module LaunchDarkly.Server.Network.Eventing (eventThread) where
import Data.Aeson (encode)
import Data.Function ((&))
import Data.Tuple (swap)
import Data.IORef (newIORef, readIORef, atomicModifyIORef')
import qualified Data.UUID as UUID
import Control.Monad.Logger (MonadLogger, logDebug, logWarn, logError)
import Control.Monad.IO.Class (MonadIO, liftIO)
import Network.HTTP.Client (Manager, Request(..), RequestBody(..), httpLbs, parseRequest, responseStatus)
import Data.Generics.Product (getField)
import qualified Data.Text as T
import Control.Concurrent (killThread, myThreadId)
import Control.Monad (forever, when, void, unless)
import Control.Monad.Catch (MonadMask, MonadThrow)
import Control.Concurrent.MVar (takeMVar, readMVar, swapMVar, modifyMVar_)
import System.Timeout (timeout)
import System.Random (newStdGen, random)
import Data.Text.Encoding (decodeUtf8)
import qualified Data.ByteString.Lazy as L
import Network.HTTP.Types.Status (status400, status408, status429, status500)
import LaunchDarkly.Server.Client.Internal (ClientI, Status(ShuttingDown))
import LaunchDarkly.Server.Network.Common (tryAuthorized, checkAuthorization, getServerTime, prepareRequest, tryHTTP, addToAL)
import LaunchDarkly.Server.Events (processSummary, EventState)
processSend :: (MonadIO m, MonadLogger m, MonadMask m, MonadThrow m) => Manager -> Request -> m (Bool, Integer)
processSend :: Manager -> Request -> m (Bool, Integer)
processSend Manager
manager Request
req = (IO (Either HttpException (Response ByteString))
-> m (Either HttpException (Response ByteString))
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO (Either HttpException (Response ByteString))
-> m (Either HttpException (Response ByteString)))
-> IO (Either HttpException (Response ByteString))
-> m (Either HttpException (Response ByteString))
forall a b. (a -> b) -> a -> b
$ IO (Response ByteString)
-> IO (Either HttpException (Response ByteString))
forall (m :: * -> *) a.
MonadCatch m =>
m a -> m (Either HttpException a)
tryHTTP (IO (Response ByteString)
-> IO (Either HttpException (Response ByteString)))
-> IO (Response ByteString)
-> IO (Either HttpException (Response ByteString))
forall a b. (a -> b) -> a -> b
$ Request -> Manager -> IO (Response ByteString)
httpLbs Request
req Manager
manager) m (Either HttpException (Response ByteString))
-> (Either HttpException (Response ByteString)
-> m (Bool, Integer))
-> m (Bool, Integer)
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \case
(Left HttpException
err) -> $(Int
String
LogLevel
String -> Text
String -> String -> String -> CharPos -> CharPos -> Loc
Text -> Text
Loc -> Text -> LogLevel -> Text -> m ()
(Text -> m ()) -> (Text -> Text) -> Text -> m ()
forall a. a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
pack :: String -> Text
monadLoggerLog :: forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
. :: forall b c a. (b -> c) -> (a -> b) -> a -> c
id :: forall a. a -> a
logError) (String -> Text
T.pack (String -> Text) -> String -> Text
forall a b. (a -> b) -> a -> b
$ HttpException -> String
forall a. Show a => a -> String
show HttpException
err) m () -> m (Bool, Integer) -> m (Bool, Integer)
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> (Bool, Integer) -> m (Bool, Integer)
forall (f :: * -> *) a. Applicative f => a -> f a
pure (Bool
False, Integer
0)
(Right Response ByteString
