-- | -- Copyright : (c) Sam T. 2013 -- License : MIT -- Maintainer : pxqr.sta@gmail.com -- Stability : experimental -- Portability : portable -- {-# OPTIONS -fno-warn-orphans #-} {-# LANGUAGE OverloadedStrings #-} -- | This module provides torrent metainfo serialization. module Data.Torrent ( module Data.Torrent.InfoHash , Torrent(..), ContentInfo(..), FileInfo(..) , contentLength, pieceCount, blockCount , Layout, contentLayout , isSingleFile, isMultiFile , fromFile , sizeInBase ) where import Control.Applicative import Control.Arrow import qualified Data.Map as M import Data.ByteString (ByteString) import qualified Data.ByteString as B import qualified Data.ByteString.Char8 as BC (pack, unpack) import Data.Text (Text) import Data.BEncode import Data.Torrent.InfoHash import Network.URI import System.FilePath type Time = Text -- TODO more convenient form of torrent info. -- | Metainfo about particular torrent. data Torrent = Torrent { tInfoHash :: InfoHash -- ^ SHA1 hash of the 'TorrentInfo' of the 'Torrent'. , tAnnounce :: URI -- ^ The URL of the tracker. , tAnnounceList :: Maybe [[URI]] -- ^ Announce list add multiple tracker support. -- -- BEP 12: , tComment :: Maybe Text -- ^ Free-form comments of the author. , tCreatedBy :: Maybe ByteString -- ^ Name and version of the program used to create the .torrent. , tCreationDate :: Maybe Time -- ^ Creation time of the torrent, in standard UNIX epoch. , tEncoding :: Maybe ByteString -- ^ String encoding format used to generate the pieces part of -- the info dictionary in the .torrent metafile. , tInfo :: ContentInfo -- ^ Info about each content file. , tPublisher :: Maybe URI -- ^ Containing the RSA public key of the publisher of the torrent. -- Private counterpart of this key that has the authority to allow -- new peers onto the swarm. , tPublisherURL :: Maybe URI , tSignature :: Maybe ByteString -- ^ The RSA signature of the info dictionary (specifically, -- the encrypted SHA-1 hash of the info dictionary). } deriving Show -- | Info part of the .torrent file contain info about each content file. data ContentInfo = SingleFile { ciLength :: Integer -- ^ Length of the file in bytes. , ciMD5sum :: Maybe ByteString -- ^ 32 character long MD5 sum of the file. -- Used by third-party tools, not by bittorrent protocol itself. , ciName :: ByteString -- ^ Suggested name of the file single file. , ciPieceLength :: Int -- ^ Number of bytes in each piece. , ciPieces :: ByteString -- ^ Concatenation of all 20-byte SHA1 hash values. , ciPrivate :: Maybe Bool -- ^ If set the client MUST publish its presence to get other peers ONLY -- via the trackers explicity described in the metainfo file. -- -- BEP 27: } | MultiFile { ciFiles :: [FileInfo] -- ^ List of the all files that torrent contains. , ciName :: ByteString -- | The file path of the directory in which to store all the files. , ciPieceLength :: Int , ciPieces :: ByteString , ciPrivate :: Maybe Bool } deriving (Show, Read, Eq) -- | Contain info about one single file. data FileInfo = FileInfo { fiLength :: Integer -- ^ Length of the file in bytes. , fiMD5sum :: Maybe ByteString -- ^ 32 character long MD5 sum of the file. -- Used by third-party tools, not by bittorrent protocol itself. , fiPath :: [ByteString] -- ^ One or more string elements that together represent the path and -- filename. Each element in the list corresponds to either a directory -- name or (in the case of the last element) the filename. -- For example, the file "dir1/dir2/file.ext" would consist of three -- string elements ["dir1", "dir2", "file.ext"] } deriving (Show, Read, Eq) instance BEncodable URI where