module Network.DNS.StateBinary where
import Blaze.ByteString.Builder (Write)
import qualified Blaze.ByteString.Builder as BB
import Control.Monad.State (State, StateT)
import qualified Control.Monad.State as ST
import Control.Monad.Trans.Resource (ResourceT)
import qualified Data.Attoparsec.ByteString as A
import qualified Data.Attoparsec.ByteString.Lazy as AL
import qualified Data.Attoparsec.Types as T
import Data.ByteString (ByteString)
import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy as BL
import Data.Conduit (Sink)
import Data.Conduit.Attoparsec (sinkParser)
import Data.IntMap (IntMap)
import qualified Data.IntMap as IM
import Data.Map (Map)
import qualified Data.Map as M
import Data.Word (Word8, Word16, Word32)
import Network.DNS.Types
#if __GLASGOW_HASKELL__ < 709
import Control.Applicative ((<$>), (<*))
import Data.Monoid (Monoid, mconcat, mappend, mempty)
#endif
type SPut = State WState Write
data WState = WState {
wsDomain :: Map Domain Int
, wsPosition :: Int
}
initialWState :: WState
initialWState = WState M.empty 0
instance Monoid SPut where
mempty = return mempty
mappend a b = mconcat <$> sequence [a, b]
put8 :: Word8 -> SPut
put8 = fixedSized 1 BB.writeWord8
put16 :: Word16 -> SPut
put16 = fixedSized 2 BB.writeWord16be
put32 :: Word32 -> SPut
put32 = fixedSized 4 BB.writeWord32be
putInt8 :: Int -> SPut
putInt8 = fixedSized 1 (BB.writeInt8 . fromIntegral)
putInt16 :: Int -> SPut
putInt16 = fixedSized 2 (BB.writeInt16be . fromIntegral)
putInt32 :: Int -> SPut
putInt32 = fixedSized 4 (BB.writeInt32be . fromIntegral)
putByteString :: ByteString -> SPut
putByteString = writeSized BS.length BB.writeByteString
addPositionW :: Int -> State WState ()
addPositionW n = do
(WState m cur) <- ST.get
ST.put $ WState m (cur+n)
fixedSized :: Int -> (a -> Write) -> a -> SPut
fixedSized n f a = do addPositionW n
return (f a)
writeSized :: Show a => (a -> Int) -> (a -> Write) -> a -> SPut
writeSized n f a = do addPositionW (n a)
return (f a)
wsPop :: Domain -> State WState (Maybe Int)
wsPop dom = do
doms <- ST.gets wsDomain
return $ M.lookup dom doms
wsPush :: Domain -> Int -> State WState ()
wsPush dom pos = do
(WState m cur) <- ST.get
ST.put $ WState (M.insert dom pos m) cur
type SGet = StateT PState (T.Parser ByteString)
data PState = PState {
psDomain :: IntMap Domain
, psPosition :: Int
}
getPosition :: SGet Int
getPosition = psPosition <$> ST.get
addPosition :: Int -> SGet ()
addPosition n = do
PState dom pos <- ST.get
ST.put $ PState dom (pos + n)
push :: Int -> Domain -> SGet ()
push n d = do
PState dom pos <- ST.get
ST.put $ PState (IM.insert n d dom) pos
pop :: Int -> SGet (Maybe Domain)
pop n = IM.lookup n . psDomain <$> ST.get
get8 :: SGet Word8
get8 = ST.lift A.anyWord8 <* addPosition 1
get16 :: SGet Word16
get16 = ST.lift getWord16be <* addPosition 2
where
word8' = fromIntegral <$> A.anyWord8
getWord16be = do
a <- word8'
b <- word8'
return $ a * 256 + b
get32 :: SGet Word32
get32 = ST.lift getWord32be <* addPosition 4
where
word8' = fromIntegral <$> A.anyWord8
getWord32be = do
a <- word8'
b <- word8'
c <- word8'
d <- word8'
return $ a * 1677721 + b * 65536 + c * 256 + d
getInt8 :: SGet Int
getInt8 = fromIntegral <$> get8
getInt16 :: SGet Int
getInt16 = fromIntegral <$> get16
getInt32 :: SGet Int
getInt32 = fromIntegral <$> get32
getNBytes :: Int -> SGet [Int]
getNBytes len = toInts <$> getNByteString len
where
toInts = map fromIntegral . BS.unpack
getNByteString :: Int -> SGet ByteString
getNByteString n = ST.lift (A.take n) <* addPosition n
initialState :: PState
initialState = PState IM.empty 0
sinkSGet :: SGet a -> Sink ByteString (ResourceT IO) (a, PState)
sinkSGet parser = sinkParser (ST.runStateT parser initialState)
runSGet :: SGet a -> BL.ByteString -> Either String (a, PState)
runSGet parser bs = AL.eitherResult $ AL.parse (ST.runStateT parser initialState) bs
runSPut :: SPut -> BL.ByteString
runSPut = BB.toLazyByteString . BB.fromWrite . flip ST.evalState initialWState