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

Class TimeBatchView

java.lang.Object
com.espertech.esper.common.internal.view.core.ViewSupport
com.espertech.esper.common.internal.view.timebatch.TimeBatchView
All Implemented Interfaces:
AgentInstanceMgmtCallback, DataWindowView, View, Viewable, ViewDataVisitable, Iterable<EventBean>
public class TimeBatchView extends ViewSupport implements AgentInstanceMgmtCallback, DataWindowView
A data view that aggregates events in a stream and releases them in one batch at every specified time interval. The view works similar to a time_window but in not continuous. The view releases the batched events after the interval as new data to child views. The prior batch if not empty is released as old data to child view. The view doesn't release intervals with no old or new data. It also does not collect old data published by a parent view.

For example, we want to calculate the average of IBM stock every hour, for the last hour. The view accepts 2 parameter combinations. (1) A time interval is supplied with a reference point - based on this point the intervals are set. (1) A time interval is supplied but no reference point - the reference point is set when the first event arrives.

If there are no events in the current and prior batch, the view will not invoke the update method of child views. In that case also, no next callback is scheduled with the scheduling service until the next event arrives.

  • 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 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

    • isEmpty

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

    • 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

    • visitView

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

    • stop

      public void stop(AgentInstanceStopServices services)
      Specified by:
      stop in interface AgentInstanceMgmtCallback

    • transfer

      public void transfer(AgentInstanceTransferServices services)
      Specified by:
      transfer in interface AgentInstanceMgmtCallback

    • getViewFactory

      public ViewFactory getViewFactory()