{-# LANGUAGE OverloadedStrings #-}
module FuncTorrent.Peer
(Peer(..),
- handShake
+ handlePeerMsgs
) where
-import Prelude hiding (lookup, concat, replicate, splitAt)
+import Prelude hiding (lookup, concat, replicate, splitAt, writeFile)
-import System.IO
-import Data.ByteString (ByteString, pack, unpack, concat, hGet, hPut, singleton, append)
-import Data.ByteString.Lazy (fromStrict)
-import qualified Data.ByteString.Char8 as BC (replicate, pack, readInt)
+import System.IO (Handle, BufferMode(..), hSetBuffering)
+import Data.ByteString (ByteString, pack, unpack, concat, hGet, hPut, singleton, writeFile)
+import Data.ByteString.Lazy (fromStrict, fromChunks, toStrict)
+import qualified Data.ByteString.Char8 as BC (replicate, pack, length)
import Network (connectTo, PortID(..))
-import Data.Binary (Binary(..), decode)
+import Data.Binary (Binary(..), decode, encode)
import Data.Binary.Put (putWord32be, putWord16be, putWord8)
-import Data.Binary.Get (getWord32be, getWord16be, getWord8)
-import Control.Monad (replicateM, liftM)
+import Data.Binary.Get (getWord32be, getWord16be, getWord8, runGet)
+import Control.Monad (replicateM, liftM, forever)
import Control.Applicative ((<$>), liftA3)
+import Data.Bits
+import Data.Word (Word8)
+import Data.Map (Map(..), fromList, toList, (!), mapWithKey)
+
+import FuncTorrent.Metainfo (Info(..), Metainfo(..))
+import FuncTorrent.Utils (splitN)
type ID = String
type IP = String
type Port = Integer
+-- PeerState is a misnomer
data PeerState = PeerState { handle :: Handle
- , am_choking :: Bool
- , am_interested :: Bool
- , peer_choking :: Bool
- , peer_interested :: Bool}
+ , peer :: Peer
+ , meChoking :: Bool
+ , meInterested :: Bool
+ , heChoking :: Bool
+ , heInterested :: Bool}
-- Maintain info on every piece and the current state of it.
-- should probably be a TVar.
type Pieces = [PieceData]
-data PieceState = Pending
- | InProgress
- | Have
- deriving (Show)
+data PieceDlState = Pending
+ | InProgress
+ | Have
+ 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
+ , state :: PieceDlState -- ^ state of the piece from download perspective.
+ , hash :: ByteString -- ^ piece hash
+ , len :: Integer } -- ^ piece length
-data PieceData = PieceData { index :: Int -- ^ Piece number
- , peers :: [Peer] -- ^ list of peers who have this piece
- , state :: PieceState } -- ^ state of the piece from download perspective.
+-- which piece is with which peers
+type PieceMap = Map Integer PieceData
-- | Peer is a PeerID, IP address, port tuple
data Peer = Peer ID IP Port
| 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 -> Integer -> PieceMap
+mkPieceMap numPieces pieceHash pLen = fromList kvs
+ where kvs = [(i, PieceData { peers = []
+ , state = Pending
+ , hash = h
+ , len = pLen })
+ | (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
peerID = BC.pack peer_id
handShake :: Peer -> ByteString -> String -> IO Handle
-handShake (Peer _ ip port) infoHash peerid = do
+handShake peer@(Peer _ ip port) infoHash peerid = do
let hs = genHandShakeMsg infoHash peerid
h <- connectTo ip (PortNumber (fromIntegral port))
hSetBuffering h LineBuffering
hPut h hs
- rlenBS <- hGet h 1
- let rlen = fromIntegral $ (unpack rlenBS) !! 0
- hGet h rlen
+ putStrLn $ "--> handhake to peer: " ++ show peer
+ _ <- hGet h (length (unpack hs))
+ putStrLn $ "<-- handshake from peer: " ++ show peer
return h
instance Binary PeerMsg where
8 -> liftA3 CancelMsg getInteger getInteger getInteger
where getInteger = fromIntegral <$> getWord32be
9 -> liftM (PortMsg . fromIntegral) getWord16be
- _ -> error "unknown message ID"
+ _ -> error ("unknown message ID: " ++ show msgid)
getMsg :: Handle -> IO PeerMsg
getMsg h = do
lBS <- hGet h 4
- let (Just (l, _)) = BC.readInt lBS
- msg <- hGet h l
- return $ decode $ fromStrict $ append lBS msg
+ let l = bsToInt lBS
+ if l == 0
+ then return KeepAliveMsg
+ else do
+ msg <- hGet h l
+ return $ decode $ fromStrict $ concat [lBS, msg]
+
+sendMsg :: Handle -> PeerMsg -> IO ()
+sendMsg h msg =
+ let bsMsg = toStrict $ encode msg
+ in
+ hPut h bsMsg
+
+bsToInt :: ByteString -> Int
+bsToInt x = fromIntegral (runGet getWord32be (fromChunks (return x)))
+bitfieldToList :: [Word8] -> [Integer]
+bitfieldToList bs = go bs 0
+ where go [] _ = []
+ go (b:bs') pos =
+ let setBits = [pos*8 + toInteger i | i <- [0..8], testBit b i]
+ in
+ setBits ++ go bs' (pos + 1)
+
+-- downloadPiece :: Integer -> Handle -> IO ()
+
+createDummyFile :: FilePath -> Int -> IO ()
+createDummyFile path size =
+ writeFile path (BC.replicate size '\0')
-- loop1 :: shake hands with all peers, find out the pieces they have, form PieceData.
