gistfile1.hs

{-# LANGUAGE BangPatterns #-}
module Main where

import qualified Data.ByteString as BS
import System.IO
import Control.Monad
import Data.Bits
import Data.Word
import Data.Monoid

import Data.ByteString.Lazy.Builder  -- requires bytestring-0.10.x

bs = BS.replicate 64 0

builder = mconcat (replicate 1000000 (byteString bs))

buildPL = mconcat (replicate 64 (word8 0))
{-# INLINE buildPL #-}

buildMAC :: Word64 -> Builder
buildMAC i = word16BE (fromIntegral $ i `shiftR` 32) <> word32BE (fromIntegral $ i .&. 0xFFFFFFFF)
{-# INLINE buildMAC #-}

buildEth :: (Word64,Word64) -> Builder
buildEth (i,j) = mconcat [ buildMAC i, buildMAC j, word32BE 0, word16BE 0 -- Ethernet Frame header
                       , word32BE 0, word32BE 0, word32BE 0, word32BE 0 -- IP Header
                       , word32BE 0, word32BE 0, word32BE 0, word32BE 0 -- TCP Header
                       , byteString bs                                  -- Payload
                       , word32BE 0                                     -- CRC32
                       ]
{-# INLINE buildEth #-}


buildEth2 :: (Word64,Word64) -> Builder
buildEth2 (i,j) = mconcat [ buildMAC i, buildMAC j, word32BE 0, word16BE 0 -- Ethernet Frame header
                          , lazyByteString ipHeader                        -- IP Header
                          , lazyByteString tcpHeader                       -- TCP Header
                          , byteString bs                                  -- Payload
                          , word32BE 0                                     -- CRC32
                          ]
  where ipHeader  = toLazyByteString  $ mconcat [word32BE 0, word32BE 0, word32BE 0, word32BE 0]
        tcpHeader = toLazyByteString  $ mconcat [word32BE 0, word32BE 0, word32BE 0, word32BE 0]
{-# INLINE buildEth2 #-}

buildAll = mconcat (map buildEth2 [(i,j)|i <- [1..1000], j <- [1..1000]])
{-# INLINE buildAll #-}

main = do
  hPutBuilder stdout buildAll