response) -> do
Response ByteString -> m ()
forall (m :: * -> *) body. MonadThrow m => Response body -> m ()
checkAuthorization Response ByteString
response
let code :: Status
code = Response ByteString -> Status
forall body. Response body -> Status
responseStatus Response ByteString
response
serverTime :: Integer
serverTime = Response ByteString -> Integer
forall body. Response body -> Integer
getServerTime Response ByteString
response in
$(Int
String
LogLevel
String -> Text
String -> String -> String -> CharPos -> CharPos -> Loc
Text -> Text
Loc -> Text -> LogLevel -> Text -> m ()
(Text -> m ()) -> (Text -> Text) -> Text -> m ()
forall a. a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
pack :: String -> Text
monadLoggerLog :: forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
. :: forall b c a. (b -> c) -> (a -> b) -> a -> c
id :: forall a. a -> a
logWarn) (Text -> Text -> Text
T.append Text
"@@@ server time from LD was determined to be: " (Text -> Text) -> Text -> Text
forall a b. (a -> b) -> a -> b
$ String -> Text
T.pack (String -> Text) -> String -> Text
forall a b. (a -> b) -> a -> b
$ Integer -> String
forall a. Show a => a -> String
show Integer
serverTime) m () -> m (Bool, Integer) -> m (Bool, Integer)
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>>
if Status
code Status -> Status -> Bool
forall a. Ord a => a -> a -> Bool
< Status
status400
then (Bool, Integer) -> m (Bool, Integer)
forall (f :: * -> *) a. Applicative f => a -> f a
pure (Bool
True, Integer
serverTime)
else if (Status -> [Status] -> Bool
forall (t :: * -> *) a. (Foldable t, Eq a) => a -> t a -> Bool
elem Status
code [Status
status400, Status
status408, Status
status429]) Bool -> Bool -> Bool
|| Status
code Status -> Status -> Bool
forall a. Ord a => a -> a -> Bool
>= Status
status500
then (Bool, Integer) -> m (Bool, Integer)
forall (f :: * -> *) a. Applicative f => a -> f a
pure (Bool
False, Integer
serverTime)
else $(Int
String
LogLevel
String -> Text
String -> String -> String -> CharPos -> CharPos -> Loc
Text -> Text
Loc -> Text -> LogLevel -> Text -> m ()
(Text -> m ()) -> (Text -> Text) -> Text -> m ()
forall a. a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
pack :: String -> Text
monadLoggerLog :: forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
. :: forall b c a. (b -> c) -> (a -> b) -> a -> c
id :: forall a. a -> a
logWarn) (Text -> Text -> Text
T.append Text
"got non recoverable event post response dropping payload: " (Text -> Text) -> Text -> Text
forall a b. (a -> b) -> a -> b
$ String -> Text
T.pack (String -> Text) -> String -> Text
forall a b. (a -> b) -> a -> b
$ Status -> String
forall a. Show a => a -> String
show Status
code) m () -> m (Bool, Integer) -> m (Bool, Integer)
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> (Bool, Integer) -> m (Bool, Integer)
forall (f :: * -> *) a. Applicative f => a -> f a
pure (Bool
True, Integer
serverTime)
setEventHeaders :: Request -> Request
Request
request = Request
request
{ requestHeaders :: RequestHeaders
requestHeaders = (Request -> RequestHeaders
requestHeaders Request
request)
RequestHeaders
-> (RequestHeaders -> RequestHeaders) -> RequestHeaders
forall a b. a -> (a -> b) -> b
& \RequestHeaders
l -> RequestHeaders -> HeaderName -> ByteString -> RequestHeaders
forall k v. Eq k => [(k, v)] -> k -> v -> [(k, v)]
addToAL RequestHeaders
