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-- |
-- Module : Crypto.Internal.ByteArray
-- License : BSD-style
-- Maintainer : Vincent Hanquez <vincent@snarc.org>
-- Stability : stable
-- Portability : Good
--
-- Simple and efficient byte array types
--
{-# LANGUAGE BangPatterns #-}
{-# OPTIONS_HADDOCK hide #-}
module Crypto.Internal.ByteArray
( module Data.ByteArray
, module Data.ByteArray.Mapping
, module Data.ByteArray.Encoding
, constAllZero
) where
import Data.ByteArray
import Data.ByteArray.Mapping
import Data.ByteArray.Encoding
import Data.Bits ((.|.))
import Data.Word (Word8)
import Foreign.Ptr (Ptr)
import Foreign.Storable (peekByteOff)
import Crypto.Internal.Compat (unsafeDoIO)
constAllZero :: ByteArrayAccess ba => ba -> Bool
constAllZero b = unsafeDoIO $ withByteArray b $ \p -> loop p 0 0
where
loop :: Ptr b -> Int -> Word8 -> IO Bool
loop p i !acc
| i == len = return $! acc == 0
| otherwise = do
e <- peekByteOff p i
loop p (i+1) (acc .|. e)
len = Data.ByteArray.length b
|
