From: Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
Date: Sun, 19 Jul 2015 06:33:23 +0000 (+0530)
Subject: helper function: havePiece
X-Git-Url: https://git.rkrishnan.org/about.html?a=commitdiff_plain;h=41186aba417948342c47148e33053b3e3d3f2bd6;p=functorrent.git

helper function: havePiece
---

diff --git a/src/FuncTorrent/Peer.hs b/src/FuncTorrent/Peer.hs
index e0a27c9..490f080 100644
--- a/src/FuncTorrent/Peer.hs
+++ b/src/FuncTorrent/Peer.hs
@@ -18,7 +18,7 @@ import Control.Monad (replicateM, liftM, forever)
 import Control.Applicative ((<$>), liftA3)
 import Data.Bits
 import Data.Word (Word8)
-import Data.Map (Map(..), fromList)
+import Data.Map (Map(..), fromList, (!))
 
 import FuncTorrent.Metainfo (Info(..), Metainfo(..))
 import FuncTorrent.Utils (splitN)
@@ -40,7 +40,7 @@ type Pieces = [PieceData]
 data PieceDlState = Pending
                   | InProgress
                   | Have
-                  deriving (Show)
+                  deriving (Show, Eq)
 
 -- 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
@@ -69,13 +69,17 @@ data PeerMsg = KeepAliveMsg
 
 -- 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 :: Integer -> ByteString -> PieceMap
 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
 
+havePiece :: PieceMap -> Integer -> Bool
+havePiece pm index =
+  state (pm ! index) == Have
+
 genHandShakeMsg :: ByteString -> String -> ByteString
 genHandShakeMsg infoHash peer_id = concat [pstrlen, pstr, reserved, infoHash, peerID]
   where pstrlen = singleton 19