3 files changed, 111 insertions, 95 deletions

diff --git a/src/Network/BitTorrent/Client/Handle.hs b/src/Network/BitTorrent/Client/Handle.hs
index 9601e691..5bcb2d33 100644
--- a/src/Network/BitTorrent/Client/Handle.hs
+++ b/src/Network/BitTorrent/Client/Handle.hs
@@ -71,10 +71,10 @@ lookupHandle ih = do
 --  Initialization
 -----------------------------------------------------------------------}
 
-newExchangeSession :: FilePath -> InfoDict -> BitTorrent Exchange.Session
-newExchangeSession rootPath dict = do
+newExchangeSession :: FilePath -> Either InfoHash InfoDict -> BitTorrent Exchange.Session
+newExchangeSession rootPath source = do
   c @ Client {..} <- getClient
-  liftIO $ Exchange.newSession clientLogger (externalAddr c) rootPath dict
+  liftIO $ Exchange.newSession clientLogger (externalAddr c) rootPath source
 
 -- | Open a torrent in 'stop'ed state. Use 'nullTorrent' to open
 -- handle from 'InfoDict'. This operation do not block.
@@ -83,7 +83,7 @@ openTorrent rootPath t @ Torrent {..} = do
   let ih = idInfoHash tInfoDict
   allocHandle ih $ do
     tses <- liftIO $ Tracker.newSession ih (trackerList t)
-    eses <- newExchangeSession rootPath tInfoDict
+    eses <- newExchangeSession rootPath (Right tInfoDict)
     return $ Handle
       { handleTopic    = ih
       , handlePrivate  = idPrivate tInfoDict
@@ -96,7 +96,7 @@ openMagnet :: FilePath -> Magnet -> BitTorrent Handle
 openMagnet rootPath uri @ Magnet {..} = do
   allocHandle exactTopic $ do
     tses <- liftIO $ Tracker.newSession exactTopic def
-    eses <- newExchangeSession rootPath (error "openMagnet" exactTopic)
+    eses <- newExchangeSession rootPath (Left exactTopic)
     return $ Handle
       { handleTopic    = exactTopic
       , handlePrivate  = False
diff --git a/src/Network/BitTorrent/Exchange/Session.hs b/src/Network/BitTorrent/Exchange/Session.hs
index 57d21579..b6d7f810 100644
--- a/src/Network/BitTorrent/Exchange/Session.hs
+++ b/src/Network/BitTorrent/Exchange/Session.hs
@@ -76,7 +76,7 @@ packException :: Exception e => (e -> ExchangeError) -> IO a -> IO a
 packException f m = try m >>= either (throwIO . f) return
 
 {-----------------------------------------------------------------------
---  Session
+--  Session state
 -----------------------------------------------------------------------}
 -- TODO unmap storage on zero connections
 
@@ -91,18 +91,56 @@ cache s = Cached s (BE.encode s)
 -- | Logger function.
 type LogFun = Loc -> LogSource -> LogLevel -> LogStr -> IO ()
 
+--data SessionStatus = Seeder | Leecher
+
+data SessionState
+  = WaitingMetadata
+    { metadataDownload  :: MVar Metadata.Status
+    , metadataCompleted :: MVar InfoDict -- ^ used to unblock waiters
+    , contentRootPath   :: FilePath
+    }
+  | HavingMetadata
+    { metadataCache     :: Cached InfoDict
+    , contentDownload   :: MVar SessionStatus
+    , contentStorage    :: Storage
+    }
+
+newSessionState :: FilePath -> Either InfoHash InfoDict -> IO SessionState
+newSessionState rootPath (Left  ih  ) = do
+  WaitingMetadata <$> newMVar def <*> newEmptyMVar <*> pure rootPath
+newSessionState rootPath (Right dict) = do
+  storage     <- openInfoDict ReadWriteEx rootPath dict
+  download    <- newMVar $ sessionStatus (BF.haveNone (totalPieces storage))
+                                        (piPieceLength (idPieceInfo dict))
+  return $ HavingMetadata (cache dict) download storage
+
+closeSessionState :: SessionState -> IO ()
+closeSessionState WaitingMetadata {..} = return ()
+closeSessionState HavingMetadata  {..} = close contentStorage
+
+haveMetadata :: InfoDict -> SessionState -> IO SessionState
+haveMetadata dict WaitingMetadata {..} = do
+  storage     <- openInfoDict ReadWriteEx contentRootPath dict
+  download    <- newMVar $ sessionStatus (BF.haveNone (totalPieces storage))
+                                        (piPieceLength (idPieceInfo dict))
+  return HavingMetadata
+    { metadataCache   = cache dict
+    , contentDownload = download
+    , contentStorage  = storage
+    }
+haveMetadata _    s                    = return s
+
+{-----------------------------------------------------------------------
+--  Session
+-----------------------------------------------------------------------}
+
 data Session = Session
   { sessionPeerId          :: !(PeerId)
   , sessionTopic           :: !(InfoHash)
   , sessionLogger          :: !(LogFun)
   , sessionEvents          :: !(SendPort SessionEvent)
 
