mysql-haskell-0.8.0.0: Database/MySQL/Connection.hs
{-|
Module : Database.MySQL.Connection
Description : Connection managment
Copyright : (c) Winterland, 2016
License : BSD
Maintainer : drkoster@qq.com
Stability : experimental
Portability : PORTABLE
This is an internal module, the 'MySQLConn' type should not directly acessed to user.
-}
module Database.MySQL.Connection where
import Control.Exception (Exception, bracketOnError,
throwIO)
import Control.Monad
import qualified Crypto.Hash as Crypto
import qualified Data.Binary.Put as Binary
import Data.Bits
import qualified Data.ByteArray as BA
import Data.ByteString (ByteString)
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString.Unsafe as B
import Data.IORef (IORef, newIORef, readIORef,
writeIORef)
import Data.Typeable
import Data.Word
import Database.MySQL.Protocol.Auth
import Database.MySQL.Protocol.Command
import Database.MySQL.Protocol.Packet
import Network.Socket (HostName, PortNumber)
import qualified Network.Socket as N
import System.IO.Streams (InputStream, OutputStream)
import qualified System.IO.Streams as Stream
import qualified System.IO.Streams.Binary as Binary
import qualified System.IO.Streams.TCP as TCP
--------------------------------------------------------------------------------
-- | 'MySQLConn' wrap both 'InputStream' and 'OutputStream' for MySQL 'Packet'.
--
-- You shouldn't use one 'MySQLConn' in different thread, if you do that,
-- consider protecting it with a @MVar@.
--
data MySQLConn = MySQLConn {
mysqlRead :: {-# UNPACK #-} !(InputStream Packet)
, mysqlWrite :: {-# UNPACK #-} !(OutputStream Packet)
, mysqlCloseSocket :: IO ()
, isConsumed :: {-# UNPACK #-} !(IORef Bool)
}
-- | Everything you need to establish a MySQL connection.
--
-- To setup a TLS connection, use module "Database.MySQL.TLS" or "Database.MySQL.OpenSSL".
--
data ConnectInfo = ConnectInfo
{ ciHost :: HostName
, ciPort :: PortNumber
, ciDatabase :: ByteString
, ciUser :: ByteString
, ciPassword :: ByteString
, ciCharset :: Word8
}
-- | A simple 'ConnectInfo' targeting localhost with @user=root@ and empty password.
--
-- Default charset is set to @utf8_general_ci@ to support older(< 5.5.3) MySQL versions,
-- but be aware this is a partial utf8 encoding, you may want to use 'defaultConnectInfoMB4'
-- instead to support full utf8 charset(emoji, etc.). You can query your server's support
-- with @SELECT id, collation_name FROM information_schema.collations ORDER BY id;@
--
defaultConnectInfo :: ConnectInfo
defaultConnectInfo = ConnectInfo "127.0.0.1" 3306 "" "root" "" utf8_general_ci
-- | 'defaultConnectInfo' with charset set to @utf8mb4_unicode_ci@
--
-- This is recommanded on any MySQL server version >= 5.5.3.
--
defaultConnectInfoMB4 :: ConnectInfo
defaultConnectInfoMB4 = ConnectInfo "127.0.0.1" 3306 "" "root" "" utf8mb4_unicode_ci
utf8_general_ci :: Word8
utf8_general_ci = 33
utf8mb4_unicode_ci :: Word8
utf8mb4_unicode_ci = 224
--------------------------------------------------------------------------------
-- | Socket buffer size.
--
-- maybe exposed to 'ConnectInfo' laster?
--
bUFSIZE :: Int
bUFSIZE = 16384
-- | Establish a MySQL connection.
--
connect :: ConnectInfo -> IO MySQLConn
connect = fmap snd . connectDetail
-- | Establish a MySQL connection with 'Greeting' back, so you can find server's version .etc.
