package com.espertech.esper.epl.property;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.epl.core.SelectExprProcessor;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;
import java.util.ArrayDeque;
/**
* Property evaluator that considers a select-clauses and relies
* on an accumulative property evaluator that presents events for all columns and rows.
*/
public class PropertyEvaluatorSelect implements PropertyEvaluator
{
private final SelectExprProcessor selectExprProcessor;
private final PropertyEvaluatorAccumulative accumulative;
/**
* Ctor.
* @param selectExprProcessor evaluates the select clause
* @param accumulative provides property events for input events
*/
public PropertyEvaluatorSelect(SelectExprProcessor selectExprProcessor, PropertyEvaluatorAccumulative accumulative)
{
this.selectExprProcessor = selectExprProcessor;
this.accumulative = accumulative;
}
public EventBean[] getProperty(EventBean event, ExprEvaluatorContext exprEvaluatorContext)
{
ArrayDeque<EventBean[]> rows = accumulative.getAccumulative(event, exprEvaluatorContext);
if ((rows == null) || (rows.isEmpty()))
{
return null;
}
ArrayDeque<EventBean> result = new ArrayDeque<EventBean>();
for (EventBean[] row : rows)
{
EventBean bean = selectExprProcessor.process(row, true, false);
result.add(bean);
}
return result.toArray(new EventBean[result.size()]);
}
public EventType getFragmentEventType()
{
return selectExprProcessor.getResultEventType();
}
public boolean compareTo(PropertyEvaluator otherFilterPropertyEval)
{
return false;
}
}