Package com.espertech.esper.common.client.hook.aggfunc

Interface AggregationFunction

public interface AggregationFunction
Maintains aggregation state applying values as entering and leaving the state.

Implementations must also act as a factory for further independent copies of aggregation states such that new aggregation state holders and be created from a prototype.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final EPTypeClass
    EPTYPE
    Type information.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Clear out the collection.
    void
    enter(Object value)
    Apply the value as entering aggregation (entering window).
    Object
    getValue()
    Returns the current value held.
    void
    leave(Object value)
    Apply the value as leaving aggregation (leaving window).

  • Field Details

    • EPTYPE

      static final EPTypeClass EPTYPE
      Type information.

  • Method Details

    • enter

      void enter(Object value)
      Apply the value as entering aggregation (entering window).

      The value can be null since 'null' values may be counted as unique separate values.

      Parameters:
      value - to add to aggregate

    • leave

      void leave(Object value)
      Apply the value as leaving aggregation (leaving window).

      The value can be null since 'null' values may be counted as unique separate values.

      Parameters:
      value - to remove from aggregate

    • getValue

      Object getValue()
      Returns the current value held.
      Returns:
      current value

    • clear

      void clear()
      Clear out the collection.