From cf9090219e88bebddd028294e831068f1da41949 Mon Sep 17 00:00:00 2001
From: Vincent Hanquez <vincent@snarc.org>
Date: Fri, 10 Apr 2015 08:29:49 +0100
Subject: [PATCH] initial array abstraction

---
 Crypto/Internal/WordArray.hs | 85 ++++++++++++++++++++++++++++++++++++
 cryptonite.cabal             |  1 +
 2 files changed, 86 insertions(+)
 create mode 100644 Crypto/Internal/WordArray.hs

diff --git a/Crypto/Internal/WordArray.hs b/Crypto/Internal/WordArray.hs
new file mode 100644
index 0000000..b393c2d
--- /dev/null
+++ b/Crypto/Internal/WordArray.hs
@@ -0,0 +1,85 @@
+-- |
+-- Module      : Crypto.Internal.Compat
+-- License     : BSD-style
+-- Maintainer  : Vincent Hanquez <vincent@snarc.org>
+-- Stability   : stable
+-- Portability : Good
+--
+-- Small and self contained array representation
+-- with limited safety for internal use.
+--
+-- the array produced should never be exposed to the user directly
+--
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE MagicHash #-}
+{-# LANGUAGE UnboxedTuples #-}
+module Crypto.Internal.WordArray
+    ( Array8
+    , Array32
+    , Array64
+    , array8
+    , array32
+    , array64
+    , arrayRead8
+    , arrayRead32
+    , arrayRead64
+    ) where
+
+import Data.Word
+import Crypto.Internal.Compat
+import GHC.Prim
+import GHC.Types
+import GHC.Word
+
+data Array8 = Array8 Addr#
+
+data Array32 = Array32 ByteArray#
+
+data Array64 = Array64 ByteArray#
+
+array8 :: Addr# -> Array8
+array8 = Array8
+
+array32 :: Int -> [Word32] -> Array32
+array32 (I# n) l = unsafeDoIO $ IO $ \s ->
+    case newAlignedPinnedByteArray# (n *# 4#) 4# s of
+        (# s', mbarr #) -> loop 0# s' mbarr l
+  where
+        loop _ st mb [] = freezeArray mb st
+        loop i st mb ((W32# x):xs)
+            | booleanPrim (i ==# 0#) = freezeArray mb st
+            | otherwise =
+                let st' = writeWord32Array# mb i x st
+                 in loop (i +# 1#) st' mb xs
+        freezeArray mb st =
+            case unsafeFreezeByteArray# mb st of
+                (# st', b #) -> (# st', Array32 b #)
+{-# NOINLINE array32 #-}
+
+array64 :: Int -> [Word64] -> Array64
+array64 (I# n) l = unsafeDoIO $ IO $ \s ->
+    case newAlignedPinnedByteArray# (n *# 8#) 8# s of
+        (# s', mbarr #) -> loop 0# s' mbarr l
+  where
+        loop _ st mb [] = freezeArray mb st
+        loop i st mb ((W64# x):xs)
+            | booleanPrim (i ==# 0#) = freezeArray mb st
+            | otherwise =
+                let st' = writeWord64Array# mb i x st
+                 in loop (i +# 1#) st' mb xs
+        freezeArray mb st =
+            case unsafeFreezeByteArray# mb st of
+                (# st', b #) -> (# st', Array64 b #)
+{-# NOINLINE array64 #-}
+
+arrayRead8 :: Array8 -> Int -> Word8
+arrayRead8 (Array8 a) (I# o) = W8# (indexWord8OffAddr# a o)
+{-# INLINE arrayRead8 #-}
+
+arrayRead32 :: Array32 -> Int -> Word32
+arrayRead32 (Array32 b) (I# o) = W32# (indexWord32Array# b o)
+{-# INLINE arrayRead32 #-}
+
+arrayRead64 :: Array64 -> Int -> Word64
+arrayRead64 (Array64 b) (I# o) = W64# (indexWord64Array# b o)
+{-# INLINE arrayRead64 #-}
diff --git a/cryptonite.cabal b/cryptonite.cabal
index 4471a48..0f64129 100644
--- a/cryptonite.cabal
+++ b/cryptonite.cabal
@@ -131,6 +131,7 @@ Library
                      Crypto.Internal.Imports
                      Crypto.Internal.Memory
                      Crypto.Internal.Words
+                     Crypto.Internal.WordArray
   Build-depends:     base >= 4.3 && < 5
                    , bytestring
                    , securemem >= 0.1.7