module Database.Persist.MySQL
( withMySQLPool
, withMySQLConn
, createMySQLPool
, module Database.Persist.Sql
, MySQL.ConnectInfo(..)
, MySQLBase.SSLInfo(..)
, MySQL.defaultConnectInfo
, MySQLBase.defaultSSLInfo
, MySQLConf(..)
) where
import Control.Arrow
import Control.Monad (mzero)
import Control.Monad.Logger (MonadLogger, runNoLoggingT)
import Control.Monad.IO.Class (MonadIO (..))
import Control.Monad.Trans.Class (lift)
import Control.Monad.Trans.Error (ErrorT(..))
import Data.Aeson
import Data.ByteString (ByteString)
import Data.Either (partitionEithers)
import Data.Fixed (Pico)
import Data.Function (on)
import Data.IORef
import Data.List (find, intercalate, sort, groupBy)
import Data.Text (Text, pack)
import System.Environment (getEnvironment)
import Data.Acquire (Acquire, mkAcquire, with)
import Data.Conduit
import qualified Blaze.ByteString.Builder.Char8 as BBB
import qualified Blaze.ByteString.Builder.ByteString as BBS
import qualified Data.Conduit.List as CL
import qualified Data.Map as Map
import qualified Data.Text as T
import qualified Data.Text.Encoding as T
import Database.Persist.Sql
import Data.Int (Int64)
import qualified Database.MySQL.Simple as MySQL
import qualified Database.MySQL.Simple.Param as MySQL
import qualified Database.MySQL.Simple.Result as MySQL
import qualified Database.MySQL.Simple.Types as MySQL
import qualified Database.MySQL.Base as MySQLBase
import qualified Database.MySQL.Base.Types as MySQLBase
import Control.Monad.Trans.Control (MonadBaseControl)
import Control.Monad.Trans.Resource (MonadResource, runResourceT)
withMySQLPool :: (MonadIO m, MonadLogger m, MonadBaseControl IO m) =>
MySQL.ConnectInfo
-> Int
-> (ConnectionPool -> m a)
-> m a
withMySQLPool ci = withSqlPool $ open' ci
createMySQLPool :: (MonadBaseControl IO m, MonadIO m, MonadLogger m) =>
MySQL.ConnectInfo
-> Int
-> m ConnectionPool
createMySQLPool ci = createSqlPool $ open' ci
withMySQLConn :: (MonadBaseControl IO m, MonadIO m, MonadLogger m) =>
MySQL.ConnectInfo
-> (Connection -> m a)
-> m a
withMySQLConn = withSqlConn . open'
open' :: MySQL.ConnectInfo -> LogFunc -> IO Connection
open' ci logFunc = do
conn <- MySQL.connect ci
MySQLBase.autocommit conn False
smap <- newIORef $ Map.empty
return SqlBackend
{ connPrepare = prepare' conn
, connStmtMap = smap
, connInsertSql = insertSql'
, connClose = MySQL.close conn
, connMigrateSql = migrate' ci
, connBegin = const $ MySQL.execute_ conn "start transaction" >> return ()
, connCommit = const $ MySQL.commit conn
, connRollback = const $ MySQL.rollback conn
, connEscapeName = pack . escapeDBName
, connNoLimit = "LIMIT 18446744073709551615"
, connRDBMS = "mysql"
, connLimitOffset = decorateSQLWithLimitOffset "LIMIT 18446744073709551615"
, connLogFunc = logFunc
}
prepare' :: MySQL.Connection -> Text -> IO Statement
prepare' conn sql = do
let query = MySQL.Query (T.encodeUtf8 sql)
return Statement
{ stmtFinalize = return ()
, stmtReset = return ()
, stmtExecute = execute' conn query
, stmtQuery = withStmt' conn query
}
insertSql' :: EntityDef -> [PersistValue] -> InsertSqlResult
insertSql' ent vals =
let sql = pack $ concat
[ "INSERT INTO "
, escapeDBName $ entityDB ent
, "("
, intercalate "," $ map (escapeDBName . fieldDB) $ entityFields ent
, ") VALUES("
, intercalate "," (map (const "?") $ entityFields ent)
, ")"
]
in case entityPrimary ent of
Just _ -> ISRManyKeys sql vals
Nothing -> ISRInsertGet sql "SELECT LAST_INSERT_ID()"
execute' :: MySQL.Connection -> MySQL.Query -> [PersistValue] -> IO Int64
