data: new test torrent

[functorrent.git] / src / FuncTorrent / Utils.hs

diff --git a/src/FuncTorrent/Utils.hs b/src/FuncTorrent/Utils.hs
index cf6c2844f2745152b91926c272fab1c664bfabea..30fd160408b55119bdef8d8d8537dba6d22c2640 100644 (file)
--- a/src/FuncTorrent/Utils.hs
+++ b/src/FuncTorrent/Utils.hs
@@ -1,6 +1,51 @@
-module FuncTorrent.Utils where
+{-
+ - 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/>
+ -}
 
+module FuncTorrent.Utils
+       ( createDummyFile
+       , writeFileAtOffset
+       , readFileAtOffset
+       , splitNum
+       , splitN
+       , verifyHash
+       , IP
+       , Port
+       , toIP
+       , toPort
+       , getHostname
+       , getPort
+       )
+       where
+
+import Prelude hiding (writeFile, take)
+
+import qualified Crypto.Hash.SHA1 as SHA1 (hash)
+import Control.Exception.Base (IOException, try)
+import Data.ByteString (ByteString, writeFile, hPut, hGet, take)
+import qualified Data.ByteString.Base16 as B16 (encode)
 import qualified Data.ByteString.Char8 as BC
+import Data.List (intercalate)
+import System.IO (Handle, hSeek, SeekMode(..))
+import System.Directory (doesFileExist)
+
+type IP = String
+type Port = Integer
 
 splitN :: Int -> BC.ByteString -> [BC.ByteString]
 splitN n bs | BC.null bs = []
@@ -10,3 +55,44 @@ splitNum :: Integer -> Integer -> [Integer]
 splitNum n d | n == 0 = []
              | n < d = [n]
              | otherwise = d : splitNum (n - d) d
+
+createDummyFile :: FilePath -> Int -> IO (Either IOException ())
+createDummyFile path size = do
+  dfe <- doesFileExist path
+  if not dfe
+    then
+    try $ writeFile path (BC.replicate size '\0')
+    else
+    return $ Right ()
+
+-- write into a file at a specific offet
+writeFileAtOffset :: Handle -> Integer -> ByteString -> IO ()
+writeFileAtOffset h offset block = do
+  hSeek h AbsoluteSeek offset
+  hPut h block
+
+readFileAtOffset :: Handle -> Integer -> Integer -> IO ByteString
+readFileAtOffset h offset len = do
+  hSeek h AbsoluteSeek offset
+  hGet h (fromInteger len)
+
+verifyHash :: ByteString -> ByteString -> Bool
+verifyHash bs pieceHash =
+  take 20 (SHA1.hash bs) == pieceHash
+
+toPort :: ByteString -> Port
+toPort = read . ("0x" ++) . BC.unpack . B16.encode
+
+toIP :: ByteString -> IP
+toIP = Data.List.intercalate "." .
+       map (show . toInt . ("0x" ++) . BC.unpack) .
+       splitN 2 . B16.encode
+
+toInt :: String -> Integer
+toInt = read
+
+getHostname :: String -> String
+getHostname url = takeWhile (/= ':') $ drop 2 $ dropWhile (/= '/') url
+
+getPort :: String -> Port
+getPort url = read $ takeWhile (/= '/') $ drop 1 $ dropWhile (/= ':') $ drop 2 $ dropWhile (/= '/') url