toBEncode uri = toBEncode (BC.pack (uriToString id uri "")) {-# INLINE toBEncode #-} fromBEncode (BString s) | Just url <- parseURI (BC.unpack s) = return url fromBEncode b = decodingError $ "url <" ++ show b ++ ">" {-# INLINE fromBEncode #-} instance BEncodable Torrent where toBEncode t = fromAscAssocs [ "announce" --> tAnnounce t , "announce-list" -->? tAnnounceList t , "comment" -->? tComment t , "created by" -->? tCreatedBy t , "creation date" -->? tCreationDate t , "encoding" -->? tEncoding t , "info" --> tInfo t , "publisher" -->? tPublisher t , "publisher-url" -->? tPublisherURL t , "signature" -->? tSignature t ] fromBEncode (BDict d) | Just info <- M.lookup "info" d = Torrent <$> pure (hashlazy (encode info)) -- WARN <*> d >-- "announce" <*> d >--? "announce-list" <*> d >--? "comment" <*> d >--? "created by" <*> d >--? "creation date" <*> d >--? "encoding" <*> d >-- "info" <*> d >--? "publisher" <*> d >--? "publisher-url" <*> d >--? "singature" fromBEncode _ = decodingError "Torrent" instance BEncodable ContentInfo where toBEncode ti@(SingleFile { }) = fromAscAssocs [ "length" --> ciLength ti , "md5sum" -->? ciMD5sum ti , "name" --> ciName ti , "piece length" --> ciPieceLength ti , "pieces" --> ciPieces ti , "private" -->? ciPrivate ti ] toBEncode ti@(MultiFile {}) = fromAscAssocs [ "files" --> ciFiles ti , "name" --> ciName ti , "piece length" --> ciPieceLength ti , "pieces" --> ciPieces ti , "private" -->? ciPrivate ti ] fromBEncode (BDict d) | Just (BList fs) <- M.lookup "files" d = MultiFile <$> mapM fromBEncode fs <*> d >-- "name" <*> d >-- "piece length" <*> d >-- "pieces" <*> d >--? "private" | otherwise = SingleFile <$> d >-- "length" <*> d >--? "md5sum" <*> d >-- "name" <*> d >-- "piece length" <*> d >-- "pieces" <*> d >--? "private" fromBEncode _ = decodingError "ContentInfo" instance BEncodable FileInfo where toBEncode tf = fromAssocs [ "length" --> fiLength tf , "md5sum" -->? fiMD5sum tf , "path" --> fiPath tf ] fromBEncode (BDict d) = FileInfo <$> d >-- "length" <*> d >--? "md5sum" <*> d >-- "path" fromBEncode _ = decodingError "FileInfo" sizeInBase :: Integer -> Int -> Int sizeInBase n b = fromIntegral (n `div` fromIntegral b) + align where align = if n `mod` fromIntegral b == 0 then 0 else 1 contentLength :: ContentInfo -> Integer contentLength SingleFile { ciLength = len } = len contentLength MultiFile { ciFiles = tfs } = sum (map fiLength tfs) pieceCount :: ContentInfo -> Int pieceCount ci = contentLength ci `sizeInBase` ciPieceLength ci blockCount :: Int -> ContentInfo -> Int blockCount blkSize ci = contentLength ci `sizeInBase` blkSize -- | File layout specifies the order and the size of each file in the storage. -- Note that order of files is highly important since we coalesce all -- the files in the given order to get the linear block address space. -- type Layout = [(FilePath, Int)] contentLayout :: FilePath -> ContentInfo -> Layout contentLayout rootPath = filesLayout where filesLayout (SingleFile { ciName = name, ciLength = len }) = [(rootPath BC.unpack name, fromIntegral len)] filesLayout (MultiFile { ciFiles = fs, ciName = dir }) = map (first mkPath . fl) fs where -- TODO use utf8 encoding in name mkPath = ((rootPath BC.unpack dir) ) . joinPath . map BC.unpack fl (FileInfo { fiPath = p, fiLength = len }) = (p, fromIntegral len) isSingleFile :: ContentInfo -> Bool isSingleFile SingleFile {} = True isSingleFile _ = False isMultiFile :: ContentInfo -> Bool isMultiFile MultiFile {} = True isMultiFile _ = False -- | Read and decode a .torrent file. fromFile :: FilePath -> IO (Result Torrent) fromFile filepath = decoded <$> B.readFile filepath