Safe Haskell	Safe-Inferred
Language	Haskell2010

Marconi.Core.Indexer.LastEventIndexer

Description

An indexer that tracks the last event received from the source.

On rollback we can either decide to remove the last event or to keep the last one we received.

Synopsis

data LastEventIndexer event = LastEventIndexer (LastEventConfig event) (LastEventState event)
mkLastEventIndexer :: (HasGenesis (Point event), MonadIO m, MonadError IndexerError m) => LastEventConfig event -> m (LastEventIndexer event)
data LastEventConfig event = LastEventConfig FilePath Bool (Point event -> ByteString) (ByteString -> Either Text (Point event)) (event -> ByteString) (ByteString -> Either Text event) Word
data GetLastQuery a = GetLastQuery

Documentation

data LastEventIndexer event #

An indexer that only track the latest value of an event On rollback, we either delete the value or keep the one provided before the rollback, depending on the provided configuration.

Constructors

LastEventIndexer (LastEventConfig event) (LastEventState event)

Instances

Instances details

MonadIO m => Closeable m LastEventIndexer #
Instance details Defined in Marconi.Core.Indexer.LastEventIndexer Methods close :: LastEventIndexer event -> m () #
(MonadIO m, MonadError IndexerError m) => IsIndex m a LastEventIndexer #
Instance details Defined in Marconi.Core.Indexer.LastEventIndexer Methods index :: Timed (Point a) (Maybe a) -> LastEventIndexer a -> m (LastEventIndexer a) # indexAll :: (Eq (Point a), Traversable f) => f (Timed (Point a) (Maybe a)) -> LastEventIndexer a -> m (LastEventIndexer a) # indexAllDescending :: (Eq (Point a), Traversable f) => f (Timed (Point a) (Maybe a)) -> LastEventIndexer a -> m (LastEventIndexer a) # rollback :: Point a -> LastEventIndexer a -> m (LastEventIndexer a) # setLastStablePoint :: Point a -> LastEventIndexer a -> m (LastEventIndexer a) #
Applicative m => IsSync m event LastEventIndexer #
Instance details Defined in Marconi.Core.Indexer.LastEventIndexer Methods lastStablePoint :: LastEventIndexer event -> m (Point event) # lastSyncPoint :: LastEventIndexer event -> m (Point event) #
(MonadIO m, MonadError (QueryError (GetLastQuery event)) m) => Queryable m event (GetLastQuery event) LastEventIndexer #
Instance details Defined in Marconi.Core.Indexer.LastEventIndexer Methods query :: Point event -> GetLastQuery event -> LastEventIndexer event -> m (Result (GetLastQuery event)) # queryLatest :: GetLastQuery event -> LastEventIndexer event -> m (Result (GetLastQuery event)) #

mkLastEventIndexer :: (HasGenesis (Point event), MonadIO m, MonadError IndexerError m) => LastEventConfig event -> m (LastEventIndexer event) #

data LastEventConfig event #

Constructors

LastEventConfig FilePath Bool (Point event -> ByteString) (ByteString -> Either Text (Point event)) (event -> ByteString) (ByteString -> Either Text event) Word

data GetLastQuery a #

Datatype used to query the stored value of a LastEventIndexer

Constructors

GetLastQuery

Instances

Instances details

(MonadIO m, MonadError (QueryError (GetLastQuery event)) m) => Queryable m event (GetLastQuery event) LastEventIndexer #
Instance details Defined in Marconi.Core.Indexer.LastEventIndexer Methods query :: Point event -> GetLastQuery event -> LastEventIndexer event -> m (Result (GetLastQuery event)) # queryLatest :: GetLastQuery event -> LastEventIndexer event -> m (Result (GetLastQuery event)) #
type Result (GetLastQuery a) #
Instance details Defined in Marconi.Core.Indexer.LastEventIndexer type Result (GetLastQuery a) = Maybe a