-- recvMsg :: Peer -> Handle -> Msg
+msgLoop :: PeerState -> PieceMap -> IO ()
+msgLoop state pieceStatus | meInterested state == False &&
+ heChoking state == True = do
+ -- if meInterested and he NOT Choking, pick a piece to download
+ -- and send a requestmsg.
+ let h = handle state
+ sendMsg h InterestedMsg
+ putStrLn $ "--> InterestedMsg to peer: " ++ show (peer state)
+ msgLoop (state { meInterested = True }) pieceStatus
+ | meInterested state == True &&
+ heChoking state == False =
+ case pickPiece pieceStatus of
+ Nothing -> putStrLn "Nothing to download"
+ Just workPiece -> do
+ let pLen = len (pieceStatus ! workPiece)
+ sendMsg (handle state) (RequestMsg workPiece 0 pLen)
+ putStrLn $ "--> RequestMsg for Piece " ++ (show workPiece) ++ "to peer: " ++ show (peer state)
+ msg <- getMsg (handle state)
+ putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer state)
+ -- msgLoop state pieceStatus
+ | otherwise = do
+ msg <- getMsg (handle state)
+ putStrLn $ "<-- " ++ show msg ++ "from peer: " ++ show (peer state)
+ case msg of
+ KeepAliveMsg -> do
+ sendMsg (handle state) KeepAliveMsg
+ putStrLn $ "--> " ++ "KeepAliveMsg to peer: " ++ show (peer state)
+ msgLoop state pieceStatus
+ BitFieldMsg bss -> do
+ let pieceList = bitfieldToList (unpack bss)
+ pieceStatus' = updatePieceAvailability pieceStatus (peer state) pieceList
+ print pieceList
+ -- 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 state pieceStatus'
+ UnChokeMsg -> do
+ msgLoop (state { heChoking = False }) pieceStatus
+ _ -> do
+ msgLoop state pieceStatus
+
+-- 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 (\(k, v) -> state v == Pending) pieceList
+ in
+ case allPending of
+ [] -> Nothing
+ ((i, _):_) -> Just i
+
+updatePieceAvailability :: PieceMap -> Peer -> [Integer] -> PieceMap
+updatePieceAvailability pieceStatus p pieceList =
+ mapWithKey (\k pd -> if k `elem` pieceList
+ then (pd { peers = p : (peers pd) })
+ else pd) pieceStatus
+
+handlePeerMsgs :: Peer -> Metainfo -> String -> (String -> IO ()) -> IO ()
+handlePeerMsgs p m peerId logFn = do
+ h <- handShake p (infoHash m) peerId
+ -- logFn "handShake"
+ let state = PeerState { handle = h
+ , peer = p
+ , heInterested = False
+ , heChoking = True
+ , meInterested = False
+ , meChoking = True }
+ pieceHash = pieces (info m)
+ numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
+ pLen = pieceLength (info m) :: Integer
+ pieceStatus = mkPieceMap numPieces pieceHash pLen
+ msgLoop state pieceStatus
+
projects / functorrent.git / blobdiff