Package com.dehnes.kotlinredis.pubsub

Class RedisPubSubService

  • All Implemented Interfaces:
    
public final class RedisPubSubService

    An at-most-once messaging service that uses "virtual channels/topics" on top of a single Redis channel.

    This allows for grater scalability where many clients can share a single Redis connection; and automatic re-connect is handled once.

    Messages used must fit in the heap and cannot be streamed using InputStream, because a single received message is distributed/copied among all subscribers.

    Message order is preserved per publisher due to the internal buffer - not across publishers.

    Messages are not copied so be sure to not modify the ByteArray in message handlers.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Unit start(Duration timeout) Starts the service, optionally waiting for a successfully subscribe
      final Unit stop() Stops the service and waits for the background thread to finish
      final RedisPubSubServiceSubscription subscribe(List<String> channels, Integer messageBufferLimit, Function2<String, ByteArray, Unit> onMsg)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • RedisPubSubService

        RedisPubSubService(RedisConnectionPool connectionPool, String redisChannelName, Long delayBetweenReconnectMs, Integer heartbeatIntervalMs)
        Parameters:
        connectionPool - the connection pool to be used for sending PUBLISH messages
        redisChannelName - the channel to be used on Redis
        delayBetweenReconnectMs - upon connection failure, this delay causes a wait before a reconnect is initiated
        heartbeatIntervalMs - if nothing is received for this long, a PING is sent; if its reply is not received within another interval, the connection is considered dead and a reconnect is initiated

    • Method Detail

      • start

         final Unit start(Duration timeout)

        Starts the service, optionally waiting for a successfully subscribe

        Parameters:
        timeout - max time to wait for the subscribe to succeed

      • stop

         final Unit stop()

        Stops the service and waits for the background thread to finish