misc cleanups in Http tracker

[functorrent.git] / src / FuncTorrent / Tracker / Http.hs

diff --git a/src/FuncTorrent/Tracker/Http.hs b/src/FuncTorrent/Tracker/Http.hs
index 0cb36b9e8955ae4ec738ea2ecde6b248c99cf1f4..5caefd663acbce46cc91dc6243623790724ea79a 100644 (file)
--- a/src/FuncTorrent/Tracker/Http.hs
+++ b/src/FuncTorrent/Tracker/Http.hs
@@ -1,22 +1,23 @@
-{-# LANGUAGE OverloadedStrings #-}
 {-
-Copyright (C) 2015-2016 Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
-
-This file is part of FuncTorrent.
-
-FuncTorrent is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 3 of the License, or
-(at your option) any later version.
+ - Copyright (C) 2015-2016 Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
+ -
+ - This file is part of FuncTorrent.
+ -
+ - FuncTorrent is free software; you can redistribute it and/or modify
+ - it under the terms of the GNU General Public License as published by
+ - the Free Software Foundation; either version 3 of the License, or
+ - (at your option) any later version.
+ -
+ - FuncTorrent is distributed in the hope that it will be useful,
+ - but WITHOUT ANY WARRANTY; without even the implied warranty of
+ - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ - GNU General Public License for more details.
+ -
+ - You should have received a copy of the GNU General Public License
+ - along with FuncTorrent; if not,  see <http://www.gnu.org/licenses/>
+ -}
 
-FuncTorrent is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with FuncTorrent; if not,  see <http://www.gnu.org/licenses/>
--}
+{-# LANGUAGE OverloadedStrings #-}
 
 module FuncTorrent.Tracker.Http
        (trackerLoop
@@ -25,7 +26,7 @@ module FuncTorrent.Tracker.Http
 import Prelude hiding (lookup, splitAt)
 
 import Control.Concurrent (threadDelay)
-import Control.Concurrent.MVar (readMVar, putMVar)
+import Control.Concurrent.MVar (readMVar, putMVar, isEmptyMVar, swapMVar)
 import Control.Monad (forever)
 import qualified Data.ByteString.Base16 as B16 (encode)
 import Data.ByteString (ByteString)
@@ -80,14 +81,21 @@ trackerLoop url port peerId infohash fschan tstate = forever $ do
       down = FS.bytesWritten st
   resp <- sendGetRequest url $ mkArgs port peerId up down (left tstate) infohash
   case Benc.decode resp of
-    Left e -> return () -- $ pack (show e)
+    Left e -> do
+      return () -- $ pack (show e)
     Right trackerInfo ->
       case parseTrackerResponse trackerInfo of
         Left e -> return () -- e
         Right tresp -> do
           _ <- threadDelay $ fromIntegral (interval tresp)
-          _ <- putMVar (connectedPeers tstate) (peers tresp)
-          return () -- trackerLoop port peerId st
+          ps <- isEmptyMVar $ connectedPeers tstate
+          if ps
+            then do
+            _ <- putMVar (connectedPeers tstate) (peers tresp)
+            return ()
+            else do
+            _ <- swapMVar (connectedPeers tstate) (peers tresp)
+            return ()
 
 parseTrackerResponse :: BVal -> Either ByteString TrackerResponse
 parseTrackerResponse resp =