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{-# LANGUAGE CPP #-}
{-# LANGUAGE GADTs #-}
module Connection.Tox
( module Connection.Tox
, ToxProgress(..)
) where
import qualified Connection as G
;import Connection (Manager (..), Policy (..))
import Control.Concurrent.STM
import Control.Monad
import Data.Dependent.Sum
import Data.Functor.Identity
import qualified Data.Map as Map
import Connection.Tox.Threads
import Network.Tox
import Network.Tox.NodeId
import Network.Tox.DHT.Handlers
import PingMachine
import Text.Read
#ifdef THREAD_DEBUG
import Control.Concurrent.Lifted.Instrument
#else
import Control.Concurrent.Lifted
import GHC.Conc (labelThread)
#endif
import GHC.Conc (threadStatus,ThreadStatus(..))
data Parameters = Parameters
{ -- | Various Tox transports and clients.
toxTransports :: Tox
-- | Thread to be forked when a connection is established.
-- TODO: this function should accept relevant parameters.
, onToxSession :: IO ()
}
data Key = Key NodeId{-me-} NodeId{-them-}
deriving (Eq,Ord)
instance Show Key where show = show . showKey_
{-
-- | A conneciton status that is tagged with a state type that is specific to
-- the status.
data Transient a where
IsDormant :: Transient ()
IsAwaitingDHTKey :: Transient ()
IsAcquiringIPAddress :: Transient ()
IsAcquiringCookie :: Transient ()
IsAwaitingHandshake :: Transient ()
IsAwaitingSessionPacket :: Transient ()
IsEstablished :: Transient ()
untag :: DSum Transient Identity -> G.Status ToxProgress
untag (IsDormant :=> _) = G.Dormant
untag (IsAwaitingDHTKey :=> _) = G.InProgress AwaitingDHTKey
untag (IsAcquiringIPAddress :=> _) = G.InProgress AcquiringIPAddress
untag (IsAcquiringCookie :=> _) = G.InProgress AcquiringCookie
untag (IsAwaitingHandshake :=> _) = G.InProgress AwaitingHandshake
untag (IsAwaitingSessionPacket :=> _) = G.InProgress AwaitingSessionPacket
untag (IsEstablished :=> _) = G.Established
-}
data StatefulTask st = StatefulTask
{ taskThread :: ThreadId
, taskState :: TVar st
}
launch :: String -> st -> ((st -> STM ()) -> IO ()) -> IO (StatefulTask st)
launch lbl st f = do
stvar <- newTVarIO st
tid <- forkIO (f $ writeTVar stvar)
labelThread tid lbl
return $ StatefulTask tid stvar
data SessionTasks = SessionTasks
{ accepting :: StatefulTask (G.Status ToxProgress)
, persuing :: StatefulTask (G.Status ToxProgress)
, refreshing :: StatefulTask (G.Status ToxProgress)
}
data SessionState = SessionState
{ connPolicy :: TVar Policy
, connPingLogic :: PingMachine
, sessionTasks :: TVar SessionTasks
-- , transient :: TVar (DSum Transient Identity)
}
sessionStatus :: SessionState -> G.Connection ToxProgress
sessionStatus st = G.Connection
{ G.connStatus = combinedStatus =<< readTVar (sessionTasks st)
, G.connPolicy = readTVar (connPolicy st)
, G.connPingLogic = connPingLogic st
}
combinedStatus :: SessionTasks -> STM (G.Status ToxProgress)
combinedStatus tasks = do
a <- readTVar (taskState $ accepting tasks)
p <- readTVar (taskState $ persuing tasks)
r <- readTVar (taskState $ refreshing tasks)
return $ maximum [a,p,r]
lookupForPolicyChange :: TVar (Map.Map Key SessionState)
-> Key -> Policy -> IO (Maybe SessionState)
lookupForPolicyChange conmap k policy = atomically $ do
cons <- readTVar conmap
fmap join $ forM (Map.lookup k cons) $ \st -> do
p <- readTVar (connPolicy st)
writeTVar (connPolicy st) policy
return $ do
guard $ p /= policy
return st
callbackId :: Int
callbackId = 1
-- | This function will fork threads as necessary.