-------------------------------------------------------------------------
-  , metadata               :: !(MVar Metadata.Status)
-  , infodict               :: !(MVar (Cached InfoDict))
-
-  , status                 :: !(MVar SessionStatus)
-  , sessionStorage         :: !(MVar Storage)
+  , sessionState           :: !(MVar SessionState)
 
 ------------------------------------------------------------------------
   , connectionsPrefs       :: !ConnectionPrefs
@@ -124,44 +162,26 @@ data Session = Session
   , connectionsBroadcast   :: !(Chan Message)
   }
 
-{-----------------------------------------------------------------------
---  Session construction
------------------------------------------------------------------------}
-
 newSession :: LogFun
-           -> PeerAddr (Maybe IP) -- ^ /external/ address of this peer;
-           -> FilePath            -- ^ root directory for content files;
-           -> InfoDict            -- ^ torrent info dictionary;
-           -> IO Session          -- ^
-newSession logFun addr rootPath dict = do
+           -> PeerAddr (Maybe IP)      -- ^ /external/ address of this peer;
+           -> FilePath                 -- ^ root directory for content files;
+           -> Either InfoHash InfoDict -- ^ torrent info dictionary;
+           -> IO Session
+newSession logFun addr rootPath source = do
+  let ih       = either id idInfoHash source
   pid         <- maybe genPeerId return (peerId addr)
-  let ih = idInfoHash dict
   eventStream <- newSendPort
-
-  storage     <- openInfoDict ReadWriteEx rootPath dict
-  storageVar  <- newMVar storage
-
-  statusVar   <- newMVar $ sessionStatus (BF.haveNone (totalPieces storage))
-                                         (piPieceLength (idPieceInfo dict))
-
-  metadataVar <- newMVar (error "sessionMetadata")
-  infodictVar <- newMVar (cache dict)
-
+  sState      <- newSessionState rootPath source
+  sStateVar   <- newMVar sState
   pSetVar     <- newTVarIO S.empty
   eSetVar     <- newTVarIO M.empty
   chan        <- newChan
-
   return Session
     { sessionPeerId          = pid
     , sessionTopic           = ih
     , sessionLogger          = logFun
     , sessionEvents          = eventStream
-
-    , metadata               = metadataVar
-    , infodict               = infodictVar
-    , status                 = statusVar
-    , sessionStorage         = storageVar
-
+    , sessionState           = sStateVar
     , connectionsPrefs       = def
     , connectionsPending     = pSetVar
     , connectionsEstablished = eSetVar
@@ -171,8 +191,8 @@ newSession logFun addr rootPath dict = do
 
 closeSession :: Session -> IO ()
 closeSession Session {..} = do
-  mstorage <- tryReadMVar sessionStorage
-  maybe (return ()) close mstorage
+  s <- readMVar sessionState
+  closeSessionState s
 {-
   hSet <- atomically $ do
     pSet <- swapTVar connectionsPending     S.empty
@@ -341,22 +361,6 @@ tryReadMVar m = do
   maybe (return ()) (putMVar m) ma
   return ma
 
