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|
-- |
-- Copyright : (c) Sam Truzjan 2013
-- License : BSD3
-- Maintainer : pxqr.sta@gmail.com
-- Stability : experimental
-- Portability : portable
--
-- Assembler is used to build pieces from blocks. In general
-- 'Assembler' should be used to handle 'Transfer' messages when
--
-- A block can have one of the following status:
--
-- 1) /not allowed/: Piece is not in download set. 'null' and 'empty'.
--
--
-- 2) /waiting/: (allowed?) Block have been allowed to download,
-- but /this/ peer did not send any 'Request' message for this
-- block. To allow some piece use
-- 'Network.BitTorrent.Exchange.Selector' and then 'allowedSet'
-- and 'allowPiece'.
--
-- 3) /inflight/: (pending?) Block have been requested but
-- /remote/ peer did not send any 'Piece' message for this block.
-- Related functions 'markInflight'
--
-- 4) /pending/: (stalled?) Block have have been downloaded
-- Related functions 'insertBlock'.
--
-- Piece status:
--
-- 1) /assembled/: (downloaded?) All blocks in piece have been
-- downloaded but the piece did not verified yet.
--
-- * Valid: go to completed;
--
-- * Invalid: go to waiting.
--
-- 2) /corrupted/:
--
-- 3) /downloaded/: (verified?) A piece have been successfully
-- verified via the hash. Usually the piece should be stored to
-- the 'System.Torrent.Storage' and /this/ peer should send 'Have'
-- messages to the /remote/ peers.
--
{-# LANGUAGE TemplateHaskell #-}
module Network.BitTorrent.Exchange.Assembler
( -- * Assembler
Assembler
-- * Query
, Network.BitTorrent.Exchange.Assembler.null
, Network.BitTorrent.Exchange.Assembler.size
-- * Construction
, Network.BitTorrent.Exchange.Assembler.empty
, Network.BitTorrent.Exchange.Assembler.allowPiece
-- * Debugging
, Network.BitTorrent.Exchange.Assembler.valid
) where
import Control.Applicative
import Control.Lens
import Data.IntMap.Strict as IM
import Data.List as L
import Data.Map as M
import Data.Maybe
import Data.IP
import Data.Torrent.Piece
import Network.BitTorrent.Core
import Network.BitTorrent.Exchange.Block as B
{-----------------------------------------------------------------------
-- Assembler
-----------------------------------------------------------------------}
type BlockRange = (BlockOffset, BlockSize)
type PieceMap = IntMap
data Assembler = Assembler
{ -- | A set of blocks that have been 'Request'ed but not yet acked.
_inflight :: Map (PeerAddr IP) (PieceMap [BlockRange])
-- | A set of blocks that but not yet assembled.
, _pending :: PieceMap Bucket
-- | Used for validation of assembled pieces.
, info :: PieceInfo
}
$(makeLenses ''Assembler)
valid :: Assembler -> Bool
valid = undefined
data Result a
= Completed (Piece a)
| Corrupted PieceIx
| NotRequested PieceIx
| Overlapped BlockIx
null :: Assembler -> Bool
null = undefined
size :: Assembler -> Bool
size = undefined
empty :: PieceInfo -> Assembler
empty = Assembler M.empty IM.empty
allowPiece :: PieceIx -> Assembler -> Assembler
allowPiece pix a @ Assembler {..} = over pending (IM.insert pix bkt) a
where
bkt = B.empty (piPieceLength info)
allowedSet :: (PeerAddr IP) -> Assembler -> [BlockIx]
allowedSet = undefined
--inflight :: PeerAddr -> BlockIx -> Assembler -> Assembler
--inflight = undefined
-- You should check if a returned by peer block is actually have
-- been requested and in-flight. This is needed to avoid "I send
-- random corrupted block" attacks.
insert :: (PeerAddr IP) -> Block a -> Assembler -> Assembler
insert = undefined
{-
insert :: Block a -> Assembler a -> (Assembler a, Maybe (Result a))
insert blk @ Block {..} a @ Assembler {..} = undefined
{-
= let (pending, mpiece) = inserta blk piecePending
in (Assembler inflightSet pending pieceInfo, f <$> mpiece)
where
f p = undefined
-- | checkPieceLazy pieceInfo p = Assembled p
-- | otherwise = Corrupted ixPiece
-}
inflightPieces :: Assembler a -> [PieceIx]
inflightPieces Assembler {..} = IM.keys piecePending
completeBlocks :: PieceIx -> Assembler a -> [Block a]
completeBlocks pix Assembler {..} = fromMaybe [] $ IM.lookup pix piecePending
incompleteBlocks :: PieceIx -> Assembler a -> [BlockIx]
incompleteBlocks = undefined
nextBlock :: Assembler a -> Maybe (Assembler a, BlockIx)
nextBlock Assembler {..} = undefined
inserta :: Block a
-> PieceMap [Block a]
-> (PieceMap [Block a], Maybe (Piece a))
inserta = undefined
-}
|