execute' conn query vals = MySQL.execute conn query (map P vals)
withStmt' :: MonadIO m
=> MySQL.Connection
-> MySQL.Query
-> [PersistValue]
-> Acquire (Source m [PersistValue])
withStmt' conn query vals = do
result <- mkAcquire createResult MySQLBase.freeResult
return $ fetchRows result >>= CL.sourceList
where
createResult = do
formatted <- MySQL.formatQuery conn query (map P vals)
MySQLBase.query conn formatted
MySQLBase.storeResult conn
fetchRows result = liftIO $ do
fields <- MySQLBase.fetchFields result
let getters = [ maybe PersistNull (getGetter (MySQLBase.fieldType f) f . Just) | f <- fields]
convert = use getters
where use (g:gs) (col:cols) =
let v = g col
vs = use gs cols
in v `seq` vs `seq` (v:vs)
use _ _ = []
let go acc = do
row <- MySQLBase.fetchRow result
case row of
[] -> return (acc [])
_ -> let converted = convert row
in converted `seq` go (acc . (converted:))
go id
newtype P = P PersistValue
instance MySQL.Param P where
render (P (PersistText t)) = MySQL.render t
render (P (PersistByteString bs)) = MySQL.render bs
render (P (PersistInt64 i)) = MySQL.render i
render (P (PersistDouble d)) = MySQL.render d
render (P (PersistBool b)) = MySQL.render b
render (P (PersistDay d)) = MySQL.render d
render (P (PersistTimeOfDay t)) = MySQL.render t
render (P (PersistUTCTime t)) = MySQL.render t
render (P PersistNull) = MySQL.render MySQL.Null
render (P (PersistList l)) = MySQL.render $ listToJSON l
render (P (PersistMap m)) = MySQL.render $ mapToJSON m
render (P (PersistRational r)) =
MySQL.Plain $ BBB.fromString $ show (fromRational r :: Pico)
render (P (PersistDbSpecific s)) = MySQL.Plain $ BBS.fromByteString s
render (P (PersistObjectId _)) =
error "Refusing to serialize a PersistObjectId to a MySQL value"
type Getter a = MySQLBase.Field -> Maybe ByteString -> a
convertPV :: MySQL.Result a => (a -> b) -> Getter b
convertPV f = (f .) . MySQL.convert
getGetter :: MySQLBase.Type -> Getter PersistValue
getGetter MySQLBase.Tiny = convertPV PersistBool
getGetter MySQLBase.Int24 = convertPV PersistInt64
getGetter MySQLBase.Short = convertPV PersistInt64
getGetter MySQLBase.Long = convertPV PersistInt64
getGetter MySQLBase.LongLong = convertPV PersistInt64
getGetter MySQLBase.Float = convertPV PersistDouble
getGetter MySQLBase.Double = convertPV PersistDouble
getGetter MySQLBase.Decimal = convertPV PersistDouble
getGetter MySQLBase.NewDecimal = convertPV PersistDouble
getGetter MySQLBase.VarChar = convertPV PersistByteString
getGetter MySQLBase.VarString = convertPV PersistByteString
getGetter MySQLBase.String = convertPV PersistByteString
getGetter MySQLBase.Blob = convertPV PersistByteString
getGetter MySQLBase.TinyBlob = convertPV PersistByteString
getGetter MySQLBase.MediumBlob = convertPV PersistByteString
getGetter MySQLBase.LongBlob = convertPV PersistByteString
getGetter MySQLBase.Time = convertPV PersistTimeOfDay
getGetter MySQLBase.DateTime = convertPV PersistUTCTime
getGetter MySQLBase.Timestamp = convertPV PersistUTCTime
getGetter MySQLBase.Date = convertPV PersistDay
getGetter MySQLBase.NewDate = convertPV PersistDay
getGetter MySQLBase.Year = convertPV PersistDay
getGetter MySQLBase.Null = \_ _ -> PersistNull
getGetter MySQLBase.Set = convertPV PersistText
getGetter MySQLBase.Enum = convertPV PersistText
getGetter MySQLBase.Geometry = \_ m ->
case m of
Just g -> PersistDbSpecific g
Nothing -> error "Unexpected null in database specific value"
getGetter other = error $ "MySQL.getGetter: type " ++
show other ++ " not supported."