-withStatusUpdates :: StatusUpdates a -> Wire Session a
-withStatusUpdates m = do
-  Session {..} <- asks connSession
-  liftIO $ runStatusUpdates status m
-
-withMetadataUpdates :: Updates a -> Connected Session a
-withMetadataUpdates m = do
-  Session {..} <- asks connSession
-  addr         <- asks connRemoteAddr
-  liftIO $ runUpdates metadata addr m
-
-getThisBitfield :: Wire Session Bitfield
-getThisBitfield = do
-  ses <- asks connSession
-  liftIO $ SS.getBitfield (status ses)
-
 readBlock :: BlockIx -> Storage -> IO (Block BL.ByteString)
 readBlock bix @ BlockIx {..} s = do
   p <- packException (InvalidRequest bix) $ do readPiece ixPiece s
@@ -371,10 +375,10 @@ tryReadMetadataBlock :: PieceIx
    -> Connected Session (Maybe (Torrent.Piece BS.ByteString, Int))
 tryReadMetadataBlock pix = do
   Session {..} <- asks connSession
-  mcached      <- liftIO (tryReadMVar infodict)
-  case mcached of
-    Nothing            -> error "tryReadMetadataBlock"
-    Just (Cached {..}) -> error "tryReadMetadataBlock"
+  s            <- liftIO (readMVar sessionState)
+  case s of
+    WaitingMetadata {..} -> error "tryReadMetadataBlock"
+    HavingMetadata  {..} -> error "tryReadMetadataBlock"
 
 sendBroadcast :: PeerMessage msg => msg -> Wire Session ()
 sendBroadcast msg = do
@@ -383,10 +387,18 @@ sendBroadcast msg = do
 --  liftIO $ msg `broadcast` sessionConnections
 
 waitMetadata :: Session -> IO InfoDict
-waitMetadata Session {..} = cachedValue <$> readMVar infodict
+waitMetadata Session {..} = do
+  s <- readMVar sessionState
+  case s of
+    WaitingMetadata {..} -> readMVar metadataCompleted
+    HavingMetadata  {..} -> return (cachedValue metadataCache)
 
 takeMetadata :: Session -> IO (Maybe InfoDict)
-takeMetadata Session {..} = fmap cachedValue <$> tryReadMVar infodict
+takeMetadata Session {..} = do
+  s <- readMVar sessionState
+  case s of
+    WaitingMetadata {..} -> return Nothing
+    HavingMetadata  {..} -> return (Just (cachedValue metadataCache))
 
 {-----------------------------------------------------------------------
 --  Triggers
@@ -405,12 +417,13 @@ interesting = do
 fillRequestQueue :: Trigger
 fillRequestQueue = do
   maxN <- lift getMaxQueueLength
-  rbf  <- use connBitfield
+  rbf  <- use  connBitfield
   addr <- asks connRemoteAddr
-  blks <- withStatusUpdates $ do
-    n <- getRequestQueueLength addr
-    scheduleBlocks addr rbf (maxN - n)
-  mapM_ (sendMessage . Request) blks
+--  blks <- withStatusUpdates $ do
+--    n <- getRequestQueueLength addr
+--    scheduleBlocks addr rbf (maxN - n)
+--  mapM_ (sendMessage . Request) blks
+  return ()
 
 tryFillRequestQueue :: Trigger
 tryFillRequestQueue = do
@@ -431,7 +444,8 @@ handleStatus s = do
     Interested _     -> return ()
     Choking    True  -> do
       addr <- asks connRemoteAddr
-      withStatusUpdates (SS.resetPending addr)
+--      withStatusUpdates (SS.resetPending addr)
+      return ()
     Choking    False -> tryFillRequestQueue
 
 handleAvailable :: Handler Available
@@ -440,7 +454,8 @@ handleAvailable msg = do
     Have     ix -> BF.insert ix
     Bitfield bf -> const     bf
 
-  thisBf <- getThisBitfield
+  --thisBf <- getThisBitfield
+  thisBf <- undefined
   case msg of
     Have     ix
       | ix `BF.member`     thisBf -> return ()
@@ -452,23 +467,23 @@ handleAvailable msg = do
 handleTransfer :: Handler Transfer
 handleTransfer (Request bix) = do
   Session {..} <- asks connSession
-  bitfield <- getThisBitfield
-  upload   <- canUpload <$> use connStatus
-  when (upload && ixPiece bix `BF.member` bitfield) $ do
-    mstorage <- liftIO $ tryReadMVar sessionStorage
-    case mstorage of
-      Nothing -> return ()
-      Just storage -> do
-        blk <- liftIO $ readBlock bix storage
+  s            <- liftIO $ readMVar sessionState
+  case s of
+    WaitingMetadata {..} -> return ()
+    HavingMetadata  {..} -> do
+      bitfield <- undefined -- getThisBitfield
+      upload   <- canUpload <$> use connStatus
+      when (upload && ixPiece bix `BF.member` bitfield) $ do
+        blk <- liftIO $ readBlock bix contentStorage
         sendMessage (Message.Piece blk)
 