--
connectDetail :: ConnectInfo -> IO (Greeting, MySQLConn)
connectDetail (ConnectInfo host port db user pass charset) =
bracketOnError (TCP.connectWithBufferSize host port bUFSIZE)
(\(_, _, sock) -> N.close sock) $ \ (is, os, sock) -> do
is' <- decodeInputStream is
os' <- Binary.encodeOutputStream os
p <- readPacket is'
greet <- decodeFromPacket p
let auth = mkAuth db user pass charset greet
Stream.write (Just (encodeToPacket 1 auth)) os'
q <- readPacket is'
if isOK q
then do
consumed <- newIORef True
let conn = MySQLConn is' os' (N.close sock) consumed
return (greet, conn)
else Stream.write Nothing os' >> decodeFromPacket q >>= throwIO . ERRException
mkAuth :: ByteString -> ByteString -> ByteString -> Word8 -> Greeting -> Auth
mkAuth db user pass charset greet =
let salt = greetingSalt1 greet `B.append` greetingSalt2 greet
scambleBuf = scramble salt pass
in Auth clientCap clientMaxPacketSize charset user scambleBuf db
where
scramble :: ByteString -> ByteString -> ByteString
scramble salt pass'
| B.null pass' = B.empty
| otherwise = B.pack (B.zipWith xor sha1pass withSalt)
where sha1pass = sha1 pass'
withSalt = sha1 (salt `B.append` sha1 sha1pass)
sha1 :: ByteString -> ByteString
sha1 = BA.convert . (Crypto.hash :: ByteString -> Crypto.Digest Crypto.SHA1)
-- | A specialized 'decodeInputStream' here for speed
decodeInputStream :: InputStream ByteString -> IO (InputStream Packet)
decodeInputStream is = Stream.makeInputStream $ do
bs <- Stream.readExactly 4 is
let len = fromIntegral (bs `B.unsafeIndex` 0)
.|. fromIntegral (bs `B.unsafeIndex` 1) `shiftL` 8
.|. fromIntegral (bs `B.unsafeIndex` 2) `shiftL` 16
seqN = bs `B.unsafeIndex` 3
body <- loopRead [] len is
return . Just $ Packet len seqN body
where
loopRead acc 0 _ = return $! L.fromChunks (reverse acc)
loopRead acc k is' = do
bs <- Stream.read is'
case bs of Nothing -> throwIO NetworkException
Just bs' -> do let l = fromIntegral (B.length bs')
if l >= k
then do
let (a, rest) = B.splitAt (fromIntegral k) bs'
unless (B.null rest) (Stream.unRead rest is')
return $! L.fromChunks (reverse (a:acc))
else do
let k' = k - l
k' `seq` loopRead (bs':acc) k' is'
-- | Close a MySQL connection.
--
close :: MySQLConn -> IO ()
close (MySQLConn _ os closeSocket _) = do
Stream.write Nothing os
closeSocket
-- | Send a 'COM_PING'.
--
ping :: MySQLConn -> IO OK
ping = flip command COM_PING
--------------------------------------------------------------------------------
-- helpers
-- | Send a 'Command' which don't return a resultSet.
--
command :: MySQLConn -> Command -> IO OK
command conn@(MySQLConn is os _ _) cmd = do
guardUnconsumed conn
writeCommand cmd os
waitCommandReply is
{-# INLINE command #-}
waitCommandReply :: InputStream Packet -> IO OK
waitCommandReply is = do
p <- readPacket is
if | isERR p -> decodeFromPacket p >>= throwIO . ERRException
| isOK p -> decodeFromPacket p
| otherwise -> throwIO (UnexpectedPacket p)
{-# INLINE waitCommandReply #-}
readPacket :: InputStream Packet -> IO Packet
readPacket is = Stream.read is >>= maybe
(throwIO NetworkException)
(\ p@(Packet len _ bs) -> if len < 16777215 then return p else go len [bs])
where
go len acc = Stream.read is >>= maybe
(throwIO NetworkException)
(\ (Packet len' seqN bs) -> do
let len'' = len + len'
acc' = bs:acc
if len' < 16777215
then return (Packet len'' seqN (L.concat . reverse $ acc'))
else len'' `seq` go len'' acc'
)
{-# INLINE readPacket #-}
writeCommand :: Command -> OutputStream Packet -> IO ()
writeCommand a os = let bs = Binary.runPut (putCommand a) in
go (fromIntegral (L.length bs)) 0 bs os
where
go len seqN bs os' = do
if len < 16777215
then Stream.write (Just (Packet len seqN bs)) os'
else do
let (bs', rest) = L.splitAt 16777215 bs
seqN' = seqN + 1
len' = len - 16777215
Stream.write (Just (Packet 16777215 seqN bs')) os'
seqN' `seq` len' `seq` go len' seqN' rest os'
{-# INLINE writeCommand #-}
guardUnconsumed :: MySQLConn -> IO ()
guardUnconsumed (MySQLConn _ _ _ consumed) = do
c <- readIORef consumed
unless c (throwIO UnconsumedResultSet)
{-# INLINE guardUnconsumed #-}
writeIORef' :: IORef a -> a -> IO ()
writeIORef' ref x = x `seq` writeIORef ref x
{-# INLINE writeIORef' #-}
--------------------------------------------------------------------------------
-- Exceptions
data NetworkException = NetworkException deriving (Typeable, Show)
instance Exception NetworkException
data UnconsumedResultSet = UnconsumedResultSet deriving (Typeable, Show)
instance Exception UnconsumedResultSet
data ERRException = ERRException ERR deriving (Typeable, Show)
instance Exception ERRException
data UnexpectedPacket = UnexpectedPacket Packet deriving (Typeable, Show)
instance Exception UnexpectedPacket