDB entity
, "("
, T.drop 1 $ T.concat $ map (sqlColumn isTemp) cols
, ", PRIMARY KEY "
, "("
, T.intercalate "," $ map (escape . fieldDB) $ compositeFields pdef
, ")"
, ")"
]
Nothing -> T.concat
[ "CREATE"
, if isTemp then " TEMP" else ""
, " TABLE "
, escape $ entityDB entity
, "("
, escape $ fieldDB (entityId entity)
, " "
, showSqlType $ fieldSqlType $ entityId entity
," PRIMARY KEY"
, mayDefault $ defaultAttribute $ fieldAttrs $ entityId entity
, T.concat $ map (sqlColumn isTemp) cols
, T.concat $ map sqlUnique uniqs
, ")"
]
mayDefault :: Maybe Text -> Text
mayDefault def = case def of
Nothing -> ""
Just d -> " DEFAULT " <> d
sqlColumn :: Bool -> Column -> Text
sqlColumn noRef (Column name isNull typ def _cn _maxLen ref) = T.concat
[ ","
, escape name
, " "
, showSqlType typ
, if isNull then " NULL" else " NOT NULL"
, mayDefault def
, case ref of
Nothing -> ""
Just (table, _) -> if noRef then "" else " REFERENCES " <> 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 setup a connection pool.
data SqliteConf = SqliteConf
{ sqlDatabase :: Text
, sqlPoolSize :: Int
}
| SqliteConfInfo
{ sqlConnInfo :: SqliteConnectionInfo
, sqlPoolSize :: Int
} deriving Show
instance FromJSON SqliteConf where
parseJSON v = modifyFailure ("Persistent: error loading Sqlite conf: " ++) $ flip (withObject "SqliteConf") v parser where
parser o = if HashMap.member "database" o
then SqliteConf
A.<$> o .: "database"
A.<*> o .: "poolsize"
else SqliteConfInfo
A.<$> o .: "connInfo"
A.<*> o .: "poolsize"
instance PersistConfig SqliteConf where
type PersistConfigBackend SqliteConf = SqlPersistT
type PersistConfigPool SqliteConf = ConnectionPool
createPoolConfig (SqliteConf cs size) = runNoLoggingT $ createSqlitePoolFromInfo (conStringToInfo cs) size -- FIXME
createPoolConfig (SqliteConfInfo info size) = runNoLoggingT $ createSqlitePoolFromInfo info size -- FIXME
runPool _ = runSqlPool
loadConfig = parseJSON
finally :: MonadUnliftIO m
=> m a -- ^ computation to run first
-> m b -- ^ computation to run afterward (even if an exception was raised)
-> m a
finally a sequel = withUnliftIO $ \u ->
E.finally (unliftIO u a)
(unliftIO u sequel)
{-# INLINABLE finally #-}
-- | Creates a SqliteConnectionInfo from a connection string, with the
-- default settings.
--
-- @since 2.6.2
mkSqliteConnectionInfo :: Text -> SqliteConnectionInfo
mkSqliteConnectionInfo fp = SqliteConnectionInfo fp True True
-- | Parses connection options from a connection string. Used only to provide deprecated API.
conStringToInfo :: Text -> SqliteConnectionInfo
conStringToInfo connStr = SqliteConnectionInfo connStr' enableWal True where
(connStr', enableWal) = case () of
()
| Just cs <- T.stripPrefix "WAL=on " connStr -> (cs, True)
| Just cs <- T.stripPrefix "WAL=off " connStr -> (cs, False)
| otherwise -> (connStr, True)
-- | Information required to connect to a sqlite database. We export
-- lenses instead of fields to avoid being limited to the current
-- implementation.
--
-- @since 2.6.2
data SqliteConnectionInfo = SqliteConnectionInfo
{ _sqlConnectionStr :: Text -- ^ connection string for the database. Use @:memory:@ for an in-memory database.
, _walEnabled :: Bool -- ^ if the write-ahead log is enabled - see https://github.com/yesodweb/persistent/issues/363.
, _fkEnabled :: Bool -- ^ if foreign-key constraints are enabled.
} deriving Show
makeLenses ''SqliteConnectionInfo
instance FromJSON SqliteConnectionInfo where
parseJSON v = modifyFailure ("Persistent: error loading SqliteConnectionInfo: " ++) $
flip (withObject "SqliteConnectionInfo") v $ \o -> SqliteConnectionInfo
<$> o .: "connectionString"
<*> o .: "walEnabled"
<*> o .: "fkEnabled"