refactor the piecemap initialization

[functorrent.git] / src / FuncTorrent / Peer.hs

diff --git a/src/FuncTorrent/Peer.hs b/src/FuncTorrent/Peer.hs
index 61b5112c7811d43e765a4d59e01bb8d68e546999..157dab0c021e7d5155169fdc638f200c29b48a3d 100644 (file)
--- a/src/FuncTorrent/Peer.hs
+++ b/src/FuncTorrent/Peer.hs
@@ -1,8 +1,11 @@
 {-# LANGUAGE OverloadedStrings #-}
 module FuncTorrent.Peer
     (Peer(..),
+     PieceMap,
      handlePeerMsgs,
-     bytesDownloaded
+     bytesDownloaded,
+     initPieceMap,
+     pieceMapFromFile
     ) where
 
 import Prelude hiding (lookup, concat, replicate, splitAt, take, filter)
@@ -14,13 +17,12 @@ import Network (connectTo, PortID(..))
 import Control.Monad.State
 import Data.Bits
 import Data.Word (Word8)
-import Data.Map (Map, fromList, toList, (!), mapWithKey, adjust, filter)
+import Data.Map (Map, fromList, toList, (!), mapWithKey, traverseWithKey, adjust, filter)
 import qualified Crypto.Hash.SHA1 as SHA1 (hash)
 import Safe (headMay)
 
 import FuncTorrent.Metainfo (Info(..), Metainfo(..))
-import FuncTorrent.Utils (splitN, splitNum)
-import FuncTorrent.Fileops (createDummyFile, writeFileAtOffset)
+import FuncTorrent.Utils (splitN, splitNum, writeFileAtOffset, readFileAtOffset)
 import FuncTorrent.PeerMsgs (Peer(..), PeerMsg(..), sendMsg, getMsg, genHandshakeMsg)
 
 data PState = PState { handle :: Handle
@@ -61,6 +63,17 @@ initPieceMap pieceHash fileLen pieceLen = fromList kvs
     hashes = splitN 20 pieceHash
     pLengths = (splitNum fileLen pieceLen)
 
+pieceMapFromFile :: FilePath -> PieceMap -> IO PieceMap
+pieceMapFromFile filePath pieceMap = do
+  traverseWithKey f pieceMap
+    where
+      f k v = do
+        let offset = if k == 0 then 0 else k * len (pieceMap ! (k - 1))
+        isHashValid <- (flip verifyHash) (hash v) <$> (readFileAtOffset filePath offset (len v))
+        if isHashValid
+          then return $ v { dlstate = Have }
+          else return $ v
+
 havePiece :: PieceMap -> Integer -> Bool
 havePiece pm index =
   dlstate (pm ! index) == Have
@@ -120,18 +133,13 @@ updatePieceAvailability pieceStatus p pieceList =
                        then (pd { peers = p : peers pd })
                        else pd) pieceStatus
 
-handlePeerMsgs :: Peer -> String -> Metainfo -> IO ()
-handlePeerMsgs p peerId m = do
+handlePeerMsgs :: Peer -> String -> Metainfo -> PieceMap -> IO ()
+handlePeerMsgs p peerId m pieceMap = do
   h <- connectToPeer p
   doHandshake h p (infoHash m) peerId
   let pstate = toPeerState h p False False True True
-      pieceHash = pieces (info m)
-      pLen = pieceLength (info m)
-      fileLen = lengthInBytes (info m)
-      fileName = name (info m)
-      pieceStatus = initPieceMap pieceHash fileLen pLen
-  createDummyFile fileName (fromIntegral fileLen)
-  _ <- runStateT (msgLoop pieceStatus fileName) pstate
+      filePath = name (info m)
+  _ <- runStateT (msgLoop pieceMap filePath) pstate
   return ()
 
 msgLoop :: PieceMap -> FilePath -> StateT PState IO ()