import Data.ByteString (ByteString, unpack, concat, hGet, hPut, take, empty)
import qualified Data.ByteString.Char8 as BC (length)
import Network (connectTo, PortID(..))
-import Control.Monad (liftM, forM)
+import Control.Monad.State
import Data.Bits
import Data.Word (Word8)
import Data.Map (Map, fromList, toList, (!), mapWithKey, adjust)
import FuncTorrent.Fileops (createDummyFile, writeFileAtOffset)
import FuncTorrent.PeerMsgs (Peer(..), PeerMsg(..), sendMsg, getMsg, genHandshakeMsg)
--- PeerState is a misnomer
-data PeerState = PeerState { handle :: Handle
- , peer :: Peer
- , meChoking :: Bool
- , meInterested :: Bool
- , heChoking :: Bool
- , heInterested :: Bool}
+data PState = PState { handle :: Handle
+ , peer :: Peer
+ , meChoking :: Bool
+ , meInterested :: Bool
+ , heChoking :: Bool
+ , heInterested :: Bool}
+
+type PeerState = State PState
data PieceDlState = Pending
| InProgress
-- 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 :: PieceDlState -- ^ state of the piece from download perspective.
+ , dlstate :: PieceDlState -- ^ state of the piece from download perspective.
, hash :: ByteString -- ^ piece hash
, len :: Integer } -- ^ piece length
mkPieceMap :: Integer -> ByteString -> [Integer] -> PieceMap
mkPieceMap numPieces pieceHash pLengths = fromList kvs
where kvs = [(i, PieceData { peers = []
- , state = Pending
+ , dlstate = Pending
, hash = h
, len = pLen })
| (i, h, pLen) <- zip3 [0..numPieces] hashes pLengths]
havePiece :: PieceMap -> Integer -> Bool
havePiece pm index =
- state (pm ! index) == Have
+ dlstate (pm ! index) == Have
connectToPeer :: Peer -> IO Handle
connectToPeer (Peer _ ip port) = do
in
setBits ++ go bs' (pos + 1)
--- recvMsg :: Peer -> Handle -> Msg
-msgLoop :: PeerState -> PieceMap -> IO ()
-msgLoop pState@(PeerState { meInterested = False, heChoking = True }) pieceStatus =
- do
- -- if me NOT Interested and she is Choking, tell her that
- -- I am interested.
- let h = handle pState
- sendMsg h InterestedMsg
- putStrLn $ "--> InterestedMsg to peer: " ++ show (peer pState)
- msgLoop (pState { meInterested = True }) pieceStatus
-msgLoop pState@(PeerState { meInterested = True, heChoking = False }) pieceStatus =
- -- if me Interested and she not Choking, send her a request
- -- for a piece.
- case pickPiece pieceStatus of
- Nothing -> putStrLn "Nothing to download"
- Just workPiece -> do
- let pLen = len (pieceStatus ! workPiece)
- putStrLn $ "piece length = " ++ show pLen
- pBS <- downloadPiece (handle pState) workPiece pLen
- if not $ verifyHash pBS (hash (pieceStatus ! workPiece))
- then
- putStrLn $ "Hash mismatch: " ++ show (hash (pieceStatus ! workPiece)) ++ " vs " ++ show (take 20 (SHA1.hash pBS))
- else do
- let fileOffset = if workPiece == 0 then 0 else workPiece * len (pieceStatus ! (workPiece - 1))
- putStrLn $ "Write into file at offset: " ++ show fileOffset
- writeFileAtOffset "/tmp/download.file" fileOffset pBS
- msgLoop pState (adjust (\pieceData -> pieceData { state = Have }) workPiece pieceStatus)
-msgLoop pState pieceStatus = do
- msg <- getMsg (handle pState)
- putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer pState)
- case msg of
- KeepAliveMsg -> do
- sendMsg (handle pState) KeepAliveMsg
- putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show (peer pState)
- msgLoop pState pieceStatus
- BitFieldMsg bss -> do
- let pieceList = bitfieldToList (unpack bss)
- pieceStatus' = updatePieceAvailability pieceStatus (peer pState) pieceList
- putStrLn $ show (length pieceList) ++ " Pieces"
- -- for each pieceIndex in pieceList, make an entry in the pieceStatus
- -- map with pieceIndex as the key and modify the value to add the peer.
