PostgRESTWS.HasqlBroadcast

Uses Broadcast module adding database as a source producer. This module provides a function to produce a Multiplexer from a Hasql Connection. The producer issues a LISTEN command upon Open commands and UNLISTEN upon Close.

Documentation

newHasqlBroadcaster :: ByteString -> IO Multiplexer

Returns a multiplexer from a connection URI, keeps trying to connect in case there is any error. This function also spawns a thread that keeps relaying the messages from the database to the multiplexer's listeners

newHasqlBroadcasterOrError :: ByteString -> IO (Either ByteString Multiplexer)

Returns a multiplexer from a connection URI or an error message on the left case This function also spawns a thread that keeps relaying the messages from the database to the multiplexer's listeners

acquire :: Settings -> IO (Either ConnectionError Connection)

Acquire a connection using the provided settings encoded according to the PostgreSQL format.

relayMessages :: Multiplexer -> IO ()

Reads the messages from the producer and relays them to the active listeners in their respective channels.

relayMessagesForever :: Multiplexer -> IO ThreadId

Opens a thread that relays messages from the producer thread to the channels forever