[Haskell-cafe] Seven ways to store 16 bytes

6 Jan 2010

      In preparing the speed ups in uuid-0.1.2, I investigated various ways to store 16 bytes of data in a Haskell object.  Surprisingly, storing as 4 Word32 values in a standard data type worked best for that application.

I've extracted out the testing work for that and put it here:
	http://bitbucket.org/mtnviewmark/haskell-playground/src/tip/16bytes/

There you can find the code that tests storing 16 bytes in various ways:
...
import qualified Data.Array         as A
import qualified Data.Array.Unboxed as U
import qualified Data.Array.Vector  as V
import qualified Data.ByteString    as B
data InBytes = BY !Word8 !Word8 !Word8 !Word8 !Word8 !Word8 !Word8 !Word8
                  !Word8 !Word8 !Word8 !Word8 !Word8 !Word8 !Word8 !Word8
    deriving (Eq, Ord)
data InWords = WO !Word32 !Word32 !Word32 !Word32
    deriving (Eq, Ord)
data InList       = LI [Word8]              deriving (Eq, Ord)
data InByteString = BS B.ByteString         deriving (Eq, Ord)
data InArray      = AR (A.Array Int Word8)  deriving (Eq, Ord)
data InUArray     = UA (U.UArray Int Word8) deriving (Eq, Ord)
data InVector     = VE (V.UArr Word8)       deriving (Eq)
Depending on operations will be needed most, different storage methods do best.

Enjoy!

	- Mark 

Mark Lentczner (MtnViewMark)
http://www.ozonehouse.com/mark/