Package com.caplin.motif.datasource

Class CachedAdapter

java.lang.Object
com.caplin.motif.datasource.CachedAdapter
Direct Known Subclasses:
CommoditiesTradeAdapter, FXOrderAdapter, FXPrecisionAdapter, FXRatesAdapter, FXTradeAdapter, MMCalendarAdapter, MMRatesAdapter, UserDetailsAdapter
public class CachedAdapter extends Object

Provides a Single-Request, Single-Discard DataSource API for a DataProvider and simplifies the Publisher API. This class also handles multiple peer requests for the same subscription by maintaining a cache, which is useful for fail-over and redundancy scenarios.

Usage: 
 CachedAdapter adapter = new CachedAdapter(dataSource);
 CachedPublisher publisher = adapter.createActivePublisher(new NamespacePrefix("/FX"), this, new FXSubjectParser());

  • Field Details

    • dataSource

      protected final com.caplin.datasource.DataSource dataSource

  • Constructor Details

    • CachedAdapter

      public CachedAdapter(com.caplin.datasource.DataSource dataSource)
      Constructs a CachedAdapter to wrap requests made to the specified dataSource.
      Parameters:
      dataSource - The dataSource to wrap.

  • Method Details

    • createActivePublisher

      @Deprecated public <T extends SubjectInfo> CachedPublisher createActivePublisher(com.caplin.datasource.namespace.Namespace namespace, CachedDataProvider<T> dataProvider, SubjectParser<T> parser)
      Deprecated.
      Use createCachedPublisher(Namespace, CachedDataProvider, SubjectParser)
      Creates an CachedPublisher that will publish messages on the specified Namespace.

      This method uses a subject parser which allows subjects to be parsed into meaningful request objects.

      Type Parameters:
      T - The generic type erasure to provide compile time type-safety
      Parameters:
      namespace - The namespace that the publisher will publish on.
      dataProvider - The provider that will accept requests and discards.
      parser - The parser that will parse subject requests into a object representation of the request.
      Returns:
      The CachedPublisher to use for publishing messages.

    • createActivePublisher

      @Deprecated public <T extends SubjectInfo> CachedPublisher createActivePublisher(com.caplin.datasource.namespace.Namespace namespace, CachedDataProvider<T> dataProvider, SubjectParser<T> parser, boolean sendDiscardAfterError)
      Deprecated.
      Use createCachedPublisher(Namespace, CachedDataProvider, SubjectParser, boolean)
      Creates an CachedPublisher that will publish messages on the specified Namespace.

      This method uses a subject parser which allows subjects to be parsed into meaningful request objects

      Type Parameters:
      T - The generic type erasure to provide compile time type-safety
      Parameters:
      namespace - The namespace that the publisher will publish on.
      dataProvider - The provider that will accept requests and discards.
      parser - The parser that will parse subject requests into a object representation of the request.
      sendDiscardAfterError - If set to TRUE, your DataProvider will receive an immediate callback on the CachedDataProvider.onDiscard(SubjectInfo) method after you publish a failure message by calling CachedPublisher.sendNotFound(String) or CachedPublisher.sendUnavailable(String). This can be useful if you want to use the same code path to clear a cache (for example) whether a subscription is ended by the client discarding it or the back end you are integrating with no longer providing the data.
      Returns:
      The CachedPublisher to use for publishing messages.

    • createCachedPublisher

      public <T extends SubjectInfo> CachedPublisher createCachedPublisher(com.caplin.datasource.namespace.Namespace namespace, CachedDataProvider<T> dataProvider, SubjectParser<T> parser)
      Creates an CachedPublisher that will publish messages on the specified Namespace.

      This method uses a subject parser which allows subjects to be parsed into meaningful request objects.

      Type Parameters:
      T - The generic type erasure to provide compile time type-safety
      Parameters:
      namespace - The namespace that the publisher will publish on.
      dataProvider - The provider that will accept requests and discards.
      parser - The parser that will parse subject requests into a object representation of the request.
      Returns:
      The CachedPublisher to use for publishing messages.

    • createCachedPublisher

      public <T extends SubjectInfo> CachedPublisher createCachedPublisher(String metricNamePrefix, com.caplin.datasource.namespace.Namespace namespace, CachedDataProvider<T> dataProvider, SubjectParser<T> parser)
      Creates an CachedPublisher that will publish messages on the specified Namespace.

      This method uses a subject parser which allows subjects to be parsed into meaningful request objects.

      Type Parameters:
      T - The generic type erasure to provide compile time type-safety
      Parameters:
      namespace - The namespace that the publisher will publish on.
      dataProvider - The provider that will accept requests and discards.
      parser - The parser that will parse subject requests into a object representation of the request.
      metricNamePrefix - The prefix of the metric name
      Returns:
      The CachedPublisher to use for publishing messages.

    • createCachedPublisher

      public <T extends SubjectInfo> CachedPublisher createCachedPublisher(com.caplin.datasource.namespace.Namespace namespace, CachedDataProvider<T> dataProvider, SubjectParser<T> parser, boolean sendDiscardAfterError)
      Creates an ActivePublisher that will publish messages on the specified Namespace.

      This method uses a subject parser which allows subjects to be parsed into meaningful request objects

      Type Parameters:
      T - The generic type erasure to provide compile time type-safety
      Parameters:
      namespace - The namespace that the publisher will publish on.
      dataProvider - The provider that will accept requests and discards.
      parser - The parser that will parse subject requests into a object representation of the request.
      sendDiscardAfterError - If set to TRUE, your DataProvider will receive an immediate callback on the CachedDataProvider.onDiscard(SubjectInfo) method after you publish a failure message by calling CachedPublisher.sendNotFound(String) or CachedPublisher.sendUnavailable(String). This can be useful if you want to use the same code path to clear a cache (for example) whether a subscription is ended by the client discarding it or the back end you are integrating with no longer providing the data.
      Returns:
      The CachedPublisher to use for publishing messages.

    • createCachedPublisher

      public <T extends SubjectInfo> CachedPublisher createCachedPublisher(String name, com.caplin.datasource.namespace.Namespace namespace, CachedDataProvider<T> dataProvider, SubjectParser<T> parser, boolean sendDiscardAfterError)
      Creates an ActivePublisher that will publish messages on the specified Namespace.

      This method uses a subject parser which allows subjects to be parsed into meaningful request objects

      Type Parameters:
      T - The generic type erasure to provide compile time type-safety
      Parameters:
      name - The prefix that will be used on publisher metrics.
      namespace - The namespace that the publisher will publish on.
      dataProvider - The provider that will accept requests and discards.
      parser - The parser that will parse subject requests into a object representation of the request.
      sendDiscardAfterError - If set to TRUE, your DataProvider will receive an immediate callback on the CachedDataProvider.onDiscard(SubjectInfo) method after you publish a failure message by calling CachedPublisher.sendNotFound(String) or CachedPublisher.sendUnavailable(String). This can be useful if you want to use the same code path to clear a cache (for example) whether a subscription is ended by the client discarding it or the back end you are integrating with no longer providing the data.
      Returns:
      The CachedPublisher to use for publishing messages.

    • clearCache

      public void clearCache()
      Clears the cache of subscriptions and cached records. Only invoke this method when a peer down message has been received.