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module ByteStringUtil where
import Data.ByteString.Lazy.Internal
import Data.ByteString.Lazy as L
import qualified Data.ByteString as S
import System.IO
import System.IO.Unsafe
oneMeg :: Int
oneMeg = 1048576
hGetContentsN :: Int -> Handle -> IO ByteString
hGetContentsN kk h = lazyRead
where
k = kk - chunkOverhead
lazyRead = unsafeInterleaveIO loop
loop = do
c <- S.hGetSome h k -- only blocks if there is no data available
if S.null c
then hClose h >> return Empty
else do cs <- lazyRead
return (Chunk c cs)
readBigFile :: FilePath -> IO ByteString
readBigFile fname = do
h <- openFile fname ReadMode
hGetContentsN oneMeg h
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