l HeaderName
"Content-Type" ByteString
"application/json"
RequestHeaders
-> (RequestHeaders -> RequestHeaders) -> RequestHeaders
forall a b. a -> (a -> b) -> b
& \RequestHeaders
l -> RequestHeaders -> HeaderName -> ByteString -> RequestHeaders
forall k v. Eq k => [(k, v)] -> k -> v -> [(k, v)]
addToAL RequestHeaders
l HeaderName
"X-LaunchDarkly-Event-Schema" ByteString
"3"
, method :: ByteString
method = ByteString
"POST"
}
updateLastKnownServerTime :: EventState -> Integer -> IO ()
updateLastKnownServerTime :: EventState -> Integer -> IO ()
updateLastKnownServerTime EventState
state Integer
serverTime = MVar Integer -> (Integer -> IO Integer) -> IO ()
forall a. MVar a -> (a -> IO a) -> IO ()
modifyMVar_ (EventState -> MVar Integer
forall (f :: Symbol) a s. HasField' f s a => s -> a
getField @"lastKnownServerTime" EventState
state) (\Integer
lastKnown -> Integer -> IO Integer
forall (f :: * -> *) a. Applicative f => a -> f a
pure (Integer -> IO Integer) -> Integer -> IO Integer
forall a b. (a -> b) -> a -> b
$ Integer -> Integer -> Integer
forall a. Ord a => a -> a -> a
max Integer
serverTime Integer
lastKnown)
eventThread :: (MonadIO m, MonadLogger m, MonadMask m) => Manager -> ClientI -> m ()
eventThread :: Manager -> ClientI -> m ()
eventThread Manager
manager ClientI
client = do
let state :: EventState
state = ClientI -> EventState
forall (f :: Symbol) a s. HasField' f s a => s -> a
getField @"events" ClientI
client; config :: ConfigI
config = ClientI -> ConfigI
forall (f :: Symbol) a s. HasField' f s a => s -> a
getField @"config" ClientI
client;
IORef StdGen
rngRef <- IO (IORef StdGen) -> m (IORef StdGen)
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO (IORef StdGen) -> m (IORef StdGen))
-> IO (IORef StdGen) -> m (IORef StdGen)
forall a b. (a -> b) -> a -> b
$ IO StdGen
forall (m :: * -> *). MonadIO m => m StdGen
newStdGen IO StdGen -> (StdGen -> IO (IORef StdGen)) -> IO (IORef StdGen)
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= StdGen -> IO (IORef StdGen)
forall a. a -> IO (IORef a)
newIORef
Request
req <- (IO Request -> m Request
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO Request -> m Request) -> IO Request -> m Request
forall a b. (a -> b) -> a -> b
$ String -> IO Request
forall (m :: * -> *). MonadThrow m => String -> m Request
parseRequest (String -> IO Request) -> String -> IO Request
forall a b. (a -> b) -> a -> b
$ (Text -> String
T.unpack (Text -> String) -> Text -> String
forall a b. (a -> b) -> a -> b
$ ConfigI -> Text
forall (f :: Symbol) a s. HasField' f s a => s -> a
getField @"eventsURI" ConfigI
config) String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
"/bulk") m Request -> (Request -> m Request) -> m Request
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= Request -> m Request
forall (f :: * -> *) a. Applicative f => a -> f a
pure (Request -> m Request)
-> (Request -> Request) -> Request -> m Request
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Request -> Request
setEventHeaders (Request -> Request) -> (Request -> Request) -> Request -> Request
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ConfigI -> Request -> Request
prepareRequest ConfigI
config
m () -> m ()
forall (f :: * -> *) a. Functor f => f a -> f ()
void (m () -> m ()) -> m () -> m ()
forall a b. (a -> b) -> a -> b
$ ClientI -> m Any -> m ()
forall (m :: * -> *) a.