migrate' :: MySQL.ConnectInfo
-> [EntityDef]
-> (Text -> IO Statement)
-> EntityDef
-> IO (Either [Text] [(Bool, Text)])
migrate' connectInfo allDefs getter val = do
let name = entityDB val
(idClmn, old) <- getColumns connectInfo getter val
let (newcols, udefs, fdefs) = mkColumns allDefs val
let udspair = map udToPair udefs
case (idClmn, old, partitionEithers old) of
([], [], _) -> do
let idtxt = case entityPrimary val of
Just pdef -> concat [" PRIMARY KEY (", intercalate "," $ map (escapeDBName . fieldDB) $ compositeFields pdef, ")"]
Nothing -> concat [escapeDBName $ fieldDB $ entityId val, " BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY"]
let addTable = AddTable $ concat
[ "CREATe TABLE "
, escapeDBName name
, "("
, idtxt
, if null newcols then [] else ","
, intercalate "," $ map showColumn newcols
, ")"
]
let uniques = flip concatMap udspair $ \(uname, ucols) ->
[ AlterTable name $
AddUniqueConstraint uname $
map (findTypeOfColumn allDefs name) ucols ]
let foreigns = do
Column { cName=cname, cReference=Just (refTblName, a) } <- newcols
return $ AlterColumn name (refTblName, addReference allDefs (refName name cname) refTblName cname)
let foreignsAlt = map (\fdef -> let (childfields, parentfields) = unzip (map (\((_,b),(_,d)) -> (b,d)) (foreignFields fdef))
in AlterColumn name (foreignRefTableDBName fdef, AddReference (foreignRefTableDBName fdef) (foreignConstraintNameDBName fdef) childfields parentfields)) fdefs
return $ Right $ map showAlterDb $ addTable : uniques ++ foreigns ++ foreignsAlt
(_, _, ([], old')) -> do
let excludeForeignKeys (xs,ys) = (map (\c -> case cReference c of
Just (_,fk) -> case find (\f -> fk == foreignConstraintNameDBName f) fdefs of
Just _ -> c { cReference = Nothing }
Nothing -> c
Nothing -> c) xs,ys)
(acs, ats) = getAlters allDefs name (newcols, udspair) $ excludeForeignKeys $ partitionEithers old'
acs' = map (AlterColumn name) acs
ats' = map (AlterTable name) ats
return $ Right $ map showAlterDb $ acs' ++ ats'
(_, _, (errs, _)) -> return $ Left errs
findTypeOfColumn :: [EntityDef] -> DBName -> DBName -> (DBName, FieldType)
findTypeOfColumn allDefs name col =
maybe (error $ "Could not find type of column " ++
show col ++ " on table " ++ show name ++
" (allDefs = " ++ show allDefs ++ ")")
((,) col) $ do
entDef <- find ((== name) . entityDB) allDefs
fieldDef <- find ((== col) . fieldDB) (entityFields entDef)
