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

Class RankWindowView

java.lang.Object
com.espertech.esper.common.internal.view.core.ViewSupport
com.espertech.esper.common.internal.view.rank.RankWindowView
All Implemented Interfaces:
DataWindowView, View, Viewable, ViewDataVisitable, Iterable<EventBean>
public class RankWindowView extends ViewSupport implements DataWindowView
Window sorting by values in the specified field extending a specified number of elements from the lowest value up or the highest value down and retaining only the last unique value per key.

The type of the field to be sorted in the event must implement the Comparable interface.

The natural order in which events arrived is used as the second sorting criteria. Thus should events arrive with equal sort values the oldest event leaves the sort window first.

Old values removed from a another view are removed from the sort view.

  • Field Details

  • Constructor Details

  • Method Details

    • getEventType

      public final 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

    • update

      public final 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

    • internalHandleReplacedKey

      public void internalHandleReplacedKey(Object newSortKey, EventBean newEvent, EventBean oldEvent)

    • internalHandleRemovedKey

      public void internalHandleRemovedKey(Object sortKey, EventBean eventBean)

    • internalHandleAddedKey

      public void internalHandleAddedKey(Object sortKey, EventBean eventBean)

    • iterator

      public final 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.

    • toString

      public final String toString()
      Overrides:
      toString in class Object

    • getUniqueKey

      public Object getUniqueKey(EventBean theEvent)

    • getSortValues

      public Object getSortValues(EventBean theEvent)

    • getUniqueKey

      public static Object getUniqueKey(EventBean[] eventsPerStream, ExprEvaluator evaluator, EventBean theEvent, ExprEvaluatorContext evalContext)

    • getSortKey

      public static Object getSortKey(EventBean[] eventsPerStream, ExprEvaluator[] evaluators, EventBean theEvent, ExprEvaluatorContext evalContext)

    • getSortMultiKey

      public static HashableMultiKey getSortMultiKey(EventBean[] eventsPerStream, ExprEvaluator[] evaluators, ExprEvaluatorContext evalContext)

    • isEmpty

      public boolean isEmpty()
      True to indicate the sort window is empty, or false if not empty.
      Returns:
      true if empty sort window

    • visitView

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

    • getViewFactory

      public ViewFactory getViewFactory()