(MonadIO m, MonadLogger m, MonadCatch m) =>
ClientI -> m a -> m ()
tryAuthorized ClientI
client (m Any -> m ()) -> m Any -> m ()
forall a b. (a -> b) -> a -> b
$ m () -> m Any
forall (f :: * -> *) a b. Applicative f => f a -> f b
forever (m () -> m Any) -> m () -> m Any
forall a b. (a -> b) -> a -> b
$ do
IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ ConfigI -> EventState -> IO ()
processSummary ConfigI
config EventState
state
[EventType]
events' <- IO [EventType] -> m [EventType]
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO [EventType] -> m [EventType])
-> IO [EventType] -> m [EventType]
forall a b. (a -> b) -> a -> b
$ MVar [EventType] -> [EventType] -> IO [EventType]
forall a. MVar a -> a -> IO a
swapMVar (EventState -> MVar [EventType]
forall (f :: Symbol) a s. HasField' f s a => s -> a
getField @"events" EventState
state) []
Bool -> m () -> m ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (Bool -> Bool
not (Bool -> Bool) -> Bool -> Bool
forall a b. (a -> b) -> a -> b
$ [EventType] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [EventType]
events') (m () -> m ()) -> m () -> m ()
forall a b. (a -> b) -> a -> b
$ do
UUID
payloadId <- IO UUID -> m UUID
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO UUID -> m UUID) -> IO UUID -> m UUID
forall a b. (a -> b) -> a -> b
$ IORef StdGen -> (StdGen -> (StdGen, UUID)) -> IO UUID
forall a b. IORef a -> (a -> (a, b)) -> IO b
atomicModifyIORef' IORef StdGen
rngRef ((UUID, StdGen) -> (StdGen, UUID)
forall a b. (a, b) -> (b, a)
swap ((UUID, StdGen) -> (StdGen, UUID))
-> (StdGen -> (UUID, StdGen)) -> StdGen -> (StdGen, UUID)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. StdGen -> (UUID, StdGen)
forall a g. (Random a, RandomGen g) => g -> (a, g)
random)
let
encoded :: ByteString
encoded = [EventType] -> ByteString
forall a. ToJSON a => a -> ByteString
encode [EventType]
events'
thisReq :: Request
thisReq = Request
req
{ requestBody :: RequestBody
requestBody = ByteString -> RequestBody
RequestBodyLBS ByteString
encoded
, requestHeaders :: RequestHeaders
requestHeaders = (Request -> RequestHeaders
requestHeaders Request
req)
RequestHeaders
-> (RequestHeaders -> RequestHeaders) -> RequestHeaders
forall a b. a -> (a -> b) -> b
& \RequestHeaders
l -> RequestHeaders -> HeaderName -> ByteString -> RequestHeaders
forall k v. Eq k => [(k, v)] -> k -> v -> [(k, v)]
addToAL RequestHeaders
l HeaderName
"X-LaunchDarkly-Payload-ID" (UUID -> ByteString
UUID.toASCIIBytes UUID
payloadId)
}
(Bool
success, Integer
serverTime) <- Manager -> Request -> m (Bool, Integer)
forall (m :: * -> *).
(MonadIO m, MonadLogger m, MonadMask m, MonadThrow m) =>
Manager -> Request -> m (Bool, Integer)
processSend Manager
manager Request
thisReq
$(Int
String
LogLevel
String -> Text
String -> String -> String -> CharPos -> CharPos -> Loc
Text -> Text
Loc -> Text -> LogLevel -> Text -> m ()
(Text -> m ()) -> (Text -> Text) -> Text -> m ()
forall a. a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
pack :: String -> Text
monadLoggerLog :: forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
. :: forall b c a. (b -> c) -> (a -> b) -> a -> c
id :: forall a. a -> a
logDebug) (Text -> m ()) -> Text -> m ()
forall a b. (a -> b) -> a -> b
$ Text -> Text -> Text
T.append Text
"sending events: " (Text -> Text) -> Text -> Text
forall a b. (a -> b) -> a -> b
$ ByteString -> Text
decodeUtf8 (ByteString -> Text) -> ByteString -> Text
forall a b. (a -> b) -> a -> b
$ ByteString -> ByteString
L.toStrict ByteString
encoded
()
_ <- case Bool
success of
Bool
True -> IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ EventState -> Integer -> IO ()
updateLastKnownServerTime EventState
state Integer
serverTime
Bool
False -> do
$(Int
String
LogLevel
String -> Text
String -> String -> String -> CharPos -> CharPos -> Loc
Text -> Text
Loc -> Text -> LogLevel -> Text -> m ()
(Text -> m ()) -> (Text -> Text) -> Text -> m ()
forall a. a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
pack :: String -> Text
monadLoggerLog :: forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
. :: forall b c a. (b -> c) -> (a -> b) -> a -> c
id :: forall a. a -> a
logWarn) Text
"retrying event delivery after one second"
IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ IO (Maybe ()) -> IO ()
forall (f :: * -> *) a. Functor f => f a -> f ()
void (IO (Maybe ()) -> IO ()) -> IO (Maybe ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ Int -> IO () -> IO (Maybe ())
forall a. Int -> IO a -> IO (Maybe a)
timeout (Int
1 Int -> Int -> Int
forall a. Num a => a -> a -> a
* Int
1000000) (IO () -> IO (Maybe ())) -> IO () -> IO (Maybe ())
forall a b. (a -> b) -> a -> b
$ MVar () -> IO ()
forall a. MVar a -> IO a
readMVar (MVar () -> IO ()) -> MVar () -> IO ()
forall a b. (a -> b) -> a -> b
$ EventState -> MVar ()
forall (f :: Symbol) a s. HasField' f s a => s -> a
getField @"flush" EventState
state
(Bool
success', Integer
serverTime') <- Manager -> Request -> m (Bool, Integer)
forall (m :: * -> *).
