Package com.espertech.esper.common.internal.view.prior

Class PriorEventView

java.lang.Object
com.espertech.esper.common.internal.view.core.ViewSupport
com.espertech.esper.common.internal.view.prior.PriorEventView
All Implemented Interfaces:
View, Viewable, ViewDataVisitable, Iterable<EventBean>
public class PriorEventView extends ViewSupport implements ViewDataVisitable
View that provides access to prior events posted by the parent view for use by 'prior' expression nodes.

  • Field Details

  • Constructor Details

    • PriorEventView

      public PriorEventView(ViewUpdatedCollection buffer)
      Ctor.
      Parameters:
      buffer - is handling the actual storage of events for use in the 'prior' expression

  • Method Details

    • update

      public void update(EventBean[] newData, EventBean[] oldData)
      Description copied from interface: View
      Notify that data has been added or removed from the Viewable parent. The last object in the newData array of objects would be the newest object added to the parent view. The first object of the oldData array of objects would be the oldest object removed from the parent view.

      If the call to update contains new (inserted) data, then the first argument will be a non-empty list and the second will be empty. Similarly, if the call is a notification of deleted data, then the first argument will be empty and the second will be non-empty. Either the newData or oldData will be non-null. This method won't be called with both arguments being null, but either one could be null. The same is true for zero-length arrays. Either newData or oldData will be non-empty. If both are non-empty, then the update is a modification notification.

      When update() is called on a view by the parent object, the data in newData will be in the collection of the parent, and its data structures will be arranged to reflect that. The data in oldData will not be in the parent's data structures, and any access to the parent will indicate that that data is no longer there.

      Specified by:
      update in interface View
      Parameters:
      newData - is the new data that has been added to the parent view
      oldData - is the old data that has been removed from the parent view

    • setParent

      public void setParent(Viewable parent)
      Description copied from interface: View
      Called when the View is added to a Viewable object.
      Specified by:
      setParent in interface View
      Overrides:
      setParent in class ViewSupport
      Parameters:
      parent - is the parent that this view is a child of

    • getBuffer

      public ViewUpdatedCollection getBuffer()
      Returns the underlying buffer used for access to prior events.
      Returns:
      buffer

    • getEventType

      public EventType getEventType()
      Description copied from interface: Viewable
      Provides metadata information about the type of object the event collection contains.
      Specified by:
      getEventType in interface Viewable
      Returns:
      metadata for the objects in the collection

    • iterator

      public Iterator<EventBean> iterator()
      Description copied from interface: Viewable
      Allows iteration through all elements in this viewable. The iterator will return the elements in the collection in their natural order, or, if there is no natural ordering, in some unpredictable order.
      Specified by:
      iterator in interface Iterable<EventBean>
      Specified by:
      iterator in interface Viewable
      Returns:
      an iterator which will go through all current elements in the collection.

    • visitView

      public void visitView(ViewDataVisitor viewDataVisitor)
      Specified by:
      visitView in interface ViewDataVisitable