1 files changed, 124 insertions, 30 deletions

diff --git a/src/Network/BitTorrent/Exchange/Assembler.hs b/src/Network/BitTorrent/Exchange/Assembler.hs
index b1a80c9b..5dc7c5ca 100644
--- a/src/Network/BitTorrent/Exchange/Assembler.hs
+++ b/src/Network/BitTorrent/Exchange/Assembler.hs
@@ -1,65 +1,159 @@
+-- |
+--   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
+         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.Torrent.Piece
-import Network.BitTorrent.Exchange.Block
+import Network.BitTorrent.Core
+import Network.BitTorrent.Exchange.Block as B
 
+{-----------------------------------------------------------------------
+--  Assembler
+-----------------------------------------------------------------------}
 
+type BlockRange = (BlockOffset, BlockSize)
 type PieceMap = IntMap
 
-data Assembler a = Assembler
-  { inflightSet  :: PieceMap [BlockIx]
-  , piecePending :: PieceMap [Block a]
-  , pieceInfo    :: PieceInfo
+data Assembler = Assembler
+  { -- | A set of blocks that have been 'Request'ed but not yet acked.
+    _inflight :: Map PeerAddr (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
-  = Assembled   (Piece a)
+  = Completed   (Piece a)
   | Corrupted    PieceIx
   | NotRequested PieceIx
   | Overlapped   BlockIx
 
-empty :: PieceInfo -> Assembler a
-empty = Assembler IM.empty IM.empty
-
-inflightPieces :: Assembler a -> [PieceIx]
-inflightPieces Assembler {..} = keys piecePending
+null :: Assembler -> Bool
+null = undefined
 
-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
+size :: Assembler -> Bool
+size = undefined
 
-allowPiece :: PieceIx -> Assembler a -> Assembler a
-allowPiece = undefined
+empty :: PieceInfo -> Assembler
+empty = Assembler M.empty IM.empty
 
-insert' :: Block a -> [Block a] -> [Block a]
-insert' a (x : xs) = undefined
+allowPiece :: PieceIx -> Assembler -> Assembler
+allowPiece pix a @ Assembler {..}  = over pending (IM.insert pix bkt) a
+  where
+    bkt = B.empty (piPieceLength info)
 
-insertBlock :: Block a -> [Block a] -> Either [Block a] (Piece a)
-insertBlock  = undefined
+allowedSet :: PeerAddr -> Assembler -> [BlockIx]
+allowedSet = undefined
 
-inserta :: Block a -> PieceMap [Block a] -> (PieceMap [Block a], Maybe (Piece a))
-inserta = undefined
+--inflight :: PeerAddr -> BlockIx -> Assembler -> Assembler
+--inflight = undefined
 
--- | You should check if a returned by peer block is actually have
+--  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 -> Block a -> Assembler -> Assembler
+insert = undefined
+
+{-
 insert :: Block a -> Assembler a -> (Assembler a, Maybe (Result a))
-insert blk @ Block {..} a @ Assembler {..}
+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
+
+-}
\ No newline at end of file