net.esper.eql.agg
Class AggregationServiceFactory
java.lang.Object
net.esper.eql.agg.AggregationServiceFactory
public class AggregationServiceFactory
- extends Object
Factory for aggregation service instances.
Consolidates aggregation nodes such that result futures point to a single instance and
no re-evaluation of the same result occurs.
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
AggregationServiceFactory
public AggregationServiceFactory()
getService
public static AggregationService getService(List<ExprAggregateNode> selectAggregateExprNodes,
List<ExprAggregateNode> havingAggregateExprNodes,
List<ExprAggregateNode> orderByAggregateExprNodes,
boolean hasGroupByClause,
MethodResolutionService methodResolutionService)
- Returns an instance to handle the aggregation required by the aggregation expression nodes, depending on
whether there are any group-by nodes.
- Parameters:
selectAggregateExprNodes
- - aggregation nodes extracted out of the select expressionhavingAggregateExprNodes
- - aggregation nodes extracted out of the select expressionorderByAggregateExprNodes
- - aggregation nodes extracted out of the select expressionhasGroupByClause
- - indicator on whethere there is group-by required, or group-allmethodResolutionService
- - is required to resolve aggregation methods
- Returns:
- instance for aggregation handling