return (fieldType fieldDef)
addReference :: [EntityDef] -> DBName -> DBName -> DBName -> AlterColumn
addReference allDefs fkeyname reftable cname = AddReference reftable fkeyname [cname] [id_]
where
id_ = maybe (error $ "Could not find ID of entity " ++ show reftable
++ " (allDefs = " ++ show allDefs ++ ")")
id $ do
entDef <- find ((== reftable) . entityDB) allDefs
return (fieldDB $ entityId entDef)
data AlterColumn = Change Column
| Add' Column
| Drop
| Default String
| NoDefault
| Update' String
| AddReference DBName DBName [DBName] [DBName]
| DropReference DBName
type AlterColumn' = (DBName, AlterColumn)
data AlterTable = AddUniqueConstraint DBName [(DBName, FieldType)]
| DropUniqueConstraint DBName
data AlterDB = AddTable String
| AlterColumn DBName AlterColumn'
| AlterTable DBName AlterTable
udToPair :: UniqueDef -> (DBName, [DBName])
udToPair ud = (uniqueDBName ud, map snd $ uniqueFields ud)
getColumns :: MySQL.ConnectInfo
-> (Text -> IO Statement)
-> EntityDef
-> IO ( [Either Text (Either Column (DBName, [DBName]))]
, [Either Text (Either Column (DBName, [DBName]))]
)
getColumns connectInfo getter def = do
stmtIdClmn <- getter "SELECT COLUMN_NAME, \
\IS_NULLABLE, \
\DATA_TYPE, \
\COLUMN_DEFAULT \
\FROM INFORMATION_SCHEMA.COLUMNS \
\WHERE TABLE_SCHEMA = ? \
\AND TABLE_NAME = ? \
\AND COLUMN_NAME = ?"
inter1 <- with (stmtQuery stmtIdClmn vals) ($$ CL.consume)
ids <- runResourceT $ CL.sourceList inter1 $$ helperClmns
stmtClmns <- getter "SELECT COLUMN_NAME, \
\IS_NULLABLE, \
\COLUMN_TYPE, \
\COLUMN_DEFAULT \
\FROM INFORMATION_SCHEMA.COLUMNS \
\WHERE TABLE_SCHEMA = ? \
\AND TABLE_NAME = ? \
\AND COLUMN_NAME <> ?"
inter2 <- with (stmtQuery stmtClmns vals) ($$ CL.consume)
cs <- runResourceT $ CL.sourceList inter2 $$ helperClmns
stmtCntrs <- getter "SELECT CONSTRAINT_NAME, \
\COLUMN_NAME \
\FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE \
\WHERE TABLE_SCHEMA = ? \
\AND TABLE_NAME = ? \
\AND COLUMN_NAME <> ? \
\AND CONSTRAINT_NAME <> 'PRIMARY' \
\AND REFERENCED_TABLE_SCHEMA IS NULL \
\ORDER BY CONSTRAINT_NAME, \
\COLUMN_NAME"
us <- with (stmtQuery stmtCntrs vals) ($$ helperCntrs)
return (ids, cs ++ us)
where
vals = [ PersistText $ pack $ MySQL.connectDatabase connectInfo
, PersistText $ unDBName $ entityDB def
, PersistText $ unDBName $ fieldDB $ entityId def ]
helperClmns = CL.mapM getIt =$ CL.consume
where
getIt = fmap (either Left (Right . Left)) .
liftIO .