 handleTransfer (Message.Piece   blk) = do
   Session {..} <- asks connSession
-  mstorage <- liftIO $ tryReadMVar sessionStorage
-  case mstorage of
-    Nothing -> return () -- TODO (?) break connection
-    Just storage -> do
-      isSuccess <- withStatusUpdates (SS.pushBlock blk storage)
+  s            <- liftIO $ readMVar sessionState
+  case s of
+    WaitingMetadata {..} -> return () -- TODO (?) break connection
+    HavingMetadata  {..} -> do
+      isSuccess <- undefined -- withStatusUpdates (SS.pushBlock blk storage)
       case isSuccess of
         Nothing -> liftIO $ throwIO $ userError "block is not requested"
         Just isCompleted -> do
@@ -490,25 +505,20 @@ handleTransfer (Cancel  bix) = filterQueue (not . (transferResponse bix))
 waitForMetadata :: Trigger
 waitForMetadata = do
   Session {..} <- asks connSession
-  needFetch    <- liftIO (isEmptyMVar infodict)
+  needFetch    <- undefined --liftIO (isEmptyMVar infodict)
   when needFetch $ do
     canFetch   <- allowed ExtMetadata <$> use connExtCaps
     if canFetch
       then tryRequestMetadataBlock
-      else liftIO (waitMVar infodict)
+      else undefined -- liftIO (waitMVar infodict)
 
 tryRequestMetadataBlock :: Trigger
 tryRequestMetadataBlock = do
-  mpix <- lift $ withMetadataUpdates Metadata.scheduleBlock
+  mpix <- lift $ undefined --withMetadataUpdates Metadata.scheduleBlock
   case mpix of
     Nothing  -> error "tryRequestMetadataBlock"
     Just pix -> sendMessage (MetadataRequest pix)
 
-metadataCompleted :: InfoDict -> Trigger
-metadataCompleted dict = do
-  Session {..} <- asks connSession
-  liftIO $ putMVar infodict (cache dict)
-
 handleMetadata :: Handler ExtendedMetadata
 handleMetadata (MetadataRequest pix) =
     lift (tryReadMetadataBlock pix) >>= sendMessage . mkResponse
@@ -518,13 +528,15 @@ handleMetadata (MetadataRequest pix) =
 
 handleMetadata (MetadataData   {..}) = do
   ih    <- asks connTopic
-  mdict <- lift $ withMetadataUpdates (Metadata.pushBlock piece ih)
+  mdict <- lift $ undefined --withMetadataUpdates (Metadata.pushBlock piece ih)
   case mdict of
     Nothing   -> tryRequestMetadataBlock -- not completed, need all blocks
-    Just dict -> metadataCompleted dict  -- complete, wake up payload fetch
+    Just dict -> do   -- complete, wake up payload fetch
+      Session {..} <- asks connSession
+      liftIO $ modifyMVar_ sessionState (haveMetadata dict)
 
 handleMetadata (MetadataReject  pix) = do
-  lift $ withMetadataUpdates (Metadata.cancelPending pix)
+  lift $ undefined -- withMetadataUpdates (Metadata.cancelPending pix)
 
 handleMetadata (MetadataUnknown _  ) = do
   logInfoN "Unknown metadata message"
@@ -553,7 +565,7 @@ handleMessage (Extended  msg) = handleExtended msg
 exchange :: Wire Session ()
 exchange = do
   waitForMetadata
-  bf <- getThisBitfield
+  bf <- undefined --getThisBitfield
   sendMessage (Bitfield bf)
   awaitForever handleMessage
 
diff --git a/src/Network/BitTorrent/Exchange/Session/Metadata.hs b/src/Network/BitTorrent/Exchange/Session/Metadata.hs
index 79fd03b0..79156e2e 100644
--- a/src/Network/BitTorrent/Exchange/Session/Metadata.hs
+++ b/src/Network/BitTorrent/Exchange/Session/Metadata.hs
@@ -21,6 +21,7 @@ import Control.Monad.Reader
 import Control.Monad.State
 import Data.ByteString as BS
 import Data.ByteString.Lazy as BL
+import Data.Default
 import Data.List as L
 import Data.Tuple
 
@@ -41,6 +42,9 @@ data Status = Status
 
 makeLenses ''Status
 
+instance Default Status where
+  def = error "default status"
+
 -- | Create a new scheduler for infodict of the given size.
 nullStatus :: Int -> Status
 nullStatus ps = Status [] (Block.empty ps)