diff options
| -rw-r--r-- | src/Erebos/Flow.hs | 37 |
1 files changed, 18 insertions, 19 deletions
diff --git a/src/Erebos/Flow.hs b/src/Erebos/Flow.hs index ba2607a..1e1a521 100644 --- a/src/Erebos/Flow.hs +++ b/src/Erebos/Flow.hs @@ -11,54 +11,53 @@ module Erebos.Flow ( import Control.Concurrent.STM -data Flow r w = Flow (TMVar [r]) (TMVar [w]) - | forall r' w'. MappedFlow (r' -> r) (w -> w') (Flow r' w') +data Flow r w + = Flow (TBQueue r) (TBQueue w) + | forall r' w'. MappedFlow (r' -> r) (w -> w') (Flow r' w') type SymFlow a = Flow a a newFlow :: STM (Flow a b, Flow b a) newFlow = do - x <- newEmptyTMVar - y <- newEmptyTMVar + x <- newTBQueue 16 + y <- newTBQueue 16 return (Flow x y, Flow y x) newFlowIO :: IO (Flow a b, Flow b a) newFlowIO = atomically newFlow readFlow :: Flow r w -> STM r -readFlow (Flow rvar _) = takeTMVar rvar >>= \case - (x:[]) -> return x - (x:xs) -> putTMVar rvar xs >> return x - [] -> error "Flow: empty list" +readFlow (Flow rvar _) = readTBQueue rvar readFlow (MappedFlow f _ up) = f <$> readFlow up tryReadFlow :: Flow r w -> STM (Maybe r) -tryReadFlow (Flow rvar _) = tryTakeTMVar rvar >>= \case - Just (x:[]) -> return (Just x) - Just (x:xs) -> putTMVar rvar xs >> return (Just x) - Just [] -> error "Flow: empty list" - Nothing -> return Nothing +tryReadFlow (Flow rvar _) = tryReadTBQueue rvar tryReadFlow (MappedFlow f _ up) = fmap f <$> tryReadFlow up canReadFlow :: Flow r w -> STM Bool -canReadFlow (Flow rvar _) = not <$> isEmptyTMVar rvar +canReadFlow (Flow rvar _) = not <$> isEmptyTBQueue rvar canReadFlow (MappedFlow _ _ up) = canReadFlow up writeFlow :: Flow r w -> w -> STM () -writeFlow (Flow _ wvar) = putTMVar wvar . (:[]) +writeFlow (Flow _ wvar) = writeTBQueue wvar writeFlow (MappedFlow _ f up) = writeFlow up . f writeFlowBulk :: Flow r w -> [w] -> STM () writeFlowBulk _ [] = return () -writeFlowBulk (Flow _ wvar) xs = putTMVar wvar xs +writeFlowBulk (Flow _ wvar) xs = mapM_ (writeTBQueue wvar) xs writeFlowBulk (MappedFlow _ f up) xs = writeFlowBulk up $ map f xs tryWriteFlow :: Flow r w -> w -> STM Bool -tryWriteFlow (Flow _ wvar) = tryPutTMVar wvar . (:[]) -tryWriteFlow (MappedFlow _ f up) = tryWriteFlow up . f +tryWriteFlow (Flow _ wvar) x = do + isFullTBQueue wvar >>= \case + True -> return False + False -> do + writeTBQueue wvar x + return True +tryWriteFlow (MappedFlow _ f up) x = tryWriteFlow up $ f x canWriteFlow :: Flow r w -> STM Bool -canWriteFlow (Flow _ wvar) = isEmptyTMVar wvar +canWriteFlow (Flow _ wvar) = not <$> isFullTBQueue wvar canWriteFlow (MappedFlow _ _ up) = canWriteFlow up readFlowIO :: Flow r w -> IO r |