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{-# LANGUAGE CPP, ForeignFunctionInterface #-}
#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
{-# LANGUAGE Trustworthy #-}
#endif
module Data.Hashable.RandomSource
(
getRandomBytes
, getRandomBytes_
) where
import Data.ByteString as B
import Data.ByteString.Internal (create)
import Foreign.C.Error (throwErrnoIfMinus1_)
#if MIN_VERSION_base(4,5,0)
import Foreign.C.Types (CInt(CInt))
#else
import Foreign.C.Types (CInt)
#endif
import Foreign.Ptr (Ptr)
getRandomBytes :: Int -> IO ByteString
getRandomBytes nbytes
| nbytes <= 0 = return B.empty
| otherwise = create nbytes $ flip (getRandomBytes_ "getRandomBytes") nbytes
getRandomBytes_ :: String -> Ptr a -> Int -> IO ()
getRandomBytes_ what ptr nbytes = do
throwErrnoIfMinus1_ what $ c_getRandomBytes ptr (fromIntegral nbytes)
foreign import ccall unsafe "hashable_getRandomBytes" c_getRandomBytes
:: Ptr a -> CInt -> IO CInt
|
