zip-stream/Codec/Archive/Zip/Conduit/Internal.hs
2017-05-11 21:38:16 -04:00

26 lines
787 B
Haskell

module Codec.Archive.Zip.Conduit.Internal
( zipError
, sizeCRC
) where
import Control.Monad.Catch (MonadThrow, throwM)
import qualified Data.ByteString as BS
import qualified Data.Conduit as C
import Data.Digest.CRC32 (crc32Update)
import Data.Word (Word32)
import Codec.Archive.Zip.Conduit.Types
zipError :: MonadThrow m => String -> m a
zipError = throwM . ZipError
passthroughFold :: Monad m => (a -> b -> a) -> a -> C.ConduitM b b m a
passthroughFold f z = C.await >>= maybe
(return z)
(\x -> do
C.yield x
passthroughFold f (f z x))
sizeCRC :: (Monad m, Integral n) => C.ConduitM BS.ByteString BS.ByteString m (n, Word32)
sizeCRC = passthroughFold (\(l, c) b -> (l + fromIntegral (BS.length b), crc32Update c b)) (0, 0)