refactor the piecemap initialization

[functorrent.git] / src / main / Main.hs

diff --git a/src/main/Main.hs b/src/main/Main.hs
index ae3c0354e76a7b714db629388211551bd091600f..79cd9bf7f06fc7497d8ba81f02aa644f49c7e644 100644 (file)
--- a/src/main/Main.hs
+++ b/src/main/Main.hs
@@ -1,10 +1,10 @@
 {-# LANGUAGE OverloadedStrings #-}
 module Main where
 
-import Prelude hiding (log, length, readFile, getContents)
+import Prelude hiding (log, length, readFile, getContents, replicate, writeFile)
 
 import Control.Concurrent (forkIO)
-import Data.ByteString.Char8 (ByteString, getContents, readFile, unpack)
+import Data.ByteString.Char8 (ByteString, getContents, readFile, writeFile, unpack, replicate)
 import Network (PortID (PortNumber))
 import System.Environment (getArgs)
 import System.Exit (exitSuccess)
@@ -13,7 +13,7 @@ import System.Random (getStdGen, randomRs)
 
 import FuncTorrent.Logger (initLogger, logMessage, logStop)
 import FuncTorrent.Metainfo (Info(..), Metainfo(..), torrentToMetainfo)
-import FuncTorrent.Peer (handlePeerMsgs)
+import FuncTorrent.Peer (initPieceMap, handlePeerMsgs, pieceMapFromFile)
 import qualified FuncTorrent.Server as Server
 import FuncTorrent.Tracker (peers, getTrackerResponse)
 
@@ -57,18 +57,30 @@ main = do
     case torrentToMetainfo torrentStr of
      Left e -> logError e log
      Right m -> do
-       let p = name (info m)
-       log $ "Downloading file : " ++ p
        -- if we had downloaded the file before (partly or completely)
        -- then we should check the current directory for the existence
        -- of the file and then update the map of each piece' availability.
        -- This can be donw by reading each piece and verifying the checksum.
        -- If the checksum does not match, we don't have that piece.
+       let filePath = name (info m) -- really this is just the file name, not file path
+           fileLen = lengthInBytes (info m)
+           pieceHash = pieces (info m)
+           pLen = pieceLength (info m)
+           defaultPieceMap = initPieceMap pieceHash fileLen pLen
+       log $ "Downloading file : " ++ filePath
+       dfe <- doesFileExist filePath
+       pieceMap <- if dfe
+                   then
+                     pieceMapFromFile filePath defaultPieceMap
+                   else do
+                     -- create a dummy file
+                     _ <- writeFile filePath (replicate (fromIntegral fileLen) '\0')
+                     return defaultPieceMap
        log $ "starting server"
        (serverSock, (PortNumber portnum)) <- Server.start
        log $ "server started on " ++ show portnum
        log "Trying to fetch peers"
-       forkIO $ Server.run serverSock peerId m
+       forkIO $ Server.run serverSock peerId m pieceMap
        log $ "Trackers: " ++ head (announceList m)
        trackerResp <- getTrackerResponse portnum peerId m
        case  trackerResp of
@@ -76,5 +88,5 @@ main = do
         Right peerList -> do
           log $ "Peers List : " ++ (show . peers $ peerList)
           let p1 = head (peers peerList)
-          handlePeerMsgs p1 peerId m
+          handlePeerMsgs p1 peerId m pieceMap
     logStop logR