getColumn connectInfo getter (entityDB def)
helperCntrs = do
let check [ PersistByteString cntrName
, PersistByteString clmnName] = return ( T.decodeUtf8 cntrName
, T.decodeUtf8 clmnName )
check other = fail $ "helperCntrs: unexpected " ++ show other
rows <- mapM check =<< CL.consume
return $ map (Right . Right . (DBName . fst . head &&& map (DBName . snd)))
$ groupBy ((==) `on` fst) rows
getColumn :: MySQL.ConnectInfo
-> (Text -> IO Statement)
-> DBName
-> [PersistValue]
-> IO (Either Text Column)
getColumn connectInfo getter tname [ PersistByteString cname
, PersistByteString null_
, PersistByteString type'
, default'] =
fmap (either (Left . pack) Right) $
runErrorT $ do
default_ <- case default' of
PersistNull -> return Nothing
PersistText t -> return (Just t)
PersistByteString bs ->
case T.decodeUtf8' bs of
Left exc -> fail $ "Invalid default column: " ++
show default' ++ " (error: " ++
show exc ++ ")"
Right t -> return (Just t)
_ -> fail $ "Invalid default column: " ++ show default'
stmt <- lift $ getter "SELECT REFERENCED_TABLE_NAME, \
\CONSTRAINT_NAME, \
\ORDINAL_POSITION \
\FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE \
\WHERE TABLE_SCHEMA = ? \
\AND TABLE_NAME = ? \
\AND COLUMN_NAME = ? \
\AND REFERENCED_TABLE_SCHEMA = ? \
\ORDER BY CONSTRAINT_NAME, \
\COLUMN_NAME"
let vars = [ PersistText $ pack $ MySQL.connectDatabase connectInfo
, PersistText $ unDBName $ tname
, PersistByteString cname
, PersistText $ pack $ MySQL.connectDatabase connectInfo ]
cntrs <- with (stmtQuery stmt vars) ($$ CL.consume)
ref <- case cntrs of
[] -> return Nothing
[[PersistByteString tab, PersistByteString ref, PersistInt64 pos]] ->
return $ if pos == 1 then Just (DBName $ T.decodeUtf8 tab, DBName $ T.decodeUtf8 ref) else Nothing
_ -> fail "MySQL.getColumn/getRef: never here"
return Column
{ cName = DBName $ T.decodeUtf8 cname
, cNull = null_ == "YES"
, cSqlType = parseType type'
, cDefault = default_
, cDefaultConstraintName = Nothing
, cMaxLen = Nothing
, cReference = ref
}
getColumn _ _ _ x =
return $ Left $ pack $ "Invalid result from INFORMATION_SCHEMA: " ++ show x
parseType :: ByteString -> SqlType
parseType "bigint(20)" = SqlInt64
parseType "decimal(32,20)" = SqlNumeric 32 20
parseType b = SqlOther $ T.decodeUtf8 b
getAlters :: [EntityDef]
-> DBName
-> ([Column], [(DBName, [DBName])])
-> ([Column], [(DBName, [DBName])])
-> ([AlterColumn'], [AlterTable])
getAlters allDefs tblName (c1, u1) (c2, u2) =
(getAltersC c1 c2, getAltersU u1 u2)
where
getAltersC [] old = concatMap dropColumn old
getAltersC (new:news) old =
let (alters, old') = findAlters tblName allDefs new old
in alters ++ getAltersC news old'
dropColumn col =
map ((,) (cName col)) $
[DropReference n | Just (_, n) <- [cReference col]] ++
[Drop]
getAltersU [] old = map (DropUniqueConstraint . fst) old
getAltersU ((name, cols):news) old =
case lookup name old of
Nothing ->
AddUniqueConstraint name (map findType cols) : getAltersU news old
Just ocols ->
let old' = filter (\(x, _) -> x /= name) old
in if sort cols == ocols
then getAltersU news old'
else DropUniqueConstraint name
: AddUniqueConstraint name (map findType cols)
: getAltersU news old'
where
findType = findTypeOfColumn allDefs tblName
