Package com.caplin.datasource.publisher

Interface CachingDataProvider

  • public interface CachingDataProvider

    Interface that must be implemented in order to provide data updates to DataSource peers for cached objects. It contains callbacks that handle subscription and discard requests.

    Note: the CachingDataProvider methods are not called on a dedicated worker thread. Therefore, if any of these methods are likely take a relatively long time to execute, they should be coded to run in a separate thread.

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void onDiscard​(java.lang.String subject)
      Callback that informs the DataProvider that an earlier requested subject has now been discarded.
      void onRequest​(java.lang.String subject)
      Callback that informs the CachingDataProvider that a new request has been received and it should start sending data.

    • Method Detail

      • onRequest

        void onRequest​(java.lang.String subject)

        Callback that informs the CachingDataProvider that a new request has been received and it should start sending data.

         

        The CachingDataProvider should perform the following tasks when this method is called:

        1. If that DataSource is not already subscribed to the back end system that supplies the data for this subject, the DataSource should make a subscription for the subject.
        2. When data is received from the back end system for the subject, the CachingDataProvider should call CachingPublisher.publish(com.caplin.datasource.messaging.Message) to publish the current image of the data.

          3.  

        Parameters:
        subject - The subject for this request.

      • onDiscard

        void onDiscard​(java.lang.String subject)

        Callback that informs the DataProvider that an earlier requested subject has now been discarded.

         

        Parameters:
        subject - The subject that has been discarded.