2 - Copyright (C) 2015-2016 Ramakrishnan Muthukrishnan <ram@rkrishnan.org>
4 - This file is part of FuncTorrent.
6 - FuncTorrent is free software; you can redistribute it and/or modify
7 - it under the terms of the GNU General Public License as published by
8 - the Free Software Foundation; either version 3 of the License, or
9 - (at your option) any later version.
11 - FuncTorrent is distributed in the hope that it will be useful,
12 - but WITHOUT ANY WARRANTY; without even the implied warranty of
13 - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 - GNU General Public License for more details.
16 - You should have received a copy of the GNU General Public License
17 - along with FuncTorrent; if not, see <http://www.gnu.org/licenses/>
20 module FuncTorrent.Utils
34 import Prelude hiding (writeFile, take)
36 import qualified Crypto.Hash.SHA1 as SHA1 (hash)
37 import Control.Exception.Base (IOException, try)
38 import Data.ByteString (ByteString, writeFile, hPut, hGet, take)
39 import qualified Data.ByteString.Base16 as B16 (encode)
40 import qualified Data.ByteString.Char8 as BC
41 import Data.List (intercalate)
42 import System.IO (Handle, hSeek, SeekMode(..))
43 import System.Directory (doesFileExist)
48 splitN :: Int -> BC.ByteString -> [BC.ByteString]
49 splitN n bs | BC.null bs = []
50 | otherwise = BC.take n bs : splitN n (BC.drop n bs)
52 splitNum :: Integer -> Integer -> [Integer]
53 splitNum n d | n == 0 = []
55 | otherwise = d : splitNum (n - d) d
57 createDummyFile :: FilePath -> Int -> IO (Either IOException ())
58 createDummyFile path size = do
59 dfe <- doesFileExist path
62 try $ writeFile path (BC.replicate size '\0')
66 -- write into a file at a specific offet
67 writeFileAtOffset :: Handle -> Integer -> ByteString -> IO ()
68 writeFileAtOffset h offset block = do
69 hSeek h AbsoluteSeek offset
72 readFileAtOffset :: Handle -> Integer -> Integer -> IO ByteString
73 readFileAtOffset h offset len = do
74 hSeek h AbsoluteSeek offset
75 hGet h (fromInteger len)
77 verifyHash :: ByteString -> ByteString -> Bool
78 verifyHash bs pieceHash =
79 take 20 (SHA1.hash bs) == pieceHash
81 toPort :: ByteString -> Port
82 toPort = read . ("0x" ++) . BC.unpack . B16.encode
84 toIP :: ByteString -> IP
85 toIP = Data.List.intercalate "." .
86 map (show . toInt . ("0x" ++) . BC.unpack) .
89 toInt :: String -> Integer