package com.espertech.esper.epl.property;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventPropertyGetter;
import com.espertech.esper.client.EventType;
import com.espertech.esper.client.FragmentEventType;
import com.espertech.esper.epl.expression.ExprEvaluator;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;
import com.espertech.esper.epl.expression.ExprNodeUtility;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
/**
* A property evaluator that considers nested properties and that considers where-clauses
* but does not consider select-clauses.
*/
public class PropertyEvaluatorNested implements PropertyEvaluator
{
private static final Log log = LogFactory.getLog(PropertyEvaluatorNested.class);
private final EventPropertyGetter[] getter;
private final FragmentEventType[] fragmentEventType;
private final ExprEvaluator[] whereClauses;
private final EventBean[] eventsPerStream;
private final int lastLevel;
private final List<String> propertyNames;
/**
* Ctor.
* @param getter property getter
* @param fragmentEventType the fragments
* @param whereClauses the where clauses
* @param propertyNames the property names that are staggered
*/
public PropertyEvaluatorNested(EventPropertyGetter[] getter, FragmentEventType[] fragmentEventType, ExprEvaluator[] whereClauses, List<String> propertyNames)
{
this.fragmentEventType = fragmentEventType;
this.getter = getter;
this.whereClauses = whereClauses;
lastLevel = fragmentEventType.length - 1;
eventsPerStream = new EventBean[fragmentEventType.length + 1];
this.propertyNames = propertyNames;
}
public EventBean[] getProperty(EventBean event, ExprEvaluatorContext exprEvaluatorContext)
{
ArrayDeque<EventBean> resultEvents = new ArrayDeque<EventBean>();
eventsPerStream[0] = event;
populateEvents(event, 0, resultEvents, exprEvaluatorContext);
if (resultEvents.isEmpty())
{
return null;
}
return resultEvents.toArray(new EventBean[resultEvents.size()]);
}
private void populateEvents(EventBean branch, int level, Collection<EventBean> events, ExprEvaluatorContext exprEvaluatorContext)
{
try
{
Object result = getter[level].getFragment(branch);
if (fragmentEventType[level].isIndexed())
{
EventBean[] fragments = (EventBean[]) result;
if (level == lastLevel)
{
if (whereClauses[level] != null)
{
for (EventBean event : fragments)
{
eventsPerStream[level+1] = event;
if (ExprNodeUtility.applyFilterExpression(whereClauses[level], eventsPerStream, exprEvaluatorContext))
{
events.add(event);
}
}
}
else
{
events.addAll(Arrays.asList(fragments));
}
}
else
{
if (whereClauses[level] != null)
{
for (EventBean next : fragments)
{
eventsPerStream[level+1] = next;
if (ExprNodeUtility.applyFilterExpression(whereClauses[level], eventsPerStream, exprEvaluatorContext))
{
populateEvents(next, level+1, events, exprEvaluatorContext);
}
}
}
else
{
for (EventBean next : fragments)
{
eventsPerStream[level+1] = next;
populateEvents(next, level+1, events, exprEvaluatorContext);
}
}
}
}
else
{
EventBean fragment = (EventBean) result;
if (level == lastLevel)
{
if (whereClauses[level] != null)
{
eventsPerStream[level+1] = fragment;
if (ExprNodeUtility.applyFilterExpression(whereClauses[level], eventsPerStream, exprEvaluatorContext))
{
events.add(fragment);
}
}
else
{
events.add(fragment);
}
}
else
{
if (whereClauses[level] != null)
{
eventsPerStream[level+1] = fragment;
if (ExprNodeUtility.applyFilterExpression(whereClauses[level], eventsPerStream, exprEvaluatorContext))
{
populateEvents(fragment, level+1, events, exprEvaluatorContext);
}
}
else
{
eventsPerStream[level+1] = fragment;
populateEvents(fragment, level+1, events, exprEvaluatorContext);
}
}
}
}
catch (RuntimeException ex)
{
log.error("Unexpected error evaluating property expression for event of type '" +
branch.getEventType().getName() +
"' and property '" +
propertyNames.get(level + 1) + "': " + ex.getMessage(), ex);
}
}
public EventType getFragmentEventType()
{
return fragmentEventType[lastLevel].getFragmentType();
}
public boolean compareTo(PropertyEvaluator otherEval)
{
return false;
}
}