From cea45102e2d746ad6576007d5caa7b792caed310 Mon Sep 17 00:00:00 2001
From: Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
Date: Sun, 19 Jul 2015 11:46:25 +0530
Subject: [PATCH] add piece hash into the pieceMap

---
 src/FuncTorrent/Peer.hs | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/FuncTorrent/Peer.hs b/src/FuncTorrent/Peer.hs
index d7197eb..e0a27c9 100644
--- a/src/FuncTorrent/Peer.hs
+++ b/src/FuncTorrent/Peer.hs
@@ -18,9 +18,11 @@ import Control.Monad (replicateM, liftM, forever)
 import Control.Applicative ((<$>), liftA3)
 import Data.Bits
 import Data.Word (Word8)
-import Data.Map (Map(..))
+import Data.Map (Map(..), fromList)
 
 import FuncTorrent.Metainfo (Info(..), Metainfo(..))
+import FuncTorrent.Utils (splitN)
+
 type ID = String
 type IP = String
 type Port = Integer
@@ -35,14 +37,15 @@ data PeerState = PeerState { handle :: Handle
 -- should probably be a TVar.
 type Pieces = [PieceData]
 
-data PieceState = Pending
-                | InProgress
-                | Have
-                deriving (Show)
+data PieceDlState = Pending
+                  | InProgress
+                  | Have
+                  deriving (Show)
 
 -- todo - map with index to a new data structure (peers who have that piece amd state)
 data PieceData = PieceData { peers :: [Peer]        -- ^ list of peers who have this piece
-                           , state :: PieceState }  -- ^ state of the piece from download perspective.
+                           , state :: PieceDlState  -- ^ state of the piece from download perspective.
+                           , hash  :: ByteString }      -- ^ piece hash
 
 -- which piece is with which peers
 type PieceMap = Map Integer PieceData
@@ -64,6 +67,15 @@ data PeerMsg = KeepAliveMsg
              | PortMsg Port
              deriving (Show)
 
+-- Make the initial Piece map, with the assumption that no peer has the
+-- piece and that every piece is pending download.
+mkPieceMap :: Integer -> ByteString -> Map Integer PieceData
+mkPieceMap numPieces pieceHash = fromList kvs
+  where kvs = [(i, PieceData { peers = []
+                             , state = Pending
+                             , hash = h }) | (i, h) <- zip [0..numPieces] hashes]
+        hashes = splitN (fromIntegral numPieces) pieceHash
+
 genHandShakeMsg :: ByteString -> String -> ByteString
 genHandShakeMsg infoHash peer_id = concat [pstrlen, pstr, reserved, infoHash, peerID]
   where pstrlen = singleton 19
@@ -172,6 +184,7 @@ createDummyFile path size = do
 msgLoop :: Handle -> ByteString -> IO ()
 msgLoop h pieceHash =
   let numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
+      pieceStatus = mkPieceMap numPieces pieceHash
   in
    forever $ do
      msg <- getMsg h
-- 
2.37.2