handlePeerMsgs
) where
-import Prelude hiding (lookup, concat, replicate, splitAt, empty, writeFile)
+import Prelude hiding (lookup, concat, replicate, splitAt, take)
import System.IO (Handle, BufferMode(..), hSetBuffering)
-import Data.ByteString (ByteString, pack, unpack, concat, hGet, hPut, singleton, writeFile)
-import Data.ByteString.Lazy (fromStrict, fromChunks)
+import Data.ByteString (ByteString, pack, unpack, concat, hGet, hPut, singleton, take, empty)
+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, runGet)
-import Control.Monad (replicateM, liftM, forever)
+import Control.Monad (replicateM, liftM, forM)
import Control.Applicative ((<$>), liftA3)
import Data.Bits
import Data.Word (Word8)
-import Data.Map (Map(..), fromList, (!))
+import Data.Map (Map, fromList, toList, (!), mapWithKey, adjust)
+import qualified Crypto.Hash.SHA1 as SHA1 (hash)
import FuncTorrent.Metainfo (Info(..), Metainfo(..))
-import FuncTorrent.Utils (splitN)
+import FuncTorrent.Utils (splitN, splitNum)
+import FuncTorrent.Fileops (createDummyFile, writeFileAtOffset)
type ID = String
type IP = String
type Port = Integer
+-- PeerState is a misnomer
data PeerState = PeerState { handle :: Handle
- , amChoking :: Bool
- , amInterested :: Bool
- , peerChoking :: Bool
- , peerInterested :: Bool}
-
--- Maintain info on every piece and the current state of it.
--- should probably be a TVar.
-type Pieces = [PieceData]
+ , peer :: Peer
+ , meChoking :: Bool
+ , meInterested :: Bool
+ , heChoking :: Bool
+ , heInterested :: Bool}
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.
- , hash :: ByteString } -- ^ piece hash
+ , hash :: ByteString -- ^ piece hash
+ , len :: Integer } -- ^ piece length
-- which piece is with which peers
type PieceMap = Map Integer PieceData
-- Make the initial Piece map, with the assumption that no peer has the
-- piece and that every piece is pending download.
-mkPieceMap :: Integer -> ByteString -> PieceMap
-mkPieceMap numPieces pieceHash = fromList kvs
+mkPieceMap :: Integer -> ByteString -> [Integer] -> PieceMap
+mkPieceMap numPieces pieceHash pLengths = fromList kvs
where kvs = [(i, PieceData { peers = []
, state = Pending
- , hash = h }) | (i, h) <- zip [0..numPieces] hashes]
- hashes = splitN (fromIntegral numPieces) pieceHash
+ , hash = h
+ , len = pLen })
+ | (i, h, pLen) <- zip3 [0..numPieces] hashes pLengths]
+ hashes = splitN 20 pieceHash
havePiece :: PieceMap -> Integer -> Bool
havePiece pm index =
reserved = BC.replicate 8 '\0'
peerID = BC.pack peer_id
-handShake :: Peer -> ByteString -> String -> IO Handle
-handShake (Peer _ ip port) infoHash peerid = do
- let hs = genHandShakeMsg infoHash peerid
+connectToPeer :: Peer -> IO Handle
+connectToPeer peer@(Peer _ ip port) = do
h <- connectTo ip (PortNumber (fromIntegral port))
hSetBuffering h LineBuffering
- hPut h hs
- rlenBS <- hGet h (length (unpack hs))
- putStrLn $ "got handshake from peer: " ++ show rlenBS
return h
+doHandShake :: Handle -> Peer -> ByteString -> String -> IO ()
+doHandShake h peer infoHash peerid = do
+ let hs = genHandShakeMsg infoHash peerid
+ hPut h hs
+ putStrLn $ "--> handhake to peer: " ++ show peer
+ _ <- hGet h (length (unpack hs))
+ putStrLn $ "<-- handshake from peer: " ++ show peer
+ return ()
+
instance Binary PeerMsg where
put msg = case msg of
KeepAliveMsg -> putWord32be 0
msg <- hGet h l
return $ decode $ fromStrict $ concat [lBS, msg]
+sendMsg :: Handle -> PeerMsg -> IO ()
+sendMsg h msg = hPut h bsMsg
+ where bsMsg = toStrict $ encode msg
bsToInt :: ByteString -> Int
bsToInt x = fromIntegral (runGet getWord32be (fromChunks (return x)))
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 :: Handle -> ByteString -> IO ()
-msgLoop h pieceHash =
- let numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
- pieceStatus = mkPieceMap numPieces pieceHash
+msgLoop :: PeerState -> PieceMap -> IO ()
+msgLoop pState pieceStatus | not (meInterested pState) && heChoking pState = 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
+ | meInterested pState && not (heChoking pState) =
+ -- 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)
+ | otherwise = 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
+
+-- 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
in
- forever $ do
- msg <- getMsg h
- putStrLn $ "got a " ++ show msg
- case msg of
- BitFieldMsg bss -> do
- let pieceList = bitfieldToList (unpack bss)
- print pieceList
- -- download each of the piece in order
- _ -> print msg
-
-handlePeerMsgs :: Peer -> Metainfo -> String -> (String -> IO ()) -> IO ()
-handlePeerMsgs p m peerId logFn = do
- h <- handShake p (infoHash m) peerId
- logFn "handShake"
- msgLoop h (pieces (info m))
+ 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 -> IO ()
+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 }
+ pieceHash = pieces (info m)
+ numPieces = (toInteger . (`quot` 20) . BC.length) pieceHash
+ pLen = pieceLength (info m)
+ fileLen = lengthInBytes (info m)
+ pieceStatus = mkPieceMap numPieces pieceHash (splitNum fileLen pLen)
+ createDummyFile "/tmp/download.file" (fromIntegral fileLen)
+ msgLoop state pieceStatus
+downloadPiece :: Handle -> Integer -> Integer -> IO ByteString
+downloadPiece h index pieceLength = do
+ let chunks = splitNum pieceLength 16384
+ liftM concat $ forM (zip [0..] chunks) (\(i, pLen) -> do
+ sendMsg h (RequestMsg index (i*pLen) pLen)
+ putStrLn $ "--> " ++ "RequestMsg for Piece "
+ ++ show index ++ ", part: " ++ show i ++ " of length: "
+ ++ show pLen
+ msg <- getMsg h
+ case msg of
+ PieceMsg index begin block -> do
+ putStrLn $ " <-- PieceMsg for Piece: "
+ ++ show index
+ ++ ", offset: "
+ ++ show begin
+ return block
+ _ -> do
+ putStrLn "ignoring irrelevant msg"
+ return empty)
+
+verifyHash :: ByteString -> ByteString -> Bool
+verifyHash bs pieceHash =
+ take 20 (SHA1.hash bs) == pieceHash
projects / functorrent.git / blobdiff