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|
{-# OPTIONS -fno-warn-orphans #-}
{-# LANGUAGE OverloadedStrings #-}
-- | This module provides torrent metainfo serialization.
module Data.Torrent
( module Data.Torrent.InfoHash
, Torrent(..), TorrentInfo(..), TorrentFile(..)
, fromFile
) where
import Control.Applicative
import Control.Monad
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
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: <http://www.bittorrent.org/beps/bep_0012.html>
, 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 :: TorrentInfo
-- ^ 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 TorrentInfo =
SingleFile {
tLength :: Int
-- ^ Length of the file in bytes.
, tMD5sum :: Maybe ByteString
-- ^ 32 character long MD5 sum of the file.
-- Used by third-party tools, not by bittorrent protocol itself.
, tName :: ByteString
-- ^ Suggested name of the file single file.
, tPieceLength :: Int
-- ^ Number of bytes in each piece.
, tPieces :: ByteString
-- ^ Concatenation of all 20-byte SHA1 hash values.
, tPrivate :: 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: <http://www.bittorrent.org/beps/bep_0027.html>
}
| MultiFile {
tFiles :: [TorrentFile]
-- ^ List of the all files that torrent contains.
, tName :: ByteString
-- | The file path of the directory in which to store all the files.
, tPieceLength :: Int
, tPieces :: ByteString
, tPrivate :: Maybe Bool
} deriving (Show, Read, Eq)
-- | Contain info about one single file.
data TorrentFile = TorrentFile {
tfLength :: Int
-- ^ Length of the file in bytes.
, tfMD5sum :: Maybe ByteString
-- ^ 32 character long MD5 sum of the file.
-- Used by third-party tools, not by bittorrent protocol itself.
, tfPath :: [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 <$> pure (hashlazy (encode info)) -- WARN
<*> d >-- "announce"
<*> d >--? "announce-list"
<*> d >--? "comment"
<*> d >--? "created by"
<*> d >--? "creation date"
<*> d >--? "encoding"
<*> d >-- "info"
<*> d >--? "publisher"
<*> d >--? "publisher-url"
<*> d >--? "singature"
fromBEncode _ = decodingError "Torrent"
instance BEncodable TorrentInfo where
toBEncode ti@(SingleFile { }) = fromAscAssocs
[ "length" --> tLength ti
, "md5sum" -->? tMD5sum ti
, "name" --> tName ti
, "piece length" --> tPieceLength ti
, "pieces" --> tPieces ti
, "private" -->? tPrivate ti
]
toBEncode ti@(MultiFile {}) = fromAscAssocs
[ "files" --> tFiles ti
, "name" --> tName ti
, "piece length" --> tPieceLength ti
, "pieces" --> tPieces ti
, "private" -->? tPrivate ti
]
fromBEncode (BDict d)
| Just (BList fs) <- M.lookup "files" d =
MultiFile <$> mapM fromBEncode fs
<*> d >-- "name"
<*> d >-- "piece length"
<*> d >-- "pieces"
<*> d >--? "private"
| otherwise =
SingleFile <$> d >-- "length"
<*> d >--? "md5sum"
<*> d >-- "name"
<*> d >-- "piece length"
<*> d >-- "pieces"
<*> d >--? "private"
fromBEncode _ = decodingError "TorrentInfo"
instance BEncodable TorrentFile where
toBEncode tf = fromAssocs
[ "length" --> tfLength tf
, "md5sum" -->? tfMD5sum tf
, "path" --> tfPath tf
]
fromBEncode (BDict d) =
TorrentFile <$> d >-- "length"
<*> d >--? "md5sum"
<*> d >-- "path"
fromBEncode _ = decodingError "TorrentFile"
-- | Read and decode a .torrent file.
fromFile :: FilePath -> IO (Result Torrent)
fromFile filepath = decoded <$> B.readFile filepath
|
