module Database.EventStore.Internal.Operation.Volatile (volatile) where
import Data.ProtocolBuffers
import Data.UUID
import Database.EventStore.Internal.Command
import Database.EventStore.Internal.Operation
import Database.EventStore.Internal.Prelude
import Database.EventStore.Internal.Settings
import Database.EventStore.Internal.Subscription.Message
import Database.EventStore.Internal.Subscription.Types
import Database.EventStore.Internal.Types
volatile :: Text -> Bool -> Maybe Credentials -> Operation SubAction
volatile stream tos cred = construct (issueRequest stream tos cred)
issueRequest :: Text -> Bool -> Maybe Credentials -> Code SubAction ()
issueRequest stream tos cred = do
let req = subscribeToStream stream tos
request subscribeToStreamCmd cred req
[ Expect subscriptionDroppedCmd $ \_ d ->
handleDropped d
, Expect subscriptionConfirmationCmd $ \sid c -> do
let lcp = getField $ subscribeLastCommitPos c
len = getField $ subscribeLastEventNumber c
details =
SubDetails
{ subId = sid
, subCommitPos = lcp
, subLastEventNum = len
, subSubId = Nothing
}
yield (Confirmed details)
live sid
]
eventAppeared :: StreamEventAppeared -> Code SubAction ()
eventAppeared e = do
let evt = newResolvedEventFromBuf $ getField $ streamResolvedEvent e
yield (Submit evt)
live :: UUID -> Code SubAction ()
live subscriptionId = loop
where
loop =
waitForOr subscriptionId connectionReset
[ Expect subscriptionDroppedCmd $ \_ d ->
handleDropped d
, Expect streamEventAppearedCmd $ \_ e -> do
eventAppeared e
loop
]
connectionReset :: Code SubAction ()
connectionReset = yield ConnectionReset
handleDropped :: SubscriptionDropped -> Code SubAction ()
handleDropped d = do
let reason = fromMaybe D_Unsubscribed (getField $ dropReason d)
yield (Dropped $ toSubDropReason reason)