[Haskell-cafe] haskell crypto is reaaaaaaaaaally slow

[Anatoly Yakovenko]

i don't think its a problem with bytestrings.  I strictly unpacked the
bytestring and i still have 4 seconds for an md5 sum of the [word8]


On 6/19/07, Donald Bruce Stewart <dons at cse.unsw.edu.au> wrote:
> > > aeyakovenko:
> > > > $ time ./md5sum ./md5sum
> > > > [105,252,52,138,187,192,216,17,225,123,185,3,124,101,86,132]
> > > >
> > > > real    0m4.790s
> > > > user    0m3.688s
> > > > sys     0m0.492s
> > > >
> > > > $ time md5sum ./md5sum
> > > > 69fc348abbc0d811e17bb9037c655684  ./md5sum
> > > >
> > > > real    0m0.023s
> > > > user    0m0.000s
> > > > sys     0m0.008s
> > > >
>
> I wasn't happy with the hex printing loop. Here's a shorter version.
>
>
>     {-# OPTIONS -O2 -fffi #-}
>     --
>     -- ghc MD5.hs -o hsmd5 -lcrypto
>     --
>
>     import System.Environment
>     import qualified Data.ByteString.Base as B (unsafeUseAsCStringLen)
>     import qualified Data.ByteString      as B
>     import Foreign
>     import Foreign.C.Types
>     import Numeric
>     import Text.Printf
>     import Control.Monad
>
>     main = do
>         (f:_)  <- getArgs
>         src    <- B.readFile f
>         printf "MD5 (%s) = %s \n" f (md5sum src)
>
>     -- Fast md5 using OpenSSL and non-copying bytestrings
>     md5sum :: B.ByteString -> String
>     md5sum p = unsafePerformIO $ B.unsafeUseAsCStringLen p $ \(ptr,n) -> do
>         digest  <- c_md5 ptr (fromIntegral n) nullPtr
>         liftM concat $ forM [0..15] $ \n -> do
>                             w <- peekElemOff digest n
>                             return $ case showHex w [] of [x] -> ['0', x]; x -> x
>
>     -- unsigned char *MD5(const unsigned char *d, unsigned long n, unsigned char *md);
>     foreign import ccall "openssl/md5.h MD5" c_md5
>         :: Ptr CChar -> CULong -> Ptr CChar -> IO (Ptr Word8)
>
>
> ByteStrings were designed for this zero-copy passing of big data to C,
> by the way, so its a perfect fit.
>
> -- Don
>