Hercules.Agent.Producer

Documentation

data Producer p r

A thread producing zero or more payloads and a final value. Handles exception propagation.

Constructors

Producer

Fields

• producerQueueRead :: STM (Msg p r)
• producerThread :: ThreadId

Instances

Functor (Producer p)

Defined in Hercules.Agent.Producer

Methods

fmap :: (a -> b) -> Producer p a -> Producer p b

(<$) :: a -> Producer p b -> Producer p a

data ProducerCancelled

Constructors

ProducerCancelled

Instances

Exception ProducerCancelled

Defined in Hercules.Agent.Producer

Methods

toException :: ProducerCancelled -> SomeException

fromException :: SomeException -> Maybe ProducerCancelled

displayException :: ProducerCancelled -> String

Show ProducerCancelled

Defined in Hercules.Agent.Producer

Methods

showsPrec :: Int -> ProducerCancelled -> ShowS

show :: ProducerCancelled -> String

showList :: [ProducerCancelled] -> ShowS

data Msg p r

Constructors

Payload p

One of possibly many payloads from the producer

Exception SomeException

The producer stopped due to an exception

Close r

The producer was done and produced a final value

Instances

Functor (Msg p)

Defined in Hercules.Agent.Producer

Methods

fmap :: (a -> b) -> Msg p a -> Msg p b

(<$) :: a -> Msg p b -> Msg p a

forkProducer :: forall m p r. (MonadIO m, MonadUnliftIO m) => ((p -> m ()) -> m r) -> m (Producer p r)

forkProducer f produces a computation that forks a thread for f, which receives a function for returning payloads p.

f may produce a final result value r when it is done.

cancel :: MonadIO m => Producer p r -> m ()

Throws ProducerCancelled as an async exception to the producer thread. Blocks until exception is raised. See throwTo.

withProducer :: (MonadIO m, MonadUnliftIO m) => ((p -> m ()) -> m r) -> (Producer p r -> m a) -> m a

Perform an computation while withProducer takes care of forking and cleaning up.

withProducer (write -> write "a" >> write "b") $ producer -> consume producer

listen :: MonadIO m => Producer p r -> (p -> m a) -> (r -> m a) -> STM (m a)

joinSTM :: MonadIO m => STM (m a) -> m a

data Syncing a

Constructors

Syncable a

Syncer (Maybe SomeException -> STM ())

withSync :: (MonadIO m, MonadUnliftIO m, Traversable t) => t (Syncing a) -> (t (Maybe a) -> m b) -> m b

Sends sync notifications after the whole computation succeeds (or fails) Note: not exception safe in the presence of pure exceptions.

withBoundedDelayBatchProducer

Arguments

:: (MonadIO m, MonadUnliftIO m, KatipContext m)

=> Int

Max time before flushing in microseconds

-> Int

Max number of items in batch

-> Producer p r

-> (Producer [p] r -> m a)

-> m a

syncer :: MonadIO m => (Syncing a -> m ()) -> m ()