- -- download each of the piece in order
- msgLoop pState pieceStatus'
- UnChokeMsg ->
- msgLoop (pState { heChoking = False }) pieceStatus
- _ ->
- msgLoop pState pieceStatus
+-- helper functions to manipulate PeerState
+toPeerState :: Handle
+ -> Peer
+ -> Bool -- ^ meChoking
+ -> Bool -- ^ meInterested
+ -> Bool -- ^ heChoking
+ -> Bool -- ^ heInterested
+ -> PState
+toPeerState h p meCh meIn heCh heIn =
+ PState { handle = h
+ , peer = p
+ , heChoking = heCh
+ , heInterested = heIn
+ , meChoking = meCh
+ , meInterested = meIn }
-- simple algorithm to pick piece.
-- pick the first piece from 0 that is not downloaded yet.
pickPiece :: PieceMap -> Maybe Integer
pickPiece m =
let pieceList = toList m
- allPending = filter (\(_, v) -> state v == Pending) pieceList
+ allPending = filter (\(_, v) -> dlstate v == Pending) pieceList
in
case allPending of
[] -> Nothing
handlePeerMsgs p m peerId = do
h <- connectToPeer p
doHandshake h p (infoHash m) peerId
- let state = PeerState { handle = h
- , peer = p
- , heInterested = False
- , heChoking = True
- , meInterested = False
- , meChoking = True }
+ let pstate = toPeerState h p False True False True
pieceHash = pieces (info m)
numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
pLen = pieceLength (info m)
fileLen = lengthInBytes (info m)
+ fileName = name (info m)
pieceStatus = mkPieceMap numPieces pieceHash (splitNum fileLen pLen)
- createDummyFile "/tmp/download.file" (fromIntegral fileLen)
- msgLoop state pieceStatus
-
+ createDummyFile fileName (fromIntegral fileLen)
+ (r, _) <- runStateT (msgLoop pieceStatus fileName) pstate
+ return ()
+
+msgLoop :: PieceMap -> FilePath -> StateT PState IO ()
+msgLoop pieceStatus file = do
+ h <- gets handle
+ st <- get
+ case st of
+ PState { meInterested = False, heChoking = True } -> do
+ liftIO $ sendMsg h InterestedMsg
+ gets peer >>= (\p -> liftIO $ putStrLn $ "--> InterestedMsg to peer: " ++ show p)
+ modify (\st -> st { meInterested = True })
+ msgLoop pieceStatus file
+ PState { meInterested = True, heChoking = False } -> do
+ case pickPiece pieceStatus of
+ Nothing -> liftIO $ putStrLn "Nothing to download"
+ Just workPiece -> do
+ let pLen = len (pieceStatus ! workPiece)
+ liftIO $ putStrLn $ "piece length = " ++ show pLen
+ pBS <- liftIO $ downloadPiece h workPiece pLen
+ if not $ verifyHash pBS (hash (pieceStatus ! workPiece))
+ then
+ liftIO $ putStrLn $ "Hash mismatch: " ++ show (hash (pieceStatus ! workPiece)) ++ " vs " ++ show (take 20 (SHA1.hash pBS))
+ else do
+ let fileOffset = if workPiece == 0 then 0 else workPiece * len (pieceStatus ! (workPiece - 1))
+ liftIO $ putStrLn $ "Write into file at offset: " ++ show fileOffset
+ liftIO $ writeFileAtOffset file fileOffset pBS
+ msgLoop (adjust (\pieceData -> pieceData { dlstate = Have }) workPiece pieceStatus) file
+ _ -> do
+ msg <- liftIO $ getMsg h
+ gets peer >>= (\p -> liftIO $ putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show p)
+ case msg of
+ KeepAliveMsg -> do
+ liftIO $ sendMsg h KeepAliveMsg
+ gets peer >>= (\p -> liftIO $ putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show p)
+ msgLoop pieceStatus file
+ BitFieldMsg bss -> do
+ p <- gets peer
+ let pieceList = bitfieldToList (unpack bss)
+ pieceStatus' = updatePieceAvailability pieceStatus p pieceList
+ liftIO $ putStrLn $ show (length pieceList) ++ " Pieces"
+ -- for each pieceIndex in pieceList, make an entry in the pieceStatus
+ -- map with pieceIndex as the key and modify the value to add the peer.
+ -- download each of the piece in order
+ msgLoop pieceStatus' file
+ UnChokeMsg -> do
+ modify (\st -> st {heChoking = False })
+ msgLoop pieceStatus file
+
+
downloadPiece :: Handle -> Integer -> Integer -> IO ByteString
downloadPiece h index pieceLength = do
let chunks = splitNum pieceLength 16384
projects / functorrent.git / blobdiff