findAlters :: DBName -> [EntityDef] -> Column -> [Column] -> ([AlterColumn'], [Column])
findAlters tblName allDefs col@(Column name isNull type_ def defConstraintName maxLen ref) cols =
case filter ((name ==) . cName) cols of
[] -> case ref of
Nothing -> ([(name, Add' col)],[])
Just (tname, b) -> let cnstr = [addReference allDefs (refName tblName name) tname name]
in (map ((,) tname) (Add' col : cnstr), cols)
Column _ isNull' type_' def' defConstraintName' maxLen' ref':_ ->
let
refDrop = case (ref == ref', ref') of
(False, Just (_, cname)) -> [(name, DropReference cname)]
_ -> []
refAdd = case (ref == ref', ref) of
(False, Just (tname, cname)) -> [(tname, addReference allDefs (refName tblName name) tname name)]
_ -> []
modType | showSqlType type_ maxLen False `ciEquals` showSqlType type_' maxLen' False && isNull == isNull' = []
| otherwise = [(name, Change col)]
modDef | def == def' = []
| otherwise = case def of
Nothing -> [(name, NoDefault)]
Just s -> [(name, Default $ T.unpack s)]
in ( refDrop ++ modType ++ modDef ++ refAdd
, filter ((name /=) . cName) cols )
where
ciEquals x y = T.toCaseFold (T.pack x) == T.toCaseFold (T.pack y)
showColumn :: Column -> String
showColumn (Column n nu t def defConstraintName maxLen ref) = concat
[ escapeDBName n
, " "
, showSqlType t maxLen True
, " "
, if nu then "NULL" else "NOT NULL"
, case def of
Nothing -> ""
Just s -> " DEFAULT " ++ T.unpack s
, case ref of
Nothing -> ""
Just (s, _) -> " REFERENCES " ++ escapeDBName s
]
showSqlType :: SqlType
-> Maybe Integer
-> Bool
-> String
showSqlType SqlBlob Nothing _ = "BLOB"
showSqlType SqlBlob (Just i) _ = "VARBINARY(" ++ show i ++ ")"
showSqlType SqlBool _ _ = "TINYINT(1)"
showSqlType SqlDay _ _ = "DATE"
showSqlType SqlDayTime _ _ = "DATETIME"
showSqlType SqlInt32 _ _ = "INT(11)"
showSqlType SqlInt64 _ _ = "BIGINT"
showSqlType SqlReal _ _ = "DOUBLE"
showSqlType (SqlNumeric s prec) _ _ = "NUMERIC(" ++ show s ++ "," ++ show prec ++ ")"
showSqlType SqlString Nothing True = "TEXT CHARACTER SET utf8"
showSqlType SqlString Nothing False = "TEXT"
showSqlType SqlString (Just i) True = "VARCHAR(" ++ show i ++ ") CHARACTER SET utf8"
showSqlType SqlString (Just i) False = "VARCHAR(" ++ show i ++ ")"
showSqlType SqlTime _ _ = "TIME"
showSqlType (SqlOther t) _ _ = T.unpack t
showAlterDb :: AlterDB -> (Bool, Text)
showAlterDb (AddTable s) = (False, pack s)
showAlterDb (AlterColumn t (c, ac)) =
(isUnsafe ac, pack $ showAlter t (c, ac))
where
isUnsafe Drop = True
isUnsafe _ = False
showAlterDb (AlterTable t at) = (False, pack $ showAlterTable t at)
showAlterTable :: DBName -> AlterTable -> String
showAlterTable table (AddUniqueConstraint cname cols) = concat
[ "ALTER TABLE "
, escapeDBName table
, " ADD CONSTRAINT "
, escapeDBName cname
, " UNIQUE("
, intercalate "," $ map escapeDBName' cols
, ")"
]
where
escapeDBName' (name, (FTTypeCon _ "Text" )) = escapeDBName name ++ "(200)"
escapeDBName' (name, (FTTypeCon _ "String" )) = escapeDBName name ++ "(200)"
escapeDBName' (name, (FTTypeCon _ "ByteString")) = escapeDBName name ++ "(200)"
escapeDBName' (name, _ ) = escapeDBName name
showAlterTable table (DropUniqueConstraint cname) = concat
[ "ALTER TABLE "
, escapeDBName table
, " DROP INDEX "