(MonadIO m, MonadLogger m, MonadMask m, MonadThrow m) =>
Manager -> Request -> m (Bool, Integer)
processSend Manager
manager Request
thisReq
Bool -> m () -> m ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless Bool
success' (m () -> m ()) -> m () -> m ()
forall a b. (a -> b) -> a -> b
$ do
$(Int
String
LogLevel
String -> Text
String -> String -> String -> CharPos -> CharPos -> Loc
Text -> Text
Loc -> Text -> LogLevel -> Text -> m ()
(Text -> m ()) -> (Text -> Text) -> Text -> m ()
forall a. a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
pack :: String -> Text
monadLoggerLog :: forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
. :: forall b c a. (b -> c) -> (a -> b) -> a -> c
id :: forall a. a -> a
logWarn) Text
"failed sending events on retry, dropping event batch"
IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ EventState -> Integer -> IO ()
updateLastKnownServerTime EventState
state Integer
serverTime'
$(Int
String
LogLevel
String -> Text
String -> String -> String -> CharPos -> CharPos -> Loc
Text -> Text
Loc -> Text -> LogLevel -> Text -> m ()
(Text -> m ()) -> (Text -> Text) -> Text -> m ()
forall a. a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
pack :: String -> Text
monadLoggerLog :: forall (m :: * -> *) msg.
(MonadLogger m, ToLogStr msg) =>
Loc -> Text -> LogLevel -> msg -> m ()
. :: forall b c a. (b -> c) -> (a -> b) -> a -> c
id :: forall a. a -> a
logDebug) Text
"finished send of event batch"
Status
status <- IO Status -> m Status
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO Status -> m Status) -> IO Status -> m Status
forall a b. (a -> b) -> a -> b
$ IORef Status -> IO Status
forall a. IORef a -> IO a
readIORef (IORef Status -> IO Status) -> IORef Status -> IO Status
forall a b. (a -> b) -> a -> b
$ ClientI -> IORef Status
forall (f :: Symbol) a s. HasField' f s a => s -> a
getField @"status" ClientI
client
IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ Bool -> IO () -> IO ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (Status
status Status -> Status -> Bool
forall a. Eq a => a -> a -> Bool
== Status
ShuttingDown) (IO ThreadId
myThreadId IO ThreadId -> (ThreadId -> IO ()) -> IO ()
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= ThreadId -> IO ()
killThread)
IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ IO (Maybe ()) -> IO ()
forall (f :: * -> *) a. Functor f => f a -> f ()
void (IO (Maybe ()) -> IO ()) -> IO (Maybe ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ Int -> IO () -> IO (Maybe ())
forall a. Int -> IO a -> IO (Maybe a)
timeout (Int -> Int -> Int
forall a. Num a => a -> a -> a
(*) Int
1000000 (Int -> Int) -> Int -> Int
forall a b. (a -> b) -> a -> b
$ Natural -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Natural -> Int) -> Natural -> Int
forall a b. (a -> b) -> a -> b
$ ConfigI -> Natural
forall (f :: Symbol) a s. HasField' f s a => s -> a
getField @"flushIntervalSeconds" ConfigI
config) (IO () -> IO (Maybe ())) -> IO () -> IO (Maybe ())
forall a b. (a -> b) -> a -> b
$ MVar () -> IO ()
forall a. MVar a -> IO a
takeMVar (MVar () -> IO ()) -> MVar () -> IO ()
forall a b. (a -> b) -> a -> b
$ EventState -> MVar ()
forall (f :: Symbol) a s. HasField' f s a => s -> a
getField @"flush" EventState
state