From 7163e8027574d2a02e1f852a84d9252c51ade573 Mon Sep 17 00:00:00 2001
From: Alberto Ruiz <aruiz@um.es>
Date: Wed, 18 Jun 2014 07:41:31 +0200
Subject: to/from ByteString

---
 packages/base/src/Data/Packed/Matrix.hs          | 16 ++++------
 packages/base/src/Data/Packed/Vector.hs          | 40 +++++++++++++++++++++---
 packages/base/src/Numeric/LinearAlgebra/Devel.hs |  7 +++--
 3 files changed, 46 insertions(+), 17 deletions(-)

(limited to 'packages/base/src')

diff --git a/packages/base/src/Data/Packed/Matrix.hs b/packages/base/src/Data/Packed/Matrix.hs
index 2420c94..6445ce4 100644
--- a/packages/base/src/Data/Packed/Matrix.hs
+++ b/packages/base/src/Data/Packed/Matrix.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE CPP #-}
 
@@ -53,20 +54,15 @@ import Control.Monad(liftM)
 #ifdef BINARY
 
 import Data.Binary
-import Control.Monad(replicateM)
 
-instance (Binary a, Element a, Storable a) => Binary (Matrix a) where
+instance (Binary (Vector a), Element a) => Binary (Matrix a) where
     put m = do
-            let r = rows m
-            let c = cols m
-            put r
-            put c
-            mapM_ (\i -> mapM_ (\j -> put $ m @@> (i,j)) [0..(c-1)]) [0..(r-1)]
+            put (cols m)
+            put (flatten m)
     get = do
-          r <- get
           c <- get
-          xs <- replicateM r $ replicateM c get
-          return $ fromLists xs
+          v <- get
+          return (reshape c v)
 
 #endif
 
diff --git a/packages/base/src/Data/Packed/Vector.hs b/packages/base/src/Data/Packed/Vector.hs
index 31dcf47..2104f52 100644
--- a/packages/base/src/Data/Packed/Vector.hs
+++ b/packages/base/src/Data/Packed/Vector.hs
@@ -22,7 +22,8 @@ module Data.Packed.Vector (
     subVector, takesV, vjoin, join,
     mapVector, mapVectorWithIndex, zipVector, zipVectorWith, unzipVector, unzipVectorWith,
     mapVectorM, mapVectorM_, mapVectorWithIndexM, mapVectorWithIndexM_,
-    foldLoop, foldVector, foldVectorG, foldVectorWithIndex
+    foldLoop, foldVector, foldVectorG, foldVectorWithIndex,
+    toByteString, fromByteString
 ) where
 
 import Data.Packed.Internal.Vector
@@ -35,6 +36,12 @@ import Foreign.Storable
 import Data.Binary
 import Control.Monad(replicateM)
 
+import Data.ByteString.Internal as BS
+import Foreign.ForeignPtr(castForeignPtr)
+import Data.Vector.Storable.Internal(updPtr)
+import Foreign.Ptr(plusPtr)
+
+
 -- a 64K cache, with a Double taking 13 bytes in Bytestring,
 -- implies a chunk size of 5041
 chunk :: Int
@@ -43,28 +50,51 @@ chunk = 5000
 chunks :: Int -> [Int]
 chunks d = let c = d `div` chunk
                m = d `mod` chunk
-           in if m /= 0 then reverse (m:(replicate c chunk)) else (replicate c chunk)  
+           in if m /= 0 then reverse (m:(replicate c chunk)) else (replicate c chunk)
 
-putVector v = do
-              let d = dim v
-              mapM_ (\i -> put $ v @> i) [0..(d-1)]
+putVector v = mapM_ put $! toList v
 
 getVector d = do
               xs <- replicateM d get
               return $! fromList xs
 
+--------------------------------------------------------------------------------
+
+toByteString :: Storable t => Vector t -> ByteString
+toByteString v = BS.PS (castForeignPtr fp) (sz*o) (sz * dim v)
+  where
+    (fp,o,_n) = unsafeToForeignPtr v
+    sz = sizeOf (v@>0)
+
+
+fromByteString :: Storable t => ByteString -> Vector t
+fromByteString (BS.PS fp o n) = r
+  where
+    r = unsafeFromForeignPtr (castForeignPtr (updPtr (`plusPtr` o) fp)) 0 n'
+    n' = n `div` sz
+    sz = sizeOf (r@>0)
+
+--------------------------------------------------------------------------------
+
 instance (Binary a, Storable a) => Binary (Vector a) where
+
     put v = do
             let d = dim v
             put d
             mapM_ putVector $! takesV (chunks d) v
+
+    -- put = put . v2bs
+
     get = do
           d <- get
           vs <- mapM getVector $ chunks d
           return $! vjoin vs
 
+    -- get = fmap bs2v get
+
 #endif
 
+
 -------------------------------------------------------------------
 
 {- | creates a Vector of the specified length using the supplied function to
diff --git a/packages/base/src/Numeric/LinearAlgebra/Devel.hs b/packages/base/src/Numeric/LinearAlgebra/Devel.hs
index fce8b71..55894e0 100644
--- a/packages/base/src/Numeric/LinearAlgebra/Devel.hs
+++ b/packages/base/src/Numeric/LinearAlgebra/Devel.hs
@@ -49,9 +49,12 @@ module Numeric.LinearAlgebra.Devel(
     mapMatrixWithIndex, mapMatrixWithIndexM, mapMatrixWithIndexM_,
     liftMatrix, liftMatrix2, liftMatrix2Auto,
 
-    -- * Misc
+    -- * Sparse representation
     CSR(..), fromCSR, mkCSR,
-    GMatrix(..)
+    GMatrix(..),
+
+    -- * Misc
+    toByteString, fromByteString
 
 ) where
 
-- 
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