Files
simplexmq/src/Simplex/Messaging/Server/MsgStore/STM.hs
Evgeny 7762b4d364 reduce the number of STM transactions (#1255)
* reduce the number of STM transactions

* reduce STM more

* refactor

* remove more
2024-08-09 16:38:46 +01:00

120 lines
3.4 KiB
Haskell

{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE TupleSections #-}
module Simplex.Messaging.Server.MsgStore.STM
( STMMsgStore,
MsgQueue (..),
newMsgStore,
getMsgQueue,
delMsgQueue,
delMsgQueueSize,
writeMsg,
tryPeekMsg,
peekMsg,
tryDelMsg,
tryDelPeekMsg,
deleteExpiredMsgs,
)
where
import qualified Data.ByteString.Char8 as B
import Data.Functor (($>))
import Data.Int (Int64)
import Data.Time.Clock.System (SystemTime (systemSeconds))
import Simplex.Messaging.Protocol (Message (..), MsgId, RecipientId)
import Simplex.Messaging.TMap (TMap)
import qualified Simplex.Messaging.TMap as TM
import UnliftIO.STM
data MsgQueue = MsgQueue
{ msgQueue :: TQueue Message,
quota :: Int,
canWrite :: TVar Bool,
size :: TVar Int
}
type STMMsgStore = TMap RecipientId MsgQueue
newMsgStore :: IO STMMsgStore
newMsgStore = TM.emptyIO
getMsgQueue :: STMMsgStore -> RecipientId -> Int -> STM MsgQueue
getMsgQueue st rId quota = maybe newQ pure =<< TM.lookup rId st
where
newQ = do
msgQueue <- newTQueue
canWrite <- newTVar True
size <- newTVar 0
let q = MsgQueue {msgQueue, quota, canWrite, size}
TM.insert rId q st
pure q
delMsgQueue :: STMMsgStore -> RecipientId -> STM ()
delMsgQueue st rId = TM.delete rId st
delMsgQueueSize :: STMMsgStore -> RecipientId -> STM Int
delMsgQueueSize st rId = TM.lookupDelete rId st >>= maybe (pure 0) (\MsgQueue {size} -> readTVar size)
writeMsg :: MsgQueue -> Message -> STM (Maybe (Message, Bool))
writeMsg MsgQueue {msgQueue = q, quota, canWrite, size} !msg = do
canWrt <- readTVar canWrite
empty <- isEmptyTQueue q
if canWrt || empty
then do
canWrt' <- (quota >) <$> readTVar size
writeTVar canWrite $! canWrt'
modifyTVar' size (+ 1)
if canWrt'
then writeTQueue q msg $> Just (msg, empty)
else (writeTQueue q $! msgQuota) $> Nothing
else pure Nothing
where
msgQuota = MessageQuota {msgId = msgId msg, msgTs = msgTs msg}
tryPeekMsg :: MsgQueue -> STM (Maybe Message)
tryPeekMsg = tryPeekTQueue . msgQueue
{-# INLINE tryPeekMsg #-}
peekMsg :: MsgQueue -> STM Message
peekMsg = peekTQueue . msgQueue
{-# INLINE peekMsg #-}
tryDelMsg :: MsgQueue -> MsgId -> STM (Maybe Message)
tryDelMsg mq msgId' =
tryPeekMsg mq >>= \case
msg_@(Just msg)
| msgId msg == msgId' || B.null msgId' -> tryDeleteMsg mq >> pure msg_
| otherwise -> pure Nothing
_ -> pure Nothing
-- atomic delete (== read) last and peek next message if available
tryDelPeekMsg :: MsgQueue -> MsgId -> STM (Maybe Message, Maybe Message)
tryDelPeekMsg mq msgId' =
tryPeekMsg mq >>= \case
msg_@(Just msg)
| msgId msg == msgId' || B.null msgId' -> (msg_,) <$> (tryDeleteMsg mq >> tryPeekMsg mq)
| otherwise -> pure (Nothing, msg_)
_ -> pure (Nothing, Nothing)
deleteExpiredMsgs :: MsgQueue -> Int64 -> STM Int
deleteExpiredMsgs mq old = loop 0
where
loop dc =
tryPeekMsg mq >>= \case
Just Message {msgTs}
| systemSeconds msgTs < old ->
tryDeleteMsg mq >> loop (dc + 1)
_ -> pure dc
tryDeleteMsg :: MsgQueue -> STM ()
tryDeleteMsg MsgQueue {msgQueue = q, size} =
tryReadTQueue q >>= \case
Just _ -> modifyTVar' size (subtract 1)
_ -> pure ()