/**
* Creates and returns the appropriate implementation of AggregationResultHolder, based on
* aggregation function.
*
* @param function Aggregation function
* @return Appropriate aggregation result holder
*/
public static AggregationResultHolder getAggregationResultHolder(AggregationFunction function) {
String functionName = function.getName();
switch (functionName.toLowerCase()) {
case AggregationFunctionFactory.COUNT_AGGREGATION_FUNCTION:
case AggregationFunctionFactory.MAX_AGGREGATION_FUNCTION:
case AggregationFunctionFactory.MIN_AGGREGATION_FUNCTION:
case AggregationFunctionFactory.SUM_AGGREGATION_FUNCTION:
return new DoubleAggregationResultHolder(function.getDefaultValue());
default:
return new ObjectAggregationResultHolder();
}
}
/**
* Creates and returns the appropriate implementation of GroupByResultHolder, based on aggregation
* function.
*
* @param function Aggregation function
* @param maxNumResults Max number of results
* @return Appropriate group by result holder
*/
public static GroupByResultHolder getGroupByResultHolder(
AggregationFunction function, long maxNumResults) {
String functionName = function.getName();
int capacityCap = maxNumResults > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int) maxNumResults;
int initialCapacity = Math.min(capacityCap, MAX_INITIAL_RESULT_HOLDER_CAPACITY);
switch (functionName.toLowerCase()) {
case AggregationFunctionFactory.COUNT_AGGREGATION_FUNCTION:
case AggregationFunctionFactory.MAX_AGGREGATION_FUNCTION:
case AggregationFunctionFactory.MIN_AGGREGATION_FUNCTION:
case AggregationFunctionFactory.SUM_AGGREGATION_FUNCTION:
return new DoubleGroupByResultHolder(
initialCapacity, capacityCap, function.getDefaultValue());
default:
return new ObjectGroupByResultHolder(initialCapacity, capacityCap);
}
}