setToxPolicy :: Parameters
-> TVar (Map.Map Key SessionState)
-> Key
-> Policy
-> IO ()
setToxPolicy params conmap k policy = case policy of
TryingToConnect -> do
mst <- lookupForPolicyChange conmap k policy
forM_ mst $ \st -> do
let getPolicy = readTVar $ connPolicy st
tasks <- atomically $ readTVar (sessionTasks st)
--TODO This check to determine whether to launch the accepting thread
--is probably racey.
astat <- threadStatus (taskThread $ accepting tasks)
accepting <- if astat /= ThreadRunning
then launch ("accept:"++show k)
(G.InProgress $ toEnum 0)
$ acceptContact getPolicy _accept_methods
else return $ accepting tasks
persuing <- launch ("persue:"++show k)
(G.InProgress $ toEnum 0)
$ persueContact getPolicy _get_status _persue_methods
refreshing <- launch ("refresh:"++show k)
(G.InProgress $ toEnum 0)
$ freshenContact getPolicy _get_status _freshen_methods
atomically $ do
writeTVar (sessionTasks st) $ SessionTasks accepting persuing refreshing
let routing = toxRouting $ toxTransports params
Key _ nid = k
registerNodeCallback routing $ NodeInfoCallback
{ interestingNodeId = nid
, listenerId = callbackId
, observedAddress = \ni -> return () -- TODO
, rumoredAddress = \saddr ni -> return () -- TODO
}
return ()
RefusingToConnect -> do -- disconnect or cancel any pending connection
mst <- lookupForPolicyChange conmap k policy
-- Since the 3 connection threads poll the current policy, they should
-- all terminate on their own.
--
-- Here we block until they finish.
forM_ mst $ \st -> do
atomically $ do
let routing = toxRouting $ toxTransports params
Key _ nid = k
unregisterNodeCallback callbackId routing nid
atomically $ do
tasks <- readTVar (sessionTasks st)
a <- readTVar $ taskState (accepting tasks)
p <- readTVar $ taskState (persuing tasks)
r <- readTVar $ taskState (refreshing tasks)
case (a,p,r) of
(G.Dormant,G.Dormant,G.Dormant) -> return ()
_ -> retry
OpenToConnect -> do -- passively accept connections if they initiate.
mst <- lookupForPolicyChange conmap k policy
forM_ mst $ \st -> do
let getPolicy = readTVar $ connPolicy st
accept_thread <- launch ("accept:"++show k)
(G.InProgress $ toEnum 0)
$ acceptContact getPolicy _accept_methods
atomically $ do
let routing = toxRouting $ toxTransports params
Key _ nid = k
registerNodeCallback routing $ NodeInfoCallback
{ interestingNodeId = nid
, listenerId = callbackId
, observedAddress = \ni -> return () -- TODO
, rumoredAddress = \saddr ni -> return () -- TODO
}
showKey_ :: Key -> String
showKey_ (Key me them) = show me ++ ":" ++ show them
stringToKey_ :: String -> Maybe Key
stringToKey_ s = let (xs,ys) = break (==':') s
in if null ys then Nothing
else do me <- readMaybe xs
them <- readMaybe (drop 1 ys)
return $ Key me them
toxManager :: Parameters -> IO (Manager ToxProgress Key)
toxManager params = do
conmap <- newTVarIO Map.empty
return Manager
{ setPolicy = setToxPolicy params conmap -- k -> Policy -> IO ()
, connections = fmap sessionStatus <$> readTVar conmap -- STM (Map k (Connection status))
, stringToKey = stringToKey_ -- String -> Maybe k
, showProgress = show -- status -> String
, showKey = showKey_ -- k -> String
}
|
