com.espertech.esper.epl.agg.access
Interface AggregationAccessor

All Known Implementing Classes:

AggregationAccessorFirstLastIndexNoEval, AggregationAccessorFirstLastIndexWEval, AggregationAccessorFirstNoEval, AggregationAccessorFirstWEval, AggregationAccessorLastNoEval, AggregationAccessorLastWEval, AggregationAccessorMinMaxByBase, AggregationAccessorMinMaxByNonTable, AggregationAccessorMinMaxByTable, AggregationAccessorSortedNonTable, AggregationAccessorSortedTable, AggregationAccessorWindowNoEval, AggregationAccessorWindowWEval, CountMinSketchAggAccessorDefault, CountMinSketchAggAccessorFrequency, CountMinSketchAggAccessorTopk

public interface AggregationAccessor

Accessor for access aggregation functions.

Method Summary

EventBean	getEnumerableEvent(AggregationState state, EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Return the aggregation state value consisting of a single event.
java.util.Collection<EventBean>	getEnumerableEvents(AggregationState state, EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Return the aggregation state value consisting of a collection of events.
java.util.Collection<java.lang.Object>	getEnumerableScalar(AggregationState state, EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Return the aggregation state value consisting of a collection of scalar values.
java.lang.Object	getValue(AggregationState state, EventBean[] eventsPerStream, boolean isNewData, ExprEvaluatorContext exprEvaluatorContext) Return the aggregation state value either as a scalar value or any other object.

Method Detail

getValue

java.lang.Object getValue(AggregationState state,
                          EventBean[] eventsPerStream,
                          boolean isNewData,
                          ExprEvaluatorContext exprEvaluatorContext)

Return the aggregation state value either as a scalar value or any other object.

For enumeration over scalar values or objects return an array or collection of scalar or object values.

Use the #getEnumerableEvents method to return a collection of events.

Use the #getEnumerableEvent to return a single events.

Parameters:

state - aggregation state, downcast as needed

eventsPerStream - events

isNewData - new-data indicator

exprEvaluatorContext - eval context

Returns:

return value

getEnumerableEvents

java.util.Collection<EventBean> getEnumerableEvents(AggregationState state,
                                                    EventBean[] eventsPerStream,
                                                    boolean isNewData,
                                                    ExprEvaluatorContext exprEvaluatorContext)

Return the aggregation state value consisting of a collection of events.

Parameters:

state - aggregation state, downcast as needed

eventsPerStream - events

isNewData - new-data indicator

exprEvaluatorContext - eval context

Returns:

return collection of events or null or empty collection

getEnumerableEvent

EventBean getEnumerableEvent(AggregationState state,
                             EventBean[] eventsPerStream,
                             boolean isNewData,
                             ExprEvaluatorContext exprEvaluatorContext)

Return the aggregation state value consisting of a single event.

Parameters:

state - aggregation state, downcast as needed

eventsPerStream - events

isNewData - new-data indicator

exprEvaluatorContext - eval context

Returns:

return event or null

getEnumerableScalar

java.util.Collection<java.lang.Object> getEnumerableScalar(AggregationState state,
                                                           EventBean[] eventsPerStream,
                                                           boolean isNewData,
                                                           ExprEvaluatorContext exprEvaluatorContext)

Return the aggregation state value consisting of a collection of scalar values.

Parameters:

state - aggregation state, downcast as needed

eventsPerStream - events

isNewData - new-data indicator

exprEvaluatorContext - eval context

Returns:

return collection of scalar or null or empty collection