, escapeDBName cname
]
showAlter :: DBName -> AlterColumn' -> String
showAlter table (oldName, Change (Column n nu t def defConstraintName maxLen _ref)) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " CHANGE "
, escapeDBName oldName
, " "
, showColumn (Column n nu t def defConstraintName maxLen Nothing)
]
showAlter table (_, Add' col) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " ADD COLUMN "
, showColumn col
]
showAlter table (n, Drop) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " DROP COLUMN "
, escapeDBName n
]
showAlter table (n, Default s) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " ALTER COLUMN "
, escapeDBName n
, " SET DEFAULT "
, s
]
showAlter table (n, NoDefault) =
concat
[ "ALTER TABLE "
, escapeDBName table
, " ALTER COLUMN "
, escapeDBName n
, " DROP DEFAULT"
]
showAlter table (n, Update' s) =
concat
[ "UPDATE "
, escapeDBName table
, " SET "
, escapeDBName n
, "="
, s
, " WHERE "
, escapeDBName n
, " IS NULL"
]
showAlter table (_, AddReference reftable fkeyname t2 id2) = concat
[ "ALTER TABLE "
, escapeDBName table
, " ADD CONSTRAINT "
, escapeDBName fkeyname
, " FOREIGN KEY("
, intercalate "," $ map escapeDBName t2
, ") REFERENCES "
, escapeDBName reftable
, "("
, intercalate "," $ map escapeDBName id2
, ")"
]
showAlter table (_, DropReference cname) = concat
[ "ALTER TABLE "
, escapeDBName table
, " DROP FOREIGN KEY "
, escapeDBName cname
]
refName :: DBName -> DBName -> DBName
refName (DBName table) (DBName column) =
DBName $ T.concat [table, "_", column, "_fkey"]
escapeDBName :: DBName -> String
escapeDBName (DBName s) = '`' : go (T.unpack s)
where
go ('`':xs) = '`' : '`' : go xs
go ( x :xs) = x : go xs
go "" = "`"
data MySQLConf = MySQLConf
{ myConnInfo :: MySQL.ConnectInfo
, myPoolSize :: Int
}
instance PersistConfig MySQLConf where
type PersistConfigBackend MySQLConf = SqlPersistT
type PersistConfigPool MySQLConf = ConnectionPool
createPoolConfig (MySQLConf cs size) = runNoLoggingT $ createMySQLPool cs size
runPool _ = runSqlPool
loadConfig (Object o) = do
database <- o .: "database"
host <- o .: "host"
port <- o .: "port"
path <- o .:? "path"
user <- o .: "user"
password <- o .: "password"
pool <- o .: "poolsize"
let ci = MySQL.defaultConnectInfo
{ MySQL.connectHost = host
, MySQL.connectPort = port
, MySQL.connectPath = case path of
Just p -> p
Nothing -> MySQL.connectPath MySQL.defaultConnectInfo
, MySQL.connectUser = user
, MySQL.connectPassword = password
, MySQL.connectDatabase = database
}
return $ MySQLConf ci pool
loadConfig _ = mzero
applyEnv conf = do
env <- getEnvironment
let maybeEnv old var = maybe old id $ lookup ("MYSQL_" ++ var) env
return conf
{ myConnInfo =
case myConnInfo conf of
MySQL.ConnectInfo
{ MySQL.connectHost = host
, MySQL.connectPort = port
, MySQL.connectPath = path
, MySQL.connectUser = user
, MySQL.connectPassword = password
, MySQL.connectDatabase = database
} -> (myConnInfo conf)
{ MySQL.connectHost = maybeEnv host "HOST"
, MySQL.connectPort = read $ maybeEnv (show port) "PORT"
, MySQL.connectPath = maybeEnv path "PATH"
, MySQL.connectUser = maybeEnv user "USER"
, MySQL.connectPassword = maybeEnv password "PASSWORD"
, MySQL.connectDatabase = maybeEnv database "DATABASE"
}
}